Digitized by the Internet Archive in 2007 with funding from IVIicrosoft Corporation http://www.archive.org/details/britishjournalof40londuoft f Supplement, British Joubval or PHorooBArHT. Jan. 5, 1894.] 2i INDEX PACtE ... 563 ... 183 ... 259 ... 702 88,114 Adams' Twin Lons Ideal Camorft ... , Aorial Pei*ppective. By Xanthn.s Smith Albnmen Bromido Papor. By W. B. Boitou Ainmininm FlasWight. By T. BoIa« ... Amateur's Backgrounds and Accessories American Notes and News 38, 101, 181, 229, 260, 32.5, 373, 493, 542, 668, 735 Amidol 42 Amidol and Metol. By A. R. Dresser 377 Amidol. By A. R. Dresser 56 midol. By George Mansfield 41 Amidol. By J. Pike 296 Amidol for Bromide Work. By S. Herliert Fry ... 86 Ammonia as a Fixing Agent. By M.Wilson 703 Ammonium Picrate for Preventing Halation 90 Amounts of Silver aiul Hypo left in Albumenised Paper at Different Stages of Washing. By P. B, Grundy and A. Hadden 511 Angle of View. By P. Everitt 357 Anglo of View. Calculation of the. By P. Everitt... 87 Another Society Wanted 386 Application of Photography to Seismology. By W. K. Burton ... ^ 203 Artistic Photography, Evolatiou of. By E. Dnnmore 589,608 Artistic Results. Some Contribntories to. By A. Horsley Hinton 21 Assistants and their Specimens 33 Auxiliary Exposure. By J. Sterry 686 Backing and Blurring. By E. Dnnmore 313 Bedford. The Lite William 36 Bees. Among the, with the Camera. By T. E. Fresh- vrater 9 Binocular Pictures. Whole-plate, and How to See them 337 Borderland. Week's Tour in the 578 Breadth. By J. K. Tnlloch, M.B 5 Breadth. By Lux 24 Broken Dishes. By W. H. Davies 56 Bromide with Various Developers. Action of ... 523 Bubbles 585 Camerastind Films. By S. Bourne Camera and the Pulpit. By Dr. A. W. Patten Camera Club Conference Camera Lncida in Micrography. Place of ... 750 ... 642 ... 250 Device to take the ... 532 Ca'ticra Studies 602 Camera Supports. By J. Pike 544 Carbon Prints. Obtaining Vigour in 778 Carbon Process. Soft Prints from Hard Kegatives by the (.09 Celluloid Films, Do they Deteriorate ? 761 Ctdluloid Films. Keeping Quiilities of. By L. Warnerke 7;<8 Celluloid : Is it Tmstworthy ? By W. B. Bolton ... 79i5 Central Photographic Club 119, 154, 171, 231, 251, 297, „ . „ 679, «ii9 Cerram. Properties of 358 Changing Boxes tosiw Dark Slides 18, 34 Chicago Exhibition Awards e;7 Chicago. Notes on a Month's Trip to. By J. .1. Steward 5:jl_ 5,(1) Chloride Papor lor Printing^)ut or Development ... 71:: Chromate of Silver 50 City and Guilds Institute and Photo-meohanical Work 2i5 Cloud Heights and Velocities. Measurements of ... 9 Clouds til Landscapes. Various Methods of Adding. By E. Dnnmore 2(>2, 213 Cobalt Printing 722 Colour Photography. Lnmiire's Experiments in ...325 PAGE Colour Photography. The Lnmiere-Lippmann. By F. E. Ives 798 Combination Printing 178 Combining Enlargements from Different Negatives 209,257 Compensation in Development for Variation in Ex- posure. By A. Cowan 390 Conference of Judges of Photographic Exhibitions ... 515 Consecutive Automatic Exposures 729 Continental Notes and News 20, 84, 894, 340, 479, 557, 5S7, 685, 780 Convention Notes 452, 476 Copying Engravings and Dravrings 219 Copyright Photographs. Illustrated Papers and ... 732 Correcting Microscopic Objectives for Photography... 473 Correction of Lenses for Photo-Micrography, Photo- graphy, and Photo-Astrograpby. Suggested Im- provement in the. By H. G. Piffard 640 Curled Gelatine Film Negatives 745 Daguerreotyping Redmwus 3"21 Daily Press on the P.S.G.B. Exhibition 623 Dark Slides, Common Defect in, and its Remedy. By Kentigern 751 Density and Colour in Collodion Emulsion. By W. B. Bolton 637 Density Ratios and Exposure. By S. Herbert Pry ... 375 D(!pres.sion in Photography 490 Depression in Photography. Some Causes of ... 354 Development. Some Points in Connexion with. By J. Sterry 456 Developer Experiments. Comparative 474 Developing Photographic Plates without the Use of a Dark Room. Apparatus for. By Alexander Watt 23 Diffused Definition : Methods of Obtaining it 681 Diffused Light 2 Discoloured Negatives 554 Dish&s and Trays. By J. Pike 40 Divers Subjects. By W. J. Stillmau 169 Dodges. By C. O. Gregory 409, 424, 496 Drying Gelatine Negatives. Rapid 289 By Ellerslie Wallace Economy in Photography. Economy in Working Editorial Table : — ABC Autotyj)e Guid^ ... ABC Toning Powder Adams's Annual Adams's Changing Box Aide-Memoire Pratique de PJiotographie "Amateur Ptuttographer" ^nnuttt, 1893 Amateur Photography. By W. L. Adams ... American Annuals Amlreseu's Developing Cartridges Andresen's Developing Outfits Andresen's Diamidophenol Anthony's Internatiorml Annual Art of Prrjection. By An Expert Baker's Tourists* Developing Tent Beresford's Accessories hiblioter.a de FotOffrafo *' Birmingham " Dry Collodion Plates Blackfriars Company's Alpenstock Stand ... Brilliantine BalTlSH JoeKNAL PUOTOOBAPHIC ALHANAC Bnrnet's Art Essays Ciwlett's Plates Challipion Folding Lamp tjhiiago Exhibition Vataloijue Chrislia ,., ... ... ... Convention Group Convention Snap Shots Vallastype Sh/tfctispcare Damp Sheet Detector Die PliOtokm'ain.ik. Kruger & Husnik Duran's Backgrounds Eastman Company's Publications Eastman Mounting Mediums Eaetmau Roller Slide Films Kdwards's Film Slides 644 , 570 299 . 364 . 532 613 . 91 , 379 . 2I>1 , 788 , 252 317 . 172 , 219 . 658 . 412 . 299 , 298 . 5« . 61 . 364 . 13 . 707 . 264 . i91 . 298 . 789 . 497 . 4«8 . 317 . 348 , 219 . 252 . 407 . 516 . 594 . 707 EniTOBiAL Table (am«nu«d) :— P«B Klementaril Photography. J. A. Hodges ^ England's Film and Dry Phite Varnish 138 Erlarifing. Einta on. By London Stereoscopic Compiny ^ Fallowfield's Annual 532 Fallowlield's Double Glass Petroleum Lamp ... 61 Flashlight Portraits. By W. E. Debenham Glycin-Aiidresen Glvcin-Haufl Gotz' Iris Diaphragms Gotz's New Stereoscopic Shutter Half RoHdaus with the Camer'i. Alfieri Kaiidbor>k of Regulations for Chicago Bxhihilion ... S7» .. 412 348,363 ... 219 ... 380 ... an K. S. 818 ... 12 ... 380 ... 789 ... 723 ... 707 ... 299 ... 317 ... 75 ... 754 ... 723 ... 299 ... 172 ... 316 ... 219 ... 298 ... 379 ... 802 ... 497 ... 13 ... 7li7 ... 251 ... 723 ... 264 ... 204 ... 61 ... 13 ... 13 ... 138 ... 763 ... 348 ... 818 ... 837 ... 412 ... 739 Jfandboofc on the Use of Compressed Oxygen. Murray Hemery's Medallion Groups Ilford Exfiosare Meter Ilford Matt P.O.P Intensity Coils. By Dyer Interchangeable Scrap Album i.tt Fotograjia ... Lomberg Dry Plates Lothian Rapid Solution Jar Lui-ema Finder • . Magic Lantern : Its Construction and Use . Marion's Bromide Lamp,., Marion's Fixing and Developing Cartridges Martial AnnaU of the City of York Mawson & Swan's Eieposure Note-book Metol-Hauff Mill's Mountant Moonlight View Mountant. P.O.P. ** Name-it" Negatioe Making. Abuey Obiin. G''ideto ... Optimus Film Hand Camera OptimiLs Opal Printing Frame Optimus Spirit Level .. Paget Opal Printing Frame Paget Print-out Opals Paulussen's Photogravures Payne's Crystal Cage Photographer's Balance Photographic Mosaics, 1893 Photographic Mosaics, 1894 Photographic Times Christmas Number ** Photography" Annual _ Photography at Night. Duchochois ... Photography Indoors and Out. Black 836 Pictoriol Effect in Photography. H. P. iobinson... 658 Political Calendar 90 Practical Photographer 61 Primus Air-tight Box 348 Professional Hetouehing Knife 109 t^upen Hand Camera SW Reliable Ventilator 75 •' Rocket " Plate 802 Roach's Improved Excelsior Hand Camera 171 Sandell Films 580 Simplex Camera Stand 318 Southern Stiidicn. A. G, Tagliaferro 837 Stereographs. By Hoi*atio Nelson King 204 Stereoscopic Views. Catalogue of 90 Talmer Hand Camera 771 The Studio 317 3'roite PrattV|ue de Phoiographie 416 Tyrer's Postal Tube 739 Una Powder 771 View Meter. Adams's 616 Vogel's Practical Pocket-book of Photography ... ',!5a Watkins's'- Junior" Biposuro Meter 548 Willis's Mounts Wratteu's Plated , Wynne's Exposure Meter Year-book 01 Photography Yeo's Photographs of Children Electrical Action of Light upon Silver .. Electric Lighting a^ .Applied to Photography. Elevating the Point of View Enamel for Iron, New English Lake Country. By T. 0. Hepworth 886 Enlargements on Prepared Canvas. By W. H. Davies 200 Enhirging 108 Enlarging Apparatus 43 Eqiuvble Temperature 665,699 Equivalent Focus of a Combination of Lenses ... 401 Exhibition, How it Strikes One 817 533 set 13 2S5 537 , 8a 177 , 613 PAOK 316 154 ... 812, 829 90 234 227 ... 2o 121 784 154 297 689 674 204 751 816 74 171 770 ... 363, 65:i ... 309, 620 en 613 251 lii 749 i-l 25 235 119 4-0 Principles 60j 73 61,97 IV ExniBlTIOKB: — Birmingham BUokhesth Bristol Ole^eland Oroyrfon Oryrtal Palace Derby Dnrham Edinbnreh Fillebrook Athentsrun Forfarshire Hackney Hamburg Lfiiof'Ster Leytonstone Liverpool Amatenr Louth and District Manchester North Middlesex Photogrraphio Salon Photographic Society of Great Britain Photographic Society of Ireland Royal Cornwall Polytechnic Society ... Sandell South London Stanley Show West Kent West London West Surrey Woolwich Etposure, Development, and Fog Exposures for Contact Bromide Prints. involved in the. By V. 0. Driffield ... Exposure Table. A New Eye and the Camera Failure. Primary Causes of. By J. Pike 7 8 Failure. Unsuspected Sources of. By W. Lindsay... 558 Fallacies Concerning Photography in the Pa«t ... 449 Films. Keeping Qualities of 555 Film Working. By W. H. Barnes 623 Finders and Cognate Subjects 601 Fixation of Negatives. The Perfect 322, 386 Fixing and Washing Silver Prints 506 Focus Lamps and other Artificial lUnminants ... 697 Forewords : On Photography as one of the Graphic Arte 689 Fourteen Years Ago. By J. Eanagaratnampillai ... 787 Frena. No. 2, for Quarter Plates 836 Prilling. By J. Pike 626 Gas in the Dark Room 634 Gelatine Prints. Intensification of 309 Gelatino-chloride Notes. By W. B. Bolton 452 Gelatino-chl'jride Paper. Development of Partly printed 672 Gelatino-chloride Paper. Development of Partly printed. By Henry Smith 687 Gelatino-chloride Paper. Double Tones in. By S. H. Fry 511 Gelatino-chloride Paper. Nature and Cause of Certain Yellow Stains on. By C. H. Bothamley ... 700 Gelatino-chloride Paper. Rapid Toning Bath for. By W. D. Wclford 408 Gelatino-chloride Papers. By E. Dockree ^S^ Gelatino-chloride Papers. Development of. By W. Lindsay 815 Gelatino-chloride Papers. Practical Remarks on. By T. N. Armstroni; 703, 770 Gelatino-chloride Paper. Treatment of ... 354, 371 Gelatino-chloride Paper. Yellow Stains on. By W. INDEX. [Supplement, British Journal of Phoiogbapht. Jan. 5, 1894. B. Bolton , 763 Gfilatino-chloride Positive Paper. Keeping Proper- ties of 521 Gelatin '-chloride Prints. Are they Permanent P ... 309 Gelalino-cbloride Prints. Toning 698 Gelstmii-chloride Prints. Toning without Gold 402, 418 Glass Positives 714 Glass PositiTea on Gelatine Plates. By W. B. Bolton 340 Qlycin. By Colonel Waterhonse 180 Goodwill in Photographic Businesses. Value of ... 81 Gradation. Inilneuce of Development on. By Hurter ■nd Driffield 248 Oraat Telescopes of the Future. By Alvan G. Clark 716 Guiacol and Allied Phenoloid Compounds. By Colonel Waterhonse 198 Gaou and Glues 274,307 Halation : A Counterblast. ByG. Markham 787 Balaton and Double Films. A Note on. By W. B, Bolton 1 Halation and Methods of Preventiufr it 506 Halation. Preventives of. B.> J. Pike 361 Hand Camera and its Use in Picture Making. By W, Ibonuu 57,72,89 Band Camera. Influence of. By W. D. Welford ... 279 Hand Camera Work and Hand Camonu. By J. K. Xnlloch „, ... 750, 7M Ha.« Pyrogallic Acid been Displaced ? By Professor H. W. Vogel W Heat in the Studio and Operating Room. Counter- acting the *•'' Heliochromy, Composite. By P. B. Ives ... 328, 344 Historical Mnseum. Plea for 7*7 HoUyer, F. Interview with. By H. Townsend ... 544 How Business may be Revived 1*^ How Louses Act. By J. H. Hargrave 736, 765 "Hydroxyl-Monohydride" ®^^ nford-P.O.P." ByJ. T. Fry 781 I uitation Photographic Engravings. By W. Lindsay 118 "In Darkest Photography — the Way Out." By Pioneer ^'"' Infants and the photographer 138, 235 Influence of Development on Gradation. By H. J. Channon ... 183,197,492 Intensification o06 Intensification. Theory and Practice of. By J. H. Bildock 217 Interchangeable Lens Screw Fittings. On the Con- struction of. By W.Taylor 509,524 Interiors, Difficult. Practical Remarks on Photo- graphing. By T. N. Armstrong ... 311, 360, 513 Interior Work. Photographing Lofty. By Edward Dnnmore ^ Inversion and Reversion of Images on the Binocular Focu-f:ing Screen 305 Isochromatio Photography 347 Is the Present Construction of Studios Wrong in Principle i" By W. H. Harrison 310 Jottings. By Cosmos 53, 85, 164, 245, 326, 454, 526, 655, 7a;, 797 Judging at Photographic Exhibitions 3S5 Kodak Gatlioring and Presentation Lantern Slide-making 721 Lautsrn Slide Making. By J. K. Tulloch 152 Lantern Slides by Printing-out 106 Lantern Slides. Viewing, by Daylight 353 Leaders : — Amatfurs' Backgrounds and Accessories ... 98, 114 Another Society Wanted 386 Assistants and their Specimens 33 Binocular Pictures. Whole-plate, and How to See them 3.37 Bromide with Various Developers. Action of ... 523 Bubbles 6a5 Camera Studies 602 Carbon Prints. Obtaining Vigonr in 778 Carbon Process. Soft Prints from Hard Negatives by the 809 Changing Boxes oersits Dark Slides 18, 34 Chloride Paper for Printing-out or Development ... 7l3 Chromate of Silver 50 City and Guilds Institute and Photo-mechanical Work 225 Combination Printing 178 Combining Eulai'gements from Different Negatives 209,257 Consecutive Automatic Btposures 729 Correctintr Microscopic Objectives for Photography 473 Curled GeUtiiie Film Negatives 74S DaguerreotypinK liedioi ns 321 Depression in Photography ... 490 Depression in Photography. Sniue Causes of ...354 Developer Experiments. Comparative 474 Diffu-ed Definition : Methods of Obtaining it ... 681 Diffused Light 2 Discoloured Negatives 554 Do Celluloid Kilms Deteriorate ? 761 Drying Gelatine Negatives. Rapid 289 Economy in Working 570 Elevating the Point of View 177 Equable Temperature 665, 699 Equivalent Focus of a Combination of Lenses ... 401 Exhibition, How it Strikes One 617 Exposure, Development, and 1 og 450 Eye and the Camera 97 Fallacies Concerning Photography in the Pafit ... 449 Films. Keeping Qualities of 555 Finders and Cognate Subjects 601 Fixation of Negatives. The Perfect 322,386 Fixing and Washing Silver Prints 506 Focus Lamps and other Artilicial Illnminauts ... 697 Gas in the Dark Room 63i Gelatino-chloride Paper. Treatment of ... .354, 371 Gelatino-chloride Positive Paper. Keeping Pro- perties of 521 Gelatino-chloride Prints. Toning 698 Gelatino-chloride Prints. Toning without Gold 402, 418 Glass Po>itiives 714 Goodwill in Photographic Businesses. Value of ... 81 Gums and (ilues 374, .307 Halation and Methods of Preventing it 505 Heat in the Studio and Operating Itoom. Counter- acting the 537 Leaders (continued) : page Historical Museum. Plea for 747 How Business may be Revived 145 Intensification ;•■ •■• 506 Inversion and Reversion of Im^es on the Binocular Focussing Screen 305 Judging at Photographic Exhibitions 385 Lantern Slides. Viewing, by Daylight ... ■•■353 Lens Fog ' i?. Lens Screens j42 Lens Standards ••■ f^ Matt Surface Prints on Ordinary Paper ... 666, b8a Metal DfTsiM Paper for Photo-lithographic Transfers 417 Mixed Developers ... 161 Mixed Developers again 522 Mixed Developing FormuliB 538 Mounts and Mountants. Testing 585 Multiple-coated Films 198 Multiple-coated Films. Experiments with ... 290, 306 Negatives from Paper Prints. Reproducing ... 49 Negatives. Improvement of 794 Non-alkaline Development ••. 34 Ontdoor Groups 338, 370 Over-Intensification of Negatives 585 Oxygen. Pure ■ 538 Panoramas, Wide Angles, and Perspective 129 Paper in Photography ... _ 729,761 Permanency of Prints. Relative 7.TO Perspective in Portraiture 257 Perspective. Some Peculiarities of 569 Pctzval Portrait Combination 777 Photo^ceramics 633 Photo-corrector. Van der Weyde's 241 Photo-crayon 649 Photo-plastigraphy 51 Photographic Piracy 745 Photographing Highly Polished Surfaces ... 618, 651 Photojrraphing Horses 98 Photographing Ice Crystals 794 Photographing Stage Scenery 113 Photography and Scientific Recording 402 Photojrraphy as a Business. Past and Present ... 323 Photo"lithography tor Amateurs 146 Photometers for Use in Printing 810,837 Printing Papers without Gloss 825 Rapid Intensification 617 Ratio of Gradation 433 Reflected Light in the Camera 634 Retouching and Varnishing 66 Reversed Neu'atives 17 Sculpturesque Photography 1 Stereo-micrography ..._ ... 65,81 Stereoscope : Impediment in Populai-ising 681 Stripping and Replacing Negatives 290 Sulphite of Soda in Development. Function of ... 489 Supplementary Exposures 650 Tele-photo Lenses. Improvements in 553 Tele-photo Lenses Past and Present 369 Varnishing and lletouching 603 Vignetting by Artificial Light 434 Warm Tones with Iron Development 130 Washing Photographs 130 Washing Thickly Coated Films 210 Welsbach Light for the Stndio 177 Wet Collodion Process 793,810,826 Wide-angle Lenses. Focal Peculiarities of 273 Lenses. Chat on 152 Lens Fog 161, 194 Lens Screens 243 Lens Standards 225 Light, Shajle, and Pietiue Composition 171 Light Waves of the Smallest Wave Lengths. Photo- graphy of 11 Liquid Air 59 Making Ready for Exhibition. By H. Maclean, P.O. S. 572 Marion's Summer Novelties 330 Matt Effects ou Albumenised Paper. By W. Lindsay. 656 MattP.O.P 800 MattP.O.P. Mr. John Howson on 816 Matt Surface Prints on Ordinary Paper ... 666,682 Mercurial Intensification. A Chemical Study of. By Chapman Jones 71 Metal versus Paper for Photo-lithographic Transfers 417 Metol and Amidol. By Colonel J. Waterhonse ... 54 Metol. By W. B. Bolton 325 Metol. Curious Experiences with. By W. B. Bolton 684 Micro-Camera. An Improved 687 Mixed Developers 161 Mixed Developers again 522 Mixed Developing Formulffi 538 Morgan & Kidd's Collotype Works. Visit to 73 Mountants. Commercial. By EUerslie Wallace ... 7 Mounts and Mountants. Testing 585 Multiple-coated Films 198 Multiple-coated Films. Experiments with ... 290, 306 Multiple-coated Films in Practice 136 Mnltipotent Camera. By T. E. Heath 263 My First Daguerreotype. By Valentine Blanchard 423,453 Naissance of Art In Photography. By A. Pringle 701, 720 National Association of Professional Photograplieni 108, 363, 738 Siiviilomcnt, BiuTiSH JouBRiLi. or Photoobapht. Jan. 5, ISOi.) INDEX. I'AOK NfituriUislio Phottvmphy. By P. IT. Kiiiorson 211,231 Niitnniliatic PhototrrAphy. Notos cm. Ky G . MauaUold 247 Neaativos. Black and White, by Artificial Liffht. By T. N. ArmstronfiT 55, 100, 166, 185 Ne^tives. Kxhibition of ^ Nopiitives from Paper Prints. Beproduoing 49 \offativo8. Improvomeut of 7W N'ogloctwl Developer. By W. B. Bolton ... UG, 149 Now Developer for Oelatino Plates. By W. P. Jenney Now Studio Nikko Paper. By J. H. Baldock Non-alkaline Development Normal and Solarising' Densities. 37i, lot 38.0 671 »4 By nu(?h Brebner 185 Northern Photojrraphic and Scientific Association ... Notes from Scotland Notes from the Capo. By C. Ray Woods \ ^ ,,,, Peculiarities in the Action of Hydm- l Pyrogallic Acid, &c. By Col. Water. Novelties in Cameras 362 On a Failure of the Law in Photojrnipby that, when tho products of the intensity of the liprht acting aud of the time of exposnre are equal, equal amounts of Chemical Action will be produced. By Captain W. de W. Abney, C.B., F.R.S 422 Optical Lantern, its Constmction and Use 10-t Optit'jil Lantern. Manipnlations of. By B. W. Parfitt , 801 Optical Truth and Visual Truth. By H. Dennis Taylor 530 Optinius Exhibition 187 Outdoor Groups 338,370 Over-intensification of Negatives 585 Oxytren. Estimation of. Haddou Oxygen. Pure By F. B. Grundy and A. 39 538 Panoramas, Wide Angles, and Perspective 129 Paper in Photography 729, 761 Para-am idophenol and Amidol. By J.«B. Bradwell... 11 Permanency of Prints. Relative 730 Perspective in Portraiture 257 Pei-spective. Some Peculiarities of 669 Petzval Portrait Combination 777 Photo-astronomy at the Cape Observatory. By C. Ray Woods 341 Photo-ceramics 633 Photo-corrector. Van der Weyde's 241 Photo-crayon 640 Photopraphers' Benevolent Association 120 Photograph ical Sophistication : its Truthfulness or Otherwise. By W. E. Debenham 656 Photographic Congress 673 PuoTOGRAPHicCoNGKESsAuxiLiABT OF THE World's Colombian Exposition : — Coarse-grained Negatives. How to Prevent. By M. A. Seed Fine Line Screen Plates and their Use. By M. Wolfe International Bureau. Desirability of. By W. J. Harrison Isochromatic Photography. By G. Onimer Medical Pliotogniphy. By Ellerslie Wallace Orthochromatic Photography. By John Carbutt Photographers* Efforts at Union. By H. Snowden Ward Photography as applied to Snrgery. By A. S. Murray Photography in a Great HospitaL By O. O. Mason 625. Photo-mechanical Processes. By W. T. Wilkinson Posing and Illumination. By E. M. E.stabrooke ... I*resent and Future Possibilities of Photography. ByL^onVidal Winter Photography in the Alps. By Mrs. E. Main Photographic Convention. By W. D. Welford Photographic Convention of the United Kingdom 368, 388 Photoghaphic Convention of the United Kino. DOM: — Anastigmatic Aplanati^5m. By Dr. Paul Rudolph 481 Artistic Kxptession with the Hand Camera. By J. Guardia 440 Co in pen wit in g in Development for Variation in Exposure. By W K. Burton 461 Convention Exhibition ... 437 iJevelopmente. Some Points in Connexion with. By C. H. Bothamloy 414 Tjante in. slide Makiof;. By C. L. Mitchell 439 Latitude in Exposnre and Speed of Plates. By Hurler and Driffield 456 Multiple Films. By S. H. Fry 442 Our Pictorial Failures. By Rev. F. C. Lambert ... 466 201 232 480 ... 261, 591 745 51 By W. H. Photoobaphic Cohvektion (con(inu«d) :— page President's Address 420 Rooont Developers. By E. J. Wall 437 Report of Photographic Club Delt^p^teH. By J. Gnardia and S. H. Fry 513 Photographio Exhibition. A Painter's View of. By Palette 670.688 Photographic Exhibitions. Suggestions for Regnlat* iug Awards at. By Edward Dnnmore 7 PnoTOOttAPHic Inijustuies: — Mcs.ir.-i. Morgan A Kirld W.Wra/s Optical Works York's Lantom-slide Factory Photographic Metastasis. By H. Brebner Photographic Piracy i^hoto-plastigraphy Photographic Standards. Some Useful. Harrison os» Photographing Highly Polished Surfaces ... 618, 651 Photogm piling Horses 98 Photographing Ice Crystals 794 Photographing Paintings by Artificial Light. By W. K. Debenham 69 Photographing Stage Scenery 113 Photographs iu Natural Colours. The Lippmann- Lumiere Process. By L. Warnerke 718 Photography and Scientific Recording 402 Photography and the Great Barrier Reef 467 Photography, Application of, to Seismology. By W. K. Burton 216 Photography applied to Journalism 297 Photography as a Bu.sine.'^s. Past and Present ... 323 Photography at Greenwich Observatory 361 Photography at the Gape Observatory. By 0. Ray Woods 214 Photogiiiphy at the Technical Schools, Manchester. By W. T. Wilkinson 6 Photography in Natural Colours 668 Photography iu Physical Research 10 Photography in Relation to the Art of Printing. By J. H. Alabaster 104 Photography of the Luminous Rays of the Shortest Wave Lengths. By Victor Schumann. 705, 738, 752, 769, 833 Photography without an Objective. By A. C. Ponton 311 Photogi-avure 52, 120, 135 Photo-lithography for Amateurs 148 Photo-lithography. W. E. Debenham 295 Photometers for Use in Printing 810,827 Photo-telescope, New, at Greenwich 572 Photo-zinco in Half Tone. By W. T. Wilkinson ... 800 Physical Development. By H. Schuauss 314 Pictorial Modification of Photographic Perspective. By H. Van der Weyde 276 Pinhole Society's Outing. By Tom Coan 26 Plate Speeds. Determination of. By Alexander Cowan 262 Plate Speeds. Determination of. V.C.Driffield Plate Speeds. Determination of. By F. Hurter and 118 By G. F. Williams 57, 69, 231 Platinotype. By J. V. Brewer 544 Plutinotype Up to Date 74 Portable Stand 658 Printing, Intensification. Copying, and Halation. By H. N. King 782 Printing Papers without Gloss 825 Printing Process for Amateurs. A Seasonable. By W.B.Bolton 19,53 Process-work. How to Make Pen and Ink Drawings for. By A. J. Gough 5 Professional Photography. Position of. By Thomas FaU 733 Professional to Professionals. By John Stuart ... 830 Rapid Solution Making 100 Rjipid Intensification 617 Rjitio of Gradation on Positive Papers. Bj W. B. Bolton 476 Ratio of Gradation 433 Reducing Over-printed Gelatine Proofs. By W. Lindsay 275 Rcfiecteil Light in the Camera .. 634 Restoring Foggy Plates. By W. B. Bolton 214 ReUmchin^ aud Varnif^hes. By Uaynes Welch ... 117 Retouching and Varuishing 66 Retouching. By £. C. Morgan 280 Retouching. By W. Parry 24i Reversed Negatives 17 Rcverstil Negatives. By George Mansfield 41 Reversed Negatives. By W. Bishop , 389 Rocket Phite 658 Rollabla FilmF. Development of 151 Rough Paper. By Henry W. Bennett 186 Ruled versus GranuUr OratingB. By W. Lindiay ... 1S2 Bye and Winohelsea with the Camera 60 ... 719, 737 ... I 497 ... 313, 327 By Prof. G. fti2 41 573 150 164 Hinton Speed of Plates. Elder A Criticism and Reply. Solon. A Painter's View of. By Ptflette Scnlpturostiuo Photography Seasonable Novelties Selections. By E. Dnnmore Sensitiveness of Photographic Plates. W. Hough Silver Chlorides. Notes on. By M. Carey Lea Silver. Notes on. By M. Carey Lea Soap Bubbles in the Studio. By Harry Smith, F.I.O. Solio Paper. Toning of. By J. B. B. Wellington .. Solution Making. By G. W. Webster Specialisation in Fine Art Work. By A* Horsley 133 By H. M. ... 785, 799 Spirit Photography (it Spirit Photography, with Remarks on Flnorest^nco. By J. Traill Taylor 167 Spots and Pinholes. By E. Dnnmore 559 Statuary Portraiture 85 Stereography. Elementary. By Thomas Bsdding ... 638 Stereo- micrography 66, 81 Stereoscope and Stereoscopic Photography. By J. A. Bntler 137,151 Stereoscope: Impediment in Popularising 681 Stereoscopic Photography. By W. I. Chadwick ... 454 Stereoscopy. By W. I. Chadwick 529 Stops of Lenses. A System of Measuring and Num- bering the. By Dr. P. Rudolph 83') Stripping and Replacing Negatives 290 Studio BaUding. By G. W. Webster 148, 196, 293, 374 Studio Building. Notes on. By W. Coles 358 Studio Heating. By G. W. Webster 37 Sulphite of Soda in Development. Function of ... 489 Summer Novelties iu Apparatus 378, 391, 410 Supplementary Exposures 650 Supplementary Lighting. By K. Dnnmore 508 Tele-photo Lens. New 315 Tele-photo Lenses, Improvements in 563 Tele-photo Lenses Past and Present 368 Tele-photo Systems of Moderate Amplification. By T. R. Dallmeyer 477 Tele-photography. By T. R. Dallmeyer ... 766, 782 Testing Photogiaphic Objectives. By Dr. A. Miethe 779 Theories of Development. By John H. Janeway . 134 Things in General. By Free Lance 4, 115, 213, 357, 496, 606, 717, 814 Tinfoil as a Support for Photo-litht^raphic Transfers. By Captain A. M. Mantell, R.K 406 Tour in the Himalayas aud on the North-west Fron- tier. Notes on. By F. St. J. Gore 515 Transylvanian Alps. ByM. deDechy 832 Variations in the Metol Developer. By W. B. Bolton 604 Various Snbjects. By J. R. Hopwood 309 Varnishing and Retouching 603 Vignetting by Artificial Light 434 Vitro-Enaiuelliug. Preparation of Tablets for. By A. Haddou 642 Waltham Cross. By Tom Coan ... 531 Warm Tones with Iron Development 130 Washing Photographs 130 Washing Thickly Coated Films 210 Water in Development 363 Watson's Cameras for the Season 347 Weakncs.s of Strong Points. By Hector Maclean ... 132 *' Well " Developing Dish 83 Welsbach Light for the Studio 177 Wot Collodion. By W. E. Debenham 670 Wot Collodion Process 793, 810, 826 Wide-angle and Telephotogniphic Lenses. Com- parative Advantages of. By T. R. Dallmeyer ... 101 Wide-angle Lenses. Focal Peculiarities of 273 Wilson. The late G. W 165 Winter Phot<^raphy 40 Winter Photography. By W. T. Wilkinson 8 Winter Troubles. By Old Collodion 21 Winter Woes and their Remedies. By 0. B. Bamoa . 833 [Supplement, BhJtise Jopbnai. of Photookapht. Jan. 5, 1894. AUTHORS' INDEX. AnsET, Captain W. de W., C.B., F.E.S.— On n Failure of tho Law in Photogrnphy that, when the Products of the Intensity of tho Lii^ht acting and of the time of ExpOBore are eqnal, eqnal amounts of chemical action will be produced ... 422 Alabaster, J. H.— Photography in its Relation to Printing 104 Abhstsono, T. N.— Black and White Negatives by means of Artificial Light 5t, 101, 166, 185 Oelatino.chloride Papers 703, 770 Photographing DifBcnlt Interiors ... 312,360,512 Baldock, J. H., F.O.S.— Intensification Niklco Paper Babnks, C. B.— Winter Woes and their Remedies Baenes, W. H.— Film Working Bbddihq, Thomas— Elementary Stereography Bbsbtett, H. W. — Bough Paper Bishop, W.— Rerersed Negatives Blabchabd, Valentine — My First Daguerreotype Bolas, T.— Aluminium Flafihlight Bolton, W. B.— Albumen Bromide Paper for Contact Printing Deiuity and Colour in Collodion Emulsion ... 6elatino.chloride Notes Gla^R Positives on Gelatine Plates L Halation and Double Films Is Celluloid Trustworthy ? Motol Neglected Developer Ratio of Gradation on Positive Papers Restorinsr Foggy Plates Seasonable Printing Process Some Carious Experiences with Metol ... Variationfl in the Metol Developer "Well '* Developing Dish Yellow Stains on Gelatino.chljride Paper ... 217 671 ... 623 186 389 B0TLEB, J. A. — Stereoscope and Stereoscopic Photography.. Carbutt, J. — Orthochromatic Photography Chadwick, W. 1.— Stereoscopic Photography StereoBcopy Channon, H. J.— Influence of Development on Gradation ^lark, Alvan G. — Great Telescopes of the Future COAN, T.— Pinhole Society's Outing Waltham Cross Coles, W.— Studio Building FADE 137, 151 ... 576 ... 451 ... 529 183, 197, 492 716 24 531 COSKOB — Jottings 53, 85, 164, 245, 326, 454, 526, 655, 733, 797 423, 453 ... 702 ... 637 ... 452 ... 339 ... 4 ... 766 ... 325 116, 149 ... 476 ... 244 19,53 ... 684 ... 604 ... 83 ... 763 Cowan, A.— Compensation in Development for Variation Kxposure Determination of Plate Speeds Cbaheb, G. — Isochromatic Photography Dallueteb, T. R.— Tele-pbotograpbic Systems of Moderate Amplifica- tions Tele-photography Wide-angle and Tele-photographic Lenses ... Datibs, W. H.— Broken Dishes Enlargements Printed oh Prepared Canvas... Debenham, W. E. — Photograpbical Sophistication Photographing Paintings by Artificial Light Photo-lithography Wot Collodion De Decht, M. — Trausylvanian Alps DOOEBEE, E. Qelatino-chloride Papers , 578 477 766,782 ... 102 56 200 295 670 832 056 Estabrooke, E. M.— Posing and Illumination EVERITT, P. — Angle of View Fall, T.— Position of Professional Photogi-aphy page ... 593 87,357 ... 733 Free Lance— On Things in General 4, 115, 213, 357, 495, 606, 717, 814 Fbeshwateb, T. E., F.R.M.S.— Among the Bees with the Camera Fbt, J. T.— nford Printing'^nt Paper Fbt, S. H.— Amidol for Bromide Work Density Ratios and Exposure Double Tones in Gelatino-ohloride Papers Multiple Films GOUGH, A. J. — Pen-and-ink Drawings for Process Work Gbeooet, C. D. — Dodges 10 7<1 ... 375 ... 611 ... 442 409,496 Gbcndt, F. B. and Haddoh, A.— Amounts of Silver and Hypo left in Albumenised Paper at Different Stages of Washing Estimation of Oxygen GCTARDIA, J. — Artistic Expression with tho Hand Camera... 511 39 440 BOTBAHLXT, 0. H.— Nature and Cause of Certain Yellow Stains on Gelatino-chloride Paper 700 Points in Connexion with Development 444 BODBBE, 8.— Camenu and Films Bbadwell, J. B.— Par«roidophono] and Amidol ... Brebner, Huoh— Normal and SoUrlsing Densities Photo^phio MetutMis BRBWm, J. V. — FlatiBotype 5*4 Bdbtos, Pbopessor W. K.— Applioatian of Photography to Seismology 203, 216 On the Power of Compensating in Development for Variation in Exposure 461 DbESSER, A. R.— Amidol SS, 377 750 185 261, 493, 591 Driffield, Vero C. — Principles Involved in the Calculations of Ex- posures for Contact Prints on Bromide Papers ... 600 DOSMOBE, E.— Backing and Blurring 3^ Evolution of Artistic Photography 589, 608 Methods of Adding Clouds to LaiuUcapes ... 202, 213 Photographing Ijofty Interior Work 8 Regulatiug Awards at Photographic Exhibitions ... 7 GnAEDiA, J., and S. H. Fet— Plymouth Convention. Report of the Photographic Club Delegates S12 Haddon, a. — Tablets for Vitro-Ennmelling 643 Habgbave, J. H. — How Lenses Act 736, 765 Harrison, W. H. — Is the Present Construction of Photographic Studios Wrong in Principle ? 310 Useful Photographic Standards 588 Harrison, W. Jerome — International Bureau 543 Heath, T. E.— Mnltipotent Camera 263 Hepworth, T. C. — English Lake Country 686 Hinton, a. Horslet— Specialisation in Fine-Art Work 133 Selections Spots and Pinholes Supplementary Lightiug... Elder, H. M.— Speed Of Plates : A Criticism and Reply Emerson, P. H.— Naturalistic Photography 313, 327 ... 559 ... 508 785,799 21.1, 231 HopwooD, J. R. — Notes on Various Subjects HotjOB, Prof. G. W.— Sensitiveness of Photographic Plates... HUBTER, F., AND DRIFFIELD, V. C. — Det<.>rmi nation of Plate Speeds Influence of Development on Gradation Latitude in Exposure and Speed of Plates .309 118 248 456 Ives, F. E.— Composite Heliochromy 328,344 Lumi^re & Lippmanu Colour Photography 798 Bnpplomcnt. IlKiTisu Joi'KKAi. Ok I'HOTOiiEirui. Jaii. S, 1804.] AUTHOIIS' INDEX (Contttmeil). rAOt Jasbwat, J. H.. M.D.— Theoriea of Development 13j JiHHKT, W. p.— Kcw Developer for Oelatine FUtot 374. 404 JoviiS. Obapuan— Ohemiool Study of MerourUl Intensifloation ... 70 XASAOAKATNAUriLLAI, S. — Fourteen Years Ago 787 KiHO, H. N.— I Printing, Intensifloation, Copying, and Halation ... 782 Lahbkrt, llRV. F. C— Our Pictorial Failures 466 Lka, M. Caret— Notes on Silver Sf Silver Chloride ■« LlSDSAT, W.— Gelatino-chloride Paper. Development of 815 Imitation Plioto-engravinffS llf Matt Effects on Albumenised Paper 656 KeducinK Over-printed Gelatine Proofs 275 Ruled v«rsu£ Granular Gratings 182 Unsnapec'ed Sonroes of Failure 558 "Lux"— Breadth 24 MACKir, A. — Photojrraphy in Wai'fare 748 Maclean, Hector — Making R<;a ty for Exhibition 572 Weakness of " Strong Points " 132 Main, Mrs. E. — Winter Photography in the Alps 545 Mansfield, George— Nataralistio Photography 247 Reversed Negatives — Amidol 41 Manteix, a. M. — Tinfoil as a Support for Photo-litho Trausfors ... 406 Mareham, 0., M.D.— Halation : A Counterblast 787 Mason, 0. O.— Photography in a Great Hospital 625,641 MiETUE, Db. a. — Practical Testing of Photographic Objectives ... 779 Mitchell, Charles L. — Ijantem-8lide Making 439 MORItAN, K. C. — RetouchiDK 280 MoiEB, C. W.— Statuary Portraiture 85 MnRRAT, A. S.— Photography as Applied to Surgery 592 Palette. — Painter's View of the Photographic Exhibition 670, 6e8, 719, 737 Parfitt, E. W.— Manipulations of the Optical Lantern 801 Paitiik, R«t. A. W.— Camera ud the Pnlpit S42 PiFFARD, H. G.— Correction of Lenses for Photo-micrography, Photo- graphy, Ac 640 ?IK«, J.— I Amidol for Developed Prints 296' Camera Supports 544 Dishes and Trays 40 Frilling WB I Preventives of Halation 861 Primary Causes of Failure 718 { •PlONEEB** — " In Darkest Photography— The Way Out " i?ohtoh, a. 0. — Photography Without an Objective SIJ Parry, W.— Keloucbing ... ... 246 ?okteb, T. C— Peculiarities in the action of Hydroquinone, Pyro- gallic Acid and Water on Gelatine Plates ... 341 PiusaLB, Ahdbew — Naissanoe of Art in Photography 701,720 IlCDOLPH, Dr. P. — Anastigmatic Aplanatism and the Zeiss Anastigma- tic Lenses .. ... 481 Measuring and Numbering the ftops of Photo- graphio Lenses 830 SCBBADSS, HeRHANH — Physical Development 314 Schumann, V. — On the Photography of the Lnminotts Rays of the Shortest Wave Lengths ... 705, 738, 752, 76a, 833 Seed, M, A. — Coarse-grained Negatives- How to Prevent them . 57£ 687 573 Smith, H.— Developed Gelatino-chloride Printing-ont Paper . Smith, H.. F.C.S.— Soap Bubbles in the Studio Smith, Xanthos— Aerial Perspective 183 Sterbt, J. — Auxiliary Exposure 686 Some Points in Connexion with Development ... 456 Steward, J. J. — Trip to Chicago 531 Stilluan, W. J. — Divers Subjects 169 St. Jobk Gobi, F.— Tour in the Himalayas 515,560 Stdabt, Jobk— A Professional to Professionals 832 Taylob, H. Dennis — Optical Trnth and Visual Truth Jia Tatlob, J. Tbaill- Spirit Photography : with Remarks on Fluores- cence 167 Tatlob, W.— Constrnction of Interchangeable Lena Screw Fit- tings 509,524 Thomas, W.— Band Camera and its Use in Picture Uaking 57, 72, 89 rowasEMU, Uobace— Art In Photography ruLLocB, J. K.— Breadth Hand Camera Work and Hand Cameras Lantern-slide Making 7ani>ebwetde, H.— Pictorial Modification of Photographic Perspective. 276 ^IDAL, Leon — Present and Future Possibilities of Photography ... 548 VI; rAOB .. 544 ... 6 750,764 ... 1S2 AOQEL, Prof. H. W.— Hujs Pyrogallic Acid been Displaced ? Yall, E. J.— Recent Developers Wallace, Ellebslik — Commercial Mountants Economy in Working Medical Photography Yard, H. S.— Photographers' Efforts at Union ... 67 ... 487 ... 7 ... 644 ... 577 ... 561 Vabhebke, L. — Celluloid Films, Keeping Qualities of 788 Photographs in Natural Colours by the Lippmann- Lnmiure Process 718 /atebhouse. Colonel — Glyoin ig( Gnaiacol and Allied Phenoioid Compounds aa Developers igg Metol and Amidol 54 ,/att, Alexander — Apparatus for Development without a Dark Room 23 /ebster, Q. W. — Rapid Solution Making ... Solution Making Studio Building Studio Heating Velch, Hatnes— Retouching and Varnishing , 101 164 148, 196, as, 372 37 117 Yelfobd, W. D.— Inllnence of the Hand Camera 279 Photographic Convention 543 Rapid Toning Baths for Gelatino-Chloride Paper ... 406 Wellington, J. B. B.— Toning Solio Paper 150 Wilkinson, W. T.— Photography at the Municipal Technical Schools, Manchester g Photo-mechanical Processes 623 Photo-zinco in Half Tone gOO Winter Photography „ ... g Williams, G. F.— Determination of Plate Speeds Wilson, Mattbew— Ammonia as a Fixing Agent Week's Tour in the Borderland Wolfe, M.— Fine Line Screen Plates and their Use Woods, C. Rat— Notes from the Cape Photography at the Cape Observatory ... 56, 69, 229 ... .. 708 578 574 ... 170 214,341 (Supplement, British Jocknal of Photographt. Jar. 5, 1894. THE LANTEEN EECOED (Monthly Supplement to The BiirriSH Journal of Photoobaphy. ) JANUARY— DECEMBER, 1893. American and English Lantern Practice. Notes on. By Edmund Stirling 84 Announcement 41 Archer's Combined Hand or Stand Camera 64 Beard's New Cut-otf Jet 53 Blow-Ihrough Jet. An Improved 48 Brin's Oxygen Works. Visit to 41 Bursting of a Cylinder at Bradford 119 Capabilities of Photography 93 Carriers. By James Lewis 107 Chadwick's Lantern Specialities 78 Cfcaritable Lantern Entertainment Society ... 28, 118 CoUodio-ehloride Lantern Slides. By W. B. Bolton . 100 Colloclion Process. An Essay. By W. B. Bolton ... 106 Collodion Transparencies by Contact, By W. B, Bolton 26 Colour Photography 85 Coloured Lantern Slides 71 Combination Lantern for the Dark Room 90 Cqpyinff Photographs by Artificial L'ght. By F. W. Parrott Catting Lantern Masks. By W. B. Bolton 50 DissolTor. The. By Ferrers Oxley 60 Double FrintingforTransparencies. By W. B. Bolton. 59 Enlarging by Daylight 94 Enrichment of Coal Gas by the Hydro-oxy Process... 119 Ether Satnrators. By F. E. Ives 28 Explosions. Possible Causes of 90 Explosive Gaa in Hot Water Apparatus 95 Farm-life on the Screen 39 Flexible Metallic Tubing 46 Gas Cylinders and Explosions. By W. I. Chadwick... 118 How Gas Oylindera are Made. By G. B. Baker ... 113 Incandescent Electric Light in the Lantern. By C. Ray Woods 76 Induration of the Gelatine Film. By W. P. Jennoy . 77 Iron Carbonyl in Compressed CJai*. By Lewis Wright 58 PAGE Lantern and Stereoscope as Aids to Edncation ... 103 Lantern Apparatus. Recent Novelties in. 31, 101, 111, 116 Lantern Experiments. By W. I. Chadwick Lantern in Japan Lantern in Scientific Stage Eifects 88 Lanteioi Matters at the Cape. By 0. Ray Woods ... 45 Lantern Mems. By G. R. Baker. 27. 34, 44, 50, 60, 67, 75, m, 91, 98, 109. 117 Lantern Nights at the Photographic Society's Exhi- bition 104 Lantern Notes and News 25, 33, 43, 49, 57, 65. 73, 81, 89, 97. 105, 113 Lantern Patents 48, 56,64, 120 Lantern Queries ... ... .32, 40, 56, 64, 80, 88, 96, 120 Lantern Slide and its Relations to Art. By H. J. Newton 37 Lantern Slide Emulsion 96 Lantern Slide Making in Foochow 31 Lantern Slide Making. Simplicity of. By H. S. Nutt 55 Lantern Slide Masks. Shapes of 33 Lantern Slide Methods. By C. W. Barnes 36 Lantern Slides, by the Wet Collodion Process. By J. F. Stevens 29 Lantern Slides. How I Make. By H. J. Newton ... 70 Lantern Slides. How to Colour. By G. M. Hopkins 52 Lantern Slides in Summer 78 Lantern Slides of North Wales 39 Lantern Slides on Gelatine Plates 46 Lantern glides. Printing Out. By W. H. Shirley ... 38 Lantern Slides. Print Ont. By S. Herbert Fry 92, 110 Lantern Society 104 Lantern Stereoscope 98 Lantern Trade. State of the 95 Lever Key. New Folding 40 Lighthouse lUnminante. By W. P. Anderson ... 77 Magnesium for Lantern Slides. Mending Broken Slides Metol. By W. B. Bolton Mounting Lantern Slides. By James Ross Mounting Paste for Lantern Slides By A. L. Eidemiller 39 PAGE "N, & G." Hand Cameras 63 Neuhauss' Lantern ,34 Nydia Camera 116 Oil Lanterns — Translucent Screens. By James Lewis 115 Opaque Lantern Screens 85 Optical Lanterns. Ventilation of. By T. N. Arm- strong 27 Oxygen. Dilution of 25 53 65 112 Photo -micrography. By A. D. G. Shelley Photo-micrography. Oi-thochromatism Applied to ... Photo-micrography Simplified. By W. I. Chadwick . Photo-micrography. Use of Orthochromatic Plates in. ByT. F.Smith Photo -micrography with Artificial Light. By Prooelia Pompeii on the Lantern Screen , Projected Portraits. By Limelight 116 Regulator. Genesis of the. By R. R. Beard ... 51 Rural Technical Education and the Lantern. By Alfred Watkins 85 Scraps from My Note-book. By a Tourist 95 Search Light. By Raduint 99, 107 Shipping on the Screen 1-2 Silver Intensification. By W. B Bolton 114 Skies in Lantern Slides. By S. H. Fry 45 Slide Making by Reduction 40 Stereoscopic Negatives. How to take 87 Steward's New Optical Projection Lantern 72 Submarine Photography by Artificial Light 104 Tasmania. Lantern in 06 Transluoency of Imag'o in Lantern Slides. By W. B. Bolton 67 Transparencies and Enlargements without a Con- denser. By W. B. Bolton 82 Varnish for Collodion Lantern Slides 29 Varnish Useful for Negatives or Transparencies. By W. B. Bolton 43 World's Fair. Official Photographer at the 80 Zoopraxography on the Screen at Chicago 39 CONTRIBUTORS. PAGE ASDtESOK, W. P 77 Abmstbono, T. N 27 Baxir, O. B. 27, 34, 44, 50, 60, 67, 75, SI, 91, 95, 109, 113, 117 Bautbs, C. W 25 BuBD, K. R 51 BoLTon, W. B. 26, 43, 50, 59, 67, 74, 82, 90, 100, 106, lU Chadwick, W. I. 28, 112, 118 KlDKIILLXB, A. L 39 Frt.P. H 45,92,110 Faemeb, H. E. Hopkins, G, M. Ives, F. E. ... Jkhney, W. p. Lewis, James... Newton, H. J, Nhtt, H. S. ... Paeeott, F. W. peoceli.a Radiant PAGE ... 46 Ross, Jas ... 52 Shelley, A. D. G. ... ... 28 Shieiey, W. H. ... 77 Smith, T. F., F.R.M.S 107, 115 Stevens, J. F. 37,70 Stirling, B ... 55 Tourist. A ... 88 Woods, C. Ray .. 69 Watkins, A 99, 107 Wribbt, Lewis PAGE ... 38 ... 53 ... 93 ... 29 ... 8t ... 95 45, 76 ... 85 ... 58 r' THE BlUTISH JOURNAL OF PHOTOGRAPHY. No. 1705. Vol. XL.— JANUARY 6, 1893. SCULPTURESQUE PHOTOGRAl'HY— A NEW STYLE OF STATUARY PORTRAITURE. For many years an imitation of statuary has been maf/raphic Times. The following sentence from the second paragraph in his correction is quoted verbatim :" "Objircts at various distant planes appear in relief when seen at a C'^rtain angle, theoretical for our vision, one having for its base the distar.ce which separates the centre of the two eyes, about 2^ inches." The spelling of the word " centre " suggests that the sentence itself may be a o notation : but, how- ever it may be taken, it appears to be meaningless. Thee, to explain matters, he takes two woodcuts of stereoscopically different places, one the right way up and the other upside down, and calls them pictures seen by the right and left eyes. He then repeats the two engravings upside down, and calls them the pictures seen by left ami right lens. lie ends by stating that a stereoscope '• consists of the two halves of a bi-convex lens, which consequently give to the rays of light exactly the same direction : they are convergent.'' This is too delightful — rays the same direction, and convergent. Finally, he ought to Icnow that the idea that the lenses should be prismatic in their section for stereoscopic effect to be produced is long ago exploded. The best form of stereoscope is one in which whole lenses are employed and the view looked at through their axes. Fbke Lance. BREADTH. -VMONOsr all the terms imported into the vocabulary of tha photo- grapher from the artist none is being more frequently used at the present time than the term " breadth." That photographers should gradually appropriate the expressions of artists is not to be deplored. These terms have most of them been long in use, long before photography was dreamt of ; and the fact that they still survive may be taken as proof that they fultil their functions satisfactorily. These terms, somewhat meaningless in them- selves, have come to have a very definite meaning attached to them ; and, as the term " breadth " is frequently quoted in an erroneous way, it might be profitable to inquire into the precise meaning of the word. While it might be difficult to frame a hard-and-fast definition of the quality denominated breadth, it is not difficult to explain what it is. It is that quality which makes for simplicity ; it may apply to out- line or form, to light and shade, or to colour.' In an outline drawing whatever deviations break in upon the general direction of the line render the design mare complex, and therefore destroy breadth. Again, in light and shade, whatever deviations break in upon the general tone of a mass destroy its breadth. Tlie power or effect of a mass of colour depends entirely upon its being as far as possible unbroken. I do not enter Inby the question of how far this quality of breadth or simplicity is to be carried out ; manifestly it might be carried too far. I am only con- cerned with its identity. Now, to what extent can it be said that photographs have breadth ? If we narrow the meaning down to that quality which an artist puts into his work as deliberate design or intenf.ion, apart from Nature, I am ready to argue that they have none of ^his quality, notwith- standing the out-of-focuB dodge. On the other h^id, Lf you a tion be entirely confined to the former conditions, that is, wher» Nature herself is rather too complex for either artist or photOjBfraphtir to treat with succeas pictorially — where, indeed, Art can improve on Nature, bringing order out of disorder. Now, let us clearly understand what has to be done. First, in order that the outlines may be more evident and easily followed, deviationa from the general direction of the lines must be curtailed. By this means the eye follows with ease the simpler lines ; in other words, breadth is introduced. But photographs from Nature are not merely outline drawings — they have ligiit and shade, and breadth must be introduced here also. There is only one way of doing this, and that is by a process analogous to the former. All deviations from the general tone value of the masn must be curtailed. Just as nnity is power in social matters, so unity is power in pictorial matters, and by bringing a host of independent entities into subjection the design is simplified, and power correspond- ingly increased. Now, since the artist makes his picture ab initio, he can, of course, introduce breadth to any extent ; but how about the photographer 'i It has become a part of the advanced photographer's creed to put down want of breadth in a photograph to an over-abundance of detail. Accepting the objectionable and slipshod expression, it is not dirticult to show that there is no such thing as detail per te in any picture, that is, since everything in a picture is represented by out- line, light, and shade, "^^'hen an individual says there is too muck detail, he must only mean that both outline, and light, and shade are too complex for effect. It is now proposed to mend matters, by putting the picture, to some extent, out of focus ; and, first, whait effect will this have in simplifying outline ? It must be admitted that this will, to an infinitesimal degree, cur- tail deviations from the general direction of the lines ; but note that rt is at the expense of a hazy outline, which, in place of being mors easily followed by the eye, is still more difficult. Contrast this with what one sees in Nature. As objects recede from the eye the outline gets less and less intricate, but the //encrrt/ outline remains quite sharp, till at last the distant hills at the horizon, in place of having a " fuzzy " outline, stand out with razor-edged sharpness against the sky, and this, too, so long as there is a trace of them visible. When the artist would introduce breadth into his picture, h* simplifies the outline by sinking deviations from the general direction of the lines, not by making a fuzzy outline. In this he copies Nature, acts on her plan. I repeat that, in Nature, as the complexity of the outlines gets less and less by distance, so the general contour gets more and more definite ; but, bad as an out-of-focus picture is in outline, it is still worse as to its light and shade, for, since bj' no reasonable amount of racking out or in can tlie light and shade in any photograph be materially altered, by robbing the shadows of their detail their identity is lost, and they become meaningless patches of black. The same holds true of the lights, of course. In point of fact, detail, to use the word in its somewhat indefinite but ordinary sense, may be present in a high degree without inter- fering with the breadth of a picture at all, the only condition being that it be invisible from the distance necessary to command the com- position as a whole, in which case I admit its uselessness, of course. The distance to which one must retire in order to command the composition as a whole ought to determine the amount of so-called detail, for, while more of it may not, if judiciously handled, injure tthe breadth of the picture, it is at least so much labour lost if it is »ot visible from the standpoint proper to view the picture. In my opivna there is only one way of introducing breadth into a photograph-^ choose a subject having the desirable quality in itself. J. K. TCLLOCH, M.B. HOW TO MAKE PEN-AND-INK DRAWINCiS FOR PROCESS WORK. It will be remembered that in a recent number I explained as far sa could be done on paper, the process by which phototype illustrations are produced for tne Press, and the manner in which copies may be taken from photographs for this purpose. I will now endeavour to make clear in as precise a manner as possible the way in which the illustrations, technically known as " line " drawings, are produced. In the first place, it has often been said, even by men o^upyinx h'urh positions in the artistic world., that artbts are bora and not r THE BRITISH JOURNAL OF PHOTOGRAPHY. [January 6, 169.-3 made. To a certain extent this is correct, as no doubt in this pro- fession as in all otliers, the genius of the first water, the man who stands head and shoulders ahove all his contemporaries possesses an inborn talent for his work ; but it is possible for any one gifted with an ordinary amount of intelligence and capability for hard work to make a more or less skilful draughtsman. The path to success, how- ever, is by no means an easy one, continual study and labour being essential at every stage. In fact, it is impossible to become absolutely perfect. For the artist of feeling the whole world, animate and inanimate, affords interesting matter for thought and study ; and, as one of the chief means of obtaining a hearing in a profession already overcrowded with men struggling to get a foothold is to strike out an original line, it is necessary that the student should possess a keen eye for fresh subjects, and a vivid and retentive memory. Granted these conditions, the ambitious pupil may commence his studies. As the general reader is probably ignorant of even the first principles of an artist's method of work, it may not be uninteresting to state briefly some of the leading rules by which it is necessary that he should be guided. It is useless to commence drawing anything unless you have a clear and definite perception and grasp of your subject, and thoroughly understand its proportions and have deflned its limits. As in photography, so in a greater degree in draughtsmanship, a clear knowledge of the value of lights and shades, and a thorough acquaint- ance with " perspective " is of first importance, and it is here that a ^eat deal of hard work can be put in. Perhaps the best books for a beginner are Vere Fost«r'8, where the information is prepared and arranged in a most careful and commendable style. For landscape work, after the preliminary courses have been gone carefully through, the student should endeavour to advance by very easy stages — that is to say, to choose at first a subject which he can clearly grasp, where only one line of perspective is required, and where the background is not confused by a variety of objects. For instance, we will imagine that the scene chosen is a country lane, with a wall on one side and an open field on the other, with a farmhouse in the far distance, and a few trees within the line of eight, behind the walL It will be easier to attempt this in winter time, when the branches of the trees are quite bare, as the leaves very often prove extremely difficult to render naturally. The student should be careful to avoid standing in a too central position, and should endeavour to reproduce the shadows only, taking no notice whatever of the lights, as a much finer artistic effect is obtained by adopting that course. It is a mistake to suppose that the outUne itself of the subject should be drawn ; it is the shadows that should be filled in, and the real outline, as far as possible, merely reflected, or suggested by broken lines. By broken, I mean that the pen should be held very loosely, and should be guided so as to produce a wavy rather than an absolutely straight line, and it should be lifted altogether from the paper at intervals of from a quarter of an inch upwards, according to the size of the sketch. Straight and un- broken lines make a very crude and unnatural impression when the drawing is finished, and, in fact, a true picture could not be drawn if contmuous lines were used. Tints are got by varying the thick- ness of the lines. Thin and open lines must be drawn to depict the lighter shades, and as the shade deepens in intensity the lines should gradually increase in thickness and at the same time be placed closer together. Care should be taken to keep the lines from running into each other, and to make no attempt at crossing until the strokes are dry. If this is not carefully watched, the risk is incurred of losing part of the effect by the confusion and running of the lines, whereas, in crossing, it is necessary that each stroke should be quite separate and distinct. In order to train the eye to appreciate beauty and flow of hue, the beginner would do well to study the lines used by some of the best artists whose drawings are reproduced on wood, especially as regards the angle at which lines running transversely should be drawn, as nothing is so detrimental to a pen-and-ink sketch as to see the lines crossing at wide angles. In the case of rural scenes, and, in fact, in any kind of work, with the exception of architectural subjects, it is desir- able to avoid using photographs except as an after-guide for the sake of comparison; but with buildings it would save time and trouble if the student procured a photograph of the subject chosen. He would in this case be enabled to obtain a more strictly correct drawing than if he merely sketched it upon the spot, for in such work the lines are necessarily longer, straighter, and firmer than in figures or land- scapes. .\fter carefully copying with pencil every detail as an architect would do, he should proceed with pen and ink to suggest the shadows, as stated previously, rubbing out all lines in the high lights. This gives a very sketchy appearance to the drawing which the novice is apt to believe is easily produced, but it is, in realitv. only obtained by taking the greatest care in the first dra^ving oun' ' The pupil, by studying the works of Joseph Pennell, who is considered the best artist in pen and ink of the present day, will get a better idea of what I intend to convey in the foregoing. Without the aid of explanatory illustrations, it is exceedinglv diffi- cult to describe exactly the means which are u-^ed to obtain artistic effect and workmanlike appearance in a sketch ; but perhaps these few hints will help to a better understanding of artists' methods when their bearing is taken in conjunction with specimens of work such as I have described. Of course, much difference of opinion exists as to the degree of merit of different artists, but, in the main, it will be seen that they all work from the same basis and use the same means to obtain wliat, by virtue of their various methods of execution, gives to the eye an alto- gether different effect when completed. Now, with regard to figure drawing, it is worse than useless to attempt to copy photographs unless, perhaps, those taken by the stereoscopic process, which, when focussed in the special lens made for this purpose appear as they would viewed from the figures them- selves. In order to be able to sketch true tu the life, in addition to his lessons in pen and ink, an artist should carefully study the prin- ciples of physiology and anatomy, and endeavour to make a true delineation of every bone and muscle in the human body. The proper course to follow to gain this knowledge is to join what are known as the " Life " classes. Here the construction of the frame is first ex- plained by means of casts of different portions of the limbs and body, and the student is gradually led to the higher studies from the nude. In this connexion also, it may be said that perfection is never reached. The frame is made up of so many delicate and intricat* muscles and sinews that to trace, and faithfully copy, every one is the work of a lifetime. After finishing the English classes, many of the promising men are sent to Paris, where, as every one knows, art is supposed to have reached its topmost pinnacle. Germany and Italy also afford vast fields of knowledge for the artist who desires to become a true cosmo- poUtan in his profession. Of course in Italy the schools are mostly devoted to the teaching of painting, i s in thxt country one is able to obtain probably the finest scenery in the world. A. J. GotroH. PHOTOGRAPHY AT THE MUNICIPAL TECHNICAL SCHOOLS, MANCHESTER. .4.T the Municipal Technical Schools, Manchester, the optical lantern is extensively used by the various teachers, and the slide supply is an iinportant branch of the " preparation." Many, if not most, of the slides are necessarily made from drawings, diagrams, &c., in the various text-books, and it is to the reproduction of such illustrations that a special department has been created, which has been found an immense boon in many ways. There are two rooms occupied, one containing the apparatus for making negatives and for finishing the slides, the other as a dark room. The apparatus used is that invented by Professors Strode and Barr, and it is a marvel of compactness and efficiency, the illumination used being that obtained from two Argand gas burners. The plates used are " the Castle brand," the exposure varying from one minute to two. The whole arrangements are brought down to almost a mechanical operation, as scales are fitted at all points. For instance, we will sup- pose a diagram nine inches long is to be reduced to lantern-slide size, the book containing it is placed on the top of the box, the diagram being hung opposite the camera, or, if a loose diagram, it is pinned upon a board, which can be hung in situ without trouble. The camera stand is next pulled away until a pointer on bottom is at figure 9 on the tramway. The back of camera is also pulled out until a similar pointer is at 9 on the base of camera, a glance at a scale running up the side of it perhaps shows that the bottom line of diagram is eight inches from top, and that the top line of diagram is two inches from the top. These two added together total ten, so a small screw at the side is loosed, and the camera raised or lowered until a pointer on side is at ten. Then, on glancing at the ground-glass screen of camera, we shall find that the image is the right size, is in centre of plate, and is in good focus. Remove the focussing screen, insert the dark slide, and with lOo seconds exposure we shall obtain a cor- rectly-timed negative. In entering the dark room strangers always step in very gingerly, and ask if the floor is safe, because the room has been the' shaft of a lift ; this room is lighted from the top, being covered in with two thicknesses of orange fabric for lighting in the evening, or, in dull weather, a small incandescent lamp in an orange bag hangs con- vemently over the bench, and the current can be switched on without any trouble. A special hydroquinono developer is used, and is January 0, 1803] THE BUITlSIl JOLKNAL OF PHOTOOltAPHV. ;renerallv allowed to act whilst two more exposures are being made by which time, as a rule, the iiepitives are fully developed, ready for washiofif and fixinfir. After tixinp;, they are thoroughly wa«hed in an automntic appiratus, then pi.t on rack till dry ; when dry, the nega- tives are examined, and those needing the operation are intensified, bleaching with mercury, followed by ammonia, or by hypo, if only a little extra density is required. The slides are made upon Mawson's lantern plates, tlie exiwsure being made to the light of a gas-jet at a distance of nine inches, tlie developer being hydroquinone. \\'hen ordinary photographs are to be copied, about three times the exposure is necessary, the developer ufwd being pyro soda for the negatives, and hydroquinone for the slides. Slight over-exposure in the slides is corrected by immersion of the slide in a mixture of hypo and ferricyonide of potassium. The department is worked entirely by Miss Williams, and, although only of verv recent establishment, the slides produced are of a high class, and tlie quantity sufficient for tliis unique school. The present schools (three separate buildings) are shortly to be superseded by a magnificent pile of buildings, in which photography will be allotted a good position. The clas.«es on photography and photo-mechanical processes are quite new, but up to the present are well attended, and the pupils show some excellent work. The lectures are practical as well as technical, and treat of modern methods instead of, as is usually the case, obsolete or nearly useless ones. W. T. Wilkixso.v. A SUGGESTION FOR HEGULATING AWARDS AT COMPETITIVE PHOTOGRAPHIC EXHIBITIONS. Most will agree that the task of awarding medals and adjudicating upon the respective values of pictures sent to photographic exhibitions has hitherto been of a somewhat thankless and unsatisfactory nature. Why this is so is hard to define with any certainty, for those to whom the task is entrusted are invariably selected for their known discrimination and knowledge in matters of the kind. No matter who the Judges may be, there is always more or less grumbling at the results, and not always from the non-recipients of the awardsl I will now suggest what, perhaps, may be when more elaborated an improvement in the system of judging usually adopted. My idea is that there should be a kind of standardised opinion, to be settled by committee as to details, but constructed on the following lines. To make myself clear, I will sketch how the judging is frequently managed. The gentlemen appointed for this oiiice examine the photographs one by one, or ought to, and put down on a strip of paper a certain number of marks, as representing the value of the picture under their examination. The higher the number, the more favourable the opinion ; from one to ten is usually adopted. At the end of the examination the numbers given by each Judge are added together, and the photograph receiving the greatest number of marks is considered the prize picture. It will be seen that this system is defective, because each of the four or five censors may estimate the value of the picture from quite ;i different standpoint that can have little or no connexion with the other. One may appraise a picture for its artistic qualities, and anotlier for its manipulative excellencies, and others from standpoints in their own minds utterly distinct from the rest, with the result that good qualities of different kinds actually neutralise each other ; and tl\e whole ends in an unsatisfactory muddle, the Judges themselves being more or less surprised at the result, although it would seem no better plan could be adopted than the absolutely unbiassed opinion of capable men so obtained. My proposition is that, in the first place, definite qualities shall be adjudicated upon, and these classed under four heads :— 1. Artistic excellence — grouping, ligliting, posing, and form. 2. Manipulative excellence— brilliancv, delicacy, and freedom from defects of all kinds. 3. Colour and texture. 4. Mounting and framing. Printed lists should be provided as indicated in diagram. The first column containing the number of the pictures, and the following ones headed as above, with a division for remarks. Remarks. Suppose each Judge m supplied witii one of these printed lists. He will examine No. 1 picture, and place so many marks, accordin Pyrogallic acid in solution will, in cold weather, discolour far'<. quicker than when warmer, and this in spite of an increase of a pre- servative, such as nitric acid, sulphite of soda, &c. . Therefore, wJieu good work is required, care must be taken that the temperature of the solutions is not allowed to fall below 60° F. The dishes u^ed for development must also be warmed prior to use, as it will obviously be useless to pour warm developer into a cold dish, and then expect that .. the solution will warm the dish and retain sufficient heat to perform . its f unctiops properly. When a negative is developed in a warm solution, not only is it better, but it is also cleaner and freer from stain than it would be if developed in a cold solution. Present-day dry plates will bear a solution as warm as 80° without danger, hut 60° will be as high as ij necessary for the developer to be before pouring over the plate. A cold developer, as well as giving poor negatives and causing stains, also causes frilling and blisters. The blisters sometimes dry out without leaving marks, but frilling caused by cold solutions is far more difficult to deal with than is frilling caused by hot weather or by the useof a developercontainingan abnormalquantity of fixedl alkali. Cold weather also has a deleterious effect upon printing methods. The light, being weak, does not penetrate the denser portions of the negative, consequently the lighter half-tones are deficieht in detail. ' To some extent this may be remedied by extra depth of printing,' but not altogether, because it is generally "necessary to print somewhat deeper in dull weather in order to get" a bright print. For winter printing weaker negatives will always give better re- sults than very dense ones, but in tliis connexionit is necessary to observe that the full gradation is present. A negative, whether strong or thin, must be so, from the highest light to deepest shadow. An under-exposed negative is bad for either summer or winter. In washing paper previous to toning, water, with a temperature of at least 60° Fahr., should be used. After toningi the temperature is of little importance, but the toning solution should never he below 70° — that is, wliere good, brilliant tones are required. These remarks apply as much to gelatino-chloride papers (printing-out paper) as to albumenised paper; but, if the temperature of the solutions be too high, the gelatine papers are apt to friU and the image float off • the paper. They will withstand a temperature of 70° without danger, but not higher. A point of great importance in connexion with gelatine-ooated ' papers is this, they must be washed in warm water ((50° to 65°) before ' toning; it is quite useless to wash in cold water (below 40°), then tonein asolution about 70° ; the tones are poor, and thehalf-tones suffer. Gelatino-chloride prints, intended for enamelling, will be found to strip off the glass better if soaked in a solution of aluminium chloride for ten minutes, and washed afterwards ; in fact, all gelatino-chloride prints are better for this treatment, as the chloride has such a harden- ing effect upon the gelatine as to make it more brilliant, and make it practically insoluble. W. T. Wilkinson. COLOURLESS ALKALINE PYROGALLOL. As illustrating a lecture on oxygen or air, says Mr. Alexander Johnstone m the Chemical News, a strong solution of pyrogallic acid in KHO or NaHO is often exposed to the gas or the atmosphere to show its great power of absorbing free oxygen, and its instant change of colour when exposed to it. This experiment " tells better " if a clear, colmirle^s solu- tion of alkaline pyrogallol be shown to the class before exposure to oxygen. This can be done very easily and quickly. Into a rather deep test-glass, such as is ordinarily used iu lecture experiments, place some solid pjrogalUc acid, and then a little water, just enough to 'barely dis- solve it. Next put a small handful of sodium carbonate into a flask, and cover with HCl to drive the COo off. Ponr the CO., gas into the ghiss above the pyrogallol, and then add the KHO to the 'latter. The das.-, will see that the alkaline solution below the CO., remains colourless. To show the change caused by the presence of O, p'ass the latter from a tub.; into the lower stratum of the 00^ covering, or incline the glass so as to throw out the CO. aud admit the au:. The chantje will bo instantaneojs. Janiinry 0, l'0:l] THE BiJITISHHIOURXAL OF IMlOTOtmAPllY. 9 MEASUBEMENTS OF CLOUD HEIGHTS AND VELOCITIES. The Annals of llanurd College Ohservatoni contain a discusaion by H. H. Clayton of the cloud observations raado at Mr. A. L. Rotch's observatory at Bine Hill, Massachnsotts. The details ijiven may be of interest to those who Miakc clond photography a study. One of tlie most noticeable facta brought out by the measurements of cloud heights and velocities, which have been conducted with threat care, is the difference in height between the same clouds in summer and winter, the clouds, with few exceptions, being lowest in winter. Tlie bases of the oumulo- nimbas clouds, however, are generally lower in summer, while, at the fame time, their tops are higher than in winter. The heights of the different clouds were found to maintain an almost constant ratio to each other. The mean velocities recorded showed that the entire atmosphere moves twice as fast in winter as in summer. The mean velocity of the highest clouds in winter was about 100 miles an hour ; the extreme velocity amounted to 230 miles an hour, from which it appears that the upper currents are much more rapid over America than over Europe, which possibly explains the greater velocity of the storms in America. As regards the direction of cloud movement, the tables show that from the highest clouds to the earth's surface the prevailing wind is west ; about 4000 metres more than ninety per cent, of the observations show the clouds from some point between south-west and north-west inclu- five. In |the cirrus and the cumulus regions, and near the earth's surface, the prevailing direction is from a little north of west, but in the intermediate levels, from a little south of west, the excess of the southerly component in these regions being possibly due to the inlluenoe of cyclones. ♦ AMONG THE BEES WITH THE CAMERA. [Greenwich Photographic Society.] Kakly this summer I first made my acquaintance with the bees with the camera, though I had done a lot of photo-micrography of the anatomy of the bee, and tlie pictures I shall show are the] results of my various excursions to Orpington and Bromley, in company with Mr. Broughton Carr, editor of the British Bee Journal, to whom I am much indebted for the arrangements of the hives and various appliances that I have photo- graphed. A prosperous colony of bees at the beginning of the swarming season consist of a fertile queen, a few hundred drones, and from 30,000 to "lO.OOO workers ; the mother bee, or queen, as she is usually called, is a perfectly developed female, and deposits all the eggs from which the other bees are produced. These eggs are of two kind.s ; the one develops into drones, and the other, under ordinary treatment, produces worker-bees, which arc undeveloped females ; by.t the same eggs, under different treat- ment and care, produce perfect females, or queens. The queen usually lives from three to four years, and is distmguished from the other bees by her form, size, and colour, being longer, darker, and of more slender structure, with comparatively shorter wings than either the drone or wo.ker, as but one queen (except in rare circum- stances) is allowed in a hive at one time, young queens are only reared when a colony is deprived of a queen, is aoout to swarm, or if she becomes aged, or her fertility ceases. In from three to five days after birth she leaves the hive for fertilisation by the drone or male bee, which, when once accomplished, suffices for life, as ordinarily she never after- wards leaves the hive, except when accompanymg a first swarm. If her death occurs, or she from any cause becomes unproductive when there are ib-ones in the apiary, and young brood or eggs in the hive, the workers construct larger cells, callediiueen-cells, supplying the larva withabundance of rich focnl, and the eggs which would otherwise produce worker-bees are developed into queens. If the queen does no: deposit eggs in any of them, the bees will supply them with eggs, which they remove from worker-cells. If they are not able from any reason to become fertilised, ehc will only lay drone eggs. The queen has a curved sting, which she uses when contending with a rival ; she is capaljle of laying as many as from 2000 to 3000 eggs a day, and is in her prime the second season, After which her laying powers decrease. The drones ai-e more bulky than the queens, and are larger than^the •workers. They have no stings, lead an idle life, and, with the exception •of assisting to keep up the temperature of the hive, do no work for the support of the hive, but feed upon the produce of the workers. At the •end of summer, when their services are no longer required, food is with- held from them, and they aro turned out to perish. The workers, which are tho most diminutive in size, are too well known to need description. The slide shows the queen, drone, and worker ; it is a photograph of the insects set out so that the relative distinctions of form may be compared. Upon this bee devolves all the work of collecting and defending the stores, building comb, feeding drones, and feeding and protecting the queca and brood. They rule and regulate the whole economy of the hive, and perform all its offices, except those which have direct reference to the reproduction of the gpeciei. Daring the 8ummer months the workers do not live more than six to eight weeks, owing to tho hard work they have to perform, but worker-bees hatched in the autumn usually live through the winter, and commence the work of the hive in the spring. An egg deposited by a queen in a cell pre- pared by the workers hatches into a small grub in three days ; it is cherished and fed until the ninth day, when it becomes a nymph, and is sealed in its cell to emerge a perfect bee. Having taken up too much time in describing the three bees, I will pass on more quickly with the photo-micrographs of some of the parts of the bee. It will not be necessary to go into the detail of class, order, or family to which they belong, except to say they are of the order Hymen- optera, genus Apis, species Mellijica, this being indigenous to Great Britain. There are no less than eight distinct hairs on the bee. I am sorry that I have not a slide to show yon. The most important part of the bee is its head, which differs very much in form in the three bees. The tongue consists of no less than five parts. The centre is the tongue proper ; the two parts on either side form the cover, or sheath ; the two above form another cover, into which the whole is drawn when not in use. At the end of the tongue is what is called the spoon, circular and concave, with a row of pale clavate hairs along the edge, and short, hooked hairs on the inside. At the narrowest part of the tongue, just above the spoon, there is a fringe of guard-hairs. The eyes consist of a pair of large compound eyes and three simple eyes. In the slide of the compound eye we shall find the outer layer divided into a number of hexagonal facets, which are convex, and form the cornea. Between most of these facets are seen long, straight hairs, which act as protection to the eye similar to eye-lashes, and they are also sensory. The second and third segment of the thorax support the wings. The lower wing, along the upper edge, has a row of booklets, twenty-three in number, which, when the wings are extended, catch in the fold of the upper wing, and this gives to the consolidated combination of the two a greater surface and force in beating the air to accelerate its progress and carry "its body. The third legs of workers serve as gatherers and carriers of pollen. The upper joints are covered with long feathery hairs, the tibia or second parts, constructed for the conveyance of pollen and propolis, being framed externally like a little basket. It is smooth and hollowed, and the lateral edges are fringed with recurved hairs, which retain anything that may be placed in it. Along the lower extremity it has a row of stiff bristles, called the comb. The tirst leg, as shown, you will notice near the upper end, and on the inner side there is a deep curved incision , called the sinus, terminating in currycomb. Its function is to keep the antenniB clean and free from pollen. When the insect wishes to cleaui one of its anteanie it lays it within the comb, and the velum of the spine upon it ; the combined action of the comb and the velum removes anything that is upon it. The operation may be frequently observed, and it would be noticed that tlie antennie on the right side are cleaned by the device on the left leg, and the antenna: on the left by that of the right leg. A few words here on the breathing apparatus will not be out of place. If you look at the diagram, you will see that the air enters through the spiracles at the side of the abdomen into the tracheal tubes or air sacs ; by means of these trachea- air is carried to every part of the body. Each spiracle consists of two, opening one behind the other, the inner one being closed by a valve, and the outer one is i^rovided with short hairs along the edge of the opening to prevent dust and other impurities from entering. This slide (of the sting of the bee) shows the whole of this complex apparatus with the poison bag, consisting of the barbed lancets and the divided sheath and the palpi, which are covered with sensitive hairs, so that the bee can find a soft place to insert the sting. This slide shows the barb more highly magnified. The lancets have a fine cutting edge, and are provided along their outer edges with ten deep retorse barbs, down which the poison (lows. If the bee is not disturbed, after it has inserted its sting, it can by giving it a twisting motion with- draw it, but it generally leaves its sting behind, tearing away the whole apparatus and part of its abdomen. This shows the skin of the abdomen with its hairs and wax plates. The salivary gland would take too long to describe now. I will show the most interesting of my pictures — the outdoor work with the camera among the bees. This is a photograph of an old cottage apiary, and shows you how not to keep bees if yon want to keep them clean and healthy. ^Ye had a great deal of difficulty in getting this photograph, as there is so very much superstition among bee-keepers. They were afraid 10 THE BRITISH JOURNAL OF I'HOTOGRAPIiy. [January 6, 1800 something terrible would happen ; either the bees would all take flight, or the queen die, and they would get no honey ; but I believe, beyond a good row, nothing has happened. This shows a modern apiary, all of the newest, up-to-date hives, and is the property ot Mr. Broughton Carr, through whose kindness and help all the slides to be shown have been done. It stands with a southern aspect, with a high bank to shelter it from the north wind, and under some small trees of apple and plum. Here we have the bee-keeper tiering a hive. When the honey begins to flow, and the brood is well in hand, the bee-keeper puts on a tier of comb or sections for the bees to fill with honey. In these frames are put twenty-one sections, and when they are nearly completed, twenty-one more are put on, and the ones nearly full are lifted up and put on the top of the others, and it is possible to get as many as seventy sections filled with honey from one hive. To examine a hive it is necessary to quiet the bees, and the best means of doing so is to use a smoker. The hive cover is taken off, and the quilt just turned back at the corner when a little smoke is puffed in. This is bee dress with veil, which at times is very useful, as in hiving a swarm, changing the hives, and many other occasions. Having quieted the bees the cover can be removed, and a frame taken out to see how the brood is getting on, and that there is no foul brood or parasites about. Now, to look at the other side of this frame, one has to be very careful, or else the comb will drop out. It must not be turned over, but must be kept in a perpendicular position. Catching the queen. This frame ot comb had been taken out of the hive to see how the work was going on, and on looking over it we found the queen. There was a great uproar in the hive during the absence of her majesty, and, when the frame was replaced, it was curious to note the change of tone and hum of satisfaction that took place. Had she been absent a little longer, most likely all the bees would have been off. Taking a swarm under great difficulties. This swarm was very un- settled, half the bees were on one tree and the other half on another tree some ten yards apart. The day was intensely hot, a clear sky and burning sun, so that the bees would not make up their minds where to settle, and kept flying backwards and forwards from tree to tree ; at last they began to cluster on the top of an apple-tree ; so you will see the diflSculty one had to get this photograph. When they were ready, my friend got up into the tree and shook them off into the skep, lowered it half-way down into the tree, and soon all the bees had gone in. Now comes the process of hiving this swarm. A hive has been go ready, filled with foundation frames ; a large white cloth spread on a platform made up in front of the hive, on which the bees are to be shaken out. This skep was nearly full, and probably contained about 30,000 bees. With one jerk the bee-keeper shook all out. I never saw such a mass of moving insects. The photograph was taken the moment they were down, for in less than five minutes all had entered the hive, so anxious are they to get comfortably housed ; and we were anxious to see the queen enter, but in the mass we were not successful. The bees may be driven out of the skep, and the combs transferred into a movable-comb hive, or a skep may be made to swarm artificially. To drive bees, this should be done on a fine, warm day, when many of the bees are away. The skep has been removed to a quiet spot, and placed on an old tub. Before you remove the hive you blow a little smoke into it; the bees at once gorge themselves with honey, and after a few minutes you puff in a little more smoke, and remove the hive, invert an empty skep over the top, bringing the edges together at the point towards which the combs run, then prop up the front with two iron rods bent at right angles at either end ; you then commence patting the hive with your hands, hard enough to shake the combs ; after a few raps, the bees will begin to swarm out and go up into the empty »kep. In about ten minutes all the bees may be driven out ; then they may be transferred to other hives, or whatever you may wish to do with them. It was curious to see how the bee can be subdued and handled without being stung. After the bees had been driven into the skep, a table was brought out, covered with a white cloth, and the bees shaken out on it, when Mr. Carr took them up and threw them over his hands without one of them stinging him. It will be seen that to make bees harmless it is simply necessary to frighten them into gorging themselves with honey, when they may be handled with impunity. The hive having been brought back and placed on the table, with the bottom just propped up how quickly they made their way across to the hive, when a few crawled up the rods, and soon formed two beautiful columns of bees, which soon agam became a mass. Closing up all the front in this way, the whole of the bees soon got back into the hive. A large quantity of surplus honey is collected in sections. These are made of one long strip of wood, so cut that it will fold over into a square frame, about 4x4. In the middle is fixed what is known as a wax foundation, so that the bees, instead of making wax, find it here already for them. They have only to work it, that is, to pull out the wax from either side, and build up its cells; and, as it takes from thirteen to twenty pounds of honey to produce one pound of wax, it will be seen that the bee-keeper that uses comb foundation must have a great advantage over one who does not. These sections are sold at about 1». each, and an many as twenty-one sections are placed in the hive, one sees how very profitable bee-keeping may be made ; and in a good season three lots of these sections may be made. The large frames are filled in the samo way. Only pure wax should be used. It would take too long to go into the detail of all the work of the bee- keeper ; but, any one wishing either to study the natural history of the bee or the practical work of the bee-keeper, I would refer them to Mr. T. W. Cowan's two books, Tlie Hone;/ Her: it» Natural History, and The British Bee-keepers' (riiide-book. This paper is, perhaps, rather disjointed, but it was roughly put together, and illustrated by some forty-five lantern slides, many of which are not described here. T. E. Freshwater, F.R.M.S. THE USE OF PHOTOGRAPHY IN PHYSICAL EESEABCH. This is the title of a very interesting and instructive lecture delivered before the Physical Department of the Brooklyn Institute of Arts aud Sciences, December 13, by Professor Edward L. Nichols, of Cornell University. The lecturer began by stating that photography is now used in almost every branch of physical research ; that it is often used advantageously as a substitute for drawing when making observations. Professor Nichols projected upon the scieen a number of views, illustrating the exploration of the magnetic field, showing the lines of force, and of various pheno- mena which have heretofore been illustrated by drawings made by the hand of the observer. In some cases the hand-made drawings compare favourably with the photographs, while in others they appeared to be in correct. The lecturer spoke of the value of photography in making long- continued observations; also in making observations of phenomena developed instantaneously, as in the case of lightning flashes, electrical discharges, sound vibrations, Ac. He also showed upon the screen a plate illustrating difi'raotion fringes formed by a small triangular aperture in a piece of tinfoil, the figure being very intricate, and altogether dif ferent from what might have been expected. An interesting illustration was that of photographs of the manometrie flame, the flame for this purpose being produced by a concentric burner, the illuminating gas being supplied to the central orifice while the oxygen flowed tlirough the annular orifice. The photographic flames produced in this way were very bright, clear, and sharply defined, and, although drawings heretofore made compared favourably with the photographic record, they were not, of course, as accurate as the photographs. Interesting views of the electric arc were shown, with which the hand made drawings heretofore used compared very favourably. The photo- graphs, however, revealed some phenomena which had not been observed by the eye. Among these were the brilliant particles thrown off from the arc, also the superior actinic quality of the light given by the incan descent copper covering of the carbons. A photograph of an arc on an Iternating circuit showed a succession of light flashes, proving the inter mittent character of the arc when produced by an alternating current. Other peculiar features were shown, among them an illustration of the arc oscillating from one side of the carbon to the other. This the lecturer supposes to be due to the attraction and repulsion of the earth's mag- netism. He stated that the singing of the arc was clearly due to rapid intermissions, and that the pitch of the sound proceeding from the arc was what would be expected from the rate of the reversals of the current. An attempt has been made to produce a photographic record of the alternating current by means of a telephone having attached to its diaphragm a mirror, the incident beam being projected on the mirror, the reflected beam being received on a moving sensitive plate. The result showed that the fundamental vibration of the telephone diaphragm interfered with the production of a correct record. For this method was substituted one in which a stream of mercury carried the alternating current, the apparatus being so arranged as to allow the stream to pass between the poles of a magnet. The mercury was oscillated by the attraction and repulsion of the magnet, the movement corresponding exactly with the reversals of the current. The mercury stream was photographed through a slit located at the point of greatest amplitude of vibration, and the curve produced was the sinuous curve expected trom. an alternating current produced by a machine working normally. One of the most interesting illustrations of the evening was that ot sun spots taken by means ot the spectroscope. This method of investiga- tion appears to have shown conclusively that the fecula around the dark portion of the sun spot correspond with the flames projected frouj the sun. Janunry 6, 189;i] THE BRITISH JOUKNAL OF PHOTOGBAPnY. 11 THE PABA-AMIDOPHENOL AND A&UDOL DEVELOPERS. [Section uf Photograpliy of the Academy of Soieiioei, Chicago.] TiiESF. developers, although of recent date, are now articles of commerce. The former was, I believe, first introduced by Dr. Andresen, which, for brevity, we will refer to as " phenol ; " the " amidol," by J. Hauff. Each of these developers is considered by many whose opinions ace entitled to great weight to excel all other developers. I have used the " phenol " for bromide-paper tr.'xnsparencies, and even half-tone negatives for photo-engraving, with yood results. I used generally substantially the following formula: — Sulphite of soda crystals, C. P. 2 ounces 4 drachms. Distilled water 12 „ 4 ,, Phenol 2 „ One grain of bromide of potassinm may be used to each ounce of developer. Dissolve the sulphite in the water while boiling, and, when dissolved, put the phenol in before it cools. I have used this developer thus com- pounded five months after it has been made without any apparent depre- ciation of strength or utility. For use, take one ounce of this stock solution, and add from four to six ounces of water with about one grain of bromide to each ounce of developer. I found upon using this identical formula, except that the developer was mixed with cold water, that it was an utter failure, hence the im- portance of using boiling water. In cold weather, unless this developer is kept at a high temperature, a copious amount of crystals will be formed on the bottom of the bottle. These cryatals will consist mainly of the para-amidophenol. , This 1 consider an excellent all-round developer. It may be used for any dry plates that have come under ray notice, isochromatic, ortho- chromatic, or otherwise, for making positives or negatives by contact, and for making negatives in the camera, for general portrait work, or behind a line screen for half-tone photo-engraving. It makes a nega- tive almost, if not quite, equal to the old wet plate. It allows great lati- tude in development, and should be very fully developed to allow for the density which it will lose in the fixing bath. It makes a fine-grained negative, but not as fine as the amidol. It does not require the same .skill and care to work it as the amidol, and may be used for many purposes for which that developer is useless. l<\om eight to ten plates may be developed with a solution of this developer. 1 first used the formula sent out with the amidol as follows : — Amidol 80 grains. Sulphite of soda crystals, C. P 800 „ Distilled water 8 ounces. Then took one ounce of this stock solution, and added from four to five ounces of water, with a plentiful supply of bromide of potassium. With proper exposure the image does not appear with undue haste, but after making its appearance it proceeds to complete development with great rapidity, but will not be injured by remaining in the developing solution for a short time. I found by adding seven ounces or more of water to the ounce of stock solution that the negative or positive developed in it would be covered with a surface fog or veil so as to make it entirely oseless. The above formula I will designate as No. 1. It was made four weeks ago, and the developer is but slightly discoloured, and works as well as it did the day it was mixed. On yesterday morning I made a developer which I will call No. 2, precisely like No. 1, except that it contained forty grains of amidol instead of eighty. By examining the bottle, which I have here, it will be seen that the solution is clear, which is undoubtedly owing to the great amount of sulphite of soda it contains. At the same time I made developer No. 3, precisely like No. 1, except that it contains 400 grains of sulphite of soda instead of 800, and, after mixing the deve- loper, it was boiled all together, the sulphite having been first dissolved in boiling water. The wine colour of the developer may be in part attributed to the small amount of sulphite of soda, and in part to the boiling of the solution after the amidol had been added. I would not recommend the boiling of the solution after the amidol has been added. It tends to discolour the negative or positive as well as the solution, which will be seen upon an examination of the bottle which I have here. I then made developer No. 4, precisely the same as No. 1, except that it contains 400 grains of sulphite of soda instead of 800, and the amidol was added after the solution containing the .sulphite had become cold. It will be observed that the solution is slightly discoloured, which is probably owing to the small amount of sulphite it contains. In all of these four developing solutions, the sulphite of soda was dis- solved in boiling water, as it should be in all cases, and the amidol should he put in when cold. The solution No. 1, according to the formula which accompanies the amidol, as will be seen by six positives which I have here, works well when used with plenty of bromide of potassium. The formula No. 2, reducing the amidol from eighty to forty grain.';, U, for some purposes, an improvement upon the original formula No. 1. The formula No. 3, reducing the sulphite of soda from 800 to 400 grains, and boiling the developer when mixed, cannot be recommended. The same may be said of formula No. 4. In two cases, after exposure, I gave the plates a bath for three minutes in a ten per cent, solution of bromide of potassium, and then developed them while wet. It will be seen, by an examination of these two posi- tives, that the bromide bath improved their density. It did not materially prolong the development. Amidol is the cleanest working of all the developers, and gives the finest-grained positives of any, and, in my opinion, cannot be excelled for making positives ; but I have serious doubts whether it will ever come into general use for negatives in the studio of the practical photographer. The plate developed with amidol loses no density in fixing. The colour is black and white like a wet plate ; but, while the black is fine in colour, it is not always opaque enough to make a good printer. Under certain circumstances, this is the worst of all developers to fog a plate. Amidol loses its active working strength when it has developed three or four plates, and should then be thrown away. I used in making these experiments, Carbutt's " A" Sen. No. 10, and Cramer's transparency plates. Sen. No. 12. My experiments vfith Car- butt's orthochromatio and Cramer's isochromatic plates with amidol were not successful. I regard a very free use of bromide as indispensable to the successful working of the amidol developer. It not only keeps it within due bounds, but prevents surface fog, and adds to the clearness, brilliancy, and beauty of the negatives or positives, J. B. BBinwEU* PHOTOGBAPHY OF THE LIGHT WAVES OF THE SMALLEST W.AVE-LENGTHS. At the meeting of the Mathematiaal and Natural Science Section of the Imperial Academy of Sciences of Vienna on November 10, Professor V. von Lange presented the following communication from Herr Victor Schumann, of Leipzic : — "The photographic energy of the ultra- violet rays on collodion and gelatine plates decreases strikingly at the wave-length 200 ufi, and falls off to a similar extent towards the more refrangible side. The cause of this decline in energy lies in the fact which I have established spectro- graphically; (1) in the impermeability to light of the collodion and gelatine, in which the sensitive ingredient of the coating of the plate, i.e., the silver haloid, is embedded, and (2) in the impermeability of the air which the rays have to traverse on their way to the plate. If we remove these two absorbents, the silver haloid shows itself many times more sen- sitive for the rays beyond 200 /j;i than it was in presence of the collodion and gelatine, and the photographic efficacy extends far beyond the pre- vious limit of the ultra-violet light (wave-length 185-2 fift). The produc- tion of a film of pure silver haloid on the plate offers great difficulties. A method for this purpose was hitherto not known. After numerous experiments I found a process by which I have now for two years pre- pared all the plates which I have required for observing the rays beyond the wave- length 185-2 fift. The air could only be removed from the rays by exhausting the spectrograph. In this manner I have hitherto been able to follow about twenty different spectra far beyond 185-2 ^/j. All of them develop here an unexpected wealth of rays, but none to so high a degree as the hydrogen light of the Oeissler tube. I estimate the number of the hydrogen lines, which I have isolated at 600, and the shortest of their wave-lengths at 100 /ifi. I have not as yet effected the measurements, for which, however, I have already made preparations." For illustration the speaker exhibited a tableau composed of Herr V. Schumann's original plates, showing the portion of the ultra-violet hydrogen spectrum first photographed by the latter. A KODAK GATHERING AND PBESENTATION. Bloomsbury Hall was, on Thursday last week, filled to overflowing by the employes of the Eastman Company both in London and Harrow, from which latter place a special train had been chartered to convey to London the numerous people there employed in the Company's factories. Their Paris and Nice branches were also represented, the former by the Manager and Manageress, and the latter by choice bouquets of flowers sent in profusion for the adornment of the room and the ladies who were present, for, in addition to the Chairman and some of the Directors of the Company, there were a few invited guests and friends. The occasion was ostensibly a musical and dramatic entertainment, but it was in reality an occasion for the employes to signify their appre- ciation of Mr. W. H. Walker's management and kindly feeling towards them by presenting him and Mrs. Walker with a tangible recognition of their esteem. It has for some time been known that this gentleman's health was giving way under the strain which he has undergone since 1885 in the establishing of the large business which now crowns his labours, and it was found that a long furlough from the active duties of the general 12 THE BRITISH JOURNAL OF PHOTOGRAPHY. [January C, 189:: managership was absolutely neoeaaary to recruit his health. His retire- ment from this post at the cloae of the year was seized upon as a fitting time to present him with a testimonial. It is creditable to the Company that the musical and dramatic pro- gramme was ably supplied by its own officials, in which the Harrow Kodak Glee Club came well to the front. At the termination of the first selection of music, Mr. Archibald Rider, the Secretary of the Company, said he had been asked by his colleagues to act as their mouthpiece to-night in connexion with that part of their proceedings to which they had now arrived, and to which they had all been looking forward with the greatest possible interest for some con- siderable time ; and it afforded him the more pleasure to do so in that it gave him the opportunity of publicly testifyina his own personal and warmest thanks for the many kindnesses he had experienced at the hands of Mr. and Mrs. Walker. They were met here to night to do the greatest honour they could to Mr. and Mrs. Walker, and to present to them a token of their love, respect, and admiration for their many endearing qualities. As soon as he learned that Mr. Walker had definitely decided to retire from the active management of this Company, it occurred to him that the occasion was the one opportunity they had for some time been looking out for of expressing in a tangible form that regard and esteem held by all for their chief and Mrs. Walker. The idea, when broached to his fellow-workers, was received with the greatest acclamation and enthusiasm. Everybody wished to go one better than his neighbour; but it would be invidious for him to mention individuals where all have worked with such a will to make a success of this movement. Paris, represented by Mr. De Bedts and Mile. Leonardon, Nice, Harrow, represented by about 120, and Oxford-street turned out to a man, were unanimous in their regret at the loss of such a chief, and in their love for and admiration of his great abilities and attractiveness of character. They all knew that the result of Mr. Walker's experiments and inves- tigations in the art, in conjunction with Mr. Eastman, had been the greatest revolution in photography that has occurred for many years ; and he felt sure that, when the future history of photography came to be written, Mr. Walker would of necessity occupy a very high position in the ranks of those to whom photographers are mostly indebted for their fascinating and lovely art. His and Sir. Eastman's invention of films and methods of using them alone has made photography a recreation, a pleasure, a delight, and last, and most important of all, for without it we could not enjoy the others, a health-giver to thousands. They were all well aware that our leading physicians now prescribe a Kodak to their patients, especially to those suffering from idleness, and the cure has been pronounced most efficacious. Therefore they would agree with him that, without any lack of modesty, Mr. Walker might, with far more justice than many who lay claim to it, pose as a philan- thropist. But there are other reasons, which for the present more directly concern us, why he should claim our greatest possible love and esteem. He did not think it would be here out of place to briefly detail Mr. Walker's connexion with the business in this country. As most of us are aware, Mr. Walker came here early in the year 1885 — like all good Americans, for a few months only, which from force of circumatanoes invariably turn into years — with the intention of making known to the photographic public of Europe the result of his and Mr. Eastman's dis- coveries. This 1m did through the medium of the Inventions Exhibition, then being held in London. The Photographic Committee of this Exhibition were so struck by the bold departure and possibilities of these inventions that, although they had already made up their minds in regard to the award for the greatest invention of the year in connexion with photography, they unanimously accorded the medal to the Company represented by Mr. Walker. Now, that was a very striking and encouraging success — so encouraging that Mr. W. immediately opened an office at 13, Soho-square. It was then the speaker's great good fortune to join him before even the fittings were complete, and he could picture him now as he then first saw him. He was sitting in a chair very much tilted back, with a cigar in his mouth, his feet on the table, superintending the fitting up of the office and endeavouring to instil into the workmen some of his own great energy. He soon made a host of friends, and of necessity — being so successful a few enemies; but they have, with hardly an exception, come to value liis great abilities and fine character, and are now numbered among his warmest friends. The business grew rapidly and continuously, and with it the staff and oilRoes. From one office and a dark room we blossomed to two rooms and a dark room. Then were annexed two attics for storing purposes, but at that point the capabilities as an office of 13, Soho-square were exhausted. Although the business had developed so rapidly, and was so highly successful— so successful that most men would have rested on theii laurels— Mr. Walker, with characteristic foresight, saw that, it the business was to be that great success he always intended it to be, a larger and retail establishment must be opened. So, with great energy and determination, and in the face of almost insuperable obstacles, he finally obtained the premises at 115, Oxford-street we now occupy. This was at ♦h? end of the year 1887. " The wisdom of this policy was immediately, and in a startling manner, shown by the tremendous increase iu the business. In 1889 we developed from a branch to a tree, and tools firm root in our own soil as the East man Photographic Materials Company, limited. From this point we are all familiar with tlie steady growtli of the Company and its interests. Again and again have we outgrown our clothes and required new ones. 1. The factory at Harrow was built and started, entailing such an enormous amount of work on Mr. Walker as would have appalled most, men. 2. Then he inaugurated a branch at Paris. 3. From that one at Nice. And lastly, we at 115 have overflowed into 117, Oxford-street. All this has been the work of one man. "Ladies and gentlemen" (continued Mr. Rider), "there are now employed by this Company over two hundred persons, all of whom are indebted to Mr. Walker's intellect, energy, and business capacity for their present positions, in most oases for their very livelihood. " But, as if that were not sufficient to command our grateful love, he binds us to him with the strongest chains by the kindness and considera- tion he has always shown to us all. Nobody, however humble his position, has received anything but the greatest possible courtesy and consideration. It matters not our position, we are all listened to with unfailing courtesy and patience, and he has always been most just in his treatment of us. " These are but very few of the many reasons we have lor thanking, him. Time will not peimit me to mention everything he has done for us, but I am certain that, whatever I have left unaaid, Mr. Walker will understand that he has our warmest aiJection, and that, wherever he goes- when he leaves us, he will carry with him our beat and heartfelt wishes for a long and pleasant life. I am sure that I am but echoing the senti- ments of all when I say that I feel the greatest pain at Mr. Walker's retirement ; but, in view of the incalculable benefits he has conferred on all of us, it would be most ungracious to begrudge him the rest he needs and has so well earned. There is, you will be rejoiced to hear, a bright speck in our present somewhat clouded horizon, inasmuch as Mr. Walker still remains on their Board of Directors ; and, knowing what I do of him, I feel sure that he will not cease from all active connexion with the Company, and, doubtless, we shall still often see him among us. I wish— and I know you are all with me — that I could say more, but perhaps Mr. Walker himself may think this a fitting occasion to raise our hopes. "I fear that Mr. Walker's qualities have caused me to neglect somewhat the claims Mrs. Walker has on us. Those who have enjoyed, as I have had the great pleasure, Mrs. Walker's friendship know how much she has at heart the welfare of everybody in the Com- pany's service. She has done for a number of us considerably more than we know of, and I know personally of several instances where her influ- ence on —and, failing that, scolding of — Mr. Walker has given more than one of us another chance. Why, if it were not for her sending Mr. Walker to us in extra good liumour some mornings, where would some of us be now ? The quality of mercy has been strained very considerably with some of us, and might have been broken quite but for Mrs. Walker's kindly intercession." Turning to Mr. and Mrs. Walker, he said, " It is my pleasing duty, on behalf of the employes of the Eastman Company, to present to you this small token of our great respect, regard, and admiration. In your retirement you carry with you our deep regret at the parting, and our heartfelt desire that you and Mrs. Walker will be spared many years in which to enjoy your well-deserved rest and new life." Amid great applause the curtain was raised, and displayed to view a, larg3 and massive silver salver with a suitable inscription engraved on it, together with a silver-mounted album, containing groups embracing every individual in the Co.-3ipany'3 employment both in this country and on the Continent. Mr. Walker, in acknowledging, on behalf of himself and Mrs. Walker, the handsome testimonial, expressed his extreme gratification at the spirit by which it had been prompted. He had always had the greatest faith iu the idea which he, assisted by Mr. George Eastman^ had endeavoured to carry into practical effect, and he could not but feel proud at the result of their labours as evidenced by the large numbers of those employed by the Company then before him. In future, although they would not see so much of him as they had done, he would always be among them in spirit, and would cherish the remembrance of the geniality of his inter- course with them and especially of that happy meeting. He concluded by formally introducing Mr. Dickman, his successor in the managerial chair. The meeting broke up at eleven o'clock. (©ur BTJitorial STatJlf- Since describing the Hemery's Medallion Group System of portraiture in our number of last week, we have been placed' in a position to illus- trate what we then said with two blocks, which show the nature of the invention better than could be given by a verbal description. In one the number of figures is four, in another, eight, but there is reall^' Januaiy 0, 189a] THE BRITISH JOURNAL OF PHOTOGRAPHY. 13 11(1 limit to either the number capable of being- printed on a card or iheir arranp-ftncnt -:■ '•' . \- w« havo pii'vunislj' said, Messrs. Marion & Co. are the agents for this useful novelty, which affords the means of presenting the whole of the members of a family on one card. " Nasik-it." This useful invention of Mr. A. (Jray, 44, Snow-hill, E.C., affords a means for printing the names and subjects on the negatives in a really neat style. Previous to its introduction, the lettering of nega- tives was a laborious proceeding, and few of those who attempted it achieved anything like success, but since "Name-it" came on the etage, the operation has become one of extreme .simplicity. It con- sists of a small box, having compartments for types of letters alpha- betically arranged, there being enough of each to serve in the compo- sition of a longer title than is ever likely to be required in the naming of a negative. There are also figures, spaces, an inking roller, and the other things which go to the making up of a complete printing outfit, as shown in the cut. " Name-it " has been subjected to considerable improvement since it was first introduced, resulting in the ability to print a clear, sharp title on the negative. For the purpose for which " Name-it '' has been introduced we can strongly recommend it. The Year-book of Piwtography, edited by T. C. Hepworth, F.C.S. (London : Alexander & Shepbeard), comes to us this year printed in large type^n this respect like the American annuals. In the " Guides to Practice," Captain Abney leads off with a seasonable article on " Winter Photography." Mr. Bothamley follows with " Lantern Teachings,'' and he, in turn, is followed by others of good reputation. The Editor's article on " Gas Cylinders in Transit " will prove useful to those who have to carry large cylinders with them for lecturing purposes. There are two full-page collotype illustrations, by Waterlow & Sons, and a pon-and-ink reproduction of a photograph, together with much that is useful reading matter in the shape of hints by the Editor. The Bbitish Jouhnal Photogiiaphic Almanac, 1893. HtUte• , ■ Mr. W. E. Debesham suggested looking through the picture, and judging the relation which the inten.sity of the deposit bore to the intensity of the negative. , , ,r ti_ ^ • i. The Chairman remarked that Mr. Cowan, Mr. Ashman, and Mr. Prestwich had invented special frames for the purpose. An actinometer could also be «sed. , Mr. J. S. Teape remarked that there was always some uncertainty as to tiie amount of the deposit that would fix out. POETRATTrRE BY ELECTRIC LiGHT. Mr. A. Haddon exhibited a negative (being the portrait of a lady) which he had that afternoon taken with the electric light. The light was not more than 1000 candle power. In order to use as much as possible of the arc, it was placed in about the focus of a concave reflector of about two feet in diameter. In front of the light was placed a screen, covered with tliin tissue paper, a large sheet of tissue paper being placed on the shadow side. He used a rapid rectilinear len.s, working .at /-ll, and gave an exposure of ten seconds. The screen was placed at about a foot from the light, and six from the sitter. The lighting of the negative was thought excellent. Curvilinear Distortion with Single Lenses. The following question from the box was read: "What determines the OTirvilincar distortion of a single lens, and how may it be modified ?" Mr. Debenham stated that it was determined by the position of the dia- phragm, and might be modified by altering it, while it might be entirely got rid of by making the lens itself the diaphragm. The diaphragm causes certain parts of the lens to select certain parts of the pictuie. Mr. Debenham illus- trated his remarks by diagrams on the blackboard. Impure Oxygen. Mr. Haddon alluded to a recently published letter of Mr. T. C. Hepworth, in which it was stated that commercial oxygen was sometimes contaminated to the extent of forty-five per cent, of nitrogen, and said that, as there were many lanternists among the members of the Association, it might be useful to them to know how to be able to test a sample of oxygen for purity. He promised to demonstrate the test at a future meeting. Mr. Grundy (of the Royal Naval College) had recently found that a sample of oxygen contained forty-five per cent, of nitrogen, while another of a special make only contained about eight per cent. In no case had the percentage been so low as five per cent. Other samples had contained up to fifteen per cent, of inert gas. Removing the Developed Image. A question having been asked as to the best method of removing the developed image of an unfixed plate, Mr. Thomas Bedding suggested either chlorising the image and dissolving it off with ammonia, or immersing the plate in a solution of tannin, to harden the film, and then dissolving out the image with nitric acid, 1 : 5. The meeting then adjourned. Croydon Camera Club.— A discussion on The Best Priniing Process to take lip was opened by the President at the meeting on January 2 in favour of bromide jiaper. In the course of his remarks, he emphasised that the lack of recognition which the said process has hitherto received is mainly due to the small proportion of men in the front rank who work it, and also that a very small proportion of those who take it up acquire the requisite experience and skill in order to turn out prints of the highest attainable quafitj-. In the resulting discussion various processes were advocated by Messrs. Oakley, Packham, Letts, Sampson. Garden, White, Hirst, and Neeves, most of whom showed large collections of prints in illustration of their contentiono. Mr. A. R. Dresser also sent a number of bromides developed with amidol, to show that the process in question can be made to yield very satisfactory results. At the termination of .%n animated debate a vote was taken, with the result that platinotype and gelatino-chloride tied for first place, and broniide was second. West Kent Amateur Fbotograplilc Society.— December 29, 1892.— ITie President (Mr. Andrew Pringle) gave a demon.stration of the Theory and Practice of Makini/ Oelalino- bromide JSmulsion. Having described the process in general terms, and explained the lines on which the operations are jierformed, he proceeded to make an emulsion, first with soluble bromide and silver nitrate, and then with ammonio-nitrate, explaining the advantages and ilisadvantages, in his opinion, of each process. A description was next given of various methods. Finally, a plate was coated, the speaker stating that, in his opinion, very few commercial plates were coated thickly cnougli, but that, •in these days of keen competition among manufacturers, economy must be observed somewhere. Dorset Amateur Photographic Association.— The annual meeting was held at Dorchester, on Monday, January 2. The outgoing oflicers were re-elected VIZ., President: Rev. W. Miles Barnes.— Pom mi«e« .■ Rev. E. J. Pope' Meiisrs. D'Aeth and Skene.— i/on. Secretary and Treasurer : Rev. T. Perkins! The Treasurer reported a good balance in his hands. The quarteriy prizes given for the best prints contributed to the albums circulated during the pa.^t year were awarded to Rev. T. Perkins, Mr. Skene, Miss Skiviow, and Mrs. Perkins. A special prize for a single print, given by Mr. Skene, fell to Mr. D'Aeth, and the prize for the best set of six lantern slides shown at the meeting was awarded to Mrs. Perkins. RECENTLY ELECTED OFFICERS OF SOCIETIES (Received too late /or the Almanac). Accrington and District Camera Club. — Established 1892. Meetings, first Monday in each month. President: Dr. Clayton. — Vice-Presidents: Joseph Barnes, — Cheney, Dr. Geddig, Rev. J. R. Rendell, — Stanley. — Hon. Treasurer: John Hanson. Hon. Secretary: Isaac Hanson, Rothwell Heights, near Accrington. Auckland Photographic Club. — Established 1889. Meetings, second and fourth Thursday in each month. Annual Meeting, second Thursday in October. Rooms, Australian Mutual Provident Society's buildings. President: Dr. J. Logan Campbell. — Vice-Presidents : Josiah M.irtin, J. R. Hanna. — Committee: A. J. Hunter, W. C. Fraser, W. G. Churchward, G. M. Maingay. — Treasurer R. Mason, Gas Company's Office. — Secretary: G. R. Boulton, Bank, New South Wales. Birkenhead Photographic Association. — President: W. H. Hunt, D.Mus., honioJi.— Vice-Pre.iideiU: C. B. Reader. — Council: G. Latimer, G. E.Thomp- son, H. B. Millar, W. T. Briggs, G. A. Camithers, W. A. Brown, C. Male, Thomas Mansell, J. H. Walch. — Lilyrarian: 3. A. Forrest. — Lanternist: F.N, Eaton. — Auditors: A. Bradbury, H. S. Nicklin. — Treasurer: A. F. Edwards. — Hon. Secretary: F. Hope-Jones, Prenton, Birkenhead. Brighton Natural History Society (Photographic Section). — Esta- blished 1892. Chairman: D. E. Caush, L.D.S. — Committee: A. H. C. Corder, J. Hunter Graham, G. Foxall, W. Mitchell, J. P. S. Slingsby-Roberts.— //o/i. Secretary : Walter Harrison. Bristol Camera Society.— Meetings, second and fourth Thursday in each month at 10, St. Augustine's-parade. President: C. Bryant. — Council: J. H. Brock, W. T. CIrank, H. J. B. Davies, M. E. Dunscoimbe, G. A. Evaus, E. Jakeway.s. — Hon. Treasurer: G. L. Wood. — Hon. Secretaries: M. W. Duns- combe, H. G. Tasker. California Camera Club. — Regular Monthly Meetings, first Tuesday after first day of month. Club Talks every Wednesday night. Illustrateri Lectures at Metropolitan Temple monthly. Address of Club Rooms, 819, Market-street, San Francisco, California. President: H. B. Hosmer. — First Vice-President: H. C. Tibbitts. — Second Vice-President: F. E. Smith.— Litrrarian: H. C. Owens. — Treasurer: George W. Reed. — Secretary: James W. DulTy. — Corresponding Secretary : Charles Albert Adams. Devon and Cornwall Camera Club.— Established 1889. Meetings, or alternate Mondays at eight p.m. Pl.ace of meeting. The Athenreum, Plymouth. Annual Meeting in September. President: Lieut.-Colonel R. Barringtor Baker. — Vice-Presidents: R. Burnard, W. Gage Tweedy. — Council: D. Aldridge, A. A. Camell, J. S. Hawker, Miss E. Keen, E. H. Micklewood, D. Roy, Colonel Stewart, R.E. , Captain Waye, R. N. — Treasurer : C. Russel Rendle. — Secretary : R. Hansford Worth, C.E., 42, George-street, Plymouth. Llandudno Camera Club and Lahtern Society. — President: The Right Hon. Lord VioitYa.^Vice-PTesidenls : Rev. John Morgan, B.A. (Rector o Llandudno) and Mr. W. A. Whiston. — Cmnmitlee : W. D. Henderson, Hughe- Jones, W. Owen, Waterson. — Hon. Secretaries and Hon. Treasurers : A. Campbell Paradwys, A. H. Hughes, Rochester House, Llandudno. Photographic Society of India. — Resuscitated in 1885 from the Photo graphic Society^of Bengal. President: The Hon. Sir.Conier Petheram, Q.C.- Vice-Presidents : J. G. Apcar and J. S. Gladstone. — Committee : Colone Rogers, R.E., P. Donaldson, N. Giannacopnio, B. A. Samuells, B.A., C.S. J. H. Lane, W. H. Jobbins, A. Tocher. T. H.IWilson, E. M. Showers.- Treasurer : George Ewing. — Secretary: T. A. Pope, Photographic Society o India, Asiatic Society's Buildings, Park-street, Calcutta. Queensland Amateur Photographic Society.— Founded 1888. Meeting held on first Friday in each month at the Builders' and Contractors' Exchange Courier-buildings, Queen-street, Brisbane. President: Dr. J. Thomson.- Vice-Presidents : J. W. Sutton, D. T. Lyons, F. R. Ua.W.—Cmnmiltee : Dr. J Wheeler, T. W. Bertinshaw, G. R. nohao-a.— Librarian : E. H, Alder.-, Treasurer: J. J. Campbell.— &cretar!^; A. R. L. Wright, Telegraph-chambers Queen-street, Brisbane. Richmond (Va.) Camera Clcb.— Established 1890. President: E. F. C V)is.v\s.— Vice-President : R. A. Lancaster, I'nn. — Kxecutive : E. F. C. Davis R. A. Lancaster, jun.. Dr. Phil Tayler, R. B, Blankenship, C. D. Hobliston. Secretary and Treasurer: C. D. Hobliston, 628 and 630, E Main-street Richmond, Virginia. Tasmanun Photographic, Science and Art Association. Hobart.- Established 1887. Meetings second Friday in each month, at Royal Society'' Museum. Patron : His Excellency Sir Robert G. C. Hamilton. — Via- Patrons: His Honour Sir Lambert Dobson, Hon. Dr. Agnevi.— President William Lovett. — Committee .■ Curzon Allport, Russell Young, A. Morton A. L. Butler, H. Downing, R. Shepperd, E. Robinson, E. Scott, D. Allport W. K. Morris, R. McGufHe, E. R. Ash, and H. J. MMc'klmA.— Treasurer F. J. Paterson. —Secretary : Nat. Oldham, Claremont, Hobart. Toronto Camera Club.— Club Rooms and Studio, Second Floor, comer o Yonge and Gerrard-streets. President : K Havelock Vf nhh.— First Vice President: A. W. Groil— Second Vjcc-Fresichnt : W. II. Uo^s.—Committet Hugh Neilson, N. A. Powell, M.D., Professor W. H. Ellis, M.D., J. G Ramsey, George H. Gooderham, G. To-miS&nA.— Treasurer : R. G. Muntz.- Secretary : Ernest M. Lake. January (i, 1803] THE BUITISH JOUIINAL OF PIIOTOGRAPIIY. 1-5 ViCTORTA Cameha Club.— Established 1887. Meetings first Monday in each moiitli. Presiilfnt: Hon. F. S. Dobson, Uj.M. — Vice-Prntident : A. M. HeniU'rson. — Vommitlee : James IVttigrew, A. Harper, H. B. Clutten, and J. J. Rouse.— &c;Y/i(ry and Treasurer: Alfred H. Farmer, .M, Elizabeth- street, Melbourne. CottejStionirencr* ObrrMpenlmti ikauU iu««r write m Mh Mn of th< pofw. INDIA-TINTING PHOTOGKAPHS. To the Editor. Sir, — All photographic artists should be grateful to yon for the pro- minence you have given this subject, and also to the source from whence it emanated, for undoubtedly it is by similar means true artistic effect will be secured, effects which are otherwise beyond the reach of ordinary photographic resources. To this judicious over-tinting the painter-artist is greatly indebted for many of his startling results in harmony and atmospheric effect ; it is by similar means he tones down his work in a marvellous manner, rendering that which had been previously harsh and without character agreeably beautiful, and thereby enhancing the effect in creating an individuality all his own. The painter names this process rilazing, and, if it is admissible for painters' work, it surely is equally and legitimately available to the sun artist, if produced solely by photographic or chemical means, unaided by brush work, for, unless colour retouching upon the print be admittedly correct, it would be equally unfair to allow what is technically known in the dyeing trade as cutting out or dischariring, as it would be only retouching reversed — i.e., removing instead of adding to the shadows in order to increase the value of the gradations by unorthodox means, and not by the ordinary photographic procedure. But are not similar effects to this proposed India tinting produced by the ordinary processes of photographing, where the positive delineation of the picture predominates over the negative ground colour of the paper ; and was this not pronouncedly evident in several of the more successful pictures of the year, especially in the landscapes where extensive cloud effects existed ? And may we not presume that the eye of the observer frequently supplies sympatlietically the actual India tint demanded, where no discordant wide areas of inharmonious ground colour exists to produce a discord ? This effect is perhaps more evident in pictures of a warm tone, as, for instance, in warm bromides, sepia, and in semi-sepia platinotypes. These India tintings must of necessity be of the most delicate character to be effective, and unfortunately this great delicacy warns us that if permanency be our aim, great precautions are necessary, for, if the presumed increased effects are arrived at by this tinting, it would be very 'distressing that their enhanced beauty prove to be only a temporary excellence. Knowing how readily all delicate tints are degraded or bleached out in other words, how readily they fade away — additional precautions should be adopted in preparing the prints for such tinting, and in selecting the tinting agent. The aniline colours are notably of a most unstable character, by no means suitable for the purpose, and coffee staining, although it may be of a somewhat more reliable nature, it must be remembered varies in svery sample, the colouring matter as a dying agent being largely, and in many instances almost entirely, composed of semi-charred saccharine or umilar matter. The tea staining may be more reliable, but why not smploy some colouring matter of a thoroughly permanent and constant shiu'acter, tannic acid, catechu, indigo, &c. ? There are several of the 3ld-fashioned, and now much disused, dyers' drugs which, in combina- tion with suitable mordants, are not only beautifully delicate, employed as tints, but are of acknowledged stability. One other precaution will in every instance have to be kept oontinu- ausly in mind. Hypo and all the sulphur salts must be thoroughly jliminated to secure permanency, for they are powerful bleaching agents. I am, yours, Ac. , j. p_ January i, 18!I3. » ALUMINIUM MOUNTS. To t)ie Editor. Sir,— On the appearance of this year's Photographic Al>unac, I referred to its pages in hope of finding some mitigation in the charges aaade by our best opticians for aluminium lens mounts, but in vain. Zan any of your readers solve this problem ? If X has a high reputation ?or optical work, should he charge for metal mounts in the same proportion ? As an illustration of the diversity of charges made for aluminium mounts, I send you the following tabla. stituted by letters : — The makcra names are sob- Rapid Fymmetrical 8erie». A. B. 0. D. E. F. e ». d. £ ». d. e .. ii. £ «. d. e : i. £ I. d. FocoB « inches 16 0 0 IS 0 0 17 6 0 10 0 0 14 0 „ n 17 0 10 0 1 5 0 0 11 3 „ 9 1 9 0 1 5 0 1 5 0 OlO 0 0 18 e " 3 1 14 0 1 10 0 2 0 0 0 14 5 10* „ H „ 1 14 0 — — 0 18 10 0 12 0 14 0 „ 14 2 0 0 1 IS 0 1 15 0 1 4 0 0 15 0 14 0 „ 16 S 10 0 2 5 0 2 5 0 „ 18 „ 5 0 0 — 1 12 0 10 0 14 0 „ 20 6 0 0 3 10 0 3 10 0 17 0 „ n 8 0 0 5 0 0 < 10 0 15 0 2 0 0 „ 30 10 0 0 10 0 0 8 0 0 — - Granted that our best opticians are entitled to the full value of their reputation, as represented by the higher prices they can command for lenses mounted in brass, it none the less seems exacting, that they should charge for aluminium by the standard of their optical work. Why should a monopoly price be placed upon a 24-inch lens mount, represented by the difference between 8/. and 1/. os. or 21.? But if we examine further, the charge of SI. for the aluminium mount of a 24-inch lens appears stiU more extraordinary. This lens is three inches in diameter, but if we take a Zeiss lens of Series III., diameter three-and-three-quarter inches, focus twenty-three inches, the charge for aluminium mount. Iris diaphragm included, is il. Deduct 21. Us. for Iris diaphragm, as charged by the same optician for a lens of three-and-threequarter inches diameter, we then arrive at 1?. 5s. for the aluminium mount, tbe same as charged by the cheapest optician. If the cheaper opticians have the truth of their advertisements at heart, concerning the quality of their lenses, I would advise them to attach full Kew certificates at an extra charge. No doubt they would then find a large demand for aluminium mounted instruments, especially in the large sizes.— I am, yours, &c., Philip Evebitt ' January 2, 1893. "TWO MR. BROWNS," To the Editor. Sir, — May I ask your kind insertion of the following disclaimer? In the index published with last week's issue you couple an article on " Photographer's English " with one on " Platinum Toning as applied to Gelatino-chloride Papers," and credit the two to one author. The latter article is from my pen, but I should not like any of my friends to believe me responsible for the former ; hence this note. Photographer's English concerns me not ; I am only solicitous a? to the purity of my own.— I am, yours, &c., James Brow.v. 31, Market-street, Newcastle-on-Tyne, January 2, 1893. [We extend our apolo''^ lofty intekiob -...^IPJS.'i; Ry EDWARD DUNMORE .... 8 WINTER photography. By W. T. WILKINSON s BNTB, ALKALINE Page PYRO- GOLOURLESS GALLOL " MEASUREMENTS OF CLOUD HEIGHTS AND VELOCITIES « AMONG THE BEES WITH THE CAMERA. By T. E. FRESHWATER, F.R.M.8 THE USE OF PHOTOGRAPHY IN PHYSICAL RESEARCH 10 THE PAHA - AMlDOPHKNOL AND AMIDOL DEVELOPERS. By J. B. BRADWELL 11 PHOTOGRAPHY OF THE LIGHT WAVES OF THE SMALLEST WAVE- ENGTHS 11 A KODAK GATHEiUNO AND PRE- SENT.vriON n 11 OUR EDITORIAL TAi UB 1 MEETINGS OF SOCIEiiES 13 RF.CENTLY ELECTED OFFICERS OP SOCIETIES 14 CORRESPONDENCE 15 EXCHANGE COLUMN 1» ANSWSaS 10 CORRESPONDENTS THE BKITISH JOURNAL OF PHOTOGRAPHY. No. 170G. Vol. XL.— JANUARY 13, 1893. IIEVERSED NEGATIVES IN PRACTICE. The subject of reversed negatives has frequently been treated of in times past, but it appears, from queries we have to reply to, that additional interest is now being taken by photographic experimentalists in the various mechanical pro- cesses— particularly since the issue of the Almanac — in some of which reversed negatives, that is as regards right and left, are imperative. AVe shall not here go into the details of all the numerous methods by which reversed negatives can be made, but shall confine ourselves to explaining, for the guidance of novices in the work, the strong and weak points of those most generally practised. In the first place, it must be borne in mind that one of the most important points with negatives for photo-mechanical work is extreme sharpness in all parts of the plate. Therefore it will be manifest that this quality is secured in the highest degree by utilising an original negative instead of having to reproduce it, whatever be the means by which this is accomplished. There are several ways of producing reversed negatives •direct. The one most generally followed by professional workers is that of taking the negative with the aid of a prism, or mirror of plane glass silvered on its surface, placed at an angle, either in front of or behind the lens, for it matters not which position it occupies. In some respects the prism is the more convenient in use, but for large sizes it becomes a costly piece of apparatus. Hence the mirror is usually adopted for all sizes, at least in England. The prism is, however, often used on the Continent. Whichever instrument be employed, this system of working direct is at once the simplest and the best method of obtaining reversed negatives, as it involves no more trouble than making them in the ordinary manner, while their quality is in no way inferior. Reversed negatives may also be taken direct by placing the plate the reverse way in the slide, and exposing through the glass, allowing, of course, for its thickness in the focussing. But it will be obvious to every one that any dirt or scratches ■on the glass, or imperfections in it in the form of air bubbles, Ac, will be reproduced in the negatives, and these defects are not always discoverable with dry plates. Nevertheless, this system is universally followed by some houses who work the " zinco," and what may be termed other rough processes. There, however, the process used is generally the wet-collodion, and this gives the opportunity of careful examination of the glass before it is coated. Where this system is adopted, the ground glass of the focussing screen is usually fitted with its «mooth side towards the lens. The carriers of the dark slide are also supplied with small springs at the comers to press the plate, from the back, against the wire comers which are fixed in register with the ground surface of the focussing screen. Celluloid films, it has often been stated, can be printed from either side without loss of sharpness. This is practically the case with those of the thinnest kind, when used for some purposes. But practical workers tell us that, even with the thinnest, there is a perceptible loss of sharpness in the grain, when they are used in some mechanical processes, even when the greatest care is used with the light in printing. Here is another method of producing reversed negatives that is, perhaps, more extensively followed abroad than it is here, particularly by collotype workers, namely, removing the nega- tive from the glass upon which it is taken in film form, and printing from it with the side that was next the glass in con- tact with the prepared plate. If the negative is made by the wet-collodion process, the glass is French-chalked prior to collodionising. Then, when the negative is finished, a thin sheet of softened gelatine is squeegeed upon it, or the negative is placed on a levelling stand, and a solution of gelatine poured on. When dry, in either case the negative can readily be stripped off for use. Dry plates, specially prepared for stripping, are now articles of commerce, and the negative, after it is taken, may be treated in the same way as collodion negatives, as reg.^rds stripping. If ordinary dry plates — that is, those not prepared for stripping — be used, the film can also be re- moved by treating it with very dilute hydrofluoric acid, after the manner of Plener. Obtaining a reversed negative by stripping it from the glass of course involves more trouble than taking it reversed in the first instance. But the stripped film often possesses advantages over the one on its rigid sup- port, inasmuch as perfect contact can always be ensured in printing, a condition not possible if the glass negative be uneven. If, however, the stripped film be backed with a piece of plate glass, absolute contact in all parts is at once secured. We have hitherto been dealing with negatives taken reversed or with a view to their reversal afterwards. But in general practice a large number have to be utilised that were not, and, more often than otherwise, they must not be tampered with as in stripping, hence there is nothing to do but to reproduce them. It follows, as a matter of course, that, if the reproduction be mode direct from the negative, the greatest possible degree of sharpness should be secured. There are several methods by which this can be done. There is, for example, the method of Colonel Waterhouse, with the thio-carbamides, the reversed action of light method, and the method of Mr. Bolas, by treating a dry plate with bichromate of potash before ex- posure, and some others. As a matter of fact, however. 18 TriE BRITISH JOURNAL OF PHOTOGRAPHY. [January IS, 1893 although they are all capable of yielding excellent results, they are but little used, if at all, by commercial workers. The plan usually pursued by professionals is to work by way of a transparency, either by contact printing, or more generally, with the camera. The latter way becomes imperative when^ as is often the case, a size different from the original is required. The transparency is sometimes made on a dry plate, and some- times in carbon. The latter possesses some advantages over the former, inasmuch as, if the negative be on uneven glass, perfect contact will still be secured through the flexible nature of the tissue, heace a sharper result. For the new negative, either wet collodion or di-y plates can, of course, be employed. Here is another method by which a reversed negative from a transparency can be obtained by contact printing alone. A carbon transparency is made in the ordinary way, and from this a negative is printed on a dry plate. It might be surmised in this case that, as the carbon image is more or less in relief a sharp negative would not be secured. But this, in practice, is not really the case if the usual transparency tissue be employed, as with it the relief is so trifling, that it may be disregarded if tolerably parallel light be used in printing the negative. The extra trouble involved in having to reproduce negatives is often compensated for, inasmuch as then one has the oppor- tunity of securing in the reproduction a negative having the characteristics required for the work in hand, and which the original frequently does not possess. We have not alluded to nearly all the different ways by which reversed negatives are obtainable, but we have indicated those most in every-day practice. CHANGING BOXES VERSUS DARK SLIDES. n. The first idea of the " grooveless " changing box, alluded to in our last issue but one, was due, we believe, to Mr. P. Mawdsley — at present on a visit to this country from America — at least, it was, we believe, in his hands that we several years ago saw the earliest attempt to utilise this principle. The details of Mr. Mawdsley's method, so far as we remember, were as follow : — The box itself in general construction was upon the same lines as Hare's automatic changing box and slide, but without grooves, and weis made of such dimensions as to carry the required number of plates in contact with one another, thus saving a considerable amount of space. We have said the plates were in contact with one another, but this is hardly correct, as they only came in contact at the edges. Obviously, it would be scarcely desirable that even the toughest and hardest of gelatine films should slide in contact with the back of another plate in changing, and, in order to avoid this, Mr. Mawdsley attached to the opposite edges of the back of each plate, by means of glue, a narrow strip of thin cardboard to form a bearing surface, upon which the next plate could slide without injury to its surface. So mounted, half or two-thirds as many more plates would pack into the same space as when the ordinary grooved box was used. In working the changing box the dark slide is attached in the ordinary way, and the box held in such a position that the first plate is at the top of the pile, and, sufficient " play " being allowed for the purpose, it then easily passes into the dark slide. After exposure the dark slide is again attached to the- box, and the sliding lid moved to the side occupied by the last plate, which is now brought into the uppermost position, when the exposed plate can be returned to the box behind the unexposed ones, and so on until the whole have been exposed. On actual trial, we find that twenty plates of ordinary thick- ness, packed hap-hazard from a pile, will go comfortably into the space of a grooved changing box intended to hold a dozen, allowing space also for the necessary number of cardboard strips, so that possessors of existing changing boxes who may wish to increase their carrying space for glass may easily do so to that extent by clearing out the grooves ; but, if films are to be employed instead of glass, in the same space from fifty to a hundred may be included, according to the thickness and character of the holder or carrier. Thus in the simple form of carrier we shall describe later, if used as a double one, a hundred films will easily go into the ordinary one-dozen grooved box ; that is to say, fifty carriers may be used, each holding either one or two films, as may be decided. In order to utilise the double carriers, however, some extra provision must be made, either in the form of a double dark slide — the ordinary one being single — or, perhaps, better still, by providing the means of reversing the position of the slide in attaching it to the box. Such an arrangement was described, at page 568 of our volume for 1889, by Mr. W. B. Bolton. It consists of an attachment in the form of a pair of false jaws fitting on to the box in place of the slide, and into which the slide itself can be inserted in the reverse position, so that, after the whole of one side of the film-carriers have been exposed in the ordinary way, the extra jaws can be placed in position and the opposite sides exposed in the same manner. In 1881, provisional protection was granted to Mr. C. Sands for a changing box and slide in which the principle of the grooveless box was utilised, though the details of construction varied from those detailed above. The lid of the box was fixed, and was provided with two separate openings for the exit and ingress of the plates. The opening and closing of these slots was automatic, being performed in the act of attaching the dark slide by two pins fitting into corresponding holes ; the slide itself, if we remember rightly, was opened and closed by means of a sliding strip of metal. The plates were placed in "carriers" — which, of course, rendered the changing box bulkier in every way than an ordinary one — and it was adaptable to either single or double carriers. As to the respective merits of double slides, and the method of reversing the single slide, it may be pointed out that the former has the advantage of only one changing operation for each pair of plates, though, at the same time, some little trouble is involved in construction, in order to secure correct register of both plates in the camera, and at the same time to permit the carrier to slide freely in and out of the holder. Another point in favour of the double slides is that the exposures run consecutively from one end of the box to the other, while, by the reversal method, they run from one end to the other and back again, so that the first and last exposures in the box will be in the same carrier. This is apt to cause some little dif- ficulty in identifying any particular exposure, if it be desired to develop before the rest ; but, after all, the same, or a gieater, difficulty exists in the case of the continuous films of a roll-holder, and it may be minimised by a careful numbering of the can-iers in their proper order. January 13, 1803] THE BIUTISH JOUKNAL OF PHOTOGRAPHY- 10 Sesults of Solar VhotogTBLV^y' — Mr. George E. Hale writes in Asfronomi/ and Astro- I'hijsits : " In Tiow of the fact tliat the study of prominences, facula, and sunspot spectra by photo- graphic means has now been taken up by several investigators, it seems desirable to bring together the results of the work in this direc- tion which has been in progress at the Kenwood Observatory since April last, 1S91." Tn furtherance of this view he has entered into an interesting series of descriptions in each department, which, though concerned with matters photographic, are not capable of useful ab- breviation, and wo therefore refer our readers to the original paper in No. 109 of the journal quoted, or as abstracted into the Chemivul News, p. 4, No. 1728. A Word of Warning' as to Corrosive Sublimate.— Though a photographer, perhaps, does not expose his hands so much as a surgeon does to the effects of solutions of corrosive sublimate, the fact that this chemical is much employed by some operators renders it advisable to put photographers on their guard by stating the experience of Professor Albert. At a meeting of the Vienna Medical Society he gave an account of tlie ill effects he had experienced, he having used the solution daily in his work as a surgeon. He found that he suffered from dyspeptic troubles, and lately that some of his teeth were falling out, effects which he traced to the absorption of mercury through the skin. It is evident, therefore, that photographers have another chemical to add to the list of those which are injurious to the system, if the hands are immersed without protection in solutions of such substances. Pbotogrraphlngr the BXotion of Vessels.— In La Nature last week will bo found two singular-looking engravings, which, though of photo-astronomical interest, it would be impossible to understand without the accompanying letterpress. The illustrations are, in point of fact, views of an eclipse of the moon taken on board a vessel with exposures of two minutes' duration. The rolling and pitching of the ship has caused the image to describe a series of gyra- tions and convolutions on the plate, which are faithfully brought out on the negative. M. Gaston Tissandier suggests of them that, as a method of registering the movements of a vessel when sailing has often been sought, these pictures furnish a solution of the problem, a negative of the moon or sun being employed instead of, as hitherto' one of the horizon. The Xorth Ziondon Photographic Society. — This ■well-known Society, which represents in its history and connexions the earlier days of photography, and which has numbered among its members many of the men whose names are household words among photographers, is about to move its quarters from Wellington Hall. Islington (where it has had temporary accommodation since the pulling down of its old rooms at Myddelton Hall) to Canonbury Tower, Canonhury-square, arrangements having been made with the Canonbury Constitutional Club, who occupy the premises, for the use of the necessary rooms. The first meeting in the new home will be on Tuesday the l"th inst., when it is expected that there will be a goodly gathering of members to " warm the house," and greet the new Hon. Secretary, Mr. W. T. Coventon, of 50 Highbury-park, N., the late Hon. Sec, Mr. W. Bishop, having regretfully resigned his post under pressure of other engagements, though still retaining his interest in the Society. Differences in Value between Eye and Photo- g'raphic Star Maps. — At the last meeting of the Royal Astro- nomical Society considerable interest was aroused in a discussion on the new star in Auriga, which now appeared to be becoming brighter to the eye, though, in the photographs, it was less bright. The ex- planation offered by Mr. Taylor is as follows, and, as it embraces points of great importance, deserves to be well studied : — As the brightness of the new star diminished, and, presumably, its tem- perature fell, its spectrum would change very considerably. The line at wave length .OOO.i had become by far the brightest in the spectrum -^indeed, was the only line recorded by several observers. A similar cliange of spectrum had been noticed in all temporary stars which had been spectioscopically examined. This line, which appeared to be the characteristic nebular line, was in a region of the spectrum to which ordinary photographic plates were only slightly sentitive, while it was near the region of maximum visual brilliancy of the spectrum for ordinary eyes. The line was therefore taken into account in visual estimations of magnitude, and practically ignored in photographic estimations, and it was a remarkable fact that the presence or absence of this line should have made a difference of three magnitudes in estimations of the Nova. New nxode of Snlargring' the Telescopic Zmagre for Fhotog'raphing'. — Mr. Davidson, reported at the above meeting that he had taken some enlargments of Jupiter, which showed that a newly proposed method would be very useful. It con-sisted in applying, after the fashion of the tele-photographic lens, a suitably corrected concave lens, placed at a distance behind the object-glass. Mr. Maunder had experimented with such an apparatus, in view of the coming eclipse in Brazil and the West Coast of Africa, and had obtained direct images of the moon one and a half inches in diameter. Coverlngr IMCetal with G-lass. — A successful mode of cover- ins: metallic surfaces with a durable coating of glass is a problem which, if successfully solved, would be of vast usefulness in photo- graphic work generally. In case of any of our readers wishing to ex- periment in this direction, we give details of a method which has been suggested for this purpose : — Take 12o parts, by weight, of ordinary flint-glass fragments, twenty-nine of carbonate of soda, and twelve of boric acid, and melt. Pour the fused mass out upon some cold sur- face, as of stone or metal, and pulverise. When cool, make a mixture of this powder with silicate of soda — water-glass — solution of 60° Baume. With this coat the metal to be glazed, and heat in a muffle, or other furnace, until it has fused. This coating is said to adhere very firmly to steel or iron. We see no reason why if, on a comparatively small scale even, a method of surfacing iron with glass, either by the above or other means is possible, it should not be adopted, and thus be of the greatest value for such purposes as the ordinary steel plate of rolling presses is now put to. We are aware that plate-glass beds are supplied to some machines, but it is evident that they are not applicable where heat is applied. A rolling press, suppHed with a plate with a glass surface, which would not ssratch or become rusted like steel, nor break with a certain amount of heat, would be in- valuable. A SEASONABLE PRINTING PROCESS FOR AMATEURS. It is probably owing to the reluctance on the part of the grea majority of amateurs to venture on to new ground that one of the best and oldest of our printing methods is almost entirely neglected by them, in spite of its various advantages, including indubitable per- manence. 1 allude to the carbon or autotype process, which after silver printing on plain arid albumenised paper, takes rank amongst the oldest of our modern printing processes. The principle of the process is so utterly different from most other methods, and the manipulations so far removed in their character from those with which the amateur is familiar, that he may perhaps be excused for imagining difficulties which a simple trial would soon dispel ; for, after the first mastery of the details of the exposure and development, the carbon process is one of the, if not the, easiest and most certain in its results of the large number that are now at the disposal of photographers. In fairly practised hands the beauty and uniformity of the results produced by this form of printing, combined with the ease in working and the small percentage of spoilt prints, is really remarkable, and cannot, we venture to think, be surpassed by any other. But at the present season of the year carbon printing ofiers special advantages over most other methods that cannot fail to recommend it if it be once tried. Its superior rapidity in printing will be especi- ally appreciated during the short dark days of winter, while the less liability of the tissue to injury from damp while in the printing frame gives it the preference over many of the newer processes. From the nature of the sensitive material there is, of course, an end to all difficulty in securing satisfactory and uniform tones, but perhaps the 20 THE BRITISH JOURNAL OF PHOTOaRAPHY. [January 13, 1893 greatest advantage of all is its wouderf ul adaptiWlity to negatives of greatly varying density and quality. It is scarcely too much to say that by suitable modification ia the treatment of the tissue, both in sensitising and development, prints of excellent quality may be ob- tained from negatives vfhich it would be hopeless to attempt to print by any other method. It is, in fact, the process par excellence which does not require a special type of negative, being as well adapted to dense slow printers as to thin, delicate, and even flat ones. In connexion with this quality, it may be further remarked that for getting the best possible result from many of the only half-exposed hand-camera negatives that form so large a proportion of modern work, there is no process that can in any way approach carbon, for, by suitably reducing the strength of the sensitising bath, vigorous and well-modelled prints may be obtained from the most ghost-like nega- tives. Again, in the case of small negatives taken chiefly with a view to enlargement, it is well known that the best results are obtained from these delicate negatives full of detail ; but if direct prints be attempted from such negatives in silver or platinotype, the chances are much against satisfactory results, as these processes require a more robust type of image. But such negatives are just the ones that will give the very finest quality of result in " carbon," and there- fore the process can with still greater confidence be recommended to the notice of the largj army of users of hand cameras of one sort or another. A possible objection to the process may be found by some in the necessity for sensitising the tissue when required for use, as, although it may be obtained commercially in the sensitised condition, it re- quires to be used up within a comparatively short period. This objection, however, may be put on one side, for the worker who will not incur the slight amount of trouble involved in sensitising is not one that is likely to venture far enough out of the beaten track to try the process at all. But it is, after all, a very easy matter, when a day's printing is to be undertaken, to sensitise, over night, as much tissue as is likely to be used, and it will be ready for use in the morn- ing. Moreover — -and especially at tliis season of the yeai' — the sensitised tissue may be comfortably kept for ten days or a fortnight, if iprotected from damp, in one of the ordinary tin cases. The full extent of its deterioration — if such it can be called — when properly kept, will be that it will take longer to develop, and will probably require hotter water; though, as a partial set-off to this, many opera- tors [claim that a better quality of results, as regards fineness and gradation, is obtained [with tissue that has been sensitised for some days. I do not suppose many of your readers will venture to the extent of making their own tissue, nor is there any necessity to do so, unless it be for the sake of producing special colours not found amongst the commercial samples. These are offered in such a variety of tones of the usual photographic kinds that for ordinary work there is no necessity to go to the trouble of preparing for oneself. But if by chance it should become necessary, there is not the slightest difSculty in the process, far less, indeed, than in the preparation of an emulsion, while the quality of the product need be in no way inferior to the commercial article. It is true that in the manufacture of the latter elaborate machinery is employed, as well as a large staff of more or less skilled assistants ; but these are only required by reason of the magnitude of the operations and the necessity for having everythin" done in the most expeditious and economical manner possible. (To he concluded.) W. B. Bolton. CONTINENTAL NOTES AND NEWS. Sliver Ziactate Plates.— Before the Antwerp Stction of the Association Beige de Photographie, the President, Mons. Joseph Maes, recently gave a demonstration of the development of some transparencies on plates prepared with lactate of silver. The whites of the images were said to have been very pure, and the blacks very int«nse. The plates are rapid enough for reduction in the camera. " The Question Box."— Before another Section of the same Society one of the members, Mons. Ed. .Sacr<5, brought forward (as he had already done several times) a proposition for the institution of a " question box," so that members might have the opportunity of sub- « mittiug questions without disclosing their identity. The report does not state whether M. Sacre's proposition was carried, so that we may suppose that that gentleman will bring the subject before the Section again. Among the few English Societies who have a " question box " we are not sure that, as a means of enabling an inexperienced member to obtain information upon a matter which he is reluctant, for fear of ridicule or criticism, to introduce in the usual way, it ia of any practical use, it being as a rule more honoured by neglect than by use. Sodium Sulphate In the Developer. — Herr Pippel, in a German contemporary, recommends the use of sodium sulphate (Glauber's salt) instead of the sulphite in the developer, it yielding clean negatives of a rich black colour. For a properly exposed plat© he recommends immersion for a few seconds in a bath of — Pyro 1 gramme. Saturated solution of soda sulphate .... 20 to 40 c.c. Water 100 c.c. to which, being returned to the developing measure, is added 2 to 10 c.c. of a saturated solution of sodium carbonate, develop- ment then being resumed with the mixed solution. For over- exposure, bromide ; more detail, an increase of carbonate ; and for under-exposure, more of the latter, plus 20 to 30 c.c. of the sulphate solution, are recommended. A Black Stain for Wood. — The photographer who makes his own apparatus may desire to know a good and cheap black stain. According to Science en Famille, the following fulfils those require- ments : — Extract of logwood 15 grammes. Chromate of potash 2 „ Water 1 litre. The extract of logwood is dissolved in boiling water, and the chromate then added. The colour of the liquid is a deep violet, which changes to a pure black in contact with the wood. Vibration of Photogrraphlc Apparatus, dic. — To- judge of the steadiness of photographic (or photo-micrographic) apparatus, &c., a contemporary recommends that a glass vessel, charged with mercury, be placed on the top of the camera or other convenient position. The least possible movement of the apparatus is shown by the numerous and varied little waves which appear on the surface of the mercury bath. These minute undulations are immediately perceptible to the eye, which sees, as it were, the images obtained by reflection on the brilliant surface of the mercury. Writingr on Glass. — For "matt" inscriptions on glass it is suggested to dissolve in .500 grammes of water 36 grammes of fluoride of sodium and 7 grammes of potassium sulphate, and in another 500 grammes of water 14 grammes of zinc chloride, 65 grammes of hydrochloric acid being added. For use, equal parts of the solution are mixed, and the inscription made on the glass with a pen or brush. In about half an hour the lettering so traced will present the customary " matt " appearance. Varnishing' Zinc Trays. — When zinc trays, &c., are used for washing plates or prints, says " Ki-Non " in L' Amateur Photo- (jraphe, the deposited hypo reacts on the metal, which, it coming Into contact with prints, stains them. This, he says, may be avoided by varnishing the vessel with bitumen of Judea (5 parts dissolved in 100 parts of benzol). The varnished vessel is placed in sunlight in order that the bitumen may be rendered insoluble. He advises two applications of the varnish, and to repeat the operation as occasion may require. Impurities In Bedudng^ Agrents.- As the result of an examination of the developing properties of gaiacol, as alleged by Colonel Waterhouse, Messrs. A. & L. Lumiere state that that sub- January 13, 1893] THE BRITISH JOURNAL OF PHOTOGRAPHY. 21 stance in the purified form does not develop exposares on the silrer haloids, the developing action being- due to the impurities with which it is contaminated. Treatinjif of the developinjf powers of certain substances at a very high degree of dilution, they mention the interesting fact that an allialine solution of para-amidophenol at the etrengtli of 1 : 10,000 is sufficient for the purpose. WINTER TROUBLES. It may seem something like " locking the stable door after the horse is stolen,'' to raise a note of warning after an accident has happened, but as we can scarcely hope that the present thaw closes our w^inter, the same trouble may occur to others that has fallen within my own experience. This, though perfectly explicable, is to me, after many winters' acquaintance with chemical and photographic apparatus, entirely novel in its form, and, as a very simple precaution will prevent its recurrence in other cases, I make no excuse for narrating the circumstances. Just previous to, or in the early part of the late severe frost, a large and valuable porcelain dish, after being used for washing a batch of prints, was roughly wiped out and reared on edge against the wall in one of my work rooms. The dish, I may say, was, up to this time — so far as I was aware —perfect, the enamel not even being cracked, as is so often the case with such dishes, even after comparatively little use. Judge my astonishment, therefore, when, on going into the room one day, I noticed a crack extending from one of the lower comers, as it stood against the wall, to nearly the centre. A rough examination led to the conclusion that the crack was a new one, probably the result of a recent knock, though I could not remember having administered one, and nobody else had had access to the dish. The crack at this stage did not appear to be a very serious one, not sufficiently so to cause the dish to leak or to unfit it for the purposes of washing to which it was usually applied ; but in order to guard against further damage, it was placed more carefully in its proper rack, one of a series of shelves on which it rested in the horizontal position. Here it remained for probably a week until I required it for use again, when, on taking it out, I was disgusted to find that not only had the crack extended nearly right across the dish, but it had become at its starting-point at the edge nearly an eighth of an inch wide. An examination showed that the crack was filled up along its entire length with ice, and this gave a clue to the cause ; and a sub- sequent closer and more careful scrutiny proved my original sup- position to have been coiTect. A very slight crack, possibly not visible at the time, in the lower corner as the dish stood against the wall had absorbed a certain amount of moisture, which in freezing forced the edges of the crack wider apart, and probably opened it up a little in length, and into the newly opened portion fresh moisture found its way by capillary attraction, to be frozen in turn and still further extend the damage, until the wedge of ice, as I have said, had opened the crack at its widest to nearly an eighth of an inch. In this condition the dish was perfectly firm, the two portions being held together by the intervening strip of ice ; but, on pouring a little warm water into it, the expansion of the material caused the fracture to extend, with a faint report, to the opposite side of the dish, and, the cohesion of the intervening ice being simultaneously destroyed, the two portions fell apart. It required but a brief scrutiny to show that a crack scarcely two inches long had existed in the upright side of the dish, and through only a portion of its thick- ness : this much was evident from the slight discolouration of that portion. The rest of the fracture caused by the ice was perfectly white and fresh. Curiously enough, though this was the first occun-ence of the kind that ever came under my notice, within a day or two a precisely similar accident happened in the domestic department ; a large jug, having been hung up damp, was fractured in the same manner, and fell in pieces when warm water was poured into it. The lesson taught is a very simple one, namely, never, but es- pecially in frosty weather, put poixolain, or similar vessels, away damp. The danger is greater in the case of dishes, jugs, or other utensils used for pure, or, at any rate, ordinary water, than those con- t.^ining solutions of chemicals," as the latter will, to a certain extent, prevent, or arrest, the freezing of the liquid. Still, the careful man, who always washes his dishes or measures before putting them away, would be wise in carrying his care a step further, and making it a point to systematically dry them before considering his task performed. Neglect of this simple precaution has cost me a us«ful and valuable dish. It will surprise many amateurs who have not tried it, how small aa amount of heat will " keep the frost out of a dark room. A plan I have adopted with satisfaction for several years past, consists in keeping burning, in my sink, when not in use, an ordinary benzoline lamp, over which is placed, on a retort tripod, a tin can, containing about three pints of water, which absorbs and radiates tlie heat that would otherwise be diffused and wasted. The shelves on which my bottles are stored are in close proximity to the sink, and these get the benefit of the genial warmth, though the far-off comers of the room may be below freezing point. With this simple arrangement, not even " saturated " solutions of oxalate of potash, or sulphate of iron, need give any trouble in the coldest weather. The cost is less than a penny yw diem. Old Collodion. *- SOME CONTRIBUTORIES TO ARTISTIC RESULTS. [Hackuey Photoyrapluc Society.] My intention in engaging your attention to-night, with some of the minor matters which may or may not contribute to the artistic result of our work, was not to deliver a discourse of a learned kind, but rather to select one or two matters, and, having expressed some views thereon, to have left the thing to general subsequent discussion. ■Those who are sufficiently serious in tneir endeavours for improve- ment probably have as much solid food as they can digest provided by the weekly journals, so that I sometimes think our lectures and essay readings at society meetings are not always the beat possible appointments for the good of individual members. Thus, for instance, as a contributary to general good effect, I might have selected frames and mounts. I should have raked together specimens of mouldings and cardboards from the four quarters of the earth, and come ladened like a picture framer's agent. I should then have siiggested the respective merits of black and gold, white and gold, English gold, and the gold which, tho«gh it glitters, is made in Germany, dark woods and light woods, black or brown. Then there would, of course, be plushes and silks and wondrous fabrics to be considered ; there is the clear white glass and the greenish glass, with all sorts of specks and bubbles in it, and a hundred other aspects from which one may use- fully consider and discuss the framing and mounting of our pictures. It is an important matter ; a good picture is worth well mounting, and, in order to decide on the mount most suitable, no ordinary care, judgment, and taste are needed. Exhibition Frames. As it is, however, I have none of these specimens here, nor nerhaps is it necessary to have such. Most of us have seen a few exhibitions, and in that case have had opportunity of seeing every kind of frame which human ingenuity could invent, and we must in many cases have been convinced that with some competitors the frame was the thing exhibited, with some apology for a picture thrust in the opening just to fill it up. I have thought sometimes that in the frames you may find an index to the exhibitor's character and condition. There's the man of magnificent ideas, but lacking the means of carrying them out, glorious in florid gilt, crimson flock inches wide, and he who has money and loves to spend it, who frames his things regardless not only of expense, but of the fitness of things. The man of original ideas is soon recognised, and often his originality gets the better of his judgment, and the unconventionality becomes affectation, and he who copies or imitates is apt to imitate blindly, and misapply the models which he has set up. And now, if one should say, \\'hat amongst the many ways of framing and mounting is the best which will secure for me the com- mendation of those -n-ho judge ? I should say that your good taste in framing will be best displayed when your frame itself .is not noticed. No paradox is this, but sohd truth, and hence one advantage of having every picture in the room framed with uniformity no one attracts more than another, and so we shall escape that most irritating remark, as open-mouthed wonderment says, " What a beautiful frame ? " I well remember visiting Mr. F. HoUyer's exhibition of photographs at the Dudley Gallery privately, with some half-dozen confreres, and imme- diately on entering the room each one of our number exclaimed, or his'looks expressed it, " What capital framing ! " Then we laughed that we too should have done what so many have been ridiculed for doing — admiring the frames before thinking of the pictures. But do not mistake me, the case was very different ; it was not actually the frames that awakened remark, but the excellent judgment shown by the artist in using such material, and of such colour that, although we could if we thought about it tell what manner of frames were there, yet throughout a walk round the gallery one was never conscious of frames at all. The pictures might as well have been let into the walls of the building, and be«n part and parcel thereof. To my mind that is ideal pictmre-frauing. » 22 THE BRITISH JOURNAL OF PHOTOGRAPHY. [January 13, 1893 Thb Right Frame and Mount to Usr. Can you remember, for instance, some picture, some photograph, which pleased you a good deal, but, if asked, you cannot remember anything of the mounting or frame ? Well, then, be sure that was ju8t the right frame and mount for that particular picture. How are you to imitate it it you can't remember what it was like ? My good sir, no one suggests— or, at least, I do not— that you should imitate that or anything; what suited that picture may not suit yours ; your only way is to select such a surrounding for your picture that it shall be wholly forgotten and kept in subjection when looking at the picture. Someone challenges me by referring to the ponderous mass of gilt which usually surrounds the best of paintings. AVell, the way to avoid attracting attention is sometimes to do the time-honoured ordinary and usual thing, and so it has become customary to put oil paintings in heavy gold frames. Perhaps the safest thing is to follow so widely adopted a custom. Still, we may notice already in some of the newer picture galleries the conventional gold frame does not rule supreme, quite a number of blackwood mouldings being introduced ; moreover, the artist's fine contempt for the frame-makers' craft is seen inasmuch as somewhat shabby and far from new frames are employed, but with just that amount of good taste which, without effort or intention, saves the artist from error in the opposite extreme. I have hinted that the conventional and ordinary may, when we are in doubt, be the safest course to adopt. I give this as a point for dis- cussion ; and further that, all things considered— and I must emphasise this qualification very strongly— all things considered, and allowing for some exceptions, the safest and best mounting for our photographs, as taste and feeling goes at present, is the plain wood, oak or dark colour, and the cream-toned mount on a white board, as has become very widely used. But I fancy already some one is beginning to resent my expending so much time in talking about so dry a subject as frames and framing. Cutting Down Pkints — The Knife and Scissors. Well, then, if I had had proper time to prepare my subject for you this evening, I should have brought here to-night a printed photo- graph cut down to all manner of sizes, and I would have discoursed on the scissors and knife as a powerful contributary to final artistic result. As it is, I have brought no examples ; I content myself with submitting to the suggestion that, as a rule, we are all too much afraid of using the knife. We are too inclined to be influenced by the standard commercial sizes ; if 124-10 is the size of our plate, we must flu every inch of it ; this at least seems to be the prevailing idea. Even those who are thoroughly acquainted with the often-used arguments in favour of liberty of size and shape, still, as it were, reluctantly fall into the groove, and strive more than for anything else to make the subject flU the entire plate. There is nothing new in all this; our teachers have been pointing out the advantages of cutting down our prints so as to improve the composition for years past, still we may notice the same old faults com- mitted on all hands, for want of a little strength of mind in putting in the knife and cutting away some pretty little bit, some favourite comer, because, although good enough itself, it does not help the picture as a whole — and it does require no small strength of mind, as I myself know full well. Am I not conscious of being a grievous sinner myself in this direction ? It is hard to deliberately cut away and destroy some, it may be, particularly intetesting object, some- thing especially well rendered, because it does not help the picture as a whole ; but its good qualities, technically considered, must be no reason for saving it. By this I do not, of course, mean that the chief and central object in a composition is to be cut away, though it sometimes may happen that the object we had intended as an im- portant item in the scene does not quite come up to our expectations, and we can secure a satisfactory picture by reducing the size of the print very considerably. To give you an example, I not very long ago spent a day with the camera on the marshes below Old Win- chelsea. Some of you may know the spot, and will remember how delightfully the abrupt hill on which Winchelsea is built rises from a vast green level. Here black-faced Kentish sheep browse by thousands, and I conceived the idea of getting a group of sheep on the left of the foreground and including the hills in middle distance. And so I did, yet, when printed and finished, the thing was far below my expectations, and I could not for a long time decide what was amiss. I was so intent upon my picture of sheep that it never occurred to me that the sheep and the hills had no connexion until, •with a boldness of which I am not often capable, I cut the thing in halves ! Now, I found I had, by two strokes of my knife, constructed a picture in the half which still contained the hills, but ; alas I the group of sheep, which I had waited hours for, which I had wearied my attendant in driving and coaxing into position, were abandoned — the object of all my care and patience is cast into the waste-paper basket. When producing the first print from a negative, I usually lay it out flat, and take four strips of brown paper and lay them so as to tem- porarily frame my print ; then I shift them in a variety of ways, each time including within their boundaries a different part of the print. By this means I ascertain what part of that landscape is best retained and what best discarded, often with the most heart-breaking results. How often has a 1-5 x 12 view, made with great care, been reduced to as small as 6x4? And when I have recalled the real hard work and fatigue which attended the carrying of large camera and heavy apparatus, it seems a good deal to have gone through for the sake of a little print. Size and Artistic Effect. Closely akin to this is the notion that size has a good deal to do with artistic effect — an erroneous idea that a large picture is artis- tically superior to a small. Possibly some scenes are more suitably produced on a moderately large scale ; but, as a general rule, I do not hesitate to say that a quarter-plate may be as completely (nay, often is) a work of art as your 24 x 18. Now, Mr. Chairman and gentle- men, if I had prepared for this evening, as I ought to have done, a should have submitted to you occular proof of this by exhibiting I print 3 x 4 by the side of one 30 x 40 ; as it is, I must put it to you that size, that is measurement by inches, contributes nothing of artistic effect. The completely successful picture is the one which, whilst giving a pleasant impression, does not make its size felt. A little picture may be of such a character that the spectator is not made conscious of its restricted size ; the selection of subject, and the treatment of it, may convey a sense of breadth and largeness, which, to my mind, is a most important characteristic. Why Adopt a Rectangular Form of Picture ? Why do we usually adopt for nearly all subjects a rectangular form for our pictures ? The eye does not form a rectangular figure when looking at nature, but a vignetted ellipse. It was pro- bably convenience in the first place which decided the matter, and then custom grew upon this, so that now we use a rectangular form because, being conventional, it attracts least attention, and the spec- tator is unconscious of the boundaries. The arrangement or composi- tion of every picture should be such that its boundaries should not be felt to be restricting, and there should be such interest within the conflning lines that trie eye feels no desire to wander, and the mind no wish to inquire of what else the world was composed, or what came next in the landscape panorama. I might suggest such arrange- ments of lines, such combinations or such dispositions of central objects, and so forth, which I have myself found to assist in this direction, but beyond this neither I nor any one else can tell you how to make your small picture overcome its impression of littleness. It is a thing to be found of experience and observation, and to be attained as others have attained it — on the steep ladder of many failures. A Definition of Artistic Effect. I should not have to look very far back to find the time when it would have been necessary for me to preface such remarks as I had intended making, and have already been stumbling over, with a definition of what I meant by artistic effects : but I am seriously glad to believe that in some sense we have got beyond that necessity, and that, in a general manner at least, most of my patient audience have some idea as to what an artistic picture should be, namely, not an imitation of nature, or a copy of nature, but rather an interpretation, that is, a general and broad representation of the impression made upon the artist's mind by the scene, and containing an e.ipression of the sentiment or idea xohich it aviakined. Before exhausting the list of factors which might be considered in the light of contributories to artistic effect, we should have to dis- cuss : Figures supplementary to a landscape scene, also cattle and the like; and we might note how and when they contributed or detracted from the well-being of the picture; also clouds and the employment of a second negative ; colour, whether of the image pro- duced or of the paper used, which may make or mar our work ; position of Ught and the amount of it, also the relative tone of various parts ; and we should hardly escape discussing the question of focus and amount of detail permissible, and you know if we started that topic to-morrow's sunrise would find us still at it, and this room bearing close resemblance to a battlefield or the sequel of an Irisli wake. "An Evil Reputation." Has any gentleman here, I wonder, ever had an evil reputation foisted upon him which he does not deserve ? Has any one who, being a man of very temperate habits, found suddenly that his neigh - January 13, 1893] THE BRITISH JOURNAL OF PHOTOGRAPHY. 23 bours have quietly ftffreed amongst themselves that he is much addicted to wliifky drinking, and that when he goes out of an evening, professedly to a meeting of the IlnckniAr Photographic Society, his best friends spread the report that the Hackney Photo- graphic Society only means a wild bacchanalian revel, or a disguise for entering on a housebreaking expedition ? If so, he -will be able to sympathise with ine, for somehow my photographic friends have decided amongst themselves that I believe in nothing but photographs put confusedly out of focus, printed on exceedingly rough papers and in a reddish-brown colour fallaciously called sepia. A. HOKSLBT HiNTON. AN APPARATUS FOR THE DEVELOPMENT OF PHOTO- GRAPIUC PLATES WITHOUT THE USE OF A DARK ROOM. 1^ Joamal of the Society of Chemical Industry.] Thb apparatus which I bring before you to-night was in use for two months before I learned that a " portable developing box," similar to it in many respects, had been described by Dr. T. W. Harvey in the International Annual of Anthony's Bulletin for 1888. But as the apparatus about to be described differs from it in principle, and is based on the photo-chemical investigations of Messrs. Hurter & Driffield, I have thought that this communication might be of interest to the Society. In the paper which we had the pleasure of listening to last session (this Journal, IX., 4.55-460), Messrs. Hurter & Driifield have shown that of all the conditions involved in the production of a " perfect negative," those relating to the exposure are by far the most im- portant, and if the exposure factors are so adjusted as to give the " correct exposure," the development is of secondary importance, as the density gi-adations of the negative are entirely due to the action of the light. It therefore occurred to me that, with a correctly exposed plate, development might be carried on quite mechanically, as the required density can be regulated by the length of time of development. On trying the experiment of allowing plates which had been exposed by the aid of Hurter & Driffield's actinograph to remain in the ferrous oxalate developer for different lengths of time, it was found that, with the same quality of plate, satisfactory negatives could be ob- tiuned in ten minutes with a strong solution, and in fifteen minutes when the solution was diluted with an equal volume of water. AVhen the time required to obtain a suitable printing density had been ascertained for a particular plate, it was found that there was nothing gained by watching the progress of the development, and consequently the dark room might be dispensed with if means could be found to keep the plate in the dark during development, and in its transference from the dark slide to the developing vessel. In order to attain this object I have devised the apparatus which I have named a dark developing bath. It consists of a metallic case, A (fig. 1), only slightly larger than the plate for which it is intended, which can be closed light-tight by means of the lid B. It is furnished with two tubes, one, C, entering at the bottom of the bath, which can be connected by a piece of india- rubber tubing, E, to the funnel D; the other is near the top, just above the level of the plate P. The former serves to introduce the developer into the bath, and the latter, F, allows the air to escape and also acts as an overflow. The funnel, D, and the indiarubber tube, E, are supported by means of the hooks K K, which fit into the eye L. The tubes are so bent that no light can enter the bath. An end view of the bath is shown in fig. 2, in which a movable hook, I, fitting into the socket, J, serves to fix the bath to any convenient support. A section, Fi^. 3, shows the plate P, the film side of which is kept from contact with the side of the bath by means of the metalUc strips H. When the bath is intended for the development of films or paper prints, it is furnished with a carrier (fig. 4) into which the fihn or paper is inserted before being put into the bath, and when required for the development of several plates at one time, it is constructed with grooves as in an ordinary plate box. The bath is used as follows : — The dark slide containing the exposed plate and the bath are placed in a changing bag, into which it is only necessary to insert the hands. The plate is then transferred from the slide to the bath, care being taken to keep the film side towards the back of the bath. After being closed, the bath is withdrawn from the bag into day- light, and fixed vertically to any convenient support by means of the 1---1. j^ vessel is placed under the overflow tube, and the inlet tube hook. is attached to the funnel, which after being filled with the developing solution, is raised and lowered several times, to alternately fill and empty the bath, and so ensure the removal of air-bells from the surface of the plate. After standing sufficient time to complete the development, the solution is run off from the bath. The plate_i» /Oc ^ -^4 -3 washed by running water through the bath (either by means of the funnel or by attaching the India rubber tube direct to a water tap), after which it is taken out, in daylight, and "fixed" in a covered tray. If it be desired to " fits " entirely in the dark, the operation may be conducted in the same bath or in a similar one to which the plate has been transferred in the changing bag. The final washing of plate may be done either in the bath or in the usual way. The best developer for use with the dark bath is ferrous oxalate, on account of its property of not producing " fog," even when a plate has been left in it for an hour (Hurter & Driffield, loc. cit. p. 459). It should be made just before use from the following solutions pre- pared according to Thomas's formulse : — No. L Potassium oxalate 300 grammes. Potassium bromide 2'2 „ Water to make 1000 cc. No. 2. Ferrous sulphate 400 grammes. Sulphuric acid 3 cc. Water to make 1000 „ To four parts of No. 1 add one part No. 2, and water to make eight parts. When the developer is used at once with Thomas's " Extra Rapid " plates, from twelve to fifteen minutes in the bath at about 15° C. is- sufficient to give a satbfactory negative, if the exposure has been correct. The time required to obtain a suitable density is found by placing the exposed plate in the bath and adding the amount of developer required to till the bath, in four equal portions at intervals of five minutes. Four densities are thus obtamed by developing for five, ten, fifteen, and twenty minutes respectively, from which observa- tions the time that gives the desired density is selected. A very small bath to contain four plates (a quarter plate cut into four) is useful for the development of test plates exposed in the camera on a landscape in order to ascertain the speed of the plate, as recommended by Mr, V. C. Driffield {Photographic Soc. Reporter, April 1889). A developing bath constructed as above, besides enabling plates to be developed without a dark room, has some other advantages over the ordinary developing tray. The bath being used vertically pre- sents a very small surface of liquid to the air, thereby preventing the rapid oxidation of the develpper. As the solution is introduced at the bottom, imder pressure, it flows up evenly over the plate, carry- ing the air before it and so prevents air-bells. The plate is com- 5.4 THE BRITISH JOURNAL OF PHOTOGRAPHY. [January 13, 1893 iletely iminersed in the S'olution during development. The bath ieing quite lightrtight, there is no risk of " fog " from access of light to the plate, an^ it is therefore especUUy suitable for the development ef isochromatic and other very sensitive plates. The tubes attached enable the solution to be readily run off and replaced by one of altered composition, and also allow of a continuous flow of developer through it. As this apparatus has been designed for the development of correctly exposed plates, any plates developed in it which are either over or under-exposed will be more or less defective. If, however, the exposure has been nearly correct, a passable negative will be obtained, but if it has been wide!;/ different from the correct one, as no provision is made for remedying the defect, the negative will be a failure, but if such a result should lead to more attention being paid to the exposure it will not be altogether to be regretted. Alexandbk Watt. "BREADTH." Mb. Tulloch's letter has started a subject which will bear much jeflection, and I wonder if nineteen out of every twenty photographers ever think about this artistic quality in the production of their prints, or how many understand what it means, and yet it is the one chief olijection which painter artists raise against photography, that photo- graphs are so deficient in " breadth." Thousands of amateurs have taken up, and will take up, photo- graphy as a pastime who have never had any training in drawing sr painting in oil or water colours, and therefore have had no chance of becoming acquainted with terms used in art and their meanings, and it naturally follows that they cannot apply these principles to their work in the form of study of composition, light and shade, and breadth of treatment, and it is mainly here that others who have enjoyed such opportunities, and have been draughtsmen or painters lefore they took up photography, step into the front ranks, and show superiority in their photographic work, and the best thing those who desire to excel can do is to take a term of training in any of the Bumerous schools of art now existent in every town of any size, and «o qualify themselves to see in nature teith educated eyes things they BOW look at with a pleasing, but at the same time artistically sneducated, effect. If I were asked to define in as few words as possible the meaning i>f " breadth " in a picture or photograph, I should be disposed to say that it is the absence of spottiness, or the reverse of the effect of spottiness, and that abundance or minuteness of detail in the picture or print has nothing whatever to do with it either one way or another, provided that detail (though microscopically sharp) is kept in subordination to the general tone of the parts of the picture or print where it ej:ists. "Breadth" is a quality of great convenience to the painter; it enables him to ignore the wealth of detail which would cost him infinite time and labour to produce with brush or pencil, and which, if produced, would distract the interest of the spectator and attract attention, to the detriment of the principal " motive "' of the picture. Therefore he subordinates detail, or, if painted in, he "glazes" it over and tones it down with some transparent pigment which, whilst it prevents undue attraction to the eye, permits it still to be found by »ny one who seeks for k. Breadth is so essentially an artistically created quality that it is not frequently seen in nature, except under special conditions of light and shade. This is sufficiently evidenced by photography itself, from the fact that so few photographs possess it. If any one desires to study the effect of '• breadth " in natural landscape, they must be on the watch for it soon after sunrise on summer mornings, or in the late afternoon and evening, when the sun is at a comparatively low altitude, and how few photographers ever attempt to get their negatives taken at such times. AVait till the sun reaches an altitude of sixty-five or seventy degrees, and it becomes very difficult to find " broad'" effects si Kghting, because every object becomes so generally illuminated that "spottiness " in the lighting is universal, and it is only by selec- l«Mi of larger masses of shadowed subject that " breadth " can be »btsdBed. _ A«ain, aft«r a shower of rain, when every atom of foliage sparkles HI. the light with wet reflecting surfaces, the quality of breadth is absolutely impossible to secure, and such a subject may be taken to axpress a quality the very opposite of "breadth." The moral is, Don t take any negatives under such disadvantageous circumstances, Bowever beautiful the view may appear to your senses ; the result in the photograph must be general spottiness, distraction to the sight, md vexation to the perception of artistic friends. How, then, U " breadth " to be secured in our photographs ? In two ways — partly photographic and partly artistic. First, by careful study of the time of day, early or late, when the subject is broadly Ut, and taking negatives at such times. Second, by imitating the work of the artist and toning down in the finished print such obtrusive spotty lights as tend to destroy the breadth of the picture, and which have been found impossible to avoid in the natural view. The followers of the fuzzy definition school had the attainment of this quality of breadth very strongly in view in adopting the " out-of- sharp-focus " principle, but it appears to me that it is a mistake to suppose that it can be attained by that means. The broken effect of spotty lights amongst broad shadows is just as apparent, though not so strongly accentuated, when they are thrown out of focus, and the distracting effect is the same, and, therefore, nothing is gained by diffusion of focus ; but if these disturbing lights, which idll come where they are not wanted, can be toned down so as not to be obtrusive, the effect of breadth can be secured icitfumt the sacrifice of good definition, which has such a charm in photographs when well managed, and which artists enjoy as much as any one else when kept down in proper subordination to the general tone and lighting of the picture. Another method of securing breadth to a large extent is by giving full exposures. We all know that the consequence of under-exposure is great contrast of light and shade, and the more the negative is forced to bring up latent detail in shadows the more accentuated becomes the contrast and the spottiness. The reverse is the case with over-exposure, as the proper balance of contrasts is overdone, and general flatness is the result, which constitutes an exaggerated and spurious kind of breadth. Those who delight in so-called " brilliant " and " sparkUng " negatives, and aim at sufficiently short exposures to secure them, often err by obtaining negatives deficient in the quality of breadth by reason of this very " sparkle " and " brilliance," and it is just the critical point in Correct exposure to obtain the true effect of breadth without either spottiness on one side or flatness on the other, and it is only to be got by sufficiently fall ex^oeaxe and restraint in development. This will secure it photographically, but, allowing for accidents in timing the exposure, or iinpossibilities in obtaining perfect natural lighting, it is as legitimate to adopt the artist's method, and to tone down objectionable lights in the print, as it is for him to " glaze " or " scumble " his effects on his canvas, and, as a final resort, is often the only way to obtain the desired effect of breadth. " Lux." THE PINHOLE SOCIETY'S OUTING. It was resolved that the members of the Pinhole Society should have an outing. Fine weather brightened the heart of the amateur, and he in return spent many evenings in brightening his beautiful set. Then came the difficulty, what part of England should be favoured by the Pinholes on this particular day ? Sixty members each selected, and hard indeed was the task to get the remaining fifty-nine to go in nnison. All expressed their objections, and the chairman found it a very lively meeting. Some had taste for water pieces, others wanted landscapes, a few preferred figures, while one had a strong taste for trees, and a good house of re- freshment near. Finally came a mutual settlement, every member promising to be at the appointed spot, and to bring a friend if possible. When the morning arrived, the full muster numbered four. The re- mainder of the society had, in the meanwhile, decided if the others would not, they would go to the spot of their own choice. So they went. The four turning up together were bent upon the real thing — a jolly day first, and pictures second. Away steamed this little party, all loaded with oddities connected with, but never separated from, the art of their heart. When a party of camera men meet on a rail car, all charged with hopes and strong tobacco, what talk ! The usual lady andgentlemen passengers sit by and wonder, and again wonder, at the strange language they hear flow so fluently from the lips of the.se camera men. The gentle sex are said to talk, but are not in the running with a merry party of photo- graphers. Processes and developers containing the whole letters of the alphabet are rattled off with the greatest speed. A good photographic gossip is far more gratifying than an outsider can imagine. It comes to all who ride this hobby horse. And so the four men of the camera sped on. Each knew the best developer and worst make of plate, and all four disagreed thoroughly and candidly over each. One's success proved another's failure, and so trouble came and trouble went. More talk, more smoking ! Grand old meerohaum ! strong old briar ! all burning and roaring at full blast. The male and female passengers slowly but surely become saturated with long words and tobacco smoke. They wonder, as the train dashes on, where and what are the stations. To see is iiupossible, and with clatter of triin and language of a country porter without and confusion of tongues within, they begin to feel uneasy. They shrink from asking a question of the camera men, as to do so would break their run of words, for they now think photography a sacred science. January 13, 189:tl THR BRITISH JODRNAL OF PH0T03R.\PIIY. 25 and photographers strangely wonderful men, wlule muoh regretting they had allowed themselves to remain so long in the same coinpartnient. At last came a pause, the four men knock their pipes on the edges of their shoe-leather, put them away to the pocket nearest the heart, and, with camera-case on the tripod slung over the shoulder, each makes a long down step, and all four, witli packs and hags, are safely landed at their destination. The two passengers also get out, and push hy with a rapid farewell glance. After a short halt, oh they go, until the leader gives the word, " Halt ! present arms, and blaze away 1 " Then, in quick time, comes the sight of tools in their multiplicity. Here you have demon- strative proof how some carry the fullest detail in all the likely and unlikely requirements of his art. One has a range of lenses from decimal focal length nothing, to that eight times the boundary length of his plate, with which he says he can "bring down" an object as near as his eye- lash, or as far off as the moon. Everything he caries opens one into another, with the ingenuity worthy a Chinaman. He even wears a wonder- ful suit — all secret drawers and pockets. Touch a button, when out comes a dark slide. Pull a string, when out hops a pretty little magnifying glass. From a fob comes the neatest finder possible ; also quite a portable jhoto- graphic store. If you are in doubt as to the light he, in a jiffy, hands you the very latest actinometer, supplemented with a thick volume of closely printed instructions. The standard tables of exposures, position, and light are also there to the least degree, with such information— " failures " cannot be thought of, least of all explained. Another of the four has a rough-looking lot indeed ; he feels some reluctance to open up beside his elaborately equipped comrades, so, under the shadow of a big tree, he raises gently and quickly his cheap set to its stand, which is, in itself, a noble piece of English oak, heavy enough to resist the quarter or 1 5 X 12 camera, which retains a power, like Sandow, for more weight. The best-looking thing he carries is the black velvet focussing cloth, and soon it acts the part of pall to his seedy camera box. How, all day, he so cleverly and, in a way, seemingly unintentionally arranges this cloth to always remain without exposing liis lot, is worthy one's admiration. His slides are stronger than highly polished mahogany ; they require no brass bindings, being in themselves sheet iron. His exposures are made by his own judgment — without reference. He takes everything cool and easy, and seemed thoroughly confident of the results. And so both the men, with their chums, worked away the day. all getting home well pleased, and feeling better for the outing, and ready for a good, enjoyable nighfs rest, as payment lor a day's toil. On the following fortnight, once more the " Pinholes " met ; all mustered in fair numbers, anxious to see the results. The four chums sat together. The owner of the exquisite lot seems to have downcast features. They compared results — without doubt he owns the worst work. How to account for it he does not know. Possibly, in the excitement, he mistook /-8 for /-32, and fogged all by over-exposure. His ideas had become confused by too many items of detail in his bound book. He got a bit mixed, while the man with the cast-iron slides had little incumbrance, and turned out the most successful pictures. It was therefore further resolved, before the close of the meeting, that the said four should once again take another outing, and carry as few articles of apparatus as possible, and, for certain, leave behind the bound volume of tables. Tom Coan. DERBY PHOTOGBAPHIC SOCIETY'S EXHIBITION. This Exhibition was held on January i. A local critic writes : — " The pictures hung numbered .H67, and included some of the finest amateur works which have ever been brought together in this or any other town. The specimens included a set of grand platinotypes by Mr. A. H. Bennett, which won the silver medal presented by Mr. W. Bemrose, J. P., as well as the series by Mr. F. E. Bemrose, which gained the bronze medal given by Dr. Kooney. Mr. J. Eiches' collection gained the certificate given by the Society and were also capital pictures well deserving the award. We might mention that the merits of tl-e exhibits were decided some time ago, the judge being Capt. Abney, the President of the Society. Mr. Councillor W. W. Winter exhibited a number of large photographs, which were very much admired, especially Ca'^^'ii ani Maiirjie. Mr. E. Keene had on view some excellent architectural studies, whilst leaving the professional pictures and coming to the amateur views Mr. E. C. Green's large collection were very deserving of notice. They were princi- pally land and sea-scapes and were highly finished works of an enchanting art. Mr. .1. Scotton's locomotives (silver print process) were highly meritorious, as all this gentleman's works are, whilst Mr. T. Scotton's views of interiors of Midland Eailway buildings, were admirable. Mr. J. Fhnt's On the Trent, as well as his photograph of the fountain in Derby Arboretum, were striking pictures, taken with car.\ and Mr. J. Eastwood's frame of eight included a magnificent portrayal of the interior of Lich- field Cathedral. Mr. F. G. Thurgood had some capital views hung, all well-known local scenes, and Mr. T. Scotton's picture, .-I Ileary Lihid, was another work which could not be passed without notice. The same gentleman had A view near liarut Green, which demanded attention. Next came some really excellent fruit by Mr. S. C. Ililey, with some high- class amateur work, by Mr. A. B. Hamilton, in the platkiotype ' A' pro- cess. One of these, which had been enlarged by Mr. Keene, is a portrait of Lieut-General Sir John Stokes, K.C.B. The same exhibitor has an amusing series of small works entitled Where are ijnii going to, my pretty Maid I Another fine picture is Honjleur. Viewi of Derbyshire are shown by Mr. C. H. Rourdin, and are very interesting indeed, both scenery, style, and effect being all that could be desired. The pictures which won the medals are specimens which speak for themselves, but Mr. Bennett's are undoubtedly the best. Mr. Riches' comes very near the winners, and his efforts well deserve the reward they obtained. All the other works are quite up to the average, and we must not omit to men- tion those of Mr. G. Walker and Mr. J. Fleet. On Wednesday evening the medals were awarded by his Worsliip the Mayor (Mr. Councillor W. H. Marsden), in the presence of a large number of ladies and gentle- men, including Messrs. R. Keene, T. Scotton (Hon. Sec. to the Society), J. Scotton, A. B. Hamilton, W. Wilkinson," Ac. WEST LONDON PHOTOGRAPHIC SOCIETY'S EXHIBITION. It is a pleasure to visit such an Exhibition as that of the West London Society, which was held at the School of Art, Bedford Park, Chiswick, on Tuesday and Wednesday last, as, from former experience, one may with tolerable certainty rely upon seeing a collection of high-class photo- graphs ably hung, and with the other details of an exhibition gratifyingly well managed. No small share of the undoubted success of this year's Exhibition may easily be traced to the efforts of the President (Mr. John A. Hodges), who, besides being a cultivated photographer, is also a working President (and therefore commendable to other [Photographic Society Presidents for imitation), taking an active part in the work of the Ex- hibition, and also contributing several of his own pictures thereto. About 180 frames of photographs were hung, the high average of merit displayed making it a trifle difficult for the critic to select individual works for praise, while happily there was little if any room for adverse comments, unless, maybe, the now inevitable opportunity at photo- graphic exhibitions for airing a preference for one of the two methods of focal treatment in vogue be taken advantage of. A capital exhibit was that of Mr, James J. Adam, his winter effects being so realistic as almost to cast one into a chill. For one of them, A Frozen Sii-amp, he was awarded the President's silver medal. A bronze medal went to Mr. L. C. Bennett for 7/1 tlie Fool, a study of craft below bridge, and the same gentleman showed studies of The Cnnch Digger, and The Cress Gatherer (a man gathering cress in an ordinary piece of land- scape, very cleverly treated to make quite an artistic picture). In Re- joining their Ship a boat laden with two or three figures is seen making for a distant vessel, but, to complete, or rather to tell, the intended story, Mr. Bennett might have made an attempt to show us the faces of the sailors, and could well have afforded to have been a trifle less fuzzy. Mr. W. A. Brown showed an excellent rendering of The Brook, a water-cum- tree bit which the late Lord Tennyson might conceivably have had in his mind when writing the poem. An untouched, out-of-door Portrait of a Lady, by Miss Brigg, showed soft lighting, and ease of pose, and in On the Basingstoke Canal Mr. W. L. Colls was represented by a tender and harmonious view. Mr. S. T. Chang merits our congratulations for his continued improvement, his Holland House interiors. Cottage near Witley and Church near Godalming, showing care in the treatment. The President (Mr. Hodges) received a bronze medal for Drear December, a large study of a bit of desolate landscape with trees, which, to our thinking, would have been more effective had a cold instead of a slight sepia tone been employed. Anyhow, the same gentleman's Welsh series. Shallow fVaters, In Conway Vale, and the other pictures of his which we have noticed before, are, to our thinking, as good as anything he has ever shown, and much superior in handling and effect to the picture here medalled. Mr. George Lamley, a painstaking artist, showed several, including A Sluggisli Birer (a charming study previously noticed), and received a bronze medal for a study of trees and loneliness — Solitude. Mr. W. S. Rogers' small picture of craft. Coaling — Tyneside, and his roadside view. The King's Highway, were full of delicate detail, and deserve high praise, as did Sir. H. R. Bainger's small study of Richmond Bridge. Mr. Rogers' delicacy of treatment pleased us very much. He received a bronze medal for The Year is Dead, a bleak view of leafless trees. By the way, a distinct vein of pensive melancholy ran through the Exhibi- tion, in which there were any number of frost studies, twilights, deserted mills, departing days, winters, et hoc. Mr. A. W. Soanlan, with The Return of the Herring Fleet, a large, breezy study of sea and craft, having a pleasant, warm tone, and an admirable view. Haymaking, Messrs. H. and L. Selby, and Mr. T. Tripplin (vigorously rendered, if rather heavy- shadowed, Norwegian views), all showed good work. Mr. C. E. Whiting's bustling, boldly- handled views of Seddon Harbour, Plymouth, were very fine in technique, but possibly would have looked better in a less bilious tone. Mr. Charles Winter deservedly gained a medal for a capital outdoor untouched por- 26 THE BRITISH JOURNAL OF PHOTOGRAPHY. [January 13, 1893 trait of M'l Mother, and showed several winter views of great merit. We liked a little view of Sprhifi by Mr. George Way, a sharp, crisp study, as spring effects should be. Two interior views of Hampstead Parish Church, by Mr. A. A. Boucher, were, perhaps, the best interior work shown, and one of them gained a medal. _ As we have already said, we have nothing but praise for the Exhibition as a whole, which may in some degree account for the fact that we have been able to find so few faults with individual pictures. A happy feature of the display was the inclusion among the exhibits of a collection of photographs medalled at previous exhibitions of the Society. The Judges were Messrs. A. Horsley Hinton and J. C. DoUman, B.I., from whose report we cannot help making the following extract, which may be of interest at the present juncture :— " The Judges wish it to be distinctly understood that they do not consider the entries in the Outing Class are any of them deserving the distinction of a medal, but, as they are asked to award a silver medal, they consider Near Weyhrklge, by Mr. L. Selby, the best of the class. They would like to add that they only award this medal feeling themselves bound by the printed conditions, which leave them no option but to award a medal to work which they consider de- serving or otherwise." ♦ — ©ur IBtiitorial JTatle. Handbook of Rbgulations and Genkbal Infobmation segabdino the chicago exhibition. Thik handbook contains an important mass of well-arranged informa- tion relating to the World's Fair, and certainly ought to be in the hands of every one who feels at all interested in it. Among the drawings are a bird's-eye view of the Exhibition, and a view of the principal buildings devoted to special departments. The tables showing the M'KLnley Tariff rates are significant, as showing the heavy duties to which articles imported into the United States are subject. This handbook is issued from the offices of the Royal Commission, Society of Arts, John-street, Adelphi, London, and all communications must be addressed to the Secretary. RECENT PATENTS. APPLICATIONS FOR PATENTS. No. 23,315. — " Improvements in or reLiting to Packs or Series of Sheets with Notched Riges, more particularly applicable to Packs of the Flexible Sensi- tised Films in Photographic Usage." Complete specification. J. T. Clark. — Dated December 19, 1892. No. 23,378. — "Improvements in or connected with Doublet Lenses for Photo- graphic Purposes." C. P. Goebz and E. von B.osoa.~ Dated December 19, 1862. No. 23,434. — "Improved Photographic Dark Slides." S. H. Bbittain and E. J. Brittaiu. —Z»a-chest«r Oxvc.bn (Bris's Patent) CoMr.\xy, Ltd., and W. M. J Acnsos.— Dated December 20, 1892. No. 23,856 -"An Improved Metliod of Attachinethe Legs of Camera Stands to the Tops.' W. 0. Twiedv.- iia/cd Dcceinber 27, 1892° No 23,926.— "Improvements in Panoramic Cameras." R. W. Stewart — Dated December 2^, i9li% . »*«."aki. No. 23,942.—" Magnesium Arc Light for Photography." G. W. MORGAN.— Dated December 28, 1892. No. 23,944. — " Improvements in Photographic Cameras." A. C. Smith and A. A. Smith.— Oaterf December 28, 1892. No. 23,987.—" An Adjustable Clip or Grip for Holding Photogr.iphs. A Vig- netting Chair and a Stand or Support for a Screen or Background Frame used in and for Photographic Purposes." H. L. Uorkl.— Dated December 29, 1892. No. 24,106.— "Improvements in Photographic Apparatus." S.D. Williams. —Dated December 31, 1892. No. 6.— "Improvements in Lanterns and Other Means for Illuminating Photographic Dark Rooms. G. V. Fosbery.— Z)a/«rf January 2, 1893. No. 202.—" Improvements in Portable or Hand Photographic Appar.itus or Cameras. " Communicated by J. B. Brunei and A. Reynier. W. P. Thomp- son.— Dated January 4, 1893. No. 312.— " Improvements in or Relating to Photographic Cameras." H B. Sharp and H. C. Hitchmouoh.— Oa^sd January 6, 1893. SPECIFICATIONS PUBLISHED. 1892. No. 1635.—" Magic Lantern Slide Carrier." Contbkari. No. 2852.—" Photographic Cameras." HuQHls. No. 2879.—" Photographic Cameras." Cricks * Taylor. No. 3226.—" Lock for Folding Camera Tripod Stands." BiRNlE. No. 4498.—" Developing Photographic Images." Hauff. No. 18,836.—" Burners for Lime Light." Anderson & Wrench. No. 18,919.—" Lenses for Telescopes," &c. GcxN. PATENTS COMPLETED. An I.MPROVEMENT IN CARRIERS USED FOR HOLDINQ SLIDES IN MaOIC Lanterns. No. 1635. Henry Grant Madan Conybeare, The Hut, Ingatestone, Essex December 3, 1892. My invention relates to improvements in lantern-slide carriers, such as those used for holding slides in optical or magic lantenis, .ind has for its object the provision of means whereby the lantern slides may be ejected from the carrier, automatically by, and simultaneously with, the movement of slide within its frame, in its operation from side to side, thus greatly facilitating the manipu- lation of the said slides when changing, and obviating the necessity of handling the .slides so that the fingers come in contact with the faces of the slide, and thus soil them. My invention is essentially an improvement of tlie invention described in Letters Patent No. 20,972, and d.ited December 23, 1890, and consists in the application to such a sliding carrier of means for the automatic operation of the ejecting lever by tlie sliding movement of the carrier. In carrying out my invention I provide a carrier, into which the lantern slides ara inserted through openings at the toi) of the frames. This slide- carrier is adapted to slide in .i suitable frame. I pivot a lifting lever on each side to serve the two slide .spaces. The back end of each lever is operated by a pusher-rod. The under side of the top part of the frame is recessed along its centre portion, such recess terminating at each end by an inclined plane, agains which the end of the pusher-rods can engage. The recess is made deep enough to allow the pu.sher-rod3 to move high enough for the end of the lever to occupy the lowest position when the lantern slide is resting in proper position in the frame for projection. When, now, the slide-carrier is moved tow.ird one end of the frame, so that one of the openings in the carrier, with its slide, corresponds with the opening in the frame, the inclined plane at one end of the recess in the upper part of the frame engages the end of the pusher-rod, depresses the shorter end, raises the longer end of the lever, and lifts the slide into such a position as to allow of being taken liold of by the hand for removal from the carrier, upon which a new slide can be inserted. The carrier can then be slid along so as to register the new slide in position, and the slide previously being shown is ejected partially from its position at the other end of the slide-carrier. A suitable recess may be formed in the lower portion of the frame to allow room for the movement of the levers if thought desirable. What is claimed is : — 1. In a lantem-slide carrier, a sliding frame having levers pivoted thereon in combination with means for the operation of the said levers during, and by the sliding movement of, the slide- carrier. 2 In such a l.antern-slide carrier, a pivoted lifting lever in combination with an inclined jilane, upon the frame in which the slide-carrier moves, and adapted to engage with the said lever to effect the lifting of the lantern slide, substanti.ally as described, ImPBOVEMENTS in OB RELATING TO PHOTOGRAPHIC CAMERAS. No. 2852. Griffith David Hughes, Cheadle Hulme, Chester. December 3, 1892. This invention relates to apparatus I have designed for photographic cameras for holding a number of prepared plates to receive the negatives, one of whicli will be presented at a time to receive the picture. It consists essentially in the combination with the apparatus of a rotating holder or carrier, comprising a number of sheaths, or receptacles, or slides, in which the photograph, prepared plate, or other object can be placed, a spring barrel or other motor by which tliese are rotated, and a catch or clip, which will release one of the sheaths oi receptacles at a time whilst retaining or pre- venting a forward movement of the others. In carrying out the invention in a suitable position, in the casing which surrounds or contains the apparatus I aifix a spring barrel, or other rotating Jftouary IS, 1803] THE BRITISH JOURNAL OF rilOTOGRAPIlY. 27 tnechtnism, capable, when set, of a continuous movement for several revo- lutionc Affixed to, or carriee rotated round tlie centre of the drum. The sheaths, slides, or receptacles which carry the object are preferably loose on the spring barrel, and free to move about the barrel centre inde- pendently of any movement of the sjirine barrel. In addition to these, the barrel carries a projecting finger or catch, which conies in contact with, or engages with, the receptacles or objects, and carries them round. A sprini! catch or other clip is nllixed to the frame to retjvin the object or j.late at the desired position to yield the image or receive the impression, and which, when moved, will release one at a time, which then drops forwartemAer 3, ISg'i. This invention relates to an improved construction of lenses for telescopes, photographic cameras, and magic lanterns, and has for its object to proviile a lens whic'li will be less exjicnsive than the ordinary solid lens, the invention being more particularly applicable to lenses of large size. In carrying out my invention, I construct a hollow case, as hereinafter de- scribed, in the form of a lens but hollow, and made mainly of gla-ss or other transparent material, hereinafter referrcl to as glass. Within this case or hollow lens is placed water or other clear liquid, the whole forming a complete lens. Tlie lens is formed by two plates of the trans- parent substance, one or both of which is or are curved in the desired manner, and the two are connected together by a metal or other tubular case. According to one arrangement there is an annuhar projecting part around the interior for each glass, against which the edge of the glass rests, being fixed by cement. This annular part Hay be formed by turning in a lathe, or by forming a channel in the case at the required parts. Instead of fixing with cement a cap may be employed, screwed on to or into the tube, and fitting closely around the edge of the glass, and pressing it .against the annular jirojection. With this arrangement the lens can be reailily taken to pieces and fresh glasses put in. Indiarubber or other soft material must be placed Vietween the ledge and the glass in order to render it less liable to get broken. A simpler form, in which the parts are not detachable, consists in making the ends of the tub3 slightly thinner, forming a ledge against whicli the glass would rest, the ends being then turned over on the glass, fixing it in place. In order that the liquid may be admitted, a hole is formed in the case, or, in some cases, in the glass itself, closed by a cap or other suitable means, or, when the opening is in the gh».s.s, by sealing it after the liquid has been inserted. The tubular case into wliich the glasses are fitted may be made in two jiarts, one screwing over the other or sliding over it, the two "fitting tightly together in order that the thickness of the lens may be regulated to any desired amount. The lens is preferably filled with liquid at a rather high temperature, higher than it is likely to reach when in use, so that on cooling a slight space is left with vacuum to allow tor any expansion that may occur. This will not interfere in any way with its use, as the sides of a lens are never used, and the tube or aperture used for filling may be made sufficiently large to serve for the empty space. A lens may also be formed with a cell wholly of glass, the two parts being formed with rims, or cylindrical sides, which are placed together, and joined by a band of glass or suitable material, liquid being inserted as before. In order to form the glasses for the lens, I may blow a hollow sphjre in a mould or box of the required form, manipulating the mould in the manner well known to glass-blowers, in order to get an even surface and thickness. 1 afterwards, with a cutting instrument, cut the sphere into parts of the required diameter, the size of the sphere regulating the curvature of the lens, so that a regular and known curvature is always obtained. According to another arrangement the glasses are moulded or pressed into shape. When used in photographic cameras the usual stops .are employed in front of or between the lenses to reduce the liglit and give the required clear- ness of image. [Probably the patentee was not aware that Archer's fluid lenses, Sutton's panoramic and cylindrical lenses, and some others were con- structed on this principle. — Ed.] I.MrnOVE.MESTS IN PHOTOGRArHIC LENSES. No. 21,933. Thomas Rudolph Dallmeyer, 25, Newman-street, Middlesex.— December 10, 1892. My invention relates to a lens for the pro focus as compared with the anterior positive lens. This negative element is » double combination, and is corrected for both actinic and spherical aberration. The annexed drawing at figure 1 shows a combination in accordance with my invention. The anterior positive element represented in this figure is a well-known jjortrait lens : it is in four p.arts. a' a- a* and a*, and of these the hindermost, marked a*, can be screwed out a short distance. The focal length of the com- bination is 8i inches, and its aperture 2^ inches. The negative element is in four pai-ts, h' i- 6^ h*, which constitute a symmetrical double combination, i' and h* are similar, and so also Ifl and b*. One of the pairs is shown separately and in full size in figure 2. The parts 4' and h* are of hard crown glass (refractive index 1-5179), and Ifi and A" are of heavy tliiit (refractive index 1-6202). The anterior surface of *' is convex, and the radius of curva- ture is 4-396 inches. The posterior surface of 6' is concave, and the radius of curvature is 0-9 inches. The anterior surface of (fl has the same curvature, and is cemented to the posterior surface of i'. The posterior surface of i- has a curyatnre of 1 -375 inches. There is an .air space between the surfaces of 6^ and '■', and'these surfaces may be separated by a considerable interval, but the study which I have nuule of the subject since the date of my application . leads me now to pr»fer that b- and Ifi should be nearly in contact at tlieir edges 28 THE BRITISH JOURNAL OF PHOTOGRAPHY. [January 13, 1893 The negative focal length of the element J' J^ i^ J* is 2 inches, and it is so mounted that by a rack and pinion the distance between it and the anterior element can be varied. The correction of this negative element is such that it is complete for an object 12 feet in front of the camera focussed at a distance of 12 inches. When any deviation is made from these positions there is a resulting aberration in the combination, which can be corrfcted by screwing ont the lens a* a short distance. The measurements which I have given above admit of variation. For the positive element any (preferably large aperture and short focus) photographic objective may be employed, but it is e.\pedient that it should admit of the spherical correction being varied. The negative element is in all cases to be a donble combination corrected for actinism and spherical aberration ; it is to be convex on its anterior and posterior faces and its focal length is to be less than that of the positive element. The negative element may be construoted as indicated in fig. 1 of the drawings accompanying my provisional specification, the heavy flint glass being external in place of internal, but the arrangement above described is that which I prefer. In the use in the camera of the instrument represented by fig. 1, the focussing glass is first set at any distance from the posterior face of the nega- tive element, according to the amount of the magnification it is desired to obtain. Then the focussing is eft'ected by moving the positive anterior element to or from the negative posterior element by means of the rack work provided for the purpose. Finally, the sharpness desired is given to the focus by \in- screwing the posterior lens a'' of the anterior element to the necessary extent. Having now particularly described and ascertained the nature of my said invention, and in what manner the same is to be performed, I declare that what I claim is : — A photographic lens for the production of large primary images, and consisting of an anterior positive element and a posterior negative element, the latter a double combination convex on its anterior and posterior faces, corrected fpr actinism as well as for spherical aberration, and of shorter focal length than the anterior positive element. iHeettngd of Soct>tt>iS» MEETINGS OF SOCIETIES FOR NEXT WEEK. Date of Heetlng. January 16 16 16 16 16 16 16 ..„ 16 17 17 17 17 17 17 17 17 18 18 18 18 18 18 19 19 19 19 19 19 19 19 20 20 20 20 20 21 Name of Society. Camera Club Dundee Amateur Fillebrook AthenlBUm Glasgow & West of Scotland Am. Hastiiifrs and St. Leonards Leeds Photo. Society Richmond Soath London Birmin|;fbam Photo. Society ... Brixton and Glapham Eieter Hackney Keighley and District North London Paisley Rochester Brechin Bnry Manchester Camera Olab Photographic Club Sontbport South&ca Birmingham Photo. Society ... Camera Club Glossop Dale Greenock Hall London and Provincial Oldham Oxford Photo. Socio^ Cardiff Croydon Uieroscopical Holborn Leamington Maidstone Hnll Place of Meeting. Charing Cross-road, W-C. Asso. Stndio, Nethergate, Dundee. Fillebrook Lecture Hall. 180, West Regent-street, Glasgow. Mechanics* Institute, Leeds. Greyhound Hotel, Richmond. Hanover Hall, Hanover-park, S.E, Clnb Room, Colonnade Hotel. 37*>, Colfiharbour-lane, Brixton. City Chamherrf, Gandy-st., Exeter. 206, Mare-street, Hackney. Mechanics' Institute, North.street. Wellington Hall, IsUngton, N. 9, Gauze-street, Paisley. Mathematical School, Rochester, 14, St. Mary-street, Brechin. Club Rooms, 13, Apar-strcet, Bnry. Victoria Hotel, Manchester. Anderton's Hotel.FIeet-street.E.O. The Studio, 15, Cambridge-arcade, 3, King's-road, Southsea. Clnb Room, Colonnade Hotel. Charing Cross-road, W.C. Mnsenm, Kelly.street, Greenock. 71, Prospect-street, Hull. Champion Hotel, 15, Aldersgato-st. The Lyceum, Union-st., Oldham. Society's Rooms, l:j6. High-street, Public Hall,George-street, Croydon Trinity Church Room, Morton-st. " The Palace," Maidstone. 71, Prospect-strcet, Hull. PHOTOGRAPHIC SOCIETY OF GREAT BRITAIN. January 10,— Mr. T. Sebastian Davis (Vice-President) in the chair. Mr. H Wilmer was elected a member. The Chairman announced that the Lincoln Camera Club had been admitted to alliliation of the Society, and that the annual dinner of tlie Societv would be held ou Febniary 13 next. The Chairman also stated that Mr. William Bedford was critically ill. Auditors .and scrutineers were appointed for the forthcoming annual meeting on February 14. Experiments WITH two New Developers. In the absence through illness of Mr. J. Spiller, his paper on the above sub- ject was read by his daughter, Miss Spiller, who brougiit a number of nega- tives developed with both amidol and nietol, samples of which were shown. With regard to amidol, Mr. Spiller said that, from experimeuts made at various times during the past six mouths, he was incliueil to think that it is best to weigh out a certain number of charges, and keep these separate lots of amidol in dry glass tubes, dissolving them up, one at a time, iu a nearly saturated solution of sulphite of soda to prepare a concentrated develojjer, which then only requires dilution for use. For professional practice the mixed developer, especially if concentrated, will keep in good working order long enough to justify the preparation of a stock solution. For this take Water 7 ounces. Sodium sulphite cryst 14 ,, Amidol 60"grains, Mix, as required for use, with about three times its bulk of water and a trace of bromide, or none, according to circumstances. It is possible to make the same dose of amiilol do duty for two or three plates in succession, and then to fortify it and go on again, but it is better to exhaust it entirely, either by adding weak aliiali — dilute ammonift, carbonate of soda, or borax^and then throw it away. For over-exposure, a weak developer and free use of bromide is the best treatment, and for the opposite case, or even for building up extra intensity in normal exposures, use a stronger solution with an increased pro- portion of sulphite, if the alkaline method is not resorted to. As a rule the image should appear in eight or ten seconds, and be fully developed in about four minutes. The negatives are of a coaly black or pencil-lead colour, more like ferrous-oxalate than jiyrogallic deposits, and print quickly. As a consequence it i.s necessary to carry forw.-ird the development to a stage beyoud what is ordinarily required in brown negatives. Hence an impression is given that the silver image loses by immersion in the fixing bath, which he does not think is actually the case, " Metol " is the other new developer refeired to in the heading, and with this also he had iiiade a good many experiments. Dr. Eder speaks of it in the highest terms of approval, and predicts that it will speedily depose all other known developers. Dr. Stolze and Dr. Just report well of it, and for many reasons he (Mr. Spiller) feels inclined to agree with them, mainly because metol is so remarkably permanent even in solution, and certainly superior to amidol in this respect. Ou a recent occasion he developed a few plates with a stock of developer prepared last June. The deposit is of the neutral grey colour and free from stains, and can easily be worked up to any required degree of density. Dr. Eder's formula stands thus :— Solution A. Water 1000 parts. Metol 10 „ Sodium sulphite cryst 100 ,, Solution A. Water •. 1000 ,, Sodium carbonate cryst 100 ,, Mix in equal proportions, or less of the soda and more water, according to requirements. For landscapes a more dilute solution is prescribed tliau for studio work, but the printeonate ; but, as it was so weak, it only displaied the carbonic acid with difficulty, hence commercial sulphites usually luutained alkali, so tliat a developer of .amidol ami sulphite cont.iined an unknown quantity of sodium carbonate. It had been suggested, however, that it was desirable to make a developer of known constitution, and that could be done by the iise of potassium metal)isulphite, which was made by a patented process of supersaturation with sulphurous acid. There was thus a certain amount of free sulphurous acid present, wliich acted as a restrainer, and, although a mixture ol^ amidol and metabisulphite would not develop by itself, it was well preserved. Tlie same proportion as sulphite, down to equal jiarts, of metabisulphite to amidol answered well. Nothing could be more convenient to use than the formula given by Mr. Dresser, and he advised start- ing with a strong solution of developer, and trusting to extra quantities of bromide. The less time the plate was in the developer the better and cleaner the results. Amidol for negative work was as like pyroasit could be, althougli more energetic. Any one accustomed to use pyro couUl easily substitute amidol for it, and when it changed colour it did not deposit like jiyro, the colouration being soluble throughout. It remained clear for hours without staining the film, and would answer well for dipping-bath development. A Chemic.vl Study of Mkrcueial Inten-sikication. Mr. H. Chapsian Jones read a paper treating of the chemistry of the various forms of mercurial intensification. [Tliis will be given m «'toi«o in a future number.] He eoneluded by recommending the use of mercuric chloride followeil by ferrous oxalate, as advised by him in January, 1890. Speaking of the elimination of hypo from the film, he advised the use of an acidified alum biith for the purpose, as it was practically impossiMe to remove it by simple washing, which would always leave enough to spoil many methods of intensification. .Mr. W. E. Debenham said it was a very useful thing to have a definite account of the chemistry of mercurial intensitication, but he regretted Mr. Chapman Jone-s had not extended his studies so as to include intensifi- cation with iodide of mercury and Schlippe's salt — a method which he (Mr. Debenhani) preferred to all others. With several methods the image was changed by light ; and with tlie cyanide method there was an alteration of the density ratios, unless hydrochloric acid was added to the mercury. Mr. Arnold Spiller said some time ago that with iodide of mercury no combination with the gelatine took place, so that the addition of liydrochloric acid was not necessary. Much greater increased density was obtainable witli it than with ordinary methods of intensification. After the treatment with Sclilippe's salt the ima^e appeared to be thoroughly permanent. It was .sometimes said that the method stained, and caused a deposit in the clear glass, but that was the case with all methods if tlie plate were not thoroughly fixed and washed, in which case it was not the hypo alone in the film that was objectionable. Photographers generally did not employ perfectly new fixing baths, so that a certain amount of silver was likely to be left in the film. Mr. Debenhani showed a plate one half of wliicli was clear glass and the other half a negative which had been intensified with mercury, iodide, and SchUpi)e's salt, and drew attention to the clear half, which was free from deposit. Mr. Chapman Jones, in reply, said he always fought shy of iodides and sulphides in intensification, as he found iodide intensifiers unreliable. A drawback to the use of Hchlippe's salt was that, if it produced a thoroi;gh change on the image, nothing could be done with it afterwards, as it left a series of compounds wliich were awkward to attack. By his plan nothing but metallic mercury and metallic silver was added to the image, and they could do anything with it. Gaiacoi. The Hon. Secretary gave a brief precis of a paper sent by Colonel J. Water- house, in which the author confirmed the experience of Messrs. A. & L. Lumiere (see '• Continental Notes and News "), establishing the fact that the developing properties of gaiacol were due to its impurities. The author al.so stated that old carbolic acid had cleveloping action, whereas new carbolic acid had not. LONDON AND PROVINCIAL PHOTOGRAPHIC ASSOCIATION. January 5, — Mr. A. Haddon in the chair. Mr. P. Everitt exliibited a jihotograph taken in a Skaife's pistolgraph. Mr. H. Snowden Ward sliowed examples of gelatino-cldoride printing by Mr. Hanna, of Auckland, New Zealand, who had sent them to this country to learn the opinions of English photogr.aphers as to their quality. They were considered excellent by the meeting. The Hon. Secretary drew attention to an article on " Spirit Photography " in the Forinii/htlu Review by the Rev. H. R. Haweis, quoting the passage relating to the young lady who w.as alleged to have iliscovered the face of her deceased lover on a " blurred " plate. Mr. Dbaoe said Mr. Haweis' contention was this : " May not a surface more chemically sensitive than the human retina be able to receive impressions of things which to us are invisible ?" The Ch.virman having recommended photographers to in future examine " blurred negatives " before rejecting thein, tlie subject dropped. PRiNTiNfi-ouT Opals and Lantern Slides. Mr. W. E. WoODBDRT ilemonstrated the Paget Company's new printing-out opals and lantern slides, saying that their manipulation was practically the same as "ehitino-chloride jirinting paper, they being coated with an emulsion of that character. In printing, as sharpness was so desirable, it was necessary to print in the sun, and always to keep the frame in one direction ; otherwise, If it were turned another way, probably a double imago would result. He exhibite THE PHOTOGRAPHIC SOCIETY. To the Editor. Sir, — I shall be much obliged to you if yon will allow me space to inform the members of the Photographic Society of Great Britain that the figures opposite the names of Mr. Traill Taylor and Prof. J. M. Thomson, in the table at page 90 of our Jours.\l, have been accidentally reversed, and that Mr. Traill Taylor should have had six instead of two attendances credited to him. I would also remind our members that nominations for the new officers and council should be sent in without delay, the 24th of this month being the last day upon which they can be received. — I am, yours, itc, Chapm.an Jones, Hon. Secretary, Photographic Society of Great Britain, 50 Great Russell-street, W.C, January 6, 1893. THE LOUTH EXHIBITION. To the Editor. Sir, — I herewith enclose you Circular of Invitation for our third annual exhibition. I think we are the only Society that run an absolutely free to the public exhibition, without tickets of admission or some other check to the influx of the masses. That it is appreciated by the people is clearly shown by the numbers visiting. The first year about 500 passed through during the five hours it was open. Last year, in the same space of time, 1000, out of a population of 10,000, availed themselves of the opportunity of seeing work by such workers as Messrs. Gale, Ralph Robinson, Bhedwar, P. Lange, Cyril S. Cobb, F. Sntcliffe, B. G. Wilkinson, Chamberlain, Wade, L. Meldon, Edgar Lea, Court Cole, Armatage, Smart, Wright, Pearson, &c. This year we go in for two days, and hope to have even a greater success, as we fully expect to secure the kind support of many of the foremost workers of the present day. — I am, yours, lic, S. Fhakcis Clarke, L.D.S., Hon. Sec. Louth and District Photographic Society. Vpgate, Louth, January 6, 1893. A CORRECTION. To the Editor. Sir, — Permit me to call your attention to the fact that your report of the recent proceedings at Bloomsbury Hall is open to misconstruction, not only on account of the phraseology used, but for direct statements as to facts. January 13, 1893] THE BRITISH JOURNAL OF I'llOTOGRAPTlY. 31 The cloBiDg parivgraphs of the report are especially unfortunate for me, as I am there reported as speaking of Mr. Eastman as my " assistant " — obviously an impossible relationship. I am sure that you, together with no small number of the 30O persons present at that time, will not fail to remember that, in my impromptu response to the address, I very particularly and specifically pointed out that Mr. Bider had given me far more credit than I was entitled to in connexion with any of the inventions owned by the Eastman Comptmies, and that in no sense could I be considered as entitled to any credit, excepting as co-inventor with Mr. Eastman of some of the earlier inventions. I also at that time expressed most earnestly the hope that no mis- conception of the facts should become current, especially through the medium of the press. As it is well known, I have been a resident of London continuously during the past seven years, and it is, therefore, obvious that my asso- ciation with Mr. Eastman as co-inventor must have been limited to a very few of the earlier inventions, and this fact will be further borne out by reference to the titles of all the patents taken out for many years past. — I am, yours, &o., W. H. Walker. London, W., January 9, 1803. [Mr. Walker is quite correct. He certainly emphasised the part taken by Mr. George Eastman in the various schemes and inventions of the Company, and disclaimed his own sole action in such matters. Our report, instead of saying,' " aesUted by Mr. Eastman," should have read— Mr. Walker, in conjunction ivith Mr. Eastman, which would correctly have expressed the tenour of Mr. Walker's remarks relative to this.— Ed.] <■ HALATION AND DOUBLE FILMS." To the Editob. Sib, — In reply to the opening remarks of Mr. W. B. Bolton in his "Note on Halation and Double Films" in your issue of the 6th inst., I should like to say that I think he must have somewhat misread my paper on " Multiple Coated Plates," to gather from it, or even continuing on the lines indicated, to conclude that it is impossible to produce a negative with clear shadows on a " Sandell " plate. I cannot find that I said, and I certainly did not intend to say, anything leading to such a supposition — in fact, quite to the contrary, I distinctly stated that if the correct exposure were given — that is, a full exposure for the shadows — then, so far as they were concerned, only the top film was used, and in its action differed nothing from that of an ordinary plate. This being the case, there is no reason why the shadows should be rendered less clearly, or, indeed, in any way differently than by any one filmed plate. And even where sufficient exposure has been given to affect the lower film in the shadows, the upper can be reduced till the desired amount of clearness has been obtained. As to the historical inaccuracy that Tdr. Bolton accuses me of, I will only say, without either admitting or denying the accusation, that had I, at the time of writing, had any idea that the article would be published, I should have assured myself of the absolute accuracy of any such state- ment, instead of trusting to the information of one whose authority on such matters I have never yet had occasion to doubt, for my own limited experience carries me back far short of the dates mentioned. I may draw attention to the fact that I did not say that Captain Abney was the first to discover or notice the causes of halation, my idea being rather that he collected the various suppositions that had been put forward, and by the aid of his own experiments, formulated them into a definite theory. If I am vrrong in taking this view of the case, I shall only be too pleased to be put right. With regard to the chromate of silver question, on which Mr. Bolton lays so much stress, I must still hold that Mr. W. K. Burton made something considerably more than a suggestion, though, perhaps, the less I say on this subject the better, for it verges on a question of priority, which has already been the subject of no little dispute, yet some light may be thrown on the matter by reference to a letter of Mr. Burton's which appeared in I'hutography , No. 208, page 702, and to his article in the The British Journal Almanac for 1888, therein alluded to. In conclusion, I will only say that perhaps few have read with greater interest Mr. Bolton's remarks on the dual action of chromate of silver than yours truly, Gheoob Grant. The Tower House, Bexley Heath, January 9, 1893. A VALUATION WANTED. To the Editor. Sib, — Would you give us your opinion as to the approximate value of goodwill and negatives of our business ? The particulars are as follows : Business established eighteen years ; business done this year, 850/. ; profit, about 3.50/. to 400/. ; number of negatives, about 70,000 ; size of town, 13,000, wiih good district, very little opposition (one very cheap man) besides ourselves ; prices obtained as per list ; eighty per cent, of business done is for cash. The rent is 30{. a year ; taxes very moderate. Position of premises good, with ample accommodation. — I am, years, Ac, January 9, 1893 Seasidb PnoTOOBAPBEB, S Possibly some of our friends who have had experience in the uation of photographers' businesses may be able to furnish an opinion. — Ed.] ^Instoew to (fforrcgpontjcnts. A. MciRHEAD. — We can add nothing to the information we have already given. Jno. W. Spbnceb. — Since the date you name we believe that the firm in question has failed. J. H. B. compl.iins of a dishonest canvasser. Such a matter had better be referred to the police authorities. F. C. Green (Chihuahua, Mexico) Messrs. Hnrter & DrifBeld have no doubt already sent you a copy of their pamphlet. J. L. L. — We have had no oiiportunity of practically testing the apparatus but it is well spoken of in the American press. John T. French. — Thanhs for your letter relating to the South London Photographic Society's Exhibition, but we do not propose to reopen the controversy. John Macallan. — ^The fault at first sight seems to be in the plates, but we cannot, except in one isolated case, discover any nucleus which would account for the tran.sparent spots. D. AvANZO (Antwerp). — The article by Mr. J. T. Hackett on " How to Make a Camera Bellows " appeared in the Almanac for 1876. This answers several other correspondents who have addressed a similar q\iestion to us. Cymro Bach. — The precise distance at wliich the back elements of your cabinet portrait lens should be apart must be determined by experiment. If you make a ring a quarter of an inch wide, it will be found to be. about the correct distance. A. McDonald. — The subject has several times been referred to. Coal gas compressed in cylinders undergoes deterioration by keeping. Your experi- ence is by no means exceptional. It will quite account for the batch of enlargements all turning out under-exposed. J. W. C. — The bronze powder, with which the mounts are printed, is probjbly the cause of the spots. If the maker of the mounts cautioneii you against what might happen, you have no cause of complaint. If you brought au action — even if you could prove the mounts were the cause of the spots— yoa ' would certainly lose it. A. W. CURTISS. — If when using a single lens the illumination falls off seriously at the margins when a very small stop is used, remove the ground glass, place your eye at the side, and see whether the whole of the light from the lens reaches the side in an unobstructed manner. If it does not, let the distance between it and the lens be decreased. W. A. B. — The yellow patches on the prints arise from imnerfect fixation. Cold weather may have had something to do with it. When the fixing solution is very cold, a considerably longer time should be allowed for its action. Some of the prints have apparently been allowed to stick together, so that the solution has not had free action. The cause being pointed out, the remedy is obvious. A Lancashire Lad. — So far as we have been able to learn, the princijia towns in Australia are well stocked witli photographers, and in most of them, if not all, competition is as keen there, both as regards quality of work and prices, as it is here. Probably, if you were to write to the Secre- tary of the Photographers' Benevolent Association, he might be able to give you more definite information. W. .V. P. and W. Benn ask for directions for making lantern slides by the wet-collodion process with a copying camera. — It is impossible in the limited space of this column to give any instructions that would be of service. Our correspondents should procure one of the several cheap manuals of photo- graphy published, say, twenty years ago. They all give full working instruc- tions, and what is said on the process generally applies equally well to the making of lantern slides. Thos. Carter. — See a leading article on the subject in the current number. We do not know the exact cost of a prism of the size mentioned, but it would certainly be many times that of a mirror. With ordinary care, a mirror will last a long time without requiring to be resilvered, though it may require to be repolished occasionally. To retain the instrument in good condition, it should be kept in a dry place, and protected as much as possible firom the atmosphere when out of use. H. H. Holden. — 1. We cannot estimate the value of the gas-bags. But it would certainly be very little, even if they are in good condition, which i» very doubtful. As they were the property of a travelling theatrical com- pany, they are probably of incoveniently large size. Cylinders have quite superseded bags. 2. If the prints sent are the best the negatives will yield OQ albumen paper, they will not do at all, for platinotype bromide paper will .suit them best. 3. It will certainly answer your purpose best to purchase the tissue ready sensitised. 4. There is little doubt that the picture ij copy- right. Tlie publisher will, we imagine, help you, or, at least, give you some information as to the photoeugraver. 32 THE BRITISH JOURNAL OF PHOTOGRAPHY. [Januarj- 13, 1893 W. F. R. — Stereoscopic pictures may be taken quite well by mounting a small longitudinal table on the stand, and sliding the camera against checks at each end in succession. If the object to be taken be, say, over eight or ten feet away, then may these checks be parallel to each other ; but, if it be close at hand, such as a vase of flowers within a few feet of the camera, then will it be well that the checks converge sufficiently to ensure the subject being in, or nearly so, the centre of the plate. ■C. Williams .«ays : " Last week I poured some boiling water into a very large porcelain dish to warm it before commencing to tone a batch of prints, and It cracked, and has since come in half. Can you tell me of any cement that will mend it for toning, fixing, and washing, hot water being sometimes used?" — We know of no cement that will fulfil these conditions. During very cold weather hot water should not be suddenly put into earthen dishes, or the result will be similar to that described. A CoKHKSPOXBENT, writing in reference to "F. E. G.'s" query as to sulphur on negatives last week, suggests that the sulphur may possibly be dissolved out by a solution of sodium sulphite. The same gentleman also raises a protest against Mr. A. R. Dresser s recommendation in a recent developing formula to employ saturated solutions of the alkalies. If our friend will turn to our rei>ort of the meeting of the Photographic Society of Great Britain on Tuesday, he will see that Mr. Dresser now advises solutions of a definite strength. Xeso says : " I was shown some prints by one of my customers which were said to he platinotypes, but, from the price paid for them, and the time in which they were produced, I believe they are bromides. My competitor in this town, I am told by one of his lateempJoySs, regularly sends out bromides printed at night for platinums. Is there any ready test that will for certain detect this fraud ?" — If a bromide prjnt be treated with a solution of bichloride of mercury the image will disappear ; with the same treatment a platinotype will be unafl'ected. Shooter says : " A few weeks since I made a silver bath. I dissolved ten ounces altogether, and made a sixty-grain bath. I have now started using P. O. P., so I should like to know how to get as much of the silver back as possible. I only sensitised ten sheets in it." — The silver can be precipitated in the metallic state by placing in the solution a few strips of copper. But the more usual v.*ay is to throw down the silver as chloride by the addition of common salt or of hydrochloric acid, and then add the chloride to the stock of residues. W. Stephens. — 1. Although many rapid rectilinear lenses seem to be sym- metrical— that is, having front and back lenses absolutely alike, yet some are not so, hence you must return them to their cells, first one and then the other being placed to the outside, in fact, reversing their position as regards each other, and by aid of a magnifier note the effect upon the ground glass. 2. The rounded or convex surfaces must always be placed to the outside of the cells. It is rare that lenses of that type are confined to tlieir cells by counter screws ; they are usually burnished in. A. M. Z. asks " if there is much difficulty in accurately focussing pictures with hand cameras that require the distance to be estimated, the focus being ad- justed by a scale of distances engraved on the camera ? " — In reply : Some cameras are so accurately indexed that when the distance of the object is known a perfectly sharp focus may be relied upon when the index figure is set. We have tested this point with two such cameras in our possession, and find it to be so. Of course there may be some which are not so accu- rate, and with these it would be better to employ a ground-glass focussing screen. M. B. S. writes : "In your 'Answers to Correspondents,' please advise me what I should do with my nitric silver printing bath, which has unfortu- nately got an overdose of carbonate of soda, so much so that in printing the paper is quite powdery on the .surface ; filtering has improved it only a little." — If an excess of carbonate of scda has been added, carbonate of silver has been precipitated. Tliis will be again converted into nitrate of silver on the addition of nitric acid. Add nitric acid, drop by dro]i, till litmus paper is reddened. If the carbonate of silver has been filtered out, it is probable that the bath will require strengthening with nitrate of silver. J. Baktos writes as follows : "I have a lantern with four and a quarter inch condensers, and the lens is a No. 1b carte. When I enlarge a head and bust, or a vignette, out of a quarter-plate to 15 x 12, I get on all right, but when 1 try a quarter-plate landscape the comers of the pictures fall off fearfully from unequal lightings. I have always read that the lens that will take a negative the size of the one to be enlarged will do for enlarging it. The lens I use covers a'quarter-plate beautifully. What can be wrong '," —The fault is not with the enlarging lens, if it will take a quarter-plate negative— and probably it will — but with the condenser, which is not large enough. No four-and-a- quarter-inch diameter condenser will evenly illuminate a full-size quarter- plate. To do that, one of not less than five and a half inches is necessary. STKiKorTicfS writes: "1. My stereoscopic lenses are three and a quarter inches apart, my eyes are two and a half inches apart ; consequently the cntting and mounting glass stereoscopic slides present considerable diflicul- ties, wliich are increased when copying in the camera. I want a ready means of making slides in the eamera without cntting my negatives. By lessening the distance between the lenses, or preferably some other way, this ought to be easily done, but I do not at present quite see my way to it. 2. I want a new twelve-feet lantern sheet ; which do you think the best and most serviceable— pa. ler-covered or flatted in oil?"— 1. Knowing "Stere- opticus " to be an adept in making transparencies, we assume this to be the class of slides at which he aims. Tliree and a quarter inches apart is a fair minimum for the separation of the lenses on the camcm for taking negatives ; but, if the same lenses and camera are to be employed in transparency print- ing, it will be necessary to have them mounted so as to be adjustable as regards distance apart. 2. Both are good ; some prefer the one and some the other. West Losdon Photographic Society. — January 17, Technical Social Meeting. Messks Spicer Brothers are thanked for their " Driquic " blotting case. The blotting-paper is exceedingly absorbent. PhotooraTHIC Club. — January 18, Glass and other Fabrics for Dark Romn lUmiUnaiion. 25, Annual Lantern and Musical Evenmg. 27, Chil- dren's Entertainment. Kensington and Bayswater Photographic Society. — The subject of our next meeting, January 16, is Development by Amidol, by Mr. L. E. Morgan, and not as on the syllabus. Brixton and Clapham Camera Club. — .January 17, The Hand Camera and its Use in Picture-making, by Mr. W. Tliomas. February 7, The Optical Lantern with Special Reference to the Ether Light, by Mr. B. E. Pinder. 21, Stereoscopic Photography, by Mr. J. A. Butler. March 7, Lantern Slides. 21, Annual General Meeting. Huddbrsfield Photographic Society. — From .lanuary 1 this Society is .imalgamated with that of the Huddersfield Naturalists' Society, under the title of the Huddersfield Naturalist and Photographic Society, with Mr. Alfred Clarke, of St. Andrew's-rojid, Huddersfield, as Hon. Secretary, to whom all communications should be addressed. Forfab.shire Photographic Exhibition, 1893. — This Exhibition is to take place in the town of Forfar in April. The exhibits will require to be there the end of March. Sir John Rigby, the Solicitor-General, is expected to open the Exhibition. The prospectus and rules will be ready about January 20. The show will be international and open to all, and there will be awards, which will be made by a Board of Judges consisting of two photographers and one artist of good standing. The Louth and District Photogr.aphic Society's Tliird Annual Exhibition will be held in the Town Hall, Louth, on January 26 and 27. There are not any medals or other awards, the Exhibition being got up strictly for the ad- vancement of photography in the locality. To secure that end, the Exhibition is thrown open on both days free to the public. The Society defrays all ex- penses, including carriage of all exhibits kindly lent. All jiictures intended for exhibition must be mounted but not framed. Title, name, and address may appear on front of mount. Pictures must reach the Hon. Secretary, Mr. S. Francis Clarke, L.D.S., 8, Upgate, Louth, Lincolnshire, not later tlian January 23. On Wednesday evening, January 25, the Photographic Club hold their Annual Lantern and Musical Entertainment (Ladies' Night) at Anderton's Hotel, wlien, as usual, a large number of admirable slides will doubtless be shown ; and, as Mr. F. A. Bridge, the Hon. Secretary, is to be responsible for the musical portion of the programme, a treat in this direction may be safely anticipated.lf On the following Friday (January 27) the Club takes a new departure by providing a children's entertainment, to consist, we believe, of a selection of suitable slides, music, conjuring, ventriloquism, and other good things dear to the hearts of the juveniles. This entertainment (a happy thought in its way) is intended for the children of members and friends, and should be as successful as it will be novel. FORTHCOMING EXHIBITIONS. January 26, 27 *Louth and District Photographic Society. Hon. Secre- tarj', S. Francis Clarke, 8 Upgate, Louth. February 1 *Cleveland Camera Club. Hon. Secretar>-, J. J. Hallam, 11, Amber-street, Saltburn-by-the-Sea. ,, 7,8 Rotherham Photographic Society. Hon. Secretary, H. C. Hemingway, Rotherham. ,, 14 Durham City Camera Club. Hon. Secretary, R. Haux- well. The Avenue, Durham. „ 16-18 *Woolwich Polytechnic Photographic Society. Hon. Secretar)-, W. Dawes, 145, Chesnut-road, Plumstead, S.E. ,, 18 Holborn Camera Club. Hon. Secretarj-, F. J. Cobb, ICO High Holborn, E.G. March 1, 2 *Fillebrook Athen.-eum Photographic Society. Hon. Secretary, Joseph W. Spurgeon, 1 Drayton Villas, Leytonstone, Essex. April *Forfarshire Photographic Associrvtion. Hon. Secretary, W. J. Anckom, West Port, Arbroath, N. B. „ 17-29 «Photographic Society of Philadelphia. Hon. Secretarj-, R. S. Redfield, 1601, Callowhill-street, Philadelphia, U.S.A. * Signifies that there are open classes. OONTXIMTB, Paob keversed negatives for mecha- nical WORK 17 changing boxes yersvs dark 8L1DES,-II IS A seasonable printing process fob AMATECRS. By W. B. BOLTON 19 continental notes and news .... 20 WINTER troubles. By OLD COL- LODION ... 21 90M» CONTIIIBUTORIES TO ARTISTIC ■RESULTS. By A. HORKLEY HINTON 21 AN APPAHATI'" FOR THE DEVELOP- MENT OF JH 'TOORAPHIC PLATES WITHOUT I.JK USE OF A DARK BOOM. By ALEXANDER WATT .... 23 Paoi "BREADTH." By LUX 24 THE PINHOLE SOCIEmfg 0 JTING. By TOU COAN t.BBM ^ DERBY PHOTOGRAPiUC SOCIETY'S EXHIBITION 26 WEST LONDON PHOTOGRAPHIC SOOIETVS EXHIBITION 25 OUR EDITORIAL TABLE 26 RECENT PATENTS -26 MEETINGS OF SOCIETIES 28 CORRISPONDENCE SO ANSWERS 10 C0BRESP0NDENI8 21 THE BRITISH JOURNAL OF PHOTOGRAPHY. No. 1707. Vol. XL.— JANUARY :>0, 1893. ASSISTANTS AND THEIR SPECIMENS. We have willingly opened our columns on many previous (H'casions to the complaints and representations of operators, retoucliers, and others, of their having,' been robbed of their specimen pictures by the photographers to whom they had entrusted examples of work absolutely priceless to the sender. The heart of every honest man must burn within himself at the plain, straightforward accounts given by some of the writers refeiTcd to. Unfortunately, the class of man whose morality is of so low a grade — if it be permissible to establish tlegrees of mental turpitude — as to allow him to rob, in this heartless fashion, those able workers who reply to his advertise- •ment, and, after having filched their goods, traded on their Abilities, is utterly insensible to any appeal or reproach for his •callous and nefarious treatment. The only way to treat him «nd liis kind is by the strong arm of the law, which, more the pity, is often too slow for its strength. A short enforced retirement to study the intricacies of tarred rope, once applied, if such could possibly be brought about, would have more effect than jjages of writing. On this subject we feel more strongly than we care to put into words ; but at the same time we feel bound to say that there has rarely been a more cogent instance of the value of the •old proverb, "Amli tt/temm partem," than is afforded by the cases of wrong we are now considering. We had i-ecently occasion to call upon a professional photographer, and, when ushereil into his presence, were asked to excuse any violent language he might have been heard to use, for he was busy replying to advertise- ■inents, and much ruffled by tlie labour thrown upon him in •i-onsequence of the unbusinesslike mode in which the applica- cations were made. " Yet," said he, " let me but lose or mis- send one single picture out of all this heap, and it will at once become the most treasured property of its owner, and there •will be a howl of indignation from one end of the country to the other at the infamous way in which I am treating applicants for a post." There can be no doubt that the photographs sent in reply to an advertisement, and the letters of application accompanying (or belonging to) them were of the most unbusiness-like kind. Beautiful photographs actually sent with no protection but a Nsmall piece of cap-paper tied with a piece of string ; others well tied, but guarded from the sorter's stamp by nothing stronger than writing paper ; others suitably and sufflciently 'packed ; othei-s, again, with small and large pictures placed higgledy-piggledy, and no guarding sheets between. A business-like man would at once reject an untidily got-up .application if one of equal merit were to hand in which every- thing was neatly and securely put together. But, as this is merely by the way, not forming part of our especial object in writing, we pass on to the next point. Not only are pictures insufficiently securely packed and tied up, they are actually sent without any distinguishing mark inside, except perhaps a piece of paper marked " Portrait of self" Seeing that every one is a " self" at the time of writing, it is evident that some- thing a little less vague would be desirable for identification. In the instance we were referring to, the photograplier informed us that ho actually had to guess by internal evidence whom certain of the lots of portraits belonged to. The postmark is not enough ; more than one may be writing from the same town, and incontestably it is asking too much of the proprietor of any large establishment that out of a score or two, or three, or four applications he should be put in the position of teing able to find the address or owner of a good proportion of the photographs sent only by submitting them to a rigid scrutiny and classification of postmarks, dates, handwriting, and so forth. What wonder if now and then some employere, of not over-gentle mien, do retaliate by pitching the unmarked photographs into the waste-paper basket ! We do not uphold him in such a mode of dealing with them ; we point out the possibilities. Now, as such remarks as these lose some of their value if not made thoroughly practical, we offer the following advice to any one replying to an advertisement involving specimens being sent at the same time : — Use some judgment as to the probabilities of the cisc, seeing it is notorious that specimens have been withheld by tho receivers. Let the producer of the jiii-ture or retoiu-her who sends samples of his work write his name legibly on every individual print, doing ic on the face if he like, so as to avoid temptation to use it by others for dishonest purposes. Let the parcel be well packed and covered by strong lx)ard8 to protect it against stamping and damage in transit ; post officials have no special regard to the contents of every indi- vidual package that goes through their hands. Let a very brief descriptive list accompany the prints, setting forth the number and style of prints, and the fidl name and address of their sender. Do not send any original testimonial at the outset. Let the outer wrappers be in good condition, and be legibly readdressed (to tho owner on the inner page, so that, when the advertiser returns the pictures to their various owners, the lea.st labour may be involved). If it be assumed that an advertiser receives a score of applications, any one who has any knowledge of such things will say that, unless some such method as above 84 THE BRITISH JOURNAL OF PHOTOGRAPHY. [January 20, 1893 advised be adopted, a half-day's steady, continuous work will be absorbed by cxiiminiug specimens finding out their owners' addresses, packing up and addressing the parcels again, not to speak of the possible courtesy of an accompanying "declined with thanks." Finally, we advise that stamps for reply and redespatch bo enclosed; they are not essential, and some employers do not look for it, but it is ftir safer. In conclusion, wc feel justified in saying that, if such a method of application here shadowed forth had been in general use, we should have hoard less in time gone by of the robbery of speci- mens by advertisers. NOX-ALKALINE DEVELOPMENT. Of late we have observed in foreign photographic journals more han one communication implying that, for the development of the photographic image on the hfiloids of silver in gelatine, tmany organic bodies recently experimented with were available which would answer the purpose when allied with an acid instead of a free or fixed alkali. It is, therefore, with singular opportuneness that we notice a paper contributed to the Pro- ceedings of the Si>*-i<'tt- Fraw;aue de Pkofogrnpfiie a few days ago by those indefatigable experimentalists, Messrs. A. it L. Lumiere, which has a distinct and valuable hearing on the matter. Messrs. Lumiere point out that, while hydroquinone, eiko- nogen, and para-amidophenol, :*^:^ THE SUTTON'S PROCESS SYNDICATE, LIMITED. January iO, ISO.'j] THE BRITISH JOURNAL OF PHOTOGRAPHY. iir, fixed lid, and commtinication is made with the interior. The changing box is thus practically automatic in its opening. The opening and closing of the slide is effected by means of a spring back acting in a very similar manner to Hare's changing slide. A catch is provided, by means of which tlie sliding lid is kept secure in tlie various jjositions it has to occupy. In use the box work.s precisely as we have already described. One side is marked " out," the other " in." When a plate is required for exposure the slide is inserted in the jaws, and the sliding lid moved as far as it will go in the direction of " out," which is then in the uppermost position, and the top plate ■slides easily out of the box, the jaws of which are then closed. After exposure the process is repeated, the " in " side of the 'box being then uppermost, and the exposed plate is returned to the back of the stock. To prevent the risk of re-exposing any of the plates, should a miscount occur, a piece of thin wood or millboard, the same size as the plates, but just too thick to pass through the slot, is placed behind the last plate or carrier, so that when the latter has been exposed the refusal of the " dummy " to pass announces the fact that the stock is exhausted. In order to guard against the possibility of a plate being taken out of or returned by the wrong opening, each is provided with a thin metal flap — which may or may not extend the whole length of 'the slot — which, held in position by a light spring, will open by the weight of the plate or carrier in only one direction, and these, being fixed in reverse position over the two openings, •efifectually prevent the plates being passed through the wrong ■aperture. Finally, if double carriers arc employed when the whole have been exposed once, an extremely simple arrangement permits the dark slide to be inserted in the jaws in the opposite direction and the reverse siHes of the carriers can then be exposed. In this ■case, however, the safety flaps just mentioned must be removed at the time the box is charged, and it will be needful to bear in mind that the directions " out " and " in " bear an opposite signification. We had nearly omitted to point out that in employing double carriers the dark slide must be filled with four separate back springs bearing on the corners of the carrier, instead of tlie usual central springs ; and, as these are as easily applied, it is perhaps better to substitute them in all cases where thin metal •caiTiers are used. So simple' is this arrangement that there is absolutely nothing to get out of order, and scarcely any room for making mistakes if a systematic numbering of the double carriers — should such be used — be adopted. It is equally adapted for glass plates or films, but will no doubt prove most useful with the latter, the box to carry fifty films in double carriers having a thickness of little more than an inch and a half. The film-carriers employed in this apparatus have also the advantage of extreme simplicity and perfect efficiency, combined -with lightness, cheapness, and the fact that they are within ■the power of construction of any one. They consist merely of narrow strips, say a little over a quarter of an inch wide, of ■thin metal bent in the direction of their length, so as to form a T section. Those are cut to the length of the longer side of the film, or the direction in which it slides, and others about a ■quarter of an inch shorter than the other dimension. A number of pieces of opaque paper — ordinary brown paper answers perfectly — are cut the size of the films to be used, and these, "sandwiched" lietween two sensitive films, are bound together at the edges by the metal strips, forming one of the cheapest, lightest, and l)est carriers we have seen, ^e films lying perfectly flat, and being protected along all four edges. 'I'licy may, of course, l)e used as single cfirriers if desired, and tliin metal or cardboard may be used instead of paper for tlie opaque division if greater stiffness be wanted ; but the metal edging forms a quite sufficiently rigid frame for all ordinary purposes. We have seen another changing arrangement, in which a separate slide is dispensed with, or in which the slide itself forms the receptacle for carrying the films. In outward ap- pearance, it closely resembles the slide of Hare's changing box, only thicker, and is provided with a changing bag attached to a sliding plate that fits into the end when a film is to be changed. AVhen this is necessary, the bag is slid into position, and a spring catch is released, as in Hare's slide, which, how- ever, opens li'.'o slots, out of one of which the exposed plate emerges, to be seized by the operator's fingers ; and, after re- versing the slide, it is reinserted at the back of the store, and another surface comes into position for exposure. There are numerous little details in the internal arrangements necessary to the smooth working of the affair that would require diagrams for their proper explanation ; but the general idea we have given will enable any intelligent mechanician to construct sach a changing slide. We have described these forms of apparatus in the hope that some of our manufacturers may be induced to take up, and perhaps improve upon, the ideas, and thus supply the want of a really portable arrangement for carrying large numbers (rf cut films. Pbotographers' Risks. — riiotogravhers frequently incur great risks in the practice of tlieir art. Often they will jeopardise their lives, sometimes unnecessarily, in positions that few would ven- ture, in order to obtain a particular view or effect. Here is a ca.se in point Last week two photographers were taking views in a cave at Niagara Falls, when a huge icicle became detached and fell upoa them, hurling them into a chasm below. After a time they werd rescued and taken to the hospital. One is expected to recover. Of the other no hopes were entertained. It is to be hoped this may serve as a warning to over-venturesome enthusiasts in the art. A Sis' Susiness.- It was stated in the evidence at the Tolke- stone Police Court tlie other day, re the Treasury prosecution in the "free portrait" swindle, that no less than eight clerks were employed in the business. This can be understood when from two hundred to tliree hundred letters were received daily. What do struggling photographers think of that." It appears that the police found nearly 2000 portraits on the premises. This represents the number of disappointed individuals who expected to receive a two-guinea picture for nothing. After the frequent exposure of the fraud dming the past few years, some may be inclined to say " serve them right." Sutton's Kalf-tone Process.— In the announcement pages of our present issue will be found two examples of Mr. Henry Sutton's half-tone process which our readers will remember we described in the Jounx.VL for November 20, 1891, p. 737. In addition to rapidity and cheapness of production, these cliches are of a nature to admit of being printed with ordinary letterpress with fast-running machinery, which should prove a considerable boon to conductors Of illustrated periodicals and tliose requiring phototypic reproductions expeditiou.sly and at a low cost. It will be observed that the results, of which an excellent example is to be found in our Almanac, compare favourably in their artistic qualities with half-tone pictures obtained by other methods that have been employed for some tune past. 36 THE BRITISH JOURNAL OF THOTOGRAPHY. [January 20, 1893 Frozen Water Pipes. — In our last issue a correspondent details his experience of the effect of the frost on a porcelain dish. We fear, ere this, many of our readers have had a more costly one in the shape of burst water pipes. It is somewhat surprising at this age to find that the once popular idea, that the bursting of a frozen pipe takes place at the thaw, still prevails with some persons. It would be superfluous to tell our readers that the fracture occurs at the time of freezing, although it does not make itself manifest until the thaw. But it may be well to remind them that the fracture can always be discovered, and the injury repaired, before a thaw sets in. When a pipe is found to be frozen, it should be carefully examined throughout its length, when the burst, if any, will be easily seen, or even felt. If this were done, many annoying and costly floodings would be avoided. A False Alarm. — At the conclusion of the meeting of the l^ondon and Provincial Photographic Association on Thursday, January 12, Mr. J. G. Hudson gave a practical demonstration of his Kolm magnesium flash-lamp, when several exposures were made by Messrs. Teape and Freshwater. In the course of the demonstration a considerable quantity of magnesium was used, so that a tolerably large volume of smoke resulted. To allow of its escape, the windows were opened, which, in conjunction with the unusually large and brilliant flame of the lamp, so alarmed a civic policeman that he blew his whistle, with the consequence that in a very few minutes three or four fire-engines, together with a fire-escape and a crowd of people, had assembled, under the impression that a conflagration had broken out on the premises occupied by the Association. The inci- dent caused much amusement among the members and no little temporary alarm to the authorities of the hotel. Strong' versus Feeble Iiig'iit. — There is a point in connexion with the sensitiveness of different materials to light that just now it may be well to direct the attention of experimentalifts to, particularly those with the photo-mechanical methods. Some compounds are relatively much more sensitive in a strong light than they are in a ■weak one — that is to say, a proportionately longer exposure in a feeble light is not equivalent to a given one in a strong light. Notably is this the case with bitumen, so largely used in " process work," and bichromated gelatine in the other processes. With tl e former, in a weak winter light, several days' exposure will not bring about the same result that can be obtained in a few minutes in a bright summer sunshine. The same also applies to bichromated gelatine as used in collotype, photo-lithography, and other processes — a longer exposure in a dull light does not secure the same re- sult as that obtainable in a bright one. Most carbon printers, for example, know that in a strong light the tissue is much more sensitive than albumen paper, but in a weak one it is very much slower. Some- times, when the light is exceptionally bad, double the exposure will be required. Recipes and Recipe Books. — One or more recipe books are usually to be met with on the shelves of most photographers ; but, as many have discovered to their cost, not a few of the recipes as given are by no means to be relied upon, while some are nothing less than impossibilities in practice. This remark applies not only to cheap works, but also to the more expensive ones. The compilers of these works have in many instances adopted formulas that have been handed down from generation to generation in older works, sometimes with printer.s' errors, without any kind of verification or comment. This should not be the case, for nothing is more annoying than, after taking every precaution to work strictly according to the recipe, that, in the end, the thing is impracticable. In a technical work now before us are six or seven different formula; for French polish, a material often wanted by photographers. In these the proportion of resins to spirit •vary from one ounce and a quarter to five ounces and a quarter to the pint. In some only two resins or gums are given, in others there are half a dozen, some of which are not even soluble in spirit — gum arable, for example. It is not unusual in some books to find the same material under different names given in the same recipe. WILLIAM BEDFORD. With a feeling of sorrow, which we are sure will be shared by all our readers, we announce the death of Mr. A\ illiam Bedford. For some time he had not enjoyed robust health, this having been noted when, as President of the Bath meeting of the Photographic Convention of the I'nited Kingdom, he so ably fulfilled the duties then devolving upon him. Mr. Bedford was a man who was univer- sally esteemed, and was foremost in every good work appertaining to the welfare of photographers and the advancement of photography. For several years he was the Chairman of the Council of the Photo- graphers' Benevolent Association ; and with what honesty of purpose and assiduity he threw himself into the work of ameliorating the condition of his less fortunate brethren only those know who were associated with him in this beneficent institution, from which no worthy applicant for assistance has ever been sent away empty. As a careful, pains-taking experimentalist Mr. Bedford had few equals, and when in his own singularly modest way he expressed an opinion on processes or methods based on his own investigations, it was felt by those who listened to him, with that deference which invariably attended his utterance, that they might be accepted as conclusive. He was an active member of several Societies, including the Photo- graphic Society of Great Britain, of which he has for several years been elected a member of the Council; the Photographic Club, of which be was a Trustee ; the London and Provincial : an honorary member of the North London Society ; and one of the active pro- moters of the Affiliation Scheme in connexion with the P.S.G.B. Individually, he was an artist of great merit, and frequently was awarded medals at the higher class of exhibitions, the last being at the recent Pall Mall Exhibition. He received his education in the science of photography at King's College, the practical part being acquired in the studios of his father, Mr. Francis Bedford, the eminent landscape photographer who accompanied H.R.H. the Prince of Wales on his Eastern tour many years ago. He died of t_vphoid fever on Friday, January 13 last, aged forty-six years, and was buried at Kensal Green Cemetery on Tuesday, the 17th instant, amongst those assembled at the graveside to pay the last tribute of ret-pect to him being several members of his family ; personal friends ; and employes, and Messrs. F. A. Biidge, F. P. Cembrano, jun., Alex. Cowan, R. Child-Bayley, W. E. Debenham, R. P. Dr.ag'e, A\'illiam England, E. AV. Foxlee, H. M. Hastings, II. R. Hume, Alexander Mackie, E. W. Parfitt, John Spiller, J. Traill Taylor, G. W. Tottem, Horace Wilmer, &c. The large circle of friends William Bedford had made and re- tained ensures wide sympathy for his wife and son, and for his aged and esteemed father, Mr. Francis Bedford, in their afliiction. He will long be remembered for those amiable gifts of character which endeared him to so many, for it is safe to saj" that seldom in one man was there concentrated so much kindliness of disposition, courtes}-, warm-heartedness and generosity, allied with those admirable qualities of mind which elicited the respect as well as the affection of his numerous acquaintances. Our portrait, which was the last one taken of him, was reproduced for us by Messrs. B. Dellagana & Co. of Shoe-lane, at short notice. Art Reproductions. — Seeing the extensive sale that photo graphic copies of some of the pictures in Continental galleries, aud modern Continental paintings, command in this country, one is natu- rally led to speculate as to whether reproductions of the works i English galleries, as well as British modern works^ would not meet with a similar sale if they were forthcoming. Of course we mean h. the sizes and at the prices that the foreign productions are to be obtained here. It is often said that the British public gener.illy dv' not care for art, but this, to an extent, is disproved by tiie tact of xim large business done in the foreign copies. English publishtrs di not apparently care to issue reproductions of paintings in which tiio^ are interested in anything but large sizes and at high prices, and in tn they are generally supported by the artists. Foreign publishers, o-a January 20, 1803] THE mUTISH JOURNAL OF I'lIOTOUUAi'IIY. [Supplemeot WILLIAM BEDFORD. Died January 13, 1893. January 20, 1893] THE BUITISH JOURNAL OF PHOTOGKAPHY. 37 tho contrary, issue several sizes, from cabinet upwards, printed in silver and carbon as well as collotype, and at pojiular prices. These pictures are available for either albums or folios, ■wi)ereft8 the expensive Knglish reproductions are only suitable for framinj^. In connexion with tliis topic wo are given to understand by print dealers that the copyriglit in tlie popular Oeriiian picture, 'Aa jl/ot7.- Ti/rolese' h&a (iroved one of the most profitable of late years. Copies of all sizes and by all processes have, for some years past, met with an exten.sive sale, not only in England and the Continent but also in America. STUDIO IIE.VTING. Ocn BSteemeJ Editor, knowing I have had considerable actual exjierience in this subject, and having asked me to give my views upon it for the benefit of any reader of the Journal who may be contem- plating adopting some one or other of the many methods recommended by persons interested or otherwise, I will do my best to carry out h'n wishes. So many studios being connected with dwelling-houses, it is natural that first thoughts would turn to tho open fireplace, and I may say at once that T share the Briton's prejudice in favour of a good, hot, coal-fire ; but it has certain disadvantages that render it at times the very worst heating medium possible. There are few chimneys which do not occasionally "smoke;" that is to say, the smolie, instead, of ascending the nice channel made for it, occasionally comes, instead in putTs into the rooms. This is annoying enough in a living room, but in a studio it simply means cessation of worl; for a long period afterwards : for it is difficult enough at this time of the year in the be'st weather to obtain a sufficiently clear atmosphere to enable one to take good portraits when the camera is any distance from the sitter, as for half or full-lengths. It is within the at&ik to say that, with a slightly foggy air to start with, no good negatives can be taken for an hour or two after one whiff of smoke, be it ever so slight, has come into the room. ' Hence, unless the chimney is known to behave perfectly — and bow few have such a good reputation ?— it will be better to eschew open fireplaces. Of course, if the draught be con- fined by restricting the open area of the grate by sheet-iron " blowers,' or otherwise, there will be less danger of smoke. I have employed this plan witli a very small fireplace, which I had specially lined with fire-brick, after finding the ordinary brick burnt out with a few weeks use. ]5y using a blower coke can also be conveniently employed, which reduces risks of smoke to a minimum. There is always, how- ever, the danger of the " boy " — ubiquitous when mischief can be done — exercising the usual carelessness when lighting the fire. One further reminder, and we may consider another aspect of the subject With open fires, even with perfect chimneys, there is always danger of smoke being blown down by the wafting of a lady's dress or similar cause. Those only wlio have experienced the ill effect of a slight amount of smoke in the air of the studio have any idea of the miseries it causes. Far better are closed stoves, of which there is an infinite variety to choose from ; but a good-sized slow-combustion stove, if room can be found for it, or a couple of them if the studio be a long one, is a very efiicient mode of warming a studio. Their drawback is the unsightly flue or stove pipe needed for carrying off the products of combustion, though in this respect the makers are very accommodating, and now- adays construct them so as to reduce this disfigurement to a minimum by carrying the pipe downwards. This, however, implies a chimney near at hand to lead these portable flues into, and they also need a good draught, or the stove will not work. Further, there must not be lost sight of the pleasures of taking the pipes down periodically for cleaning, with the attendant dust, and dirt, and soot particles. When 1 had one of these in use, it was generally discovered that the flue wanted cleaning just when taking down the pipes would produce the utmost possible upset and inconvenience. I have had personal experience of the building, in various places, of not much under a dozen studios, and if I built that number again I candidly say that I .should be thoroughly averse to any method of heating that involved the slightest possibility of the entrance of smoke into any room where a portrait would have to be taken. It is very probable that throughout the country many a negative is produced with foggy characteristics all owing to the presence of smoky air, so slight as not to be noticed by tho inexperienced, and for which de- fects the unfortunate plate-maker is blamed. These smoke troubles are by no means confined to the fuliginous particles that escape from fires in tho studio, for, if there be an open tire in adjacent dressing-rooms, any smoke wafts entering them will inevitably result in the ultimate contamination of the .studio air. Indeed, one of the defects of studios situated over dwelling-houses is tlie liability to the entry of smoke from any room from basement to attic in which a fire is burning. Witli the knowledge of all these possible defects, gained by painful experience, I advocate most strongly a system of heating by hot water. I built a very large studio more than twenty years ago and heated it in this way, and when, after seven or eight years' occupa- tion, I left the premises I had the very same apparatus removed and set up in my next studio. They are in use now, apparently as good as the day they were first put in, and, I think, do not cost any more than — if as much as— I should have to pay with open fireplace.';. The heat is produced in a brick furnace in the cellar, and the pipes traverse the studio, tlie dark room, a dressing-room, and my office, and there is never any complaint; sitters often say, "How comfortable the studio feels — just like a sitting-ro»m.'" This is high praise, for one most important matter in professional portraiture is attending to the physical comfort of the sitters. Whatever the cost, it is money well laid out. Every one, of course, will have his own preferences as to the par- ticular kind of hot-water apparatus to employ. The one referred to is on wliat is known as the high-pressure system. Tlie pipes are of narrow bore, the external diameter is only an inch and a half; there is no boiler, no safety valve, no water reservoir, all is self contained, and the last addition of water was about a wineglassful after over two months' constant use. The pipes for the high-pressure system are made of wrought iron, and so instead of the utisightly pipes of the more familiar liiiid occupying space and pulling premise.* to pieces when they are put into a series of rooms in a building already erected, there are merely these narrow tubes invisible in comparison with the others, which can be carried through room after room and requiring little more wall piercing than could be done with a good-sized auger. I should like to say before concluding my remarks upon this branch of the subject that there is much to he gained by keeping the water hot night and day. In my own premises the tires are never allowed to go out during the winter ; the furnace was lighted early last autumn, and, except for a few minutes occasionally while the slags are being laked out, has been burning ever since. The fire is banked upatnight,and neit morning is still alight,and studio, dark room, and dressing-r^iom ar» at a most pleasant temperature however early work begins in the morning. What this means will be well understood by operators and others who, during such weather as we have lately experienced, come to cold rooms first thing and have to wait some hours before there is any real comfort. I will conclude my remarks by reference to gas stoves, which are highly approved of by many. There cannot ))e two opinions as to their convenience, and, if sufficiently large, and supplied with gas through-pipes of large enough bore — a very unusual thing — they are efiicient. They are also rather expensive when used at full power for large studios, there being usually such a considerable amount of ventilation, or air change, through the glass rccrf and otherwise. My own experience of this form of heating has been con- fined to dressing-rooms of late years. I have one of Fletcher's in use for that purpose, which can be turned on and off just as required, and thus is decidedly economical, and free from possibilities of my /lete noire— smoke. It may be well to point out that the manufacturer named makes three types of gas fires, in which the incandescent materials are respectively asbestos fibres, hollow fire-clay balls, and corrugated iron, tlieir economy of gas being most with the last named, and least with tho first. There is, however, with the asbestos pattern power to turn the gas down — when full power is not needed — to » much greater extent than the others. In them, if the gas be turned too low, the flame passes down to the inner jet. and then lights, like a Bunsen with too much air supply. When that happens no value is obtained from the gas, and, what is still miire important, this jet becomes coated with soot, the supply of gas is lessened, and it this lighting down be not noticed and continue for some hours, tho THE BRITISH JOURNAL OF PHOTOGRAPHS [January 20, 1893 choking up of the jets is so great, and the efflux of gas so reduced, that it is with the utmost difficulty that when next required for use the burner can be lighted properly— the flame will shoot down and tery little heat is obtained. I allude to this owing to my liaving seen ^as fires in this condition ; it was only a week or two ago that I ■was in a professional friend's studio whose burner was in the condition I describe without his being aware of the fact. In concluding my brief survey, I can only say I hope some of my readers may gather useful hints from it; and, if I can throw light on any obscure point, I shall be happy to supplement it by details of personal experiences. G. Watmough Wbbstbk. AMERICAN NOTES AND NEWS. The Social Status of Photoeraphers.— In the Canadian Photo(/i-ajihic Jnurnal, Mr. John Clarke recommends his brethren to adopt carbon and platinum printing, in order to impart variety to the contents of their reception-rooms, and bring them pecuniary success. He adds : " But the exhibition and judicious introduction of such pictures will do more, it will help to raise the tone of the establish- ment in which they are produced, probably a more valuable thing. It will be admitted, and it is true whether admitted or not, that photographers do not as a rule enjoy the social status to which they are entitled — are not, socially, on the plane of, say, the doctor, the llawyer, or the clergyman. It is true that a few who are commercially Successful enjoy the social position that is an attendant on weal'h however produced, but the great bulk of the fraternity are, in pull estimation, merely photographers. Much has been written about the status of photography, but photography itself is all right enough ; it is the status of the photographer that needs raising, and anything that will act as a lever in that direction should be regarded with favour." The social status of English pliotographers, according to the foregoing reasoning, is higher than that of their Canadian confi-crcs, inasmuch as here platinum, carbon, and other methods of printing only slightly in favour in America are largel}' practised. By the way, is not Mr. Clarke somewhat rash in assuming that platinum paper — or, indeed, any sensitive paper — will keep " indefinitely ? " Semedies for Over and TTnder-prlnting:.— A method of treating prints which have been over or under-printed has been recently devised by Mr. J. liuntly, says Antkont/'s Bulletin. Those that have been over-printed are toned and fixed in the usual manner, and then immersed in a dilute solutiom of cyanide of potassium until reduced to the desired shade, when they receive a thorough washing ib running water. Under-printed proofs are developed with hydro- quinone in the same manner as a negative, and then finished in the ordinary way. The results obtained are said to be excellent, and we would advise our readers to make the experiment. A " Mew " Ceramic Process. — According to the same journal, Mr. Geo. G. Rockwood, of New York, has recently invented a method for burning in photographs on glass which bids fair to become a very important one. " It is based on the property that gelatine possesses of becoming insoluble when exposed to light in the presence of a bichromate salt. Indestructible pigments are combined with the gelatine, and remain upon the glass after treatment with warm water, wherever it has been affectad by the light, as, for instance, exposure under a negative. When dry, the glass is fluxed and placed in a kiln, and the pigments melted into its surface." Anti-halation Plates.— Plates spti-ally coated to avoid haktion in interior work are being introduced by American manu- facturers of dry plates. ' The .M. A. Seed Plate Company have, it is Said, such a plate on the market, and the Wuestner Eagle Dry Pkte Company are also preparing a similar plate. On behalf of English plate-makers we here take leave to acknowledge the delicate compli- ment paid to them by our American friends in fallowing the former's lead. A Coin-controlled Stereoscope. — A patent (in the United States) has recently been taken out for a "Coin-controlled Stereoscope." The claims relate to the special construction and arrangement of parts for uncovering the object-glass, bringing the views into position, &c. Electricity, in conjunction with clock-work, is utilised as the motive power. A Oivided Interest. — " Watchman " in the Beacon writes : " 1 learn from WiUoiis Mac/aziue that one of its subscriberi has lono- divided his attention between photography and grape-culture. I have known many who divided theirs between photography and the fruit of the vine, and my observation has led me to believe that, attractive as photography is, the grape, especially when it has been corn or rye, sooner or later ousted his colleague." Not always, we hope and believe, good " Watchman." "A Useful Dodg:e for Aristotype Printers."— Mr. J. H. Reuvers, in the Pliatoyraphic Timex Annual for 189."), says : " Users of aristotype paper very often are annoyed in their printing by having some of the paper stick to the negative. If not successfully removed, an entire negative may thus be ruined. I have hit upon a dodge which removes the difficulty completely without injuring, the nega- tive in the slightest. Immerse the negative which has thus been marred in a hvpo solution, and leave it there until the brown spots or streaks caused by the paper have entireh- disappeared. Then remove the negative from the hypo bath and wash thoroughly by aying the negative in clean water, changing the water frequently. Do not allow the water to run on the negative, ns it would remove the retouching. When the hypo has been removed from the plate by washing, remove the negative from the water bath and set it up to dry in the usual manner. If the process is accomplished with care, the negative will dry as perfectly as if nothing had happened, aud the retouching even will not be marred." This reads like a very simple method of removing silver stains from negatives. Perhaps some of our professional friends will try and report upon it. NOTES ON SILVER. [American Journal of Science.] Action of Ammonia. — Aqueous ammonia is supposed to be without action on normal silver, but this is not so ; under favourable conditions, silver is gradually taken up by this solvent. The first experiments were made with silver reduced from the nitrate by the action of sodium hydroxide and milk sugar. The silver was very carefully purified from any possible trace of oxide. Placed in contact with ammonia for a few hours, silver was taken up. Its presence could be recognised either by ammonium sulphide, or by adding a drop or two of hydrochloricacid, and then supersaturating with dilute sulphuric acid ; a dense cloud of silver chloride forms, and this result can be obtained any number of times in succession by acting with ammonia on the same portion of silver. A similar reaction was obtained with silver reduced from chloride by cadmium and hydrochloric acid, removing afterwards all traces of cadmium. Silver reduced in this way is liable to contain trace's of chloride. These were removed by covering the silver with strong ammonia, letting it stand over night, and thoroughly washing out. This was repeated five times. From this silver, ammonia by twenty- four hours' contact always took up enough to give a dense white cloud when treated as above. Portions of solutions obtained in the last-mentioned manner were evaporated to dryne.ss over the water bath, and left brownish-black films. These were non-explosive, and therefore did not consist of silveramine; they yielded a large proportion of silver to acetic acid, leaving behind a little metallic silver. The ammonia, therefore, does not dissolve the silver as metal, but as oxide. The presence of a little metallic silver in the residue left by evaporation wa^ probably due to slight traces of oxidable organic matter contained in the ammonia. This opinion was confirmed by the fact that the solution, when heated, acquired a transparent red colour. It appears, therefore, that, in the presence of ammonia, silver has a tendency to oxidise, for when the silver was plar-ed in a vial with an air-ticrht fitting stopper, fiUing it about half full, and was then completely filled with liquid ammonia and tightlv closed, it was found that in twenty-four hours a mere trace of "silver was taken January 20, 18931 THE BiUTISH JOURNAL OF, PHOTOGRAPH if. 80 lip. Oil tliu otJiflr hand, whon the silver was plnced in a flat Imsin and murely inoistiMied with amiiiDnia, moro silver was taken up in five minutes than in the preceding' case in twenty-four hours. This act ion of ammonia in proraotinpr oxidation recalls its behaviour with cobaltou.s salts and with copper. It is probably the only case in which silver is oxidised (at ordinary temperature) by atmospheric oxygen. Action nf IHMc Siilplmrw Acid. — It is jronerally held that silver is insoluble in cold dilute sulphuric acid. Almost any form of silver, provided it is finely divided, is slijfhtly soluble in sulphuric acid diluted with four or five times its bulk of v/atcr. With more dilute acid, different varieties of silver net very differently. The most easily attacked is that which is obtained by reducing' the o.tide with alkaline hydroxide and milk sugar; from this a distinct trace is dissolved by sulphuric acid, diluted with 1(H) times its bulk of water. From silver reduced from the chloride by cadmium, this very dilute acid takes up nothing. Xitric Ill-ill. sp. gr. 1'40, diluted to ten volumes, and allowed to stand for an hour with finely divided silver, took up an extremely faint trace. HyihiH'Moiic iiriil, sp. gr. 1'20, was totally without action. The silver, after being well boiled with water to remove every trace of acid, dissolves completely in nitric acid. Acetic mid has no action upon metallic silver. \"AmoPs KEA.crio.vs of Normal Sii.veu. Normal metallic silver, even in a state of very fine division, does not abstract the .slighte.st irace of nitric acid from perfectly neutral cnpric nitrate obtained by acting on pure cupric sulphate with barium nitrate. After fifteen hour.i of contact, not a trace of silver had been dissolved. But silver easily reduces cupric chloride with formation of purple photochloride. If the copper salt is present in slight excess, the silver is so thoroughly acted upon that nitric acid does not extract a trace of it from the purple photochloride. Metallic mercury instantly reduces silver nitrate, but metallic silver takes chlorine from corrosive sublimate, The precipitate contains calomel and blackens with ammonia. Silver in fine division slowly reduces a neutral solution of potas- sium permanganate. Silver nitrate, as is well known, is deduced by ferrous sulpliate or ammcmia ferrous sulphate, the iron at the same time becoming per- oxidi.sed and the silver assuming the grey metallic form. On the other hand, silver powder rapidly reduces a netural solution of ferric sulphate. A solution of iron alum readily dissolves metallic silver without the aid of heat ;* in a few seconds the solution strikes a blue colour with potassium ferricyanide, and if the iron alum is in excess the whole of the silver is di.ssolved. It has been before noticed that the reactions between silver salts on the one hand and iron salts on the other are to some extent reversible : the obser- vations just described place the matter in a somewhat clearer light. AVith a view of itscertaining whether ferrous sulphate could be completely oxidised by argentic oxide, a portion of the ferrous i-i>lution was treated with successive portions of tho oxide until the latter was no longer affected by it. Hut when this stage was reached the .solution no longer contained a trace of iron, the whole of it had entered into combination with the silver. This com- bination is perfectlv black, and m:i3' probably have consisted of the compound described by II. Itose as AgjO, 2FeO Fe.^O^, and obtained in the same way. When ammonia iron alum is placed in contact with finely divided silver in considerable excess in a tightly closed vial, the solution, after a few days' standing, with frequent shaking acquires a deep red colour. This may last for a week or more. The solution then de- colourises, and becomes greenish, but still contains abundance of ferric salt. Thus it appears that, although silver has a powerful reducing action on ferric salts, the action is self-limited, and ceases long before complete reduction is effected, for, after many weeks' contaet in a closed vial, there are abundant indications of the presence of ferric salt, although silver has been present in large excess. M. Cabei Lba. ESTIMATION OP OXYGEN. I_l,<»udon autl Provincial Photoffraphic Association.] I.v bringina; before you such an out-of-the-way subject as the estimation of oxygon, we are chiefly influenced by the hope that it * Tliestiitemeut in the new En-yclopldk ('himi-iiie that heat is rei|uired and that the metal separates again on cooling (tome iii., cahier 15; p. 248) apiiears to be incorrect. may be of .some use to the largo section of photographers who practiso lantern work, and who use oxygen compreM.secl in cylinder*. Tint this oxygen may be of more than doubtful purity, -was poiotetl out recently by Mr. Ilopworth in a li-tter to Xature, and who had obtained results showing from .'5 to •t-'i per cent, of impurity, which has also lieen the experience of one of us. We need hardly point out that not only has tho amount of impurity present in oxygen a verv bad effect on tho light given out— when used for producing tho lime- light— by coohng the flame, but also on tho pocket of the lantemist, by his having to use more gas than he would otherwise have to do if the osygen were pure. VaHIOUS Wa-JTS of ESTIMATIJfO OxYGEN. To estimate oxygen very accurately, complex apparatus such no Bunsen's, or modifications thereof, in which mercury is the trapping fluid, must bt) used, but for ordinary purposes llempel's, or some such apparatu.s, in which water is the trapping fluid, may be em- ployed. The estimation of oxygen in a mixture may be carried ont in several ways, of which the two most important are, finit, by mixinpr the gas to be analysed with an excess of hydrogen, exploding the mixture hy means of a spark from an induction coil, and measuring the decrease in volume. One-thir'l of the contraction, due to the combination of the oxygen with the hydrogen, will be the volume of oxygen present in the original gas. Second, by bringing the gas to be tested into contact with a solution of pyrogallic acid and caustic potash, and noting the decrease in volume which occurs. Tlie diminution in volume gives the amount of oxygen present in the original mixture, and the unabsorbed part the diluent. W^e have chosen the latter method as being tho most convenient and easy of manipulation, and it possesses the advantage that both pyro and caustic potash are well known to, and most probably on the shelves of all practical nhotographers. We have bought a Hempel's apparatus to show how oxygen would be analysed in a chemical lahorat iry if the greatest accuracy were not needed, and also a modiScation dttsigned for the use of lanternists. The IIempki. Method. The Ilempel consists of two parts — the one the measuring apparatus, and the other the absorption bulbs. The former coa.-ists simply of two glass tubes about three-quarters of an inch in diameter aod eighteen inches long, connected together at their lower ends by india- rubber tubing. One tube is open at the top, and the otiier is closed by a glass stopcock and gradua'ed. To start an analysis, tho graduated tube is filled completely ivith water ; whju conne.xion has been made with a supply of gas, tlii stopcock is opened, and as much gas as necessary is introduced ; tli i communication is then cut off, and the level is made the same in both tubes and the volume read. The object of making the level of the water in both the s.ime is to avoid reducing to constant pressure. The graduated tube is then connected by means of capillary tubes to the absorption apparatus, which consists of two bulbs, joined together, one terminating in a capillary I' tube. The bulb nearest the graduated tube, is filled with a solution of pyro and caustic potash in water. All th^ capillary connecting tubes and indiarubber tubes must, be filled with water in order to eliminate errors. The following is the best propor-* tion of pyro and caustic potash for the absorbing solution : — Pyro 1 ounce. Caustic potash 24 ounces. Water 20 „ The gas under analysis,. after Ij.'ing passed into tho bulb, is brought into intimate and renewed contact with the alkaline pyro by constant shaking, three to five minutes being generally sulRiuent. Tho gas is then dr.iwn back into the burette, and again measured as before ; the decrease in volume represents the amount of oxygen in the gas. In order to make sure that no oxygen is left unabsorbed, it is again passed into the pipette, and if there is no decrease in volume on again, measuring, the analysis is complete. .■\. Stmi'le Plan of Estimation. The other piece of apparatus we have here is of very simple con- struction, and could be procured at a small cost; or, if you have practised gla^s-blowing from the practical lessons given you by one of us, j'ou could easily make it for yourselves. It consists of a tube, three-quarters of an inch in diameter, eighteen to twenty inches long, and drawn out at each end. To each end is attached a short length of indiarubber tubing, provided with a pinchcnck. Beyond the lower pinchcock is another piece of glass tubing, which enables the tube of large diameter to be connected to a funnel, or other containing vessel, by means of indiarubber tubing of suitable size. In order to use it, the tube is first cooipletely filled with water 40 THE BRITISH JOURNAL OF PHOTOGRAPHY, [January 20, 1893 Connexion is then made with the vessel containing the gas to be analysed. Both pinchcocks are pressed, the one to allow the gas to enter, and the other to allow the water to escape. The lower end might, with advantage, be plunged into a tumbler or beaker full of ■water- As soon as the tube is full of gas, both pinchcocks are allowed to close the tubes, and the supply of gas disconnected. The funnel, or other convenient vessel containing the supply of pyro solution, is now, by means of the indiarubber tubing, connected, making sure that the tubing is completely filled with liquid. The bottom pinch- cock is now opened, and if the reservoir of pyro be raised, a sufficient pressure will be obtained to force some of the pyro solution into the tube containing the gas to be tested. At once absorption of oxygen will commence ; and, in order to facilitate this by increasing the surface of the liquid, the tube may be tilted or shaken, the pinchcock being opened occasionally in order to prevent too great a reduction of pressure inside, and thus cause a probable leakage of air into the apparatus, but this danger can be removed if the indiarubber tubing is wired on. AVhen the absorption is complete, place the vessel of pyro, with the pinchcock open, so that the level of the liquid is the same in both tube and reservoir. The tube must either have been graduated before, or, if only a few measurements are to be made, and the operator does not care to go to that trouble, the volume of the tube can be ascertained by completely filling it and measuring the contents in an ordinarj* graduated measure, then turn the tube upside down and till with water up to the mark occupied by the unabsorbed gas. The percentage of diluent can be easily obtained by dividing the Volum« of the residue in drachms or cubic centimetres by the original Tolume and multiplying by 100. Thus, suppose the volume of the unabsorbed gas to be 1" drachms or c.c, and the volume of gas operated on ^0 drachms tir c.c, then the percentage of diluent will be il X 100 = 1700 -^ 80 = 21 -So. There are one or two precautions to be observed in using pyro and potash. First, it is no use to try and absorb oxygen with a weak Molution of pyro ; it must be about the strength given above. Secondly, it must not be used too often, or left exposed to the atmosphere, as after a time it begins to give otT carbon monoxide, which would teriously vitiate the result of the analysis. Rr.SOLTS OF A.VALYSES. Hie results of the analyses of various samples of oxygen, which faave been obtained during the last fortnight are as follows : — N°;„ 0°; No. 1 15o 84 5°1 No. 2 39-4 .... 60-0 | No. 3 . . . . -IS'l .... .j6 9 J> Same maker at ditTerent times. No. 4 4^1-8 •■;6-2 I No. ."J 2r>-4 74-6 J No. C 7'0 93-0 Another maker. 7\o. 7 3-8 96-2 Made from chlorate and M.,0., at RN.C. for limelight. In conclusion, we hope that every one who uses a limelight, for whatever purpose it may be, will, if he wishes the light to be at its Tiesfc and constant, take the small amount of trouble that is necessary in order to master the few details, so as to enable him to test the gas «ent in, and, if it should contain more than a certain percentage of diluent, either return the gas as unsatisfactory or demand a reduction in the price, as, under these circumstances, not only is the article supplied bad, but apt to cause the user to acquire a bad reputation, which i« of far greater importance than the cost of the gas. We trust that the time will soon come when makers will guarantee that tbe percentage of purity is between certain limits, and then, if it is not, a remedy can be easily obtained. Salts of the precious metals are usually guaranteed of a certain percentage of purity, and, if any one took the trouble to analyse them, and found tliey were not so, we think he would be perfectly justified in seeking redress in a law- court. To issue as oxygen a mixture of air an4 oxygen, so that it eonUiiB thirty or forty per cent, of an inert and flame-cooling gas, is no better than the act of a publican who adds water to his beer and dilates hi^ whisky below what is allowed by Act of Parliament, and «ells them as unadulterated. The one is certainly as much of a fraud OK is the other- F. B. Geu.ndy and A. Haddon. DISHES AND TRAYS. It is not an impossible task, the repair of a broken porcelain dish ; It mu.st he a small one indeed that is not worth the trouble. A careless operator broke clean off one corner, the spout of course, of a 24x20 dish; this was very satisfactorily repaired with " coa^ulme." The parts should be carefully cleansed and hot, the hot cement applied to the edges, the latter then brought together, and while so held a second pair of hands may attach strips of gummed paper along the line of fracture ; the paper, contracting as it dries, holds the piece very firmly at the most critical period, iJurm;/ the drying nj the cement. To make the repair more certain and reliable and to prevent a mishap during use, the outside of the dish was at this corner taking in a good four inches outside the breakage, covered with a piece of stout linen, the same being applied with a strong solution of shellac in methylated spirit. The dish has, since this repair was effected, gone through some eight years of use. For a breakage right across I should still use coaguline carefully, applied hot, the edges to be held with gummed paper. By the time union is considered perfect we can consider what best to do to make assurance doubly sure. If the dish were lo x 12 or so, I should apply broad tape saturated with the shellac over the outside bottom and sides of the dish, putting it on in the •■ame way as upholsterers affix the broad tapes to the seats of chairs, then all round outside, covering the endf of the cross pieces with a long strip of tape. I rather think this would hold the thing together. If prefen-ed, we can, after cementing the pieces and bringing them together and drying, get made a shallow wooden tray, well put together at the corners, and big enough to hold the tray with a space of half an inch or so all round. Give it a good coating of the shellac varnish, and, when this is dry, mix plaster of Paris to a creamy consistence with water, adding the plaster to the water. As this stuff sets very quickly, we must make a rough estimate of the quantity required in order not to run short. The creamy plaster is run into the wooden tray, which it should cover to the depth of at least an inch ; now lower the dish into the tray, one side or end a little in advance of the other, and, if enough of plaster has been mixed, the sides and ends will be comfort- ably filled, any excess running over, the plaster to be nicely bevelled off, and the whole allowed to set and get thoroughly hard. When quite set (and if made hot) it will be well to apply a good coating of the shellac varnish ; the plaster, if dry, will absorb a good lot of this, and will be all the better for it. On one occasion, while repairing a rather small dish in this way, I well soaped the bottom of the di\f>. 42 THE BRITISH JOURNAL OF PHOTOGRAPHY. [January 20, ISO.T breaks up, not merely by the action of lig-ht, but by fhn application of ain' form of ener(ry. The part played by moisture in chlorine reactions is somewhat remarkable. It has been lately stated that absolutely dry chlorine has no action upon copper foil. As soon as a trace of moisture is introduced, energetic action sets in. M. Carey Lba. AMIDOL. [Putney Photographic Society.] Thuiwiiay, .January 12.— Mr. L. E. Morgan, representing Messrs. Fuerst Bros., gave a lecture and demonstration on Develojinwiit with Amidol. In a short preface Mr. Morgan claimed for amidol the following important advantages : — tiood keeping qualities in its dry state, ready solubility, cleanliness during manipulation, great energy in bringing out detail with- out the addition of free alkali, power to give the necessary density, and absence of stain, even in prolonged development. Comparing amidol with other developers, he said that exjierieneed workers might perhaps be prejudiced against it, as practically being a one-solution developer; they miglat think they were sacrificing some of the power which they possessed in older developers of readily modifying the proportions of the constituent parts to meet the requirements of varying subjects and of over or under-exposure. He would, however, prove that amidol also was quite capable of sucli modification — ia cases of over-exposure, by using a weak sokition and an extra quantity of bromide ; for under-exposure, a strong solution and only a small quantity of the bromide. For uncertain exposures it was desirable to begin with a weak developer, and gradually increase the strength as occasion required. The ordinary stock solution (2 per cent.) is made up as follows : — Amidol 10 grains. Sodium sulphite, cryst 100 ,, Water 1 ounce. This solution will keep well in full bottles, well corked, and although after a time it may discolour, it does not lose its developing power to any extent, nor does it stain the negatives or prints in any way. For use, dilute the stock solution with three to four times its bulk of water, 5 to 20 drops of a 10 per cent. Kolution of bromide of potassium being added tor each ounce of stock solution. This diluted solution may be used successively four or five times without losing developing power to any extent. For his own >ise Mr. Morgan preferred to keep the follow- ing stock solution, which will keep for any length of time : — Sodium sulphite, cryst 1 ounce. Water 20 ounces. For use, 8 to 10 grains of amidol powder, and a few drops of potassium bromide 1 1 : 10) are added to 4 ounces of the above solution. Mr. Morgan then proceeded to develop a negative which liad purposely been given a somewhat short exposure, using the ordinary strength of developer : the image appeared in about thirty seconds, showing full detail in that time, development being allowed to proceed. The necessary density was obtained in about three minutes ; the result w,is a brdliant • and soft negative of a good printing quality. As showing the capability of amidol for developing bromide paper, he exposed a piece under a land- scape negative and proceeded to develop with a solution of the same strength as that used for the negative. In this case also the result was extremely satisfactory, tlie tone of the print being veiy like a good platinotjpe. No clearing bath was necessary, and the 'manipulation throughout of the simplest. To prove that amidol is really a good all- round developer, Mr. Morgan proceeded to expose two lantern plates, giving the one tin exposure of one minute, and the other six minutes! still using the same strength of developer, but in the latter case with an additional quantity of bromide he produced two very brilliant and satis- factory slides. It was apparent as the demonstration proceeded that the members were agreeably surprised at the powers of amidol, particularly as the experiences of some of them with other developers recently introduced with great flourish of trumpets were of a disappointing nature, only confirming them in their preference for their old and tried friend,' pyro. Sfr. Morgan brought several bromide prints for inspection, but a portrait of a native of Morocco, a very fine enlargement by Mr. (iorin, and developed by him with amidol, showed most strongly that good results can be obtained with it without previous experience by an amateur, this having been Mr. Gorin's first attempt with the new developer. A hearty vote of thanks to Mr. Morgan concluded an enjoyable and mstructive evening. [Kemini; ton ami Bajswatcr Photoffmphic Soiioty.] Monday, January If..— Mr. Morgan gave a demonstration on develop- ment of negatives, bromide paper, and lantern slides, by that chemical He showed bromide prints from one negative which liad received ex- posures varying from one minute to ten minutes, each of which was considered a good print. The leading points he claimed for this developer are its freedom from producing stain, when dissolved, either upon the Hands or tlie plate or paper, though the crystals themselves, if allowed to remain in contact with the hands, will produce a brown stain Mr H. K. Davis (of the Camera Club), who has lar^^ely experimented with the new developer, especially for lantern slides, gave his new formula for development (for warm tones only). He stated that he considered the ordinary formula used for the development of lantern plates by amidol made a too active developer, veiling the plate before development was complete. His practice is to use a struiii/ developer irdl rrntrabied. Thus : — Amidol 160 grains. Metabisulphite of potassium 2 ounces. Water up to 20 „ This is the stock solution. Of this take half an ounce, and add to it 1 ounce of a 10 per cent, solution of bromide of ammonium, and water up to 2.j ounces, then add a quarter of an ounce of a 10 per cent, solution of carbonate of potassium. This will develop twelve or fourteen lantern plates. The following are the official instructions for the use of amidol : — I. — Concentrated Stock Snluiioii. Water 7 ounces. Sodium sulphite, cryst., pure IJ ,, Amidol 60 grai ns. May be kept for a long time in full bottles well corked. For use, mix one ounce of this concentrated solution with three ounces of water, and according to the make of the plates, add a small quantity, at most twenty drops, of potassium bromide (1 : 10). In this state the solution may be used four or five times successively, without muihlossof developing power, hut it is not advisable to leave the developer standing too long, nor to prepare more of it than necessary for the work in hand. For landscapes, or strongly lighted subjects, the developer may he employed in a still more diluted form. II. — Twd-Solulion Developer. Water 20 ounces. Sodium sulphite, cryst., pure 1 ounce. This solution will keep for any length of time. For use, eight to ten grains of amidol powder, and a few drops of potassium bromi :le (1 : 10) are added to four ounces of the above solution. To be saved the trouble of frequent weighings, keep a little horn or bone spoon for measuring the required quantity of amidol. To retard develop- ment, use a ten per cent, solution of bromide, and to accelerate it add a twenty per cent, solution of sodium sulphite. On very hot days, or for plutes inclined to fog, it is recommended to add a few drops of citric acid (1:10). With normal expo.^^ures the image should appear in from eight to ten seconds, and be fully developed in about four minutes. Over- exposure is recognised by the immediate .appearance of the picture, in all its details, as soon as the developer is applied, the deep shadows becoming veiled, and all more or less fogged. For over-exposure it is necessary to use a weak developer, and to increase very largely the quantity of bromide, using, in extreme cases, even up to one-quarter bulk of the amidol solu- tion. In every case of unknown exposure it is advisable to begin with a weak developer, or one which has done duty before, and increase the strength, when, from first indications, it is found safe to do so. For under-exposures, a strong developer, or a large addition of the sulphite is recommended, and these also help to give greater density, which end may likewise be secured by prolonging the development. The degree of intensity is best judged of by transmitted light, remembering always to make allowance for reduction in the fixing process. III. — Siieriiil Derclopev-I. Solution A. Water 20 ounces. Potassium meiabisulphite 2 ,, Amidol 1 ounce. This solution will keep for a very long time if well corked. Solution U. Water 20 canoes. Soda crystals 2 „ Solution C. Water 20 ounces. Sodium sulphite, cryst., pure i „ Eesults similar to pyro may he obtained with Solution A 10 parts. B 6 10 „ Water 70 ,, Bromide (1 ; 10) 3 „ But this formula may he considerably modified, according to require- ments ; it is not, however, advisable to increase the quantity of alkali, for fear of induciug fog. For over-exposed plates, add the solution B in the above formula lilt'e by little, umil the desired effect is obtained, never exceeding the amount above prescribed. Images of a softer chavjcter are obtained as follows : — Solution A 10 parts. B 20-10 „ Water 70 ,, Bromide (1 : 10) J-J part. Janufvry :.'0, 1893] THE BRITISH JOIKNAL OK I'lIOTOGRAPHY. 43 IV. — Separate Dercloper. Solution D. Water 20 ounces. Sodium sulphite, pure cryst i| ounce. Amidol 2 ounces. Tliix solution keeps colourless for a long time in full and air-tiglit ossels. When opened it goes from yellow to red. which, however, do.s lot iiflect the developing power, or colouration of plates. Solution C. Water 20 dunces. Sodium sulphite, pure cryst 4 „ For use take — Solution D o parts. Water 50-70 ,, Solution C 20-30 „ Bromide (1:10) IJ ,r This formula also has the advantage, by gradually adding solution C, f controlling development np to the point desired, which is specially im- I ortant for over-exposed plates. As the image loses on fixing it is recommended to "develop more (rongly. For Bromide Paper, l'>oth for prints and enlargements either of the above formula' may be wsed, and the freedom from stains will prove of great advantage. With diluted solutions clear grey tones are obtained. For Chloride Platen and Lantern Slides. Transparencies of the blackest tones are developed with : — Water 20 ounces. Sodium sulphite, oryst., pure 1 ounce. Amidol 40grains. W^armer tones are obtained through longer exposure and the liberal addition of bromide, even up to one ounce in the four ounce developer. ^ — . . THE WEST KENT AM.\TEUR PHOTOGRAPHIC SOCIETY'S EXHIBITION. This Society held its first Exhibition (members' work only) on Thursday I'ith, at the Public Hall, Sidcup. The President, Mr. Andrew Pringle, opened the Exhibition with a short address. Mrs. I'ringle then pre- senied medals to winners. Class A — Lantern slides, set of twelve. Any subject. President's silver medal, E. .J. Crowe ; bronze, Gregor Grant. Class B — Enlargements. Vice-President's silver medal, E. Hawkins ; Society's bronze, C. J. Crowe ; diploma, G. I. Gill. There were a large number of entries in this class, and a very tough contest. Class C — Set of four prints. Society's silver medal, E. Hawkins ; bronze, Gregor Grant. K. H. Pickell was awarded an extra special diploma for photo- graph of lightning flash taken June last. Class D — Not sufBcient entries for an award. E. Hawkins very highly commended. The Judges were Messrs. Cembrano, Pringle, and Uresse'r. The programme of the even- ing consisted of a good selection of music, with lantern shows at intervals. Slides by Messrs. Carpenter, Kdgar Lee, Pringle, Dresser, and members, were shown and much appreciated by audience. ENLARGING APPARATUS AND THE ILLU.MINANTS FOE SAME. At the Manchester Photographic Society, on January 12, the President (Mr. Heywood) in the chair, Mr. H. M. Whitefield gave an address on Eulanjiiiri Apparatus and the IlluiiiinantH for same. At the outset he remarked that most of what he had to give the meeting had appeared from time to time in Thk British Jouhnal oi' Photook.^pht, a source Id which nearly all things photographic could be found. Assuming that daylight was generally not available to the bulk of amateurs, his remarks would be confined to artificial lighting of the negative. He passed in review the various methods suggested to obtain this object, most of which he had tried. The plans to obviate the employment of condensers, by rows of gas jets, magnesium wire, diffusion of the light by opal or ground glass, itc, he considered unsatisfactory, as not giving evenness of illumination, and gave uncertainty of exposure. The threo- wick lamp, used with a condensing lens, was also faulty for the same leasoiis. He considered the limelight the best, both for enlarging and reducing ; ; but, for those who did not care to go in for this illuminant, he highly I recommended the " albo-carbon " gaslight, as advocated by Mr. Traill • Taylor some years ago. This was an inventioa to increase the illumi- nating power of gas for ordinary lighting purposes, and in its simple form consisted of a reservoir above the burner containing a supply of naphtha- ► line, over which the gas passed before reaching the burner, taking up the [vapour from the naphthaline, which was very slowly evaporated by the flame of the light itself, the recult being a Hmall bright light. To atlapt this for working in an enlarging lantern, he added a second burner, placing the two jots one behind the other, with the flat sides towardit the condenser. The flames mu.st be separated just auflicicnt to prevent them joining. This arrangement gave a more solid light than a Ringle burner. The whole of the flame was not required, and be enclosed the burners in a tin box having suitable air inlets at the bottom and a dark chimney at the top, a circular aperture, about three-quarters of an inch in diameter, being made opposite the brightest part of the flame and covered with a piece of glass. He found that the albo-carbon light was very actinic, and the difference in the exposure of a print as compared with that by the limelight was not as great as many might suppose (experiments given showed the advantage of the naphthaline very markedly), and the use of the light no more trouble than an ordinary gaslight. Mr. Whitefield showed his enlarging lantern, which differed little from the usual form, and explained the necessity of having a condenser large enough to include the whole of negative without using the extreme edges of the lens, and practically demonstrated the working of the lights. RECENT PATENTS. APPLICATIONS FOR PATENTS. No. 468.—'' Improvements in J-ighting Apparatus for use in Photography." S. 0. Tatloh — Dated Jamiary 10, I8y:3. No. 014.—" Improvements in Photographic Dark Slides.'' .S. J. Levi, A J. Jones, aiul E. Hoi.mks.— /tal>\M>Ms,&.~hatcd January 12, 1893. No. 741. — "Improvements in and Apparatus for the Manufacture of Films especially intended ibr the Production ot Trausp.ireiit Films for Photographic pur|.oses." W. H. Walkkr.— Aate/ January 12, 'idm. PATENTS COMPLETED. Improvements in Appahatus for C'HAXGiXfi anu FoctrssiNu and Exi-osinq Photographic Plates ok Films. No. 3680. Thomas Edwaiid Heath, Oakbridge, North-road, Cardifl'.— December 10, 1892. This invention is intended principally to be used for that class of lamera known as hand cameras, but it may "be used for others. It enables a large nninberof plates to he carried in a very small camer.i, and the plate^ to be seleet?;ase plate, which is pierced with a slot so shajied as freely to admit a sensitive plate. The sides and top of the exposing frame are grooved, so as to allow the plate to slide freely in and to bold it approximately in position. The base plate travels in suitable grooves, which extend from end to end on either side at the bottom of the exposing chamber. To tlie base plate I attach, at the front and at the back, binds of leather or other suitable material which may be stitl'ened by narrow strips of wood. These leatlier bands extend to the grooves on either side of the exjiosing chamber, and slide in them so that all light from the exposing chamber is excluded from the lower half of the camera box. In the lower part of the camera, and extending from very nearly under the baek of the lens to nearly to the plane of eqnivalent focus, I have a store box, which is grooves at the front end of the chamber in which the said plates are placed. The plates are pressed forwards towards the stops by a spring, Init the slots in the said stops are so placed that the projections upon the frames cannot pass therethrough until the plates are .sliifted to the required position. In order to effect this movement of the frames carrying the plates, we provide a slide of the same thickness as the plates, and designed to be operated from the exterior of the apparatus. When one of the frames is moved by this slide to bring its projections oppo- site to the slots, the spring presses the series of plates forward, the front plate falling into a receptacle designed to receive it. Onr improvements in lens shutters comjirise a sliding frame carrying the plate cr diajihragm for closing the aperture of the lens. This sliding frame is normally retained with the shutter in a closed jiosition by means of a spring, and is opened for the exjiosure of a plate by means of a rotating cam operated by clock mechanism, and arranged in conjunction with an escapement in such a manner that when the cam is relea.sed by the escapement it will make half a revolution to open the shutter, the closing thereof being effected by the spring. In conjunction with the cam. we provide a stop which serves to arrest the rotation of the cam when the shutter is open in order to enable the said shutter to be used for time exjjosures. Improved Altojutic Lock or Sprls-q Catch for Folding Camera Tripod Stands. No. 3226. Alexanukb Birnie. 118, Perth-road, Dundee, Forfar, N.B.— December 17, 1892. This invention relates to folding tripod stands for camera", its object being to retain the parts of each leg securely ami firmly in position when unfolded for use, and also to allow of the said legs being readily folded up when desired. In carrying out iny invention I employ an automatic lock or spring catch, consisting essentially of a cross bar in combination with or part of a bent spring of suitable design, tlie whole being fixed to one section of the leg of the tripod stand. On tlie other ami adjacent section of the leg is fixed a cross bar, witli a recess for receiving the releasing knob of the spring when the two parts of the leg are unfolded — that is to say placed in line— the remainder of the spring, when it has passed the recess, springing out and catching the said cross bar. IMPR0VE.MENTS IN Bl'RXEP.S OR JETS FOR THE LiMELIGHT. No. 18,836. James Edward Andkrsox, 9, Crawfonl-passage, Farringdou- road, and Alfred Wrench, 50, Gray's Inn-road. — iMcembcr 17, 1892. This invention relates to biirners of the kind used in magic lanterns for the production of the limelight. Such burners as hitherto usually constructed are providcil with a spindle, upon which the block of lime used with the burner is adapted, to be raised and also rotated, and in some cases such burners are adapted to be adjusted bodily both vertically and laterally rela- tively to the socket, by means of which the burner is supported upon the supporting jiillar, thereby avoiding the necessity of moving the said socket relatively to the pillar. The means heretofore adopted for adjusting the burner relatively to the said socket have been defective, inasmuch as the vertical adjustment of the burner caused the spindle carrying the lime block to be moved more or less out of a vertical position. The object of this invention is to provide for effecting the adjustment of the burner without affecting the perpendicularity of tlie said spindle. In carrying out the said invention we eiiijdoy a socket adapted to be fixed to the pillar in the ordinary luaiuier, and having its upper end screw-threaded and provided with a nut. The burner projier is carried by a second socket, which .slides upon the first-mentioned socket, and is acted upon l)y the said nut, a spring lieing placed between the second socket and the fixed socket in such a manner that when the nut is turned in one direction the burner will be moved downwards against the jiressure of the said spring, and that when moved in the leverse direction the spring will raise the burner to keep the second socket in contact with the nut. To ett'ect the lateral movements of the burner, the rear side of a collar upon the second socket is provided with gear-teeth, with which a pinion carried in bearings upon the fixed socket is designed to engage, the said pinion having a knob or handle for operating it. MEETINGS OF SOCIETIES FOR NEXT WEEK. Date of Meeting, January 23 .... 2.3 .... 23 .... 23 .... 23 .... 23 .... 24 .... 24 .... 24 .... ;; i4 :::: ,. 25 .... „ 25 26 .... 25 .... 25 ... 26 .. 26 ... 26 .... 26 .... 26 .... 26 .... 26 .... )• 26 ., „ 27 ..., „ 27 .... „ 27 .... .. 27 .... „ 27 .... 27 .. 28 .... Name of Society. Camera Club Dundee Amateur Lantern Society North Middlesex Putney Uiclimond Birmingham Photo. Society Great Britain (Technical) .. Hackney N e wcastle-on-Tyne & N .Counties Paisley Bath Burnley Phot(^raphic Club Southport Stockport Camera Club Glossop Dale Hali fax Photo. Club Hnll Ireland Liverpool Amateur London and Provincial Oldham Cardiff Croydon Microscopical Holborn Maidstone Swansea West London Hull Place o! Meeting. Charing: Cross-road, W-C. Asso. Stndio, Nethergate, Dnndee. 20, Hanover-.square. Jubilee Hou.so, Hornsey-road, N. Boys' Gyinna^inm,Charlwood-roa(l. (ireyhound Hotel. Club Room, Colonnade Hotel. 50, Great Kussell-st., Bloomsbury. 206, Mare-street, Hackney. Central Exchau^je Art Gallery. ^, G an 7,0- street. Paisley. Roy. Lit. &;Sc. Inst., Terrace-walks. Bank Chambers, Harffreaves-street. Anderton's Hotel, Pleet-street, K.C, The Studio, 15, Cambridge-arcade. Mechanics* In.stitute, Stockport. Cbariiig Cross-road, AV.C. Mechanics' Hall, Halifax. 71, Prop pec t. street, Hull. Rooms, 15, Dawson-street. Dublin. Percy-buildings, Eberlf>-street, f'hampion Hotel, 15, Alders^ate-st The Lyceum, Union-street, Oldham. Public Hall.Goorge-street, Croydon, "The Palace," Maidstone. Tenby Hotel, Swansea. Ohiswiek School of Art. Chiswick, 71, Prospect-street, Hull. T.ONDON AND PROVINCIAL PHOTOGRAPHIC ASSOCIATION. January 12, — Mr. J. Hay Taylor in the chair. ANiiLK OF View, Mr. P. EvEKiTT criticised the rule lor finding the angle of view included on: a given sized plate which Mr. Haddon states in an article appearing in the current Almanac. The rule is, with a given plate, to take its longest dimension^ divide it by the focus of the lens, seek the corresponding or the nearest corre- sponding tangent, read off the arc, double, and that will give the angle in- cluded on the plate. He (Mr. Everitt) thought that Mr. A. Haddon was not altogether correct, as the angle would be determined by the centre of vision on the plate. Mr. Haddon should have taken the point of intersection nearer the margin. According to his (Mr. Everitt's) idea the rule should be to measure the Jurthcst focus from the optical centre, divide by the focus of the lens, and then seek the nearest tangent and read off. Mr. W. E. Dkbenham pointed out that the angle varied with the position of the plate in relation to the axis of the lens, hence he thought both Mr. Everitt and Mr. Haddon right. January 20, 1803] THE BIUTISII JOURNAL OF PHOTOGRAPHY. Mr. HaDdon iimiiitainml that the rule be had given was the correct one, anil after some l'\irtlier diaciission the subject dropped on the understanding that it would be Iirought up again. The Rstim.vtios ok Oxyoen Gas. Mr. H.MWON read a paper, by himself and Mr. Grundy (of the Koyal Xaval College, (Jreenwieh), on this subieot (.see page 3i>). At its conclusion, Mr. Haddon remarked, in reference to the tibulatcd percentages given, that, if one took oxygen diluted with only five percent, of oxygen andmixedit with its own volumeof atmospheric air, a result would be nbtaiued ju.st about the me.in of No". "J, 3, ai;d 1 in the table. A practical denion.stration by the llempel !iiethod, .as described in the paper, w;is then given, the parople of oxyjjeu tested being found to contain fj-!' per cent, of nitrogen, the O-vygen being considered a very good sample. .Vnother samjile was then tested by the secoHfl method deserilied in the paper, and found t. Mr. Huerhaps by any other means, he e.xhorted! the Society to use to the full its power of educating those who had not the means of educating themselves by extensive free exhibitions of pictures, and by widened enterprise in connexion with the lantern entertainments. The following gentlemen were elected olficers and members of the Council for 18SI3 •.—Premlcnl: Sir J. B. Stone, J. P., F.G.S., V. ll.G.S.— Viu-t'residents : Messrs. J. J. Button, .1. T. Mousley, J. H. Pickard, W. Jones. — Council : Messrs. F. S. Goofle. A, R. '..ongmore, E. Underwood, A, J. Lee.son, Geo. Tliomason, G. B. Miller T. Taylor, E. C. Middleton.— Trert-sKi-er; Mr. W. Rooke. — Lihi-anwn. : Mr. W. S. Horton. — Ihm. Secretary: Mr. James Sim- kins. — Assistant Secrttaii/ : Mr. Ernest Winn. Bristol and West of England Photographic Association.— January 13, Annual Meeting. — Mr. H. .\. Hood Daniel was re-elected President ; Colonel Playfair and Mr. Ed. lirightman, Vice-Presidents : Mr. F. Bligh Bond, Secre- tary, with Mr. H. A. Hutchin.son as Assistant Secretjiry ; and Mr. W. Molineas Treasurer. The existing members of the Council were re-elected. Shropshire Camera Club.— January 11, Annual General Meeting.— The following officers were appointed: — J'resiileHt : Mr. W. W. Naunton. — Vice- Presidents : Messrs. .1. R. Greatorex, G. Bidlake, W. S. Buddicom, M. J. Harding.— C'ownc/V ; Messrs. W. Alltree, W. Bowdler, Dr. Cureton, S. L. Delia Porta, R. .1. Irwin, W. G. Preecc, I. Pyefinch, F. W. Williams.— Treasurer. ' Mr. W. Barson. — Hon. Secretary : Mr. Martin J.Harding. — Assia 40 THE BRITISH JOURNAL OF PHOTOGRAPHY. [January 20, 1893 lani Secrrlar)/ r Mr. W. Heath. A special vote of thauks was passed to Mr. Xaiinton for his valuable services as Secretary since the formation of tlie Cliili, and to Mr. Irwin for his services as lanternist. A Sub-committee was ap- pointed to consider a scheme for acquiring permanent Club rooms, including dark room, and five new members were elected. The meeting was adjourned to the "2iith inst. for the purpose of revising rules, &c. I Carrcspmimts should tu-vcr ivrite on hoth'sidcs of the impcr. No notice is taken of comvtunication^ unless tlie names and adrf>-t?.ss(?s of the v:riters are giwn, HALATION, DOUBLE FILMS, AND CHROMATE OF SILVEE. To the Editor. Sir,— I have to thank Mr. Gregor Grant for his reference to Mr. W. K. Barton's article in the Ai,5iak.\c for 1888, which I find pretty well corroborates what I have already said. My own recollection of Burton's experiments with ohromate of silver is that they date much further back ; but I cannot at the present moment refer to them, but the article alluded to will for the present sutEce. In that article Mr. Burton himself says his experiments with chromate of silver as a preventive of halation " did not succeed," the chromate being rednoed by the developer ; and then proceeds to make what I believe to be merely a suggestion as to a method by which this result may be avoided, namely, soaking the plate before development in a weak solution of bromide of potassium. I conceive it to be a suggestion merely, for two reasons : first, because no actual statement is made that the experiment has been made ; and secondly, because, if it had, the result seems scarcely likely to be any more of a practical success than before, though from a different reason. Mr. Burton seems to have overlooked the fact of which he, of all men, is perfectly aware — the fact I alluded to in my previous communica- tion as having been just pointed out by Captain Abney, that the soluble chromates destroy the effect produced by the action of light upon a sensitive film. If we imagine such a duplex film as that alluded to by Mr. Burton and Mr. Grant, silver bromide upon silver chromate, to liave been exposed to light, we can readily believe that it will have an image impressed upon it ; but it is not so easy to see how that image is to be developed, even by Mr. Burton's plan. The immersion in solution of potassium bromide will certainly convert the substratum of chromate into silver bromide ; but, at the same time, it will, by double decomposition, form potassium chromate, which cannot but have full access to the over- lying film of bromide of silver. What, then, about the image ? It is true that the bichromate is far more powerful in its destructive action on the latent image than the neutral chromate, on account of the loose atom of chromic acid, and it would be the neutral chromate that is formed under such circumstances. But the latter salt alone, and more particularly in the presence of a soluble bromide, is quite powerful enough to destroy any image with which it may be brought into contact. I should not like to say that it is impossible to obtain any sort of image by development under such conditions, but it seems quite impossible that a practically useful one could result. By using a very weak solution of bromide, and a great volume of it, so that the chromate would be con- verted slowly and a little at a time, the bromide film would be submitted practically to the action of a very feeble solution of potassium chromate, which might possibly not exert the full effect. One other point I may note in pas.=ing. If the chromate film referred to by Mr. Burton is made in the same manner as that he recommends in another place as a substitute for ruby glass, namely, by adding silver nitrate and potassium bichromate to solution of gelatine to form an emulsion, from which the soluble matter is not subsequently washed, I am afraid there would be still further reason for failure. Even supposing the equivalent proportions of the two salts are so. exactly hit that there is no excess of either, there would still be a soluble silver salt present in the form of dissolved chromate of silver. When the two salts just men- tioned are mixed, neutral chromate of silver is formed together with nitrate of potash, and nitric acid is set free ; and this latter dissolves a small quantity of the silver chromate. The experiment is easily made of adding silver nitrate in excess to solution of potassium bichromate, when, after the precipitate has subsided, the supernatant solution will be found to be higlily coloured. A drop of the chromate solution will give a further precipitate of silver chromate, showing tliat the colour does not come from excess of that, but it the supernatant liquid is poured off, and treated with a solution of carbonate of soda until no further precipitate occurs, it will be decolourised, and the red precipitate will show that the colouration was due to chromate of silver held in solution by the liberated nitric acid. It such a film were treated with an alkaline, or, indeed, any developer, it is not difficult to believe that reduction would occur without any question of exposure, and that may explain the first of Mr. Burton's failures, but does not affect the general question of the practicability of the plan suggested. If any of the -eaders of the Journal are desirous of testing this plan, he best way to proceed is to employ the neutral chromate of potassium in conjunction with nitrate of silver, the former slightly in excess, and to wash the emulsion so formed. Or carbonate of silver may be emulsified in the usual way — by precipitation and decantation before adding the gelatine — and then converting by means of chromic acid or bichromate of potash. A still better plan was published by M. Paul Eoy, of Algiers, some ten or twelve years ago for forming an emulsion of pure chromate of silver. It is based upon an alleged action of the soluble chromate in excess to precipitate gelatine in conjunction with chromate of silver. The process consists in dissolving one part of gelatine in 100 parts of water, to which ten parts of silver nitrate are subsequently added. When this is dissolved, a saturated solution of ammonium or potassium bicliromate is added with vigorous stirring ; the first result is of course the formation of chromate of silver, and when the soluble chromate is in excess, the gelatine in com- bination with the silver salt is said to separate, and may be washed and redissolved by heat. I fully agree with what Mr. Burton says in the article I have referred to in regard to the probability of chromate of silver being found eventually to be a useful photographic salt. But I am afraid we shall have to find an altogether new developer first. It was far from my intention to criticise Mr. Gregor Grant in a carping manner. My allusion to the impossibility of getting clear shadows with the double films was aimed at the theory propounded rather than the plates, and I must adhere to the belief that if such a " proper " exposure is to be given as to reverse the image of the more sensitive film, then there iiiiiHt be a deposit in the shadows. Again, when Mr. Grant says that Captain Abney was "the first person to lay down any law," &c., and "the theory just adrani-ed hij hint "—the italics are mine — was the reflection theory in fact, 1 naturally thought he meant it, and therefore gave the date of an earlier publication. Now, as he denies having stated that Captain Abney " was the first to discover or notice the causes of halation," I am in doubt as to how he came to be the first to " advance " them. Captain Abney has done a very great deal in connexion with the investigation of the various causes of halation, but, I repeat, Marlowe was the first to draw attention to refiection from the back surface as one of them. — I am, yours, '>n6sB, I nn my own account, at the address helow, make and use ^Manterna of the same kind. I may say that the Inntrrn Mr. .\rmBtront; refers to was made about two and a half years apo. There is not ninoh in the idea further than that the bottom lantern is ventilated at the side. All the above facts are well known to Mr. Armstrons, but it is wonderful wlint some folks will do for a little favour. Trusting you will see your way to coneet such mistakes, and feeling >ony to trouble you over such little aifairs, which are better corrected. - I am. yours, Ac, Jamks Mimik. 77, nenrielil-street, Gla^ioir, Janiiarii 10, IHttJi. THE BRITISU JOUKNAL OF I'HOTOGIiArilY. A VALUATION. To the EDrroK. Sill, -RespectinR the inquiry of your correspondent, "A Seaside I'hotosrapher," I should be disposed to say that, it there ore no other I on«iderations of weight beyond tho.se mentioned in his letter, the .siness would be cheap at lOOH/., and if bought at 1100!., the transaction ,i..uld be fair on both sides. — I am, yours. *c., K. S. V. 1'. rawiaty 17, 18".ta. -^•~ A BUSINESS MYSTEEY. To llir Emtok. Sill, — How do the enclosed assimilate ? I cut them out of two papers O'. last week. — I am, yours, &c.. Sceptical. .Tiuiiinvij 17, 189.S. [The following are the confiictinfr announcements to which our correspondent refers. — Ed.] From the Slocl.j'Orl AiUtrli'i-r, January (>. DAY AND ELKCTRIC LIGHT STUDIOS.— Mons. Sauvy (of Paris) has just returned from his usual visit to Palis, and w^as successful in procuring a FIRST-CLASS FRENCH ARTIST, who will attend to the customers, as well as himself personally as usual, from 10 a.m. to li p.m. daily. 22a, King-street, Manchester. From the Mniuheflfr CUij Xeirx, January 7. MRS. KATE HAR(iREAVi:S begs to intimate to the public that she has purchased the entire PHOTOGRAPHIC BUSINESS of Monsieur Sauvy. 22a, King-street, Manchester. All the eminent Artists formerly engaged have been retained. Mrs. Hargreaves can assure her patrons that the same high-class work will still be produced, and that the whole of the Negatives of Portraits taken at 22a, King-street are in her possession, and copies can be had at any time. Every branch of the business is under her personal super- vision. Mrs. Hargreaves draws particular attention to and invites inspection of her Speciality (recently introduced), viz., the highest class of (Jpal and Ivory Miniature Painting. THE WEEKLY HALF-HOLIDAY. To the Editor. Sii;, -The adoption of a weekly half-holiday, which has been occupying the attention of various trades for the past few years, is worthy the com-ideration of those engaged in the photographic business. When originating the movement in Glasgow and Paisley, we found that all the principal members of the profession aci-cded to the proposal, and strictly cairied it into practice. As the spring is drawing near, it is expedient for a successful issue that those concerned interest themselves on the mbject, and by their energies establish the movement, much to the Baiisfaction of those capable of recognising its advantages. — I am, yours, Ac, Bks.iamin R. F.u;i.KNEr.. 10, St. James-street, Vahleii. ■Tnnnnni 14, 1893. iSichanoc Column. Will i;xi^bansr(' 13L single lantern for a 12x10 camera.— Addresa, Feank Loblit» Ilanlijy, Staff.>rdshire. DHllratyer's in lens in excbanjre for ceiitorlev«»r pnlftrjfipff Inn*em. eiffht and a quarter iiuh coii(lcnsofs.--A(lf1rePS, A. Sim.mows. 'll-, ■\Vestmiiister Hfidjfe-road, S.K. Kxchaiiffo Thomtau - Pickard";* "Spwi.il" plintter, ixUo "Cyclist" tripod, for Wa*Ron's b:ilf-plnte tnru-table and tripod.— Addrei-s, T. Bkrsard, 101, Goldfaawk- road, W. 'Ex^'bangro six-inch Weston biimisher and laimor, backgrourdf', 12x10 camnra and ^lides, rtaff, Pnmihrej's telescopic staud. for anytbiag uteful.— Address, A. Hollis, harrow -in- Fnrness. W)K>!.\vicH PnoTO<:u.\PHic Society.— January 26, Lantern Xight. Wkst London Photographic SociKTV.—Jnnnary 24, The Itoyal Palaccx of Kitfjfand, illnstrateii by Ittiiterii. by Mi-. H. X. King. Pj|(»ti>(;rai'HIC Sof iktyok (;rkatBhitaj.\.— Technical Mcetin?', JnTinaTy24. «t U), (;rL'»t llnssL'U sti-cet, W.l". J'/totolil/iof/T^qiht/, a dLiiionstrutiou I-y Mr. \V. IC. l>ebcubain. anstoers to CTorrrspontients. *,* AH matters inteTuUd for the text pnrtinn of thi» Joi.'RSAL. inrhidinrf iliierirn anil Exchanges, mttat lie oililrensed to ' Thk Editor, Thk BbitIsM JoiRNAi, OK PHoTOdHAPRy," 2, York-street, C'orent (JarUen, London. In- attention to this ensures delay. *,* (ni respondents are in/ormed that i« cannot undertake to answer eom- mnnirations through the post. *,* Communicntirms relntinij to Advertisements and general business affairs sUniiU lie addre.tsed to Mensrs. Hknbt GwilurwooD & Co., 2, York-street, Covent Garden, London. .\. .). — .Me.s.sr3. Hurter :irt of the salt. 2. A view-finder, if constructed for the jmrpose. will show precisely what is to be seen on the ground glass. 3. There are no books published on such simple mutters. E. R. B."lf, instead of suspending the prints on a line to dry, they arc dried in a blotting-book, they will net curl u]i, and will he much more convenient for mounting. Greater distortion occurs from expansion, and the stretching of the paper in mounting, when the pictuies are mouute- se, is insensitive to light, or, at any I'ate, incapable of forming a visible image. The experiment is easily made witliout the trouble of forming an emulsion by floating paper upon a solution of nitrate of silver, and, after drying, refloat- ing on bichromate or, preferably, neutral chromate of potash, and subsequently washing very thoroughly to remove all excess of either salt. It is important that the paper in the first instance and the water used be free from soluble chlorides, otherwise chloride of silver will be formed, and may lead to false judgment. If the layer of chromate of silver be thoroughly freed from soluble matter, and be clear of silver haloids, the paper so prepared may be exposed under a nega- tive without producing any trace of an image. If, however, any traces of chromic salts remain in the paper^ more or less discolouration will occur, and, if an excess of silver should have been used, a similar result will accrue. So far we have only dealt with the capabilit}' of chromate of silver for forming a visibly or direct image ; let us now turn to the question of development. It is an easy matter to say that it is sensitive if we only knew how to develop tlie image formed ; but wliat we have particularly to deal with now is whether with our known methods of development it is possible to produce an image. So far, we have not found it possible. For the purpose of experiments made some years ago, and which we have repeated quite recently, an emulsion of pure silver chromate was prepared. In order to avoid as far as possible anj- secondary action that might arise from the action of silver salts or excess of cliromic salts on the gelatine, the enmlsion was made with jjrecipitated carbonate of silver con- verted into chromate by the cautious addition of a weak solu- tion of chromic acid, followed by washing in distilled water. For all practical purposes tlie film of chromate of silver thus obtained was as pure as could be. So far as actual trials were concerned the results were identical, and afforded no opportunity of varying the condi- tions under which they were made. With evei-y kind of developer used, including the most recently introduced, the chromate was blackened, whether exposed or not. Further than this, the same result followed the employment of plain Janimiy -27, 189.1] THE BRITISH JOUKNAL OF PHOTOGtlArHY. r,i solution of pyro, without any alkali whatever. In fact, chromate of silver is reduced without exposure to light by any of the developers in ordinary use. Acting on the suggestion originally made by Mr. Burton, lul rofen-ed to in the recent correspondence on the subject, the experiment was made of converting the chromate into bromide of silver before development, but with little better success. Before development the films were immersed in a solution of bromide of potassium of the strength of half a grain to the ounce until the red colour of the chromate was completely dis- charged, and the developer then applied in the ordinary way. The result was invariably the same, the film appeared abso- lutely insensitive, no matter what exposure was given, and it was only on the application of an abnormally strong solution — sufficient to produce fog — that any result in the way of develop inent could be obtained. It is, of course, possible that with other fonns of develop- ment— acid silver, for instance — a better result might be obtained ; but, looking at all the circumstances, we are scarcely encouraged to hope so. At any rate, for the present we may rest content that chromate of silver is of no practical use as a photographic agent. PHOTO-PLASTIGRAPHY. A FEW weeks since, it will be remembered, we devoted a de scriptive article to a new style of sculpturesque portraiture by an American artist. Although there is but a comparatively small demand for that class of picture in this country, there is, we believe, a greater demand for it in America, also in some parts of the Continent. Seeing that statuesque portraits are still being produced here as well as abroad, and that, notwith- standing their frequent incongruities, they meet with a certain degree of favour, it is not inopportune to consider whether or not genuine statuettes would not, at the present time, meet with commercial success if they were forthcoming. It will possibly be new to many of our readers to learn that veritable statuettes — bust and full-length — were produced com mercially by photographic means in the earlier days of photo graphy. The first process — that of Mr. Fran<;ois Willeme, of Paris — waspatented in this country just thirty years ago. We wellre member seeing at the time some really very fine examples of the work, alike in Parian, plaster of Paris, and bronze, that were made by the inventor himself, and also by the late Mr. Claudet, of Regent-street. Mr. Willeme's process was this : — The studio in which the negatives were taken was circular, and about thirty feet in diameter. In the centre was a raised polygonal platform with twenty-four faces, numbered con- secutively from one to twenty-four. In the centre of this platform the sitter was posed. Round the studio were placed twenty-four cameras, one exactly opposite each of the faces of the polygon. A negative was then taken, simultaneously, or as nearly so as possible, with each of the cameras on wet collodion, so that twenty-four different views of the sitter were obtained. The negatives were then numbered according to the face of the platform fi'om opposite which they were ob- tained. These negatives completed the actual photographic portion of the work. The statuette was made in the following manner : — On a block capable of being rotated on its axis was placed a cylinder of soft modelling clay. This block waspolygonal in shape, and its faces were numbered from one to twenty-four ; in fact, it ■was an exact counterpart in miniature of the platform on which the sitter was posed. At a certain distance from the clay was fixed a ground-glass screen, >ipon which the enlarged image of one of the negatives was projected by mean of an enlarging camera. One of the sides of the Iilock, whose number corre- sponded with that of the negative, was then brought opposite the image. The outlines of it were then gone over with the tracer of a pentagraph furnished with a cutting style or knife, which cut a corresjwnding outline in the clay. Then a second negative was taken, this time by preference one obtained at right angles or nearly so to the first, the clay being rotated to the corresponding number, so that the cut then made by the style would intersect that previously made, by which a wedge- shaped piece of clay was set free, and could then be removed. This operation was repeated with all the negatives in turn, so that in the end a perfect transcript of the contour of the sitter was obtained. All that now remained to be done to complete the statue was to touch out a few of the hollows and scrape away the trifling edges left between the various incisions made by the cutter of the pentagraph. Instead of projecting the image on to a ground-glass screen, it was sometimes thrown on to white paper or card, and the out- line then traced with pencil. This tracing was then used with the pentagraph instead of the grouud-gla'ss imago. When the clay model was obtained, any number of duplicates could be produced in plaster of Paris, Parian, or bronze in the ordinary way. As illustrating the practicability of the process, it may be mentioned that Mr. Willeme used to supply a full-length statuette, fifteen or eighteen inches high, for three hundred francs, equal to twelve pounds English. A couple of years after the date of Willi'me's patent Mr. Claudet patented another method of working. In this metiiod the pentagraph was dispensed with, the enlarged image being thrown direct upon the modelling clay, and then manipulated by hand. The clay was fixed on a rotating table, as in the process just referred to ; but it was capable of being moved back ward or forward by means of a slot, as required. Thin plates of metal were placed in the clay, upon which the outlines of the figure could be seen as the clay was cut away. Such are the brief outlines of, at least, two practical methods of producing sculptures by photography, and others will suggest themselves to the ingenious. At the time these processes were introduced only wet- collodion was in use for portraiture, and all familiar with its working know quite well the difficulty there would be in obtaining a couple of dozen negatives with long exposures from the different points of sight at the same time, particularly in hot weather, when the plates will only keep a few minutes after preparation. No such difficulties would be encountered with dry plates. Twenty-four cameras were formerly employed ; but if the platform upon which the sitter is placed were a turn- table, and he were posed on its axis, one camera could practically be made to answer the same end, provided it were rotated for the different views. Two cameras might, however, be found more convenient in practice. In this case they might be placed so that they were opposite alternate sections of the platform. The exposures could be made simultaneously by one operator with pneumatic shutters. The cameras would be fur- nished with repeating backs carrying, say, half a dozen quarter- plates each, so that two slides for each would suffice for the twenty-four negatives, supposing that number were required. Some portraitists, suffering from stagnation of business, often sigh for a novelty or new style in portraiture. Here is a style which, though it cannot in any way be termed new, would cer- 52 THE BRITISH JOURNAL OF PHOTOGRAPH!. [January 27, 1893 taiuly now be novel to the public generally, and it requires very little outlay for its practice in any ordinary studio. It may be said that photo-sculpture when introduced did not prove a commercial success. That is true, but the same may be said with regard to other things in connexion with photography on their first introduction, though they have proved successful later on. It may be well to mention that at the time photo- sculpture was introduced the carte-de-vidte furore was at about its full, and only small pictures that could be put in albums were entertained. As regards cost. Of course, statuette portraits cannot be produced so cheaply as paper pictures ; but there is no reason why a sculptured portrait should not be very profitably supplied for the same price as that usually charged in good establish- ments for well-finished enlargements, while duplicates could be supplied for infinitely less than duplicates of finished enlargements. The Proposed New Central Photographic Institu- tion.— We are informed that consideraUe progress has taken place ki the preliminary discussions necessitated by the suggested formation of a new broad-based photographic club or institute, several meetings of the originators having been held. At the present moment a very strong and representative committee, counting some of the foremost men in all departments of modern photography, is in process of com- pletion, of M-liich a meeting is to take place at an early date. We under.-tand that the attitude of the principal London Societies, and of large numbers of photographers, is distinctly favourable to the scheme. Photomicrographic Stereograms.— An alleged novelty in stereographic photographs was described by Dr. Ilausemann at a recent meeting of the Berlin Physiological Society : he stated that he had obtained photographs of microscopic objects which, when placed in a stereoscope, gave the impression of solidity. They were produced, he said, by taking one photograph of the ohject in focus for a given level, and then a second photograph at a different level, the two when united in the stereoscope giving the impression of solidity. This method, among several others, has long been employed by us in pro- ducing micro-stereo-photographs, and ought to be well known to attentive readers of this Journal, seeing that it has been published more than once. Absorption of the Sun's Xladiations. — Professor Langley and others have, during their investigations of the solar radiations, come to the conclusion that " the heat reaching us from any point of the sun's limb is only about half that reaching us from its centre ; but the Astronomer Royal for Ireland and Mr. W. E. Wilson have been engaged upon a farther investigation of the sun's rays, and have almost proved that the sun's own atmosphere absorbs fully one- third of the sun's heat. To fully sustain their argument, the two named astronomers suggest the use of photography. They would have photographs taken from time to time through an entire sunspot cycle, and all reditced in a precisely similar manner, from which deductions could bo drawn as to anv real change in the absorbing power of the sun's atmosphere, and change of condition in the sun's surface, which would he entirely lost in direct observations, owing to our atmosphere varying so continually in its optical properties. The XSclipse of April next. — M. de la Baume I'luvinel has made a commuDication to the Astronomical Society of France indicating the points he considers of most importance to be investi- gated|during the period of the shadov/ing. The ever increasing prominences, he says, can he studied any time, and therefore should be left alone, and the brief moments put to other uses. The corona is most important, and should he photographed to show^ its general aspect with various exposures; its spectrum also should be photo- graphed. Several plates should be used, as, owing to the various degrees of brightness of different parts of the corona, it will be im- possible to obtain all the details in one exposure. He recommends' isochromatic plates for the spectrum work. Mr. Lockyer proposes to obtain a special image with each portion of the spectrum by using an objective prism which would give monochromatic rings. Instan- taneous photographs are wanted to possibly set at rest for ever the problem of the " reversing layer." The Electric Iiig'ht in Practice. — The cost of producing the electricity is the one cause why its use for illuminating the sitter is not almost universal in large portrait studios ; but it is true that the continual progress of discovery has already resulted in cheapening electric lighting, and a communication to the Institution of Civil Engineers by Mr. J. Emerson Dowson on Gas Potver or Electric- Liyhtiny, is one of the most practical contributions to the study of its cost and practicability yet brought forward. We need not here quote his paper beyond giving the conclusions he arrives at, the following being a summary : — "1. When town gas was used for driving the engines of an electrical station, the con- sumption was about fifty per cent, less than the volume of gas required to give the same amount of light by ordinary burners. 2. When town gas was used neither boiler nor firemen were re- quired, and there were no ashes to be removed; less space was needed; no accumulators were required, except such as might be necessary to equalise the load of the engines, and to provide for a small amount of storage. The engines could be worked in the most crowded districts, close to where lights were required, and whert- boilers were not allowed. 3. When ' generator gas ' was used, the consumption of fuel under a full load would be at least fifty per cent, less than with steam power, and the loss due to steam boilers iijot being fully worked could be almost entirely avoided.'' LECTURES ON PHOTOGR.IVURE. In" connexion with tlie affiliation of Photographic Societies with the Photographic Society of Great Britain, we are happy to announce that two lectures, together with a practical demonstration of photo- gravure or photo-etching on copper, will be delivered by Mr. Herbert Denison (of Leeds), at Bloomsbury Hall, Hart-street, Bloomsbury, London, W.C., on Friday, February 17th, and Friday, February 24th,. at 8 p.m., when Mr. J. Traill Taylor will preside. The syllabus of the first lecture is as follows : — General introduction and the principles of the process ; appliances and materials required; the negative ; the reversed transparency and its preparation for the printingof the resist ; printing the resist ; and that of the second lecture : — Resume of first lecture ; preparation of the copper plate ; laying the ground ; fixing the ground ; transfer of the resist to the copper ; development of the resist ; drying off ; protecting the margin ; the etching : finishing and retouching the plate ; pulling a proof. A practical demonstration will be given of each step in the process after the verbal description. Admission to members of affiliated societies is by tickets, to be obtained beforehand from the Hon. Secretary of their Society, one shilling the two lectures. Non- members will be admitted, by tickets obtainable at the doors, or on application to Mr. R. Child Bayley, Assistant Secretary, P.S.G.B., oO, Great Russell-street, Bloomsbury, W.C., two shillings and sixpence for the two lectures. Bloomsbury Hall is within two minutes' walk of the British Museum, Mudie's Library, and the Bloomsbury Tramway Terminus. There are now, we believe, something like thirty societies affiliated to the parent Society, and during the past year a joint committee, of which the late Mr. William Bedford was one of the most active members, has been constantly at work in the endeavour to ascertain the best means of giving beneficial effect to the scheme. It will be remembered that members of the affiliated societies were conceded admission to the Society's Exhibition at reduced rates; that several "f the papers read at its meetings were placed at the disposal of IjoJies affiliated ; and that other minor advantages were either promised or bestowed. The lectures on photogravure about to he delivered are the further outcome of the desire of the affiliation committee to couf-.' r .lanuarv 27,1803] THE ERITISIl JOURNAL OF PHOTOGRAPH V. advantages of a practical uature upon members of societies that have supported the parent society by seeking afliliation to it. The opportunity of witnessing a practical and complete demonstra- tion of photogravure does not often occur, and tlie present one there- fore shoultl be seized by all those interested in the subject. We appeal to members of affiliated societies and to our readers generally to support by their presence the two to be given next month, which we hope will be so successful that they will be but the forerunners of many practical demonstrations on other subjects. 68 A SEASONABLE PRINTING PROCESS FOR AMATEURS.* In the matter of pigments the amateur can avail himself of the finely ground and carefully prepared artists' colours in tubes, but on a large scale, in such an establishment as the Autotype Company's, it is necessary to grind the colours on the premises, and this, togethei- with their thorough mixing in large quantities of gelatine, absolutely necessitates costly and extensive mechanical arrangements. Again, the coating of the continuous rolls of tissue can only be performed by means of elaborate machinery, whereas the amateur may in a single evening coat sufficient paper or tissue to last him for a very long while, and with no more complicated arrange- ments than a sheet of plate glass and a levelling stand. One word of caution may be offered to any of your readers who may embark in the preparation of tissue for carbon work, namely, that the samjiles of gelatine that are sold for eraiUsion purposes, and whicli answer best when so employed, are qttife unsuite'd for our pre- sent purpose. It cannot be too strongly borne in mind that the treat- ment such gelatines undergo during the process of manufacture in order to harden them, confers upon them the very opposite charac- teristics to those required for carbon work, where a perfectly soluble and yet sound gelatine is a sine qua non. Many of the artificially hardened gelatines become spontaneously insoluble in contact with bichromates, or may even be actually precipitated, and the employment of such can only lead to the most complete failure. Nelson's photo- graphic gelatines Nos. 1 and 2, and their No. 1 Flake, are suitable kinds, but the " X Opaque " of the same makers, together with most of the foreign brands specially made for emulsion work, are to be shunned. Beyond the careful and thorough diffusion of the finely divided pigment throughout the mass of gelatine, and the subsequent straining througVswan's-down or similar material to remove accidental particles as well as air-bubbles, there is no special care required in the preparation of the tissue. The paper employed may receive some little attention, as it is important that it be readily penetrable by wator, without partaking too much of the bibulous character. The various papers sold for photogi-aphic purposes will answer well, but are of unnecessarily good quality for the purpose. A stout and fairly good sample of printing paper will serve every purpose ; but highly surfaced and sized papers should be avoidcjd as not permitting the free access of the water to the under side of the film in development. In coating with the pigmented gelatine it is only necessary to thoroughly damp the paper and squeegee it on to a sheet of levelled plate glass, removing all superfluous moisture. A measured quantity of the coloured gelatine is then poured on and allowed to set, after which the sheet is tacked by two of its edges to light laths, after the style of a map, and hung up to dry, which it will then do without much cockling or distortion. It is absolutely impossible to give any definite proportion for mixing the coloured gelatine, as the pigments themselves vary so considerably, and actual trial is the only safe plan. The best course to adopt is to first mix a quantity of colour to the desired tint. ii>ing as the basis liquid Indian ink or China ink and any of the more permanent of the tube colours to produce the modification of tone. Then, having prepared a solution of gelatine of the strength of from eighty to one hundred grains to the ounce, add the colour gradually until the correct depth has been obtained. It will probably be necessary to prepare, sensitise, and develop one or two sample pieces of tissue before the exact depth is reached, but there is in this process as in others considerable latitude. I do not advise the preparation of sensitised tissue for the reason • Concluded from page 20. already given that it keeps too short a time. Besides this, in the absence perhaps, of very perfect drying arrangement*, if the operation should be, in consequence of the presence of excessive moisture in the atmo- sphere, a protracted one, the presence of the bichromate would very probably lead to partial or total insolub'dity of the tissue before it was ready for use. The unbichromated gelatine, however, runs no such risk, and the operation of drying it after sensitising is a far shorter one than the original dessication. That tissue making is not a particularly difficult process is proved by a series of prints that were shown to me a few days ago, the production of an amateur on home-made tissue. Compared with duplicates in silver the carbon prints were in every case superior, although the negatives were all of them fairly good ones for silver printing. W. B. Bolton. JOTTINGS. Thamk you, Mr. H. M. Whitefield, for your handsome acknowledg- ment that The British Joubxal op Photogb-vphy is a " source in which nearly all things photographic can be found." The high falutin', in which some recently established photographic journals are fond of indulging, and by which alone they exist, looks very funny to old students of photographic journalism, who must derive great amusement from the frequency with which, in those papers that are constantly telling their unsophisticated readers that they never publish intelligence after their contemporaries, item? of photographic news are reproduced weeks, months, and sometimes years after their original appearance in these pages. More than one of your con- temporaries not only conveys your matter, but also the style of it ; and, as for the genial journalist who a year ago accused you of copy- ing his "side headings," and more recently said that the Almax.vc imitated his annual in the matter of illustrations. I am sure he would not have said such things had he known what was done in photographic journalism long, long before he entered it. The Editor's warning as to the danger to health lurking in the careless use of mercuric chloride should be laid to heart by photo- graphers, who, however, I should like to point out, when employing it for intensification purposes, have no need to immerse a greater portion of the hands than the finger tips in it. This reduces all danger to the minimum. I have, nevertheless, watched photographers, when using a tolerably large volume of the solution, place their hands as freely in it as if it were merely plain water, and not attempt to dry them after- wards.} I do not know how surgeons treat their hands after they have had them in a mercury solution, but not long since I was present in the laboratory of a friend who was conducting some experiments necessitating the sterilisation of the substance he was working upon, and after the hands had been bathed in the mercurv they were care- fully dried and then rapidly passed through a gas flame to " sterilise " the hands and possibly to remove the last traces of mercury. There are undoubtedly some good points about the piece of apparatus for developing plates in a vertical position without the use of a dark room which Mr. Alexander Watt describes ; but the fact, that such a system is useless except for correctly exposed plates, at once places it out of court as regards practical utility, except, of course, to the experimentalist, who works on different lines and for different objects to the average professional or amateur photographer. Until we have all learned to expose our plates with absolute accuracy, such attempts to obviate the necessity of using a dark room must naturalh' be just so much wasted labour. As regards vertical development, however, 1 think that, if ever I desired to employ it, I should not search further for the necessary piece of apparatus than one of those grooved vertical porcelain baths to be had of the dealers. These, I believe, are made to hold three, six, or a dozen plates, and would answer just as well for developing as they do for fixing or washing. Reading all that has been written about amidol — ^r, at lecst, a considerable part of it, for to an old hand a new developer ou 54, THE BRITISH JOUENAL OF PHOTOGRAPHY. [January 27, 1893 paper will only go down in homoeopathic doses— one conclusion is irresistibly forced upon me, and that is, that, after all, pyro has out- lived the rivalry of hydroquinone, eikonogen, and para-amidophenol, and Jtakes rank aa the standard developer by which newer sub- stances must be judged. I have submitted amidol both with and without alkali to a series of trials, but save and except that it is extremely energetic in cases of under-exposure, cleaner in working, and conserves its power for a longer time than other compounds, I can discover no advantage in it over pyro and ammonia sufficient to justify the abandonment of an old friend where it gives satis- faction. At any rate, for negative work I can get all that I require with the latter, and so long as that is the case I shall not relinquish its use. For bromide work, however, amidol is, I think, superior to iron, as I find it does not clog the shadows, gives a nicer colour, and requires no subsequent acid bath. I have often wondered whether any practical advantage could be taken of the phenomenon of shearing stress — that is, the fact that the application of a developer to a plate of gelatino-bromide of silver which had received mechanical pressure produced reduction to the metalhc state, and more recently, on the publication of Mr. Carey Lea's experiment proving that great mechanical pressure alone suffices to darken the silver salt, the same thought occurred to me. There seems to me to be some feasibility of utilising the idea for reproduc- tion purposes, and I commend it to the attention of experimentalists. I should like to know why (1) Mr. Henry Crouch believes that ordinary cameras are being gradually superseded by the hand camera, and that sooner or later the former will be a thing of the past. (2) Mr. A, R. Dresser believes that stopping down the lens does not increase the definition for enlarging purposes, although it may appear to do so. (3) Mons. Sauvy has resumed business at Manchester, and advertises the fact, when " Mrs. Hargreaves " also advertises that she has bought the business. (4) Retouching by electricity is regarded by some men as practicable, (o) Whether, judging by the financial success of the " free portrait " scheme, there are not more fools than Carlyle imagined in the population. (6) Why Mr. Horsley Hinton does not like his friends to say that he believes in " nothing but photographs put confusedly out of focus, printed on exceedingly rough papers, and in a reddish brown colour, fallaciously called sepia ;" and (7) why (by the kindness of the Editor) I have received several letters containing all sorts of painful threats against Cosmos. FURTHER NOTES ON METOL AND AMIDOL. Journal of the Photographic Society of India.) I HAVE not been able to work much more with metol and amidol, but the following few notes in continuation of those in last month's Journal may be of interest. Mktol. Metol, I find, seems to work best with potash carbonate, but it has a decided tendency to give veiled images, and may require a little l/omide to give the best results. The stock metol solution with sodium sulphite keeps well, and it is altogether a clean developer. The electrolysis of metol solution presented some peculiarities, and made up as a developer with carbonate of lithia it has shown itself more active in evolving hydrogen than any other developing agent yet tried except ferrous oxalate. I have not yet been able to try a metol-potash solution in the voltameter. A solution of metol at 1 to 200 of distilled water was electrolysed in a tube voltameter with platinum electrodes, using 4 gravity cells giving a fairly constant current of half an ampere under a pressure of 44 volts The current through the voltameter at starting was about 10 milliamperes, with a pressure of 28 volts ; but after about 10 minutes it sank to 6'.5 milliamperes, with a pressure of 2-3 volts, and remained steady at that for the next 20 minutes. The yield of hydrogen was about '3 c.c. in o minutes ; 'o c.c. in 10 minutes ; '1 c.c. in 20 minutes; and about I'o c.c. in 30 minutes. A purplish sub- stance formed round the anode, colouring the solution in the oxygen tube and working out into the body of the solution, which at the end of the experiment was of a purplish brown inky colour. With silver electrodes the result was very different. The current through the voltameter at starting was about 8'o milliamperes, with a pressure of 25 volts, and in about 30 minutes it had slightly increased to 8'75 milliamperes with a pressure of 2'o5 volts. The yield of hydrogen was greater than with platinum electrodes, being about 3 c.c. in 5 minutes ; '7 c.c. in 10 minutes ; 1'3 c.c. in 20 minutes ; I'D c.c. in SO minutes. In this case the solution round the anode and in the oxygen tube remained quite clear, while the purple sub- stance was formed about the base of the cathode, discolouring it and the solution in the hydrogen tube. The anode was covered with a pulverulent deposit of silver, and very finely precipitated silver was also diffused in the solution. In both cases the hydrogen formed a brownish froth at the top of the hydrogen tube, and it was difficult to estimate the amount of gas liberated. A second experiment with a battery of three dry cells gave a similar result. A solution of metol and lithia carbonate — Metol 1 Lithia carbonate 2 Sodium sulphite. , 10 Water 200 was electrolysed with platinum electrodes, and a current from 4 gravity cells. The current through the voltameter at starting was 3.J milliamperes with a pressure of 32o volts, and remained fairly steady. In 5 minutes 1'8 c.c. of hydrogen were given off, and in 15 minutes 6 c.c, which is a very much larger proportion than usual. Some gas was also given off from the anode, but not in measurable quantity. The hydrogen was frothy as before. After lo minutes the solution was only slightly yellow. The anode was surrounded by a deep yellow solution, and the solution in the oxygen tube was yellow. In the hydrogen tube it was quite colourless. Amidol. A plain solution of amidol at 1 to 200 of distilled water was electrolysed with platinum electrodes and a current from 4 gi'avity cells. At starting the current through the voltameter was 10 milli- amperes with a pressure of 2'1 volts, which decreased to 9 milli- amperes and 1'75 volt in 30 minutes. The yield of hydrogen was •5 c.c. in 6 minutes; 1 c.c. in 10 minutes; 1"8 c.c. in 20 minutes; and 23 c.c. in 30 minutes ; about '5 c.c. of gas was also evolved from the anode. The anode was stained brown, and the solution turned a deep claret colour. No decolourising action was noticed in the hydrogen tube. With silver electrodes and the same battery and general arrange- ments, the current at starting was 23 milliamperes with a pressure of 3'1 volts, and at the end of 30 minutes it was 19 milliamperes with a pressure of 3 volts. Hydrogen was given off more freely than with the platinum electrodes, the yield being in o minutes '6 c.c. ; in 10 minutes, 1"3 c.c. ; in 20 minutes, 24 c.c. ; and, in 30 minutes, 3'5 c.c. No gas was set free from the anode. The anode was covered with a compact deposit of dark purple on the outside and greyish inside, which separated afterwards in flakes, probably an oxyehloride. The cathode was quite clean. The solution was very dark but clear, and no decolourising action was noticed in the hydrogen tube. It may be noted that, if a solution of amidol be added to a solution of silver nitrate, a thick white deposit as of chloride of silver is at first thrown down, but the solution speedily takes a rich crimson colour, and the precipitate is redissolved, silver being reduced. The voltameter used on the above experiments consits of a glass vessel holding about 4 ounces of solution, closed at one end with a cork ."bout Ij inch in diameter. The electrodes are of platinum or silver about f inch wide, 1 inch long, and about 1 inch apart, the wires from them passing out through the cork below. The- gases are collected in graduated measure glasses divided into tenths of a cubic centimetre. The galvanometer used is one of Edelmann's absolute unit galvano- meters reading up to 12 volts with 1000 ohms resistance, or to 12 milliamperes with 100 ohms resistance ; with 10 ohms resistance up to 120 milliamperes, and with 1 ohm resistance up to 1200 milh- amperes. It also has a separate shunt of O'l ohm resistance, by which stronger currents can be read up to 12 amperes, and an extra resistance of 9000 ohms, which enables pressures up to 120 volts to be measured. I find it a very useful and convenient instrument, and it is quite portable. Colonki, J. Waterhousb, I.S.C, Assistant Surveyor-General of India. rON THE PRODUCTION OF BLACK AND WHITE NEGA- TIVES BY MEANS OF ARTIFICIAL LIGHT. I. At some time or other it generally falls to the lot of most workers, be they amateur or professional, to copy a subject in black and white, such as a manuscript, engraving, a page of printsd matter from a. January 27, 1896] THE BMTISH JOURNAL OF PHOTOGRAPHY. K book, or some other similar subject. With expert workers, such ao those liaving- experience in the production of negatives for photo- meclianical work, this is at all times an eany matter of accomplish- ment, for, as a rule, they beinj? conversant with the working of collodion (a process especially suitable for this class of photography), the work offers no difficulty ; but among the great army of non-expert workers, even including' professionals, collodion work has been dis- carded long ago, the aroma of which is now but seldom felt even in studios. It is the dry plate, the dry iJate on all hands, for all pur- poses, no matter how fittle such be suited for many of the commis- sions a professional may have to execute. Many have been the attempts, therefore, on the part even of experienced workers, to utilise gelatino-bromide for black and white work, as against the undoubted claims of collodion when properly understood. Nor have plate-makers been slow to recognise the importance of catering specially for this class of work, the outcome of which has been that at least one finn has for a considerable time placed on the market a very excellent plate for photo-mechanical purposes. There is, how- ever, a very wide range of work outside that of photo-mechanical in which it is desirable that black-and-white negatives of special features be produced, such as the copying of black-and-white subjects for the purpose of producing lantern slides for lecture sets or the reproduc- tion of such subjects by printing on bromide or platinotype, the latter in either paper or textUe fabric, whereby an amateur may experience much pleasure in prosecuting such work by means of a gelatino- bromide dry plate, provided certain well-defined lines are followed in their manipulation. In making these remarks, I do not wish any one to imagine that I in any way advocate the use of gelatino-bromide for this branch of photography in preference to collodion. 1 am a true lover of ray silver bath, and with me such is always kept in a working condition (and a very handy thing it is to fall back upon on many an occasion) ; but there is no use Winking the fact that not one amateur in 500 knows an3-thing about collodion work, and until such time as we have schools of photography, or the heads of our large amateur associations arrange for regular courses of instruction in this and many other almost forgotten branches of our science, it is not likely they will know much about it ; for I fear professionals are fast " keeping much up their sleeves," as the saying goes. To such workers, therefore, as are desirous of producing black and white negatives by means of gelatino-bromide, I offer the following suggestions, and they are the result of much close study on my part, and, I believe, point out, as good if not the best, lines to follow when it is desired to copy black and white subjects by means of gelatino- bromide. Undoubtedly some of the first considerations, when undertaking this workare : What arethebestsourceof illumination to employ; and, what is the best method of using such in lighting the subject it is desired to photograph ? A worker having no practical experience may very likely imagine that, to obtain the best results, it is necessary to employ day- light for the exposure of the plate ; but, although daylight is in many ways preferable to artificial light when following most branches of photo- graphy, experience has shown me that quite as good results are to be obtained by a well-arranged system of artificial lighting as is possible with daylight. I desire, however, to qualify such assertion to thisextent — that there is undoubtedly a limit to which artificial Ughting is applic- able. In eases where such work as the copying of large maps, plans, and framed engravings of very large size are concerned; there is no doubt that better or more even illumination is obtained by means of day- light than is at all possible by artificial light, but it seldom happens that amateurs or non-experts have such extreme sizes to deal with. The more commonly met with sizes will run from about four inches up to fifteen, and such are perfectly capable of being dealt with by a system of artificial lighting. Having said so much may be accom- plished by means of artificial light, a student would do well to give some thought to a few very important factors in the matter of what is the proper amount of liglit to employ, or in other words, to under- stand thoroughly the difference between the intensity and quantity of light he is to use. I sometimes think that there is not sufficient notice taken by workers of the difference which exists between these two important factors when practising photography in many of its branches. Somewhat recently I happened to remark to a gentleman that as regards the quality of the resulting picture it mattered a good deal whether t lie exposure was made with the aid of a bright light and a small stopj or a weaker light and a larger stop, the exposures being calculated corr ectly for the different stops. My friend could not see that there would be any difference, say, in the case of taking two negatives of a landscape, aliko in every other respect as regards colour, &c., but different in light. Suppose the first negative was made at a moment : 4 to reach us on the morning of a given day, and on the following morning fifty or 100 copies reduced to programme size are in his liands for attaching to the dance list. Though such orders are executed in so short a time, it is obviously better to allow forty-eight rather than twenty-four hours in case of postal delays. — We arc, yours, &o., J. Mabtin it Co. 4 and 3 Park-villas, Neic Southgate, London, N„ January 23, 1893. AMIDOL FOR LANTERN SLIDES. To the Editob. Sin, — My attention has just been called to a letter in your issue of the 23rd of December, 1802, by the Rev. E. Healy, in reference to the use of amidol for lantern transparencies. I must apologise to the writer for having overlooked his query. If he will refer to my paper in the Almanac, he will see that my remarks are suggestive and tentative, and give those results which in practice I have found the best. Mr. Healy can easily vary the proportions and find if his experiments prove me to be somewhat in error. — lam, yours, c in , the Pliotographic l.'hili held its Annual Ladies' Night and Entertainment, when, in addition to the disjilay of a large number of excellent slides by members, some capital vocal and instru- mental music was discoursed by Miss Minnie Kirton, Mr. A. F/ Kipps (piano), Mr. F. A. Bridge, and Mr. M. C. Gaze. A large company assembled in response to the Club's invitation, and a thoroughly enjoyable .and successful evening resulted. Photographers' Benevolent Association. — A meeting of tlie Committee was field in the rooms of the Photographic Society of Great Britain on Friday last, Mr. Mackie in the chair. Before opening the business of tlie meeting the Chairm.an feelingly referred to the death of Mr. William Bedford, the Chair- man of the Committee, which had occniTed tliat morning. An application from a pliotograiiher who had previously been assisted by the C'omniittee, but who had only been able to secure odd jobs during the winter, and who was again in difficulties, was considered. The sum of 2/. 10«. was granted, and the Secretary was also instructed to pay the applicant's rent for several weeks if that should be necessary, A second application was from a iihotograjiher who had been in business thirty years, but now incapacitated by blindness. Ap- plication for a grant to assist in refurnishing part of his house, so that his family might eke out a subsistance by letting furnislied apartments. Tlie sum .asked for was granted, subject to the statements being verified and references satisfactory. "The case of an applicant to whom a loan had been granted some time ago, and repayment of which was overdue, was discussed. From investi- g.atioiis made, it seems as if the defaulter was attempting to evade repayment. The Secretary was instructed to pursue the inquiries further, and, if it appeared that the defaulter was now able to jiay, to take immediate legal proceedings for recovery. The report and b.alaiice-slieet were discussed, and the Secretary was instructed to call the annual meeting for February 3. OONTSNTS, PAa« BEPBODCCIXO negatives FROM PAPER PRINTS' 49 CHHOMATE of SILVKR SO PHOTO-PLASTIGRAPHY M LECTUHISS ON PHOTOGRAVURE 62 A SEASONAIlLE PRINTING PROCESS FOR AMATEURS. Ev W. B. BOLTON 5S .IOTTINGS, Dv COSMOS 53 FURTHER NOTES ON METOL AND AMIliOL. Uv COLONEL J. WATEK- HcirsE, ISC 54 ON THE PKOIlUCTION OF BLACK AND WHME NEGATIVES BY MEANS OP ARTlFICIAl, LIGHT.— 1. By T. N. AliMSTRONG .i4 .JAItrini,, II,- A. R. DRESSEK .■.^ i;i;o:;:;n i;:i;iEs. Bj- w. i:, iM.v;rs.. ;.; Faob determination of plate speeds. —I. Bv G. F. WILLIAMS 5« THK hand camera and its USE IN PICTURE-MAKING. By W. THOMAS.. .17 LIQUID AIR 611 COMPOSITH HELIOCHROMY 59 RYE AND WINCHELSEA WITH THE CAMERA CO PHOTOGRAPHIC SOCIETY OF IRE- LANDS EXHIBITION f.O THE EYE AND THE CAMERA (U "SPIRIT" PHOTOURAPHY 61 OUR EDITORIAL TABLE, (51 MEETINGS OF SOCIETIES 62 FORTHCOMING EXHIBITIONS fl-l ConUKSPONDENC-" 61 A.\S,\Xi;a TO CORRESPONDENTS 01 THE BKITISH JOURNAL OF PHOTOGRAPHY. No, 1709. Vol. XL.— FEBRUARY 3, 1893. STEREO-MICROGRAPHY. There are indications that, on the Continent the highly useful and attractive system of photographing microscopic objects as stereoscopic slides is likely to be once more brought to the front. The superior attractiveness of binocular over monocular microscopes is evinced by the immense numbers of these that are now made. We do not, however, purpose here to institute any comparison between these two methods of microscopic examination, but shall at once assume the desirableness of seeing on an enlarged scale and by photographic agency these minute objects in all the solidity of nature. Impfimis, a micro-stereograph does not by any means imply that a binocular microscope must be employed in its production, for some of the most effective of these pictures we have seen have been obtained by the usual instrument having a single barrel — nay, for most purposes it is to be preferred. Again, there are many organisms so exceedingly minute as to render it difficult to conceive of them as capable of being photographed under circumstances conducive to showing stereoscopic effect, any more than they would be amenable to direct visual binocular examination under a microscope bearing what may be termed an excessively high power. The conditions under which a microscopic stereograph must be made are identical with those of an ordinary binocular picture, such as a portrait or view from nature, and the methods applying are similar in both cases, size of appliances alone ex. cepted. The one, however, is an enlarging, and the other a reducing, method. Uoth pictures must, in either case, be taken from a slightly different point of view, with a single exception to which we shall presently allude. One method, and a very simple one it is, for making a micro- stereograph is to place a cap over the front lens of the microscopic objective, which we may assume to be one of an inch or less in focus, one half of this cap being cut away, so as to allow the light from the object to be transmitted by either one side of the objective or the other, according to whether the cap is rotated to one side or the other. This will give dis- similar views of an object, which must be photographed by two successive operations. According to the distance of the sensitive plate from the objeotive, so is th-^ magnification ; but on this merely elementary topic we neeil not dwell, it now being well recognised by al.'. The pair t f enlargements thus obtained, when printed and mounted sde by side on a card, present true stereoscopic relief when viewed in a stereoscope. The defining power of a microscopic objective differs altogether from its penetrative power. Take a well-mounted object possessing depth and transparence, such as the head of a crane- fly, with which, as a test-object for this special purpose, we have of late been conducting several experiments. With an inch power we see the frrmt of the eye, but fail to discover the hack. With a two-inch objective the performance is more satisfactory as regards this quality, while with a still lower power we see both front and back. By sufficiently stopping down the one- inch objective we reduce its angular aperture to such an extent as to enable us to see both front and back of the insect's eye, and this is the condition we require for a stereoscopic photo- graph of this object. Observe now the image shown in a common monocular microscope, and the following anomaly will be apparent. Having noted the relative positions of the front lines of the eye with those of the back, .shift the light a little from one side to the other without disturbing, even in the slightest degree, the microscope in any other respect, the relative positions of object and the lens remaining the same ; when, behold, the relative positions of the front and back of the eye are changed. Taking advantage of this, pictures having a true stereoscopic effect may be most easily obtained by the very simple expedient of a slight motion from side to side of the concave mirror by which the object is illuminated, this, of course, being done previous to the making of the second exposure. This method was well known to a few of the hahltues of the now long extinct Photographic Society of Scotland thirty years ago, but we much doubt that it has long been forgotten. The conditions for micro-stereography with a monocular microscope are also fulfilled by a system we described in 1877, and which, together with other methods, we brought before the British Association of that year. It consists in having fitted to its main stage a super stage capable of being influenced by the mechanical adjustments of the instrument and also of oscillating from right to left within a limited sphere, for which purpose the slide-holder is pivoted in such a manner that tbe axis of motion nearly coincides with the object to be photographed. A picture having been obtained of the object when in one position, the oscillating stage is tilted in the opposite direction, and a second photograph obtained. These two form a pair which, when combined in the stereoscope, show the object in all its natural solidity. It will readily approve itself to the reader that, with regard to this latter method, the oscillating motion must be slight and the microscopic objective of very small angular aperture ; else, if the object be large, its sides will be lacking in sharpness. In another article we shall treat of methods of making stereo- micrographs by binocular projection. 60 THE BRITISH JOURNAL OF PHOTOGRAPHY. [FebrnarvailSgS RETOUCHING AND VARNISHES. A CORRESPONDENT, whose letter we publish in another column, puts a query which, no doubt, has often required an answer during tbe practice of other workers. He wishes to know how to prevent the retouching from moving when the retouched negative is varnished. The question is by no means so simple a one as at first would appear, and the reply will necessarily not be devoid of complications. First, let us take the mode adopted by the best workers in actual practice, which we believe we are safe in saying is to work upon the gelatine film itself before varnishing. Where the amount of pencilling is slight, the fine grain of the unpre- pared negative usually gives sufficient tooth to enable the pencil to bite without extraneous aid. Whei-e the e.xtent of retouching needed is beyond slight tints, it becomes requisite to prepare the surface. Some workers use a solution of gum arable, or other similar substance, for the purpose, but by far the larger proportion use one or other of the various "mediums" that are advertised for sale, or they make their own — a tere- binthinous solution of some resin being the standard formuln. There are hundreds of formula; to be found in photographers' note-books, no doubt each believed to be better than any other owing to its possessor being familiar with its working. There are also many different makes issued by dealers, and, of course, it is no part of our work to recommend one or other of them, or decide upon the merits of rival makers. We will simply present our readers with a recipe given to us in 1874 by one of the best and one of the earliest retouchers in this country. We have given copies of it to many workers, who have ex- pressed their satisfaction with it, the prevailing opinion being that the resin should be in larger proportion ; that, however, is a mere detail, which each can manage to settle for himself. The recipe is as follows : — Gum dammar 30 grains. Venetian turpentine C „ Rectified turpentine 4 ounces. Dissolve a little to be rubbed on the negative, and tlie surplus wiped off with a pledget of cottoa wool after a few seconds. At the date that the above was communicated to us, the gelatine plate was a thing of the future ; hence it will be seen that the medium was intended to be used upon the varnish. We may say, however, that (when made stronger) it has been in frequent use for worki^ig direct upon the gelatine. We will assume that anegative has been fully worked upon after the manner intimated, and that it is necessary then to varnish it. En passant, we may repeat advice often given by us, namely, that every negative from which more than one or two prints are needed should be varnished, otherwisesilver stains are so very liable to make their appearance. If the above medium be used, the experimenter need have no fear whatever of the retouching shifting or becoming blurred when varnished with ordinary alcoholic varnishes and by heat. If, however, a needlessly thick and sticky medium be used, there will be danger of its being dissolved and the retouching floated out of its place. To this extent our correspondent's (piery is replied to. But, when tlie retouching is performed upon a varnished negative, troubles set in and multiply fast. Many will say, " What is the need of varui.-ihing ?" and it may he at once said that its advantage is only a])[>arent when a large number of prints are needed, or when the negative has to be stored away for future use when required. Under other conditions we would say decidedly, " Leave varnishing alone." The drawback in printing from a retouched negative not protected by a second coating of varnish, is that the combined friction from the paper placed in the frame to print and the necessary brusliing or dusting to keep the surface clean, abrades and gradually removes a portion of the work, tdl at last its delicacy is quite lost. Wheu the question of varnishing is to be faced, difficulties arise quickly. Many use liquids, with benzol as the solvent, and with a suitable resin the plan is good. But some photo- o-raphers strongly object to the use of benzole in anj' form, from an objection, first to its smell, and secondly, to the danger of fire its presence gives rise to. As for ourselves, we have tried methods of protecting the retouching in such a way as to render possible the giving a second coat of alcoholic shellac varnish, so as to involve the smallest amount of trouble in routine work. We have tried collodion, solutions of gelatine, spraying with sundry liquids devised to protect the first varnish from being sottened and dissolved, and so causing the pencillmg to shift or run. We are not in a position to say that any of the methods tried have been invariably successful ; for, just when we have come to the conclusion that our plans had succeeded, a number of plates having been varnished and the work left intact, we have found a fresh plate, apparently identically treated, quite spoiled, through the softening of the varnish and the runumg together of the pencilling. Hence, although, beyond the objectionable benzole varnishes, we have had suc- cesses, they have not been so uniform as to warrant our recoui- nieniling a particular process to our readers. Wu have still further experiments in view, the results of which we hope to communicate at some future period. Meanwhile, no doubt, our readers would be pleased to have the experience of workers who find themselves able to re varnish a retouched noga-ive with ease and satisfaction. The 18S)3 Convention. — The date of the ISO-'! Convention, which is to be held this year at Plymouth, has been fixed for the week commencing J ulv 3 ne.xt. An Invitation. — The Hon. Secretary of the St. Louis Camera Club writes : — " If any of our English cou.-iiis should happen this way on their visit to the World's Fair at Chicago duiing the coming vear, we trust that they will remember that our ' latch string always haugs ou the outside,' aud they can rest assured that we V ill do our beat to make their stay in St. Louis a pleasant oue." Painters versus Engravers. — Photographic engravers frf- quently jret into disagreement with artists in the reproduction of their works. Usually the work has to be done to the satisfaction of the painter, aud he is often a " faddist," and luxs strange ideas as to how his different colours should be rendered in monochrome. Often ii mis- conception of terms as used by the painter and the engraver exists, and this sometimes leads to unnecessary alterations, to the serious deteriora- tion of the work, in order to conform to tlie painter's ideas. Provisional Specifications. — Over 24,000 provisional .speciticiitions for patents were accepted lust year, but possibly not une tithe ot' this uumber will be furtlier proceeded with. A pro- visional specification onjy costs a pound, and many are lodged with no idea ot the patent ever being, completed, but merely to use the term for adverii-ing purposes. This remark applies to photography us well as other things. When a provisional specification is lodged, which may be done for anything-, no inquiry or investigation is made as to the originality or the practicability uf tlie .lUeged invention for which protection is claimed. As a proof of this, it came out in evi- dence in the case of Wells, who stands charged wiih fraud, that. February .3, 1893] tHE BRITISH JOUKNAL OF PHOTOGRAPHY. 67 during the last few years he has filed no less than 102 specifications, lliough lie only completed one patent. A patent can be obtained for almost anything in this country, unless it be opposed on the sealinff. Such is not the case in most other countries. Another Fatal Aooident from Ether.— In September last, we referred to an accident tlint happened in Paris at the house ■of a photoirraph enameller, through the breaking of a bottle containing ■collodion, by which several persons lost their lives. The vapour from the ether, mixed witli tlie atmosphere, reached a light, and then exploded. A very similar accident has occurred in London, though, fortunately, here only one life was lost, but there were some narrow escapes. The facts, as stated at the intjuest last week, are these. One evening the enameller and his wife heard a hissing noise in a cupboard where a bottle of ether was kept. This was found to be the vapour from it ■escaping, and presently, so it was stated, the bottle exploded. A lamp on the table was at once extinguished, and the wife commenced to wipe up the spilt ether, when iU vapour must have become ignited by the fire in the grat-j, and thus set tire to the unfortunate woman's clothing. In all oases where ether is spilt, as we pointed out when referring to the fir:iviinvv3. 1>^9.'1 Wo. E.xperiment. 38. PI. X, speed 1401 ..22.G,60secs. „ X, ,, BU J 34. PI. X, speed 140 l^_22.gg0gg^g_ „ X, „ OaJ-' Eesnlt. The pair of negatives differ by 10 per cent. only. Theoretically the difference ought to have been 75 per cent, in favour of the higher speed plate. Practically the error in speed determination in thia case is no less that 65 per cent. The pair differ by under 10 per cent. Seeing that the difference should have been nearly 50 per cent., it proves that here again there is an error of 40 per cent. 34». Eepeated. Exactly confirms above. I miij'ht go on enumerating several other examples of these enor- mous discrepancies, but am sure it will suffice it I instance errors of from ten per cent, to sixty-fi\e per cent, to convince my readers that there is .something alarmingly wrong in this new-fangled method of determining the speed of plates. I refer for one moment to the experiments, and I point out No.s. 18, 21',, :'>2, 33, and :U. These, it will be noticed, are comparisons of speed of one make of plate, which I have called x. What do these experiments show? That 37 is under-estimated by about twenty per cent. ; that 80 and 100 only differ by ten per cent, in speed ; and that between 9.") and 140 there is really only about ten per cent, in favour of the 140, while 100, 135, and 140 are for all practical purpo-ses alike in speed. During my treatment of the plates in this series of experiments, of which the foregoing are a few selections, I hive been much struck by the great influence the thickness of the coating has upon the final re.=ult. For aught one could tell, some of the plates miglit have been coated from the same batch of emulsion (although bearing different speed numbers), the real or apparent difference cinsisting of a thicker or thinner coating. Again, some of the plate* started under the developer sooner than others, without, however, causing any dis- tinguishable difference in result at the finish. .Vny one who has had much experience in emulsion-making will bear me out wheni say that a difference of one or two per cent, of gelatine iu two similar emulsions will account for this. I have no space at my disposal to discuss here the rights or the wrongs of the method known as that of Hurter &; Driffield for determining the speed of plates. At the moment it does not concern the purport of these remarks ; all I intended to show is the utter unreliability of the system, and to prove that such speed numbers are fallacious and deceptive. I have shown tliat the half-dozen speed numbers of a given maker resolve themselies into two, or at most three, rapidities. For any other or roughe;- purpose than that of determining the speed of plates, possibly the method might be found suitable ; for instance, it might tell us what were the proportions of particles of carbon in a carbou print, but it will not do for plates. Probably I shall give my reasons for this anon. G. F. Williams. ♦ A CHEMICAL STUDY OF JklERCURIAL INTENSIFICATION. 1 Photographic Society of Great Britain.] In January, 1890, 1 read a pa])er before this Society On Control in the Density of Negatives {Photographic Journal, New Series, xiv. 40), and therein described the action of mercuric chloride upon a silver image and of ferrous oxalate upon the bleached image. Trie effect of sodiiini sulphite, instead of ferrous oxalate, was also shown, so far a.s the cliaracter of the resulting image is concerned. Since that time I have further studied the changes taking place during mercurial in- tensification, and I beg to lay before the Society those of my results that are of practical interest to photographers. I have obtained further evidence that the action of mercuric chloride upon metallic silver gives a double salt, and not a mere mixture of silver and mercurous chlorides, which, with other matters of a purely chemical interest, will probably be published elsewhere. The action of mercuric chloride upon the silver image is perfectly definite, but in practice it is found difficult, if not impossible, to pre- vent the mercury salt from combining with the gelatine when it is employed in a plain solution, and to prevent this it is usual to add a little hydrochloric acist entirely with the mercury, and the effect is practically a loss of mercury. This change, however, cannot take place in the presence of excess of mercuric chloride ; therefore the acid generally added to the mercury solution employed for intensification is harmless to the image. It has been suggested to add ammonium chloride to the mercury solution, presumably for facilitating the solution of the mercuric chloride. This addition is not to be recommended, because mercuric chloride is quite soluble enough in water alone, and ammonium chloride, if it sliould have opportunity to act upon the bleached image in the absence of mercuric chloride, would lead to a loss of mercury. Its final effect, when hot, is to dissolve out two-thirds of botli the silver and the mercury, leaving the rest in the metallic state. There is not tlie same safeguard in the u.se of ammonium chloride that there is in the case of hydrochloric acid, because large quantities may be present without injury to the film, and, as it is unnecessary, it is better to avoid the possibility of irregularity that results from its use. 1 have investigated the action of several reagents up(m silver mercurous chloride to elucidate the changes that take place when the image, after bleaching it with mercuric chloride, is blackened by the various methods that have been proposed. Action of Sodium Sulphite. In the previous piper the action of sodium sulphite was expressed thus :— 4AgHgCL=3HgCI., + L'AgCl + AgJIg. Dissolved by the sodium sulphite. ■ ' To this I can now add the statement that the mercuric chloride dis- solved forms merquric sodium sulphite, thus : — HgCl., + 2Na,S03=Hg(NaSO,,).,+ 2NaCl. The silver chloride is doubtless changed into sulphite, which is dis- solved by combination with sodium sulphite, but the proportion of the sodium salt required is not so certain as in the case of mercury. One molecule of silver chloride appears to require, as a minimum, about four molecules of sodium sulphite to dis.solve it, but practically more must be used to avoid secondary changes. The action of sodium sulphite may therefore be written : — 4AgHgCI., + 7Na„SO, + ,iNa..S03 = 2 Ag + Hg + 3Hg(NaS03). + Ag.,SO.„ .rlSi a.,SO, + 8NaCl., where x is equal to seven or more. The large quantity of alkaline sulphite necessary to dissolve the silver chloride doubtless leads to the leaving of silver chloride or sulphite in the image when an in- sufficiency of sodium sulphite is employed. This may account for the thinning action of hypo upon an image intensified with mercury and sulphite which has been observed, though I have never myself noticed this effect. As stated in my previous paper, if the sodium sulphite solution, with the salts that it has dissolved, is allowed to remain in contact with the metals left as residue, the mercury in the residue will dissolve, and metallic silver will take its place ; but, if intensificiition is carried out in the ordinary manner, this action is not likely to take place. It may be remarked in passing how greatly inferior sodium sulphite is to sodium hyposulphite as a solvent of silver chloride. The figures given above indicate that, taking the two crystallised salts, the former is only about one-third as efficacious as the latter, weight for weight. But this proportion must not be relied upon too implicitly for prac- tical purposes, because a considerable excess of the sodium salt must be taken in both cases to avoid secondary changes, and it is probable that a larger excess is needed in the case of the sulphite. Nor does this comparison include any difference iu the rapidity of action of the two salts. It appears that sodium sulphite acts more slowly than the other, and that, for this reason also, a greater excess of it would be desirable if it were to be used for practical purposes as a fixing agent. In the continuation of the investigation of the action of sodium sulphite, I have been ably assisted by my colleague, Mr. W. Kirman to whom I offer my best thanks. AciiON oE Sodium Hyposuluhite. Sodium hyposulphite rapidly blackens silver mercurous chloride, and, if an excess of it is used from the first, the change is of a simple, cha a;ter, and may be expressed thus : — 3AgHgCL=Hg + Ag + L>AgCl + 2HgC)„. That is, one-third of each of the matals is left in the metallic state, the two-thirds being dissolved. The silver chloride is, of course, changed into the double hyposulphite, as is well known, but there is no sufficiently definite information about the hyposulphites of mercury February.*!, J 89a] THK BUITlSn JOOUXAL OF PHOTOGRAPHY. 71 to pnabln one to state in ■whnt form it is flissolred. If the sodium Lypi>~iil[iliite is not in excess from tlii" tirat, tlu'ii Kulpliides of tli« niftals urc produced, und also sulphuric iicid, which ciiu.«e< tliw pre- cipitatiiiii of sulphur from the solution. My prolonginjf th» action of the hypo.sul])hite, the metallic mercury dissolves precipitating silver from tlm solution. AcTiox OF Potassium Cyanide. Potns^iuTn cyanide in solution lilacVens .silver mercurou? chloride with frreat readiness, and yives, like sodiuin hyposulphite, one-third of each of the metals in the re.-idue. Its action may be written thus : — .-JAg+IgCL + 8KCy =IIg + Ag + 2KAgCy„ + 2HgCyj + 6KC1. But the action of tlifl resulting solution upon the residue is different from that observed in the previous cases, for the metallic silver dis- solves precipitating mercury. Potassium cyanide is of no use as a follower to mercuric chloride in intensification, on account of the rapidity with which it attacks both silver and mercury wlien they are so finely divided as they are in gelatine film.s. It is probable that it was to avoid this solvent action that potassium cyanide was first s.aturated with silver cyanide, and this addition certainly does prevent the loss of image, but it also pro- foundly alters the reaction that takes place. Action of Potassium Silvkh Cyanidk. Potassium silver cyanide is produced by adding silver cyanide (or silver nitrate) to a solution of potassium cyanide until there remains an excess of silver cyanide which the solution is unable to take up. The use of such a solution, after mercuric chloride for bromide) has often been commended, since H. J. Burton described the process in the Year liooh for 187.i (p. fl7), and it gives a vip-orous intensification of a pood black colour with the minimum chance of staining, or like trouble. Mr. Burton very wisely and properly recommends this method for negatives of line subjects only, but others have since applied it to negatives of all sort*.' I have been bold enough, however, to con- demn such intensification of half-tone negatives, chiefly because the nrolonged application of the blackening solution thins the image. Some time ago I pointed out, and Messrs. Ilurter & Driffield have subsequently confirmed mv observation, that reduction of the image by such a process changes the character of its density gradation. But, even if there were no change of gradation, the reduction following the intensification leads to uncertainty, and the perfecting of technical photography demands the elimination of uncertainty. I am now in a position to condemn this method of inten.>ification more emphatically, Txjcause also of the composition of the resulting image, and because of ita want of uniformity. The primary action of potassium silver cyanide upon silver mercur- OU9 chloride may be expressed thus : — AgHgCl + KAgUy. = Ag -i- AgCl -i- HgCy + KCl. The residue contains, therefore, as metal, all the silver originally present, and to this has l>een added an equivalent quantity of silver in the form of chloride. This result is highly desirable, and, if only we could stop here, tlie method would be worthy of the highest appre- ciation, because it would only remain to reduce the silver chloride, and the image would be of pure metallic s-ilver in double the quantity first present. But there are secondary reactions whicii appear to be in- separable, or, at least, inseparable with any degree of certainty, from the primary change. The silver chloride, by reaction with more potassium silver cyanide, is replaced partially by a double equivalent of silver cyanide, thus : — AgCl -I- KAgCy.,=2 AgCy + KCl ; and the tilver chloride that remains holds to itself some of the mer- * Suice writing tliis paper, Mr. H. J. Burton has kimlly iiifomieil niu tliat the cyftuiile method of intensiti'-ation was told to liim tweuty-four years ago by ail operator workiii); at the British Museum, wlio learncil it from another operator. Mr. Burton adds tli.it " the metliod was worked in tliia way. A portion of the ordinar>' lixing bath of cyanide of potassium was put into a glass measure, aud a little of the intensifying solution addeil, and this was i>oiired over the negative alter treatment witli mercury liirhloride. Finding that, if tlie 1 cyanide of potassium was in excess, the action was irregular, I prepared it in the manner publishe*! l,y nie. i'or many years I have oeen in the haljit of adding to the solution, after the whole of the cyanide of potassium has coni- biueiece of hyposulphite of soda. This addition * ^ives tile ues.'jitivt. an intense Iila-'k colour instead «f an olive black." So far, therefore. a« I lia\e tieen able to get at the facts of the ense, it appears tliat the cyanide nnthoil of inteiisiticatiou ought to be cal'ed Burton's, and not Monck- lioveu K, if any name is to be attached to it. curie cyanide so tenaciously that prolonged washing only slowly removes a jiart, the remainder resisting, apparently, any amount of washing. The residue, therefore, consist? of the metallic silver originally present, with silver chloride, silver cyanide, and mercury cyanide. By prolonging the action of the pota-ssjum .silver cyanide, the silver chloride and the mercuric cyanide will decrease, the silver cranide will increase, and the metallic silver will tend to dissolve. By pro- longing the washing, the mercuric cyanide will decrease. Thus one cannot tell what may be finally present, and the composition of the images of different negatives intensified by this proce.ss cannot be expected to be identical. The image itself is not permanent ; it is affected by light. It is obvious that this method of intensification may be repeated on the same negative, but this is scarcely an advan- tage, because one application of the process is likely t > give too much density. Sodium hyposulphite thins the intensified imnge, leaving only the metallic silver, and it appears that it is po-sihle in this way to remoTe all that the intensification has added to the image. But it would not be well to rely too mucli upon this, because finely divided silver i« readily attacked by alkaline cyanides, and there might, therefore, be an accidental loss of metal. Action of Alkalies. Ammonia readily blackens silver mercurous chloride, and the general idea appears to be that the silver chloride is dissolved, and that mercurous ammonium chloride remains. This is not the case, for, though some silver is dissolved, the greater part remains in the residue. I have not yet completed my examination of this reaction, but ray results point to the probable production of two compounds in varying proportions, namely, NHoAgllgCl and XHAgHg,Cl. Almost the whole of the merniry remains in the residue. Caustic soda immediately Idackens silver mercurous chloride, re- placing chlorine by oxygen, liut the action is very diflicult, if not impossible, to complete. It i-^. without doubt, the .silver chloride that is so tardily affected. I'he residue consists of mercurous oxide, silver oxide, and silver chloride. If the alkali is allowed to absorb carbonic acid by exposure to the air, mercury will be dissolved. .Sodium carbonate acts more tardily than caustic soda, and dissolves a considerable quantity of mercurj'. PbaCTICAL CONCLirSIOKS. Whatever methods of intensification may suffice in occasional emergencv, I submit that we should have, for regular use, a method that worts in an exact and definite manner, that can be allowed to proceed to completeness without the possibility of any other change setting in to make the final result uncertain, one that does not produce too great an increase of density, and that leaves a permanent image of .simple and definite composition, which can, if necessity arises, be treated for further intensification, or other effects, with the same facility as the original image. This is the mori' important, because it is impossible to be sure of getting the density required by simple development when various subjects have to be photographed under various conditions. It is also impossible, without falsifying the gra- dation, to develop too dense, and afterwards reduce to the desired condition. By the use of mercuric chloride, followed by ferrous oxalate, the conditions stated are realised, and I do not know of any other intensifier of which this can be said. Since I drew attention to this matter three years ago, the method has been varied by one and another in the replacement of the ferrous oxalate by alkaline de- velopers. This change is not desirable, because of the uncertainty introduced as to whether or no the alkali has produced its charac- teristic change to a certain extent. Ammonia leave an image of a complex and variable composition, and sodium carbonate has a tendency to dissolve m -ury ; therefore, allowing that oxides as well as chlorides are reduc ' by the developer to the metallic state, the presence of any alkali im kes the change uncertain. I Iwlieve that any jiiotographer who takes the trouble to master the few difficulties that attend the use of mercuric chloride, followed by ferrous oxalate, will be very loth to use any other method for half- tone negatives. Tlie two chief precautions necessary are to eliminate the hypo that remains after washing before treating the negative with mercuric chloride, and to wash awav the excess of mercuric chloride before using the ferrous oxalate. The first is done by a few minutes' soaking in an acidified alum solution ; and by applying the ferrous oxalate in a dull light, such as is used for manipulating carbon tissue and printing-out papers in; if a little mercuric chloride is left when the ferrous oxalate is added, its only effect will be to retard the blackening of the image. CHArwAJt Joxrs, F.I.C., F.C.S. 72 THE BRITISH JOUHXAL OF PHOTOGRAPriY. [FMhriinrr .".. IPf).*? THE HAND CAMEBA AND ITS USE IN PICTUKE-MAKING.' The Causes of Failubes. It needs a good photographer to use a hand camera with any proper measure of success, but this is just what yon have a considerable number of among the members of this Brixton and Clapham Camera Club; and to such of you as may take up hand-camera work this year, and I trust to see some who will, and if used intelligently, I can promise you much pleasure, and, I am bound to say, some disappointments, but that will not be unexpected by those who have had any experience with the camera and tripod, as, even with this method— allowing time for consideration m all the stages up to actual exposure — yet failures are many with most of us, and when working the hand camera, it will soon dawn on any one taking it up for the first time, that the conditions are very diEferent— requiring a quick and decisive judgment as to what to take and what to leave, the proper moment to let the shutter fly, and, what often is of equal importance, a strong self-control, in order to hold back from letting it go just too soon. All this sounds formidable, and yet it is soon ac- quired by practice, and expenditure of a little thought over the pro8 and cons of the whole thing. I am afraid we amateurs give far t30 much time and attention to dash- ing up and down, making exposures ad lib., but very little time to sitting quietly and working out in our own minds not only what have been our successes, but, what is of infinitely more importance for future advance- ment, what are the canxe-t of our failures. Whether they be technical or pictorial failures, we might often spend a little more time over them with profit, and, it not understood at the moment, put them away, and afterwards something may turn up to explain the cause, and so enable one to guard against similar mistakes occurring. This question of failures is looked upon with different opinions by different people. The ruler of my household entertains strong opinions on the matter, and whenever I am just getting a choice collection gathered, she makes a rapid calculation of £ s. d. they represent, which calculation is generally of a generous nature, no stinting about it, and is a sure sign that at their next visit the dustmen are certain of finding a richer harvest of glass than usual (it may be some of you have a guardian angel ministering over you in a similar fashion). Find a Good Plate and Keep to it. lu leaving the question of plates, let me strongly advise all in doubt to tackle a good sound plate, and, having once found a suitable one, stick close to it. "It is better to deal with ii rogue ijou kninv tJioii one you don't know," so goes the old saying, and, striking out rogue and substituting plate, makes it a sound bit of photographic advice. So much for the question of pUte. It must be good, and rapid as possible if only one kind is used. It might be expected something ought to be said respect- ing colour-sensitive pates, but, beyond what is generally known of them and their special uses, we need not trouble to-night. They are useful, and of assistance when dealing with work having much yellow or red, as landscape in autumn, and may be of assistance in dealing with skies containing much blue, in contrast to light, fleecy clouds, and where any fog is about, but for ordinary work they are by no means an absolute necessity. Having disposed of the apparatus, how to use it is the next matter to claim attention. Any one commencing hand-camera work will, on be- coming possessed of one, naturally be eager to try it ; and, although it would be better to sit down and look the thing over for yourself, and arrive at a correct understanding of the purpose and working of its dif- ferent parts — infact.tborougdly make yourself master of its mechanism — yet no great harm will come from rushing off and trying it at once, beyond, perhaps, spoiling a few plates and indulging in the luxury of a few mild observations on some pe )plfc's stupidity, especially hand-camera makers, and then sitting down and going through the directions and looking over the camera, and finding the fault was all your own, and which materially adds to your 8ati^faction sometiwe<. Studyinq the Cambra — Some EEMISIsCJ:^c tf. This qneslion of studying the cumera and its working is a matter of far greater moment than at first would appear. The whole movements (it ii have an>) ma,-t be so understood and practised that they become a kind oi second nature, anj it is also necessary to work with system ; for instance, it is belter to change each plate immediately after the exposure, and then at once set the shutter ready for the next picture. By this means you avoid exposing twice on the same plate. After a little practice, it is done mechanically and as a matter of course, and there is no trouble on that score. I remember in my early working a hand * Conliaued from po^e 59. camera going off one afternoon to Greenwich and taking the boat to Blackfriars for the purpose of getting barges sailing. Well, it was a day in the week when even barges seem to go on strike, and the result was only one was met the whole way ; but it was a beauty, and, after getting everything ready while she was in the distance, I fixed myself in the bow of the steamer and waited. It is exciting work sometimes this waiting. You cannot tell which side you will pass her on, and the element ot uncertainty makes it enjoyable enough when things come right. On this occasion I had judged matters correctly ; the distance between us was rapidly narrowed ; one look at shutter and focussing lever, to see both were set right, and then the camera was held up, the picture composed on the finder a second, and the barge was near enough. And what a picture ! The sun shining brilliantly behind the top sail, throwing masses ot dark reflections in the water, relieved by touches of glittering light. The moment had arrived ! Shutter released, and much joy reigned in the breast of yours truly. The safety shutter inside camera was next to do its duty while setting shutter again, and on tenderly proceeding to carry out the necessary movement, I found it had faithfully been doing it all along. Never having been opened, and not having been coated with a sensitive film outside, but a good coat of black varnish, the picture had passed away, and its shadow also, instead of remaining on the trusty plate eagerly waiting behind that blackened door to receive it. I studied that camera in the evening in a desperate mood, hut to sohi'j 'pHr2ios^ — that mistake never has happened again. Work with System. Study the mechanical arrangements of your hand camera and work them with system, always doing the necessary movements immediately after each exposure, and rid yourself of one trouble — unccrtainti/ — and leave your mind free when called upon to arrange and take a picture. You will find, if aiming at the best results, you require every atom of undivided attention devoted at the moment to securing the picture desired, whether it be animals (human or otherwise), marine, or pure landscape. The knowledge of, and command over, your instrument is a matter of grave importance, and cannot be neglected without paying the penalty of frequent and needless failures. Hand-camera work is difficult enough, and to obtain good technical results is not the simplest thing in the world ; it behoves one to do everythin;,' possible to minimise the chances of failure. Well, we have got it all off by heart, and after putting some plates in, out we go into the park or lane, and, behold, some sheep are being driven along. A good Ught, suitable surroundings— everything promises well. We choose our standpoint, all being ready, shutter being set, &c., we wait until they are getting near enough, and then the ques- tion is. Where shall we hold the camera ? Whehe sbaIjL wk Hold the Cameka ? There are two things we must be certain of. First, holding it without movement during exposure ; and, secondly, so that we can see the finders plainly. Now, where is the position most likely to succeed in both these points ? After trying all methods, I prefer holding it to one's chest (like this) ; it enables you to see the finders perhaps better than in any other position ; you are able to get a firm hold ot the apparatus, and by holding your breath during the short time taken up with the exposure, run little or no risk of movement. There are other ways advocated — under one's arm by the side. This method, personally, I do not like, as I cannot get so clear and convenient a view of the finders. You may now understand my reason in advising that finders should be as large as possible ; it is a matter you will find have a serious effect on your results if not attended to. One last word. Great and unremitting care is needed in holding the camera steady, movement of a slight character being sufficient to spoil what otherwise might be a perfect production. It is almost entirely a question of practice and care. We will assume, please, you saw the composition on your finders satis- factorily, and made the exposure, and probably repeating the operation on other subjects. And, now we are b ick at home, and, naturally enough, desirous of seeing the wonderful results this new method ot working is to give us, so for the the dark room and the developer. What is this tj be ? The D..vi.loi'.:b. Personally I must confess at prese it to s.ick ng to the dirty but useful oil friends, pyro, ammonia, and bromide, and the use ot a little common sense. I should not presume to talk to you about development, many of of you having, no doubt, forgotten more than I ever knew upon the subject ; but this, and this alone, I may s ly respecting development of February 3, 189.5] THE BRITISH JOURNAL OF PHOTOGRAPHY. 73 hand-camera plates. Go for the detail, and keep back density — that can lUnays, and at any time, be obtained. Having got oat such detail as may be desirable, then go for density. I have tried within the last few days flashtng out the detail by using amidol stock solution dilated to six times it'* bulk with water, and one drachm of ten per cent, ammoniii added us accelerator — getting density by using stock solution full strength afterwards. This promised 80 well that 1 shall experiment further with it, trying other alkalies, and redeveloping with pyro and ammonia for density. Whatever developer is used, the method should be the same— detail first and then density, and thus produce negatives worthy of platinum or carbon printing. On this (luestion of printing, the thanks of all amateurs are due to Mr. Willis for placing in our hands such ar delightful process as his new cold-bath platinum paper, which is simplicity itself to use, both in printing and developing, and the results obtainable charming. I can strongly recommend any and all of you who may not have done 80 yet to try it. The notion entertained by many that negatives produced when working rapid exposures are only suitable for gelatinochloride emulsion, and that class of paper, is quite erroneous. Use a rapid plate, develop for detail and then density, get a good cold-bath platinum print, and you have something to look at with pleasure now and in after years if you are lacky enough to be able to keep it. [To he conclvdetl.) ♦ A VISIT TO MESSRS. MORGAN & KIDD'S COLLOTYPE WORKS AT RICHMOND. On January 30 a large number of members of the London and Provincial Photographic Association accepted the invitation of Mr. F. de P. Cembrano, the President of the Richmond Camera Club, to witness a practical demonstration, to the members of the latter Club, of collotype, under the superintendence of Mr. R. L. Kidd and his manager, Mr. Berghaff. After a very courteous welcome by Mr. and Mrs Kidd, and inspection of many fine examples of the work as exhibited in the showrooms, all adjourned to the large new building adjoining, the aspect of which (filled as it was with a magniticent plant and machinery, comprising all the latest improvements, and all the machines at work, under the guidance of a large staff of busy workers) went far to prove the assertions of some of the gentlemen present that Messrs. Morgan & Kidd, by their business enterprise, had placed themselves well abreast of any- thing of the kind in existence in this country. In introducing the subject to the gathering, Mr. Kidd gave the follow- ing description of the working of the process: — " An ordinary quarter-inch plate glass is ground on one side with the finest emery powder. It is then thoroughly cleaned, and well washed with water to get rid of the emery powder. When dried, it is coated with a substratum composed of solution of beer and silicate of soda : some prefer sugar and water instead of beer, but our experience is thai beer is preferable. The beer should be slightly warmed before mixing it with the silicate of soda. Without the substratum the printing composi tion would not adhere to the plate glass. " After the plate is carefully coated with the substratum it is then placed on a plate-rack, and allowed to dry spontaneously. When thoroughly dry, it is washed in clean water for a quarter of an honr, and then placed again to dry as before. " It is then put into the drying oven, perfectly levelled, and heated up to about 120' Fahr. It is then coated with a bichromated solution of gelatine and water, which must be of the same temperature, viz., 120 Fahr. This must be done with the greatest care to avoid dust particles, and secure a perfect and even costing. It is now left to dry for about two hours in u uniform temperature, which should not exceed 125° Fahr., care being taken to avoid draught or any unevenness of the drying, which would cause markings to appear in the printing of the plate. There are some workers who dry tbem in a temperature of 150 Fahr., but our experience is that this temperature is too high, and the results are inferior ; the higher the temperature the coarser the reticulation or grain will be, and this would interfere with the delicacy of detail. " We may point out that the printing from a coarse-grained plate is much easier than from a fine- grained plate, though the results are inferior. The coarse-grained plates are more used for commercial print- ing, as a much greater number of prints can bg pulled from the plate. The finer-grained plates are adapted fur high-class illustration*. " There are many formulii', and every co.lotyper has his own pet formula ; there are a great number published in the various photographic inperB, •■ A formula which will give good results by carefully working is as ollowB : — Middle hard gelatine lOOparts. Water (distilled) 1000 „ Bichromate of potassium 22 „ " Some workers prefer bichromate of ammonium instead of the potas- liam salt ; in this case only twenty parts of bichromate of ammonium ehoald be taken. "When the plates are thoroughly dry they are allowed to cool down gradually and are now ready for exposure in contact with the negative, which must be reversed, except where the reversal of the image is of no consequence. "The negative is placed in an ordinary printing frame. The collo- type plate is then brought into contact face to face with the negative under heavy pressure, and exposed by day or electric light in the ordinary way. The right exposure is known by examining the image through the back of the plate glass until all details show in a light brown tint. " After the exposure is completed the plate is washed in clean water nntil all the bichromate has disappeared. This is known by the absence of the well-known .vellow tint of the bichromate salt. " It is then allowed to dry spontaneously at an ordinary temperature. When dry it is ready for the power machine or hand press, but it is ad- visable, if possible, to keep the plate about two or three days ; the gradua- tion and half tone would be found more perfect. " After placing it in the printing press it is necessary to moisten the printing surface with a solution of glycerine and water, which la generally called the etching solution. The parts where the light has not acted the gelatine will absorb more moisture ; where the light has acted the gelatine has more or less hardened, and will resist the etching solution. It is kept on the plate about fifteen minutes, and then taken oH with a sponge and blotting-paper. The plate is then inked up with a gelatine or leather roller charged with stiff, greasy ink, similar to the lithographic process. The parts where the gelatine has absorbed the etching solution now refuse to take greasy ink, whereas in the parts upon which the light has acted the gelatine surface has hardened, and made them more or less in- soluble. They will not absorb the etching solution, and will readily take the greasy ink ; in fact, the greasy ink is repelled more or less in exact ratio to the amount of light acted on the plate, hence we obtain an image in all the graduations true to nature. " A considerable number of impressions can then be token off the plate, but after each print the plate must be inked up again ; and from time to time a fresh application of the etching solution is needed, otherwise the plate would gradually lose its power of repelling the ink. The printing part of the process requires a great amount of skill and experience to secure the finest results." At the conclusion of Mr. Kidd's address the various details of the process were all gone through in a thoroughly practical manner, from grinding the plate glass with emery to coating the plates with substratum, the drying of same in the large, accurately levelled drying chambers, the coating with the bichromated gelatine, and the printing by means of negative films stripped from the glass. The films having been previously coated with a solution of three ounces Coignet's gelatine to twenty ounces water, with ten drops glycerine added, stripped very readily from the glass plates (especially prepared for stripping by Messrs. Morgan & Kidd). The electric light was used for printing, after which the etching proce.-is was gone through and various wrinkles explained.- Great stress was laid on the necessity for proper inking, Mr. Kidd stating that very many proofs were taken sometimes before a perfect result was obtained, but when the right effect was gaiued a very large number of impressions could be pulled without any variation in quality. He pointed out that, for specially fine work, the hand machine was most suitable ; but, when using thoroughly good negatives, best results could be obtained by the larger machines, and as many as 100 impressions per hour could be produced when everything was in good working order. The leather rollers were used for inking the plates, and the gelatine roller for working the ink well over the impression. At the conclusion of the demonstration Mr. Cembrano called on every one present to testify their thanks to Mr. Kidd for his hearty reception of them that evening, and for the large amount of instruction every one had received. Mr. W. E. Debenham, on behalf of the visitors from the London and Provincial, endorsed Mr. Cembrano's remarks as to Mr. Kidd's kindness, and remarked on the public spirit shown by Mr. Kidd in making every- thing appear so clear and straightforward. Nothing at all appertaining to the process seemed to have been withheld, thus strongly contrasting with otner so-called demonstrations, where an inquirer, seeking for real information, often had to go away no wiser than he was before. Mr Kidd, in reply, said how pleased he was to have imparted any in- formation that evening, and how gratified he was to observe the attention that had been paid to the various details by all present. He would, how- ever, venture to remind gentlemen that, with all the instruction they had received that evening, perfection in the process could not be attained wiihoat a considerable amount of practice. A NEW EXP0SUR3 TA3LB. Messi'.s. Elliott & Sons, of Bamet, are issuing a system of exposure tables for use with their plates, of which they say : '• One of the leading features is, that we give f.>ur ^^ma!l illustrations of typical views, lettered respectively A, B, C, and D. A is a distant view witliout dark objects in forcgcouna ; B is also a vie.v with dl^taace, But there is liea'y foiia^je lu foreground ; C is a near architectural subject ; whilst D represents a moderately well-lighted interior. Portraits out of doors wouH require the same exposure as C, whilst portraits in ordinary rooms would require about the same exposure as D. The tables are calculated for 8top}-32, 74 THE BRITISH JOURNAL OF PHOTOGRAPHS. [February 3. 1893 but an additional table is given ahowinp; at a glance comparative exposure for any other sized stop. To use these tables, all that is necessary is to compare the subject to be photographed with the illustration, note the letter marked on picture that appears to coirespond with view, also note time of day and year ; then, referring to Table 1, under group of columns headed with corresponding time of day, follow down the column headed with letter on illusrHtion similar to view, until the line marked with re- quired month is reached, when the approximate exposure will be found." fi'-? 'M > CO r—. s a: o o _ h s r^ & c- ~o.-S - J3 a "o «-3 3 " .i * c-i " '= dz g g .- c 1^ ^ c3 ^ .^ •^ (U .^ "n .3 .= K S .X! ° O ..^ -^^ w E "m ^ .2 §.2 a oi ca «.-. a, 0 5=^ o.„ o « o^ • ■ '5 S .5 e! t^ U 01 C3 ■ ■^ M<1'~ S O.i to 3 'E * " j5 ^ c o n "^ >- S - , >^ fa S -5^ 3 ►? h^ -11 cc o 5?; P |a■■<^w OOci'H.-l'HrHc^'^OOcqin i : 0 -oag "o a -338 CQ rH W rH W ca OT ■" T 'MS 1 — * ,_( -^ rH ^ a -nire in lo in ci rHu rH ei 00 o O : 1 CdrH tJ,„ • '3 0 -sag -W.HN .HCT Oia(MrHrHrHrHr-*COHjfflOTrHrHrHCT..SiaDCqCD 'H pH CS CO a '358 ^S^.-,rH rHC^-^OOO \Y -oag CC rH rH (N CO H^ ] /a -urn :ino^f«incao ■ • • ■ (N -H rH CO : : : 1=1 00 -^ 0 'MS - C^ lO CO C , -4» -to -la -+J*F+*H*r« rtC eaX «(5, Mf., , «,j:r„fj'.Bj'j= .j;;-ia-4»->— .c:E Dirrctunis. — Compare subject to be photographed with illiiatrations, DOlfi time fil dny iiud month, refer to Table 1 under group of columns heuiled with conesponiiirc time of day, JoUow linwn the c.iliinin headed with the letter on i.lustr ition similar to view, until the Hue marked with lequireil month is reached, when the approximate exposure will be found. PLATINOTYPE UP TO DATE. Before the Bristol and West of England Photographic Association, on.' .January 27, Mr. Ed. Bnghtman in the chair, Mr. hlnclianan Wollaston, of the Platinotype Company, gave a demonstration of the working of the new cold bath paper, showing the great advances on the old hot bath process. The old paper cculd only be kept a few months, while the new- cold process paper in proper calcium tubes will keep for a year, and the Company had some which had kept perfect for twenty-three months, being longer than any other printing paper. A great advantage is the wide latitude in printing, so long as the paper is not under-printed, as even in a very much over-printed proof the result is quite under control by the help of glycerine in the developer. More- over, a print can lie artistically developed from a poor negative, by local manipulation. A complete black-and-white print (for copies of maps or plans) is obtained by the addition of a few drops of oxalic acid in the strong normal developer. Printing is carried out until the detnils in the highest lights are just visible in well-gradated negatives, and con- sequently printing is deeper than with the old hot bath paper. As long as any curl remains in the undeveloped print, after removal from the calcium tube, the paper is dry. The development witli normal exposures- of prints and normal solution takes thirty to forty seconds, but by adding glycerine and diluting solution with water, development can be much slower if desired. However long the print may be left in the developer, the image will not be damaged, but the ncid clearing must be mor& thorough. No means of destroying the image except hot iiqiii reffia has yet been discovered, and this proves permanency. The prints can be developed by immersion, by brushing developer on, and even by one's- fingers rubbing the solutions on, as touching any part of a print pre-, maturely with developer leaves no mark on tini^h ot development- With plain strong oxalate developer, inky blacks and cold tones are obtained. By diluting developer with two parts of water, slightly warmer tones. By taking one part of oxalate solution, one part of glycetine, and two- parts of water, and brushing solution on, much warmer tones. While by rubbing glycerine all over print first, and still further diluting the oxalate glycerine solution and using brush, the richest and warmest tones are obtained. To keep print flat during development, pour glycerine on a vulcanite- slab or sheet of glass, lub all over, and place print face upwards on slab,, smooth down, and it will stop there. Should the sky print through- with a thin negative, rub the sky and otber high lights in print with^ glycerine, brush on developer as usual, and the whites will be pure after clearing in acid baths. Hydrochloric acid (which must not be " com- mercial," but water-white) i^ better than citric acid, as the latter is hard to wash out of the paper. Platinotypes print three times as fast as- albnmen in summer time, and twice as fast in winter. Thin negatives- should be printed under pale-blue glass, and this produces blight, plucky prints. To get brilliancy, keep solution in motion with brush on print, and blot off after clearing and washing. To secure breadth in a flat-, print, brush foreground over with strong solution, middle distance with weaker, and far distance with still weaker solutions. To get soft efiecta- from a hard negative, take one part water, and nineteen parts glycerine, paint over print, which will absorb water, and develop as usual. In this- way half-tone can be secured from a negative which has none. The glycerine must be free from an admixture of citric acid, as sometimes- what is sold as pure glycerine by chemists has as much as thirty per cent, of citric acid in it. The acid wipes out the image as the clearing bath would if print were placed in it before development. Pictures dry a little- darker than they appear when wet, and this should be allowed for at the^ end of development. LOUTH AND DISTPJCT PHOTOGKAPHIC SOCIETY'S EXHIBITION. The Louth and District Photographic Society's Exhibition was openeJ!. on Thursday alternoon, January 2(i, to the invited guests of the Society, when there was a large attendance. The arrangements were cairied out by the Hon. Secretaries, Mr. S. F. Claike and Mr. Herbert C. Bentley, who were mateiially helped in their arduous duties by several members- of the committee. The pictures represented all departments of photo- graphic skill. In addition to a large non-compeliti-»e exhibition, to which. most of the best-known photographers of the day contributed, there was a members' competition for which Mr. S. F. Clarke announced that- thirteen members had entered. The Judge's awardswere as follows: — Silver medal (given by Mr. Mark Smith), Mr. H. S. Forman ; 2nd prize, Mr. E. II. Forman ; 1st certificate, Mr. Herbert C. Bentley ; 2nd certificate,.. Mrs. Fawssett. Mr. E. J. Wall, the editor of the Amiitmr Phnloqnipher, who acted as Judge, added the following to his award : — " The average quality of the work was decidedly high, and if the other two prints by ' Ominon ' (Mr. O. Burdett) had been equal to ,-1 liin iu the Clouili (another of Mr. Bnrdetfs) the set would have been very near the lirsu bes*." The Exhibition is said to have be^n a great social and photograp'iic success, the chief credit therefor being due to Mr. aud .\Ii-j. S. F. Clarir,. • whose illorts on its behalf were unremitting. Februory 1, 1891] THE BRITISH JOUKXAL OF PHOTOGRAPHY. 75 «©iir iBUitorial tHath. TiiK •• Rkliablk " Vkntilatoh. Mb. Hbniiy .Jonrs, II, Albion-stre»t, CovRntry, has sent us a sample of a ventilator he has introduceil for fixinir in {)hoto((rHphic dark looms for keepiajr up a supply of fresh sir, mucli iiesfled in some of the little 8tufTy pliices in which m\nv photo^iraphers are compelled to work. It consiat.i of a mill- board oblnno- cn-ie about ;i foot in lenfrth, an inch in thickness, and three and a Jialf inches in width, with a row of holes en the two opijosite sides ])>'rmittin2f free ingress and egreS't of air without the pissibilitv of li^rht heiuir transmitted, this beiiiff ensured by a lonpritudinal divisioa piec^ inside. It is attached to the •door or a piirtition in thediirk ro 111 l)v (t!inu:e-( ar each end, a spa"e beinir cut in such to c:)rreaark, S.fiL Brooklands Hotel, Brooklands. Club RfKim, Colonoadfl Hotel. 10, Rnehton-Btreet, Bolton. 376, Coldharbour-lane, Brixton. City Chamborn, Gaudv-gt., Exeter. 206, Mare-strtct, Hacitney. ManBion Uoncte, Hereford. Mechanics' Institute, North. street. Pitzrov Library, Hi^h-st., Lewts. Canonhury Tower. Tfd'nvton. N. Society's Rooms, 136, High-street. 9, G an xe-. street, Paisley. 5, Frederick-street, Rothtrham. Masonic Hall, Surrey-street. Victoria Hnll, (Toodnimpate, York. Art Gallerv, Ipswich. Mayor's Parlour. Old Towu Hall. School of Art, NeUou-place, Cork. Anderton'a Hotel. Fleet-street, K.C. The Stndin. 15, Cambridge-arcada. Mechanics' Institute, Stockport. y.M.C.A.,Grange-rd.. Birkenhead. Charing Cross-roail, W.C. 71, Proppec*- street, Hull. Chajnpion Hotel, 15, Aldersgat«-st Graresend. The Lyceum, Union-street, Oldham. Eooms, 28, Berkeley-sq., BristoL Public Hall,George-8treet, Croydon. Rooms, 15, Dawson-street, DnUln. "The Palace,'* Maidstone. Obifiwick School of Art. Chi»wick. LONDON AND PROVINCIAL PHOTOGRAPHIC ASSOCIATION. January 26,— Mr. Walter D. Welford in the chair. The Hon. Secretary read a letter from Mrs. Bedford thanking the members for their expression of sympathy witli her and her family in the death of Mr. W. Bedford. Pl.vtinum Toxinq on Ir.FORD "P.O.P." Mr. LtmiUMER drew attention to the following remarks in the January number of PhotuON inquired whether there was a i>ossibiIity of the platinum being substituted for the silver. The Platinotype Company were not able to use gelatine for sizing their paper in consetO(iraj'hy. At page 372 of that Appendix, after noticing the powdered copal or resin method, I said, " This method of producing a ground, however, was uncertain and troublesome, and was superseded by a much better and very ingenious method, discovered since tlie enrolment of the specifica- tion in 18.^8, and never yet published. Common resin and camphor arc dissolved in chloroform in proportions which may be varied. At the same stage of the process as before, namely, when the plate bearing the photo- graphic image is removed from the copying plate, some of this solution is poured upon it. The chloroform immediately evaporates, leaving a film of resin and camphor on the surface of the gelatine. The plate is then warmed over a spirit lamp, which causes the camphor to evaporate, leaving the resin in minute particles adhering to the surface of the gelatine. This method ensures a much more even distribution of the resin than the former." According to the greater or less proportion of resin to camphor, the ground was, I believe, coarser or finer. There were occasional small explosions of the camphor vapour during the plate-warming. You have yourself seen the beat results of the photoglyphic process of date 18U6, and I doubt if those results could have been obtained without the employ- ment of the above method. Also, my father's latest practice was to employ, not steel, but copper plates, and to have them afterwards coated with steel. I am not sulficiently familiar with the present use of photo- graphic words to know whether a cHche would be understood to mean a positive transparency in contradistinction to a negative. It is, of course, essential in the photoglyphic process that the exposure should be under a positive transparency. — I am, yours, Ac, C. H. T.vlbot. Lacock Abbey, Chippenham, January 29, 1893. DETERl^INATION OF PLATE SPEEDS. To the Editor. Sir, — Mr. G. F. Williams, in his article on this subject last week, goes out of his way to attack the accuracy of actinometers similar to the one associated with my name. Allow me to point out that, as far as I am aware, such actinometers never have been " seriously put forward with the hope that we could recognise them as even approaching what we seek in a standord," the standard referred to being an exact light standard for a standard speed system. The purpose for which such actinometers have been so extensively and successfully used for the past three years is to estimate the value of daylight falling on the subject as a guide to the length of exposure to give a plate. For this purpose hundreds of practical photographers, including some well-known names among the "older race of photo- graphers," have found the use of a bromide of silver actinometer far more reliable than the old rough and inexact method of estimating light by the eye, aided with experience. A very small amount of investigation shows that simlight, as it reaches the earth, varies in its properties from time to time quite as much as many artificial lights vary from average sunlight. It is plain to me that an artificial light will have to be used if a standard system of speed determination is desirable, and I should be the last to advocate the use of an actinometer in this connexion. With a reliable standard light the amount of light received by the plate should certainly be judged by the standard of time, and not by the readings of an actinometer, which, how- ever accurate, would be a useless complication. Of coarse, this artificial light should be as alike as possible in its spectrum to average sunlight. Mr. Williams' statement with regard to supposed errors caused by the use of actinometers, that " it is at all times possible to multiply the error ten times or a hundred times," is absolutely untrue. If an actinometer is used as a guide, either for time of exposure or for speed of plate, and there is an error in the estimation of light of, say, 25*/,, the resulting error in the time of exposure, or in numerical speec" of pUte, will be 25 °/„, no more and no less, unless error from some other source is introduced. Surely it is unnecessary to point out that an error of one second in a tour-second exposure, is identical in value with an error of ten seconds in a forty-second exposure, and the same thing applies to speed numbers. I do not think Mr. Williams does justice to the importance of Messrs. Barter & Driffield's investigations. It is very easy to pick out the weak parts in their method as now applied (I have done it several times), but it u only right to recognise that they were the first to point out the way in whioh the graduation sensitiveness of a plate could be ascertained, and their method, although perhaps in some other form, is certain to be utilised in the standard method of the future. It will, in my opinion, be necessary to recognise that the quality which we sum up in the word " sensitiveness " is a complex one, and cannot be accurately expressed by one numerical value. Just as Warnerke's system made the mistake of presuming that the ilemity-ijiv'mg speed of a plate is all we want to estimate, so Hurter * Driffield wrongly presume that the photographer only wants to know the graduation speed of a plate.— I am, yours, uhlication, otherwise the Exchanges will not he inserted. Will "xfibanye SCO) aivh-de-vinitemowatn for a eight or nine-inch condenser.— Address L. Ward, 2, 6ta.tiou-road, West Croydon. Will t'xchanee eisrht-incli ca.'? bnrnisher as jrood as new for whole-plate camera.— Ad- dreris, J. Behhett, 38, James-street, Swansea. Wnnted to oxchansfe two microscopes (DoUoud'f) for 12x10 ontftt.— Addreas, J. G. Pa«r, H, Richmond-gardens, Shepherds Bush, W". Kxehanire 10 xH burnisher by Rock, ■ heffield, for 5x4 rapiil rectilinear.— AddreBs, J. Taylor, 19, Castle-street, Dulltown, Baiitfghire. Wii; exchange British Journal of Photoukaphy, over peven yeara, for haU>plate or lar(r.'r earner*.— AdJresH, T. Mi;iR, 43, Nethcr^tte, Dundee. Harfwich'a Vho^op-n^ihir Chemi-fi-ij in exehange for Taylor's Photographic (>}>tic:^.— Addie^i-, J. A. O. MuKUAT, 3, Kightiujirale-tiJi-niee, Sutton, Surrey. Wanted lirgt-chi.s? lantern or hand camera for HaliKf's ten-jruinoa medical electric Itattery.— Addres.s, Akthve Pearck, 11, Waterloo-crescent. Dover. iBinnial (foni-inch ooudi-usersj, portrait IcuriPfJ, dissolver, and jets, fffts bag'. &c., ex- chausre for c-imera or leui-es. — Addruss, H. Allbkkjht, 135, London-road, Orojdon. Stove, powerful and h»n, Londou-road, Croydon. Will exchfiupe burnisher, nine-inc!i rolI*-r, fcr a rollinc pres«, or will make enlarjire- ineiitsand tiaisH in oil ur black and white for same.— vVddreo.-, A. Hamilton, Artist, Kmsrsd.iwii, BrJBtnl. I will eftchan),'c a 5x4 qack-aftinc portrait lens by Ro^« for a 7x5 optimns eury- i Mope, iris d»«pkragm.— Adares*, Williamson Eu^lei. Whitelandg, Little London, ' ttAivdoii, near Leeds. IWill exchange Tue British Joirnal ok Photo'ibaphy from April 1390 to end of ^ 189- (141 nuinbertj) tor phun baUftKrunnd or burnicher,— Adcrets, C. GoDyuEY, 23, f LiLvae-road, Pouge, S.K. Ill excharme an eiirhtkeycd flute (by Monzani). silver Iters and fittinps. for a cabinet porr I ait Wm hy jood n.ukur.— AddretK, H. & A. f i.OAiir, PLotouitiphtrt>, a»0, Mi;rli-ji.n-tr, yirrttio»-d. |Ela]iancre for a4i> Dallmeyer lens equivalent value of th« fnllowtne len»ef>:— 2b Dall- meyur; 1a Dal.muytr wideautfle lens, patent ; a Orubb p. lent landscape lens.— «il'U-et>*, MclsAAC & RiiiULir, btudio, i;bau. ' Will exohango lanre rapid 10x8 portrait lens for 9x7 Optimne XnryMOpc 1«im wttb Waterhouw stups, or 7x5 as u above with Trts diapbrMfrms. Spcoimeo of work .tent.- Addrefl^t, J. R. Hmitx, rhotc^apher. Little London, Kawdon, near L»6d«r Yorks. Wantor-road, ,). Thames. Will exchaufre a uearlv new Russian iron nia^c lantern, with travelling ra^e, ftttinf(» for oil or liraeliphl; al«o French cabinet portrait lens, good for large head*, for Lancaster's faalf-plato 3392 or 1893 inst&ntugrapb set.— Address. W. BoKb, Aank Plain, Norwich. Will exchange Harrison's patent head and body rest, and Fcholzig's graduated bn.it vignette Viackground and stand, both new, for half-plate Instantoirraph, or other outdoor set. Good pocket revolver taken. — Address, J. MAtreet, Cardiff. EnstocrsJ to tforrespontients. *,* All matters intended for the text portion of this Journal, including gneries and Exchanges, must lie addressed to '' Thk Editor, The British- Journal ok PHOTOOHArHY," 2, York-street, Covent O'arden, London. In- attention to this ensures delay, *»* Correspondents are informed that ice cannot undertake to answer com- munications through the post. *,* Communications relating lo Advertisements and general business affairs- should be addressed to Messrs. Hkhky GUEENWOoii & Co., 2, lurk-street,- Covent O'arden, London. Photoukaph Kkoistkkkli : T. S. Hicks, Sheffield.— Photop-apli entitled, Jolm Buil and his Pal. G. S. D. — A single lens can be used in the manuer and for the purpo.se you describe. E. M.— The electric retouching desk can be obtained of Mr. C. A. Jtudowskji- of Guildhall-chambers, E.C. Qux. — We have had no experience in that class of busines.s. Better conanlt some one conversant witli the practical working of the system. J. H. Bow.MAX. — Mr. E. Duumore has an article on " Lauternslide Colournig" in this JoiiiXAr. lor November 4 last (see Supjilenient, page 10). W.M. Fknton Jones. — Metol is not, so far as we are aware, on sale in this- comitry. Po.ssibly Messrs. Fuerst Bros, would procure you a small quantity irom Germany. T. Molten.— The most rapid lens for lautern-alide negatives is what is known as the instantaneous stereogr.ipli. It Is a moditication of the Petzval len.s, and has an aperture of about y'-iJA. May (Ayr) writes : ■' Would you kindly tell me in your leanied coiTesjiondenca the lirst day of spring in England ; "— Accordiiig to the almauiics, the first day of spriug in Eugland is Marcii 21. PiiiNTKit.— Possibly Mr. Buchanan WoUaston's remarks on the subject in the present numlier of the Journal will assist you. We have not heard of any previous complaints of granularity with the new paper. , Sandown. — Any view that is taken direct from nature cuu be made copyright, notwitlistanding that it may have been pliotographed scores of times Iroiii- tile same spot and each of tiie photographs maae copyright. A. Pkahce. —We cannot account for your failure. We do not think there is • any advnntaze in the use of recrystallised carbonate. Give us fuller details ot your met lod ol working, and we may be able to assist you. A. J.— 1. Tlie addition of Venice turpentine to starch usetl lor mounting is net likely to act injuriously on the lihotograph. 2. The frames can probably be had from Marion 4; Co., or any of the other dealers iu photographic gootls. E. GooDKKLLow.— If, upon the addition of a little permanganate of jiotash to tlie water, the red colour of the permanganate is convertetl to one of lirownish hue, then is the water coutaniinated with organic matter, and uut tit lor drinking purposes. A. Bkn asks : " Cm you tell me how to put the gilt line on the outside of cut njounts. usually about a halt an inch Irom the opening ;" — The gold is put iu with a ruling pen charged with gold paint. Uold pamt ready lor lue is supidied liy all artists' colourmen. G. W. ANDliEW.s.— Vou had l)etter get a m.innal of the carbon process, sucll as that i.'.sued by tlie Autotype Company. That wUl give you the iuforma- tioii leipured. riavinggot ugener.il idea of the principle.', of the i>roce.i3, you wjil then haxe no dllHculty lu jtrodticiog carbon pictures. 80 THE BRITISH JOURNAL OF PHOTOGRAPHY. [February 3, 1893 Anxious. — By no mean-s go to South Australia, where we have reason to believe things are in a had way. Possibly you would find South Africa a better locality in which to secure photograiihic or picture-frame-making employment. Ask your doctor if the climate would be suitable. O. Osborne. — As cochineal colours, such as crimson lake, &c., are fugitive by exposure to light, and they were used in matching up the tint for spotting the prints and working up the enlargement, the fading, or changing of colour, after six months' exposure in the show-case, is fully accounted for. J. H. G. — Eighteen or twenty inches will be a suitable focus for such a lens as you need. Not knowing the focus of your 9x7 lens, we cannot give you the measurements desired. W'itli reference to the electric queries, Whittaker & Co. publisli several cheap works devoted to tliis topic. Write for a list. C. H. — One of the best papers to be had for the purpose — that is, the best an amateur can obtain in small quantities — is Whatman's or Hollingworth's rough drawing-paper. 'Hiey have not exactly the surface of the sample enclosed, but the papers themselves are otherwise better suited for photography. E. Gregson \vrites : " Could you inform rae of a recipe for imitation of ground glass for studio top and sides — one that can easily be cleared off in winter ? I am very much troubled with tlie sun." — Make a mixture of starch paste and whiting, and stipple over the glass with that. It can easily be removed with water at any time. Kalph. — 1. What you say is perfectly correct. Every one knows that a clear white sky in a lantern slide is better than badly put-in clouds, hence there is no necessity to insert your letter. 2. Enlarged portraits, if they exceed life size, are very unsatisfactory. 3. Make an enlarged negative, and print either in carbon or platinotype. Carpathian. — We think tliat either of the cameras mentioned would suit your purpose quite well ; but if we recollect aright, " A " is not adapted for a roll holder. Your supply of lenses is quite sufticient for every purpose. These is no difficulty in producing enlargements from films, any more than from glass negatives. We have always used No. % Leg.vl. — So far as we are aware, there is no special law relatiu" to photographic stiulios. If premises are taken on a repairing lease, and a photographic studio is p.art of them, of course that is includeortraits ? He .says lie often takes the portraits of his friends, and they ask him for copies, and wants to know how mucli to chiirge so as to make a little profit on the work for his trouble. — In reply, amateurs make no charge whatever to their friends ; if they did they would cease to be amateurs and Ijecome professionals in disguise, such as is our correspondent. In arranging his charges, he should be guided by the price lists of boiiA-fule professionais of his neighbourliood, witti wliom he appears to be competing. P. Smith says : "1 .am an old amateur, and am tolerably familiar witli wet collodion, with whicli I was able to take very fair negatives. I have recently gone bacli to that process for lantern slides, though I never made any by it before. I get on very well, but the slides, wlien dry — tliey look all right while wet — are more or less oiialescent in ajipearance. It is not fog. Can you suggest a remedy {" — This appearance is by no means unconmion. It can entirely be got rid of by varnishing the slides witli oniinary negative varnish. They will then be the same as they appeared wliile wet. A. W. Neame says : "I am only an amateur, and was called from home for three weeks the day after making up a new acetate touiug bath. Wlien I went to use it a few days ago, tlie sides of the bottle were covered with a dirty, bronze-like coating, and there was a mnddy deposit at the bottom of the Ijottle, and tlie jirints will not tone with an hour's immersion. No prints had been toned in the solution, so the paper could not have injured It. Why is it in this condition ?" — The reason is that the gold has, by some means or other, become reduced Ito the metallic state. Impure water, an imperfectly cleansed bottle, &c., may be the cause. A long exposure to light will also bring about a reduction of the gold. CooNTRVMAN writes : " I Iiave been consulted about supplying a dozen en- largements, 15 X 12, of a deceased person, one of a group on a little glass positive. They will retpiire a great deal of working uji by an artist to make them at all good, and this, 1 tear, will make them too costly forme to secure the order. I can make the enlargements myself, liut it is the finishing that troubles nie. Can you give me the benefit of your advice ( " — We should suggest that an enlargement be made, sty, twenty or twenty-four inches, and this be well finished by an artist. From this a negative should be made the size required, then the prints would require no work upon them. It is i|uite possible that some of the friends of the deceased would purchase the finished enlargement. Thos. LaMbeli. writes as follows: "Canyon give me any information with regard to the enclosed print, and how 1 can restore it and about a dozen others like it to its original condition, which was that of an ordinary albumen print ; The facts are these. A cu-tomer of mine, who has tieen travelling on the Contiuent, brought home a number of views mounted on cabinet cards, and I undertook to take them off and remount them in a scrap album. Three or four dozen came off all light as usual, but about a dozen, after soaking with the others, liecaiiie opalescent in appearance like the enclosed, and, as you see, this hides the iletail. These jiarticular jirints I noticed before I put them into water seemed to have a more artificial gloss than albumenised prints usually have. Any hints you can give will be appre- ciated, as I fear I shall get into trouble with my customer." — The ])rint in question is not a silver one, but a collotype on "surfaced paper" that has been glazed with an aqueous solution of lac. The only treatment we can suggest is to remove the old glazing by soaking the prints in spirit, and re- glazing or varnishing tliem. West London Photographic Society.— February 7, Technical Social Meeting. Photographic Club.— Febniary 8, Members' Open Night. 15, Bmne-mmle Apparatus, Mr. William Tylar has removed to new premises at 41, High-street, Aston, Birmingham. Messrs. 0. Sichel & Co. have removed to new West End show-rooms at 47, Oxford-street, W. We also announce the death of Mr. Henry Dixon, the well-known photo- grapher of Albany-street, in his seventy-third year. We are sorry to learn of the death of Mr. John Harmer, of Littlehampton, who for many years past was a frequent contributor to this .Ioubnal and its Almanac. Hackney Photographic Society.— February 7, Ladies' Night ; A midol de- nwtistratioii and J'rir^ Slides. 14, Photographic O/iemicah, bv W. H. Sodeau. 21, Lantern-slide CoZowrtnj (adjourned), by S.J. Beckett. 28 Prize Slides. Leytonstone Camera Club. — February 8, Lecturette, The Optical Lantern : its structure and Its icses, by Mr. A. P. Wire. 15, Demonstration. Lantern Slides and how to make tli^m, by Mr. H. E. Farmer. 22, Members' Lantern Evening. London AND Phovincial Photographic Association.— February 9. First Technical Lecture, The Lens. 16, Demons'ra'ion of the Air Brush, by Mr W. H. Harrison. 23, Annual Musical and Lantern Entertainment. Ladies' night. Mr. J. Traill Taylor in the chair. The premises at Kingstonon-Thamas, lately occupied by the Fry Manu- facturing Company, will be sold by auction at the Southampton Hotel, Surbiton Station, by Messrs. Maddox & Son, at four for five o'clock on Wednesday, February 15. Messrs. Arthur Schwarz & Co. inform us that from this date they are the sole agents for the products of the photographic department of the Actien-Gesellschaft fiir Atiilin Fabrication, Berlin, who are the manufacturer' of Dr. M. Andresen's developers — eikonogen, rodinal, and diamidojihenol. On Friday evening last, January 27, the Photoeraphic Club g.ave an enter- tainment to the children of memliers and friends, which was numeron.'ly attended by the small people invited. The bill of fare included slides humour- ous and otlierwise, singing, pianoforte-playing, ventriloquism, conjuring, ^"•. all of which gave unmitigated delight to the audience, each member of whioli, on departing, was presented with a parcel of sweets contained in a box having the form of a hand camera. The Londov County Council and Bill-posting. — The action taken bv tlie London County Council in reducing the height of posting hoard'n?" to twelv>" feet hrs had a widesjiread and disastrous result, and at a recent meet iig of tie Manchester branch of the Amalgamated Society of Lithographic Artists. Designers, and Writers, and Cojtperplat* and Wood Engravers, if was resolverl "Th.it this meeting is of opinion that the restriction made by the Loudon County Council is cilculated to do a serious injury to business not only in London, but in many large establishments outside London." We are informed that the National Association of Professional Photo, graphers will hold their second annual meeting at the Grnsvenor Hotel- Manchester, Thursday, February 9. Chair to be taken a' 7 p.m. liv the President for the year, Mr. Thomas Fall of London. The Council will meet at 2 p.m. same day, and same place. Only members whose subscripti'ni-' are paid \\\i ar.^ privileged to attend and t.ake part in the proceenrtant matters will be laid before the meeting, whi :h it is hoped in the iutfrests of the jirofessioii will be a large and influential one. Conmiunications to be addressed to the Secretary, D. J. O'Neill, 47, Charlotte-road, Birmingham. The annual onrersaaione of the emplo^ifs and friends of Messrs. Georgo Mason & Co. took place in the Assembly Rooms, Glasgow, on the evening of Wednesday, 25th ult. With Mr. Mason us chairman, whose .1bi'it^■ in a social function of this kind is well known, with Mrs. Mason's kind lielp and the aid of un energetic Committee, the "uccess of the reunion was a-sured. " All went merry as a marriage bell." The music was excellent, the floor in maiiniticent order, and the forty couples who tripjied the light fantastic till well on in the morning left with a decided sorry-to-part-happy-to-mfet-agaiii feeling. Songs were given during the evening by sever.al ladies and gentlemen, Mr. J. L. Cox excelling himself in the delivery of "True till death" ami "A warrior bold." OONTBNTB. Paok stereo-micrography 115 retouching and varnishes 6f. has PVROUALLIC acid BEEN DIS- PLACKD? Ill H. W. VOGEL, PROF... 07 photographing PAINTINGS by;arti- FICIALLIQHr. By W. E. PEBENHAM r,S determination of plate SPEEDS. —11. Bv O. K WILLIAMS 09 A CHEMiCU. STUDY OF MERCURIAL INTENSIFICATICIN. Bv CHAPMAN .T(>Np;s F.l C. F.C.S 70 THK HAND CAMERA AND ITS USE IN PICTIUE-MAKIXG. By W. THO.MAS. . 72 Paob A VISIT TO MESSRS. MOBGVN D, KIDIIS COLLOTYPE WORKS AT RICHMOND 71 A NEW EXPOSURE TABLE Ti PL.\TIN0TYPE UP TO DATE 71 LOUTH AND DISTRICT PHOTO- GRAPHIC SOCIETY'S EXHIBITION.. 7 1 Ot:R EDITORIAL TABLE 7 . RECENT PATENTS MEEriSGS (^F SOCIETIES 7 FORTHCOMING EXHIBITIONS '■• CORKKSPONDENCP '■''' F.XCHANGE COLUMN ' AN8WEB8 TO COBbESPONDEMIS 7,i THE BEITISH JOURNAL OF PHOTOGRAPHY. No. 1710. Vol. XL.— FEBRUARY 10, 1893. VALUE OF GOODWILL IN PHOTOGRAPHIC BUSINESSES. An inquiry appeared in our correspondence columns a few weeks ago as to the value of the goodwill in a business at the seaside. In reply thereto one correspondent, on the data given, values it at from one thousand to eleven hundred pounds — or equivalent to about the stated profits for three years. Another correspondent estimates its value, practically, at nil. The discrepancy is great. Three years' purchase certainly seems a very high estimate for the goodwill of any pboto- gi-aphic business at the present time, and we have little doubt that many photographers would be only too glad to dispose of their businesses on much easier terms than these. The con'cspondent who gave the low estimate, last week, quotes figures, in a businesslike way, to substantiate his idea of the profits on a return, as stated, of 850/., and it must be admitted that he has not been over-liberal in the matter of expenses — wages in particular. The salaries of a lady for the reception-room and a printer, for instance, are only put down at fifteen shillings a week each, and a boy at five shillings. The computation leaves about 220/. only as profit — about the salary of a really good operator. If this return be accepted, it 8ho\*8 that the goodwill is not worth buying, as the profits do not exceed the salary a purchaser would receive as an employe. Since the query first appeared we have made some inquiries amongst those we consider competent to give an opinion on the subject, and we find a great diversity of ideas amongst them. One and all, however, agree that, for an ordinary portrait business, anything like a three years' purchase would be quite out of the question, and that one year's profits, in the present depressed state of the profession, would, in some cases, be too . much, and in others the stock, plant, furnitaws. — The Austrian photographers are up in arms against a movement to limit the time of protection to pictures produced by means of photography to a period of five years, and in a recent number of the Photof/raphische Correspondenz Dr. Eder states that, having at different times been approached by photo- graphers as to his views on the subject, he regards five years an insufficient time. He is, and always has been, of opinion that not only photo-mechanical positives, but all other kinds of photo- graphs, should enjoy (i longer period of protection, and he denies that he has ever expressed a contrary opinion. Photo-mlcrog'raphy and Industrial Hygrlene. — The Imperial High School of Photography in Vienna has, it is said, com- pleted some photo-micrographic work of great importance to the hygiene of industry. It has been sought to study and determine the influence of metallic dust, &c., on the health of workmen. Micro- scopic examination was made of the several kinds of dust to be found daily in factories and workshops, and the High School, at the request of the authorities, took photo-micrographs of all the samples examined. The pictures, with explanatory text, have been published by the authorities. The negatives were taken by Herr Valenta, and comprised forty-eight photo-micrographs, which were reproduced in phototypy and are said to be of great interest to those studying the diseases of workmen contracted in their labours. Conunon Salt In Mercurial Intensification. — Before the Soci«to Fran9aise, MM. Torres Freres, of Mexico, lately brought an intensification process which allows the plate to be bleached with mercury without having been submitted to jierfect washing after fixing. It consists in the avoidance of the yellow stain, which would thereby be produced, by placing the fixed plate slightly washed in a solution of common salt 1 : 100 for about half a minute. Intensifi- cation then proceeds as usual. STATUARY PORTRAITURE— HOW MR. C. W. MOTES OF ATLANTA, GEORGIA, WORKS. I ERCEiVBD to-day your Journal of the 6th inst., in which I find your leading article describing the illustration in Wilmu's Mayaztne, "Sisters of Bethany." I desire to thank you for your excellent notice and for your high endorsement of my effort to produce something out of the " threadworii paths " of photography. I assure you I appreciate your opinions of my humble effort, and will place a higher estimate on the picture than heretofore, and it stimulates me to make stronger efforts to advance. I have mailed to you an unmounted print from the original negative, which I trust will reach you eafely. In regard to your criticisms you are right, but I desire to say we cannot always control our subjects as to styles. If bangs are in style, they cannot be induced to pose without bangn, as was the case in this picture. The style of the dress I had to leave with them, and they msisted on short sleeves, and the one standing, on plenty of under- skirts. I tried to persuade her to remove her skirts so as to get rid of the bungling drapery behind, and show her form by having the drapery cling, but she would not, so I had to do the best that couU be done under the circumstances. The one fitting obeyed my sugges- tions, and I think did her part well. I do not claim the grouping to be entirely original. I had frequently seen and studied an engraving similarly posed, and had it in my mind when I made this. I mention this, fearing some one might accuse me of claiming originality in the composition. Now, a word as to my methods in making this class of work. For background I prefer black velveteen ; it is important to have the oap run upwards, so that the reflection of light is prevented. Incline the ground from the light, and the result (if not over-exposed) will be almost clear glass. I have three widths in my ground, seams running up, and am nevor troubled with seams showing if, as stated, the ground is inclined slightly from the light. In order to produce satis- factory results, it is absolutely necessary to use a black ground ; and, if by unavoidable circumstances there is reflection on the ground, it can be removed by the method you describe without giving the cut- out appearance, which will invariably be the case if made on an ordinary background, especially around the head. Again, when made on black ground, I have frequently removed all the ground with a knife cutting around the figure. Frequently parts of the drapery that may be objectionable can be cut away, and made to conform ts the taste of the operator. In this case I use a very sharp knife to bevel the edges of the film, to prevent it printing too sharp. For the pedestal I use wooden boxes covered with musUn. Coat with glue, and, while wet, sprinkle with sawdust ; when set, knock off excess, and paint with colour to suit taste to represent granite. I then paint name or title on box, and shade so as to represent the letters cut out. In my exposure I work for the shadows with a strong diffused light. Time with great accuracy — too much time will sure ts produce flatness ; too little black shadows are very objection- able in this style and lose the effect of marble. I have taken the liberty to be rather lengthy, as there seems to be some misunder- standing as to the methods I use ; so, in the event you have occasion to refer to the matter, you can condense such as suit your purpose. Atlanta, Ga., U.S.A., January 27, 1893. C. W. Motes. [We have received the unmounted print of the group, which is excellent. From the number of communications we are having, we are warranted in surmising that statuary por- traiture is a subject of considerable interest to professipual photographers — in England, at any rate — and doubtless the practical details of working, with which Mr. Motes supplements our article of January 6 last, will be highly appreciated bj them. — Ed.] JOTTINGS. On January 27 I remarked that I had often wondered whether th« phenomenon of shearing stress could be turned to practical account, and I added that the same thought had occurred to me on the recent publication of Mr. Carey Lea's experiment proving that great mechanical pressure alone was sufficient to darken the silver salt. A writer in a contemporary publication says that on October 12 last he said, " the experiments pointed to new possibilities in the way of priating. A slightly photo-engraved plate may give a developable image by simple pre.ssure." Now, any one having the least photo- graphic knowledge can see that these quotations are not at all parallel ; but, as the writer appears, from the context of his remarks, to be deluding himself with the grotesque belief that his pages are the source of my inspiration, and, notwithstanding that I studied and wrote on the phenomena of shearing stress shortly after Captain Abney published his experiments some years ago, I hereby make over to the writer in question the full, absolute, irrefragable, undiminish- able honour of antedating me by three months in the suggestion that shearing stress or darkening by pressure might be useful for repro- duction purposes. .\t the same time I regret that, having no time to dispose of in the habitual perusal of the periodical upon which hit 86 THE BRITISH JOURNAL OF PHOTOGRAPHS. [February 10, 1893 literary and scientific acumen confers a distinction that requires to be much more widely known to be appreciated at its proper value, I had no means of discovering that modern knowledge had received this epoch-marking addition on October 12, a date which henceforth should be printed in red letters in every scientific calendar and almanac. " It signifies nothing," plaintively proceeds the gentle scribe, " this perhaps unconscious assimilation of our matter, unless one has regard to the fact that an affected ignorance of even the existence of other photographic (sic) journals is a flattering unction much indulged in by our aged contemporary," &c., &c., and so on. I am unacquainted with the peculiarities of the process by which a journal, youthful or aged, "indulges" in "a flattering unction;" but it is quite plain where the shoe pinches. You " affect " ignorance of " other photo- graphic journals," his amongst them, and so, because like a sensible Editor you do not give free advertisements to all or any of the obscure hangers-on to the coat-tails of photographic journalism, the dictionary is ransacked for such laboriously manufactured epithets as " uncon- scious assimilation," and a whole column of the valuable space of this self-styled " vanguard of technical progress and invention " is taken up with a laughably hysterical denunciation of you and all your works. " Well, well," as the burly farmer said when his wife and mother-in-law, as was their custom sometimes, gave him a good drubbing, " what matters ? It amuses them and doesn't hurt me." And 30 you may say ! But, alas ! that the world should " know nothing of its greatest" journals, and that the " vanguard of technical progress and invention " is condemned to make the welkin ring with lamentations, because its more aged contemporaries will not fold it to their manly bosoms ! It is fortunately a cariosity of journalism that mud should be cast at the forty years editori^ reputation of a paper simply because the jottings of an occasional contributor do not gain the approval of the editor of another journal, and I should not have ventured upon this rejoinder had I not beeusthe unwitting cause of the screaming and foaming at the mouth in which your contemporary has indulged at your expense. But, besides this, I have another object in view, and that is to discover the actual writer and the cause of his animus. He commences some twenty lines of unprovoked and clumsy Billingsgate with this re- mark : " But, of our own knoivledge " (these are my italics), " we have not the slightest hesitation in comparing the accumulated tomes of the above quoted journal" (that is, Tub Bhitish Joubnat, of Photo- graphy) " to a waste-paper basket of antique and ample build — the repository of an unequalled weight of cameristic verbiage," &c. I wish to direct the attention of the reader to the italicised passage. Such a degree of knowledge, especially when it is read by the light of subsequent remarks by the writer, implies' an acquaintance with the " accumulated tomes " of this Jouknal such as cannot be possessed by anybody save its Editor, or somebody who has been compelled to make a close study of those volumes for, let us say, bibliographical purposes. Again, the writer dubs himself " an energetic inquirer into photo- graphic facts." What kind of facts, I should like to know ; scientific or historical ? I can scarcely believe that the deplorably immoderate language I have quoted is the utterance of any self-respecting editor, or that he could have been aware of the nature of the copy he was passing. It could only be the work of somebody who nourishes some private resentment against this Journal and it« staff ; some disap- pointed would-be contributor; some lurking bandit, like the " English " journalist who was recently exposed in these pages for a series of underhanded attacks in an American paper on English photographic men and things ; some " Talbot Archer," in fact, of whom I wish your contemporary every possible joy. I am glad to see that Mr. W. Thomas, in his able and practical paper on The Hand Camera and its Use in Picture-^nakiny , emphatically challenges the contention of many writers that a finder with a hand camera is unnecessary and useless. Some users of a hand camera are, 1 know, fond of airing their cleverness by saying that they can tell or guess when the object, moving or otherwise, they are pointing the camera at is in the field of view ; but in the former case a great deal of skilful judgment is required to ensure anything like reasonable certainty that the picture has not " passed the plate." As Mr. Thomas says, " finders are necessary if you desire to ascertain that your main object of interest takes its proper position." In hand-camera work all uncertainties should, as far as possible, be eliminated, and there- fore I endorse all that he says on the subject. As well do away with a focussing scale in a camera of variable focus as a finder. Mr. Chapman Jones, at the conclusion of his paper on mercurial intensification, points out that the success of his process of intensifica- tion with mercury and ferrous oxalate depends upon the removal of the hypo that may remain in the plate after washing, which he says can be done by soaking in an acidified alum solution. On the assump- tion that hypg alone is present, has it been demonstrated by experi- ment that the solvent powers of water are insufticient to effect its removal, or is the acidified alum necessary for taking out the silver hyposulphite, which is possibly present wherever the hypo is ? Would Mr. Jones recommend acid alum in preference to peroxide of hydrogen as a hypo eliminator ? In connexion with the stain caused by intensify- ing a film from which the hypo had not been thoroughly i-emoved, it would be interesting to know whether the hypo j^er se, or sodium hypo and silver hypo, are the cause of the stain. If the presence of the latter is essential to the production of the stain, then imperfect fixation is at the bottom of the trouble, and a fresh bath and hypo is neces- sary, unless silver hyposulphite is soluble in acidified alum. It seems to me that our information on these points is very meagre. Cos.Mos. 1 ♦ I X0TE3 UPON THE USE OF AMIDOL FOR BROMIDE WORK. Whilst it may be said of the use of pyrogallic acid for negative work that not one of its competitors has ousted it from the foremost position, it is still more true of ferrous oxalate that up to the moment no other reagent produces finer results for bromide work, or produces them more easily. The use of an acid fixing bath in place of a simple solution of hyposulphite of soda does indeed enable good results to follow the development of bromide paper by hydroquinone or eiko- nogen, but it only substitutes one great difficulty — the use of an acid clearing bath previous to fi.xing — for another, viz., the doubt as to the stability of prints made by its aid. The use of an ante-fixing acid clearing bath has always appeared to me the weakest point of bromide work. I have never been able to see my way to advocate its use, although I am quite ready to admit the excellent results attained by its aid, and even tempted by the fatal facility of the means to resort to its aid at times. But, notwith- standing this inconsistency on my part, I regard as a distinct, evil the practical necessity of its use to prevent an iron deposit and stain on the paper when the oxalate developer is used, for it is indispensable that this acid solution should be entirely removed from the pores of the paper and film before the picture is placed in the fixing bath. This complete removal seldom obtains in practice. It is true that by careful working a considerable degree of purity of colour may be secured without the ante-fixing clearing bath, but the results are more difficult to obtain, and hence I assume that it is largely used. My point — a strong objection to the use of an acid clearing solution before fixing — is admirably enforced by the printed instructions issued with a popular make of bromide paper : " All the acid must be removed, or fading of prints will result." It seems reasonable, then, to welcome the advent of any developer which offers a chance of escape from this inherent weakness of the process of development by ferrous oxalate, and I tried a sample of amidol with which the agents in this country had supplied me. I must say that doubt possessed me on the ground of the somewhat fulsome praise bestowed upon the last new thing, which for negative work I feared less useful than pyro. Besides this, a one-solution developer always raises one's prejudices. Following a custom more honoured in the breach than the observance, I made up a quantity of solution strictly in accordance with the maker's instructions, and using a sample of sulphite of soda which they supply for use with their developer. This is an excellent idea, as considerable variations occur in different samples of sulphites, and if a caution were added to the instructions to use the maker's own sulphite, it would be better still. I did not meet with success with the solutions so weak as the makers recommend. The pictures were flat, and always appeared to be over-exposed. Temporarily, therefore, I abandoned making pictures, and, instead, exposed several pieces of paner behind a Spurge's sensito- Februaiy 10, 189.'J] THE BRITISH JOURNAL OF PIIOTOOaAPHY. 87 meter, a useful little instrument, which enables one to save much time in experimental worlc wlien it is doubtful in which direction success or failure lies. It was now quickly apparent thnt the scale of f^datiim wns not marked enough. Intensity of deposit was lacking in the long exposures, and there seemed some indications of the action of light right up the scale, as if the developer were extremely active to the least-exposed parts — as, indeed, I think it is— and insuiiiciently so to the others. My experiments were interrupted at this point, and, as the bottle of amidol developer was accidentally left without a cork, I was able to observe that the action of the air for twenty-four hours was to slightly colour the solution, a state of things which might be e.xpected with a one-solution slightly alkaline developer. It did not appear, however, to have lessened its developing powers, or to have rendered it liable to stain the paper — points which I noted with surprise. Taking up the experiment again, I now tried th» maker's formula undiluted. This stands as follows : — Sulphite of soda . .4 .^ 800 grains. Amidol : 80 „ Water 8 ounces. Allowing for the increase in bulk by the addition of the solid consti- tuents to the water, this approximates to an eight-grain solution of amidol. In my earlier attempts this had been diluted with three times its bulk of water, in accordance with the printed instruction. With the stronger solution I obtained much better results. The deep shadows were richer, the high lights purer. But development was too quick : in fact, the picture rushed up and was over-developed " in a hurry." Compared with pictures developed with ferrous oxalate, I found the gradations of the negative rather steeper, by which I mean the print was more brilliant with^he amidol than with iron. This I considered a very satisfactory feature, as a flat (over-exposed) negative had pur- posely been chosen to test this point. By slightly diluting the amidol solution, the gradation could oe lessened, but one soon gets to a greyness of colour (which is to be avoided) by adopting this expedient. With a correct exposure, which I have not found to vaiy from that for iron developer, the result.? now compared favourably with others from a ferrous-oxalate developer working in conjunction with an acid clearing bath. But development was too hurried and under little control, which the addition of bromide hardly improved. The results were, however, exceedingly brilliant and very pure and white. Encouraged by the promising nature of the results, I made a series of experiments with the idea of making the developer more permanent in character before use, of rendering its action more deliberate (whilst still speedy), and last, and not least, of giving some control over the development. The result is as follows : — Divided into two solutions, for convenience in preparation and for storage, the acid sulphite and amidol makes a bright and clear solution, without deposit, and which I find keeps well. The colour of the deposit (in the picture) is at least as good as when the solution is prepared with sulphite of soda, I think better, and compares favourably with iron. The bromide does not seem to increase the exposure, and only makes development slow enough to be under reasonable observation and control, whilst it is still quicker than it is with oxalate, which is itself a quick-acting developer. The carbonate of soda solution is to be added quantum suff., and should be used with discretion, but the amount of bromide restrainer removes all tendency to fog or veil, to which defect this developer, however, seems little subject. Amidol Solution, Acid bisulphite of soda 8 grains. Bromide potassium 1 grain. Amidol 8 grains. Water to make 1 ounce. Accelerator. Carbonate soda .^ 48 grains. Water to 1 oimce. For use, add a few minims (four or five) of the carbonate to each otmce of the amidol solution. The completed developer may be used several times, especially if the bulk of the solution be maintained by additions of newly mixed, fresh solution. This is a noteworthy feature of amidol. The general experience with other developers, and for all purposes, is that, for successful and certain working, a de- veloper can only be used once. This is not my present experience with amidol. To sum up, amidol, in my opinion, is the most dan- gerous competitor of the iron developer for bromide work, and is well worth a trial. It prombes to remove the necoasity, and eren the advantages, of an ante-flxing acid clearing bath. By increasing tlie strength of solution, much greater contrast can be obtained upon occasion than has hitherto been possible, and vice versa. Of the com- parative cost, I cannot yet speak. It does not reduce the exposure and it is not a dirty developer. S. Hkbbebt Fby. CALCULATION OF THE ANGLE OF VIEW. [London and ProTincU Photoj^pliic Auocuition.] In the British Journal Photoobaphic Almanac for this year there is to be found, for the first time, a table of natural tangents by- Mr. A. Haddon, by which the photographer may calculate the angle of view included on a given plate by a given lens, or, conversely, the focus of a lens to include a given angle on a given plate. Unfortu- nately, the rules^formulated by the author of the article accompanying the table are incorrect. As they may lead into error those who acce^ them without question, I offer this criticism and correction in the hope that the tanles may thereby be made of value. According to the first rule : for calculating the angle, half the length of the plate must be divided by the focus of the lens ; the nearest natural tangent to the quotient should then be sought in the table, and the arc opposite it, multiplied by two, will give the angle. A B C. D. Pictare plane. £ F. Horizontal line. G. Centre of vision, B H I. Base of cone of raja 60*. By Mr. Haddon's rule :— L. Centre of virion. F M N. Base of cone of rays 60*. H. Cgtiect station point, or focns. O. Incorrect station point, or focns. P K. Difference, inches e^SS abont. Angle G K H =30', 30' x 3 ^ „ GPH=44. «x2 = :60' Error 28 The error is, the direction to take half the length of the plate. To demonstrate this in a simple way, compare the procedure with that of a draughtsman, who wishes to moke a drawing, in perspective, of a room twelve feet wide by ten feet high, to scale of one inch to the foot. In the diagram, E F is the horizontal line, which must be at the height of the spectator's eye — say, four feet above the floor. Suppose the centre of vision removed two feet to the left of the middle of the horizon. Next describe a circle to represent the base of a cone of rays including the picture plane A B C D, no more and no leas. Thia 88 THE BRITISH JOURNAL OF PHOTOGRAPHY. [February 10, 1893 is done hj taking the centre of vision G as centre, and the line to the farthest corner as radius. It is a rule in perspective that the line of ilirection shall be at right angles with the horizontal line, and ter- minate in the centre of vision. Assume the cone of rays to include 60*. The base of this cone is the circle B H I. The draughtsman eouH now determine the exact position of the spectator. From G, at right angles with the horizontal line, draw Q K, the line of direc- tion. By means of a protractor, connect H with K, so that the angle G K H includes 30°. G K is now the principal ray of a cone of 60°, and represents on the plan the distance of the spectator from the pictare plane. This line is seventeen one-third inches long, very nearly. As the picture formed by n rectilinear lens is in true per- spective, and conforms to the same conditions, it can be said that a 12 X 10 plate, with the centre of vision removed two inches to the Mt of the centre of the horizon, at a height of four inches, will include «n angle of 60° at about seventeeen one-third inches focus. Next work the problem by the method of the article in the Almanac. Divide the horizontal line EF in half at L. With L as centre and L F as radius, describe the circle F M N. From L at right angles with F E, draw the line L O. With a protractor connect F with L O at an angle of 30°. The circle F M N is then the base of a cone of rays of 60°, and O is the station point. But the circle FMN|does not include the whole picture, and the point O trans- ferred to the line G K shows a minus distance of about 693 inches. The photographer consequently would have used a lens of about lOf inches instead of 17?, inches focus. Connect P with H and measure the angle. It will be found that from this station point nearly 88° have been included instead of 60°. book on Pictorial Effect in Photography, also warns the reader against the use of the centre of the picture as the centre of vision. The worthlessness of the rule becomes more apparent when we apply it to pictures of equal length, but different height. Take the series 12 x 4, 12x6, 12 x 8, 12 x 10. The rule would give all these different pictures as taken under the same angle, regardless also of the fact that the centre of vision might be different in each case, an assertion which is obviously incorrect. Take a twelve-inch line at ten inches focus. With the centre of vision midway, the angle included is 62°, but, removed four inches to the right or left, it is reduced to less than .57°. A line of given length may, therefore, include more or less angle, according to its position on the picture Jilane, as may be proved by the scale produced. This scale is divided ongitudinally and latitudinally into spaces representing inches. From one corner, as centre, radii are drawn, representing the ninety degrees of a quadrant. The numbers from right to left represent inches focus, and those from top to bottom inches distance from centre of vision to extreme limit of picture, or farthest corner of plate. By means of this scale the angle of view, or focus of lens for a given angle, may be found without calculation for any picture, which method some photographers may prefer. Having demonstrated the error in the rule, it will be seen the following correction must be made. The rule to find the angle of view should be : — Ascertain the position of the centre of vision ; from this measure tlie distance to the farthest corner of the plate, and divide it by the focus. Seek the nearest natural tangent to this number in the table, and read oH the corresponding arc. Twice this arc is the angle required. THe nature of the error will be found in the assumption of a fixed centre of vision, at the centre of the horizontal line, with the horizon as diameter of the base of the cone of rays. In the example given, the centre of vision was removed two inches to the left, therefore the radius L F was from the wrong centre and much too short. Artists rarely u.se the middle of the horizontal line as the centre of vision. They prefer to avoid it, because the centre of a picture is its weakest point This may be proved by examining the pictures in our gal- leries, or, to come nearer home, consult the lecture before this Society by the late Mr. Norman Macbeth, printed in Thb Bbitish JornNAL »B Photogbaphy for January 6, 1888. Mr. H, P. Robinson, in his To find the focus the rule should be : — Divide the angle we wish to include by two, which will give the arc. Find the natural tangent opposite this arc in the table; measure the distance between the centre of vision and the farthest corner of the plate, and divide it by the natural tangent found. The quotient is the focus. One word of caution in conclusion. Should it be necessary to photograph on a plate of given dimensions under a given angle, first ascertain the length of the principal ray, and then select the lens which will give the image at that focus. In most cases this will be difficult, as the lens stock will rarely be found to include one which is suitable. It is preferable to photograph the subject approximately to February 10, 1893] THE BRITISH JOUKNAL OF PHOTOOIUPHY. 89 size, UMng a plate of somewhat larj^er size, and a lens of rather shorter focus, to allow for the necessary adjustment for objects in the fore- nund. I'lace the camera in position to inchide the correct angle for s and subject, and trim the print. 1'hilip Evbeitt. , THE HAND CAMERA. AND ITS USE IN PICTUKH MAKlSTG.* EXPKKIENCES IN CatTLK STAbKIN.l. Or the various kinds of work eminently suitable to the hand camera, I may mention pictures composed of animals — covh, horses, sheep, and so on. U any here have had experience in trying to secure this class of picture, we shall be at one when I say, to obtain a well-composed picture, with the idea (if there is one) fully carried out, is a matter of difhculty when working in the ordinary manner with tripod ; especially is it so it one is ont alone. Cattle have, under such circumstances, a beattli/ desire to see the picture on your ground glass for themselves. My first experience in cattle stalking was my last for some years- Being out on the prowl, seeking what I might devour, photographically, I came across a fine herd of young bullocks in a field, and in my innocence and usual good nature, undertook to immortalise them. Over the fence I went, quickly got into position, and, everything in readiness, focussing done, and dark slide ready for taking its place — but, what on earth had happened ? Everything possessed of four legs was as fuzzy as fuzzy could be, and over it all had to be done again, this time being more trouble- some ;lthe vain things evidently each desiring to obtain a better position for showing themselves off, and were constantly on the move to the front, so much so, that I thought it desirable to go further away, and begin over again. They unanimously agreed to the former part of my pro- gramme, but disagreed in Into with the latter portion, and whether it was they shrewdly guessed I was only a new beginner, and not likely to do them justice or not I never knew, but one thing was certain, they had a preference for my room rather than to my company ^and meant having it, for it was simply from that point a question of going out, or being put ont, of the field. I fancied the former, and they the latter. I went, and how camera first, and then myself, got on the opposite aide of the iron fence I never knew. There was a shortness of time about the whole affair that was bewildering ; but this is certain, on looking round I noticed several of these new-found friends offering their services through the fence in a very energetic fashion. Photography and art were at a sad discount for the rest of that day. I was down in the same part of Yorkshire this last summer, and passing the'same field, turned the tables on my old friends, and got one good cattle picture and another of a more amusing character, when one was trying to stimulate his memory with a good scratch, very likely having heard of my last visit from his great-grandfather ; however, there was no difficulty this time, everything was changed, and the operations over in a ■very few minutes. Then, again, with sheep, no bother after getting stand, &o., ready, and picture arranged and focussed, to find they have had enough of it and are off. Now the other method is to decide on position, quietly walk to within requked distance, just be ready, and when they are kind enough to line up as you desue, off goes the shutter, and so do you ; everybody pleased — they at your departure, and you at the medals already secured in imagination, that is if you go in for such wicked deeds as trying for medals. The Pleasures of Hand-camkra Work. Then, again, it is undoubtedly capable of being used with satisfaction on the sea amongst the shipping, and along the shore for real picture- making. Hardly any subject, whether storm effects, cliff studies, or, in fact, anything you desire to deal with on the coast, comes amiss, when nsing a good rapid plate and a lens such as I deaeiibed ; these and all the odds-and-ends met with can just as well be done with the hand camera as with one used on a tripod, with a heavy balance in its favour on score of convenience in carriage and working. A goodly proportion of land- Bcape work comes well within its scope, and, in fact, as I liave said before, anjrthing requiring an exposure of not more than one second can be got with certainty, and none of the trouble connected with the use of the ordinary camera and its numerous accessories. It would be possible to continue the list of advantages it possesses, and ihe pleasures derived from its use, for a considerable time, but I do not propose doing so, except to say it is a real godsend when ont skyinn, being ready at the instant, and be the changes ever so rapid none need be allowed to escape this friend ; and this is, as I hope to show you, one of • CoBclnded from page 73. the strongest aids to picture-making. If it was of no other nse than that of getting sky negatives, it would be deserving of our careful attention; as it is, you will find it a good friend and faithful servant if you first under- stand it and use it properly and vitli care, not expecting the impossible, or calling upon it to do that which in our present state of advancement is within the province of the camera and tripod and protracted exposure. Bi.iTK Sp>;ctacles a Useful Aid. There is one small but useful aid in outdoor work. You may often have found a scene that carried you away with its beauty, and a plate or more having been carefully exposed and developed, only to find the resulting negative bring disappointment and disgust. Now this has been perhaps a scene full of variety and contrast, but variety and contrast of colour, and this, when reduced to monochrome by photography, has disappeared. Here you will find a pair of blue spectacles of immense use by giving you a better idea of how the scene is apart from its colour, and so often save both your packet and temper ; they are also of use and com- fort in watching a sky effect, with the sun glaring at you. Without them you are quickly blinded, but with them on you can stare away at the sun, moon, and stars without inconvenience, and so see just the effect you are waiting for at the precise moment most suitable for your pur- pose, and thus add one more good sky negative to yoar stock. You will see a few slides kindly lent me by my friend Mr. Bright, of the Camera Club, and I use them to show some of the varied kinds of work to be done with a hand camera. After they have been shown I shall be glad to answer any questions as far as possible, and still more glad to hear the opinions and experiences of members who may have devoted themselves to this branch. We have not at our disposal to-night sufficient time to go into and deal fully with the matters more intimately connected with the making of pictures- -composition, light and shade, and so forth, but I hope to take up this subject again on some future occasion, if you care to devote another night to it. W. Thomas. ELECTKIC LiaHTING AS APPLIED TO PHOTOGE.APHY. An example of the way in which the electric light can be adapted to photographic purposes has recently been brought to our notice. The mstallation was fixed for Messrs. Andre A Co., of Bushey, by Mr. Henry J. Kogers, M.I.M.E., electrical engineer of Watford, and consists of an Elwell Parker dynamo of 105 volts and 28 amperes, driving 1-2000 o.p., and 1-4000 c.p. Brockie-Pell Arc Lamps. The peculiarity of the installa- tion is, however, in the methotf in which the arc lamps are arranged for convenience in focussing the light on the " study." The lamps are hung on brass rollers running on copper rails fixed in grooves in wooden frames, the positive and negative cables being attached to the ends of the copper rails, and the circuit being closed from one rail to the other through the carrying wheels of the lamps. The lamps thus have a travel of about six feet longitudinally without any movement of the cables. The frames on which the lamps are suspended can also be raised and lowered by shifting cotmter balance weights hanging from cords passing over a series of pulleys, and, as the framework upon whioh the lamps hang is also suspended on pulleys running on transverse tee irons, the whole of the lighting apparatus can thus be moved on one side out of the way of the operator. It will be seen from the above description that the lamps can be moved vertically, longitudinally, or transversely ; thus every requisite for successful photography has been attained in this installation. The dynamo is driven by a four h.p. Otto gas engine, witli two fly- wheels, and there arc the usual resistance cottii, switch board, cut-outs, and volt meter. Mr. Rogers is about to fit up an incandescent installation on the same circuit as the arc lamp circuit for lighting Messrs. Andre's studios. NOTES FROM SCOTLAND. Photography .and School Boards. The Edinburgh School Board, which has spared nothing in its desire to render their new schools not only perfect so far as that can be done in the internal arrangements for teaching and matters connected therewith, but in external architectural effect, has erected several of the finest examples of building in that city. They have further commissioned Mr. Aytoun to photograph for exhibition at the Chicago World's Fair exterior views of several of the schools, among them Jorphicen- street and Sciennes (the latter name derived or corrupted from an old Catholic foundation near its site, St. Mary di Sienna, circa 1200 to to 1300 A.D.). There are also interior views in the latter of the workroom, with boys at their joinery work, and girls amusing themselves in their swimming dresses in and around the swimming bath attached to the 90 THE BRITISH JOURNAL OF PHOTOGKAPHi^. [February 10, 1893 Bchool. There are also pen-and-ink drawings of the school furniture- which is of a superior type, by the pupils. The fine bit of architecture by Playfair, of the High School, has also, in spite of its difficult position, been beautifully rendered in several views. These wiU form a part of the Board's contribution to the Fair. That rather conservative body, the Boyal Scottish Academy of Arts, has not thought it beneath its dignity to borrow an idea, and from a photographic source. It will be remembered by those who were privi- leged to see it that the Exhibition of the Edinburgh Photographic Society, 1890-91, was held in the galleries which the Academy is also allowed to occupy, and that the hanging of the pictures and the draping of the walls gave a very fine effect to the general show as a whole. The more august body, the Boyal Academy, has this year in its annual Exhibition departed from the usual maroon-coloured barn or auction-room style of hanging. As one of the dailies puts it, "We have changes in the mode of hanging, in the decorations, and in the arrangement of the galleries," and these are but a reflection of the good taste and example shown them by the organizers of the Edinburgh Photographic Exhibition. A New Depakture. A proposal has been brought before the Edinburgh Photographic Society to change its annual time of appointing Council and office-bearers from the beginning of the session in November to its later meeting in June. This seems so valuable a suggestion that we think it well worthy of con- sideration by that wider body, that photographic public which associates into societies with various designations extends all over this country, we might say the world. The Council and ofBce-bearers are elected at present in November, and, as a third at least of these are ineligible for re-election, a continued and desirable change of officials occurs annually, and before these new mem- bers get into working order a large portion of the early part of each working year is wasted ; they therefore propose that the appointments of those officials should be the last work of the last meeting of the session in June, thus leaving them the whole of the recess to arrange and mature plans for the following year, and also to begin that in October instead of November. This seems to be one of the most sensible proposals we have seen for the business working of photographic societies, which always make of the summer and autumn months a holiday for outdoor work, rest, and recrea- tion. The adoption of it need not disarrange the ordinary terms of the beginning of the session, and of payment of subscriptions and other matters of that nature, for, although it might be better were the two periods simultaneous, yet they are by no means a necessity. As the names of the officials of all such bodies are carefully registered in the various almanacs, annuals, and year-books, those published at the beginning of each year would be certain of being correctly posted up to date. We commend the idea to the consideration of those engaged in the work of carrying on the business of such societies as one likely to be of considerable help to them in their sometimes arduous duties. Determination of Measurements by Photooeaphic Means. In a contemporary an anecdote is related as to the origin of the mode of doing this, and as it seems newly imported, and " Made in Germany," it may be as well to scotch it at once. It is, shortly, that Dr. Stolze says, in a recent number of Photoriraphische NachricJitcn, Dr., or Mr. Meydenbauer, architect, conceived the idea in the summer of 1862, during the restoration of Wetzlar Cathedral, and told him of it at that date. All the world knows that this had been done long before that, and by nobody more exactly or perfectly than by Charles Piazzi Smith, then Professor and Astronomer Koyal for Scotland, in his memorable work at, in, and on the Great Pyramid of Gizeh. Previous to that date, also, the present writer was employed by Mr. David Kinnear, architect, inven- tor of the Kinnear camera, and an accomplished photographer, to photograph to scale, and with measuring rods set in various parts, the Free Church (St. George's) of the late Rev. Dr. Candlish, preparatory to its removal and reconstruction, on an improved design, in Stockbridge, Edinburgh, a mile away from its then site, and where it now stands, an ornament to the locality. Nothing was thought of it more than an ordinary bit of work. AN EXHIBITION OF NEGATIVES. The Birmingham Photographic Society had a very instructive and in- teresting meeting on the evening of Tuesday, the 31st ult., when a non-competitive Exhibition of members' negatives was held. The object of the Exhibition was to place before the general members, and especially the beginners among them, a standard of good work, and it is gratifying to report that, so far as the quality of the work on view is concerned, the Exhibition was eminently a success. Upwards of 100 negatives were shown, the work of sixteen members, and these were displayed to the best advantage on racks running down each side of a long table, a row of lamps being placed down the centre, and the light diffused by the inter- vention of tissue paper. It wonld be no exaggeration to say that there was not a second-rate negative amongst them, but the exhibits of Messrs. E. C. Middleton, E. H. Jaques, J. T. Mousley, J. H. Pickard, WUliam Kooke, and E. Underwood called forth unstinted admiration. Mr. W. _S. Horton also had on view a very fine series of collodion negatives, copies of cele- brated pictures, taken many years ago, which were much admired. Altogether the Society has just cause to congratulate itself upon the success of the Exhibition and the good to the general members which will undoubtedly accrue from it. ■ AMMONIUM PICBATE FOE PREVENTING HALATION. Before the Photographic Society of Japan on December 2, Messrs. W. K. Burton and K. Arito showed the results of a set of experiments with plates stained with picric acid neutralised with ammonia (presumably really picrate of ammonium) to prevent halation. Mr. Burton had, some years ago, tried the effect of staining films with various dyes to pre- vent halation, but had not been very successful. As a rule, if halation were prevented, the plate was very much slowed, or there was great difficulty in getting density. With picric acid this was not so. The sensitiveness was somewhat reduced, but not much ; whilst, so far as density was concerned, the difficulty had, up to the present, been that too great density had been got in every case. The picrate did not seem so much actually to slow the plate as to act as a retarder in development. This necessitated a developer strong in alkali, and, even with very small proportions of pyro, or of eikonogen, the density came up too great Doubtless further experiments would lead to the discovery of a remedy. The next were to be made with plates coated with emulsion with which picric acid (or picrate of ammonium) had been mixed. Both halation and solarisation were completely prevented. Several hundred lantern slides were shown on the screen, and it was decided to hold a lantern evening in Yokohama at an early date. CLEVELAND CAMEEA CLUB EXHIBITION. The first conversazione and exhibition in connexion with this Club was held last week in the Co-operative Hall, Middlesbrough, when some very pretty sets of photographs were exhibited both by amateurs and pro- fessionals. The judging was in the hands of Mr. Frank M. Sutcliffe, and his awards were as follows :— Set of six pictures : 1st prize (silver medal). Dr. Stainthorpe, Saltburn ; 2nd prize (bronze medal), Mr. Jobling, Yarm. Single picture : 1st prize (silver medal), Dr. Stainthorpe, Saltburn; 2nd prize (bronze medal), Philip Bulmer, Chester-le-Street. Lantern slides : 1st prize (silver medal), Mr. Taverner, London ; 2nd prize (bronze medal), Mr. J. W. Huggins, Hexham. The Mayor (Mr. C. Lowthian Bell) opened the exhibition, and a very large and exceptionally fine collection of lantern slides were exhibited by means of the limelight under the management of Dr. Stainthorpe. ©ur Biritotial STaftlr. A Catalogue of Stekeoscopic Views. We have received the catalogue of stereoscopic views issued by Messrs. Underwood & Underwood, of Liverpool, Chicago, &c. It contains particulars, with numerous illustrations, of many thousands of stereoscopic views of the chief places of interest on the habitable globe, together with, in many cases, e,xplanatory notes. To lovers of the stereoscope unable to obtain views ( f distant places this catalogue affords the means of gratifying the most variegated tastes in stereo- scopic views, and is besides admirably got up and printed. Political Calendab. The Meiscnbach Company have sent us a specimen of their improved process of photo-engraving in the form of a Calendar for 1893. The subject, entitled Queen of Flowers, has been engraved from the coloured supplement to the Lady's Pictorial Christmas number, a picture of twenty-one printings, and is a charming and delicate example of monochrome reproduction from paintings and colour work by their " special orthochromatic process." The border consists of over 600 portraits of the members of the present Parliament, and, notwithstanding the minute size of the portraits, each is distinct and clear, and can be at once recognised by those acquainted with the original. The fineness of detail is remarkable, and we agree with the Company that it is questionable whether it would be possible to pro- duce a type printing block giving equal results by any other known method of engraving. We esteem the Calendar as a unique speci- men of process engraving, and both as regards the quality of the reproductions, large and small, and of the successful preservation of the enormous number of likenesses included, we congratulate the Company on a most admirable piece of process work. February 10, 1?93] THE BKITISH JOURNAL OF rilOTOORAPIlY. 01 Aidr-M^;moibk PnATiQra dk I'hotobraphis. By Albert Londe. Paris : J. B. BallK-ro ot I'iU. Thr excellence and variety of M. I^onde's desultory photograpliic writingrs, as well as his official pliotographic position at the I'aris SalpOtriere, is suflicient guarantee that any -work on photography from his pen is sure to be distinguished by carefulness of execution. The handbook under notice treats both theoretically and practically f mwt branches of modem photography, and is profusely illustrated. A chapter devoted to colour-photography includes a detailed de- scription of M. Lippmann's experiments. » ♦ I KECENT PATENTS, APPLICATIONS FOR PATENTrs. Xo. 1972.— "The 'Biunio' Photographic Leus." .'. li. Nkwman.— Dato2 Junuari/ 30, 1893. No. 1991. — "An Improvement in Photographic Lenses, also applicable to Jlicroscope and Lantern Objectives." H. D. T\YWB.—/>cited January 30, 1893. No. 2035.— "Improvements in Photographic Cameras." J. G. Goosey. — Dutcd Janiutri/ 30, 1893. No. 2202. — " Improvements in Photographic Printing by Electric Light and in Apparatus therefor." J. E. A. Gwvnne. — Dated Fehrvarij 1, 1893. No. 2226. — "An Ini)irovement in Photographic Ciniera.s." G. E. Ali.ely, A. E. Allely, and T. E. Asroy.— Dated Febnuiry 1, 1893. No. 2288. — "Improvements in Photographic Caiiier.as and in Apparatus connected therewith, t'. D. McKeli.en. — Dated Febriiayij v., 1893. No. 2328. — "Improvements in Photographic Studio Acces.«ories." 11. L. Morel. — Dated February 2, 1893. SPECIFICATIONS PUBLISHED. 1891. 'Photographic Apparatus." Sleduk. " Magic Lantern Slide-carrier." Reed. 1892. " Magic Lantern Slides." Masoh. " Photographic Cameras." GoTz. " Printing Photographic Plates." HiN&s. — " Pliotographic Dish." Ratnbr. No. 391.—" No. 238L— No. 4668.- No. 4886.- No. 5008.— No. 22,63.3.- ilteettngd of Siotttiit^. ♦ — MEETINGS OF SOCIETIES FOR NEXT WEEK. Pate of Ueetisg. 1 Pebrnary 13.. 13.. 13. 13. 13 13 13 13 U..... 14 U 14 14 14 14 14 .... 14 15 IS 15 15 15 15 15 16 16 16 16.. .. 16 16 16 16 17 17 17 17 17 18 Name of Society. Camera Clnb , Darlington Dnndee Amateur Lantern Society Norfolii and Norwich North Middlesex Putney Richmond Birmingham Photo. Society . Derby Great Britain Hackney Manchester Amateur Newcastle-on-Tyne&N.Counties Paisley Rochester Stockton Brechin Bnry Leytonfctone Manchester Camera Olnb Pbotographio Club Soutbport Southsea Birmingham Photo. Society Camera Club Glossop Dale Greenock Hull London and FroTincial Oldham Oxford Photo. Society Cardiff Croydon Microscopical Holboru LeamiuGfton Maidstone HuU Place of Meeting. Charing Cros.'i-road, W.C. Trevelyau Hotel, Darlington. Asso. Studio, Nethergate, Dundee. 20, Hiinovorsquare. Bell Hotol. Norwich, Jubilee Hou.'ie, Homsey-road, N. Boyi**(ryiiiiiasinm,Charlwood-road. Greyhound Hotel. Club Room. Colonnado Hotel. Smith'H Ri'staarant, Victoria-sl. SO, Great Russell-st. Bloomsbury. 206, Mare-street, Hackney. Lecture Hall, Athcnajum. Contnal Exchaufje Art Gallery. 9, Gauze-»treet, Paisley. Mathematical School, Rochester. Mason's Court, Hi[ said that was a mistake. It was desirable that the ]plane of the field should lie in the focus, but all that was necessary was that the angle should be the jiart of the circle covered. He thought Mr. Haddon's table required correction to the extent that "base" was understood where they must reckon half the diagonal of the plate. It was not necessary that the axis of the lens should be directed to the line of vision. In using a wide-angle lens, the axis should be at right angles to the plate, so that the plane of definition should be in the same plane as the plane of the plate. Mr. EvEHiTT a.sked Mr. Debenham if he would take such a picture as he had drawn in the diagram with a shorter-focus lens than seventeen inches, and obtain an angle of 60" ? Mr. Debenham said that a lens of 30° angle was not required. He would get the same perspective with a lens placed at the same place with less than 60°, angle included. An angle of 48° degrees would do. After further discussion, Mr. Teape remarked that Mr. Debenham liad said that it was not necessary to have a lens that wouM cover more than the part of the circle included by the angle, but he (Mr. Teape) thought that, if the sliding front were used, it was necessary for a lens to cover more. Mr. Debenham agreed that one must have a lens which would cover from opposite the centre of the sliding front to the side of the plate. That was desirable for including the amoimt of picture, but not necessary. Mr. Teape said that a mistake was made in saying angle of view when we wished to know the angle of view; the term sliould be "extreme" or "maximum angle of view." As a matter of fact, every portion of a picture was viewed under a different angle. Jn replying to Mr. Haddon, Mr. Everitt said that gentleman had quoted certain authorities on liis side of the question, and triumphantly said that for twenty-tive years his rule had stood, and now photographers were confronted with a new one. Tlie art of perspective was considerably older than twenty- five years. If those gentlemen who devoted their attention exclusively to books wished to include the largest angle with a lens of a certain description and gave rules, he (Mr. Everitt) could quite understand that they would value the method of Mr. Haddon, and naturally would transfer that method to the calculation of an angle on a plate without noticing that the corners were not covered. Mr. Haddon had tried to minimise the difference in angle made by the sky, or trees, or twigs in the corners of a picture ; but, if such were of no consequence, why not confine your angle to the object of interest, and trim the print down ', By Mr. Haddon's rule there was an error of 28° in the angle and of about 33^', per cent, ia the focus of the lens, according to the example he (Mr. Everitt) had shown. Photography had recently been putting forth claims to be recognised as one of the graphic arts, and they should there- fore adopt the parlance of draughtsmen and artists. Harring:ay Photographic Society.— February 2, The President, Mr. D. Towers, gave a demonstration of Bromide Mnlargiiig, Mr. F. Bennett occupied the chair. — The demonstrator used a restrained ferrous - oxalate developer, with Morgan & Kidd's paper, the result being a perfect enlargement. Three new members were elected, and the Secretary read the rer. John H. Janeway, U.S.A., his subject being S^nne Tlwui/hts am the Chemicul Dirti.j"nent of Dry Plates. (See a' future number.) Dr. Janeway remufked, in oonnexiou witli the reference in his paper to .sound produced by the action of light, that )ie had noticed, while on duty on the western, plains, sounds proceeding from telegraph wires — just after dawn and before sun- rise—which he believed were due to the action of light rays. Mr. James WilsoS sked if most of the fog referred to by Dr. Janeway was not caused by decom- February 10, 1893] THE BRITISH JOURNAL OF PHOTOORAl'lIY. 03 iiosition of the ]>yro or itiaterial used in development, ami whether, if fresh developer hail been usmi at repeated intervals, instead of iidiling more alkali, thLi log would have lieen pro REGENT PATENTS M ll MEETINGS OF SOCIETIES " FORTHCOMING EXHIBITIONS M CORRESPONDENCE » ANSWERS TO CORRESPONDENTS »» THE BRITISH JOURNAL OF PHOTOGRAPHY. No. 1711. Vol. XL.— FEBRUARY 17, 1893. THE EYE AND THE CAMERA. The ever-recurring analogy of the human eye and the photo- graphic camera and lens is always of so much interest that no apology is needed before bringing to our readers' notice recent discoveries in optical science in which the resemblance between the two is shown to bo still more close. In the eye we have four transparent optical media through which the rays pass to form an image on the retina ; in the photographic analogue we have media which equal, exceed, or are less in number, ac- cording to the construction of the lenses. The eye has, first, the cornea ; next the aqueous liumour ; after that the crystal- inelens ; and, finally, the vitreous humour, immediately behind which the image is thrown. In our apparatus, the work of man, we have crown glass or its equivalent ; flint glass, the latter possibly of more kinds than one ; and, finally, in the interior of the camera, atmospheric air, which corresponds to the vitreous humour. The sides of the camera itself corre- spond to the walls of the eyeball. Whether influenced by a knowledge of the construction of the eye or not we cannot say, but the makers of our early cameras gave them black walls, just as tlie eye has. Two most important differences, however, are to be seen in the two cases. In the camera the surface which receives the image is separated from the chief curved refracting media by air, the index of refraction of glass into air being very much greater than from the crystalline lens into the vitreous humour, an entirely different series of refractions taking place in consequence. There is no doubt that if there were practical means of carrying such a system out in photo- graphic work, some remarkable results would be obtained. Tlie second difference to which we would draw attention is one which, if earlier observed, as were the darkened walls, would have led to a better appreciation of a still much-neglected point. We are not aware that attention has been drawn to this remarkable and valuable provision as a still more extended analogue to the " backing" of the sensitive surface with black pigment (over all, except one spot). The retina, which receives the image, is transparent, as is our photographic plate, and reflections which would mar the delicacy of its perceptions are by this backing provided against. It is true that a minute area is not so provided ; but, as the inner surfaces are curved, the effect of the circumjacent non-backed retina upon this central spot may be readily imagined. It is thus seen that a due study of the eye would have provided a skilled inventor with effective modes of treating our photographic instruments, one, at least, of which modes was not adopted for years after the advent of photography. We are now come to a point which will enable ua to more fully understand the most recent aspects from which we are taught to regard the eye. When flare spot was in vestigated, and its cause discovered, no one drew attention to the fact that the eye also had its difficulties to contend with from internal reflections ; but, as a matter of fact, at the beginning of the present centuiy, Purkinjie described four different kinds of these reflections that he had seen him- self, though, of more modern investigators, Helmholtz and others were only able to discern three. These reflections are not the Purkinjie figures described in most works treating of the eye, and caused by shadows from overlying blood-vessels thrown upon the retina ; but are distinct images of such an object as a lighted taper, exactly like what is seen in a photographic lens when held between the eye and a spot of light. These three reflections can be seen if two persons hold a lighted taper between their eyes, and, moving it to and fro, so that the reflections appear to come from the pupil, which, as we need scarcely explain, is not a black substance, but merely a hole — an exact diaphragm in fact — in the iris (hence our "iris diaphragms"). The brightest image is formed from the front surface of the eye, and the other two come from the " lens " and the hindermost medium (the vitreous) respectively. The fourth reflection requires the greatest skill in searching for. It arises at the back surface of the front medium, the cornea, and will be seen by observ- ing the brightest image with a magnifying-glass. When this latter is caused to leave the centre of the pupil, there will he seen, between it and tlie centre of the pupil, another small, pale, clearly marked imago, which makes four reflections. It has always been pointed out that the fewer the reflecting surfaces in a lens the quicker it will be. In a single lens 92 per cent, of useful light is obtained ; but the eye gives 97. The internal reflections into a camera, say, in the case of a single lens, amount to one-sixth per cent., but to the eye to not one-eightieth of that amount ! But at last even this small amount of reflection has been observed in two distinct phases. Tliis makes six reflected images now perceivable in the eye, and a seventh was expected to be visible. It was found in an artificial eye, but not in the living organ ; the amount of available light in the eye swamps this image. In conclusion, we may continue the analogue by pointing out that, as the lens-maker carefully examines in every instru- ment he makes the way the various images of a spot of light behave in different positions of the lens, and so knows whether the components are duly " central," so an examination of the images in the living eye enable the physican to discover whe:i anything is wrong with its interior optical media or surfaces. It is thus seen in this brief survey how much that is valuable in 98 THE BRITISH JOURNAL OF PHOTOGRAPHY. [February 17, 1803 photographic practice is indicated by a study of the eye. Is it too much to anticipate that even yet it may be found to point out further improvements in optical construction or the applica- tion of optical principles in photographic technics 1 PHOTOGRAPHING HORSES. On more than one occasion of late, photographs of horses have been sent us by correspondents, for various purposes, which have seemed to us so unsuccessful in the rendering of the equine subjects, both as likenesses and as technical representations illustrating the principal points of the originals, that wc have thought it opportune to devote a brief article to the subject, in which branch of their profession most photographers at some time or other will probably have found themselves engaged. Without pretending to the possession of any trace of " horsiness " ourselves, we can at least appreciate the cir- cumstance that, as in the portrayal of the human species, something more than haphazard or chance is demanded at the hands of the photographer before a favourable result can be expected. We cannot possibly do better than indicate at once in general terms the character of the equine jhotographs we have recently seen, and which we will take as displaying to a singular degree of perfection the very worst way in which the friend of man should be photographed. The animals have been taken against such backgrounds as stable doors and the sides of houses, and so that only the near fore and hind legs were visible in the photographs, while the animals' heads were droopii?g, the ears turned backwards, the positions betokening list- lessness of demeanour, and vouching so little on behalf of the animals' spirit and character, that we can quite imagine to the eye of an horse expert the photographs conveyed far from a favourable idea. What we here say applies, we have observed, to racehorses, carriage horses, and even to the simple Dobbin of the tradesman's cart. Captain Hayes, a distinguished authority on the horse, and whose photographs of that and other animals, which have been recently shown at the Polytechnic Institution and some of the photographic societies, attest the possession of a very high degree of photographic skill, which we can confirm from personal inspection of them, gives some simple directions for the photographing of horses which may be so useful to photographers that we make no apology for here alluding to them. That gentleman, if we take him aright, recommends that a horse should, where possible, be photographed away from his habitual surroundings, such as his stable, for the reason that when near home his condition is largely influenced by his en- vironment, so that his bearing and attitude are of a degage character, and therefore not entirely favourable to the display of his liest points. Captain Hayes says that when a horse is in a strange place he is all agog with curiosity and alertness and the excitement engendered by novel surroundings, a con- dition which is the most suitable for obtaining an animated portrait of him. In this interested and excited condition the animal's ears are well placed forward, the curvature of his outlines is at its most natural rendering, and possibly the four legs are so placed on the ground as to impart a realistic air to the animal. The horse should be photographed, according to Captain Hayes, against the sky-line in profile— and broadside on. Other authorities, however, unite in recommending the picture to be taken slightly in perspective. Both methods, doubtless, are excellent for securing a likeness, but we should incline to favour that of Captain Hayes, where it is sought to secure an animated picture and to show the dominant points of the animal, although possibly the latter, from the standpoint of picturesqueness as understood by artists, has something to recommend it. In any case, however, it is seldom that a satis- factory picture of a horse taken " end on " can be obtained. We recommend this consideration to the attention of the numerous amateurs who are fond of including sheep and cows in their pictures. Such animals, taken end side on, often have a grotesquely squat appearance. It is, we believe, at times difficult to get a horse to stand so that his four legs are placed in such positions as to show separately in the picture taken broadside on. Too many photo- graphs of horses portray the animals, as it were, standing on two legs only, on account of the photographer having an in- sufficient conception of how the portrait of a horse should be taken, or possibly of a lack of the necessary patience to secure a suitable attitude. Hence, as short exposures as practicable arc to be recommended, a condition of things which, with a stand camera, necessitates a very rapid lens and plate and a quick shutter. Captain Hayes, we believe, works with a twin- lens hand camera. In the foregoing we are alluding less to horses in rapid motion than in the comparative repose of the paddock the field, or the stable-yard, our remarks not being intended to in- clude horses racing or jumping, although there is a certain parallel throughout. Farm subjects including studies of the placid animals usually to be found therein, necessarily should engage special attention on the part of the photographer towards the horses, as well as to the two-legged figures in the picture. Few photographers have the skill of getting a horse to stand as they would wish him to, and therefore the use of a hand camera is all the more to be recommended, having regard to the ease with which subsequent enlargements may be made. As regards the backgrounds, the sky is, of course, less suitable for grey horses than for those with dark coats, as the outlines might not appear so sharp as they really were, and in that case amass of trees, or even the side of a house, offers no objec- tions. Now and again a single horse may be found so tract- able as to allow of an exposure by means of a cap being given, but where several horses are to be included quick shutter exposures are indispensable. The variety of movement in which they indulge can only be appreciated by the photographer who has to wait till they are still before removing the cap from the lens. AMATEURS' BACKGROUNDS AND ACCESSORIES. I. There is probably no point in connexion with jiortraiture to which amateurs, as a rule, give less attention than to the back- ground, although, as every observant individual must agree, nothing contributes in a greater degree to the final effect in the ijicture. It is a pet' theory with many of the class that amateurs' portraits are " so much more natural," because they arc usually taken under more home-like conditions, and without the conventional surroundings of the regular professional studio. But it is possible to take an exaggerated view of the supposed advantages referred to, and by carelessness allow what might otherwise be an artistic portrait to degenerate into the conuuonplace. ^ February 17, 189^] THE BWTISU JODIiNAL OF PHOTOGRAPHY. Reviewing the various styles of portraiture that have pre" vailed since the earliest days of photograjihy, we shall find a vast difference in their general aharacter at different periods. Taki', for instance, the I)i)>,'iierrcotype of forty years ago or more, and wo have to chronicle an almost entire absence of accessories of any kind, the style of picture at that time, and for some years later, consisting chiefly of busts, or at most half-length sitting figures, in which there was little room for the introdiiction of anything in the shape of fdniiture or orna- ment. I?ut with the advent of the carte-ile-nsiti- there came an entire change, and with balustrades, pedestals, bookcases, pianos, and similar accessoriee, solid or sham, together with curtains and painted backgrounds in every jiossible style of subject, the actual portrait frequently had to take a very sub- sidiar}- position in the picture. The next change was in the directioft of more artistic light- ing, and with cabinet and larger portraits came " Rembrandt " and "Salomonesque " effects, and a partial return to the simple style of earlier years. It would be difficult to say what is the "prevailing" fashion at the present day, for while accessories of various kinds, as well as Ecenic backgrounds, are just as much used as formerly in certain classes of portraiture, though perhaps with more artistic taste, we have also a wide choice between the plain vignette or bust and the home portraits and family groupings that have become so fashionable in recent years. It is in the latter direction, indeed, that modern photo- graphic portraiture is surely tending, owing to the ease with which the exposures may now be made in ordinary rooms, or without the necessity that formerly existed for a specially glazed studio. Home portraits, as we usually understand them, are such as are actually taken at the home of the sitter, though there are professional portraitists, both in this country and on the Continent, who make a feature of this style of picture in studios specially fitted for the purpose. Whichever plan may be adopted, however, it is certain that the professional will suit his background and accessories to the immediate require- ments of the case, and not leave the portrait to take its chance amongst incongruous surroundings ; the amateur, on the other hand, is too apt to take things as he finds them, and, for want of a little thought and management, to produce work that were better left undone, when it might almost as easily have been of a totally different character. How often, for instance, do we see home portraits, or those taken in an ordinary room, ■well lighted and posed, and possessing all the characteristics of naturalness, and yet entirely spoilt by the obtrusion of some article of furniture very much out of focus, filling up a portion of the background. Or it may be that the blurred pattern of an elaborate wall paper draws the attention away from the portrait, or the latter is perchance half lost in a mass of total darkness. Again, in the case of outdoor pictures or groups, it is seldom that a due amount of care is taken in arranging the figure or figures so that the surroundings harmonise and form anything worthy of the name of picture. Beyond placing the sitter so that a fair amount of light may fall on him or her, no further care seems to be considered needful, and the backgrounds may be composed of shrulis, foliage, and brickwork in happy confusion. Such a rendering may be natural in one sense, but it lacks the ars celare artevi neces- sary to make it artistic. It is not, of course, everywhere possible, even with the best efforts, to bend the surround- ings to the artistic will, and where such is the case it is. in every sense, preferable ti rolinquiah the attempt, and to substitute a plain and unobtrusive background which will, at least, leave the portrait to stand upon its own merits. We by no means wisli to in the usual manner. Develop with — No. 1. Sulphite of soda (crystals) 3 ounces. Eikonogcn , 1 ounce. Hot water 45 ounces. No. 2. Sal soda 4 ounces. Water 15 „ To develop, take of — No. 1 3 ounces. No. 2 1 ounce. When the negative is almost developed, expose it to daylight, keeping it well covered with developer. In about thirty seconds you will see the change from negative to positive. Wash and fix in the usual manner, and you will have a well-defined positive." We should like to see this experiment duplicated and confirmed, if only to establish the fact of an alkaline developer being a " solvent of metallic silver." To Prevent Silver Stains. — Mr. J. Heygessy, in the St. Louis and Canadian Photographer, who had tried many remedies for preventing silver stains without success, says that one day, being in a hurry to get a few prints from a negative, he noticed silver stains spreading all over it save where the retouching medium had been applied. Ever since then he has rubbed the medium over the entire negative, and baa tried every way to produce silver stains upon re- jected negatives, purposely making the paper damp, but cannot do so Any medium having turpentine for its base answers the purpose. Sunday Work In the States. — Anthony's Bulletin says : " Hereafter Boston photographers are forbidden to work on Sundays. This will be a serious loss to certain of them who do a larger business on this than on any other day. It seems that the law regarding Sunday work has long been in existence, but had practically become a dead letter. All this is to be changed, as the Chief of Police has expressed his intention of strictly forcing this regulation." A. Convertible Camera and Photogrraplx Bxbibltor. A recently patented invention in the United States is a convertible camera and photograph exhibitor, by means of which negatives may be taken and the pictures, after being printed on suitable material, such as sensitised film, to produce transparencies, reinserted into the camera and viewed under transmitted light, in tlie camera, through a lens in the camera case. The device is designed to afford not only a good camera, but also means for magnifying and inspecting the finished photographs, and is preferably made so small as to be convenientl}' carried in the pocket. "As Others See Us."— The editor of the Photo-Beacon (erstwhile the Chicago Beacon), in the course of an appreciative article on " Prints on Rough Paper," remarks : " The so-called im- pressionistic photography was unfortunate in having for its godfather a man steeped in egotism, and whose language was as intemperate as is that of a temperance lectm'er, and consequently both he and it were simply laughed at by all but a very few. As nothing kills so quickly as ridicule, the disciples of the then-called " fuzzy " school had a hard fight to make their way, and not indeed till their self-constituted leader, disgusted at not being appreciated according to his own idea of his merit, turned his back upon photography, did they get anything like a patient hearing." Dr. Emerson will chuckle at reading this, we are sure. We hope to find, when he reads his paper next month st the Great Britain Society, of the council of which he is nowa ni«ai1ier, that he has not turned his back on photography, as the I'kua-Jieaeta has it. American Photogrraphic Societies.— A writer ia ao American journal claims that there are about 1(X) photographic societies in the United States, and the editor of Wilton's Photogrmphie Mayasine (the appearance of whicli in its new dress is exceedingly attractive and quite up to date) interjects, " More than that." Assuming that there are 120, we in Great Britain, with not mucb more than half the population of the States, have between 200. cad 300 societies. ON THE PRODUCTION OF BLACK AND WHITE NllOi- TIVES BY MEANS OF ARTIFICIAL LIGHT. II. In a former article I described a convenient method of using ike Argand burners as a means of lighting the subject, and meatiooed that a very effective set of refiectors were those made of plaster t5. (2) Mathematical Perspective. — Objects become smaller and smaller in appearance, and nearer and nearer together, the farther away they are. Thus streets appear narrower and narrower, and the nouses lower and lower, the more distant they are. Parallel lines of all kinds, such as railway stringers, bridge timbers, etc., converge more and more to a vanishing point (Le Conte). Our judgment in the matters of size of objects, and degree of convergence .of parallel lines, enables us to judge distance with great accuracy and almost without limit. Again, the size of an unknown object is judged by its angular diameter multiplied by its estimated distance. The retinal image of a given object, or the image of that object on a photographic plate, may have the same area covered by a larger object at a greater distance, or a smaller object at a less distance. In vision the estimated size of the object which produces the image will depend upon the distance we imagine the object to be from us. Thus estimates of size and distance are very closely related to each other, and an error in one would involve an error in the other. It is important to note in this connexion that if we mistake the size of a known object, as, for example, a boy for a man, we shall to the same extent misjudge distance. It appears to me that this is the crux of the unsatisfactory images given by wide-angle lenses, or lenses of short focus when a near foreground is included. In viewing photographs taken by such lenses we never do, as a matter of fact, place our eye (or take our point of sight) at such a distance from the photograph that the angular dimensions of a foreground object and another object, distant, it may be, only a few yards further off, shall include the angles which mathematical perspective has rendered them in the photographic image. Take the case of an ordinary interior. The figure of a boy in the foreground would be represented by a much larger image than that of a man at the further side of the room. To look at such a photo- graph from the ordinary distance of vision — say ten to twelve mches — it would convey the impression that this room must be immense as regards its length, that such proportions could possibly be brought about. Our knowledge of the comparative dimensions of the boy and the man is such as to make the treatment of the latter not only disproportionate, but ridiculous. The same argument applies to the unsatisfactory rendering of all architectural subjects in confined situation. \Vere it possible to remove the point of sight, or the camera, further away from the subject in the foreground, one would immediately bring about less disproportion between the sizes of objects in the foreground and more distant points of the subject. We value short-focus lenses on account of their adequate depth of definition through receding planes, but their perspective, when in- cluding near foreground, never looks right! The painter-artist fulfils in his drawing what no lens yet constructed can do ; he takes his point of sight at an imaginary distance, anywhere further back from • where he is forced to stand (if he finds it necessary) — at a distance, in fact, that his knowledge teaches him will practically put all his facts in the picture more nearly in the same place, so that the picture, as a whole, will look right ; as, for instance, the daisy that he is paint- ing in the foreground may really include an angle as large as the lady's foot some distance away, but he does not draw it as it actually is in mathematical perspective dimensions, but in his mind he makes that daisy go away and keep its relative size as a daisy to a human foot. This, from a near point of sight, the camera cannot do. If one were enabled to get far enough away to make such a subject more nearly on one plane, and so look right, it would, as a rule, be so small in size as to be useless. The advantage of " long-focus " lense?, or the more extravagant form, the tele-photographic lens, may now come in where a sufficiently uninterrupted and satisfactory view of any subject can be obtained. Distant groups of cattle, villages^ SDf THE BRITISH JOURNAL OF PHOTOGRAPHY, [February 17, 1893 3ciit»8t«ral structures, &c., can thus be well illustrated, for, although ley »T8 considerably distant, the size of the image is such that they ionot become insignificant. ^Eanuple. — Take an interior 50 feet long, or a group 60 feet deep, ■gr aearest figure 10 feet and furthest 50 feet, and take both figures •• Sleet in height. With a lens of 10-inch focus the dimensions of ft» »e8T and distant figures are 65 and ly inches respectively, or a firapxHiyn of five to one. The same subject, with the lens removed SO feet from the first figure (and, therefore, 90 feet from the furthest), ■maiS giye the dimensions of the figures as IJ and i inches re- aytrtively, or a proportion of only five to three. A longer-focus lens, im^SO inehes, at the greater distance would maintain these more leuoBaMe proportions, and also give the same absolute size, viz., 6^ indies to the fereground figure, as in the first case, but a pro- josfionstely larger image to the distant figure, viz., 4 inches. Now, » *€J»-jiiotographic lens, to give the equivalent of 50 inches, would aHj lequire an ordinary camera extension of from 12 to 15 inches. Aaatber interesting comparison between wide-angle and tele-photo- ^»sj^ic views arises from the fact that we almost invariably look at ^be fcnaej from a greater distance than that of the focus of the lens uttk-trhich it was taken, and at the latter from a less distance than As-i of the corresponding focus of the lens. So that wide-angle views imjr be said to be seen through a magnifying-glass, and tele-photo- aj^i^hic yiews through a magnifying-glass. Outline Fobm and Solid Fobm. ^Ke-oCher aspects of mathematical perspective are those of outKne J^mnaA iolidform. As we have but little to do with the latter in j^jAaf^tiph.j , we had better dispense with this first. In sight we jodp^of it chiefly by binocular perspective, but we also judge of it \fj Ight and shade. Light and shade are admirably rendered by ifaotcf^raphy. Binocular perspective comes into play very much 3»e8e tor near objects than for distant ones, and hence the illusion sf soS^ty produced by the painter is most perfect at a distance, -rnhbie binocular perspective is very small. In all photographic woiJj T reasons already stated, outline form is mos't unsatisfactory in nfertegraphy when near objects are depicted at the sides of a picture taiao-ly wide-angle lenses. We have seen that the drawing given i» aneh) oSjects is in strict accordance with monocular perspective, and this can easily be proved. No doubt many will remember this illostTatioa of Mr. Debenham's vase (British Journal of Photography, tJctober §(^, 1891). Looked at in the ordinary way, it appears to be entirety out of drawing, although, viewed under the necessary fixed ac»>ditions described, the vase can be made to assume its proper shipe. Th& unsatisfaotoriness of such outline form in photography is ff> ^Ipable as to make some subjects impossible in pictorial work. lU^e- »a wdinary interior with, say, an old couple one side of the xooBk and a young couple at the further side. The necessary dis- iariicH} brought about by a wide-angle lens could pay but a poor son^liment to the features of those it depicted. Focal Pbbspkctive. i^ F6cal Perspective. — Monocular focal perspective again will have 1*A % fery small bearing on the subject. We are aware that, if one Bw-le eoDcentrated on some particular near object, that object is dis- tiset, b»t all other objects nearer or further away become dim. This » jeieeptible within much narrower limits than that of binocular TSMDrUnd can only in a minor degree contribute to the question of ^i» JCMistMice of better definition for some part of the picture as MDWured tO' the remainder. The- fact that the exercise of focal perspective is comparatively im- paraeptibfe kas an interesting bearing on photographs, in that it Mcomts lor the more perfect illusion of depth and solidity eflfected iKkcB tley are looked at with only one eye, as the perspective comes aak » j^eat deal more distinctly ; and here we note the great contrast tkat there is in viewing natural scenes with one or both eyes. With ana eye the reverse takes place to viewing the photograph, and we ^s^BJrebotX to fully appreciate distance and solidity. Si •caieluding, gentlemen, I fear I must admit that I have hardly atteied to the title of my paper, and also I am afraid I have had but litUe to say that is new, but I hope the subjects touched upon and ttj^-soggestions I have ventured to make may not be without interest to- 7»o, and may encourage photographers to include among their othej (tudies that of " vision," for I am sure they will find it not i»}y k most interesting one, but also one that I may say is alwolutely aaaenti&l to the production of the best work. T. R, Dallmeybk. THE OPTICAL LA.NTEEN : ITS CONSTEUCTION AND USE. [Before the Brixton and Clapham Camera Club.] Mb. B. E. Pinder, one of the members, read a paper on the Optical Lantern : its Construction and Use. With regard to the lantern itself, he advised his hearers to purchase none but those of English manufacture, as being more solidly constructed and longer lived than foreign lanterns. It is, however, absolutely necessary that the lantern itself should be fitted with the best made English condensers and objectives. With regard to the latter, the most useful focus was eight-inch, the lens being two inches in diameter when four-inch condensers are used. Reliable templates should always be used in order to make the disc exactly con- centric, without which it is impossible to show registering pictures accurately. He advised that the springs in the spring plates should be weakened, and found that washleather pads prevented the clicking of the plates whenever a slide was withdrawn from the stage. He recommended the use of grips to hold the jets firmly when properly centred, and advised purchasers to obtain the best jets they could afford. In using mixed jets, the chamber should be well packed. He himself found that the closely woven gauze, such as is used for cheap tea-strainers, compressed into a conical plug and inserted in the mixing chamber, answered admirably, especially when using the ether light. Having described the use of cylinders, regulators, and dissolvers, he proceeded to give a practical demonstration of the use of the lantern, for which purpose he had brought to the meeting a fine biunial recently constructed for him by Norton, of Russell-square. The lights described and used were the oxy-calcium, the oxy-hydrogen, and the ether lights. He found that the ethoxo light required too much attention to use very often, but advised the passing of the hydrogen, instead of the oxygen, through the saturator. The light produced burned as steadily as the oxy-hydrogen light, but was more brilliant. He pointed out the necessity for keeping the ether in a safe place, preferably a hole in the ground, where accidents could not happen. Having shown how to adjust the lantern with templates, adjustable runners, and stops, he pro- ceeded to give an exhibition of elaborate effects and statuary, the use of the roller curtain being also clearly explained. The President, in thanking Mr. Pinder, said that the paper was made the more interesting by the practical demonstration. The members were surprised to find what a good light could be obtained from common billiard chalk, asbestos, fireclay, or even the bowl of the homely clay pipe, the two latter slightly vitrifying under the intense heat of the ether light. Daring the evening the following resolution was passed : — " That the members of the Brixton and Clapham Camera Club having heard with regret of the death of Mr. William Bedford, one of the judges at their recent Exhibitions, hereby tender to his bereaved family their most sincere sympathy." PHOTOGRAPHY IN ITS RELATION TO THE ART OF PRINTING. [Eiohmond Cuutra Club.] In dealing with our subject I do not think it wUl be out of place to sketch, if only in outline, the history of the sister arts mentioned in our title. I call printing and photography sisters because, in their highest adapta- tion, both are applied in expressing all that is most beautiful in nature, in science, or in art. A photograph will present to us a delightful repre- sentation, and by the help of printing we can not only look npon a pleasing picture, but the words we read can speak to us almost with the force of a living agent. Printing may be described as the art of taking impressions from characters, or figures, on any kind of fabric. What is Peintinq ? As we understand the term "printing" in the present day, it may roughly be divided into letterpress printing, lithography, copper or steel- plate printing, and photographic printing, such as Woodburytype, collo- type, &c. The first of these is from movable letters, metal casts, or blocks either of wood or metal ; the second from drawings on stone ; the third, as the jiescription explains, from subjects engraved on steel or copper ; and the fourth from sensitive gelatinous surfaces acted upon by light, and forming reliefs for printing typographically in specially constructed presses. This is, perhaps, a somewhat technical definition of printing, and a much wider meaning may be given to the term which brings the history of the art back to the very earliest times. It has been said by one writer that printing is the production of a copy by pressure. That is perfectly true with regard to the processes I have already named ; but, to quote from a history of printing published some years ago, "It may also be applied to a seal impressed upon wax to close a letter, or to attest a document ; to coming, i.e., to print upon gold, or silver, or copper, or whatever substance used. It' we give this comprehensive meaning to the word 'printing,' we must recognise the ancient Egyptians as the earliest printers, for they printed inscriptions on bricks, and some of the stamps which they used for the purpose now form p.irt of the antiquarian treasures of the British Museum. February 17, 1803] THE BRITISH JOURNAL OF PHOTOGRAPHS. 106 "The Babylonians also practised the art in this rmln form mnre than 2000 <'.iis ago, and bricks have been fonnd bearing the name of Nebuchadnezzar. This may be called clay printing, and probably was the flmt stei^ in the art. "The next was the use of the seal for making imprcssionx. The Romans used seals at a very early period of their history, and the principle of letter- mess printing, though cruile, was known to them. They seem certainly to h:ive practised the branding of cattle with red hot irons, which, after all is printing in hair, wool, and hide. That they narrowly misled the invention of printing by wooden blocks, which must have led to luovalle types, is evident IVoni the inscriptions on some of the Roman pottery unearthed from time to time. Many of these inscriptions are in raised letters, stampeil upon the clay when soft by means of dyes cut in intaglio. " An accident might have suggested the whole art of printing to an inventive Roman, if one of these inscribed pots had become smoked by a lamp, and in that state had come in contact witii a piece of linen or damp vellum ; the for- tuitous impression thus produced might have given birth to the art. " The invention of money was another step in the art of printing As I have already stated, to stamp on a piece of money was nothing else tlian printing on metal. The method used has not been materially altered in the present day. An engraving of the device to be stamped, or die, as it is called, is cut in a punch, and the punch is forcibly drived against the metal, which is thereby stamped with the device. " As seals were formed with a graver, and money with a die, it is obvious that engraving preceded the primitive method of printing. " The first appearance of printing in a practical shape was when the seal, or other stamp, instead of being forced against a softer substance than itself, was wetted with some liquid of the nature of iuk, and pressed upon another body, so that an image or picture of the stamp was transferred to that other body." It is remarkable that, as the Chinese are generally credited with the first knowledge of the compass, and with the discovery of less useful but delectable things withal, as fireworks and roast pork, so printing was first accomplished in China, by a minister of the State named Foong- taon, in the tenth century. " His plan was to place a page of writing, wliile it w.is wet, upon the face of a smooth piece of wood. The writing made a mark on the wood, just as a letter does when it is turned down upon a piece of blottinz-paoer ; in a word, the writing was impressed or transferred to the woid. Then all that part of the surface of the wood not touched liy the writing was cut awsy, leaving the letters standing out. These were wetted with some kind of ink, paper was then pressed upon them, and an inked copy of the letters was thereby trans- ferred to the paper. This was really and truly the art of printing." The Chinese are remarkable for their stationary character, and I be- lieve it is a fact that they print in much the siime way today as they did 1000 years ago. That movable types are not used may be owing to the nature of the Chinese language, consisting as it does — so, at least, I understand — of separate characters for every separate word, being, in fact, signs of words formed without the use of letters. Printing with wood engravings was effected in 128,!), and playing cards, invented to amuse the mad king, Charles VI., were also printed from blocks about 13.30 ; so that we may presume that the art was transplanted from China to Europe most probably through Marco I'olo's description of it on his return from his travels. Movable Types. The introduction of movable types forms a great stride in the progress of the art of printing. This improvement naturally grew out of block- printing ; yet it was effected somewhat circuitously, and may have been •8 much the result of accident as of design. John Gutenberg was the first person who ever printed with movable types, though his right to the honour of the invention is disputed by the city of Haarlem, which claims the discovery of the art for one of its own citizens, Lawrence Koster. The pretensions of the Dutch, however, in his favour have been extin- I gnished, and Gutenberg is recognised as the inventor of printing in the methods mentioned. In 1449 Gutenberg connected himself with a fellow-townsman, named Faust, in the prosecution of his invention, a connexion which terminated mx years later by a law-suit commenced by Faust for the recovery of monsy advanced. Previous to his quarrel with Faust, Gutenberg had made types of cut metal. The first book ever printed from these v.as the Mazarine Bible, W> called because, after the existence of the edition had been forgotten, a «opy of it was discovered in Cardinal Mazarine's library in Paris. The leaves are printed on one side only, and seven years were spent in pro- ducing it. The first letter in each chapter is painted in by hand. . Peter SchceSer holds the honourable position of being the inventor of cast metal types, without which the art of printing could scarcely have become generally practised. The casting of types at once reduced the cost of their production to less than a hundredth part of what it must have cost to cut them, and thus ensured the eventual spread of the printer's art as an ordinary pro- fession. It is curious to note that it was the practice of the early printers to pretend that their books were manuscript, their object being not simply to conceal the art, but also to obtain the high prices which were given for manuscript books. Books were curiosities because they were few and costly in production. They were deemed as valuable as houses and lands, and were conveyed Irom seller to buyer in the same manner as estates. The inducement held out by the value set on manuscripti was so great, that the early printers never sold their books as printed books if they could avoid it. With one or two exceptions, all the books printed by Gutenberg, Faait, and Sch(ctfer are in the British Museum. InTBOOCCTION of PrINTINO into E.NeLAM). The introduction of the art of printing into England has generally been asisigned to William Caxton. He commenced printing in the year 1474, and found a patron in Mulling, Abbot of Westminster, afterwards Bishop of Hereford, who gave him an old chapel in the Abbey for a printing- office. The spot now forms part of the site of Henry VIl.'s Chapel. The first book printed by Caxton was a Hook of Chess, a title which sufficiently describes the nature of the work. In 1483 there were only four presses in England— Caxton's, at West- minster ; Rood & Hunt's, at Oxford ; De Machlinia's, in London ; and a fourth (name of the printer unknown), at the Benedictine Monastery at St. Albans. Caxton, however, seems to have been the greatest printer of his time. Caxton died about the year 1491, and was succeeded in his business by Wynkyn de Worde and Richard Pynsent. The first, a most accomplished man, accompanied Caxton from the Continent. He introduced the Roman letter into England, and the shape of his types was used for two cen- turies afterwards. The punches and matrices he used in casting his types were in existence as late as 1758. The art of printing spread throughout Britain as the years rolled on. It seems pretty certain that it was not before 1480, at the earliest, that Oxford had its own printers ; while the first printer in Cambridge was John Sibert, whose productions in Latin, Greek, and English bear no earlier date than 1521. It is not necessary to follow the art as it spread gradually throughout the kingdom during the next and following centuries. The Art of Photoorapht. If time permitted us to follow closely the various discoveries connected with the art of photography, I suppose we might go back to the period when the knowledge of the action of light was known to the Egyptians. The discovery of the "camera obscura" (darkened chamber) may, however, serve very well for a starting point. Giambattista della Porta, a Neapolitan, had noticed that external objects were reflected on the wall of a darkened room when the light was admitted througli a small aperture. Following up the inquiry thus opened to him, he contrived the fitting of a lens in a movable box, and in this way produced the instrument which has suggested greater things, and which to the draughtsman and photographer is invaluable. The action of light on chloride of silver was known as early as the sixteenth century, and the phenomenon was studied by early experi- mentalists, whose names will occur to you — Scheele (1777), Genebier (17U0), Ritter and Wallaston (1801). From the results of these investigations experiments were made by Thomas Wedgwood and Humphrey Davy in the Royal Institution, London, which were published in its Journal, 1802. Wedgwood, who was the fourth son of the great potter, may be regarded as the first photographer. He discovered a method of copying paintings on glass by placing beneath a white paper covered with a solution of silver nitrate, and exposing to the action of solar light. He could not, however, fix the images. But in 1814, M. Niiipoe discovered a method of producing, by means of the camera obscura, pictures on metal plates (coated with bitumen), at the same time rendering them permanent. Another name will suggest itself to many — M. Daguerre. He com- menced experiments in 1824, and two years later joined Niupce, and worked with him till the death of the latter in 1833. In 1839, Henry Fox Talbot first published his mode of multiplying photographic impressions by producing a negative photograph (i.e., with the light and shades reversed), and from which any number of positive copies may be obtained. Photo-Zimcoobafht and Photoobaphy on Wood. I think the earliest application of the art of photography to that of printing is the discovery of photo-zincography in the year 1860. This is a process by which photographs are transferred to zinc platei, which may be printed from. It was invented by M. Toowey, and perfected by Sir Henry James, Chief of the Ordnance Survey, and made known at the date already mentioned. Charts, maps, and engravings can be printed in this way at small cost. The adoption of the process by the Ordnance Survey Office has resulted in the saving of expense to the Government. It was not till 18C1 that photography was successfully applied to the transfer of works of art to wood blocks. This was accomplished by Mr. John Leighton in his illustrated edition of the Lyra (lermanica. I have here wood blocks of two subjects showing the image photographed on the wood. The process is of much importance, as the original drawing is preserved, not only for comparison into the finished engraving, but it may be for its artistic value. The drawing also may be of any convenient size, and reduced on wood ; a great consideration when minute objects are to be represented. After the photographing on to the wood is done, the picture is " lined up," if necessary, and more clearly defined by the aid of the pencil and 106 THE BRITISH JOURNAL OF PHOTOGRAPHY. [February 17, 180S Chinese white. This is not always done to aid the engraver, as a skilled engraver prefers to interpret the drawing in his own way without aid, even though the photo on wood be indistinct ; but it is very often im- portant that the subject should be clearly defined, so that the person to whom it is submitted for approval may judge of the correctness and Boitability of the block for his purpose. Photo Blocks. Photography itself, as a science, has advanced very rapidly, even within the last few years. Discoveries are constantly being made of more or less merit, and makers of apparatus are ever ready with some- thing new. But, apart, from this, during the last decade photography has entered very largely into the ordinary commercial undertakings where printing is employed. The art of making blocks with the aid of photography, for the purposes of illustrating forms at the present day, is a flourishing industry. Whilst admitting the beauty of a really good wood engraving, it must be granted that for truthfulness and delicacy nothing can excel a good zinco block for use with letterpress ; and it has this further merit, that the cost is considerably below that of wood engraving. Of coarse, artistic taste and great skill and care in manipulation are required to produce a beautiful illustration, though it is often the case that the choice of picture is with some one who is unacquainted with the requirements of the half-tone process, as it is termed. The beauty of execution in the block is due to the zincographer ; but photographers also have a great deal to learn as to the requirements of the half-tone process, in order to ensure a really good block. This will account for the great differences in the appearances of some blocks in illustrated maga- zines and papers. It is impossible to produce a good block from a negative or a print which does not lend itself to the process ; and it is equally impossible for the printer " to make anything," as the phrase goes, from some blocks that are produced, owing to want of depth and otlier circumstances. Sometimes, however, by force of circumstances, it is really impossible to obtain a good negative or photograph to illustrate a given subject — a fact which will serve to explain, in a degree, the great variety in the qnality of the block produced and printed. There are, as you know, various methods of illustrating the text of any given work, more or less elaborate and more or less expensive in exe- cution. For example, there are lithographs, where many colours are used ; or many coloured prints from a series of wood blocks or zineos carefully registered, i.e., so made that each colour will fall exactly where required. Photography is largely employed for the production of these pictures, or in lithography to ensure accuracy of outline, or for the sake of exactly reproducing stains of age, or usage, or imperfections in old documents, or parchments, or other subjects of antiquity. Direct Photo Processes. Then, again, there are the various and beautiful photographic processes and prints, printed direct on the paper which U to form the leaf of the book ; or a photograph may itself be mounted on to the leaf of the book, to form an " inset " or frontispiece. Of the methods I have already mentioned, I suppose that Collotype, Autotype, or Woodburytype, would be the best forms of illustration for certain subjects for commercial purposes, as they most closely represent actual photographs. Collotype is described to me as biehromatised gelatine spread upon glass and printed beneath a negative, then washed out and used as a printing block in specially constructed presses or machines. The gelatine, I believe, is affected a great deal by the weather, and I am told that there is difficulty in obtaining two impressions alike ; but I have no doubt, in the hands of the experienced collotype printers of the present day, these difficulties will soon be overcome, and it certainly is to their great credit that such good work is turned out in spite of the drawbacks mentioned. Collotype, too, has one distinctive and attractive merit besides beauty, and that is economy in cost of production. But I must not, even if I could do so, dilate farther upon this subject, as by the kindness of one of our members, I believe, we are to be favoured shortly by a demonstration at his works. It was rather ray wish to bring before you this evening examples of the employment of photography in helping the printer to produce an illus- tration at once effective and economical. For our purposes, then, we can divide the term printing into two main divisions, viz. , hthographic and letterpress printmg. Phoio-Lithosraphy. In the first of those, then, photography can be employed to produce a subject or design upon a hthographic stone, realy for printing purposes, in much less tune and with greater faithfulness than can be secured at the hands of an average lithographic draughtsman. Take, for example, a white lace curtain or piece of lace. It is required to show effectively the design of the curtain. This must at least incor- porate a corner— most generally half a curtain is preferred. Now, it is quite obvious that to secure the print which you see (.specimens s/iou'/t), it would take a draughtsmin a long while to complete his work, and it would of necessity be very costly ; so the end is achieved by means of what is called the photo-transfer process. An ordinary wet-plate nega- tive is tiken, and a print obtained on paper coated with biehromatised gelatine. This receives a coating of lithographic transfer ink specially prepared for the purpose. It is next floated in warm water till the Unea are seen as depressions. With the aid of a sponge and water, the soluble portion (or white) is removed, leaving the picture in insoluble gelatine with its coating of transfer ink. It now only requires to be dried and transferred to the stone for printing in the usual way. In printing the illustrations for & catalogue or book, the letterpress, or type portion, can, if necessary, be transferred to stone in much the same way by " transfers " being pulled on transfer paper, and the whole " laid down " and printed at one and the same time. Photo relief etching is a term applied to a picture in relief on metal, ■which can be used like a woodcut in the ordinary printing press. Keproductions of Like Drawings. Photography is very generally employed in the production of line drawings. To produce blocks of these for the purpose of letterpress printing the image must be produced on zinc from a reversed wet-plate negative, giving, of course, a positive upon the zinc, but the reverse way to the drawing. The mechanical tint, or stijjple, is added afterwards if required. The plate is now rolled up, aild slightly warmed before placing in the acid bath or etching solution. It is then well rinsed under the tap, and dried with gentle heat upon a hot plate, and gummed in. After it has been allowed to cool, the gum is removed with a sponge. The plate is again " rolled up," and the surface coated with powdered resin and again subjected to the etching solution. The operation of " rolling up," warming down, dusting with resin to protect the sides of the lines, is repeated until the plate attains sufficient depth. The whole of the resin is then washed off, and the removal of the "steps,' or shoulder, is effected by a series of acid baths in much the same way as the depth is attained, with the exception that the resin is omitted. Collodion for wet-plate photography, which I understand still maintains its stand for copying, was, as most of you are doubtless aware, intro- duced by .\i-cher in 1850. It is desirable, in order to procure the best results, that the subject be drawn larger than is actually required, and bolder in proportion. I have also the pleasure to submit a specimen of another system, interesting on account of its producing somewhat similar results without the aid of photography. Here is a copper plate from which a " transfer " has been taken and transferred to zinc direct. The zinc plate is ready for etching in a similar way to the method just described. I also can show the finished block and impression from it. I have mentioned the production of lace for lithographic printing, but lace may also be illustrated by the aid of zinc blocks such as I have described. In the case of white lace the piece to be photographed is fastened to black material which does not "give off" any light; consequently the result is a beautiful reproduction, with sufficient detail to show the pattern. Black lace is made to adhere to ground glass and photographed against the light, that is, the ground glass is suspended in the line of light between, say, the window and the camera, the lace towards the lens. So much for line drawing?, but by far the more artistic blocks are designed by the term " half-tone blocks." These are specially suitable for portraits, landscapes, and architecture. The processes by which they are produced may be very simple when you know them, but they are not publicly known, and I am sorry I cannot do more than show you a specimen, the start and the finish, as I may call them. Exuraving Processes. I read, however, that some modifications of the methods patented by Mr. Fox Talbot in 1852 and 1858 are understood to be in use. He called his process photoglyphic engraving. Talbot got the image with biehro- matised gelatine. The necessary reticular grain was given to the plate in two ways. By one of these he covered it after development with a fine deposit of resin. It is then ready for the etching solution. By the other method he took fine muslin or netting, and applied it by mechanical pressure to the plate, which covered it with fine cross lines. Goupil, of Paris, has a process which is believed to be worked upon tlie plan of forming a gelatine image, and then eleotrotyping it ; but, as I have said already, the patentees of tlie various processes do not allow information to leak oat if they can help it, and most producers have chemical secrets known only to themselves, though general principles may apply to all the methods. Most of you are familiar with the lettering, as it is called, on the covers of bound books. The designs for these are usually cut in brass, from drawings on paper ; but, since the application of photojraphy, zino • blocks are now being made which bid fair to supersede the older and more expensive brass blocks. Tlie metal for these is rendered extra hard to resist the heat necessary in the process of gold blosking. All process blocks can be duplicated to any extent by electrotyping or stereotyping at a low cost, so that one may readily perceive the advantage to be derived by advertisers wishing the same illustration to appear simultaneously in, say, fifty periodicals or newspapers. The cost of fifty original blocks would, of course, be pra-itically prohibHive. ZixcooR.iPur. The public, then, reap a benefit by the production of the kind of blooka that I have attempted to describe, because attractive books, newspapers, February 17, 1893] THE BUlTISIl JOURNAL OF rUOTOGKAPIIY, 107 and periodicals arc produced at a figure which would be well-nigh ira- posBible if the old system of wood-enuraving were resorted to. Zinco- graphy, in its development, has naturally told unfavourably upon many wood engravers ; but these, again, in many instances, liave linked this department with their original profession, and really, for tirst-olass work, steel engravings and wood blocks of high quality hold their own, though for commercial purposes people will not pay the high jirices demanded for them. But then, again, it is quite impossible to employ photography on some subjects, and a choice has to be made of some other method of illustration. One reason of the popularity of " zincos ".is that they can be worked with the typo, ensuring, of course, a saving in the printing, the whole being done in one operation, instead of two or more, provided, of course, the type and block are to be printed in the same colour. In the illustration of books and newspapers it is, of course, most desirable that the reproduction of the photographs should be made as perfect as possible, and in this connexion, before concluding, I must acknowledge my obligation to Messrs. Swain & Son, of Farringdon-street, not only for valuable aid in the technical parts of my paper, but for the skill and care exercised in producing, at my request, the excellent specimens I have been privileged to submit. I cannot pretend to have exliausted the subject before us, but I trust I have said enough to show you the utility, if I may be allowed the term, of the Photographic art to commercial purposes. The application of the art in the way I have attempted to demonstrate has done very much to raise the tone of publications generally, and to educate the taste of the people who read them. It has also contributed largely to replace the crude and occasionally vulgar illustrations of bygone days, and it enables authors and publishers to put into the hands of readers of even the cheapest literature artistic and truthful representations of persons, current events, and matters of interest generally. J. H. Alabastkb. LANTERN SLIDES BY FEINTING OUT. Befork thQ Putney Photographic Society, on February 6th, Mr. W. E" Woodbury, of the Paget Company, gave a demonstration of making lantern slides by printing out. Mr. Woodbury said he understood that making lantern slides by contact had already been demonstrated before the members earlier in the season ; he would therefore confine his remarks to the manipulation of the new printing-out plates, and to making slides by reduction in the camera, with such apparatus as every photographer already had in his possession, or could readily make for himself. He would also show the method of working the printing-out opals, recently introduced by the Paget Company, which was very similar to that required for their printing- out lantern plates. He said that the treatment of the plates and opals was essentially a daylight process, in many respects similar to that in use for gelatino-chloride or albumenised papers. The first point to which he called attention was that the difference between the coated and nncoated sides was not great ; it should therefore be remembered that the plates and opals were placed in the boxes face to face witli a piece of chemically ptue tissue paper between. If by chance they should become disarranged, the glass side could generally be distinguished by small streaks or patches of the emulsion accidentally left on, and. if these should not be sufficiently obvious, the surfaces mieht be breathed upon slightly, when the glass side would immediately show by the condensa- tion of the breath, the coated side remaining tinaltered. The printing was generally done by daylight, the plates and opals being placed in the frames, and afterwards examined in a subdued light. In this connexion he said it would be obvious that the examination of the rigid glass would ne essarily differ from that of paper, which cjuld be bent back and replaced without difEculty. As regards the lantern plates there was no difficulty, as the emulsion was so transparent that density could readily be judged from the back. When one half of the frame was opened in the usual manner, the opals being too opaque for the image to show through, it was necessary to lift them oS the negatives 80 as to be able to look at their front surfaces, and special means for replacing them in correct register with ease and certainty had to be resorted to. Mr. Woodbury said this could be done in three ways. First, the negative was placed in an ordinary printing frame and wedged £nnly in position, the opal was put in contact on the top, and care taken that it was firmly placed against one side and one end of the frame, of vhich a note should bo made ; with ordinary care the opal could be taken up and replaced correctly without difficulty. Secondly, a piece of cardboard trice the width and of a length equal to a plate one si;:e larger than the negative to be printed from, is folded across the middle, and apertures of tiie proper size for the negative and opal cut out opposite each otiier ; the negative is gummed in one of these openings, the opal in the other, and then folded together face to face, and placed in a suitable printing frame ■with a plain glass in front. For a half-plate negative the cardboard . should be 13 X 8.J inches, which, when folded, would measure 6J x 8J, allowing about an inch margin all round the negative, and would tit in a whole-plate printing frame. The description looks somewhat formidable on paper, but the whole operation was very easily performed, and answered its purpose admirably. It should, of course, be remembered that the same cardboard frame may be used repeatedly. Lantern-slide binding slips are conveniently used for holding the negative and opal in place. The third method consisted in the use of a special printing frame designed by Messrs. Paget, and which they will shortly place on the market at a very moderate cost. Each frame is arranged to take two sizes of negatives ; for instance, half and whole, or quarter and half plates, Ac. Tlie negative is securely clamped in the lower portion by turning a cam, which is locked in any position by means of a screw ; the opal is similarly hold in the upper portion or lid of the frame. The lower portion carries four brass studs fitting accurately into corresponding sockets in the lid ; on being lowered on to the frame the studs enter the sockets, and the two parts are thus always held in proper register with each other. By the use of this frame the last trace of difficulty disap- pears, and the opals and plates may be examined as readily as paper prints. The opals and plates are printed somewhat more deeply than will ultimately be required. A little practical experience will soon enable the operator to judge the correct density. The same rules apply as to silver prints generally. Thin negatives should be printed in a weak light, hard ones in sunlight. Mr. Woodbury stated that good results could be obtained on these plates from negatives with a lack of pluck, which would place them out of court with most of the ordinary rapid brands. It is almost unnecessary to add that this is a great desideratum for those who have developed their negatives with a view to obtaining soft and delicate prints, or who may have failed to get the necessary density when using some of the many new developers. Such weak negatives have generally been disappointing for lantern work, and a plate producing slides which will compare favourably with the prints taken from the same negative will be hailed with delight by many good workers, perhaps more particularly among the growing ranks of those who devote them- selves to stercoscopfc photography. The size of stereoscopic nega- tives is convenient for making slides by contact. Each negative also gives two chances against spots, scratches, and other defects, as a slide may be made either from the right or left half. The prints com- posing the stereogram should, however, be soft, and of as delicate a gradation as possible. This requirement has hitherto to some extent militated against the successful use of stereoscopic negatives for lantern work, as lantern plates generally give the best results with rather plucky negatives inclined to be hard wlien printed in silver. When printed out, the opals and plates are ready for toning. Mr. Woodbury said that any of the usual baths will be found to answer. The Company issue the following formuliE : — Combined Toning and Fixing Bath. No. 1 Stock. Hyposulphite of soda 20 ounces. Alum 5 „ Sulphate of soda (not sulphite) 14 „ Water to 1 gallon. Dissolve the hypo and alum each in about one quart of hot water, mix and then, add sodium sulphite which has already been dissolved, making up to one gallon with remaindc* of water. The mixture should be left for some hours to allow precipitate to settle, when the clear solution may be poured off or filtered, and is then ready for use. It will keep in- definitely. No. 2 Stock. Chloride of gold 15 grains. Acetate of lead 64 „ Distilled water 8 ounces. Dissolve the acetate of lead in the water and add the gold. A heavy precipitate will form, which should be shaken up when any is to be poured out. It redissolves when added to No. 1 Stock. For use mix eight ounces of No. 1 with one ounce of No. 2. When this bath is used the plates and opals should not be washed be/ore toning. Separate Toning Bath, Sulphocyanide of ammonium 30 grains. Chloride of gold 2J grammes. Water 16 ounces. The plates and opals must be very thoroughly washed for at least fifteen minutes in running water to ensure even toning. For deeply printed images Mr. Woodbury recommended the combined, and for correctly or slightly under-printed pictures the separate bath. He also pointed out that in the combined bath toning proceeded very evenly, and could be stopped at any stage, care being taken, if the plate had not been in the bath at least fifteen minutes, that fixation should bo completed in a separate plain hypo bath. Unless very carefully washed, prints would tone unevenly in the separate bath up to a certain point, and it might be found necessary to cany the toning somewhat further than intended. For warm tones, therefore, the combined bath would be preferable, and the separate for the colder shades. He then proceeded to print some lantern plates and opals by means of the Platinotypo Company's oxy-magnesium lamp, the operation being fully performed in a few seconds ; he then toned some of eaiih in the combined and separate baths, the manipulation throughout being of a simple 108 T E BRITISH JOURNAL OF PHOTOGRA.PHY. [February 17, 1893 nature, and such as every photographer is accustomed to when toning silver prints. The results were highly successful, and they, as well as a number of finished lantern plates and opals, with glossy and matt sur- faces, were handed round and greatly admired by the members. Mr. Woodbury then proceeded to make a lantern slide by reduction on the Paget Company's rapid lantern plate ; the negative was half-plate size, and of average density, and of a good colour without yellow tinge. It was placed in a suitable frame, placed at right angles to an ordinary camera, which could be moved longitudinally on a board fitted with guides ; the image was focussed by means of a couple of candles placed behind the negative. The lantern plate was put into the dark slide, and a ground glass placed about two inches behind the negative in order to diSus* the light ; the lens worked at f-10, and twelve inches of magnesium ribbon was burned at a distance of about six inches from the ground glass, being moved about as evenly as possible during burning. The exposure proved to have been correct, and the slide was in every way successful ; elaborate apparatus was therefore unnecessary, the chief point being that the light from the burning ribbon should be screened so as not to enter directly into the lens. ME. H. M. SMITH ON "ENLAEGING." Before forty-three members of the North Middlesex Photographic Society and several visitors, on the 13th inst., Mr. H. M. Smith, of the Eastman Company, gave a demonstration of " Enlarging." He commenced with the subject of large cameras and direct prints versus small cameras and enlargements, and, after discussing the various pros and con« of weight, portability, expense, and excellence of results, said he had come to the conclusion that he would use nothing but small- sized cameras and enlarge. He, in fact, went farther, and said he now used nothing but a hand camera for outdoor work. It w^as the greatest mistake possible to suppose that a hand camera was only suitable for snap-shots; when it could be used on a tripod, as most of those now on the market could, he maintained that work could be done with it in every way equal to that done with the ordinary camera, and he had made many enlargements from such negatives which had raised considerable discussion among able photographers as to whether they were enlarge- ments or direct prints, most people taking them for the latter. He then dealt with the manufacture of bromide paper, explaining the old method of coating by hand, and that now generally practised of coating a roll of paper about a mile long by forty-two inches wide by passing it through a trough containing emulsion, then over iced rollers to cool, whence it was carried to the roof of the building, where it hung in festoons of about thirty feet each to dry. The paper was thus prepared much more perfectly and cheaper than by the old method, as nine miles of such paper could be turned out in twenty-four hours. The paper was packed in dozens, eleven sheets facing one way, and the twelfth the reverse, thus enabhng the user at once to see which was the film side. He also referred to the absence of glaze on the surface, making it very suitable for working on with colours. Passing, then, to the actual enlarging he described the various methods of daylight and artificial light enlarging, but recommended amateurs to stick to daylight, as giving the best and most even results. The best way to find the proper exposure was to make a trial on a small piece of pai^er immediately before exposing on the large sheet, and modifying that according to the result shown by the trial. He was of opinion that the ferrous oxalate developer was still the best for bromide paper, and the formula given with their paper could be relied upon. He then developed in succession three prints of the interior of Salisbury Cathedral, one correctly exposed, the second under-exposed, and the third over-exposed, using the normal developer for each, and showing what the result of under and over-exposure was, at the same time explaining how these errors of exposure could be corrected by strengthening the developer by adding more iron for the under-exposed paper, and weakening it for the over-exposed. Replying to questions, Mr. Smith said he did not recommend magne- sium ribbon as an iUuminant, because one could never tell exactly what condition the ribbon was in, and this would cause considerable irregu- larity in the illumination. The household gas, too, was not suitable, on account of the prolonged exposure required, which would be found some- what troublesome. The relative speed of the Eastman paper was that the " extra-rapid " paper was three times faster than the " permanent." Starch paste or a gelatine mountant was the medium used by the Com- pany for mounting their enlargements, but the latter was not so suitable as the former, on account of the quickness with which the spirit evapo- rated, causing it to dry before the print was in proper contact with the mount. Paper had been kept as long as four or five years after manu- facturing before exposing, and yet was found in perfect condition. He did not recommend toning with uranium for sepia tones, because the deep shadows were liable to bronze, giving anything but a pleasing effect. EOTHEBHAM PHOTOGRAPHIC SOCIETY'S EXHIBITION. Os Tuesday and Wednesday, February 7 and 8, the Rotherham Photo- graphic Society held its fourth annual Exhibition in the St. George's Hall, Compared with previous efforts, a marked improvement was notiQeable in the quality of the members' work displayed, and in the general arrange- ments ; while in the matter of public support accorded the promoters must have reason to feel encouraged. Lady Albreda Fitzwilliam per- formed the opening ceremony, in the presence of an intiuential assembly of townspeople, an appropriate introductory speech being delivered by Dr. Baldwin, the president. Mr. G. W. Chambers, J. P., D.L., moved the vote of thanks to her Ladyship, and the Eev. W. Blazeby, B.A., in seconding the proposition, observed that the present exhibition was even finer than the one held twelve months ago. He was glad the Eotherham Society, in one department, was pursuing a very good course, namely, preserving records of old buildings and old streets which were gradually passing away. He was glad, too, the members were paying some atten- tion to the churches of the district. The Exhibition has many attractive features. Lady Albreda Fitz- william, the Hon. Mabel Fitzwilliam, Miss Crossley (Maltby), and Eev. J. Whitehead, Congo Missionary, and formerly of Eotherham, each sent photographs. The members contributing were Dr. Baldwin (President), Mr. E. Isle Hubbard, Mr G. T. M. Eackstraw, Mr. W. H. Haywood (Vice- President), Mr. J. Leadbetter, (Hon. Treasurer), Mr. H. C. Hemming- way (Hon. Secretary) ; Messrs. W. Firth, W. Mason, W. H. Shephard, A. T. Cocking, J. W. Whittington, J. W. Baker, J. Caseldine, J. Clarke,. J. W. Clements, A. Feirns, and J. Sykes. There had been some attempt at " selection," and the result was appreciated. As to processes, it was apparent that the old style of silver printing had been replaced by the gelatino-chloride papers, and various tones, whether intentional or otherwise, were illustrated, riatinotypes were very few in number, and there was not a single specimen of carbon printing. Numerous gelatino- bromides of good quality found places. The loan collection of prints was extensive and interesting. :Mr. E. Keene, of Derby, sent a number of choice platinotypes ■, Messrs. Elliott & Son, of Barnet, exhibited the " Wave " picture ; the Autotype Company lent a number of reproductions, and the Great Eastern Eailway placed at the disposal of the Society the very beautiful series of Norfolk Broads views. Other friends who rendered help were the Eastman Photographic Materials Company, Limited, Messrs. J. Martin A- Company, and Mr. J. Leadbetter. Each evening there was a lantern display, the " Peak and Dale scenery " slides- of a contemporary being followed by slides prepared by the members. Musical selections were also introduced with much appropriateness. NATIONAL ASS0CI.4.TI0N OF PEOFESSIONAL PHOTOGEAPHEES. The third annual meeting of the National Association of Professional Photographers was held in Manchester on Thursday, February 9, Mr. Thomas Fall (London) in the chair. Mr. Fall brietly reviewed tlie progress of the N.A.P.P. since its com- mencement, and strongly emphasised the necessity of having one repre- sentative of purely professional society. The early experiences of the N.A.P.P. had resembled those of all new associations, and had included great difficulties, but the worst were now past. The Council proposed ta push the social element, and strongly recommended an effort to affiliate with some existing or projected body, preferably in London, by means of which, while holding their own purely professional meetings on a special meeting night, they could also arrange to meet one or more provincial members whenever they might be in London. The proposed New Central Club seemed likely to offer exactly the advantages they wished for ; and they, as a body of 150 representative professionals, could form a very strong and helpful section of any photographic society they joined. The Council's report and suggestions were as follows : — " In presenting this the second annual report, the Council congratulate' the members on the increase of the subscribers from 84 at the first annual meeting to a total of 145. " The Council suggest that a certificate of membership be issued to the members of the N.A.P.P. ; that the members generally be invited to send to the Secretary designs in competition for such certificates, the same to- be reproduced in one of the permanent processes ; and that, after present date, all persons desiring to become members must be duly proposed and elected at the ensuing Council meeting. " Propose that Mr. Fall be requested to act as President for the ensuing. year. " The Council have accepted the resignation of Mr. Eiohards as Hon. Secretary with regret, and desire the members to express their hearty thanks for Mr. Eichards' invaluable assistance to the N.A.P.P. ' ' That Mr. Warwick Brooks, Manchester, be requested to accept the office of Hon. Secretary. " The Council view with satisfaction the proceedings taken to inforitt the public of the facts of the free portrait swindle, and express their thanks to the Editors of Truth, of the Practical Photor/rapher, and the press generally for their assistance in exposing these frauds. " The thanks of the Council are conveyed to the Editor of the Spy^ Manchester, for his fearless exposure of practices discreditable to photo- graphy in Manchester. " Subscribers to Guarantee Funds have been called on for a first half of the amount kindly promised by them. Thirty-three pounds has been paid over for the working funds of the N . A. P. P. by these gentlemen, chiefly members of the Council. February 17, 1C93] TlIE BRITISH JOUIiNAL OF PHOTOGRAPHY. 10 " Up to present time, the expensea of the Council attending meetings in London, IMinburgh, Manchester, and Birmingham liave been borne by the inenibera of tlie Council. " A number of members have not yet paid 1893 subscriptions, and the Council reijuest that the same may be paid as soon as possible. " The Secretary has visited Newcastle, Glasgow, Edinburgh, Hastings, Dover, Eastbourne, and other towns, to advance the interests of the N.A. P. P., without any cost to the funds. " Council record their indebtedness to President (Mr. Fall), Mr. Whit- lock, and to the press." Several members supported the Council's suggestions, which were all carried. It was decided to hold the next annual meeting in Cirmingham. <©ur ©tutorial JTatlc. The Pbofessional Retouohing Knife. It is the belief of Messrs. Percy Lund & Co., who are the publishers of this implement, that it will ultimately become as indispensable to the retoucher as the retouching pencil. As to this we cannot offer an opinion, but we shall endeavour to give such a description of the " knife " as to enable those readers interested in retouching to arrive at a conclusion each for himself. Imagine, then, one of those handy pencils so much in use by retouchers, in which the lead moves loosely in the wooden barrel, subject to being projected at the point, and pinched there by a turn of the nozzle ; but in place of the lead a piece of hardened steel wire is substituted, one end of this being ground to a triangular point, and the other made flat with a bevelled point, as shown in the cut. We have also on our table the Idler (Chatto & Windus), in which we find a well-written sketch of George Grossmith, with numerous illustrations, mainly characteristic portraits by that clever entertainer ; the continuation of " Novel Notes," by .Jerome K. Jerome ; " My First Novel," by Miss Braddon, and many other articles more or less copiously illustrated by process blocks. Great Thoughts (A. AV, Hall) maintains its high position in cheap serial literature. When a portrait of Dr. Phillips Brooks, with a sketch of his life and selections from his writings, were given, who would have imagined that, ere the February issue could have been in the hands of its readers, the talented Bishop should have retired from his terrestial labours? This renders the number doubly interesting. Other portraits are those of Commander Lovett Cameron, R.N., Rev. Hugh Stowell Brown, and W. L. Thomas, art director of the Daily Graphic, with T. Ileath Joyce, its senior editor. These latter accompany an itfteresting account of the paper just named, including that of its photographic I department, where the drawings are converted into the blocks used in its pages. The Picture Magazine (George Newnes, Limited) pre- sents a collection of humorous and other pictures, many of them portraits of well-known writers, and others of scientific interest, col- lated from native and foreign illustrated journals. We have also received the "Results of Meteorological and Magnetical Observations for 1802, at Stoneyhurst College Observatory, and St. Ignatias' College. Malta," compiled by the Rev. W. Sidgreaves, S.J., and Rev. J. Scoles, S.J., from which we learn that the new lif teen- inch refractor telescope to the memory of the late Father Perry is expected to be ready before the end of February. Cataloouks. Rou 4' Co., Ill, New Bond-street, London, W. — This forms a cora- ' prehensive catalogue of si.^ty-four pages, and particularises lenses, chemicals, apparatus, and photographic appliances of various kinds. It . also treats of enlarging apparatus, microscopes, with their multifarious requisites, including object-glasses, for all of which this firm has long ; Iwrne a high reputation. Telescopes, binoculars for field and theatre, i meteorological, surveying, drawing, and nautical instruments, with , other like things, form a compendium fitted to prove extremely (•ttractive to the photographer and man 8treet. Canoubnry Tower, Islington. N. 9, Gauze-street. Paisley. Roy.Lit ^ Sc. InBt.,Terraoe-walks. Bank Chambers, Hargreaves-rtreet. The Assembly Rooms, High-road. Anderton's Hotel. Fleet-street. K.C. The Studio, 15, Cambridge-arcade. Mechanics' Institute, Stockport. Charing Cross-road, W.C. Mechanics' Hall, Halifax. 71, Prospect -street, Hull. Rooms, 15. Dawson-street. Dabllb. Percy-bnildingfl, Eberle-street. Champion Hotel, 15, Alderssute-ct. The Lyceum, Union-street.Oldhaiiu Public Hall,Georgc-atreet,Cro7daa.. '* The Palace," Maidstone. Tenby Hotel, Swansea. Obiswiok School of Art. Ohiawick. 71, Prospect-street, Hull. 110 THE BRITISH JOURNAL OF PHOTOGRAPHY. [February 17, 1893 PHOTOGRAPHIC SOCIETY OF GREAT BRITAIN. Febbuabv 14,— Annual G«neral Meeting,— The President (Captain W. de W. Abney, C.B., F.RS.) in the chair. The Affiuation Schemb. The Hon. Secretary announced that the following societies had that day been admitted to affiliation by the Council :— The Leytonstone, Greenwicli, Southport Social, West Kent Amateur, Brechin, Midland Camera, Hampstead, Birkenhead, Rotherham, and Woolwich. The Annual Report. Tlie Annual Report was then read by the Hon. Secretary, of which the following are extracts : — " During the year ending December 31 last, thirty new members have been elected into the Society, and we have lost sixteen by death, resignation, and other causes. The following table shows the changes iu the number of mem- bers that have taken place :— Honorary Members. Life Members. Ordinary Members. Nnn-resident Members. Totals. On January 1, 1892 ... During 1892, elected „ ili«l „ resigned or lost sight of ... 5 0 0 0 1 - 1 0 S56 28 2 13 14 0 0 0 439 30 3 13 Oa January 1, 1893 ... 5 65 370 13 453 "The Exhibition at the Gallery in Pall Mall was conducted in a rather different manner from those held before, in that the exhibits were classified by the Judges before the Hanging Committee entered upon their duties, and the process of selection was much more rigorous. In round numbers, only about two-thirds of the photographs sent in were accepted for hanging. '■The number of exhibitors whose works were accepted was 202, that is more than we have had since the year 1887. The gradual decrease in the total of members exhibiting is compensated for by the non-members. There were twenty-eight foreign exhibitors, namely, sixteen sending from America, four from Germany and Austria, two from Switzerland, and one each from Australia, the Cape of Good Hope, India, France, China, and Japan. " There were 16(5 lantern slides and forty-five apparatus exhibits. "The Exhibition was open three evenings in each week, and through the courtesy of affiliated and other societies, and of friends, as well as of some of our own members, there was no lack of slides for the lantern shows. An extra evening was as usual devoted to the benefit of the Photographers' Benevolent Association. "The admissions to the Exhibition show an increase of 201. Is. 3d. over last year, but there is a slight decrease on wall space and catalogues. The expemli- ture shows a decrease of 39Z. lis. 5d., and allowing for some advertisements outstanding the loss on the Exhibition will be about 45i., as compared with 90/. last. The Council have arranged with the Council of the Royal Water Colour Society for the next Exhibition, " With regard to general finances, the entrance fees and subscriptions are less this year than last, as only two new members have paid the life subscrip- tion as against six last year. The sum of 221. 19s. lOrf. has been expended on the library, and 3/. 2s. on purchase of photographs. MIL lis. Gd. has been received from the guarantee fund on account of 1891, and as this scarcely balances the account for 1892, it will be necessary to again call upon the fund for the same amount. " Several Committees have been at work during the year, and, as the result of their recommendations, the Council have effected economies in the manage- ment of the Society, and a revised series of ' laws ' have been prepared, which are about to be submitted to the members. Nearly 3000 circulars have been issued to members of various scientific societies and others, setting forth the aim and work of our Society, and inviting them to join us. The immediate pecuniary result of this has not been large, but it has been considerably more than sufficient to defray the cost of the undertaking. The introduction of mineralised methylated spirit has been duly considered. " A specification of the Society's lens standards, as added to and completed during the previous year, has been published, and copies of it can be had by any one who applies for them. "The Council have begun to gather together a permanent collection of repre- sentative photographs, kc, by endeavouring to secure some of the exhibits that have been medalled or possess especial interest. In this they have met with a most hearty and generous response from those upon whom we must depend for success in the matter. "The library has been largely increased during the year. Sixty-six volumes have been presented to the Society, about 108 have been added by purchase under advantageous circumstances, the serials for the year add fifty-two volumes, and besides these a considerable number of unbound pamphlets, fee, have been received. The number of serial publications arranged for by ex- change with our own Journal has been increased from twenty-four to tifty- threc, and it is hoped that in the near future this number will be still further augmented by important additions. " The museum has been enriched by a copy of Fox Talbot's Sun Pictures in Scotlaiul, a set of Daguerreotype apparatus, some calotype negatives, and sundry smaller but valuable items. "The affiliation .scheme which was brought forward in 1891 has been de- veloped, and during tlie year fourteen societies have been received into affilia- tion, so that the present total is thirty. Numerous meetings of deleg.ates have been held, and although much time has been occupied in arranging the pro- cedure, and in discussing the most promising and useful fields for activity, the progress has been satisfactory, taking into consideration the novel character of the movement, its wide scope of action, and the absence of any precedent for guidance. A number of sets of lantern slides are already in circulation, including most of those sent for competition to the Exhibition, and several lectures or papers, with explanatory illustrations or examples, are also avail- able. The programme decided upon for the present session includes a series of lectures on Photogravure, with a demonstration of the practical working of the process. Although the direct advantages arising from the movement liave as yet hardly had time to become apparent, there is a hopeful prospect that it will not only benefit photography,' but will strengthen the Society." The adoption of the report was moved by Mr. T. Sebastian Davis, who took occasion to dwell upon the increased usefulness the Society was likely to have on account of the institution of a library and the appointment of an Hon. Librarian, and expressed a favourable opinion of the affiliation scheme. The motion hav- ing been seconded by Mr. W. England, the report was adopted. The Scrutineers announced that the following gentlemen had been elected Members of the Council for the following year -.—President Captain W. de W. Abney, C.B., F.R.S., D.CL. — Vice-Presidents : Messrs. James Glaisher, F.R.S., Andrew Pringle, J. Spiller, and Sir H. Trueman '^ooA.— Ordinary Members of Council : Messrs. W. Ackland, G. L. Addenbrooke, T. Bolas, F. P. Cembrano, jun., E. Clifton, A, Cowan, T. R. Dallmeyer, T. Sebastian Davis, W. E. Debenham, P. H. Emerson, W. England, T. E. Freshwater, Colonel J. Gale, Mr. F. HoUyer, Dr. G. Lind.say Johnson, Messrs. H. Chapman Jones, Alex. Mackie, J. W. Swan, J. Traill Taylor, Leon Warnerke.- r«a«ottom of a tumbler. He showed a large aperture portrait leas of this nature by Thomas Davison (who had by some been termed the inventor of the comiiound por- trait lens), which, though it stopped a large amount of light, produced most charming pictures. Having noted the important parts which Guiuaiul and Bontemps had jdayed in the production of glass free from strife, he said that in pre-photographic times the uses of lenses in combination for observatory purposes was well known, as well as their property of forming images over a moderately flat field, and he exhibited a specimen of an achromatic lens in use previous to the introduction of Petzval's combination. Alluding to its large size, he said in the olden times they used sensitised sheets of paper of large dimensions, and the lenses were of large diameter and long focus. Lenses of that class necessarily distorted, according to their diameter — the larger the area of the lens the greater the distortion. The orthoscopic leas was intro- duced to cu>-e the distortion of the single lens, but was soon found to have a distortion of the opposite character. "Having indicated the property of this lens of giving a larger image than any other lens of similar focus and discussed its other properties, Mr. Taylor said he regarded that leus as the kns of the future, and described how he had obviated the pincushion distortion which it gave by placing a thick piece of plate glass near to the ground glas.s of the camera. In 1889 he extended the application of the orthoscopic principle by employing as an objective an ordinary opera glass, which was strictly analogous to the orthoscopic lens, a system which had since been adopted by two eminent opticians in the modern tele-photo lens. Apropos of this, he I showed two lenses respectively magnifying and diminishing when examined ] individually, and which when placed in contact formed plain glass incapable j of giving an image ; but when separated, and in proportion to the degree of j separation, they became in effect a combination of long or short focus. Pa.ss-^ I ing on to the next branch of his subject, "Simple Glasses as Iniage-formors," ' he said that numerous fine sharp photograjihs were taken with the despised i plain spectacle glass, which should be of a meniscus form. He passed round | some stereoscopic pictures taken in a hand camera by the aid of such lenses by ^ Mr. Henry Sutton, the sharpness of which he characterised as remarkable, i llie first combination by which distortion was prevented was that of Cnndell, j which was introduced for a totally ditterent purpose. It consisted of a pair Februaiy 17, 1893] THE nUITISIl JOURNAL OF PHOTOQAAPHY. Ill of mciiiscns lenses monnte. Vol. XL.— FEBRUARY 24, 1893. PHOTOGRAPHING STAGE SCENERY. Whenever a new piece is to bo produced at the principal London theatres it is a matter of importance with the coii- ■ductors of the illustrated journals — which have recently in- creased to a large extent — as well as the numerous daily and weekly newspapers that occasionally illustrate their articles with sketches, that arrangements bo made for obtaining illus- trations of the principal scenes, characters, and situations in the piece, so that they may appear almost, if not quite, «imultaneously with the notices of the critics. These illus- trations are sometimes derived from sketches made by artists during the rehearsals, and now and then on the occasion of the premiere ; but modern theatrical managers do not take kindly to the presence, during the rehearsal of a piece, of outsiders, particularly if they are connected with the news- papers, and thus as a rule other means must be found for supplying them with sketches. We believe that in this respect photogi'aphy is called into service. The appearance of highly finished drawings of the scenes and characters of a play in a newspaper within very few hours of the fall of the curtain has possibly often excited admiratiofl for the remarkable readiness and skill of the aitists and engravers ; but all cause for wonderment vanishes if, as is sometimes the ■case, the rough sketches, from which those finished drawings were made, are in the hands of the newspaper artists some days before the production of the play. It is here that photo- graphy steps in. Photographs of the scenes are taken, and prints from the negatives supplied to the artists, who thus obtain tlie most reliable form of sketch from which to work. Photographs of this sort need not, of course, be ex- posed with any degree of nicety. All that is required is a negative that will give a print with sufficient vigour to yield the necessary outlines, and some discrimination in the lights and shades. As regards the figures in the scenes, the fact that the character dresses may not arrive until a late moment, or that it is left to the final rehearsals to arrange the exact situations and groupings, combined with the circumstance that the dresses to be worn in the play aro not worn during the re- hearsals, would seem to occasionally interpose difficulties in obtaining completed photographs of the scenes in ordinary cases ; but we belie^-e that at the principal theatres provision is made for the photographers to have an opportunity of taking the entire scene, as it will appear in tlie public perfonnance, with a view to the convenience and assistance of the artists, at a dress or final rehearsal. Photographs of this description must necessarily be taken under disadvantageous circumstances and with the shortest possible exposiu-e. We believe that a special magnesium Hash-lamp is used, as to the powers of which some idea may be formed from a remark of ]\Ir. Milncr (a gentleman who, We believe, has had much experieuce in this class of work), made at a meeting of the London and Provincial Photographic Asso- ciation a few months back. He stated that, using a lamp of this kind, he had exposed a plate on a scene at the Adelplii Theatre with the lens at f-7,i, and had obtained a fairly well- exposed picture in three seconds, the lamp consuming three or four drachms of magnesium in that time, and the flame being very large. No doubt the ordinary illumination of the audi- torium assists in [such cases in materially diminishing hard results. We remember, some years ago, being in company with a friend who was taking a crowded scene on the stage of a London theatre, the only illumination employed being that of the house at its full. Working luider the most favourable circumstances of rapidity as regards lens and plate, and with, if we remember aright, an exposure of about a minute and a half, tolerably well -exposed negatives were secured. The actors and actresses, of whom there were forty or fifty on the stage, kept remarkably still, and the results were such as to allow of reproduction, although they were not, of course, by any meaas well exposed. Ordinary plates were used. The lighting of stage scenes and characters for effects to be appreciated simply from the auditorium is not always desirable from the photographer's point of view, the relative actinic power of the more or less yellow light from footlights, auditorium, stage, and of the limelight, especially if the latter be concentrated, being such as to operate against a hannonious- ness of lighting in the photographs. In ])hotographs of stage scenes that are intended for reproduction wc are informed that this difficulty is overcome by the collaboration of the photographer with those whose duty it is to attend to the stage lighting, the photographer being then able to obtain his own effects. But in such cases the exposure of the plate must necessarily l)e approximated to correctness, and, as with- out the characters time is immaterial, by the absence of the latter the necessary length of exposure can be given. With a photograph of a scene minus the figures, the actors, we believe, give the photographer special sittings in character, eitlier singly or in groups. These portraits are taken accurately to scale, so as to harmonise with the dimen- sions of the scene itself, and combination negatives are then made of the background and figures. It is in this way, we believe, that some of the most widely circulated photo- mechanical reproductions of scenes from recently produced pl.iTS have been prepared. 114 THE BRITISH JOURNAL OF PH010GKA.PHi'. [February 24, 1893 , AMATEURS' BACKGROUNDS AND ACCESSORIES.* , . , . II. That fairly experienced landscape-workers fall into serious errors when called upon to execute a portrait was impresaeii upon lis a short time ago when we picked up the portrait of a lady executed by an amateur of several years' standing. The portrait was earte-de-visite size, and the liead and portion of l)ust occupied the lower inch or so of the picture— an interior. The face was admirably lighted, and the exposure had been just right, and, so far as that part of the business was con- cerned, we should say it was an excellent portrait. But the background was formed by an ordinary sideboard, of course much out of focus, but just sufficiently sharp to show that the handles of the drawers appeared to be about a foot above the lady's head, showing that the operator — who, by the way, is a fairly tall man— had used the camera stand at the same height he would have done for a landscape, which, of course, necessi- tated the camera being pointed down on to the sitter in such a manner that objects on the same level as her face, but further away, appeared much higher. The general effect was grotesque in the extreme, but the artist was unable to see where the fault lay. In order to avoid such mistakes, we strongly urge the em- ployment of a plain background wherever there is any difficulty with the natural surroundings, either indoors or out. In fact, we should say for indoor work make it a regular practice, for it is so seldom the arrangements of an ordinary room admit of a full-length figure being properly lighted for a short exposure. We are alluding now, of cour.se, to all cases where the source of light is a single window of ordinary size, and which is utilised in conjunction with a reflector. Of course, when there is more than the one window, or one of more than ordinary size, the circumstances may be very greatly altered, and full- length figures, or even groups, may be successfully attempted ; but in the majority of instances it will bo preferable not to attempt more than the bust or half-length, and to use a plain background. Even then the average amateur will often persist in his tendency to do what is not right. There are backgrounds and backgrounds, and we have used ourselves, and seen used by others, a great variety of makeshifts, such as blankets, sheets, table-cloths, and even newspapers. The last, in the hands of a clever and resourceful operator, we once saw do duty in a case of emergency, and it was difficult in the negative to detect any signs of it, so skilfully was it worked. But many an amateur would have succeeded in rendering every letter it contained tolerably legible by bringing it as nearly as possible into the same plane as the sitter ; we have actually seen under such circumstances the pattern of a damask table-cloth almost as perfectly rendered as if that had been the intention, instead of a portrait. In the same way the texture of the blanket, once a favourite makeshift background, can be made painfully prominent in a photograph, especially when used indoors with a strong side light falling upon it. There is little real necessity nowadays for such expedients, unless it really be in a case, of emergency, as proper back- grounds are to be obtained from almost any of the dealers at so low a price that no amateur who does anything at all in portraiture need be without one. If, however, there be any so placed as not to be able to procure a proper background, we should recommend, in preference to any other substitute, a .sheet of unbleached calico in its natural condition. This can • Concluded from page 99. be obtained almost anywhere in widths up to seven or eight feet, which will be quite large enough for any requirements. For indoor work especially, the light colour will be a great advantage, as the amount of light that falls upon the back- ground when placed a foot or two from the window and at right angles to it is small as compared with that that i caches the sitter, and consequently its colour is aiit to be rendered much darker than is desirable. After having secured a satisfactory background, there still remains the necessity for keeping it in proper condition. It is scarcely needful to say that it must be kept perfectly clean and free from stains, but perhaps it may be well to remind some that it is equally necessary to avoid creasing the material, as perhaps nothing so completely betrays a background. In the strong side light of an ordinary room, and to a less extent even in the open air, every smallest wrinkle or crease will be dis- tinctly rendered in the photograph, so that every effort should be made to prevent them. 'J'he best way of effecting this is, of course, to have the calico or other material stretclied permanently on a frame ; but this plan is liable to objection on the ground of the incon- venience of storing so bulky an article when not in use. Another method, however, almost equally effective, so far, at least, as preventing the creases making themselves visible, con- sists in having a light framework made to take to pieces like the portable lantern screens, and, in fact, to stretch the back- ground on this when required in precisely the same manner. It will occupy but little space when not in use, and is easily and rapidly put up when wanted. The only other plan is to keep the background upon a roller, like a map, and to suspend it when in use from suitable supports, with a sufficient weight attached to strain out any creases. Few, we imagine, who have once experienced the difference that a good background makes in a portrait would willingly revert to the slipshod system that prevails in too many quarters, and to those who have not yet made the discovery we offer the advice, to try it. Studio Bulldlngr.- -In response to our querist, "H. L.", in last weeli"s Journal, Mr. VVatraough Webster has promised to give us, shortlj- a paper describing his experience of studio building, though he doubts his being able to put the matter " in a nutshell," as " H. L.,' in a second communication to us, .suggested he might be able to do. The Proposed Now Central Photographic Club.— I We give elsewhere some official details of the proposed new central photographic club, the provisional committee of which contains the , names of several gentlemen whose adhesion to the scheme augurs I well for its success. That a club of the kind is needed in London I may be gathered from the remarks in the report of the Council of the National Association of Professional Photographers, which we printed last week, in which it is stated that such a club would be » desideratum to many of its members. We wish the projected club every success. The Photographic Society's Affiliation Scheme and Xaectures. — We congratulate the Photographic Society of Great Britain, and the forty or more societies affiliated to it, on the large and iuterested audience at the first of the two lectures on " Photogravure" by Mr.Denison.of Leeds, last Friday at Bloomsbury Hall. Mr. Denison's paper and demonstration, if not i ew in sub- stance, was a model of lucidity, and what a paper intended for pboio- irrapher-s inexperienced in the process should be. AVe hope this uiu\ umeut will prove to be the nucleus of a technical photographic institute, as suggested last year by Professor Meldola. February 24, 1893] THE BRITISH JOUKNAL OF PHOTOQilAPHY. lU Test for Tartaric and Citric Adds.— As these two substiiiices, the latter especially, iire of considerable importance in pUotojjraphic technics, a delicate means of discoverinp; their presence wlien suspected will naturally bo of value. M. L. Crismer, in the Hidletin SocU-U Chimique, has recently given a new mode of dning this. If powdered citric acid is mixed with an equal weight of twenty per cent, solution of molybdic acid, and a few drops (ten or fifteen per cent, in bulk) of pure dilute peroxide of hydrogen, and heated for tliree minutes in a water batli, shaking frequently mean- while, a pure yellow colour is produced if no tartaric acid be present. But if there be any of the latter substance, even so small a quantity as '2 per cent., a very distinct blue colour is perceptible. Pure Glycerine.— According to Dr. J. Lewkowitsch, in a paper read at the Leeds Pharmaceutical Congress, pure glycerine is a far rarer substance than is usually supposed. As a matter of fact, a large proportion contains arsenic. This impurity cannot, as usually sup- posed, be removed by distillation ; and indeed, once a sample contains this substance, the learned doctor is unable to point out any practical process for freeing it from the objectionable contamination. Then, again, so-called chemically pure glycerines contain notable quantities of "organic impurities, either fatty acids, &c., or so-called poly- glycerols, under which name I may summarise all those substances having a higher boiling point than glycerine itself.' He gives a table containing results of his examination of eight samples of so-called pure glycerine. They contain from about one-fiftieth to one-tenth per cent, of objectionable matter. »' A Mew Hypo." — According to the Vienna correspondent of the Paris Photographe, the days of sodium hypo as a fixing agent are numbered, ammonium hyposulpliite being about to be introduced for that purpose. The new " hypo " obviates long washing, is a white substance, dissolves rapidly and well in water, forming a colourless solution. At the same degree of concentration as sodium hypo, ammonium hypo, he says, fixes more rapidly than the former, while the time of washing is reduced by one-half. The new bath, however, throws down a deposit after a few hours, but only needs filtration to restore it to its pristine power. To these vague details of the new hypo the same gentleman adds the information tliat, so far, it is only a laboratory product, and costs from eight to ten francs a kilogramme. Six years ago, however, hydroquinone cost 400 francs the kilogramme, now it is only 40. Manufacturers hope soon to supply ammonium hypo at the same price as sodium hypo. A Zilvlng' Negratlve. — The recently issued Pioceedimjs of the Royal Society contain an article by Mr. H. Marshall Ward, F.R.S., on the action of light on a particular form of microscopic life, the Anthra v bacillus, in which the luminous rays are shown to possess a most powerful fermicide property. A series of remarkable experiments are shown, the one possessing most interest being a veritable living negative. Our readers are aware of the methods employed by microscopic experts in the examination of microbes. A plate of gelatine is prepared in a special manner and impregnated with matter known or suspected to contain certain organisms. After a time, the spores or germs multiply and form colonies, which give rise to a change in the gelatine medium, and so render their presence readily observable. Mr. Marsliall Ward prepared one of these cultured plates with anthrax spores, and taking certain ^precautions, indicated iy- pj-evious experiments, against' liqiwfactuHi, of the entire surface, e,\- posed it to sunlight witli amark pver it. In this opaqjie mask opscreen •lie cut out the Jetter E,andexppsed it to sunlight on Cooper's Hillfrom ;,. 9.30 a.m. ofl.Wednesday,,I^oveinber 30,,tiU. ;i.iQ p.m, the s^me day, ■yhea the plate was removed and kept, ia a geptleheat till the follow- MJg Friday, on which day it was examined. . The , sijolight had killed ' .;«very trace otn?rfAc«!.i.- Ayhere it had access, to, and the result was, in Mr. Marshall Ward's words^ ".The, letter U. stood, out sharp and transparent from the faint grey of the rest of the gelatine." It is not in our province to point out the remarkable results this discovery may lead to, but it is well worth placing on record the first example of a gelat:r>.e negative composed of living organic beings. I •• Ziatent ZmaRres.— At the end of Urt ysu we gave our readera a short abstract of a paper by Mr. W. B. Croft on latent non-photo- graphic images, or, as he termeil them, Breath Figures. We agun refer to the subject, indicating as it does a direct bearing on photo- graphic theory and practice, as it has become a topic of interest, and has led to a special correspondence in the pages of our contemporary, Nature. One of Mr. Croft's references was to the image often seen on the inner side of the covering glass of a picture that has been framed and glazed for some years. His explanation is that possibly heat and light have loosened fine paint particles, and these have been drawn up to the glass by the electricity made in rubbing the glass. His final impression is that most of the phenomena cannot be drawn out from the unknown region of molecular agency. One of his inferences is to a blind with embossed letters having left an image on the window near which they lay, though not in contact with the glass. In a further communication a similar effect is described as having been seen by him, as also by another observer, of the words, "coffee-room," set off in the .same remarkable manner. Mr. W. T. Thi.selton Dyer writes (to Nature only) describing an effect similar yet different, that seems to suggest explanations for some hitherto unex- plained photographic abnormal appearances. At Victoria Station is a shallow box with glass sides, into which boards are let down with station names painted in white letters on a blue ground, " InJjeb Ciuclb " being the most frequently used board. One night he observed the box emp.y, but to his astonishment tho words "Innf.b Circle" were to be seen in quite clear letters on a dark ground. The only explana- tion he could think of is one which, in a modified form, might account for the imprinting of the subject of an exposed plate on another ad- jacent unexposed one. It is " (i.) that the light of the lamp had produced some molecular change in the paint coating of tlie notice- board ; (ii.) that this had affected differently the blue and the white paint ; (iii.) that the same cause had set up some different electrical condition of the board or the glass; (iv.) that a bombardment of particles of the blue paint had taken place on to the glass, to which they had adhered; and that (v.) the particles so adhering by dis- persing the light produced the effect of the pale illuminated ground, while the dark spaces occupied by the letters, being relatively clean, stood out dark." ON THINGS m GENER.\L. One of the most amusing discussions that have been reported in these pages for some time past is that upon Mr. Haddon's most useful table on angles of view in this year's Almanac. Mr. Everitt's comment, taken alone as a sort of elementary disquisition on trigono- metrical functions, would be interesting of itself, but, taken as an attack on Mr. Haddon's rule, entirely fails, for a very simple reason. To prove the latter gentleman to be in the wrong, Mr. Everitt takes his general and gives a false particular instance, and on these premisses complacently shows the absurdity of the quoted table. If any one wil take the trouble to refer to Mr. Haddon's paper, he will find its title to be Auyle of View Included in a giueit Plate by a Particular Lens It is to be observed that a plate, and not a negative or view, is re- ferred to, and the concrete example of the abstract principle is a false one. Any unprejudiced reader will take it to be meant, or any one who wishes to know what angle \yill be , covered when using plates of a certain size. Mr. Haddon was not called upon to state that the axis of the lens was assumed to be coincident with a normal from the centre of the plate, any more than thA't! the lens was supposed to be used with its own proper hood and with'its anterior surfaces opposite to the view. Something has to be adsunWd always in a paper for non-mathematical readers, just as Mr. Everitt himself, in his diagrams, assumes that in the supposititious; len«9£, his hypothesis, the hood wa» large enough jiot to in,te»'£ere with..the possible field of view.. I recommend every reader of the Ai^s^i^SAQ to take no notice of the objections passed to the paper, but to net on the plain common-sense indications he will obtain from reading it. T^ere is one precaution he must take, he must take the cap off ihe lens or the angle included will be a negative one; and; further; he must not stand on his head when treating it, or the figures wjll be transposed. While upon optical topics, it may "be pointed out that, in the dis- ussions on tele-photographic lenses, one point seems to have been 110 THE BRITISH JOURNAL OF PHOTOtlRAPHY. [February 2-i, 1893 entirely lost sight of, though affecting the apparent effect of ai-ch - tectural views to an important degree. It ia that, when a large view of a very distant building is taken by a leus of this type, all ordinary linear perspective effects are lost. A wide-angle lens is often accused of giving exaggerated perspective. One of these necessarily narrow- angle instruments gives no perspective at all, at least none that can be perceived with the unaided eye. If we are to take Mr. Dallmeyer's paper with no assumptions or postulates at all, (> la Everitt, we shall tind that we can pick holes in his paper read at the South London Society. He says, quoting Le Conte, " Parallel lines of all kinds, such as railway sleepers, bridge timbers, &c., converge more and more to a vanishing point.'' Of course, it is assumed here that the parallel lines are in a plane at an angle to the picture plane. I can most heartily endorse all that the writer says about the extremely interesting nature of the study of vision, and Le Conte's work is sufficiently popular to be understanded of the people. Ilelmholtz also writes most delightful and popular articles on the subject. His great work on physiological optics, to be had in German or French, is " caviare to the general ; " but in the first volume of his series of popular lectures will be found an article on the eye, so full of informa- tion and non-technical language, that the book would be cheap if bought for that lecture alone. There is an English translation of the set published some years ago by Loncrmans. 'Mi: Alexander Watts suggestion of the earthenware ground utensils for development is very good so far as it goes. " Cosmos " has shown one disadvantage it possesses, but another still more im- portant is the large amount of solution they require. I have tried them for fixing, where, of com-se, the amount of solution is of little consequence. Those in my possession, capable of holding a dozen and a half ])lates, measure 9i x 5 x 7 inches, that is, about 3."S cubic inches, just under one-fifth of a foot; and, as a foot is about six and a quarter gallons, it will be seen that decidedly more than a gallon of solution is required for eighteen plates. Such articles, and the correspondence involved, as those upon valuation of businesses, are of great practical value. Many an amateur decides to take up photography professionally, and, with no data such as those I refer to available, might easily lend himself or get led astray in the estimate of the value of a young business. There is no doubt that the question of goodwill is a very thorny one : often there is no real goodwill, and as often it is non-transferrable. But one aspect of the question should be borne in mind when forming •a judgment. It is that, although there may be no goodwill, the fac't that there is a stand obtainable, and a studio ready to enter, constitute a valuable consideration. Many a man who would like to start a business in a particular neighbourhood finds himself unable to find suitable premises perhaps for years ; cases are not infrequent where goodwill of a particular shop has been bouglit simply to obtain premises and the purchaser starts a business of an entirely opposite character. I cannot but call attention to the letter by operator on this topic, for his data are very misleading. Fifteen shillings a week a piece for printer and reception-room attendant could not obtain nor be expected to obtain efficient workers — it is less than labourer's pay. Then, again, in his figures he estimates 375/. for cabinets at fifteen sliillingS a dozen ; that amounts to five hundred dozen, for which he provides five thousand mounts ! Finally, in a business of the .size assumed, one would think the principal himself could do all the " operator's " work to save that salary. However, from whichever point of view it is looked at, such discussions are of decided benefit. FiiEB Lancb. A NEGLECTED DEVELOPER. It is now about twenty years since, soon after its discovery by Schiitzenberger, that hyposulphurous, or hydrosulphurous acid, as it was called by its discoverer, was first suggested as a possible develop- ing agent; but it was not until early in 1877 that, imder the name of the " hydrosulphite developer,'' it was put forward in a practical form by the late M. Sainman, a civil engineer, of Paris. The hyposulphurous acid of Schiitzenberger must not be confounded ■with the compound previously known under the same name, and which, in combination with sodium, forms the familiar " hypo " of the photographer. Up to the time of Schiitzenberger's discovery, chemists had been in some doubt as to the precise composition of hyposulphur- ous acid, then so called ; its formula was generally written down as ILS^O.,, but for various reasons, which need not here be specified, many chemists regarded it as having the formula H.S.03H.,0, which, simplified, may be written as 2 (ILSO..). The German chemist re ferred to showed, however, tliat his new acid had the formula II.,SO.,, and this set the matter at rest, and it was then recognised that the newer compound was more consistently to be designated " hypo- sulphurous '' acid, while to the older, and hitherto known under that name, the title " thiosulphuric " acid was given. Schiitzenberger's acid is formed by the deoxidation, by means of metallic zinc, of liquid sulphurous acid, while the older compound is formed by its sulphuration. The following formula show the precise relations of the three acids to one another ; — Hyposulphurous acid = H^ S O; Sulphurous acid = Ho S O3 Thiosulphuric acid = H.j So 0^ The first-named is formed by acting on liquid, or ratlier aqueous sulphuric acid with metallic zinc, which, in dissolving, abstracts one atom of oxygen, forming a yellow liquid possessing much greater decolourising and reducing power than sulphurous acid itself. It is, however, a very unstable preparation, and a preferable way to utilise its reducing action is in the form of its sodium salt. This, in conjunction with pyro, was, in fact, the hydrosulphite developer of -M. Samman. A concentrated solution of sodium bisulphite is poured mto a flask or bottle containing granulated zinc or zinc clippings, and allowed to stand for half an hour. The zinc dissolves, giving rise to the new acid, and the solution then contains, in addition to sodium hyposulphite (not thiosulphate), zinc-sodium sulphite, the former of which is really the active agent. This compound solution, mixed in equal proportions with a four-grain solution of pyro, constituted the developing solution which was remarkable for the regularity, beauty, and cleanness of its action. At the time of its introduction gelatine plates were practicallv un« known, and the early experiments were made with collodion dry plates. With these it was found that a better though less energetic action was attained if, instead of the bisulphite, neutral sodium sulphite was employed, or the former salt neutraUsed, or partly so, with sodium carbonate. Later on M. Samman modified his formula, and in the Almanac for, 1878 gives one in which the sulphite and bisulphite are combined, and instructions given to neutralise the free acid of the latter— in other words, to convert it into sulphite. It may be added that a solution of ordinary hypo, treated in the same manner with zinc, exhibits developmg power, but, as might be expected, its fixing action is both more energetic and more rapid. It should be noted here that, although the solution formed by the action of zinc upon the neutral sulphite possesses devoloping power.-^ when mixed with pyro which the plain sulphite does not, it contains no zinc in solution, as may be proved by testing it with sulphide of ammonium. Its developing action is, however, much less energetic than when the bisulphite of soda is used, and was at first supposed tu be due to alkalinity of the sulphite ; but such is not the case, as it may be shghtly acidified after decanting from the zinc without losing it» power. To acidify the sulphite before pouring on to the metal would be equivalent to using a small proportion of bisulphite. The solution, as has been already stated, attains its full energy after half an hour's contact with the zinc, when, if decanted, it commences at once to lose its newly derived power, reverting to the state of sodium bisulphite, the zinc being thrown down as a white powder. This change occurs with less rapidity after the pyro has been added, owing, no doubt, to the absor^jtion of oxygen by the pyro instead of by the hyposulphite. In fact, the pyro and hviiosulphite solution re- mains clear, and without deposit, for many hours. This peculiarity WM noted in these pages at the time, but it remained for the late Mr. Herbert Berkeley, some years later, to apply the alkaline sulphites for the purpose of keeping the developing solution clear and preventing discolouration of the gelatine film. As has been said, the early application of this developer was in connexion with dry-collodion plates, for which it proved most February 24, 1893] THE BKITISH JOURNAL OF PHOTOGRAJHy. 117 suitable. The character of the imape was" entirely different from that, produced with the ordinary alkaline pyro, partaking more of the pure metallic appearance of the wet plate. This characteristic rendered it especially suitable for transparency work, and even now without any modification it can b(f heartily recommended to the users of collodion emulsion. It in extremely easy of preparation, all that is required being a wide-mouthed bottle throe parts filled with scraps of zinc, preferably in the form known as " granulated," granulated zinc being obtainable for a few pence a pound at any chemist's. Into this bottle a strong solution of bisulphite of soda — 2(K) grains to the ounce of boiling water, allowed to cool after solution — is poured, and simply allowed to .stand for half an hour or so, when it is ready to mix with the pyro solution. When done with, the solution should be poured off the zinc into a separate bottle and well corked, and in a few hours the zinc it contains will be precipitated, and the solution will have returned to much its original state, and may be used again. The zinc bottle should be rinsed out vnth clean water, ready for use when wanted again. Metabisulphite of potash may also be used, and if found too energetic, tliat is to say, if it causes fog, a little carbonate of soda may be added until the smell of free sulphurous acid is greatly reduced. It may be noted that this developer does not owe its power to alkalinity, as it is more energetic when the sulphurous acid is used in the free state. But, turning to gelatine plates, unfortunately the hydrosulphite developer does not specially recommend itself, at least in its oiiginal form. It is with the intention of making the cause of this clear that I have dwelt at such length on the chemistry of this curious com- pound, which, as I have shown, in the course of oxidation, deposits an insoluble basic salt of zinc. In conjunction with collodion plates this mattered little if it occurred at all, as the deposit formed only on the surface of the film, and was easily removed by washing or by other means. Not so with gelatine, however, for apparently by some special attraction exerted by the gelatine not onlj' does this precipi- tation occur to a much greater degree, but the precipitate is formed in the pores of the gelatine as well as on the surface. Fi-om the latter it is easily removed by washing and friction if necessary, but from the body of the film it is not so easy to dislodge it, and the consequence is an unpleasant veil of a pinkish white shade that especially unfits the solution for transparency work, if not indeed for negatives. W. B. Bolton. (To he concluded.) RETOUCHINO AND VARNISHES. __ As a retoucher of many years' experience, and having — no doubt as many others have done — occasionally h&d failures, which 1 invariably find teach us far more than our successes, and, having overcome them, I think that I may venture to point out to less experienced " knights of the pencil " how they may succeed in varnishing a retouched negative without losing so much as a single stroke of their carefully placed wok. Pardon the digression, but I venture to think that, if the whole of the work of some of the " retouchers " of the present day came off with the varnish, the negatives would yield much more satisfactory prints, both as regards likeness and artistic effect. To begin at the beginning, let us take the medium. I have tried many makes, and have teen successful with them all. Of course I have my favourites, but only so far as regards the tooth, not because I find one comes off with the varnish more than another. I do not recommend retouchers to make their own medium, as it is not worth bothering with. A shilling or eighteenpenny bottle will do some hundreds of negatives if it is not wished for it to come off again with the varnish. For those who may like to make their own, as I know there are many who will not buy anything they can possibly make, I have found nothing better than common resin dissolved in common turpentine. I have used such a mixture for years, and found it work splendidly. I should simply get a lump of resin, about the size of a walnut, put it in an ordinary one-pound jam pot, about half-filled with turpentine, and stand it on the hob, not too near the fire. When dissolved it should look something like strong ale, and when carefully decanted into a bottle it is ready for use. Personally, for some time past I have naed the Autotype Company's medium. Do not leave the cork out of your medium bottle for long, as, if you do, you will soon have only a nasty sticky mess left. I do not like cotton wool for placing it on the negative, as it so often leaves it messy, with little pieces of the wool sticking to it. You are also apt to leave on too much, which, if you do, you may reckon upon a good part coming off again, and the retouching with it when varnishing. I find the best plan is to keep an old pocket handkerchief for the purpose, stretch it tightly over the end of your forefinger, then tip up your bottle of medium so that it moistens the cork, and with the cork moisten the handkerchief on the end of your finger, then rub it icell on the part of the negative to be retouched. If it is a large head, you may require to give two dabs on the finger with the cork, but one is generally sufficient ; but be sure you do not leave on too much. Then you may commence retouching almost at once, or you may leave it for a few hours, as convenient. Now, as to the varnish and varnishing. I may also say that I have worked with many different varnishes, as a retoucher must necessarily do la going from berth to berth, and some employers are very obstinate and think the varnish (or anything else) that was used by an old assistant must do for the new, especially if it happens to be a little cheaper than what the new man recommends. The varnish I generally use when I have my own way is the ordinary " white hard," to be obtained at any oil and colour shop, thinned down with methylated spirit and filtered. In a future article I may describe a very useful varnishing pot that I have in use. Do not use the varnish thick, as it takes longer to set hard, and is likely to become " tackey " in hot weather, when the prints would leave marks upon its surface, and dust be more likely to adhere to it. Although I prefer the " whitehard " varnish, most of the photo- gi'aphic varnishes in the market are good, and 1 have not yet come across one that would shift the pencilling if properly treated. Some few years ago I had just commenced work in a new berth, and had varnished about half a dozen negatives before leaving in the evening ; my surprise may be imagined, on looking through them the next morning before sending them down to the printers, to find that the retouching was scattered all over the plates instead of on the face, &c., where I had placed it. I showed them to a lady retoucher sitting at a desk next to mine, and asked her if she could account for it in any way ; of course, she laughed at the " new man,'' and told me that the emulsion had been thoroughly " cooked " long before it came into our hands, and, if I would be satisfied with only slightly warming it up, I should find matters all right. I think that girl had got to the bottom of moved retouching. I tried her plan, viz., only slightly warm the plate, then varnish, being careful not to pour the varnish on the retouched parts, stand the plate in a rack to set for a few minutes while some more are being varnished, then commence with the first and dry them off by thoroughly warming them. I was never troubled any more ; that was the worst case 1 ever met with, and I think that the varnish had a good deal to do with it; it was a home-made varnish entirely. The principal thought it perfection, made it himself, and kept the ingredients a secret, which I think was a blessing to photographers generally. I have met at various times with slight cases of moving, but have always traced it to the medium being too thick on the plate, or else the plate being made too hot before varnishing, generally the latter. In some firms all the retouching is done upon the varnish, and in quick trades of the middle class it is perhaps best to do so, as I have found that more work can bo got through in that way, the medium upon the varnish giving a better tooth f or the pencil, and the negatives can be varnished as soon as they are dry by a lad, and so be ready for the printer almost as soon as retouched. Now I have found that it is the medium upon the varnish which rubs off (and, of course, the retouching with it) with the constant dusting, &c., so that if the negative is retouched before varnishing, and one wishes to do only a little more after, it is best to dispense with the medium altogether, the varnish itself generally giving enough tooth : but, if the whole, or a great part of the work, is done upon the varnish, medium is necessary ; to protect which in the quickest way is to thnrougMy warm the plate, when it will be found that the medium and retouch- iug have sunk into the varnish and is quite safe. A word as to collodion. If you value your negatives, never allow even a single silver print to be taken from them in this damp climate of ours without giving them first a coat of something damp- proof. If you don't like varnish, give them a coat of enamel collodion: or, what is better, both, as, if you coat first with collodion, and, when that is dry, give a coat of varnish, you will have the best waterproof coating known. If you don't like coating the plate with anything, then have a sheet of talc between the plate and print. But collodion has another 118:, THE BRITISH JOUKNAL OF PHOTOGRAPHY. [February 24, 1898 use. There is sometimes a dark piece of drapery you would like removed, a lady's waist mayW too thick and require some off on the shadow side, or some other dark object you would like taken away, and yet you cannot get on enough pencil to do so, even by working under and over the varnish. Now, if you will use both collodion and varnish, and work on each with a little medium, you may go on in- definitely, using each alternately until the desired effect is produced, and, if both are used thin, the thickness of half a dozen coats is inappreciable. Should the collodion at any time take a slightly opalescent appearance, it will entirely disappear with the succeeding coat of varnish. Haynks Wklch. DETERMINATION OF PLATE SPEEDS. Mb. Williams has not seen fit to avail himself of Messrs. Marion & Co.'s invitation to acquaint himself practically with our method of speed determination, nor to accept our offer to submit his negatives to us for measurement; and, as we have neither time nor inclination to enter into a prolonged discussion with him, we must leave him to discover for himself the faDacy of deciding percentage differences in speed by the ocular comparison of negatives. We should, however, like to say a few words more before, as far as we are concerned, the matter drops. The system of speed determination which we have freely given to the world is, we believe, destined eventually to be generally adopted ; in the meantime we can well afford to look on with unconcern while people, who either cannot or will not study the principles and theoretical considerations upon which the system is based, set them- selves ruthlessly to destroy what we have taken years to build up. We should be the last to claim that the working details of the system are incapable of improvement ; but, while we warmly acknow- ledge the efforts of Mr. Cowan and Mr. Cadett to work the system with accuracy and efficiency, we cannot take any responsibility upon ourselves should errors occasionally arise. The adoption of the check plate, on the initiative of Mr. Oowan, is a proof of the anxiety of those gentlemen to take every possible precaution to prevent error. Mr. Williams' repeated assertion, that he can detect by ocular inspection a difference of ten per cent, in two exposures, convinces us that he can never have devoted any attention to the law which is the foundation of our system, and which is graphically expressed by what we term the " characteristic curve." If he were to plot the character- istic curve of a plate, and then consider the effect upon it of a differ- ence of ten per cent, in the exposure, he would easily convince himself of the utter futility of expecting to find any ocular evidence of such differences in two negatives. Anart from this, Mr. Williams has probably never realised that, in the case of two plates of identical speed but having different characteristic curves, it is absolutely impossible to produce two identical negatives ; and this fact, unrecognised by Mr. Williams, has led him to conclusions which any one acquainted with the charac- teristic curve would at once have seen to be fallacious. Nor has it probably, on the other hand, occurred to Mr. Williams that two negatives, on two similar plates, may have identical printing values, and yet be enormously different when examined either by the eyfe or by measurement. This is only another way of saying that, in a thickly coated plate, having an extended period of correct representa- tion, there is considerable latitude of exposure. These are facts which may appear to be paradoxical to Mr. Williams, but for the explana- tion of which we can only refer Tlim to our papers. We have recently felt that we, perhaps, made a mistake in adopting, for our speed scale the numbers which we did, and that speeds now expressed as 10, 20, 30, for example, would have been better expressed riiS .1,2, 8. The public seem to estimate these numbers far more by their differences than by theirratios, and have so acquired an exag- gerated idea of t!heir influence Upon the exposure. AVhetherthe speed of a' plate is, in practice, ninety Or one hundred, matters absolutely BOthiftg. ' ■■' It is somewhat amnsing to -find 'how -photographers, who have existed- forr go many^ years without -any system offepeed determination wbatiever, ail at OnctJ demand such hairbreadth distinctions. - We suppose k --will -be some time before they- learn to appreciate, the d«i^ee of exactitude Vphich it is either possible or necessary to Ve^li> W«i;*re iglad to say, .ha.weverK thatit is possible, by our method, to jft.iin8teithja.#peed of . a plafe iwith considerably greater precision than iS,actn»,ll.v, required iivpractic^ ; hut tlii9 f apt will not be brought.tpi^e to .jilr, Ayilljams i^ncl photographers generally till they turn'tlieir alteiitibn to the law which governs the action of light upon' the sensitive plate. If, when Mr. Williams has studied our theory of the action of light, he succeeds in disproving it, we shall feel compelled to pay more serious attention to him than we do at present ; but, till then, we prefer to accept as true a theory which is in such complete accord with photographic phenomena generally, and in opposition to which he has not advanced one particle of evidence. W'e hope we may have said enough to lead Mr. Williams to consider whether, after all, our method of speed determination may not stand upon firmer ground than he at present wots of, F. Huhteb, V, C. DniFrrELD, IMITATION PHOTO-ENGRAVINGS. I WAS glad to notice in the last issue of the Jo0bnal that you make mention of some " grating photographs " produced by Mr. John Robertson, of Dundee, as this is a style of picture that I have myself done a good deal with during the last two years or more since I first got the idea from your pages. The results, when properly executed, are exceedingly attractive — -far more so, I think, than actual screen pictures, as the gradation is far softer and more natural than that produced from an inked plate, and I am sure more photogi-aphers would adopt the novelty if it were not for the difficulties involved. It was a long time before I could produce anything that was at all presentable, although I followed as closely as possible the instructions given for preparing the grained screen, as well as its combination with the photograph. To any one taking up the thing for the first time, the production of the grained surface would appear, from the directions, to be the simplest operation in the world, the chief difficulty being, apparently, to select the kind of grain that will look best. But, when he comes to tiy it, it will be found anything but the easy job imagined. It is not only that the task of obtaining an even grain, of whatever kind it may be, is far more difficult than it seems, but, having obtained the necessary degree of uniformity, ihe size and density of the grain are most difficult for a novice to hit, and, moreover, tave to be varied with the dimensions of the picture, and very often with the character of the negative. Although I have never practically worked any of the photo- engraving methods, I can well conceive that the question of grain is an even more difficult one than is the sort of hybrid process I am now referring to, because, in addition to other troubles, there is that of getting a grain that will not too readily fill up in inking ; in fact, the grain must not be finer than the absolute exigencies of gradation require. In our present method, however, as we have no inked plate to deal with, the grain may be as fine as we please; indeed, the finer it is the softer and better will be the gradation. Here was the first trouble 1 encountered. I could not persuade myself to make the grain fine enough in, the first place, and I then rendered its coarseness more obtrusive by making the negative too dense. It is impossible to convey in a mere written description either the size of grain necessary or the density of the grain negative, because these, as I have said, vary so much with circumstances ; in fact, I am convinced that nothing but actual experience with a variety of dif- ferent " gratings," as well as portrait negatives of different kinds and densities, will enable the operator to secare exactly what he wants ; but, if he will bear in mind one or two simple points, I think he may- save himself much trouble. Let only rather thin negatives, but full of detail, be selected for the purpose, let the grain be as fine as may be without being too fine to deprive the picture of the character it is sought to give it, and let it not be made too obtrusive by giving too great density to the grating negative. It has to be borne in mind that, like retouching, the effect produced on the print is far greater than appears in the negative. As regards the production of the grained plates, that naturally constitutes the chief difficulty; I believe they are to be obtained conuiiercially,- though I have as yet been unable to secure anything satisfactory at a reasonable price, so have had to make my own;. and perhaps my experience may be of some assistance to others, as I think I have tried-eVery method I have seen- suggested or that -I-^ould suggest myself* Kuled'Screens'are, of -course, completely oiit of tlie question unless you have a ruling machine, and even then I questiott whether the mechanical diliicultieftiavol*«d.are not greater than the result justifies. I have'ti-ied photographing various kinds of gauze, iJiefiillic and otherwise, perforated zinc, perforated cafd,i<"/ hoc (/enit.i om/ie, but am always met with the-samediffipulty, namely, a perfectly even diviaon pf the originah , In any of the woven fabrics it will always be found tliat there' afo '-here 'and tfiere siiigle thrMiis or strands of different thickne'99 to'the rest, or that' (ire' badly sfpaced, and in such materials' as perforated zinc there seem to be at regiUar distances wider spaces between the lines of perforation, as if these were made by means of" February 54, 1803] THE BRITISH JOURNAL OF PHOTOGRAPHY. 119 rollers which at each revolution imparted their own irregularities to the sheet of metal. ICvery one of these departures from strict uniformity produces its effect upon the resultinj^ grain ; indeed, when this is so tine as to be scarcely distiiijruishable to the eye except with the aid of a map^iiier, tlie irrefrularities seem to be even more prominent than on the larger scale. A method of ruling, described about two years ago, in which a perforated strip of paper or tinfoil is drawn across the surface of a sensitive plate, so as to form a series of fine lines when exposed to light, seemed to promise a way out of the ruling ditiiculty, and on a small scale I found it answer very well. J?ut I was not fortunate in being able to procure the necessary tools for making the perforations fine enough to work directly, and, when the dimensions were increased to a autlicient extent to admit of reduction, the mechanical difficulties seemed to be increased out of all proportion, and I had to relinquish that method. ETentually I gave up attempting to get a mechanical grain of any kind, and turned to what may be called, in contradistinction, a natural grain — one obtained by spreading a granular substance evenly over a suitable surface. This at first offered no great promise of giving a better result, though after some perseverance I at last managed to arrive at something that seemed to be nearer the mark. The process I eventually adopted consisted in spreading the grain evenly over a flat surface, and then photographing this under proper conditions of lighting, when a beautiful erain of the greatest uniformity can be obtained, and that is more than 1 can say in favour, of any of the methods of pressing the grained surface into tinfoil or soft metal, so as to form a matrix from which to take impi-essions in gelatinous or other ink. I tried first of all spreading the granular material on glass, with the intervention of an adhesive, and, when dry, using this as a negative by transmitted light, from which to reproduce others in film form. But the result was unsatisfactory, as I could not find any grit that was translucent enough and yet gave a good grain. Such screens were, in fact, too opaque, whereas the beauty of the reproductions bv re- jiected light from a granular surface is, that you get what may fairly be called a selective grain, that prints more forcibly in the shadows than in the high lights. The plan I have used with most success consists in, first of all, stretching a sheet of paper smoothly and lightly over a nlate-glass surface, and coating this in turn with a thin solution of gelatine, spread verv evenly bv pouring it on and off asain, rather than with a brush. ^\ hen this is perfectly smooth. I sift over it. bv means of a perforated zinc tray, powdered emery, mixed in three different grades of coarseness — 10, oO, and 60, as the numbers go — and. when the gelatine has set, I shake off the superfluous powder by gently tapping one corner of the plate on the table. Then another sheet of smooth paper, and a second piece of plate glass are laid on the dusted surface, and as much pressure applied as I dare without danger of breaking the glass, in order to render the surface as smooth as possible, when it is allowed to dry. The dark tint of the emery prevents any harshness, or rather hard- ness, in the subsequent photographing, and if a good diffused light, coming principally from the front, be used, a grain may be produced by reduction that will rival in softness, evenness, and minuteness, anything in the way of photogi-avure, and give printing results upon albumen or gelatino-chloride paper that are far preferable, I think, to the mechanical " Meisenbach " grain. In effect, the prints, if toned dead black, look just like photogravures, and are no more diflicult to make, when the suitable grain negative has been selected, than plain ones. The film negatives are made on collodion emulsion, the glass being first rubbed with talc to make the collodion " strip," and, of course, the- grain may be reduced to any degree of fineness. I have been unable to get the clearest and best "gratings" by using the process of reversal by means of nitric acid or ferric sulphate, but by the direct method no difficulty will be experienced if too strong a light be not used, and no attempt made to get density. The grain negative should be as delipate as posj^ible. The trouble of spreading the emery may be saved bv using ordinary *mepy cloth, if it can be got free from cracks and crea.«e», and is strained evenly on a flat surface; but I prefer to spr'od the powder myself. W. Lindsay. PROPOSED NEW CENTRAL PHOTOGRAPHIC CLUB AND INSTITUTE. We have received the following oflicial communication on the subject : — A PBOPOfiAL has recently been discussed and adopted by a providoDal committee, having ior Object the establishmeut of a photographic club and institute, occupying a central position in London, easily acoeisibla from the principal railway termini and by the chief omnibni routes, « heated ones which ?hl ,^^w °l'°.r- These buraiAers can \>o multiplied to any extent to give rae photograph the required polished or en^imelled suiface, and can be placed any distance from each other according to the size of the card, or by placing carrier rollers between, any size of picture can be thereby worked through the same machine. I arrange for these burnishing rollers to work either by strap, chain, or endless-screw movement. The burnishers are locked by a bar, which runs along the side of the frame and fits in a groove of each, and this is fastened by a screw. By loosing the screw the bar can be slided along, and all the bur- nishers are then free. The machine is made in its various portions of wood, metal, and other materials which appear most suitable, and is fitted with the necessary wheels and cogs to work it by power — gas, steam, or any other motive power — or it can be divided into parts and worked by hand, either treadle, crank, or handle. When the machine is set in motion the box is placed in position for the brush to come properly over it for pasting the picture to attach it to the card, the latter being brought down upon it by an ajiparatus arraugeil similar to tlie ordin.ary printing press, as previously stated. The picture being fixed on tlie card, the pegs are released by a catch, spring, or other similar automatic device, and passes on to the revolving sheet, which is bfetween the two sides of the framework, and in passing under the first set of rollers before described the processes known as dabbing and squeegeeing the picture to the card are performed, it passes along to the drying part, and then over the lubricating or soaping roUers, and finally between the rollers and burnishers, and is then delivered into a box, finished in every respect. If it is desired to have a picture not lubricated, I arrange to divert it after leaving the|drying apparatus part to a set ol rollers, worked on the same principle as the rollers of the burnishers, and it is then finished as a rolled picture only, and delivered into a box the same as the above. It will thus be seen, from the above description, that a jjieture is never handled .ifter being put into the box from the washing process until finisheil, wliich is a great advantage, causing it to come out cleaner and better finished. My machine will enable the various processes of photographic work here described to be performed by power, and in consequence there will be a great saving of labour, fewer assistants being required, and the process will be nioie perfect in its action than the present methods of hand labour. Improvements in Shutters job Photographic Cameras. No. 4122. Edward Howard Pekcv Hu.mphrevs London. — Januan/7, 1893. 8, Hyde-park-gate, My invention has reference to shutters for pliotograjihic cameras, and it consists in foi-ming such shutters of a tube having two openings or apertures diametrically opjinsite each otlier, or of a solid rod or bar having an opening or aperture formed through the same at right angles to the axis. The tube or rod is free to be t»rney its reaction strains the nuiterial tight. To prevent the unwinding taking place too freely I provide a l)ar which presses against the film roller ; tlic bar is carried by two springs which are attached to tlie roeking fhvme. mtetiriQ^ of Socutte^* MEETINGS OF SOCIETIES FOR NEXT WEEK. Dat< ot KMtlng. Name of Society. Febmary 27 ; Camera Clnb „ 27 ' Dundee Amateur „ 27 Lantern Society „ 27 North Middlesei „ 27 Putney „ 27 Ilichniond „ 28 Birminifham Photo. Society ... „ 28 Great Britain (Technical) | 28 Hackney „ 28 Halifax Camera Club ,. 28 Lancaster „ 28 Leith „ 28 Newcaatle-on-Tyne&N.OonntieE 28 Pai-iley „ 88 Rochester „ 23 Warrington , March I | Kdinbnrsrh Photo. Society „ 1 Leytonstone „ 1 Photographic Olub ,, 1 Sontbport .. 1 ' Southtea „ 1 ! Wallasey „ 2 ] Birmingham Photo. Society ... ,, 2 j Camera Club Place of Uaetlng. Dundee and East of Scotland . Glasgow Photo. Association.... Gloesop Dale Hull Leeds Photo. Society London and Provincial Oldham Tunbridge Wells Brighton and Sussex Cardiff Croydon Microscopical Holi)orn Leaminffton Maidstone Hull Charing Cross-road, W.C. Asso. Stndio, Nethorgate, Dundee. 20, HanOTcr-sqnare. Jubilee House, Homsey-road, N. Boys' (.TyTiiimsium.Chai-lwood-road. Greyhound Hotel. Club Room, Colonnade Hotel. 50, Great HnsseU-st., Bloomsbnry. 206, Mare-street, Hackney. Springfield Barracks, Lancaster. 165, Constitution-street. Leith. Central Exchange Art Gallery, 9, Gauze-street, Paisley. Mathematical School, Rochester. Museum, Bold.street, Warrington. 38, Castle-street, Edinburgh. The Assembly Rooms, Higli-i-oad. Anderton's Hotel, Fleet-street, K.C. The Stndio, 15, Camhridge-areadc, 3, Kinjr's-road, Southsea. Kgremont Institute, Egremont. Club Room, Colonnade Hotel. Charing Cross-road, W.C. Lamb's Hotel, Dundee. Philoso. Sue. Rooms, 207, Bath-st, 71, Prospect-street, Hull. Mechanics' Institute, Leeds. Champion Hotel, 15, Aldersgate-st. The Lyceum, Union-st., Oldham. Mechanics' Inst., Tunbridge Wells. Pnblic Hall, George-street, Croydon Trinity Church Room, Morton-st. ** The Palace," Maidstone. 71, Prospect-street, Hull. LONDON AND PROVINCIAL PHOTOGRAPHIC ASSOCIATION. February 16, — Mr, E. Clifton in the chair. Messrs. Woodbury and Jamiesou were elected members. Examples of collotype by Messrs. Morgan & Kidd were passed round for inspection. The Air Brush. Mr. W. H. Harrison, of the Polytechnic, prefaced a practical demonstration xifthe Air Brush in working uj) bromide enlargements by .saying that it was rtniarkable for its mechanical properties and artistic results. The apparatus IS worked by air being pumped by means of a treadle into a container ; the air is ilien led up a pipe to the hand jiiece containing two tubes. By depressinf; a tliiimii piece a valve is opened and the air rushes through the two tul-ies which divi.les the current of air into two portions ; one blows a small wheel round,;and this sends the needle point backwards and forwards and passes through the lieedle would. Aoi throw o$..8ueh a Ifttge cloud of colour as a fine one. ; ,;Hr,,I,.ii TtLKee suggested tliat.atiqt might be removed by tneaiis of clean water in the handpiece and the application of blotting-paper to the surtac9, ,Tboses'" The answer given was that it could for three and a quarter inches square or parts of a quarter-plate. The front tube would have to be drawn right out -or an addition made. Tlie projecting lens should b« gootl or slightly stopped dpivu. Mr, W. H, Sodeau then read a paper on Plwto^nphic CliemUaU. The princip.'O subject he dealt with was their keeping qualities. He attributetl the jiower of keeping according to the atmosphere. A list of deliquescent chemicals jwa* given. He advocated the use use of glass stoi)per8 whidi if stuck at any time could be tapped or put in warm water. Thd Hon; Secretary had seen vaselLue recommended. Mr. GosLiso said h«v generally,, found warming In- the hand suHicient. Mr. Sodeau prooeeiled tp sajV caustic ooo'cdes the gloss and some- times joins the stopper to the- neck. ■_". Ijidjarubfeer corks were u.seful, but .siiould not be used for benzine or like) cpmpaimiis, X)eyeloping agents. were .best kept in an 'acid condition or fiUed iip.to. the &t<»piwr ol the ':"u.tle, vr ordinary wash bottles can be used ifpnrauiu is l>ept Qn.tUe ..surlaoe of ihe liquid. He .reconimendeiltlm use, of viiseliueisside t-lju neck of itJie byttlafor subs't-anccs which creep up the side, MagaBsiiiiii should .b«kej>t in .wtrU-eorked bottles, metabisulplilte potas.siura.wpuJLd keep fairly Vlell Ip papef..)l:^i^,lai)BP lumps', though not advi-iable. The strength «f auljydxous sod;>. «.■>» aboiit t^oe the strength of. tho ordinary carbonate.of soda. ,.iSiu]^urous. acid would .only turn to sulphm'ic by oxygen. ^ ■ . i. ... i. -j, r . ; 'r. > 'West London Fhotograpluc Socioij.-f-reoruaxy. li,-r^]Cr. ..V;,^or^r Hinton read a paper entitled, UpccittUsittion in Art Woric (see next Week's ■><).). In the illscussion which followed, Mr. Tripplin, whilst jiaying full deference to the views of Mr. Hinton, pointed out that photography was elevating in itself 124 THE BRITISH JOURNAL OF PHOTOGRA-PHY. [February 24, 1893 and that too high a standard of refinement in photographic work shonhl not be universally insisted npon. The majority of members Y<"-\\"'^'"''^?.;"'t'L: .'f. Umited time, and could derive great pleasure from their l^o^f P ' -X Lf they secured a picture of a view that pleased them, even though it might not pcSess all the qualities of a work of art. He admitted, however, that by wking to a high standard degeneration was prevented, ^^'i-- ^ ""™= 'f 'll^.'J on the importance of education in pictnre-makmg, and suggested that great good would result from the forming of a class of instruction m art-the rules Sf art aud composition should be well instilled. Mr. Hintox, replying to the previous speakers, pointed out the difficulty of ascertaining what it is m a picture which pieces, and of securing it. He stated that the photographer s aim should be to catch the sentiment of the subject as far as possible. He would not be bound by rules of composition, which were scientific, and thus opposed to the artistic. He suggested that good would be derived from com- petitions in the illustration by photogi-aphy of a given subject. Mr. hELB\ disaereed with Mr. Hinton on the importance of rules of art, stating tliat it waHiecessary, particularly at first, to have a grammar to work upon. Mr. Whiter aoree.1 with the objections of Mr. Hinton to rules of art, and deprecated the copvin" of the methods of tlie painter. He would take what was pleasing to the eye, and he strongly urged the advisability of cultivating the technical side of photography as an aid to the pictonal side. Mr Winter concluded with a candid criticism on some of the photographs exhibited by Mr. Hinton, and the discussion closed with a vote of thanks to the lecturer. Greenwich Photographic Society.— February 1, Mr. H. H. Turner, M.A.. F R.A.S., in the chair.— Mr. W. E. Debenham gave an exhaustive demonstra- tion' of transparency-making by the carbon process. At the conclusion of the practical portion a few lantern .slides produced by this process were pro- jected and it is worthy of note that there was an entire absence ol any evidence of relief in the slides thus submitted. Mr. Debenham was thanked for his interesting lecture. The following were elected members of the Society :— Professor Lambert, M.A., Messrs. Parrett, Unckham, Parsons, and Holliss. The Committee announced that in view of the Society's youth they had decided to postpone date of closing entries for Lantern Slide Competition, (originallv January 31), till April 30, and to admit slides made fi-om negatives taken at "any time jirovided no awards had been previously gained. On the proposition of Mr. Haddon it was unanimously resolved that the Greenwich Photogi-aphic Society alliliate to the Photogi-aphic Society of Great Britain. Woolwich Photographic Society.— February 9, Mr. W. li. Dawson in the chair.- CoiTespondence between the Hon. Secretary and Mr. R. Child Bayley respecting affiliation with the Photographic Society of Great Britain was read to tlie members. The proposal was warmly received, and it was unanimously resolved that the Hon. Secretary take steps to apjjly for affiliation. Mr. L. E. Morgan then proceeded with a demonstration on "Amidol," the leading features of whicii have been reported in this JouBN.vL. It should be said that the meeting was highly pleased with the results obtained. Croydon Camera Club.— February 13, Annual Meeting. — The report and balance-sheet being presented and adopted, the officers and Council for the cniTent year were chosen as follows : — President : Mr. Hector Maclean, F.G.i^.— Vice-President : The Mayor of Croyd(m (Mr. F. Fass, .J.P.), the Hon. Sydney Herbert, M.P., Messrs. F. T. Eldridge, J.P., and B. Gay Wilkinson.— t'oM/fciV ; Messrs. .Frost, Hirst, Holland, Isaac, Neeves, Oakley, Packhaiii, and Wratten.— TVeaswrer ; Mr. A. G. Sargeant— J?"o«. l^xretary : Mr. G. P. White, 55, Albert-road.— ffo«. AssiMnnt Seeretary • Mr. S. E. Burrows. The meeting wafi well attended by the members, and a large col- lection of prints, lent by Mr. E. J. Wall, was displayed upon the walls. On the proposition of the Pi-esident, and supported by several influential mem- bers, it was, ncm. con., decided that tlie Club be forthwith affiliated to the Photogi-aphic Society of Great Britain. It was also resolved that, after the present month, the ordinary meethigs be held upon Wednesday in each week instead of as now, Monday. The annual dinner of members and friends is fixed for March 8, at the Greyhound Hotel. Tickets, price 4s. eacli, to be obtained of the Secretary. The particulars and regulations of the local Exhi- bition, which will be open for four days and evenings, on April 5, were read and ajrprnved, and ordered to be printed and circulated. Tlie Exhibition will he held in the Braithwaite Hall, and will be inaugurated by the Mayor. Aston Natural History Society (Photographic Section).- February 9.— Mr. Walter Tyler gave a paper entitled Hmo to Develop on Tour. The lecturer practically demonstrated how exposures could be tested by a. few plates being developed while on the trip. With such simple means as a few pieces of WUlesden paper folded for dishes, an ordinary window-blind lath on a knife edge for an extempore balance, and some ruby fabric round a candle- stick on a penny for his lamp, he showed how practical, if not orthodox, development could be performed while away from home. A piece of card, 4i X 3J, cut in the middle, and hinged by stamp paper, on which was laid the sensitive paper and then the negative) served as his printing frame, the whole being secured by two elastic bauds. Table, dessert, and teaspoons acted respectively as his one ounce, half-ounce, and drachm measure, while three- penny pieces were used to weigh his one ounce of hypo, and a sixpenny piece five grains of pyi'o. Birmingham Photographic Soc ety. — A large and appreciative audience assembled in the larM lecture-room of the Y.M.C.A., Needless-alley, on the evenhig of Tuesday, the 7th inst., when a paper was read by Mr. C. .T. Fowler on The River Severn, from its Source to tlie Sea. The lecture was illustrated by a series of 300 excellent slides, the outcome of a survey of the river under- taken in 1891 by Messrs. Middleton & Fowler, when upwards of 400 pictures were secured. The course of the river from the point where it rises in a swampy hollow on Plinlimmon to its reception by the Bristol Channel is replete with interest, and some of the more famous places, such as the cathedrals of Worcester and Gloucester, Berkeley Castle, Buildwas Abbey, Much Wenlock Priory, Tewkesbury, Bridgenortli, &c., of which very fine pictures were shown, elicited hearty applause. In addition to this, the com- pleteness of the subject added very much to its interest. Bristol and West of England Photographic Association.— Febraary 10.— It was decided the hold the meetings fortnightly instead of monthly, and that a question box should Ije started. Burnley Photographic Society.— The Annual Meeting of this Society was held oil the 1st inst., when the l)alance-sheet, which was fairiy satisfactory, was adopted. Mr. .Jno. Butterworth, J. P., was re-elected President, and Mr. J. Altham Secretary, and Mr. A. H. Kellet Treasurer, in place of Messrs. Sutcliffe aud Lee resigned. The following were elected to the Council :— Tlie- Rev. T. Layland, aud Messrs. T. Ormerod, V. Dunkeriey, J. Holgate, J. L. Lee, J. J. H. Bell, A. Howarth, aud W. H. Hoghton. Derby Photographic Society.— February 14, Mr. Keene presided.— The Hon Secretary brought forward a circular which had been received from the Photo-raiihic Society of Great Britain, in connexion with the affibation scheme, ami after a short discussion it was decided to join with the PhotO' graphic Society of Great Britain. Mr. Porritt (President of the Leicester Society) gave a paper on Isochromatic Photographtj. Mr. Porritt had to illustrate his paper a set of negatives of stained-glass wnidows, also a hand- painted set of designs for same, to show what an amount of gradation could be obtained by means of isochromatic plates with the use of a yellow screen. He also had a large number of lantern slides, one set being from negatives taken on ordinary plates, and the others of same subjects taken on isochroiiiatic plates, Mr. Porritt passed round a few yellow screens of different tints, and explamed whicli, in his opinion, was the better way to make them. Leicester Photographic Society.— February 10, Mr. J. Porritt in the chair. —It was decided to hold the meetings on Thursdays instead of Wednesdays after tlie summer recess. The President then read a paper by Mr. A. B. Webber, of Bromley, on Isochromatic Photography, who sent a large number of paintings, transparencies, and fifty lantern slides to dlustrate hi.s sulyect,. and proved a most useful stimulant to the members who work in that direction. The results of isochromatised plates were still more definitely shown by the useful method of showing two prints or lantern slides of the same subject with iso and plain plates, and which were exceedingly useful in showing the value- of the prepared plates. The church windows shown by Mr. Webber were admirable examples of the process, as also several differently coloured chrys- anthemums in variously coloured vases, also (several other tests of colouring, as wools, cloth, &c., whch amply illustrated the utility of the process in coIom photography, and in maintaining the value of tlie visual colour scale. Liverpool Amateur Photographic Association. — February 9. —Dr. Charles A. Kohn, of the University College, delivered to the members a lecture on Chemistry of Photography. He illustrated his remarks with interesting experiments in "a very clear and lucid manner, demonstrating the mystery ot tile action of light and formation of the latent image on the pliotographic plate. Other similar practical lectures follow every Thursday until the end ot April. Sheffield Photographic Society.— February 7, Mr. B. J. Taylor m the chair —Mr. J. W. Charlesworth opened the discussion, " Was amidol a good developer for lantern transparencies f whicli was taken part in by most of the members present, and eventually decided that, given a good negative, warm, tones could be produced. South Manchester Photographic Society.- Mr. R. B. Barningham in the- chair —Mr C. Lord described a ramble through Switzertand witli a camera. The tour was taken in tlie summer of 1891, the party consisting of two parsons,, a merchant, a doctor, ami a lawyer. This was the ftftli time, said Mr. Lord, that lieliad visited Switzerian.I, but the tirst time with a camera. Tlie party went to Antwerp by way of Harwich, and train was taken for SohafFhausen and the falls of the Rhine. The first impression of tlie falls was disappointing. The height of them is only about sixty feet, but the breadth is neariy 400, and they have the appearance of supendous rapids rather than a cataract. It is only by drawing close to tlie falls that their vast magnitude can be realised, and the immense volume and force of the water estimated. One of the great attractions of Switzertand is Cloudland. Clouds are always brighter and more varied m mountainous than in flat regions. It is beautiful to watch clouds from below sailiu" quietly along or scudding before the wind, and mark the transfaguration wrought by the glow of the setting sun. But to his mmd it was more wond'erful to look down upon the clomls from some peak high above the cloud line. , r i.. Amateur Photographic Society of Madras.— January 12, Annual Meeting^. —After the transaction of other Inisiness, a grant of 2/. 2^-. was made to the Photofu. .wwc T.h l-cWASHTNG CB.T FILMS. 3 »*;T re washing cut films, that, if he lays them whilst wet on spoil* negative glasses, they will adhere firmly by suction, and can then be stood up in the washing rack and treated just as though they were ordinary glass negatives. Although there is probably nothing at all original about this method of washing films, I cannot remember to have ever seen it in print. — I am, yours, &c., J. E. Hodd. 4, GoUUmith's-gardens, Acton, February 11, 1898. To the Editor. Sir, — May I suggest, in reply to jour ecrreepondent A. Levy's query NATIONAL ASSOCIATION OF PROFESSIONAL PHOTO- GKAPHERS. To the Editob. Sib, — As I presume you will have some mention of the meeting of above at Manchester, on Thursday last, I cannot refrain from a word or two, urging the attention of my brother professionals and this Society, and I venture to hope that you will kindly add your own opinion as to the importance of the Society to our trade, as a trade generally. My excuse, if one be needed, for this letter, is that I am probably one of the latest members, and I feel sure that photographers, as a body, are neglecting their own interests by holding aloof. For many sound and solid reasons it is high time we united, for argue and talk as we may, it is a solid fact that the bulk of photographers are not making fortunes ; the big men are, of course, all right, but the owner of the small provincial business, no matter how good and clever a man he may be, is not by a long way so well to do as those in a similar position of twenty or twenty-five years ago, and one of the reasons is to be found in the amateur. I don't say this with the slightest ill feeling, but the truth remains, all the same, that many of the dealers and stock houses cater dis- tinctly for amateur customers to the decided detriment of the working photographer. I send you herewith circular just received, and better proof I could not give. Now, one of the dealers here is a top shop and fancy goods depot, two others are chemists, and it is obviously an attempt to get these people to cater for amateurs. It is time all this were put a stop to, and it can only be done by the combination of all business photographers. It is impossible in space of a letter to go into all the reasons for a genuine trade society, all I would urge is, that every photographer in the kingdom should look into this for himself ; almost evfery trade or profession of any merit or standing has its society, and the want of such an one in our trade has been the cause of endless abuse and loss to the workers. — I am, yours, &c., " Unitas." February 14, 1893. INTENSIFICATION. To the Editor. Sir, — Not understanding chemistry, I generally pass over articles con- taining chemical symbols, but as most operators are interested in mer- curial intensification, I thought I would make this an exception and try to get some meaning out of Mr. Chapman Jones's paper in last week's British Journal of Photography, entitled, " A Chemical Study of Mer- curial Intensification." Not being a chemist, I cannot be said to be an experimentalist, but have worked on the principle of sticking to one plate, one developer, one intensifier, and one reducer, and carefully watch the results and thoroughly understand their power by observation. Now there is one remark I note in Mr. Jones's paper, under the head of " Practical Conclusions," where he says, " It is impossible, uithoiit falsifying the gradation, to develop too dense, and afterwards reduce to the desired condition." 1 will now give my method of intensifying and how I use it for re- ducing an over-developed negative toithout, I think, falsifying the gradationsi Intensifier, Sat. sol. bichloride of mercury 2 ounces. Iodide of potassium, about 2 drachms, added to the mercury until the scarlet colour is almost vanished, then add 8 or IG ounces of water. To intensify, I. flow. the plate with the above until the correct density . is obtained ; afterwards fix without washing in hypo, not too strong, and wasi well, of course, after^yards. Now to reduce a' negative, no matter how dense it may be, I flow with intensifier until the iodide of mercury Jjasupiformly changed the plate or, rather, film. , I tlien, witlumi wq.»J'iiig, take the plate, from intensitier and dip in an upright bath of recrystalHsed cyinide of potassium — you will .then note a negative that would perhaps take arweek,in good4ighlf, to print — rapidly and uniformly reduce with the most delicate gradation of light and shade. I only intensify "On rare occasions, and the same- thing applies to reduction, beoaue I like to regulate my developing in; such a way that the:correct rende.ring of the lighting is obtained; but I think a «ure intensitier and certain' reducer is^a most phasing power in the operator's hands. I also find the above reducer very useful in removing silver stains from gelatine negatives. — I am, yours, &D., Alfred E. DightoH. 22, Mount Ashroad, Sydenham Hill, London, February 5, 1893. February 24, ISOS] THE BRITISH JOURNAL OF PHOTOGRAPHY. 127 BLISTEIIS. To the Editor. Sn;, — Your correapondent, Mr. A. Levy, seems troubled with, the use of the new methylated spirit as a prophylactic in the case of blistere. Before 1 Rave up the use of albnmenised paper I was now and again troubled with them, until the cure— so far as the brand of paper I was then using was concerned — came to me by chance. Whilst toning I found I Iwd no hypo prepared. I hastily got some ready by suspending a muslin bagful in some very hot water, and by the time I required to put my prints in it was still quite warm. No blisters rose. I tried re- peatedly afterwards, waiming my hypo, and never had another blister. I should be glad if this method may bring Mr. Levy and others relief. — I am, yours, itc, J. Cirtkk BnowNB, D.D. Thuriiing Rectory, Oumlle, Feb. 6, 18!)3. Slncujerjs to Corrcspontientg. *,* All matters intended for the text portion of this Journal, includimi meries and Exchanges, must he addressed to '' The Editor, The Britlsh JOL'RXAI. OK Photograi'HY," 2, York-street, Covent Garden, Lcmdon. In- altenlion to this ensures delay. PflOIOQKAPE ReOISTKRBD : 8. V. Wliite, Reading. — Vhotograpk of William Isaac Pahnei\ taken on March. 14, 1885, hut not luMished \mHl Januori/ 28, 1893. I'uzzi.KD. —Such an article will appear shortly. Laxterxist. — There is practically uo los.i of light when using the long instead of the short-focus lens. W. II. — Either A or B will answer your purpose. Not having seen C or D, we c-iniiot speak of them from personal knowledge. lGNORAMl"s. — Try the effect of warming the solution. Are you sure you are eniployiiig the solution at a uniform temperature < AViLU.AM Webb. — We believe the article is the subject of a patent, but we must dc'-hiie to exjiress an opinion as to its validity. W. B. — .Ap[ ly to Messrs. Kvre & Spottiswoode, New Street-square, who are the proprietors of the Woodbury Company's business. 51. PowEi.i. — We cannot supply the details of the processes you allude to. not having cognisance of them. Had you not better employ a patent agent ? J. HiOHKiEi.i).— I. The Studio and What to Do in It, by H. P. Robinson (Piper & Carter), will probably give you the desired information. 2. Yes. W. Freeman. — As both lenses are negative, no matter how they are placed in relation to each other, their sum will be negative, and they will nOt form an image. Engraver.— In the Journal for April 8, 1892, you will find two articles describing how subjects may be photographed on wood for engraving purposes. T. J. — There are several firms of photographic dealers at Cape Town. The prices of photographic goods are somewhat higher we believe, freight, &c., having to be taken into account. K. A. Symes. — Tlie stains are caused by the nes.itives not being sufficiently washed between the different operations. Unless this is perfectly carried out, stainmg is very prone to arise with mercurial intensification. RoDNEL. — You have so good an idea of the apparatu.'i that we should think you would be able to construct it for yourself. The arrangement works per- fectly, any lantem-niaker wouldjbe able to construct it from your description. A. Muirhead. — You wouM be infringing the patentee's rights by making the camera for your own use or to dispose of; and even though you were not, we cannot reconcile it with proper conduct to copy other people's manu- factures. B. C. Curtice.— You can cure the distortion in the photograph when copying it by either tilting the photograph or swinging the back of the camera. See that the vertical lines of the temple are parallel with the frame of the ground glass or focussing screen. Neko. — To engage in photography on the sands at the seaside we believe it is necessary to procure a permit from the town authorities, most of whom now (happily for the visitors) regulate the number of photographers by licence. Apply to the Town Clerk. CouJSEi. GuBBixs, M. D., and other correspondents. — Mr. Frank Haes informs 08 that the tieiible steel tuhiing to which he referred in his recent letter may he obtained from the I'nitetl flexible Metallic Tubing Company, 86, High Holborn, W.C. We 3o not know its price. W. Lloyd. — The picture is not distorted, but the perspective is very violent. This is caused by the interior being taken with a very short-focus or what is known as a wide-angle lens. Wlien such wide angles are included the pictures always have an unpleasant appearance. J. Brown. — Si'ots, such as those on the print sent, may proceed from several cauHcs, such as want of care in the manipulation", impurities in the cement with which it is mounted, deleterious matters in the mount, &c. By merely look in;: at a print, it a obriously impossible to say from what source such spots proceed. Exi'ERiMtXTAUsT.— We could give yon a formula for photo-transfer ink, but it would be very troublesome to make in small quantity, aud probably in iuexperienced hands would not turn out natisfactory. Better buy it ; you will then get a reliable article. It may be had from any dealer in litho- graphic materials. J. Hawkkh Smith (Bowbridge, near Stroud, Gloucestershire.) — Messrs. Kilaer Bros., King's Crosji, supply such l>ottIes. E. Wilton.— No tax, we lielieve, u payable for a horte and trap, jirovideil they are used solely for trade purposes, iind photography woold he cUsneil a.s a trade. But if the horoe or vehicle be used at any time for other than business purposes, it would at once become liable for the tax. Tlie name and address must be legibly written on the right hand side of the trap. Len.s — If a lens of the rectilinear type of eighteen inches focus will not cover sharply, a 12x 10 plate with a stop equal to f-Z'i, it must be a very faulty iiistniiM>'nt. As the lens was supplied subject to ajiproval, it should be returned without delay. A lens is not necessarily bad because it bears no maker's name, though a name is generally some guarantee of quality. G, W. C. — \. The Euryscope named will serve your purpose quite well. We speak from |iersonal experience, 'i. The query as regards plates you must ascertain for yourself. It involves our nuiking comparative trials of the twenty-three brands you tabulate, which you, as a rea-^oiiable man, could not expect us to make. 3. From Piper & Carter, publishers, Fumival-street, London, E.G. R. 0. S. complains of "an opalescent coating on his lantejn sliiles when he developes with the ferrous oxalate. He says that with pyro or amidol he does not get it." — The coating complained of is oxalate of lime from lime in the washing water. It can, however, be easily removed by immersing the slides in a very dilute solution of hydrochloric acid. A few drops of the acid to each ounce of water. T. Wallace. — The best information that has been publislieil on retouchina is that given in the two .series of articles by Mr. .Iledmond Barrett that appeared in our pages. Study them well. A few practical lessons from a good artist will then be all you require. 'The services of retouchers are not so well paid for now as they were some years ago, except in cases of excep- tional .ibility, by first-class houses. ' Lancashire Lad. — Tliere are two sides to most questions ; but. according to your own statement, you were entirely in the wrong. What you were asked to do was the legitimate work of an assistant, and youf positive refusal to do it, cou]>kil with the strong lauguage you say you used, though you may now be sorry for it, we should say would, in the County Court, be considere, 6. We do not know. 7. We have had no experience of the shutter. 8. If you have arrived at the size you wish the oliject on the pl.ate to be, the table will give you the remainder of the information. 9. Roughly, the equivalent focus of the lens. S. W. says : "I am much troubled with my prints sticking to the negative while printing, particularly in the summer, and also just lately, when the printing room was unusually warm. I use a varnish sold specially for gelatine plates. Can you suggest any remedy '"-The only thing that we can suggest is that another kiud of varnish be tried. The varnish may, however, not be at fault, for we found, some years ago, that if the film contained hyposulphite of soda, although a reliable varnish was u.serize in open competition. No size limits ; but if hand-camera work, then not less than four prints on one mount. Prize, bronze medal. Entrance fee, 2s. each. F. Any Subject : Open to all Surrey photographers who have never won a prize in open competition. No restriction, except that hand-camera work must be entered not less than four prints oiieach mount. The winning print or set in Class F. will be reproduced in Woodbui^gravure, and the ]irize consist of forty copies thereof presented to the winner, besides which a cojiy will be sent to each competitor and to eadi member of the Club. Entrance fee, 1*. 6d.; members free. (i. E.xhibits by Members : Not for competition. H. Works of Distinguished Pliotogi-aphers : Bv invitatirm onlv. Not foreomiietition. Further particulars may be obtained of Mr. G. R. White, 56, Albert-road, Croydon. Forfarshire International Photographic Exhibition.— The first Ex- hibition will be held in the Reid Hall, Forfar, on Thursday, May 4, 1893. and following two days. The following are the officials : — Jinn. President : Alex- ander Robertson, of Bumside, Sheriff-Substitute of Forfarshire. — Hon. I'tce- Presidenl: Robert Wliyte, Procurator-Fiscal of Forfarshire. — Chainmu of Cmnmitlee : tUlbert W. Don, Clocksbriggs House. — Vice-Clu/Arinan : J.Watson C^aik, Yot{a.r.— General .Secretari/ : W. .1. Anckorn, ArOroath, N.B. — Trea- surer : R. Bruce, Banker, Forfar. — Local Secretaries ; A. H. Simpson, Chemist, Forfar ; James D. Ross, 6, High-street, Brechin ; and A. Davidson, Chemist, Montrose. 'The Classes for Competition are as follows :— Class 1. Am.ateurs confined to Forfarshire, any subject, any printing process, irrespective of size. Class 2, Amateurs, Open Class, Landscape and Marine, irresjiective of size or process. Class 3, .•\iiiateur, Oenre and Portrait. Class 4, Professional, Por- traits, irrespective of size. Class 5, Professional, Genre. Class 6, Open Class, Enlargements, untouched. Class 7, Professional, Landscape, with or without Figures. Class 8, for Ladies only, any subject. Class 9, Open Class, Lantern Slides, set of six. Class 10, Medalled Class (Champion), no restrictiou in number of picture-. One gold medal will be awarded to the best picture in the Exhibition ; also a silver «nd a bronze medal will be at the disposal of the Judges for any special photographic work, any subject or process. *»* In tvpe, but unavoidably hehl over, articles by Hector Maclean, T. Nr Armstrong, J. Pike, W. H. Davies, a paper by Mr. Horsley Hinton, and othe. interesting communications. These we will endeavour to overt.ake next week. OONTBMTB, Faox PHOTOCrBAPHINO STAGE SCENERY .. ii.l AMATEURS' UACKOROrXDS AND ACCKSSORIES.— II 114 ON THINGS. IN GENERAL. By FREE LANCK 115 A NKQLKCTED DEVELOPER. By W. B. BOLTON 110 RETOUCHIXG ANI> VAHNISflES. By - HAYNKS WKLCH IH DETEUMINATION OK PLATE SP"EI1S. Bv K. HCRTKU *KD V, C. liKIKFIELI) UH IMITATION PHOTO-EXORAVINOD. Bv W. LINliSAV lis PROPOSKll NEW CKNTIIAL PHOTO- GE.U'iIlC CLUB AND IXSTITUIE .. 119 PArf;: WOOLWICH PHOTOGRAPHIC SO- CIETYS EXHllUTIUN in THE PMOTOOHAI'HIC SOCIETY'S LECTURES (IN ,'• PHOTOGRAVURE " l'2(i THE PHOTOGRAPHERS' BENEVOLENT ASSOCIATION ; I'^tl DURHAM CITY CAMERA OLUB EXHI- BITION I'il RECENT PATENTS 181 MEETINGS OK SOCIE TIES !«» POKTHl'OMING' EXHIBITIONS 191 COUUESPONDENCE ^..._^HJ ANSWERS TO CORRESPONDENTS...... 187 THE BRITISH JOURNAL OF PHOTOGRAPHY. No. 1713. Vol. XL.— MARCH 3, 1893. PANOIIAMS, WIDE ANGLES, AND PERSPECTIVE. A\'iiu,K it nmy lie difficult to indicate a sharp lino of division between a narrow and a wide angle of included subject iu a photograph, a like difficulty does not prevail as to the nature of the perspective in which such a picture is presented. The Panoram, as given in the title to these notes, differs from the ordinary camera iu this, that whether a wide or a narrow angle of view bo included in the picture, the perspective is not plane, but cylindrical or panoramic. The Panoram — as doscribetl liy its inventor. Colonel Stewart, ll.E., at the meeting of the Photographic Society of Great P>ritain on Tuesday evening— is a camera containing several ingenious devices. A fair idea of its nature may be had yf we describe it as a Johnson & Harrison pantascopic camera fitted with an Eastman roll-holder instead of the dark slide for glass jilates which characterised the elder invention. The principle of the camera mentioned permits of its taking in a view that includes the whole circle of 3()0 degrees, but as it was intro- duced anterior to the days of 61ms and when glass plates formed the sensitive support, it was evidently impossible to utilise plates so abnormal iu length compared with height as to give practical effect to its possibilities, hence 120 degrees was fselected as an angle sufficiently large. By the application of the Eastman roll-holder the original great bulk of the instrument is minimised to such an extent as to reduce it to that of an ordinary portable camera. As the image falls upon the sensitive surface throvigh a narrow vertical slot immediately in front of the film the roll-holder does not necessarily exceed a veiy few inches in width. The camera rotates upon its stand, the axis of rotation being the focal centre of the lens ; and the slot through which the light passes to the film is of unequal width so as to allow of a greater practical exposure being given the foreground than the sky. The motive or driving force is clockwork, as in the pantascopic camera, and this likewise causes the revolution of the roll-holder by which the film is carried across the plane of delineation at the focus of the lens. A complete rotation of the camera (the one exhibited had a lens often inches focus) ensiires the covering of a baud of film a little exceeding six times the focus, which in this case would form a continuous picture over five feet in length. But while the camera possesses this giant's power it is not necessary that advantage be taken of it. On the contrary, the clockwork after being started may be stopped at any stage by the mere manij)ulating of the pneumatic ball, and the exposure may be such as only to include an angle of the smallest con- ceivable dinieusieafc, if the gul;\}ect be one that does not warrant more being included. The termination of the rotation ensures the marking off of the portion of film exposed by the action of a pricker, after which the clockwork is wound up and everj-- thing is in readiness for the next exposure, which may include either a wide or a narrow angle of view as before. An ingenious method of developing these long pellicular negatives has been devised by Colonel Stewart. He fastens the exposed band to the periphery of a wheel of suitable width, and then rotates it slowly in a vessel of developer, which need not be any larger or deeper than just to submerge the film. Several negatives of this class which were exhibited attested the success wliich attends this novel and ingenious system. A similar method may be adopted with the printing from films of great length. A camera of the nature here indicated, while useful for such pictorial purposes as involve the depicting of any subject in which there is continuity, such as a range of hills, a chain of lakes, or a coast scene, must prove of special value in military reconnaissance, and it will form a useful addition to our appliances. But it may be said, as the perspective of such pictures will be cylindrical they will necessarily be distorted. To meet this, we may say, speaking hypercritically, that photographs of every kind are distorted if they are not looked at from the correct point of view. When this is attended to there is no distortion in pictures in either plane or cylindrical perspective; otherwise there is. Let a number of spheres be placed squarely in a row in front of a camera containing a wide-angle lens and then be photo- graphed. A careful examination will reveal the fact that, while the central one is of the same height as that nearest the margin, yet the latter is not circular but elliptical, the width ex- ceeding the height in dimensions. The central one is quite circular ; but, in proportion as the others recede from the centre, so does the horizontal width increase. This arises from a circular beam of light being made to impinge obliquely on a flat surface. No picture whatever can be seen with absolute accuracy unless the eye or point of observation be opposite the centre of the picture, and at no greater distance from it than the focus of the lens by which it was taken. Only in this way will the elongated marginal spheres adduced iis an example be seen as spheres. A similar principle applies to the examination of a panoramic view. To see this with accuracy, the picture must be bent in a curve, the radius of which equals the focus of the lens, and the eye nmst be in the centre of the curve, so as I to be directed squarely to each part. No distortion will now ) 1)6 apparent. 130 THE BKITISH JOUKNAL OF PHOTOGRA.PHY. [March 3, 1893 WASHING PHOTOGRAPHS. We make our title as wide in its scope as possible, as we pro- pose to include in our purview not only negatives, but prints of various kinds. We are led to consideration of the subject owing to inquiries, familiar enough to anyone known to have experience, as to the cause of this, that, or the other kind of spot which, in even a brief practice of photography, exercise the mind of the tyro, and not only him, but, not infrequently, the expert. It is not our purpose to write a disquisition on spots in general ; we have in view a particular aspect of the subject — those spots attributable to the water employed. First, lot us say that we consider efficient washing of prints may be done with an ex- treme maximum of twelve hours, if properly carried out ; with negatives, a maximum of four hours may be considered sufficient. We refer to this point as, from personal knowledge, we can say that some workers considerably exceed these limits. One amateur who came to us with a tale of unavoidable " frilling," was astonished when we informed him that the twenty-four hours' washing he gave his plates was the cause of his frilling, and was almost incredulous when he learnt that he might con- sider from two to four hours am]>le time to leave his negatives in a running stream of water. Then, again, the universal con- sensus of opinion from printers with extensive experience is, that prolonged soaking injures the quality of the print. Tlie condition of the washing water is a prime factor in the production of spots and stains of an extensive and varied character. It will only be necessary to briefly allude to hard waters, in which a large quantity of carbonate of lime is held in solution by carbonic acid. Such waters are fruitful in pro- ducing negatives with a closely adherent scum. Again, waters of a ferruginous character deposit iron under some conditions, and so stain the prints. This cause, when the iron is not very largely present, might possibly escape attention. But the foremost cause of all, whether running streams or water from a public main is made use of, is the presence of suspended matter. Good samples of water, fit for use as a beverage, may, in average conditions of purity, contain so much suspended matter as to cause a deposit of more or less fineness over every print or negative placed under its influence, even though the impressed surface may be placed face down in the trough or other receptacle. The suspended matter may be fine particles of inorganic matter, or, what is more probable, low forms of vegetable life that have either escaped through the interstices of the filter bed or have germinated in the water in its progress through the mains. If any one supplied with what he deems the purest of water will merely attach round one of his water taps a piece of clean flannel, and allow the water to run gently through, he will, in the large majority of cases, be surprised at the amount of " dirt " he will in an hour or two find arrested by even so open a woven fabric. Such matter will largely attach itself to photographs in washing, and produce a faint, though decided, scum or discolouration, which occa- sionally forms in clots, and gives rise to distinct centres. But it must be remembered that, as the water mains them- selves become coated internally with a deposit from the water passing through them, this is liable to be disturbed when alterations are being made. A neighbour, for example, is having his water supply altered. What is the result? For some hours, perhaps, the water is dei>,idedly muddy, and if negatives or prints be washing it is quite possible that all this muddy water is being used, and its presence never observed. Especially is this so with prints which are being washed through the night, as is so generally the case. If a cistern is used and the water not taken direct from the main — an excellent plan in one direction, as it ensures constant pressure — a portion of this mud is intercepted, but not all, and the further evil remains of a portion of this accumulation of mud some day or other surely being disturbed and despatched to its innocent victim, a batch of photographs under washing operations. Again, many stone cisterns are not kept air-tight, some not even covered : atmos- pheric dust is bound to accumulate and be deposited upon the pictures being washed. Instances could be multiplied, if need be, to give point to the obvious moral. All water for washing purposes should, before entering the washing trough, be passed through a filter of some kind. Wc look upon this matter as one of prime importance, but one which is neglected in by far the largest proportion of cases. How the water is to be filtered we need not indicate. A home- made filter of two thicknesses of flannel is used in some studios we are acquainted with, and very frequently, we are informed, have they to be cleaned or renewed. There are numberless filters upon the market to suit the most fastidious taste. We have one suggestion to offer. Whether the filter be one to discharge filtered water into the store reservoir, to filter it after storage, or to attach direct with the main and supply filtered water as the tap is turned on, in any of those ca.ses let the filter chosen be one that is readily cleansed and its contents removed, or, better still, one that is selfcleansing. Many excellent filters of the latter pattern can be obtained ; the matter is rather one of embarrassment of choice. In con- clusion, let us say to all photographers, Filter every drop of water you use, and use a self-cleansing filter for the purpose, and so avoid a fertile source of spots and stains. WARM TONES WITH IRON DEVELOPMENT. Althougu the class of tones usually associated with iron de- velopment— by which, of course, we mean ferrous oxalate — ranges only between grey and black, yet it is by no means im- possible, under certain circumstances, to obtain warm tones, as all workers of Alpha and similar papers are aware. But the conditions requisite are such as to practically bar the applica- tion of this method in a great many instances where protracted exposures are objectionable, as the effect is gained by using a very weak developer after an exposure of abnormal length. For contact printing, or for enlarging in a good light, and from suitable negatives, no objection need, perhaps, be raised, but in the dull light of the winter months this system of working is almost impossible. A correspondent, however, in another column this week, calls attention to another means by which the same end may pos- sibly be equally well attained without the same necessity for increasing the exposure ; indeed, speaking from recollection of the behaviour of the developer referred to by him, we believe the general tendency is to give the warm tones with a normal exposure, though, as in other forms of development, the effect increases proportionately with its extension. The means re- ferred to consist in substituting ferrous sulphite for ferrous oxalate, either partially or wholly, but preferably by making & mixed solution of the two salts. Mr. M. Carey Lea was the first, soon after his introduction of the ferrous-oxalate developer, to call attention to the de- veloping power of several of the other ferrous salts, and amongst those of which he spoke most favourably is the one in question, the sulphite, which, however, has not, up to the present time, been recognised as an established developing agent. It has. Jlarch 3, 18031 THE BUITISH JOURNAL OF PH0T0GRA.1'HY. 131 been put forwarrl, as our corrCKpondent points out, as a means of restoring the energy of a spent ferrous, oxalate solution, and it was in employing it in that connexion that we some years ago noticed its remarkable tendency in the direction of warm tones. This is more particularly the case with collodion emulsion plates, with which we have obtained images that could not be distinguished from the red chalk or "Bartolozzi" effects that have become popular for some classes of portraiture. With gelatine films tlie colour is not, as a rule, so decidedly rod, unless a considerably augmented exposure be given, but it is sufficiently removed from the ordinary ferrous-oxalate tone to deserve the title of " warm." The colour so produced is, moreover, jiarticularly well suited to toning either with gold or platinum, passing from the original red stage through the same range of purple shades as in the case of an albumen print. In fact, in this respect the toning is far more certain, and the final rtsult far more like an ordinary silver print, than when a chloride film is in question, and satisfactory tones can be obtained cither by transmitted or reflected light, that is, either for transparencies or paper prints. Ferrous sulphite is not itself soluble in water, though it is freely soluble in excess of sulphurous acid. It is also soluble — though probably by conversion first into oxalate — in oxalate of potash. It may be made by dissolving iron wire or filings in aqueous sulphurous acid, the result being a mixture of ferrous sulphite and hyposulphite, the former of which slowly crystal- lises from the solution or maybe precipitated by adding alcohol. A better plan, however, is to prepare it from freshly precipitated carbonate of iron, in which case it is obtained free from the hypo Balphite. The process is conducted as follows : — A concentrated solu- tion of ferrous sulphate is mixed with an equivalent proportion of carbonate of soda, also in solution, and the bulky, gelatinous precipitate — white at first, changing rapidly to dark green and eventually foxy red — is thrown on to a calico filter and left to drain with as little exposure to the atmosphere as possible The carbonate is extremely unstable, passing quickly, if exposed- to the air, into the state of ferric hydrate, when it assumes the characteristic brownish-red colour ; it is impossible to altogether avoid this change, but evei-y effort should be made to prevent it as far as possible by protecting the mass from the atmosphere It is hopeless to attempt to hasten the separation of the excess of water, ov to get the mass into a more condensed form ; all that can be done is to let as much water drain from it as will in a reasonable time. The next o{)eration is to convert the carbonate into sulphite. For this purjpose, if a very dilute solution is all that is required, let a given quantity of the aqueous sulphurous acid of commerce be shaken uj) with a quantity of the dirty green carbonate — rejecting, as far as possible, that which has changed to the red colour — until it will take up no more ; then let it settle, and decant the clear portion, or filter it. This, however, consti- tutes at best a solution of very low and indefinite strength, and the preferable, though more troublesome, plan is the best. Arrange an apparatus for the generation of sulphurous acid gas by fitting a cork to a wide-mouthed bottle or jar. Bore two holes in the cork, and into one fit a bent tube to lead off the gas, and into the other a funnel with a long stem to reach nearly to the bottom of the jar. What is known as a " thistle- head " funnel will answer, but it is better to use one with a Btop-cock, obtainable in all sizes at the philosophical apparatus dealers. Let the jar be three parts filled with saturated solution of sulphite, or, better, bisulphite of soda, insert the cork, and see that all the joints are tight. Place the precipitated carbonate in a wide-mouthed bottle, into which the bent tube from the generating jar is inserted, so as to reach nearly to the bottom. When this is all arranged, pour gradually into the generator, by means of the funnel, strong hydrochloric acid to decompose the sulphite. The acid must be added only a few drops at a time, as each addition will cause violent ebullition ; and here is where the utility of the stop-cock is found, as the funnel may be filled with acid, and a few drops allowed to trickle into the jar as the effervescence subsides, and without allowing the gas to escape except by way of the bent tube. The sulphurous acid, as it escapes, is taken up by the iron, and carbonic acid in turn is given off. Gradually the green colour of the carbonate changes to a dull brown, and eventually the liquid becomes clear, and then consists of a solution of ferrous sulphite in excess of sulphurous acid. Obviously it is of uncertain strength so far a,s regards the excess of acid, even though, with a definite quantity of iron to start with, the volume be made up to a certain quantity. But, if the passage of gas be arrested just before the solution becomes clear, a tolerable approximation can be made to uniformity in successive batches. The solution thus formed itself possesses developing power, but it is better used in conjunction with ferrous oxalate. By the addition of potassic oxalate alone, a developer of ferrous oxalate is formed, but the solution is not rich enough in iron to be advantageously employed ni this manner. Far better is it to mix it in definite proportions with ferrous oxalate de- veloper, made in the ordinary way, by which means a better idea can be formed of the actual constituents. Iiantem Slides as Window Secorations.— The lantern season will sooa be drawing to a close, but there is no reason why the slides should not still be objects of enjoyment by utilising them for decorative purposes. We were recently shown a frame of about a score of lantern transparencies, backed with ground glass. The frame was of lead, such as tliat used for church windows of stained glass, and the slides were surrounded by a narrow margin of various coloured glass. Strips of tinted glass, of quiet tones, were also interspersed between the photographs, which gave an exceedingly pleasing effect. With each transparency two nicks were cut in the lead, sometimes at the top, sometimes at the bottom, and at others at the sides so as not to weaken the frame generally. This enabled the lead, which is soft and ductile, to be turned back, so that any slide could be readily taken out and replaced by another as required. Ezcluslve Rig'hts. — Another exhibition in connexion with photography is projected at the Crystal Palace. The prospectus con- tains tlie following : — " Notice is hereby given, that the right of taking photographs in the Palace and grounds has been let by the Company under an agreement for a term of years, and all exhibitors are ex- pressly prohibited from taking photographs of any kind whatever. Any one invading thfise rights renders himself liable to a claim for damages." It is tolerably well known that Messrs. Negretti & Zambra have held this sole right for very many years— if we mistake not, from the first opening of the Palxce. The Company have, like the authorities at the Chicago Exhibition, often been censured for letting^ exclusive rights ; but it has no doubt been with them a consideration, as at Chicago, whether permitting the unlimited use of the camera would increase the returns to the same extent as letting the sole rights to a commercial firm. Improved Blood Albumen. — When an unusually mal- odorous sample of albumenis.^d paper is met with, v. is frequently 133 THE BRITISH JOURNAL OF PHOTOGRA.l'HY. [March ti, 1893 assumed that it is necessarily prepared with blood albumen. This is a fallacy, because blood albumen need have no more odour than that from eggs, while the latter may be, and often is, used in a most offensive condition. The application for a patent for tlie manufacture of a light-coloured albumen from blood has been made by a Dr. Carl Cosinera, of Berlin, the specification of which has just been issued. The inventor says, when deflbrinised blood is mixed with slightly acidified ethyl, or methyl, alcohol, or acetone, the albumen and the globuline contained in the blood are precipitated, while the colouring matter of the blood, hsematine, remains in solution. The method is briefly this : One part of defibrinised blood is introduced in a thin jet into four or five parts of ethyl alcohol of ninety-five per cent., previously acidified with one per cent, of sulphuric acid, the mixture being well stirred during the addition of the blood. Albumen separates in the form of almost colourless flakes, and the red-brown coloured mother liquors are separated by filtration. The albumen is then to be washed with alcohol, and afterwards with water. It can iifterwards, if desired, be bleached with any oxidising agents, such as hydrogen dioxide, &c. Considering the small proportion of albumen contained in blood and the price of alcohol, even methylated, we fear that photographers will not reap much advantage in their albumenised paper from the new process of obtaining albumen, however excellent it may be. Photogravure. — We have often in the past directed attention to the little interest taken by professional photographers in the various mechan'cal methods, photogravure in particular, also that work which could very profitably be done here was being sent abroad in large quantities for execution. Whatever the profession may have been doing, it is certain that of late many amateurs have been taking a great interest in photogravure, as evidenced by the large number who attended the two lectures by Mr. Denison. The process described by Mr. Denison is an exceedingly simple one, and will yield excellent results, requiring no expansive plant for its working. A copper-plati press, such as that used at the demonstration, costs but about ll'/., while a second-hand one maybe had for much less. A couple of pounds will cover the cost of the dusting-box, heater, "jigger," &c. The same heater that is used in the printing will also serve iu laying the ground on the copper plate. It will be better for the experimentalist, at first, to send his plates to a regular copper- plate printer to print, as skill is required in copper-plate printing as in all other work. Copper plates are not expensive ; the lialf-plate size cost from about two shilhngs to three shillings each, according to quality and finish, other sizes in proportion. Beginners in the work who are aufait with carbon printing will have far less to learn than those who are not, because the whole thing is dependent upon that process — the production of a carbon transparency, and from that a suitable carbon negative on the copper plate. The other portion of the work is very simple ; therefore experimentalists will, as a matter of economy, do well to master the details of carbon printing, and they are very easy, before essaying etching on the copper. If that be done, no ditficulty will be experienced in getting the most suitable carbon image for the purpose on the plate. THE WEAKNESS OF " STRONG POINTS." Although to some it mav at first sight seem that discussion respect- ing those so-called laws which have been formulated for the guidance of all who yearn to become art-perfect is outside the scope of a photographic periodical, nevertheless, as I shall presently sho-w, the particular one I wish to direct attention to is of unusual importance to all photographers, and I think my criticism of it will be welcome to a considerable number of the fraternity. The object of this paper is to remove from its high pedestal a cer- tain graven image which a large proportion of us have hitherto with confiding superstition worshipped, not merely to the exclusion of quite a host of other equally potent little idols, but also to the grievous neglect of the great mother goddess— Art. And the name of the graven image aforesaid is " Strong Points.' Wlio first set up this minor deity, so that it has come to be received as a major one, I wot not. Anyhow, Mr. Howard draws particular attention to it in his Skftcher's Manual, where, as far as photographers are concerned, it might have lain dormant until this very moment and longer, had not Mr. H. P. Robinson given it pro- minence and his own cachet by devoting a whole chapter of Picture- making by Photoi/raphj to its consideration. Ever since then the camera crowd has adopted and cherished this wonderful one rule as a sine-ipid-non in all pictorial designs. This has been much helped for- ward by the various handbooks of photography which, big and little, liave taken up the above now omnipotent law and enlarged upon it with untlaggiug satisfaction. It is so easy to demonstrate, so simple to master, so substantial to handle. Take a T-squave, divide your paper into nine equal rectangles, then where the vertical and horizontal lines intersect you have your "strong points;" upon one of these place your chief object. The recipe is more readily practicable than are the directions for boiling a potato. It is but a rhetorical exaggeration to say that from Abney's text-book, published ever so many years ago, down to Bothamley's shilling manual, which every one was last year reading, the advice upon line composition is mainly " strong points," leavened by a holy horror of that damnable lieresy " symmetry." All this widely disseminated literature, which is, as regards art matters, necfssarily founded upon opinions borrowed one from another, and all from one, has, in due course, borne fruit, which has nourished ii race of judges and critic-', who apply, as a kind of touch- stone, this magic principle of '• .strong points " to every luckless print, picture, or view coming under their ken. Is the main subject — say, the village church, or the toiling reaper — in or near the magic spot, the-n is ihe 2i*ns adnorinn safely got over; but, should the leading motive be palpably distant from one of the "strong points," then anathema! In vain may the landscape be brimful of sweetness, fancy, and delight, if it has sinned against this awful little law, it is only worthy of perdition — that is, perdition of medals. And so it must needs happen that " full many a time and oft," not the Ijest, but the second best, of two works is placed first. Far be it for me to deny that some one of the aforesaid points is- the strongest region in the rectangle of a picture, nor dispute that it is a good place to group the salient objects, because it is impossible to demonstrate the negative of a contention which only rests upon a fanciful impression — and, besides, I do not doubt but that in many instances some such a position is best for the purpose, for the sake of convenience, if for no other reason ; but what I most earnestly protest against is the growing habit of making this comparatively insignificant rule a chief test of artistic merit. I'o illustrate the immateriality of observing the law of "strong points," let me brieflv refer readers to one or two paintings which they may with ease inspect for themselves from the hands of artisst whom even photographers will not care to declare untrustworthy. First, an example of David Cox, whom we all know. In the South Kensington Museum is one of his master works, called a Water MUl in Wales. A most cursory glance at this (which is also reproduced in Redgrave's short memoir of the painter, and can be seen at most free libraries) will enable the student to note that it is composed in absolute defiance of the "strong jxiints" dogma. The most vivid juxtaposition of light and dark, the chief incident, the dominant forms, are arranged upon a vertical line, which, with almost mathe- matical precision, divides the picture into two equal parts! Next witness 1". Do Wint, whose Lim'oln Minuter (which can be seen iu the same gallery and the same book) is placed exactly central upon the paper, so that the bisection of diagonal straight lines occurs at the very acme of pictorial interest, which is therefore both vertically and horizontally equidistant from the sides. Turning to figure paintings, it is less necessary to advert to the ex- amples in which the model is placed on or by an upright central line, because the fault — if fault it be — is too common to need emphasising, but the localising of the centre of interest halfway between the top and bottom is less often done for the very suflicient reason tliat, inas- much as the head forms the kev, it is, as a rule, almost a physical im- possibility to get tlie aforesaid centre of interest very far from the upper boundary of the canvas. Of course it can, by the exercise of some ingenuity, be done, especially where the figures are small in comparison with the dimensions of the composition. Now, in spite of all inherent difiiculty and improbabihty, it cannot be gainsaid that quite a number of figure subjects might be cited having their leadiuL' and dominating emphasis, alike human and artistic, in the very middle of the picture. Indeed, in several instances the artist seeras to pur- posely and contemptuously flout that upstart idol " Strong Points." I have made no diligent search for examples of the above, but find plenty of them ready to hand ; of these I append one or two. Firstly, there is The Kim/s Daughter, by Herbert Schmalz, shown at the New Gallery in 1889, and reproduced in Pictures of the Year. published at the Palt Mall Gazette office. In this, although there does not seem any reason why such should be the case, the chief %uie March '-i, If 93 J THE BRITISH JOURNAL OF PHOTOGRAPHY. 13.-1 is not only midway between caoh side of the canvas, l)ut her face, which is liio essence of the painting, is over a point equidistant from ;ich corner. A-'ain, who is thero that, havinfr seen, can forjret Henrietta Ray's .ntrancing /fpht/run Wwnm/ Flora, which was in the Koyal Academy of 1888? Well, here we find that the two heads are nrranc;ed upon a central perpendicular line, and, moreover, a circh- of relatively smnll radius described about the centre of tlie picture will include the faces .if Flora and her swain. No Hseful purpose is served, or I would continue the list of works by eminent artists showinsr a complete disrof^ard of the tenet of " stronff points ; " but enough has been done to prove t hat the rule, " Put vour chief object in the corner," as if it were a naughty boy, is not by knv means an essential one, but i.s one of those unimportant regulations which, good in its way — as is, say, sea-bathing or smoking — maybe practised or not, at the pleasure of the artist, without detriment to his production. In conclusion, I hope my remarks will induce those who take upon themselves!, or have thrust upon them, the duty of passing judgment upon photographs to be in the future less prone to condemn a study simply because it does not conform to the greatlv overrated doctrine of " atrong points." Hector Maclean, F. G. S. SPECI.A.LISATION IN FIXE-ART WORK. [West Londou PhotORraphic Society.] The photographic world is a comparatively small one, and it needs only that a man should make a few pictures and contribute an article to the photographic press to ensure his being known to the average photographer; hence I may not be taking too much for granted if I presume that I and my misdeeds are not altogether unknown to at least some few of those who have courteously come here to receive me this evening. And, this being so, I am wondering what you expect of me. Your syllabus makes me responsible for a paper on " Art and Photography." How delightfully vague ; how good of your Secre- tary to give me such elbow-room ! I hav(( been presumptuous enough to suppose that ray works or my doings are not wholly unknown to you, and from this, and from the title which is put down for me, I imagine that you may perhaps share the general though somewhat erroneous notion that I am pledged to uphold the possibilities of photo- graphy in the lield of fine art, and may possibly be expecting rae to speak of such matters to-right — expecting me to once again enter the lists, to fling down the glove to you, and demand the homage of every artist to this fair sun-goddess, and compel your acknowledgment of her purely art claims, admitting her in all respects equal to those queens of the tournament, the pictorial arts, whose claims are already established and whose sovereignty is aclinowledged. " Fiddling on the same String." Now, ladies and gentlemen, 1 propose to do no such thing. I am by no means in fighting condition, and have grown wary of late how I enter into any such conSict as the championing of photography as an art might lead to. It is a considerable time ago that I accepted, with great pleasure, your President's invitation to come here to-night, and my memory may be at fault; but I believe I gave as the title for a brief discourse "Specialisation in Art "Work," and I did so with a deliberate in- tention. I was at that time smarting under a newspaper critique which described some of my own picture attempts as "fiddling upon the same string," which I considered as uncalled for as it was foolish (I hope the reviewer is here to-night). In the heat of the hour I felt eloquent, and partly for the sake of self-defence, and also because 1 felt that I might thereby drop some remark, some slight suggestion, which should be of use and of interest to others, I elected to read a paper on " Specialisation," which is, perhaps, a prettier expression for " fiddling on the same string." What a Picture should be. But, whilst I foresware any intention of urging upon you the high artistic position which I may or may not believe photography should hold, my remarks must apply essentially to that side of photography which, in order to avoid the debatable "term artistic, we will call the pictorial aspect of photography, meaning by that photography employed for the production of a complete and aesthetically pleasing result — a picture, not a diagram, or a mere refiection of objects or cir- cumstances— a picture, not a mere memorandum to be employed by the painter, artist, or draughtsman, in his subst^quent work — a thing of beauty, not a pictorial anecdote, nor an exhibition of execution, or a cleverness which may come of much careful training, but a picture which corresponds to the impresHion which any arrangement in nature left upon the artist's mind, and may be depended upon to awaken a resjwnse and a similar impression in the spectator to whom it may appeal. I trust I am making my meaning understood. I want so particularly to clearly express my own notion of what a picture should be, it would clear the way very much for those who claim that photography may be art. I don't say it is, at least not here ! Truth, to tell, I am trying to find out, it may be I shall bo following an iynis fatuus all my days, but it is a fascinating pursuit and a pleasant one, and, any way, it will keep rae from meddling with my brother photographer who makes topographical views and curiosities of manipulated skill his special care. Nature rarely Right Artistically. In the endeavour to produce by means of the ca.meTa, pietureK pro- perly so called, we must disregard every other consideration ; it is by no means sufficient that a photographic picture should lie an exact copy of nature, it must aim at Boinething more than that ; remember that, artistically, nature is very rarely right. You may remember who it is that has said, " To say to the painter that nature is to be taken as she is is to say to the player that he may sit on the key-board ;" and, again, " Nature contains the elements, in colour and form, of all pictures, as the key-board contains the notes of all music," and it is for the artist to select, to emphasise, to suppress the notes according to his fancy, and to group, to combine, and weave the whole into an harmonious chord. How is this to be done by photography ? Well, well, I am not here to say it can be done, I will not now say it ever will be fully done, but I may privately think sometimes that we are perhaps nearer the goal than we were. Please observe the " sometimes " and " perhaps." Am I not very cautious ? — too guarded, too doubting, I know, for many who, having secured with their camera a little impressive bit of landscape, very pleasant to look at, often full of suggestion, in feeling, in task*, in treatment so far above the typical photograph that, in a proud moment, they fancy the doors of the Temple of Art standing wide open to receive them. Examining and Studying Nature, So, now, if we are devoting our photography to the production of pictures, in the best sense of the word, it will be necessary for us to examine that nature which. lUce a keyboard, contains all those notes which we shall need to make our harmonious composition, and study them all the more closely because we find that the composition ready to hand is usually far from perfect ; and, liaving acquired an intimate knowledge of things around, we become more fastidious and less easy to please. I know of no more hopeful a sign in the photographer than the over-exacting and dissatisfied mood of the man who has been there before, and will visit that spot again and again, patient until this and that feature are in proper unison, waiting and watching so that the objectionable shall be I'emoved and the wished-for come to pass — perhaps, after all, to go empty away, because he found nature not wholly right. Dutifully and reverentially he hoped nature would come right — come as he wanted her — because he, lacking the painter's skill, could only photograph a little less than nature chose to show him. Herein is the barrier. Who will break it down ? Not enough Serious Study. This waiting, and watching, and patient study implies a seriousness of purpose which is all too rare amongst our photographers. With those who find in photography a pleasant pastime, an occupation for leisure hours, much that I have said must appear very unnecessary and making much ado about little. With such a one I have nothing to do for the present, and I can only presume to interest those wlio, like myself, care for photography, not for its own sake but merely as possible means to picture-making, and hence I make com- plaint that much photographic energy is misapplied. There is too much of the hobhy and not enough of the serious study : too often a holiday-making air about the excursion with the camera, a triviality of purpose and insignificance of aim. This cannot fail to make itself felt in the resulting works, and it is not fair to judge of what can possibly be done with pliotography by such examples. Lst me tell you that the man who goes out with his photographic appliances with the serious purpose of getting a picture which shall express some of the poetry and sentiment of nature, but returns home without having used a single plate, has done a better day's work than many who may have exposed the entire half-dozen here and there at each prompting of fancy and inclination. Still, there is hope — nature is not always so coy ; and, on the other hand, sometimes the photographer may do well to be a little less exacting, or at least be content with a compromise. ia4 THE BRITISH JOURNAL OF PHOTOGRAPHY. [March 3, 1893 If the photographer cannot gather and choose the elements of his composition as he wishes, still, if he accept, after diligent search, what is given him, the greater truthfulness with which he can portray this little may he some compensation for his limitations in another direction. Waiting for Natciib in the Mood we Desire. But let me attempt to come more precisely to the matter in hand. I have pointed to the necessity of finding nature in her hest mood. I don't mean necessarily in her most sunshiny and smiling mood, because, for my own part, I find nature weeping, or wild and stormy, more charming tlian in radiant sunshine. You know what Mr. Whistler says about " the sun blazing, the wind blowing from the east, the sky bereft of cloud, and without all is of iron. The windows of tlie Crystal Palace are seen from all points of London. Tlie holiday- maker rejoices in the glorious day, but ihc painter turns aside to shut his eyes." But it is necessary to wait until we find nature in the mood we desire, and this means many visits to the same spot, perhaps many plates exposed. If I could but drive home to each landscape- worker the desirability of often visiting the same spot, I should be ■well repaid for speaking. The facility with which a plate may be exposed, and something hke a satisfactorv picture obtained, is probably photography's greatest stumbling-block. If only we could sufficiently restrain our impetu- osity, and never expose the plate until we have become acquainted with every feature, every form in the scene, we should be surer of success, and we should probably be surprised to find that the effect which pleased us at first is far surpassed by the effect which we subsequently discovered. But our habit is to wander over yonder green bills to-day, and, not finding a subject to please us, to-morrow we traverse the woodlands, and next day the meadows, securing something perhaps from each. Ringing thb Changes on a Singlb Landscape. But surely it is hardly reasonable to suppose that, if we secured a fairly pleasing effect on the day we visited a certain favourable point, by returning and going again we may be able to improve. We can hardly suppose that nature was forewarned of our first coming, and prepared herself in her best guise for that ^jarticular moment. A lucky chance may favour us in that way sometimes, but I say that, if we bring away a charming picture of a given spot on our first or second visit, continued visiting and further observation will more probably result in something even past our highest conceptions. And, if this is true of a definite spot, so is it still more so of a certain class of scenery. I will say that within the limits of one small valley, on the slopes of a single mountain, by the banks of a river, between one lock and another, there is subject-matter for a life- time. Changing seasons, changing skies, and not until you have studied it all shall you know how much there is in it worth noting, or what effects are possible. I think it is a fair comparison tn ask that, suppose a scene to contain twenty matters of detail, twenty notes of form, light, shade, &c., will you tell me how many changes you can ring on twenty not^s in music ? And why not in our landscape ? And in the course of all this prolonged study we shall have ex- posed a great number of plates. a«^ every picture will be of much the same character, and we shall hear it said, " How long this fiddling on the same string?" What matters if at last our melody is more perfect — as it is sure.to be — than when for the first time we struck it ? Something to bb made out op the most Unattractive Subject. I do not know whether any of you have known what it is to have ac- quired a taste for a scene or for a certain description of landscape which before you had felt no particular liking for. Have you ever known what it is to pass through a district and be quite unmoved to admiration, but upon a subsequent visit to express surprise that you had not before noticed this or that picturesque possibility ? I have, and felt it very keenly, and then, yielding to inclination, have found that what I had previously regarded as a very unpromising district to be crammed full of beauties wholly unsuspected. I am convinced that most spots, carefully studied, will, after a while, have a very different aspect viewed pictorially ; and many of us might do worse than to sternly resolve to make something out of the most unattractive and unlikely material, making, in spite of first impressions, a picture where such seemed impossible. It would pro- bably be a more profitable occupation than running to and fro upon the earth and touring in far-off places. I am speaking artistically and pictorially, and make no reference to the pleasure of the thing. A Little Bit of Practice. Following all this theorising with a little bit of practice, I re- member that, within a period of seven days last spring, I exposed six plates on tlie same spot, each time believing that I had found the view in the best possible light and circumstances. At the side of a broad space of water was a little promontory of green grass and moss, perhaps some twenty feet in area, fringed around with tall reeds, at that time newly springing into greenest life, but which in summer would have shut out my view, marsh- marigold, and butter-burr sprinkled the ground with their glorious yellow flowers and jewelled the rugged grass — grass so soft and vielding tliat the feet sunk in the spongelike turf and made one wary of walking. On this little region of turf I spent whole days, and watched tiie particular s^enc in front of me from fifty different posi- tions, and, as I have said, exposed some six or seven plates, and, thougli none are bad, certainly the latter ones are better. Sti'.iy a Particular Class op Subject tiiohoughly. I cannot too strongly advocate confining attention, for a considerable time at least, to a particular class of subject, and learning thoroughly. Is it not what the painter does? He will study in one particular district for a long period, not becAuse he wishes to practise mere skill in copying, but because we cannot know the conditions under which various objects appear best until we have seen them under all. And, but that time will hardly admit, and I have not the present inclination to claim your patient hearing longer, I might advance as a reason why it is only by long watcliing that we may know what is best, that ultimate impressions are usually more lasting, and there- fore in better taste than immediate impressions. Things which im- prove upon acquaintance are generally more worthy our attachment, and, in these sensuous appeals, are more satisfying. The subtle and obscure, veiled, hidden away, hard to find, be it form or colour, possess a more enduring charm than the gay and glittering thing which quickly attracts but as quickly palls upon the senses. A. HORSLEY HiNTON. THEORIES OF DEVELOPMENT. [Photosraphio Society of Philadelphia.] I LISTENED with much pleasure and great interest to the lecture of Dr. Mitchell, delivered at the last meeting of this Society, and was especially gratified to find that some opinions of mine, held for some time, regarding development were supported by such an able and eloquent advocate. I refer principally to the building down or etching of the film of the dry plate in contradistinction to the building up in the wet plate by the application of the alkaline developer, which, to my mind, accounts partly for some of the mishaps that frequently occur to all of us. But I think it hardly fair that tue Doctor should so summarily have dismissed the photo- physical part of development, especially so in view of the lately very striking discoveries made in regard to light. I refer to its pro- duction of sound. It was found, so the report states, that when a beam of sunlight was thrown through a lens on a glass vessel con- taining lampblack, coloured silks, worsteds, and other substances, this beam of light being cut up by a rsvolving disc, so arranged with slits as to make alternate flashes of light and shadow, sound was heard, the ear being placed close to the glass vessel, as long as the flashing beam was falling on the vessel. By continued experiments a more wonderful result was obtained. A prism being interposed between the disc and the lens, it was found that sounds were given with different intensity by different parts of the spectrum, and at times no sound was heard in other parts of the same. The report goes on to say that when the red played on the green, or green upon the red, the sounds were the most intense of all, but when blue was used there was little or no sound given off. The published account of these experiments in the Art Journal are not as full or well arranged as one would wish, and we will anxiously await further developments. But from these experiments, if correct, it will be necessary to give to light other powers than have been conceded to it, and will considerably modify, if not change entirely, the theories of the formation of the latent image as now held. TUBBE ThEORIF.S OF DEVELOPMENT. It is well known that, in regard to the formation of the latent image and its subsequent development, there have been three classes of investigators and defenders, two of these classes holding very widely different views on the subject : — The photo-physical, who claim that the action of light by its dynamic force so arranges or disarranges, as the ca8«< maj' be, and so makes less stable, the molecules of silver held in the gelatine film as to enable the developer to bring forth and render visible the image unseen until action has taken place. March 3, 1893] THE BRITISH JOUKNAL OF PHOTOGRAPHY. 186 The photo-chemical, who claim that it ia a tolerably certain fact that iinilor the action of light the haloid of silver, the bromidi'st, chlorides, and iodides have a tendency more or less powerful to return to the metallic state, which tendency i3 promoted and made perma- nent by the action of developers which are always reducinf^ agents; that is", they are substances which are able to reduce the soluble salts of siverto the metal state. But will either of these two theories account satisfactorily for all the chanfjes that take place from the time of exposure to the fully developed plate ? The third class are in favour of a combination of the two classes, or claim a mechanical and chemical combination, and set forth thus: The dynamic action of the wave of light, setting free the invisible particles of silver in the granules which form the emulsion on the plate, and these nuclei of metal acting as centres upon which the chemical action may take effect ami proceed to the end. We know that some agents have the power of starting an action, and that others, though not able to start the act, have the power of continuing it and completing it. Another theory is that the development of a negative may be effected in one or two ways. First, the new compound may possess an attractive force. The action of light on sensitive compounds of silver tends to cause the formation of a substance capable of attracting the metal of which it is a salt when slowly deposited from a solution. This first deposit is capable of attracting more of the metal, and in this way an image is gradually built up. This is the theory of the physical development of the wet-collodion plate. If the theory of the dynamic power of light can be proved, it can also be used as a theory for the development of the dry plate. Secondly, the image may be the result of the reduction, more or less complete, to a more elementary state of the altered compound when treated with certain solutions, in which state it may have the same attractive power as before. This is the ratwmile of all alkaline development. "Actinic Force " axd ■' Dynamical'' and " Mkchanical " PowF-ns OF Light. But to return to the discoveries previously mentioned, and subse" quent ones following rapidly, as they will. If correct they will of necessity displace to a great extent, if not entirely, the vagueness that now surrounds the words "actinic force," "dynamical," and "me- chanical" powers of light — words that are too frequently used to conceal our ignorance or to impress upon the minds of others an erroneous estimate of our own wonderful knowledge. If a wave of light is capable of producing sound, it must have ponderance, a power to disturb an equilibrium, to disrupt and to separate, in fact, a dynamic power in many ways. By dynamic power we mean the power inherent in light to strike, to move, arrange, separate, congre- gate, disrupt, build up, or destroy any of the elementary substances, and in many cases their compounds upon which it acts. The very disturbances which these waves of light are subject to in passing from and through different media must of neces.sity cause the generation of an immense amount of energy, and when we call to mind the immense velocity of these waves of light, and their un- countable number, we cannot as yet estimate the force contained in a single ray, or the power it exercises upon any sensitive substance it impinges on. It has been repeatedly denied that light produces any separation of the elements in the formation of the invisible image, such as occurs wlien a visible image is formed by its action. But where is the proof for this assertion ? I have as yet been unable to find it, though I have sought for it diligently, and am forced to believe it to be the dictum of one, repeated by others as true. The fact is, that, surrounded by light, we have all the time been wandering in darkness. Cannot the occurrence of halation or solarisation be explained if we give due credit to the dynamic power of light, as defined ? By halation we mean not only the havoc it plays on a window in an interior, but also with a landscape, the foliage becoming blurred, losing its true tone value, and thus becoming both inartistic and unscientific. We have been taught that the reflection of light from the outside or back of the glass or transparent support is the cause, and to prevent it we must back the plate with some opaque substance in optical contact. This explanation and teaching is true, as far as it goes, with our rapid plates and films. But why do these returning rays exercise this power, and produce this effect, if they have not hammering force, so to speak, upon the already disturbed molecules of silver in the film ? Wubstneb's " Improvements " on the Sandkll Plate. A plate has recently been introduced in England, called the Sacdell plate, that is said to be entirely free from a chance of this mishap. It is coated by two or three emulsions of different sensitive- ness, and to my mind this tells the story. The first coat is decidedly less sensitive than the others ; in other words, the light power is used . up by the time it reaches the glass, and there is no reflection. The objections raised against those plates, in the main, consisted of the extreme length of exposure said to be necessary ; but even here " the doctors disagreed." Wuestner, of Jersey City, baa very much improved the Sandell plate. His first substratum was a slow ortho- chromatic, and upon that spread one or two emulsions of high and highest sensitiveness, working upon the premises that halation occurred less with dyed than plain plates. Since then he has al«f> prepared another brand, simply with plain bromide of silver emulsions of different degrees of sensitiveness. It is said that either of thew! plates works rapidly, and can be safely used for instantaneous exposures, and that halation has been reduced to nil. The reversal of the image is evidently caused by the same action of light as in halation, but that action has ceased before halation is produced. Foo. The veiling and the ultimate production of fog can be accounted for if we agree that the dynamic action of liglit causes the molecules of silver to be so arranged and freed from their environment in the gelatine film, so that the latent image is formed, and, by development, made visible. All goes well if there are plenty of molecules of silver for the developer to act on. But let the film be weak in especially the iodide of silver, we find at a certain point the developer stops its work. An additional quantity of the alkali is added, the work begins again, then stops. More alkali is added to force the developer. Suddenly a veil appear.-", followed quickly by a fog that destroys our work. \ou may ask me for my explanation of this destruction. The plates most subject to fog are those known as " rapid." The film is thin and very delicate. Bromide of silver is in excess, the iodide much less than normal. Whilst the light was so arranging the mole- cules of silver to form the latent image, it doubtless disarranged and partly separated some adjacent molecules, not needed for the image, from their weak support. The development censed because all the silver of the image was used up, or nearly so. More alkali, the accelerator, caused the using up of the remaining molecules. An additional dose of the alkali started the pyro or reducing agent in search for more material to work upon against the adjacent only partly protected molecules, and then — well — you all know what happens when a lighted match touches a pile of gun cotton. John H. Janeway, M.D., U.S. Army. THE PHOTOGEAPHIC SOCIETY'S LECTURES ON GRAVUEE." PHOTO- No. II. — Etching the Plate. On- Friday evening last Mr. Herbert Denison, of Leeds, delivered the second of two lectures on Fholoijranire, in 'connexion with the afiiliation scheme of the Photographic Society of Great Britain. There was again a very large attendance. Mr. J. Traill Taylor presided. Cleaning the Piate. After giving a brief resume of the previous lecture, which dealt with the preparation of the carbon negative or resist, Mr. Denison next treated of the copper plate for its reception. The plate, he said, should have a perfect surface, and be free from scratches. It should have bevelled edges, which avoid the risk of the plate being scratched in after bevelling. To clean it from grease, *c., which might cause irregular etching, lay the plate on a piece of clean paper larger than the plate, and rub the (ace with cotton wool moistened with a solution of American potash, strength immaterial. When the greasiness has disappeared, rinse the plate under the tap, and rub with another pledget of cotton wool moistened with nitric acid solu- tion— 1 ; 3 ; rinse again, and rub over with washed whiting moistened with a five per cent, solution of ammonia. Whiting for the purpose can be prepared by mixing ordinary whiting with water, decanting the solution after the coarser particles have settled, and allowing the finer particles to settle when the whiting is dried for use. The plate should have a final rinse in hot water, and be dried with a clean cloth. Latino tbs Qrocno. The bitumen ground is laid in a box, the size of which depends on the size of the plate. Through the bottom of the box wire nails are driven from the outside so that the points stick np inside and serve as a rest for the plate out of the way of the dust, which will lie at the bottom of the box. A piece of wire netting fixed at a convenient height answers the same purpose, or a little stand of two pieces of wood in the form of a cross. The inside of the box should be lined with glazed paper to prevent the adhesion of coarse particles. The plate is admitted through a door in the box, and the latter is suspended on pivots so as to be easily revolved. About half a pint of finely powdered bitumen is placed in the box, which is revolved about twenty times, when the plate is placed in I-'3« THE BRITISH JOURNAL OF PHOTOURAPHV. [March 3, 1893 position, and after from three to five minutes the plate is talien out. It will have a layer of bitumen in small particles. The more delicate the subject the finer the grain required ; a dark subject requires a coarse one. The quality of the grain can be varied by allowmg the dust ill the box to settle for a longer or shorter time, or by leaving the plate in the box a longer time, or by inserting it again. If the dust is allowed to settle for about two minutes, all the coarser particles will have subsided, and only the finest will remain in suspension ; so that, it the deposited dixtt is found to be insufficient, the operation can be repeated. For ordinary subjects Mr. Denison finds that the most suitable grain is obtained by allowing the dust to settle for from half to oue minute, and leaving the plate in the box for ten minutes. Fixing the Grouxd. This is done on a copper-plate heater — that is, a plate of iron about a quarter of an inch thick, and larger than the plate to be heated, placed on a suitable gas-stove. In a makeshift arrangement, a sheet of paper is placed under the copper plate, which is set on the heater and watched till the ground is seen to become transparent and afterwards to darken. The plate is allowed to cool spontaneously. If the plate has not been heated sufficiently, tlie ground will not be attached to it ; if too much, the particles of bitumen will run together. To find whether the ground is properly attached to the plate, a camel's-hair brush should be applied to a corner of it when cooled, and the plate examined with a glass. The exposed tissue, liaving been brought into contact with the plate under water and squeegeed down, is allowed to remain so for about ten minutes ; then immersed in water at 100°, the paper backing stripped and development carried on as previously described. The resist is dried with methylated spirit and water, the former being added until all the Water has been removed from the film. When dry the margin of the copper ia protected with black varnish, a line being first of all drawn round it with a draughtsman's ruling pen charged with black varnish ; the back of tlie plate and the edges are also varnished. The plate before etching should be kept in a cool room to avoid stripping or cracking of the film. Etching the Plate. The iron perchloride etching solutions to be employed are :^- No. 1. 4.5° Beaume's Scale, 47 per cent, of iron in the solution. 2. 40' 3. 38" 4. 35° 5. 27° 41 38 35 27 The stronger the solution theless penetrating power it has ; a solution at 45° wiU only penetrate the thinnest part of the film, one at 27° will penetiate any thickness. No. 1, therefore, will etch the deepest shadows. No. 2 the next thinnest portion of the film, and so on to No. 5, which penetrates the thickest or high lights of the picture. It requires some experience to decide for how long each solution should be allowed to work before the plate is transferred to the next weaker, but a good guide is to allow each solution to operate until the darkening of the copper ceases to spread to a thicker part of the film ; when this occurs, the plate should be transferred to the next solution. Tlie action of each solution after the first is cumulative. Tlie etching of the plate as a rule takes from eight to twelve minutes ; No. 1 solution taking one minute. No. 2 two. No. 3 about three. No. 4 two or tliree minutes, and No. 5 until the highest lights are discoloured, and from hall to a minute longer. It is advisable to use the solutions at, say, 70° Fahr. The iron solution is made by putting about 7 lbs, of solid perchloride into a large wide-mouth bottle and pouring boiling water on it sufficient to cover it ; the liquid is drawn off with a syphon, and will register between about 43 and 45 on Beaume's scale, a portion of it can be evaporated down to form No. 1 solution, and water added to obtain the other four strengths. If the resist has been printed on standard brown tissue to a depth only just sufficient to give detail in the shadows, no difficulty should be experienced in watching the darkening of the copper beneath. CLE.iXixo THE Plate. When etched, the plate is washed under the tap, and rubbed with the fingers until the film is removed. After drying, the varnish is removed from the margin and back with a pad of cotton wool moistened in benzole, which also takes away the ground. The plate ia next rubbed witli another pad of cotton wool, a small quantity of spirits of turpentine having been poured on the plate ; after drying, it is further cleaned with cotton wool moistened in methylated spirits and dried, the final polishing being given with the washed whiting and five per cent, solution of ammonia already spoken of. Tlie whiting being removed with dry cotton wool, the plate is ready for printing. Making Cokrections. A proof is next pulled to see what corrections are necessary. Portions of the high lights wliich have been edged too deeply may be reduced by burnishing with a steel burnisher, faults caused by spotting and pinholes filled in with an etching needle, and the light portions strengthened witli a roulette. If the plate has not been etched sufficiently, it may be re- etched, which is done by rolling up the plate with a gelatine roller using a special ink composed of Spermaceti 14 ounces. Stearine 6 J „ Asphaltum 2J „ White wax C ,, The asphaltum is first melted and the other ingredients added gradually. This is mixed with an equal quantity of lithographic ink and made thin enough for use with turpentme after rolling up, the plate is shghtly warmed and re-etched with an iron solution at 40'. During the evening Mr. Denison demonstrated the preparation of the copper plate, the development of the resist, and the etching of the plate, and introduced Mr. Eeardon, of Messrs. Brooker & Co., copper-plate printers of 78, Margaret-street, who printed from several plates. Steel Facing the Plate. At the conclusion of the lecture Mr. Denison described the method of steel facing a plate. It is as follows : — A wooden box has two brass rods running its whole length, and from them are suspended the copper plate and a plate of iron measuring one quarter of an inch, thick face to face. The solution in the trough is composed of one pound sal-ammoniac and one gallon of water. The electricity is supplied by a battery consisting of a stick of carbon in a porous cell, the latter being surrounded with a plate of zinc and the whole contained in an earthenware jar. In the outer cell is sulphuric acid solution 1 : 10, in the inner bichromate 3 : 20. The rod from which the iron plate is suspended is connected with the carbon anode tind that supporting the copper with the cathode. The current is allowed to pass through the trough for two days before being ready. The plate should be carefully cleaned before steel facing, first with turpentine and a nail brush, then with benzole and rinsed under the tap, and then put in caustic potash solution 1 : 10 for half an hour. It is further rubbed and cleaned alternately with nitric acid 1 : 20 and with whiting and water, the operation being repeated until the plate is chemically clean. A piece of copper wire is soldered on to the back, and by this the plate is attached to one of the brass rods opposite the plate of iron. A sufficiently thick coating will be obtained in about half an hour. The proceedings terminated with a vote of thanks to Mr. Denison, who, in acknowledgment of it, expressed his pleasure at the interest which had been taken in the lectures. MULTIPLE-COATED FILMS IN PRACTICE. The promptitude displayed by American dry-plate makers in placing multiple-coated films, primarily designed to resist halation, on the market so soon after the introduction in England by Messrs. B. W. Thomas & Co. of their double and tiiple-eoated plates, as well as the many interesting discussions to which the points involved have given rise, says much for the acumen of Mr. J. T. Sandell in devising and taking advantage of this system for curing one of the commonest defects to which negatives on single coated films are liable. It must be obvious to the photographer that, by the superposition of a rapid film upon a very slow one, both back reflections and lateral spreadings of the light rays are largely, if not entirely avoided, and as it is conceivable that these phenomena are present in most subjects, not counting difficult interiors, upon which the lens is brongjit to bear, the gain in vigour and brilliancy of image, in the proper separation of tone and the better and truer rendering of gradation by the use of plates having this semi-catalytic substratum, so to speak, should be highly welcomed by those who are alive to the influence of halation, which Mr. Sandell, with considerable show of reasoning, regards as an almost omnipresent evil, in flattening and degrading the image. Extending the same principle a step further, a triple-coated film designed for interior work, which both dispenses with backing and gives a long range of exposure latitude, thus rendering it virtually unpossible for the photographer to over-expose in this kind of work, should also prove a boon of great practical service. It is with these two objects in view that Messrs. Thomas and Mr. Sandell have been working ; but there is a third, which affects even the humblest and most incapable amateur. It is this : — That where the minimum normal exposure of the top film has not been under-estimated, the latitude in exposure (of course, to be followed by suitable develop- March !!, 18»3] THE BIUTISH JOURNAL OF PltOTGGUAPHY. 137 ment), is boundcJ by such widely separated limits tliat, for all praolicnl purpoees, one may,, by taking advantage of the imaf^e-forming properties of till' lower film, igiiuro, or rather clour off, the fo(!gud impression on the top lilm, with the hiipiiiest after-results, no far us the negative ia con- cerned ; or, where ho has sullicieut command over his developer, can produce a printable negative straight away. This, indeed, would appear to show tlial line can consistently over-expose with impunity with inultiple-coftted plates, without apprehending fatal consequences, and, within the limits spoken of, may be independent of exposure ealculations. As bearing upon the matter, we have lately, by the courtesy of Mr. J. T. Sandell. inspected a large number of 15 k 12 negatives, on Thomas's double and triple-coated plates, which that gentleman took during a recent visit to Italy and Switzerland. 'I'hc subjects chosen embraced Alpine views, and exteriors and interiors of liouiau, Venetian, and Milan churches, palaces, and monuments. The outdoor views were taken on the double- coated plates, and had a range of exposure of from a minimum of a quarter of a second to a maximum of many hundreds that length of time. In the Alpine views, the distance, which in all probability with an ordinary plate and an incorrect exposure would have been lost, was rendered with great force and strength; the exteriors of St. Mark's, Venice, St. Peter's, at Kome, two or three Venetian palazzi, the Doge's I'alace, and other subjects exhibit, not only an almost ideal preservation of crispness in the relative translation of tones throughout the scale, but also where marble was contrasted with darker stones, and where, as in the case of St. Mark's exterior, the elevation is adorned with frescoes, a most faithful rendering of the respective colour values. Mr. Sandell admittedly chose very difficult tests, and at the same time pitted himself against the best-known Continental photographers, several examples of whose work on the sairc subjects he also showed us, side by side with his own pictures. We must say that in the limited time at bis disposal, Mr. Sandell, by means of his multiple-coated plates, produced pure photographs of his subjects where the Continental photographers had falsified the tone renderings to an alarming extent. But Mr. Handell's success was undoubtedly the most striking in his interior exposures — particularly in the case of Milan Cathedral, which had five hours on a triple film. Commercial photographs of this subject are not to be had, ~o difficult is it regarded by photographers. Interiors of St. Peter's it Home, the Jesuit's Church at Venice, St. Mark's, St. John Lateran, md many others all taken on triple films, and with long exposures, appeared to us to show this class of work to a degree of excellence seldom met with, the absence of halation, the tone renderings, and the wealth of detail being remarkable. We understand that a public exhibition of prints from these and other negatiTes will shortly be given. THE STEREOSCOPE AND STEREOSC(;>PIC PHOTOGRAPHY. [Brixton nnd Cliipbam CaiuLTa Club.] Many authors in ancient and more recent times have observed and com- mented upon the fact that the image of any near object seen by one eye differs very considerably from that seen by the other, although no blurring is apparent when the same object is observed with both eyes, and several writers in the last century and in the early years of the present surmised -that it was to this that our impressions of the solidity and relative distance of near objects were principally due. Professor (afterwards Sir Charles) Wheatstone proved that this is the case by the invention, in IS.'JS, of the «tereoscope, which may be primarily described as an instrument by the means of which two dissimilar views of the same object may be simulta- neously presented one to each eye. Professor Wheatstone's stereoscope con- sisted of a long board, at each end of which pne of the two pictures was placed, one representing a solid object as it would be seen by the left eye, and the other the same object as it would be seen by the right eye. The pictures were placed in an upright position parallel to and facing each other, and midway between them were two plane mirrors adjusted so {.hat their backs formed an angle of ninety degrees with each other, and their fronts angles of forty-five degrees with the front edge of the board. The observer had to place his eyes as near as possible to the mirrors, the ,ieft eye before the left-hand mirror and the right eye before the right- baai mirror, and then adjust the position of the two pictures by means which were provided until similar points in the two rellected images osed to the action of a develop- ing or other agent, or any similar process be carried on which requires to lie performed in a non-actinic light, so that, by employment of the improved dish or case, which is made so that it is not affected by the chemicals used, any process of this nature may be carried on under inspection without the necessity of having recourse to a so-called "dark " room, or chamber, into which actinic light is not suffered to enter. The improved dish or case comprises an inner dish, preferably made rect- angidar, and consisting of a bottom and sides, the whole being made of gla.ss in one jiiece, and properly annealed. Near, or at one corner, is a projecting lip, open above, its upper edge being preferably about level with, or a little above the level of, the upper edges of the sides of the said inner dish. This lip or sjiout has free communication with the interior of the dish, and serves for receiving the developer, or other liquid which is poured into the dish, and for emptying the same therefrom. A vertical inner wall or screen, likewise of §l«ss, lies in front of the lip inside the dish, and extends from the floor of the ish up to a level with the side walls thereof, and from the side wall of the dish next to which the lip is made for some distance parallel with the wall on which the lip is made, extending past the lip, and terminating so as to leave a passage way between it and the wall for entrance or exit, of the liquid from or to the lip. This screen is intended to intercept the actinic rays of light which might eater at the lip. The whole inner dish may be made of ruby or other non-actinic K'la.ss (that is to say, glass which prevents ]iassage of actinic rays niule permitting of the jiassage of visual rays, or a certam quantity or amount e simnluneonsly with the descriptive matter accompanying it. In newspapers, periodicals, magazines, books, or any literary or artistic production of that class on any printing machine. In carrying out my invention, I coat a metallic plate, preferably a stereotype plate, with gelatine, so attached that it will not ultimately strip off; then sensitise it chemically, so as to become sensitive to light, and allow it to dry. When dry it is ready for exposure under a negative. After being sufficiently exposed to light it is developed in a bath of hot sulphate of iron, whiih has the property of shrinking those portions of the gelatine not acted upon by the light, hence its name of intagliotype, and leaving tho rest of the picture a rai.sed surface, without swelling the gelatine or softening it, thereby enabling it to be jirinted as soon as the plate is dry, which only takes a few minutes. The plate is then screwed on to a wooden base, the whole making a type-high block ready for the jirintcr. One of the features of the invention is the preparation of the negative so as to break it up in such manner as to protluce the effect of an engraving, and to enable it to print properly. This is effected by the use of thin sheets of transparent celluloid previously printed with the lines, dots, cross hatch or stipple, as may be required, and which ari^ jilaced before the negative in onJer to impart their characteristics to the ultimite plate. The best effects are pro duced by taking reverse negatives with different screens, the last one, with all the desired effects ui)on it, being the one used with the final sensitised plate. (For rough-and-ready work, the screens may be dispensed with altogether by the use of a plate previously embossed with fine dots, but the results are not nearly so effective as with the screens, by which any effect of a line engraving can be readily reproduced.) The invention applies to either method employed, the treatment of the plates being the same, though the resultant picture is entirely different. The great value of the invention lies in the fact that it is simple, rapid, and effective, there being no delay arising from the drjing of the gelatine, inasmuch as it does not require it, the action of the sulphate of iron not only shrinking it, but tanning it like leather, and enabling it to bear a prodigious pressure and print an incredible number of impressions without sensible deterioration. In its simplest form, it consists of the photographic representation of any picture in lines or stipple, in imitation of a line drawing or engraving where there are half-tones. The manipulation, when taking the negative, is the same as that of any ordinary photograph, and the finished negative requires simply to be placed upon the .sensitised film of the metallic plate, and exposed for a short time, to effect all that is necessary, the resultant picture not requiring to be touched by etching tool, graver, or acid, but simply screwed down to a wood block ready for the printing press. When the first negative is obtained, all that is necessary is to have at hand a few dry plates and transparent printed screens, developing solutions, dishes, &c., and a photographic printing frame. In order that the resultant picture may bo right-handed, like the original, reverse negatives must be )>rocurereaking the whole up into variegated grains of distinct characteristics, corresponding in appearance to an ordinary engraving. A metal plate, bearing on its surface a sensitised gelatine film, is placed under the negative last obtained, and both together exposed to light, natural or artificial, for the requisite time, which will depend on the strength of the light and the nature of the sensitised salts employed. After sufflcient ex- posure, the plate is immersed in a hot solution of suljdiate of iron, which shrinks those parts not acted on by the light, leaving the rest in relief, in addition to so hiirdeniiig the whole that, when it is dry, widch only takes a few minutes, it is quite ready for jirinting. The whole process is complete from start to finish in about an hour. The resulting block is remarkably durable, being far superior to other gelatine plates, owing to the developer causing shrinkage instead of, as in other processes, causing a swelling of the gelatine. The parts which are to receive the pressure of the printing press, so far from being softened, as would be the case if swelled, are converted into a tough, leathery substance by the double action of the sulphate of iron, which not only shrinks, but tans it at the same time. Its capacity to resist pressure without wearing or abrading is ajiparently due to the slight elasticity it still retains, but, at the same time, its hardness is .so great that it can be taken direct out of the bath and printed at once. The metallic plate employed as a basis for the gelatine film may be of any suitable metal, but stereotype metal is preferred, as not only cheap, ea.-ily ca-t and worked, but it readily forms a chemical combination with the acetic acid and gelatine. The stereotype plates are cast, varying from one-sixteenth to an eighth of an inch in thickness, according to size, the sizes chosen being those adopted by the photographic profession, and known as quarter-plate, halt-plate, cabinet, full-plate, &c., as the idea .all through the invention is to keep it within the scope of ordinary photographic manipulation for the sake of simplicity. It is easier to fall into these professional sizes, already in the market, than arbitrarily to fix others which might suit the printing trade better, for they %ill both have to work hand in-hand together, and, as both the metal plate and the negative have to go into the same printing frame, they should both be the same size. There is nothing, however, to prevent the printer cutting the plate smaller after it is finished, as the metal is almost as soft as lead. The idates may be cast on either a smooth or grained surface. If the former, they must be scraped, smoothed, and polished, or otherwise brought to a fine, even surface. These plates are reserved for the best work, and very varied and 140 THE BRITISH JOURNAL OF PHOlOGKAPHf. [March 3, 1893 beautifully artistic effects may be obtained from them, dtpendinp; entirely on the Tuaiiipulation of the negative. The grained or embossed plates arc for establislinients where rough-and-ready cheap production is of more moment than artistic refinement. The newspaper overseer, in a hurry to get to press, will find them invaluable when time is precious, and they are grained or embossed beforehand. The original negative is all that is required for these plates, nor is it neces- sary to use screens of any kind, because the pattern on the plate is partially reproduced by the gelatine film in contact with it. The operator, having pro- cured any ordinary negative, places it at once on his sensitised jilate, expo.ses it, dips it into a warm bath of sulphate of iron, and, as soon as the effects appear, withdraws it, screws it down on a wood block, and it is ready without any manipulation beyond mere handling, all the pronounced lines of the photograph come out distinct and clear, the halftones exhibit the pattern on the plate, and the whites, if not clear enough, can be readily cut away with a penknife. In the case of the polished plate, which is better adapted for book and pictorial illustration of the higher class, the assumption is tliat the operator desires the best artistic effect he can get, and. therefore, he takes pains to select his screens with discretion and judgment. With his first negative, he uses a screen with fine iiarallel lines in a perpendicuhir or diagonal direction, as he may think fit. Tliis results in a reverse negative, having all the charac- teristics of a positive, except that a thin white line appears throughout all the denser portions of it. He now introduces a dot or stipple, the purpose of which is to prevent the paper, when it comes to be printed, sinking down into the hollows, picking up the ink which may be lodged therein, and thus creating a smudge. These little jiin ]>oints, as they ultimately become, bear the paper off the hollows. With the la.st negative he inserts a screen of parallel lines in a horizontal direction, or diagonal lines at right angles to those of his first negative, and the effects he requires are produced on the final plate in a mixed cross-hatch and stipple. If he has any artistic feeling, and but a slight knowledge of retouching, he can obliterate lines or dots where he does not want them. As to the method of attaching the gelatine film to the metal jilate, a perfectly clean stereotype plate is made warm, and a warm solution of gelatine in glacial acetic acid is brushed over it in a thin layer. The acetic aoi'l, having a strong aflinity for the lead in the alloy of the stereotype metal, forms a close union with it, and, inasmuch as the solution of itself is a well-known adhesive cement, the union is perfect between them. Care must be taken not to mix too much acetic acid with the first coating of the gelatine, as the excess over what is taken up by the metal is liable to incori>orate itself with the next film flowed over it to render it so soluble that, when it undergoes final development, it has a tendency to crinkle in those portions not exposed to the light. The plate, being floated with a solution of good gelatine, well strained, is put away to dry in a ]ilace free from dust, yet where a current of dry air can get access to it. The film need only be thin, but it should be level and even over all the plate. The mode of preparing its surface to receive a photograph depends on the kind of light to which it is to be exposed. If for use with daylight or the electric light, it is simply sensitised in a bath of bichromate of potass con- taining a trace of bromide of ammonium. This soaks tlirough the film and chromes the acetate of lead previously formed below it. It is then allowed to dry, and kept from the light till required. The bichromate must not be so strong as to crystallise on the surface. To prevent this, it is a good plan to lay the jilates down on a level place and sensitise tliem by pouring a little of the solution upon the surface, rubbing it with the ' finger until the bichromate is absorbed by the gelatine, and finish off with a momentary wash in water. If neither daylight nor the electric light is available, a plate jirepared as described, but with the addition of chrome alum, and well washed, is coated (in place of the bichromate) with a sensitive silver salt emulsion, similar in character and composition to those employed in ordinary dry-jilate photo- grajihy. As this is a much more tender .and delicate film than the bichromate, great care must be taken with it at the early stages of the process. It is necessary to emjiloy chrome alum in the first coating of the plate to render it in.soUible. The acetic acid and gelatine have, therefore, a small quantity of chrome alum added to them with this object. The ingredients are all mixed together, made hot, and brushed over the stereotype plate, which has previ- ously received a wash of glaci.al acetic acid dried on. It is highly important, in the case of the silver enuilsiou, that not a trace of acetic acid be left on the jilate in a free state, as it would seriously interfere with the future develop- ment of the picture. At the .same time too much chrome alum must not be used, as it destroys the adhesive nature of the compound, and causes the film to strip off when dry. The proportions can only be ascertained by experience. as they vary with tlie kind of gelatine employed, strength of acid, &c. Of course with the silver emulsion process the same care nuist be taken to exclude all but non-actinic light as with a dry phate, the coating, drying, exposing, and developing being on all fours with other rapid photographic processes in vogue, the only difference being th.at, when the picture is taken and developed, it is not fixed in the usual way, but at once jilunged into warm sulphate of iron, and as soon as the gelatine has shrunk suftlciently, it is wiped with a cloth, mounted on a wood block, and sent to the printer. • Just as the electric light serves the jiurpose of workers in the bichromate process on dull days when daylight is not available, so the silver process can be utilised where the electric light is not available, and thus it becomes possible to carry on the work by any light, gaslight or candle-light ; in fact, the light of a match for a few seconds is ample for some reipiirements, everything in this particular depending on the sensitiveness of the salt emiiloyed. The invention is universal in its scope in this respect, and has the advantage that it can be carried on in the night contemporaneously with other journalistic work without the establishment, Avhere it is conducted, reqidring an expensive installation of the electric light, as has been necessitateil hitherto. In the matter of time, also, it is an immense advance on all other processes for the same purpose, it being possible, by using embossed plates and a silver film, to obtain a picture capable of being printed in the press within a quarter of an hour of its being taken from the negative, there being no occasion to use screens, or manipulate the negative in any way, the process being purely and entirely automatic. Where the best and most varied effects are desired, screens of transjiarent sheet celluloid, printed from engraved plates, must be used. They are cut the size of the plates, and may have any design upon them that fancy may dictate, but simple lines, hatches, dots, or stipples are all that is necessary. The claims are : — 1. The process of forming printing blocks, which consists in forming a gelatine photograph on the m.aterial of the block itself .and ex- posing it to the action of sulphate of iron solution, whereby the unacted upon parts are shrunk and the acted upon parts hardened, substantially as described. 2, A printing block formed of a metallic surface almost type high, and a hardened gelatine photograph taken on the surface itself, substantially as described. 3. The improvement in making photographic printing blocks, which consists in forming a fine stipple photographically all over by means of a finely stippled plate, substantially as and for the purposes described. Mtttim^ of SocttttCjS* MEETINGS OP SOCIETIES FOR NEXT WEEK. D^c March C. „ (5.. „ 6.. I, *>■ » *>.. „ 6.. „ 7.. 10.. 10.. 10.. 10.. 10.. 10.. 10.. 10,. 11.. Name of fiociety. Camera Club Dundee Amateur Peterboroug^h Richmond South London Stereoscopic Olnb Birmingham Photo. Society Bolton Photo. Society Brixton and OIai)ham Exeter Hackney Herefordshire Keighley anU District Lewos North London Oxford Photo. Society Paisley Rotherham Shetfield Photo. Society York Ipftwich Leicester and Leicestershire Leytonstone Muneter Photographic Club Southport Stockport Birkenhead Photo. Aaso Camera Clnb Cheltenham Glopsop Dale Hull London and Provincial Place of Meeting. Charing Cross-road, W.C. Asso. Studio, Netliergate, Dundee. Museum, Minster Precincts. Greyhound Hotel, Richmond. Hanover Hall. Hanover-park, S.B* Brooklands Hotel, Brooklands. Clnb Room, Colonnade Hotel. 10, Rnshton-street, Bolton. 376, Coldharbour-lane, Brixton. City Chambers, Gaudy-st,, Exeter. 206, Mare-street, Hackney. Mansion House, Hereford. Mechanics' luBtitute, North-street. Fitzroy Library, High-st., Lewes. Canonbury Tower, fslinerton, N. Society's Rooms, 136, High-street. 9, Gunze*street, Paisley. 5, Frederiek-ptreet, Rotherham. Masonic Hall, Surrey-street. Victoria Hall, (Toudramgate, York. Art Gallery, Ipswich. Mayor's Parlour, Old Town Hall. The Assembly Hoom.«, High-roiuT. School of Art, Nelson-place, Cork. Anderton's Hotel. Fleet-street.E.C. The Studio, 15, Cambridge-arcaile'. Mechanics' Institute, Stockport. Y.M.C.A., Grange-rd., Birkenhead. Charing Cross-road, W.C. 71, Prospect -str«et, Hull. Champion Hotel, 15, Aldersgate-st* North Rf'nt ! Gravesend. Oldltim I The Lyceum,,TJnion-sti'eet, Oldham. Bristol and West of England . Oaa-diff Croydon Microsoonical Halifax Ca,m»:ra Club Holborn Ireland Maidstone West Londcm , Hull „ Rooms, 28, Borkeley-sii., Bristol. Public HJall.Geor^'-street.Cl'oydon. Rnome, 15^ Daw son -street, Dublin. **-The P'aJace," Maidstone. Ohiswick School of Art. Chiawick. 71, Prospect-street, Hull. PHOTOCmAPHTC SOCIETY 0*' GREAT BRITAIN. FKBUf.vRy 28. — Technical Meeting, — Mr. Andrew Pringle (Vice-President) itt the chair. It was announced that, at a Council meeting held earlier in the same evening, Mr. H. C'hapnian Jones had been appointed Hon. Secretary, Mr. E. Cliftou Hon. Librarian, and Messrs. H. A. Lawrence and James Ciulott members of Council. ;Thk Gfa'Ie Hand Cameiu, &c. Mr. T. P.Watson exhibited and described the "tlenie" magazine hand camera of American design and manufacture, a feature of which is its compact ness. The magazine is of metal maile by machinery to gauge.s. takes twenty- four films, and the changing ia effected by a simjile " pull-out" nrrangenient. Mr. Watson also showed a simple catch arrangement for ]ireventing a second exposure on an Eastman roll-holder, the invention of Mr. Kawley, an amateur,, A PARAKFITS "BUN^^KX" BURNER. Mr. licon Wamerke exhibited a parattin gas-stove for lieating purposes, having the appearance of a Bunscn burner attached to an oil reservoir. It gives off as much heat as gas, and is worked by placing a few drops of spirit on tlie burner and lighting it. \Mion the parattin tlanie is alight, a lever pump^ increases the tiame to any desired intensity. One movement of the pump suffices for two liours. Tlie top part is made of non-fusible metal. Tlie burner has been introduced in R'lissia, selling at 15s., and Mr. Warnerke thinks il might be useful where a ffame for heating purposes is suddenly required and gas is not available. Acid Amidol. Mr. H. Chapman .Tones said there seemed to be an idea tlmt amidol for development required an alkali. The makers say that the small amount of alkali with tlie sulphite sufiices. There was, however, so little alkali present that he (Mr. Jone^) did not believe that it could have- any practical eftect. Byr Miirch 3, 189a] TIIR BHITISH JODRNAL OF PHOTOGRAPHY. 141 simply aciiUfviiiR with siilnlmroiis acid, ami giving nn exposure of one s«coii(l witli /-64, lie"li»il pro(lH«- tliat it was not the olkili wliii h was iiractically effeotive. Thr Pasoram. (.'olonel U. W. Stkwaiit, R.E., reail a pup. r on Panoi-amic P/io/onmphy- - Ihc I'anilane. The winder is controlleii by clockwork actuated by a ball and tube. A slit diaphragm is placotl between the second and third rollers. In use, the camera is set on its stand and levelled, the clock wounil up, the slit aperture adjusteil, and a suitable stop put in ; the camera is then turned round to ])oint to the li'ft hand of the view, the bulb squeezed, a needle holding the film in position withdrawn, ami the camera begins to rotate. I'rints of very great length may lie develo|>ed on the periphery of a drum. At the conclusion of the papor, Mr. ,1. A. Haubiso-n said the same principles were utilised in the Panoram as in the piiitiiscopic cameni, but in 1862 roUable tilnis were not available for the purpose. He exhibited an old revolving camera which was actuated by hydraulic iiower. The Chairman (Mr. J. Traill Taylor, who was moved to the chair after Mr. Pringle and the President had successively vacated it) said he had in his possfssicin a iianoramic picture of Red Lion-sipiare which, with a microscopic object-gl.ass of one inch ])OWer. revealed details that were invisible to the naked eye. Many years ago Rawlinson, of Windermere, sent him a pano- ramic view subtending the whole circle and about ten degrees more. Mr. W. E. Debesham understood Colonel Stewart to pro|>osethat panoramic pers])ective was in itself truer than plane perspective. This was a mistake. I'anoramic perspective would give views which could not be got in another way, therefore, whatever its faults, it came in useful for such views. Panoramic perspective is in itself false when the panorama is on a tlat jilane. No one could look at Mercator's projection without being struck at the extraordinary disparity in the si/.e which Greenland bears to the tropical countries. As to the perspective being true if represented on a spliere like the eyeball, it was not so. If the photograph was seen on Hat surface the only perspective which can give it truly is that of a flat-surface plate. If the photograph is that of a straight row of houses in cylindrical perspective, the eft'ect is that of the outside of a rotunda. The plane of the plate is the same as that of the picture at which we look. As to the distortion of the foreground, as compared with the bacl:- gronnd, and the middle distiMice, not occurring in jianoramic photography, the difference was between the margins and the centre. As to wliat Colonel Stewart had called distoition at angles of 80° and less, he (Mr. Debenham) thought he was mistaken. In wide angle pictures this Was the only perspective which would give the truc'rel.ation of the various parts ; he did not think it should be called distortion at all. The Chairman said a picture subtending an angle of 80° on the base line with a wide-angle lens is vety false in perspective. By photographing a row of spherical b.alls the centre ones would appear round, but as they approached to the margin they would be seen to expand laterally. They should be examined from a jioint of view equal to the focus of the lens. In a cylindrical picture the eye should be placed in a similar way and the picture looked at close, and then it would all be perfectly truthful. Both perspectives were wrong unless tlie pictnres were looked at proiierly. Mr. T. Samiels said the capacity of the panoramic camera was limited because its initial position must be level. At the same time such jdeasing pictures couM not be got with the ordinary camera. He had seen deptli on these pictures whicli he attributed to the lens being so well shaded from the light. He suggested modifying the diaphragm slit so thai dilferential exposures might be given where dark buildings, kc , came in. After some remarks by Messrs. Waruerke, Gotz, and T. S. Davis, Colonel Stewart replied to the discussion, and a vote of thanks was passed to him for his paper. North London Photographic Society.— February 21, Lantern Night, Mr. J. Brewer in the chair.— .Slides were contributed by Messrs. Healy, Williams, Clarke, and others. The set of sli.les entitled Places to l>e Visited by the 1893 t'onvention were shown. They were disappointing, and are far from doing justice either to the Devon and Cornwall Ciniera Club or the Devon and Corn- wall district. Next meeting, March 7, when Mr. A. E. Smith will demonstrate the photo-lithographic proce.ss. Hackney Photographic Society.— February 21, Mr. .1. 0. Grant in the chair. — Messrs. Sodeau and Nunri showed reductions by flashlight and print- ing-out lantern plate. Mr. R. Beckett showed a lens made from two ninepenny meniscus sjiectiicle lenses, and a portrait taken with it at full aperture, /-8. The Hon. Skcrktarv askeIates in common use when the lens is central, and also when the front was raised. Angle of view was next dealt with. It was pointed out that i»hot.'jgraphic plates being ma^le rect- angular, a portion of the plate or jjart of the .ingle of view (covering power> must be sacrificed. Where the latter course was adopteosition of the Society was held on Friday evening, February 24, in Queen-street Hall. The Vick'-Presidknt (.Vlr. J. C." Oliphant) in opening, said he desired to call the attention of this large meeting, many of whom must necessarily be still out of the pale of membership, to some of its benefits. The Society had an extensive membership, perhaps the largest of any similar body iu tlie kingdom, and in earlier years it took one of the foremost positions in Britain. By some una<'countable laxity they had recently fallen into a .slumbering state, a state from which the present Council wisheil to remove it. They had now secured good premises in Cistle-street, where, for the use of the active members, they had an excellent dark room, with all its applianc OS ; a large hall for ordinary meetings, as well as committee rooms ; the nucleus of a photographic library, as well as all the conveniences of a club. They wished still further to increase these benefits, their numbers, and consequent usefulness. For amateurs, now that a great many of the risks and diflioulties connected with the lantern and limelight were done away with, there was a wide field of usefulness, and the opportunity for a display of their work, besides that assistance derived from fcllow-meml)ership. All this only costs the active member ten shillings a year, leaving still the old subscription to those who did not wish to take full advantage of the bcneHts he had pointed out. This evening they were to have a selection irom a large number of the recent works of the members, which would now be shown upon the screen. The pictures exhibited were all by members, including Messrs. Mitchell (of Dalkeith), J. S. Smith, ,1. Patrick Reid (of Wishaw), and many others, most of which were of the highest class. The portrait figure subjjcts were probibly the least successful, but the landscapes, English cottage scenes, architectural work, interior and exterior, from Torquay to the north Highlands, were markedly fine. Those which comprised hgures with animals, from lions^and elephants and all those of the domestic type, were especially good. Sevcr.il excellent songs, with music, were much appreciated and applaudeil. The lantern work was perfect, save where an occasional hitch between the speaker's descriptive notes and the pictures shown did not h.armonise with each other. Mr. Oliphant called for an expression of thanks to their musical friends, who had .so well aided them. This was haartily given, and the meeting dispersed. Othkr Photographic Soc'ikties Pi,ea.sk Copy.— Mr. R. E. Fcnner-Kidson, the Hon. Secretary of the Brixton and Clapham Camera Club, writes ; " If I might, 1 shoulil like to call yourattention to tne fact that the pai>er recently read before our Club by Mr. .J. A. Butler on Stereoscopic Photoi/rnphi/, that by Mr. B. E. Piniler on "the Optiod Lantern, and that by Mr. W. Thomas on the Hand Camera (which have occujjied the members for the last three meetings, and of which I think any club might lie proud), have all been by members of the Club, the Committee having felt that in ordinary clubs of the type of our own there has been a tendency of late to rely upon outside aid for their meet- ings, instead of encouraging their own mambers to provide the entertainment." 142 THE BRITISH JOURNAL OF PHOTOGRA.PHY. [March 3, 1893 FORTHCOMING EXHIBITIONS. March 3, 4 *Blackheath Camera Club. Hon. Secretary, C. W. Piper, 46, Shooter's Hill-road, Blackheath, S.E. ,, 22, 23 Leice,ster and Leicestershire Photographic Society, Co, operative Hall, High-street, Leicester. Hon. Secretary- H. M. Porritt, 66, London-road, Leicester. April 5-8 *Croydon Camera Club, Braithwaite Hall, Wellesley- road, Croydon. Hon. Secretary, G. R. White, 55, Albert-road, Croydon. „ 12-15 *Bolton Photographic Society. Hon. Secretary, J. E. Austwick, 10, Rnshton-street, Bolton. ,, 17-29 'Photographic Society of Philadelphia. Hon. Secretary, R. S. Redlield, 1601, Callowhill-street, Philadelphia, U.S.A. May 4-6 'Forfarshire Photographic Association. Hon. Secretary, W. J. Anckorn, West Port, Arbroath, N. B. * Signifies that there are open classes. < ©orrejSiJonlr^nce, ' Ccrrcspondtntsi should never vrritc on both sides of the paper. No notice is taken of communications unless the names and addreBsca of the uriters are gioen. ANGLE OF VIEW. To the Editor. Sir, — " Free Lance's " pet sin seems to be disregard of the ninth com- mandment. In reference to my paper on Mr. Haddon's article in this year's Alman.^ck, he states that I endeavoured complacently to show the absurdity of the quoted table. On the contrary, I distinctly stated in the first paragraph that by correcting the rules I hoped to make the table valuable. " Free Dance " also states that my concrete example is a false one, because Mr. Haddon referred to a plate and not a negative or view. But I think Mr. Haddon's remarks, reported on page 91 of your Journal, show that this was not his intention, for he says : — " It is absurd to give a picture a fictitious value on account of a few trees, or twigs, or rocks at a corner, and so dignify it with an angle of 52° instead of, say, 42°." " Free Lance " recommends photographers to keep to the rules as stated. Let us examine what the result may be. A photographer wishes to use a 12 X 10 plate for a view and decides to include an angle of 62°. By Mr. Haddon's rule he will employ a lens of ten inches focus. If the lens only covers 62°, the corners of the plate, when developed and fixed, will be bare glass, if he uses another lens of the same focus, which will ■cover the plate, it must be of wider angle, or about 72°. Consequently the angle included on the plate is more than 62°. Instead of half the length, half the diagonal of the plate should have been taken as the basis of calculation, it the lens is used centrally. Had *' Free Lance " been less concerned with standing on his head, he would not have forgo ten to take the cap off the lens, and would have discovered his mistake. Cameras are provided with cross fronts and swing backs, and photo- graphers make use of these conveniences. Under either condition the centre of vision is moved. If a photographer wishes to make a picture under a given angle, it is for special reasons, one such being that the perspective shall not be too violent in appearance. A rule to be of value should be correct, therefore I hold that the calculations for the purposes named should be based upon the distance from the centre of vision to the •extreme limit of the plate. — I am, yours, &c., Philip Evebiti. 88, Evering-road, London, N., February 25, 1893. WASHING CUT FILMS— BLISTERS. To the Editor. Sir, — Allow me to thank yon and your correspondents, Mr. J. E. Hodd and Dr. J. Carter Browne, for their kind answers to my inquiries as pub- lished in your most valuable Journal. I will try the suggestion for washing films, but I am afraid that for 12 x 10 plates the suction will not hold, especially when the washing water falls edgeways on the plate. I have used the following way, which I think very good. I drill on the smallest edge two small holes with a drill, and hang up the films to a oross wire over top of washing tank with an S-shaped wire of suitable length, and then let the water run. This may prove useful to other users of the films, and if the manufacturers of films could drill the holes before- liand so much the better. Next I will answer in regard to blisters. Having used, since I wrote to jou, pure alcohol and not the methylated stuff, I find I am always iiaving the same trouble of scum after mounting, but iw blisters. I am not positive of it as yet, but I think this scum comes simply from the tint with which the albumen'paper is covered — pink, mauve, or whatever it is — being dissolved by the alcohol unevenly, and remaining on top through all ultimate washings without hurting it, otherwise than when dry. I will *ry white paper and then see the results. As regards blisters and a warm hypo bath I must say that I cannot agree with Dr. J. C. Browne, having tried long ago hypo at any degree of heat, from 40° to perhaps 100' Fahr., and have generally found the higher the temperature the more blisters and the larger ones. Alcohol I have found the only sure remedy. Nevertheless, I am very much obliged to these gentlemen for their kind suggestions. — I am, yours, &c., 4, Avenue Pinel, AsnUres, Seine, February 25, 1893. Albert Levy. A QUESTION BOOK. To the Editor. Sir, — At a meeting of our Council, it was proposed that a question book be kept. I suggested that any photographic questions that could not be answered forthwith should be banded in to me, and I would eater them in the aforesaid vc^ume, which Xvould be placed on thd table, and the query replied to by some of our abler members, such answers to be dis- cussed at a future meeting, and the best entered opposite to the propo- sition. In due course, a compendium of useful information would result. My purpose for encroaching upon your space is to see if other societies would take up the matter, so that at a subsequent date a temporary interchange of these records could be made. — I am, yours, &o., Fred. W. I'ilmtch, Hon. Secretary, Aston Photographic Society. Burlington Hall, High-street, Aston. A CORRECTION— FERROUS SULPHITE. To the Editor. Sin, — In my communication which you were good enough to publish last week, occurs a slight error, which has the effect of reversmg my meaning. In the last paragraph but one I say, " I have been unable to get the clearest and best 'gratings,'" &c., whereas I meant to say, "I have been able," or just the opposite. Some considerable time ago ferrous sulphite was recommended tor re- storing the ferrous oxalate developer when oxidised, or for keeping it in working order. I tried the method at the time, following the ins:ruc- tions then given, but cannot now refer back to them. I remember that I obtained some remarkably warm tones in development when using the sulphite, and should be glad to try it agaiu for the express purpose of utilising the tone, if you could kindly give me details o£ how to prepay the ferrous sulphite, which I find is not an ordinary article of commerce. Apologising for the trouble, and thanking you in anticipation, — I am, yours, itc, W. Lindsay. February 27, 1893. [See an article in another column on the subject. — Ed.] PHOTOGRAPHING HORSES. To' the Editor. Silt,— Referring to article on " Photographing Horses " in your issue of the 17th, I send by same post a few specimens of equine photography. The cart-horses were " handled " for the taking by Mr. G. M. Sexton, auctioneer to the principal horse societies, and I need scarcely say that it was an education to me to see and work for him. I prefer when taking horses, whether with a mount or not, to stand a little in advance of them, as it is then more easy to show the light between the legs, and I always expose with sky-shade instead of cap, that I may be able to keep my eyes on the animal. — I am, yours, &c., Tuos. Stokoe. Clare, Suffolk, February 27, 1893. RAPID SOLUTION MAKING. To the Editor. Sir, — It is awfully amusing to see old and tried friends of the photo- graphic dark room ("Lab." some people designate it now) popping up again under new parentage. The attention of Messrs. Baird, Ayres, and Webster has been drawn to the Doulton dipping jar, which has been in long use by the firm of Messrs. Martm & Co., and others. It has been long known to chemists and photographers (and especially to the chemist) as a most useful and indispensable article. The writer has used the following rapid solution appliance from wet- collodion days to the present time. It is exceedingly simple, and is in some respects an improvement upon Messrs. Martin's plan. It is this : — Procure a small, round, fancy wicker-basket, from four inches diameter to any depth or size, costing sixpence each upwards. Cover the outside of basket with thin calico, permanently fixed. For use, simply fill the basket with the crystals to be dissolved, and suspend it in the jug or jar, filling up whichever utensil is used with water. It is surprising how long these baskets will last, especially if rinsed under the tap after use to re- move sediment and impurities. Maich ;i, 18»;i] THE BRITISH JOUKNAL OF PHOTOGaAPHY. 143 Of course, 8s in tlio " old days," the Bame care is paramount in the " new times," separate bssketa must be used for different crystalH. But in the wet-plate days (nith certain exceptions), hypo and protosulphate of iron were used in large quantities, only two or three baskets were re aad 5i> groiiplenses, and 3b (Dallmeyer's). — Address, Lob8I>ai.K. & Co., 45, etrond Green-road, .N. antftocrss to (ffotresponTientB. %* All mailers intended for the text portion of this Journal, incltidiny queries and Exchanges, must he addressed to " The EorrOR, Thk British Journal of Photoghapht," 2, York-street, Covent Garden, London. In- attention to this ensures delay. *,* Correspondents are informed that toe cannot undertake to answer com- munications through the post. *,* Communications relating to Adtrrtisements and general business affairs should be aildressed to Messrs. Henrt Greenwood k Co., 2, Yorkslreetf. Covent Garden, London. J. J. — Apply to a photographic dealer. G. G. — Received and noted. 0 teinpora, &c. Ink Stains ; J. Brian ; and others.— In our next Derf. — We do not see any objection to your inscribing the cards as yom suggest J. Gould.— The new chemical formula; are given in the 1883 edition of Hardwich. M. A. R.— Ordiniiry silver prints placed together cannot be u«d for stereo- scopic purposes. E. Edwards. — Received. While the case is still pending, it would be improper for us to publish your letter. W. H. Wallace.— The camera and lenses named are excellent We do not recommend particular makes. Photomrter wishes to know the maker of a printing-out bromide paper for testing the actinic value of the light. A. L. S.— Consult the advertisements in the Almanac, where you will find descriptions of sets of apparatus at all prices. Peter.— Schlippe's salt is not much use[anac. Being soft and brittle, it is easily abraded by rubbing with the ball of the finger, and then it forms a good medium for retouching upon. By the way, " wlute hard varnish " is a very indefinite article, and varies with every maker. Samlarac is its recognised basis, but ■in many of the commercial articles common resin predominates. (Papier. — If the wooden vessel were lined with gutta percha there would be no advantage in coating the guttapercha with paraffin, which, by-the-by, would not be easy of apjilication. Either material by itself would answer perfectly. We, as a matter of economy, should prefer the paraffin. It will have no in- 7 .iurious action on the silver solution, and some say that gutta percha has. 'Certainly some .samples of the conmion commercial article does quickly deteriorate a silver bath for the collodion process, and the pure article is not easily olitainable nowadays. ?enC8 and with the .iss-istance of a sulphite even if acid, possess developing power. IIow fur the vastly greater reducing action of sodium hypo- sulphite will work in with amidol to make it really the most energetic developer extant remains ye; to be seen, but from what I have observed already amidol seems to offer a far better look-out than pyro, and to work in a more cleanly manner than the latter in the combination. W. B. Bolton. lr,o THE BRITISH JOURNAL OF PHOTOGRAPHY. [March 10, 1893 ON THE TONING OF SOLIO PAPER. [Photographic Club.] I HAVB thought that, instead of givingr you a paper on the combined toning and fixing, it would be preferable to give you a few hints on the general toning of Solio paper, in the manufacture of which I am personally interested. . . We have now arrived at that point where the new printmg-out paper is no longer in the experimental stage. It is largely used by the best photographers, both here and in America, and all speak in ■glowing terms of its superiority over albumen. This dear old friend ■albumen has had its death-bell tolled many a time before— certainly St has been the case every year durin" the la-t ten years— and yet it has ■ Hingered on, dying hard at the last. 1 think every one must see around 1ihe"m that albumen is giving place not only to the new pnnting-out papers, which must resemble it in appearance, but also to platinotype, bromide, and kindred processes. As this is to be a practical paper, I do not intend to dwell too much upon the pros and cons of the prossss. With this paper we have the greatest range of tones that the most fastidious can desire. Of coursBj^as with albumen, it is of the first importance to have a good negative. Having secured this, it is easy to secure a good print ; but there is no doubt that with the new printing-out paper there is a •far greater range to be obtained than with any other process. We have also at our command the capability of giving to our prints either a glazed or dead matt appearance with but very little trouble. On the question of permanency, there can be no doubt there is a igreater chance of achieving this than with albumen, which we all know is so liable to go wrong ; but to attain this, as with all photo- graphic manipulations, it is necessary that due care be exercised with tbe various stages through which the print has of necessity to go. To say that a Solio print is absolutely permanent would be taking a great responsibility upon myself, for in this mortal world of ours any- thing on paper could not be so; however, I will say we can obtain a reasonably permanent result. The fading of prints is, I believe, more often caused through unsuitable mounts and bad mountants than through any inherent defects in the prints themselves. As with all new processes, it is necessary that we take some trouble to understand the little peculiarities incidental to its working ; and, when these are once mastered, you will be surprised at the simplicity of the whole thing. In the printing paper before us we have chloride of silver, in conjunction with a definite organic salt of silver, held in suspension in a vehicle composed mainly of gelatine, and this is coated on a paper with a baryta surface, which prevents itsinking into the fibres of the paper, and we have a more brilliant print, and the elimination of the hypo is more easily effected. To get even prints, and to prevent uneven toning, it is ' absolutely necessary that the paper should not be allowed to become damp before printing, and, when separate toning and fixing baths are employed, careshould be taken that the hands are not contaminated with hypo during the preliminary washing and toning, otherwise red stains will inevitably be the result. As this paper is peculiarly susceptible to a diffused light, great care should be exercised in handling it in a very subdued light, both before insertion in the printing frame and during examination of the print, otherwise the high lights and purity of the resulting picture will soon be destroyed. It is not necessary to carry the prints to such a depth in printing as is the custom with albu menised paper, as the loss is not so great in the subsequent toning and fixing. Now we come to the all-important question of toning. What bath shall we use ? I think the first to engage our attention is the com- bined toning and fixing, about which there is such a divided opinion as to the permanency of the prints produced from it. There certainly is a distinct charm in the use of a combined toning and fixing bath, especially as no previous washing is required, the prints being taken direct f^m the printing frames and immersed in the one solution. There are amateurs who do not, and will not, use separate fixing and toning baths when there is one to be had that will do everything that is required in one bath. As long as too many prints are not toned in one bath, there is no danger of less permanency than with any other bath ; but, if the gold is exhausted, the toning proceeds with the lead, and probably sulphur also, in which case the prints may possibly change, but I do not think they would fade. The chances are they may become darker, especially should there be any sulphur in the atmosphere, and I fancy there is a good deal in London. This will probably attack the lead, and form sulphide of lead. Tlie opinion of any chemist here to-night on this matter would oblige. 1 have prints here which have been standing about on the mantelpiece of my sitting-room for over six months, and show no signs whatever of any change. The formula recommended by the Eastman Company is as follows: — Stock Solution No, 1. Hypo 6 ounces. Potash alum 1^ „ Sodium sulphate (Glauber's salts) 4 „ Water, make up to 60 „ First dissolve the hypo and alum in the water, then add the sodium sulphate. Stock Solution No. 2. Gold chloride 15 grains. Acetate of lead (sugar of lead) 50 „ Water 7J ounces. Note. — An orange precipitate is formed in No. 2 solution, which, however, redissolves on its being added to the No. 1 solution. To form a combined bath take of — Stock solution No. 1 8 ounces. Stock solution No. 2 1 ounce. Do not use until the mixture has become quite clear. In all solutions composed of hypo and alum it will be found that there is always a slight white precipitate. This, however, does not interfere with toning. This bath is very useful indeed for giving soft prints from hard negatives. It is not advisable to attempt to produce purple or black tones with this bath. For those who prefer a separate toning and fixing bath, and one that will produce warm black tones, there is nothing better than the sulphocyanide bath. In order to have this bath under greater control, the addition of acetate of soda is of very great advantage ; not only does it slow down the toning action, but the prints are not so liable to take that very objectionable blue surface tint which sulphocyanide, per se, is so apt to produce ; the tones of the prints can be more closely watched. Where, possible, it is certainly better to tone by daylight rather than by artificial, as with the latter it is far more difficult to watch the various changes of tone. Of course it must be done in very subdued light. As I said before, no hypo must come anywhere near the prints during the toning, otherwise the prints will be irretrievably ruined with red stains that will refuse to tone. Owing to the softening action of sulpho-cyanide on the prints, they should be washed in two changes of water, and then passed through a bath of alum water (alum half an ounce, water twenty ounces). After this they should be well washed in three changes of water, and then placed in the toning bath, as follows : — Stock Solution A. Sodium acetate 600 grains. Water 20 ounces. Gold chloride 15 grains. Stock Solution B. Ammonia sulphocyanide 50 grains. Water 20 ounces. For use, take of A two ounces, B two ounces, water four ounces. Allow to stand one hour before using. The toning may be stopped at any stage by immersion in a bath of salt : — Common salt 1 ounce. Water 32 ounces. For securing still greater control and regularity of toning, it is advantageous to use two-thirds of an old batn and one-third of a new one, omitting the water. After removal from the salt bath, the prints should then be trans- ferred to the fixing bath. This should not be made too strong. Fixing Bath. Sodium hyposulphite 3 ounces. Sodium sulphite li „ Water 20" „ The addition of sulphite is to preserve the purity of the tones. There are some amateurs, in contradistinction to those who will have the greatest simplicity, who prefer formulw of the greatest complication (take, for instance, some of the developing formulae published), and it is for these that 1 bring forward the following not too complicated method of toning, in two toning baths, the second being a toning and fixing combined. Jlarch 10, 189.S] THE BRITISH JOURNAL OF PHOTOGRAPHY. Ifil First tone very slightly indeed to a lifrht brown in the following the prints Imvins; bet>n previously washed, as usual) :— Potassium chloro-platinile •') grains, Sodium chloride 40 „ Citric acid 40 „ Water r'O ounces, and immediatelv transfer dirpct to thp combined toning and fixing bath as first mentioned in my papor until the desired tone is obtained. This produces tone^ of a rich, warm blaclf ; but, if purple tones are desired, tone first in the sulphocyanide. and then follow with the combined bath. Certainly the tones produced by it are very fine. Where prints are desired of a nice sepia, tone a little deeper in the platinum bath, and fix as usual in the ordinary way. Care must be tsken not to po beyond the brown stage. Prints produced in this platinum bath only are best finished off with a matt surface. As my paper is intended "to be devoted to toning only, I will leave the sub- ject of fijiishing, &e., to some other member to take up. ' ,1. B. B. Wellington. —*■ DEVELOPMENT OF EOLLABLE FILMS. Bkfobk the Putney Photographic Society on Monday, Febraary 20, Dr' W. J. Sheppard in the chair, Mr. J. B. B. Wellington, of the Eastman Company, gave a demonstration on Development of Eollable Fihns. In a short preface he gave a history of the improvements of these films, culminating in those manufactured by the Company at the present time. The chief advantages claimed were extreme lightness, portability, and the convenience of being able to carry 100 exposures, very great advantages when travelling. Having brought a roll of exposed films, Mr. Wellington showed how very plainly their new roll-holder marked the divisions between the exposures, thus getting rid ot a difficulty which had been experienced with the earlier patterns. Proceeding with the demonstra- tion, he first soaked the films in water, which certainly caused them to lie qnite flat during development. At least a dozen films were treated simultaneously, being placed face downwards, and care taken to keep them constantly moving by transferring those from the bottom to the top, in the same way as prints in a toning bath. This treatment is essential to ensure even development. The developer used was the pyro- soda recommended by the Company. Mr. Wellington stated that, in cases of under-exposure, better results would be obtained by long develop- ment than by increasing the quantity of soda. After development, the negatives wore rinsed and placed in an acid and alum clearing bath, washed thoroughly, and fixed. The final washing completed, the films were placed face downwards on an opal slab or glass plate, and squeegeed to get rid ot the superfluous moisture. They were then pinned down at the corners and allowed to dry spontaneously. The best way to store them was under pressure between the leaves of an album or book. During the discussion. Mr. Wellington stated that various marks which undoubtedly occurred in their films some time ago would not now appear, as great improvements had been introduced in their manufacture. ♦ THE STEREOSCOPE AND STEREOSCOPIC PHOTOGRAPHY.* No doubt some persons will at first find considerable difficulty in com- bining the two pictures when they have been mounted in this way, and this is because, as a rule, the eyes have a greater tendency to a near con- vergence than to a more distant one. When this is the case, the lenses of the stereoscope, if they are adjustable for separation, should be sepa- rated slightly until the pictures can be combined, and then slowly brought together again to the required positions. If the lenses are not movable, the best plan will be while looking through the stereoscope to push back the pictures as far from the lenses as the instrument will permit, and it will be found that while this is being done they will appear to approach one another. When they are apparently superimposed, pull them forward again slowly, and if the eyes are kept intently fixed upon them while this is being done, they may be drawn forward until the view is seen quite sharply without appearing to separate again. In many of the cheaper forms of stereoscope, instead of a pair of lenses, the two halves of a single lens are employed mounted so that their thin edges are together- Whole lenses are preferable, but they must be of equal focus. Sir David Brewster recommended the use of halves of a single lens, not only in the stereoscope, but also in the binocular camera, for taking the photographs, because of the difficulty of obtaining two lenses of equal focus. He con- tended that it was impossible to«obtain the necessary mathematical accuracy unless this was done ; but, whatever may have been the case then, there is no difficulty now in obtaining lenses that are sufficiently accurately paired for all practical purposes. * Concladed from page 138i The earlier stereoscopic photographs were taken, as yoa are no donbt aware, with a single camera and lens, the apparatus being moved a suit- able distance between the exposures ; and if it is not desired to photograph moving objects, this plan may still be adopted. It is not necessary to move the whole camera and stand. All that is required is that the tripod should have a rather larger top than usual to permit ot the camera being slid about three inches between the two exposures. Even this is not absolutely necessary. Mr. Traill Taylor has pointed out that it is suffi- cient if the camera be slightly rotated after the first exposure. I have tried this myself, and find a very slight rotation is all that is necessary ; but I would not recommend this method in preference to the nse of a divided camera and a pair of lenses. This is no doubt the apparatus that all those will use who, like myself, wish to obtain [their results with the greatest ease. Such a camera may be used either in the hand or upon the tripod, but in either case it must possess several good qualities in order to be satisfactory in use. IE it is for the tripod it should have a swing-back and rising front, and some means of adjusting the separation of the lenses. It should open out to focus when eight or nine inch lenses are required to be used, and close into three inches or less when a pair of wide angles are necessary. If it is to be used in the hand, many of these advantages may be sacrificed to lightness and portability ; but special attention should be directed to the shutter and the view finder. In both forms it is, above all, necessary that a good spirit level should be fitted, and careful attention paid to its use, for although in a single photograph we may easily trim the top and bottom to correspond with the horizon line, it will be found not nearly so simple a matter to counteract the effect ot carelessness in this respect in a pair ot stereoscopic pictures. Opinions are somewhat divided as to the size of plate that it is desirdble to use. Personally, I think that the advantage ot a plate larger than the standard size, 6J x 3^, will not often be found, but I must tell you that some gentlemen of very great experience recommend a larger. Mr Traill Taylor advises 8x5, which certainly permits a greater separation of the lenses when it is desired. Other sizes which may be used are 7^ X 4J, 6 J X 4f, and 6^ x 4;J. It is generally conceded that for all ordinary purposes of stereoscopic photography a pair of single lenses will answer equally as well as the more expensive doublets, even disregarding the somewhat theoretical advantage ot the former ot giving greater brilliancy because of the smaller loss of light by reflection. But, of course, where a large angle of view has to be included, a pair of short-focus doublets wiU be necessary, and there will be a slight gain in the use ot doublets where it is desired to obtain the maximum amount ot definition with a large aperture ot lens, as, for example, in photographing moving objects. It will be found that those pictures which have been taken with lenses ot about five-inch or six-inch focus, present in the stereoscope the most natural appearance, and tor this reason, that the eyes of the observer are then placed at about the same distance from the pictures as the lenses were from the plate when the view was taken, viz., about five or six inches, and the perspective therefore coincides with what we observe in nature. If shorter focus lenses are used, as they must be for many subjects, then the perspective is bound to appear somewhat exaggerated, and objects will appear smaller than they should do. It may be suggested that for the examination of these pictures lenses ot short focus should also be employed in the stereoscope, and I know of no reason why this should not be done. The amount ot separation that there should be between the lenses by which the photographs are taken has been the subject ot much discussion. Three to three and a quarter inches is the usual distance, but I am of the opinion myself that it should not so much exceed the distance between the centres of the eyes, usually about two and a halt inches ; and it will be found that it a very near object, eight or ten feet away, is photo- graphed with a greater separation than this, a strained and altogetlier unnatural appearance of relief will result when the pictures are seen in the stereoscope. Of course, if it is desired to represent distant objects with the relief due to those near at hand, it is necessary that the points ot view should be very widely separated ; but, if it is desired merely that the pictures when seen in the stereoscope shall present the same appear- ance as the view itself presented from the position at which the photo- graphs were taken, then the rule may be laid down that for an ordinary landscape with near foreground the distance of separation should not be more than three inches nor less than two and a half inches. As a stereoscopic camera makes its two pictures independently by separate lenses, it will be seen that each picture is inverted independently of the other. Therefore it is necessary, it the negatives are to be printed from by contact, either to divide and transpose them before printing or to divide and transpose the prints, unless each end ot the negative is printed from alternately. Which is the most convenient way will depend 152 THE RRITISH JOURNAL OF PflOTOGRA-PHy. [March 10, 1893 upon whether it is desired to make prints upon paper or transparencies upon glass. U paper prints are wanted, tlien it is generally recommended to print from the two negatives in the usual way on to one piece of paper, and when the toning, fixing, washing, or other processes have been gone through, and the prints are dry, to divide and transpose them, mounting the print which appears on the left-hand side, as they lay together on the table before you, on the right-hand side of the mount, and the right- hand print on the left-hand side of the mount. If it is glass transparencies that are required, then it will be found easiest to print alternately from each of the two negatives ; that is, to print from the left-hand negative on to the right-hand side of the trans- parency plate, and from the right-hand negative on to the left-hand side of the transparency plate. By means of a printing frame which is specially constructed for this purpose, and which may be procured from any dealer in photographic apparatus, and by using with it a set of cardboard guides, such as I have here, and which you may easily make for yourself, this may be done rapidly and easily. Care must be taken that each of the pictures is given an equal ex- posure, and I find, myself, that this may be done with sufficient accuracy by burning one inch of magnesium ribbon at a measured distance from each negative. Stereoscopic transparencies may be made in this way that will be good enough to satisfy the most particular ; but there is another way in which they may be produced that is, perhaps, superior in some respects, and is equally convenient when the work can be done by daylight. This is by copying the negatives with a divided camera, and a pair of short-focus lenses. This method obviates the necessity for trans- posing the pictures, for each negative is independently inverted by each lew, just as the picture itself was inverted when the view was taken. Another advantage of this method is, that one is able to arrange, with the most perfect accuracy, the desired distance of separation between similar points in the two pictures, which it is practically impossible to do exactly when they are printed by contact, owing to the fact that the glass of the negative and the glass of the transparency plate is seldom cut to the exact size. It is hardly necessary to mention that, when this way is adopted, the pictures may also be slightly enlarged or reduced in copying if it is desired. It is not necessary to have a special copying camera for this purpose. The camera and lenses with which the pictures were taken will answer almost equally well if it is attached to a board, at the end of which the negative is supported in a divided box. The arrangement which I use myself is, as you see, made on this principle. The effect of a stereoscopic picture is very much enhanced if, when it is seen through the stereoscope, it presents the appearance of being viewed through an opening. This may be produced in a transparency by having the openings in the mask at somewhat nearer centres than are the pictures themselves, and with paper prints by so trimming them that, when the.v are mounted, there is a little more of the view on the left hand side of the left-hand picture than there is on the left-hand side of the right-hand picture. The reason why doing this should cause the picture to appear as if it were viewed through an opening will be seen if it is remembered that we estimate the distance of an object by the amount of convergence of the optic axes necessary to see that object, which becomes greater when the object is near at hand than when it is remote. The openings in the mask, being at nearer centres than the pictures themselves, are seen with greater convergence, and consequently appear some distance in front of them. The same may be said of the edges of paper prints ; when they are at nearer centres than the pictures, the mount appears to be in front of them. The amount of separation determined upon between the centres of the pictures should, for the reasons I have before mentioned, always be mea- sured between two similar points in the distance, altogether disregarding the foreground; and here I am sorry to say that I find myself at variance with a gentleman who has by his persistent advocacy done a great deal in the last year or two towards bringing the stereoscope into favour again, Mr. Chadwick. In his Stereoscopic Manual, in which will be found much practical and useful information, he says : " It must be observed in these instructions that in all measurements it is the foreground which must be taken into account, and the distance will take care of itself." I claim that what should be done is the very reverse of this. All measure- ments should be taken between similar points in the distance, and the foreground will then take care of itself. The foreground must be right if the distance is correctly placed. The difference may be a small one, and it may be that when Mr. Chadwick's instructions are inteUigently followed the results will not be greatly different. There is, however, this to be said. If a view was taken in which was included a very near foreground indeed, it is quite conceivable that if Mr. Chadwick's instructions were followed we might find similar points in the distance so widely separated, that for the images of them to fall on corresponding points in each retina the optical axes would have to diverge if the pictures were examined in a stereoscope of the usual pattern. It should always be remembered that the stereoscope shows us its most remarkable effects when the photographs that are seen by its aid are placed at such a distance of separation that they are seen with the same convergence of the optic axes as the actual view itself was from the position of the camera in taking them, and when the lenses of the stereo- scope are of such a suitable focus that the pictures are seen sharply, clearly, and easily at a distance from the eyes equal to the focus of the lenses that produced them. When these conditions are complied with, and they will be complied with if the methods I have indicated are adopted in the production of the photographs, then it is impossible to imagine a more perfect realisation of the view represented than that which will be seen when the pictures are examined by the aid of a suitably adjusted stereoscope. J. A. Butleb. ♦- A CHAT ON LENSES. [Before tha Photographic Section of the Croydon Microscopical and Natural History Club.J On March 3 Mr.W. Low-Sarjeant delivered A Chat on Lenses. After a brief explanation of the elementary laws of optics, Mr. Sarjeant described the properties of the six varieties of lenses, and also of a seventh, called a " crossed " lens (a double convex lens, having its two curved surfaces of different radii). In photography, the use of a lens composed of a single element was attended with two great disadvantages, viz., chromatic aberration, or the non-coincidence of the visual with the chemical focus, shown by a want of definition in the photograph ; and spherical aberration, producing a similar result, owing to the rays of light passing through the margins of the lens intersecting at different points instead of at one and the same point. The first-named was corrected by the addition of another element with a different refractive index (crown and flint glass were the two elements commonly used), and the latter by the addition of a second lens, reversed, to correct the aberration of the first, as in a rectilinear combina- tion ; or it could be practically eliminated in the single or landscape lens, by using a diaphragm of relatively small size compared with the diameter of the lens. The purpose and uses of the stops were then explained. With a single lens, owing to the office performed by the stops, it was advisable to focus with the same stop it was proposed to use in exposing. The focal length of a lens was measured from its optical centre, the position of wliich, in the several forms of lenses, was shown by diagrams. To find the focal length of a lens— information often desired for various purposes— several methods of obtaining an approximately correct result were given. Focus a distant object in the camera, and the distance between the screen and the optical centre of the lens would be, roughly, the focal length ; or, focus some object, getting the image the same size! and the distance between the screen and the object would be about four times the focal length. The comparative advantages of the use of long and short-focus lenses were then discussed. A long-focus lens was most suited for ordinary outdoor work, as the natural proportions between near and distant objects was better preserved in the photographs taken with it. The " chat " was illustrated by a largs number of diagrams, and was listened to with much attention by the members. The questions which were afterwards discussed showed that they had been enlightened on many hazy points, and would, consequently, be enabled in the future to use their lenses to better advantage. PEACTICAIi EEMAEKS ON LANTERN-SLIDE-MAKING. [Dnndee and East of Scotland Photographic Association. At the fag end of a meeting last session, Mr. Baird passed through the lantern for me a number of my slides, interesting chiefly because made by some of the less-used processes ; and, as I have been repeatedly asked by members of the Society to show them again, I have extended tlie idea somewhat, and pose to-night rather as an experimentaUst than a practical slide-maker. When I take up a process, I generally keep at it until I have made what appears to me the most of it ; in any case, I never stop short of being able to produce presentable results by it. In many instances I have gone on until such time only as I had mastered the process and produced one or two slides by it. It frequently happens that a process may be capable of giving very fine results at times, and yet not such a process as one would care to work constantly. In such oases, it is excellent practice to make a small study of the subject, and after attaining success to " leave it for fresh fields and pastures new." You will please understand, therefore, that the slides which are to be shown 3-ou are not shown as models of what slides ought to be, but merely as fair specimens of the various processes they are to illustrate. Almost every process requires (if one is to make the most of it) a March 10, 1893] THE BRITISH JOUIINAL OF PHOTOGRAPHY. 1C3 apeoial quality of negative. It follows from this that I have had to pick out from my iieKatives one suitable for the proceaa in hand rather than one artistically good. Let no one, therefore, go away, saying there is nothing special in this slide or that slide ; the production of a pretty picture was not always the aim of the experiment. While, therefore, safeguarding myself against the imputation of putting these slides forward as being something specially fine, I, nevertheless, claim that they represent fair average work of the various processes touched upon, and suoh as auy one designing to work any of these pro- cesses may attain to, with the moe floated ; and (4), generally, to arrange a working scheme to be sub- mitted to a future public meeting. The Executive Committee have already met to carry out the terms of the instructions given at the above meetir.g, and in the course of a week or two another public meeting will be called for the purpose of consider- ing the decisions at which the Committee wiP. have arrived. Numerous promises of membership were received in the room, making a total, with others sent by letter, of about eighty — a remarkably good number for one evening. The following comprise the Executive Committee :— Messrs. Birt Acres, Eobert Beckett, R. P. Drage, A. C. Edwards, T. Fall, T. E. Freshwater, F.R.M.S., John A. Hodges, J. Howson, William Fenton-Jones, Charles H. Oakden, E. J. Wall, H. Snowden Ward. Th« Hon. Secretary {pro tern.) is Mr. Thomas Bedding, 2, York-street, Covent Garden, W.O. RECENT PATENTS. APPLICATIONS FOR PATENTS. No. 3699.— "Improveinent.'i in Stand for Photographic Cameras." H. W, Taint.— /Mterf Fehnutrt/ '20, 1893. No. 3791. — " Iraprovements in Gratings or Screens for Photo-mechanical Printing." Complete specification. M. Lkvy.— Dated Fehnuiry 2\, 1893. No. 3804. — " Improvements in Klectro-photogriphy." J. Waring. — Doled February 21, 1893. No. 3847. — " Improvements in the Production of Lantern Slides and other Transparent Photographic Irnajies, in which are also contaitied an Improved .Means of Transferring Pliotographic Rjproiluctions to Porcelain, .Metal, and otlier surfaces." U. Mitchell.— Orttoi February 'il, 1893. No. 3919. — "An Improved Pneumatic Shutter for Photographic Purposes." A. Philbukn.— flatoi February 22, 1893. No. 3964.— "Improvements in or relating to Photo-mechanical Printing." W. R. Andhi^;, W. R. a. Sleioh, and A. B. A. ^LKian.— Dated February 2:3, 1893. V < No. 3989. — "Irvine's Improved Twin Lsns Hand Camera." J. Irvine. — Dated Feh-uary 23, 1893. No. 4030. — " (n\iirovemonts in Shutters for Photographic Lsnses." F. fiHRW.— Dated February 23, 1893. No. 4057. — "An Improved Photogiaphic Camera for Portraiture and for Studio Work." J. V. Robinson.— Oa^&i February 24, 1893. No. 4065. — " Improvements in the Construction of Hand Cameras and Dark Slide-s therefor." W. Middi.emiss. — Dated February 24, 1893. No. 4141. — "An Improved Photographic Printing Ajiparatus and Process." II. S. Rush, H. L. Jenkins, and W. G. G03SLiN.~-/Jaterf February 24, 1893. No. 4167. — "Improvements in and connected with Extension Linkages for Photographic Cameras and other Collapsible Apparatus." G. Wishabt. — Dated February 25, 1893. No. 4183. — "Improvements in Photographic Cameras." T. Miller. — lMte.d February 25, 1893. No. 4188. — " Improvements in Electric Retouching of Photospaphs, and in Apparatus therefore." R. Kennedy. — Dated February 25, 1893. No. 4214. — " New or Improved Apparatus for the Manufacture of Films, more especially intended for the Manufacture of Films for Photographic Purposes." W. H. Walker.— />rti;crf February 25, 1893. SPECIFICATION PUBLISHED. 1892. No. 19,581. — " Photographic Shutters. " Clarke. PATENTS COMPLETED. IMI-BOVE.MENT.S IN MeaN^ KOH RAISING AND LOWERING AND SF.CUBING IN Position STuhjo Ca.mera Stands and Other Objects. No. 5672. Walter James Boughton, King-street, Tlietford, Norfolk. January 28, 1893. My invention, a studio camera stand for jihotographers or others, or any article required to be raised up and down, to be kept in position wherever wanted witiiout the aid of set screws. My invention consists of two ujiright standards grooved for cords, with cross feet, connected by two cross bars ; in between the bars is a spindle, with cords coimected, to raise and lower the platform between the two standards, a wheel on spindle to raise and lower • with wedge arrangement. Impbovkd Portable Phcitugbaphing Apparatus. No. 6631. JULBS Carpentier, 20, Rue Delambre, Paris, France. January 28, 1893. This invention has reference to a small portable apparatus for taking photo- graphs, which has the general configuration of a binocular opera-glass, tne one barrel of which serves as the photographing camera, while the other serves for sighting, the glas.ses .at the small ends of the barrels being the object lenses. The two barrels are connected at their small ends by a cross frame, in which is a sliding shutter, by means of which the object lens of the camera can be momentarily uncovered for taking the photograph. This shutter lias for this purpose an opening, which, when in its inward position, is situated on the inner side of the object glass, while, when in its outward position, it is on the outer side thereof. The shutter is acted upon by springs tending to draw it into its inner position, and when drawn out into its outer position it is held by a trigger catch, on releasing which with the finger it is drawn rapidly by the spring into the inner position, thereby momentarily exposing the sensitised plate in the camera. In order to prevent such momentary exposure from also taking place when drawing the shutter outwards, there is provided a small slide on the shutter, which covers the opening thereof while the shutter is being drawn outward until the opening has passed beyond the object lens, when a stud ou the shutter comes in contact with the end of a slot in the frame, and it is thus held while the outward motion of the shutter is completed, whereby the opeuuig becomes uncovered by the slide, which, on the inward motion ,of the shutter, moves back with it, leaving the opening uncovered. The two barrels of the appiiratus are fixed on to a rectangular bo.x, in which is a sliding drawer, to which is attached a stem, projecting to the outside, where it has a button, by means of which the drawer can he drawn from that sid* of the box which is opposite the camera barrel to the other side. i 156 THE BRITISH JOURNAL OF PHOTOGRA.PHY. [March 10, 1893 The end of the drawer opposite that to which the rod is attached is not closed, but from the opposite sides two small claws near the top project into the open end. The bottom of the drawer is also open, and two slightly curved blade springs extend from the closed end of the drawer along the open bottom. In this dr.awer are stored a number of sensitised plates, each of which is contained in a tliin sheet metal frame, which frames separate the plates from each other. Each of these frames carries a number marked on a recessed part thereof, and the number of the bottom frame in the draw will be visible through a red eyeglass fixed in the bottom of the box opposite the sighting object glass, when the drawer has been drawn to that side. The frame carries a light spring which presses the sensitised plate against the rim of the frame, and thus holds it securely in position. For introducing the frames with their sensitised plates into the drawer, the bottom part of the end of the box on the camera side is made as a door, and, on opening this, the frames are then slid in, one on top of the other, over the before-mentioned curved springs at the bottom, which, when the box is full, press the uppermost frame and its plate slightly into the larger open end of the barrel which constitutes the camera, stops being provided for preventing the entrance of theframe to an extent exceeding its thickness. The door of the box being closed, the apparatus is ready for taking a photographic impression on the said plate, after which the drawer is drawn outward by its rod, whereupon the u])i>ermost frame with its plate, being held by the stops as described, will remain in position while the others .slide from under it with the drawer, and when this is entirely withdrawn the said frame, losing its support, will fall to the bottom of the box. On now pushing the drawer back again, the said frame will pass in between the curved springs and the undermost frame of the pile in the drawer, and will thus be- come the bottom plate, while the second uppermost one will at the same time be pressed into the camera as above described, in order to be exposed at the next operation. In this way, by moving the drawer backwards and forwards after each exposure, each plate is in its turn brought automatically into the camera, while the preceding one is brought automatically to the bottom of thebox. . The sighting barrel of the apparatus is, by preference, constructed with a concave object glass, and with the before-mentioned serai-convex red eyeglass in the bottom of the box for observing the object to be photographed. It may, however, have a photographic lens and a transparent screen, like an ordinary camera. The negatives taken in the above-described instrument are, of course, on a miniature scale ; in order to obtain therefrom positives on an enlarged scale, I provide an apparatus of the following construction : — A rectangular box has at bottom a frame in which is a movable plate, and whicii can open away from the box on hinges, like a door, being held close by a spring catch. The sensitised paper is placed upon the movable plate, and is held in position by being pressed by tlie plate against projecting ledges on the box by tlie closing of the door. On the upper side of the box is tixed a metal tubular extension, the upper end of which is adapted to receive the small negative taken in the first-described apparatus. At a suitable distance from the negative the tubular extension carries a partition, in the centre of which is an object lens, by means of which an enlargement of the picture of the negative is thrown on to the sensitised jiaper at bottom. The top of the tubular extension is closed by a cap, which is removed for the length of time required for the exi)Osure, and is then replaced while the apparatus is being taken to the dark room, where the .sensitised pajier is removed ami treated in the usual manner. For making this apparatus more (iompact for carrying, the tubular extension is made removable from the box, and is fixeil in position by a bayonet joint or other fastening. Improvements in ok relating to the Reoui^vtion op PHOiooBArHic Shutters. No. 19,581. Joseph Thachkr Clakke. Boston, Massachusetts, United States. —Februm-y 4, 1893. My invention relates to photographic shutters of that class in which the dura- tion of the exjiosure is governed by a pneumatic piston .and cylinder, acting as a brake of variable effect. Hitherto the differentiation in the action of snch pneumatic brakes has been attained in two ways, either by varying, by means of a tap or of a movable cap valve, the orifice through which the comjiressed air is per- mitted to escape from the cylinder, or by so shifting the position of the piston arm in relation to the working parts of the shutter that the leverage exercised by the shutter spring upon the piston is changed, and the length of the piston travel is thereby altered. My invention has for its purpose to provide an improved pneumatic shutter in which the requisite difi'erenliatiou of the brake is effected in a third and novel manner. While dispensing with the valve for regulating the outflow of air from the cylinder, and while leaving the leverage between the shutter spring and the piston unchanged, and the length of play of the piston un- altered, I obtain the variable speeds of my pueumatic brake by sliding the air-compressing chamber or cylinder to and fro along the axis of the piston rod in such wise that the piston is caused to plunge to a greater or less depth into the cvlinder, the retarding efiect of which is thus restricted to a longer or shorter part of the travel of the piston. In this movement of the air-compressing chamber, relative to a piston of fixed travel, lies the gist of my invention. The movable air-compressing chamber, or sliding cylinder, being provided with no variable outlet, is preferably made to fit the piston somewhat loosely, so that the air com])ref sed tlierein by the movement of the piston may gradually escape between its inner wiUls and the .sides of the piston. In the event of the leakage thus provided between the piston and tbe cylinder being found insufficient, a further o\itlet may be provided by piercing one or mere small apertures in the walls of the cylinder. These apertures may be so arranged as to gradually cut off the outflow, and consequently to increase the resistance of the air remaining in the cylinder, as the piston passes them on its travel. The air-compressing chamber may be constructed as a plain cylinder closed at its base, like a stopped organ pipe, so arranged as to slide along the line of play of the piston, permitting this to move, at the one extreme, both forwards and backwards without entering it, and thus without compressing the air within it, or, .at the other extreme, to traverse its entire course within the closed cylinder, under pneumatic restraint. Or, while arranged to slide in the manner indicated, tlie air-conipresbing cliamber may be made with a slightly conical bore, so as to gradually alter the amount of air leakage between its walls and the sides of the piston as this latter is caused to jienetrate more or less deeply within it. Such a slightly conical bore will reuder the pneumatic retardation more or less appreciable, according as the piston travels along a more or less constricted portion of the bore. In either case it is preferred (although the principle of the invention is in ao wise dependent hereupon) to make the air-compressing chamlier greater in length tlum the travel of the piston, cutting out longitudinal slots or otherwise perforating all that portion of the tube through which the piston travels when the cylinder is so withdrawn as to exercise the least ]iossible restraining effect. Through these slots or perforations the air, displaced by the movement of the piston, finds free escape, and hence exercises no retarding influence. The rails formed by the strips remaining between tlie slots may serve as guides for the piston during that portion of its travel in which it does not enter the un] perforated portion of the air-compressing chamber. The piston may be connected with, and receive its motion from, any portion of the shutter worked by the shutter spring. Thus, if the shutter plate be of that type which performs an entire revolution for each exposure, the piston may work \ipon a cam or eccentric, the position of which in relation to the centre of revolution will ileternune the play, forwards and backwards, of the piston. If, on the other hand, the shutter be of a type moving to and fro across the lens aperture, the piston may be advantageously made to work in a slot in the shutter plate, or be connected therewith in any other convenient manner. The piston can, if preferred, be directly connected with the ojierat- ing spring of the shutter jilate, as is well understood. In shutters of the type last mentioned the piston will be moved bacltwards, i.e., away from the air-compressing chamber, by the act of winding the shutter spring, and will differentiate the length of the photographic exposure only during its forward travel. The adjustment of the air-compressing chamber, for the purpose of setting the speed of the shutter, may be performed in any convenient manner, either by direct action of the fingers upon the cylinder itself, or, as in the case of hand cameras with closed fronts, hy means of an intervening lever or other shifting device. A scale, indicating the speed to which the shutter is set, may be engraved, or otherwise marked, either in connexion with the cylinder or with the moving lever. It is obvious that the principle of my invention may be retained, although the relative ]iositious of cylinder and piston be so reversed thivt the former is connected with some moving portion of the shutter and the latter adjusted by sliding along the line of travel. One of the notable advantages of my improved pneumatic shutter is that, even in protracted exposures, the lens aperture is opened (and in the case of shutters of the before-mentioned circular type is likewise closed) with the maximum rapidity of the shutter. This is due to the fact tliat the yiiston is permitted to conmicuoe (and in shutters of the circular type likewise to ter- minate) its movement without restraint from the pneumatic brake, the retarding effect of which is not brought iiito action until after the shutter has lieen passed aside from the lens aperture by the unrestrained force of the shutter spring. The character of the photographic exposure is hereby greatly improved. — » MEETINGS OF SOCIETIES FOR NEXT WEEK. Date of Meeting. March 13 13 13 .... 13 13 IS 13 13 U U 1* U H U 14 U ... . M 15 15 15 15 15 15 15 16 16 16 16 .. .. 16 16 .. 16 .. 16 17 17 17 17 17 18 Name of Society. Place of Meeting, Camera Clnb Darlington Dundee Amateur Lantern Society Norfolk and Norwich North Middlesex Ptitney Iliehmond Birmingham Photo. Society Derby Great Britain Hackney Manchester Amateur Newcastle-on-Tyne&N.Countiee Paisley Rochester Stockton Brechin Bnry Leytonstone Manchester Camera Cinb — Photographic Club Sonthport Southsea.. ; Birmingham Photo. Society Camera Club Glossop Dale - t:re3uock « Hull London and Provincial Oldham Oxford Photo. Society Cardiff CroTdou Microscopical Holborn LeaminetoD Maidstone Hnll Charing Cross-road. W.C. Trevelyau Hotel, Darlington. Asso. Stndio, Nethergate, Dundee* 20, Hsnover-sqnare. Bell Hotel, Sora-ich. Jubilee House, Hornsey-road, N. Boys' (Tymii:isinin,Charlwood-roacI, Greyhound Hotel. Clnl> Koom, Colonnade HoteL Smith's Restiiuraut, Victoria-fit. 50, Groat Russeil-st. Bloomsbnry. 206, Mare-street. Ruckney. Lecture Hall, Athonaenm! Central Exchaiiire .^rt Gallery. 9, Gauze-street, Paisley. Mathematical School, Rochester. Mason's Court, Hiirh-street. 14, St. Mnry street. Brechin. Clult Rooms, \S, At.^ar-street, Bury, The Assemljly Rooms, High-road. Victoria Hotel, Manchester. Anderton's Hotel. Fleet-street.K-C. The Stndio, 15, Cambridge-arcade. 3, King's-road, Southsea Clnb Room, Colonu-ade Hotel. Charing Cross-road, W.C. Museum, Kelly -street, Greenock. 71, Prospeet-stroet, Hull. Champion Hotel, 15, Aldersgate-st. The Lyceum, Union-st., Oldham. Society's Rooms, 136, High-street. Public Hall, George-street, Croydon Trinity Church Room, Morton-st. "The Palace,'* Maidstone. 71, Prospect-street, Hull. March 10, 1693] TUB BRITISH JOURNAL OF PIIOTOGRAI'IIY. LONDON AND PKOVINCIAL PHOTOGRAPHIC ASSOCIATION. March 2,— Mr. W. H. Hnrrison in tlu' clmir. Mr. Bilgar C'lilton, being unwell, was iinuhle to deliver his pronjised lectnre on Camtras, Tripoils, ami hark .Slitlea, and it wa» postponed accordingly. TllK QuKSTioN Box. 1. "Arc I'l'rro-pnuisiate prints pernuuieDt y if not, can their permanency be increased in any way .'" The Chaiuman saiil lilui' prints were very mnoli affected by alkalies. Mr. G. W. Atkins luid some by him wliich were made ten years ago; they hail been vamislied, and were as good as ever. 2. "A dry plate, developed, tixeil, and washed in the usual way, vat dried off with spirit ; when dry, large patches of a whitish deposit were noticed on the film next to the glass. Is this detrimental to permanency of negative, anil what is tlu' cause ' This has only been found when working with the new spirit, and does not appear to affect the printing of the negative." Mr. W. K. Dkhexham thought that insuflicient washing was the cause. Mr. G. T. Harris had been troubled in the same way, but found, however, that the deposit disappeared in varnishing. . 3. " What would be tlie best printing paper fo send to the (Jold Const, as platinotyjie, silver, and bromide paper are spoilt by damp in less than a week?" Mr. T. R FRB8BWATBR said he had seen prints which had been done on silver paper set out ready sensitised to India, ami which seemed to stand well. Mr. Debeniiam would suggest the use of coUodio-chloride paper. Mr. J. S. TiAPE said that if the silver prints were coated with a weak solu- tion of gelatine on both sides, left to dry, then again coated on both sides with a spirit varnish, he thought they would be as permanent iis could be desired, even in a climate like that of the Gold Coast. Messrs. P. Everitt and F. W. Pask were again appointed delegates to represent the Association on the Athliation Committee. The Hon. Skohhtahy announced that on March 18 a large collection of lantern slides (including some astronomical), illustrative of South Africa, would be shown. 167 Noitb Middlesex Photographic Society.— March 1, First of a series of Elementary Technical Classes, Mr. J. MilNTOsH taking charge. — He explained the different sorts of lenses, their uses, and how to test them ; the stops, their uses, and their relation one to another as reg.ard3 exposure, the camera, swing- back, rising front, showing and explaining various tests ; he also touched upon plates, and made a point of the advantages gained by backing the same. These classes are given expressly to help beginners, free of charge ; any gentle- man wishing to attend should make application to the Hon. Secretary, Mr. G. Gosling, 13, Lansanne-road, Hornsey. An outing has been arranged to Hampstead for Saturday, March 11, which will be attended by several members of the Society to give jiractical instruction in the use of the camera in the field, and will be follow«l on Wednesday, March 15, by an evening for developing the plates exposed. Harringay PbotograpUc Society.— March 2, Mr. Towers occupied the chair.— Mr. Mori-.an, rejircsenting Messrs. Fuerst Brothers, gave a demonstra- tion with amidol. In introducing this comparatively new developer, Mr. Morgan said its advantages were extreme energy, its very small bulk, and it does not reiiuire an acid clearing bath for bromides. The demonstrator success- fnlly developed a half-plate (Edwards' isochromatic plate), and Thomas's lantern plate, and some bromide paper. Mr. Denxktt said he liked the brown tones as produced by pyro for the ordinary negatives, and Mr. Towers said, tliough the lantern slides and bromides were perfect, he should prefer pyro for ordinary negatives. Some excellent enlargements, done by Mr. A. R. Dresser, and developed with amidol, were shown. Mr. Morgan strongly recommended the concentrated stock solution, and he also said there was quite as much control with amidol as any other developer. Haclmey PliotograpMc Society.— February 27, Mr. F. Houghton in the chair.— Mr. Hudson handed up a liome-made shutter. The working was, how- ever, too too stiff in its action. Mr. A. Barker presented slides to the Society for lending out. Mr. Grant showed .>iorae printout opals. A discussion ensued on the desirability of the Society being represented at the forthcoming Crystal mace Exhibition. The matter wa" referred to the Council to be thrashed out. Mr. ViNi.vo asked : " What is a simple way of obliterating portions of a nega- •ive .so as to omit some in printing and without leaving a hard line !" Mr. riiAXT said that Mr. H. P. Robinson described the method in his book. Mr. AVENs a-sked : What had the Society done about tlie proposed new lantern lenses ? Through the kindness of one or two members it was decided to pur- chase two, made by Messrs Swift. A series of prize slides were then shown, after which slides by Messrs. A. Barker, S. J. Beckett, Dean, Grant, Hull, Moore, Harvey, Roofe, Tavener, and G. W. Wilson, of Aberdeen, were shown. Croydon Camera Club.— February 27.— It was announced that the Judges appointed tor the forthcoming Exhibition were Colonel J. Gale and Mr. T. J. Bnght. Halifax Camera Club —February 28.— Mr, J. E. Jones introduced the sub- ject of Laiid.icajie or Tourist I'hotoijraphy. Mr, JoNJS described at some length the apparatus best adapted for the touri.st. He did not believe in the long-focus camera when on tour ; the double extension was never re«6'«Knto weighed heavily at the end of a dav's journey. A small lamp, with non-actinic medium, was very useful for chang- ing plates, with the window covered up with the focussing cloth. He had round the tiest way to store plates or films after exposure was to place a thin Meet of non-actinic paper, cut to size of plate, between every two plates, films to the paper. Films have an immense atlvantage over plates on account of weight A very slow jilate had certain advantages in landscape work, but for all-round work a moderately quick one was more desirable. He always carried • ')Ottle of Kay's Coaguline, which he found very useful in cases of accident, such as the breaking of the focussing screen, 4c. He had uwd various kinds of Icn.ses, including the single landscape, but he found nothing like Roee' rapid symnietricnl, which he mvariably used at al»ut/-'22. He considered the legs of the tripod and the foc-iiMing cloth great nuisances, and, as a partial remedy for the latter, exhibited Houston's focussing doth holder. His plan wa« always to use a normal developer, and, if a i)ictnre did not come out without all sorts of dodging, he did not think the plate worth further trouble^ He ba , in 1856. Two phctographs of Market-xtreet, tVeiUngooroujh, in 1856, four p wto- graphs of Princess Kaiulani of Hawaiian Islands. WouLD-BE Member.— See " Lantern Notes and News," last week. Spring.— Return the films to the makers ; they will, doubtless, give yoa freth ones for them without demur. F. ]{. E. (Weymouth). — The Pampheugos lamp is made by Mr. W. C. Hughes, Brewster House, Kingsland, N. J. W. C. — Mr. Denison is not a professional photo-eugraver, and does not work for the trade as you have been erroneously informed. Hector Maclean, Marcus P. FuoHS, J. R. Singer. C. Ray Woods, Pbb- plexed, and others. — Received ; thanks. In our next. Ink Stains.— Try the effect of a dilute solution of either citric or hydrochloric acid for removing the ink stains from the photographs. Experiment says : " Can any reader give the formula for white ink for writing. on glass so tliat it will not only write, but etch the surf ice V Sole Rights.— If you have copyright in the picture, then by registration you can proceed for damages if another person makes copies thereol. Rupert Hollett. — It is the object-glass of the telescope that must be used;. and, of course, tlie camera must be erected at the eyepiece end. Ajax. — The iodo-albumen process is described in the Journal for June 17 of last year. So far a-i we luiow, it is not now worked commercially. " Lantern Rkcordite."— You were misinformed; the '■ Lantern Record " will appear during the summer months. See editorial announccmeut else- where. "H. Lewis" ("Brooklyn, U.S.A.").— You are too deliciously simple if you imagine that we cannot penetrate such a poor disguise. Try again. C. Porter. — You would be rendering yourself liable to prosecution by making and exhibiting lantern slides of the engravings named without permission. Talc. — Mica is being introduced by Mr. Rudowsky as a support for negatives and positives, and therefore would answer lor lantern pictures. It is, how- ever, very expensive yet. Puzzled Photographer. — However much their admirers may like fuzzy photographs on paper, we ,do not think they are likely yet to iuiroduce lantern slides from the negatives to a general audience. R. O. S. — If the mounts were gu iranteed by the vendor, or his agent, to have no- injurious effect on the photographs, and you can prove that they have had, you have a good cause of an action at law for damage to your reputation. W. J. Clutterbuck.— Solutions of ferrous oxalate and mercuric chloride may be ordered of any dealer. For use, employ the latter at the strength yoa receive it, and dilute the former with three times its volume of water. If you desire to make the solutions yourself, the quantities are given in the Almanac. B. W. C. — 1. An attachment for keeping the tripod perfectly steady has been patented by Messrs. George Mason and A. L. Henderson. Send us a descrii)- tion of yours, and we will say if it is patentable. 2. -^pply to Mr. H. N. King, 4, Avenue-road-villas, Goldhawk-road, W. Stone & Wilkinson asks : " What is the best reagent to use to precipitate the silver in the washing of P.O. P. ? Have tried H.C.I, and Na CI without effect." — If the substances used do not throw down the silver, tlioiigh we should have thought they would, use sulphide of potassiufa— liver of sulphur. J. Waite.— The picture.s are very good, but they would have been mfinitely better if they had been printed by the platinotype process. Winter effects are never well represented by being printed on albumen paper and toned to a warm brown tint. The cold tones of platinum are best suited for winter pictures. F. Bhain.— If you have proper retouching medium and pencils, and have read all that has appeared in the Journal during the last few ye-ars, and yet do not get on, we should advise you to have a few lessons from a practical re- toucher. We cannot, of course, without seeing examples of tne failures^ indicate the causes of them. J, Lane.— We cannot tell what your slides are like as regards quality, fh)m such a vague — or, indeed, any— description. Join a pliotographio society that has lantern nights, and exhibit your slides among those of the other members. Volumes of criticism would be worthless as compared with that way of finding out whether the sUdes are good or bod. 160 THE BRITISH JOURNAL OF PHOTOGRAPHY. [March 10, 1893 W. A. T.— 1. Tlie formula given in the Almanac is the best luiblished. 2. Many jirofessioiial photographers sensitise tlieir own jiaper because they consider they get better results than buying it ready sensitised. It is also, to them, more ecouoniical. 3. Yes, if "the wooden vessels are coated with paraffin or other impervious material that has no injurious effect on the silver solution. P. Casey.— Your local chemist and druggist is in error. Sulphate of soda is . not what you want, and it is not the same thing as sulphite of soda. It is the latter you must have. Better obtain it from a dealer in photographic material. Ifvou succeed in obtaining it from a village druggist it is very doubtful if it will be of good quality, and unless it is it is useless for photo- graphic purposes. A. HoBTiiN.— 1. Expose the cleaned surface of a glass plate to the fumes of fluoric acid, which are generated from fluor spar and sulphuric acid in the bottom of a lead or guttapercha dish. 2. There is no rule for placing the stop in your lens. 3. The rays from opposite sides cross the axis after transmission through the first lens of the combination. Axial rays meet only at the focal plane. ■C. Slade. — In photographing an interior, if the camera is placed directly facing the mirror at the end of the room, so that it is reflected in it, the apparatus will necessarily show in the photograph ; but, by a little judgment, the camera may no doubt be so placed that its image is not reflected on to the lens. An alteration of a few inches in its position will often be sufficient to get over the difficulty. Omicrox. — The stains are caused by the prints being stored so long in a moist condition. Stains precisely the same as these can be produced at will by keeping prints in a pile closely pressed together for two or three weeks according to the temperature. The more perfect the wa.shing the quicker are the stains likely to appear, particularly if the conditions favour mildew. In future, we suggest the prints be dried prior to delivery, A. Y. E.^The design for the studio is so good, that we can suggest no real improvement imtou it. With regard to the other question, we can offer no opinion, as the law, as regards building is not the same in different districts. As the erection will be a conspicuous one, we should advise you to consult, with the plans, the surveyor to your local authority before commencing to build. By doing so you may save yourself a lot of trouble and delay. A. S. Bone. — An ordinary typographic press, such as the " Albion press " you possess, will answer quite well for collotype printing. Indeed, this is the form of press that is extensively used by collotype workers in this country. Power machines are necessarily expensive. They vary from about two hundred and fifty pounds to double that sum, according to size and maker. The power required to drive them is not great. A gas engine of one horse power would be equal to working a couple of moderate size. Lionel Hartswn asks: "How can I obtain particulars of a kind of photo- graph introduced many years ago ? It was a crystal cube, with portrait inside, and I believe it was called the 'Casket Portrait,' and done only by the inventor at a studio at Charing Cross. If it was patented, what year about was it ?" — The Casket portrait was the invention of Mr. H. Swan, and was patented by him in 1862. The number of the patent is 3249 for that year. The specification, giving full particulars, costs eightpence. "Edmund Stirling (Philadelphia) writes : " I was greatly interested in the letter of Mr. Haes in your issue of February 10, in which reference is made to flexible steel tubing and its uses in connexion with the lantern. I would be under renewed obligations to you if you could advise me where I could get samples and specific information as to such tubing. Do you know whether it can lie had in this country?" — In reply. Particulars of the tubing are given in the "Lantern Record (Supplement) " for March 3. T. Mathh writes : " 1. I have a set of moist water colours, which have become too dry to work easily. Will it do to mix them with honey or glycerine ? I might say that I use them for colouring bromide prints. 2. How to make them transp.arent for lantern slides 1 3. Where can I get lantern slides on hire?" — 1. It would scarcely be worth the trouble to attempt to remix the colours. Possibly, if they were kept for a few weeks in a very plied with the low-quality oxygen, tliis inferiority was less than had been anticipated from the disparity in the quality of the two samples employed. The increased consumption which you mention was most marked. 1 may, perha])s, emphasise the point by stating that, in a test made between two samples of oxygen of 92 '4 % and 67 '0 7o quality respec- tively, the consumption of the low-quality oxygen was just 50% more than that of the high-quality gas, and the illuminating power was even then con- siderably less, and this was especially marked in the delineation of shadows thrown on the illuminated disc. I consider the difference in qualities of oxygen is more appreciable in the actual consumption of the gases than in their illu- minating effect on the lime ; but, apart altogether from the question of con- sumption, I consider a gas of only 60 7<, purity would spoil any lantern show. I am conscious of not having explained myself sufficiently on this point, ami shall be much obliged if you will kindly put the matter right in your next issue." Round West London with C^•CLE and Camera. — Before the West London Photographic Society, on February 28, Messrs. Stein and Varden read their joint paper on Round West London with Cycle and Camera. After detailing how a few members of the Society had banded themselves together into a cycling division, the authors dwelt on'the advantages of combining cycling witli photography. The cyclist did not feel the weight of his camera, for it was carried on his machine. The paper was profusely illustrated by the lantern, the slides being from photographs by the joint authors, commencing with a short series of pictures illustrative of the evolution of the modern cycle. Thi- authors described verj- happily a circular cycle trip that could be easily managed in one day, starting from Chiswick and taking their audience, in imagination, through Acton (or Oaktown), Ealing, Hanwell, Perivale, Green- ford, Northolt, HaiTow, Pinner, Eastcot, Northwood, Ruislip, Hilliugdon, Uxbridge, Cowley, West Drayton, Longford, Harlington, Hayes, Heston, Osterley, Isleworth, Brentford, Boston Road, Strand-on-the-Green, ami back to Chiswick by way of the Mall, Hammersmith, and Stamford Brook Green. The journey thus indicated was described in detail, with much intei'estiiiir information about the places visited, both as regards their past history and present appearance, and, in the interests of those members who require a plen- tiful supply of landmarks to guide them, the authors mentioned by name the many wayside inns they encountered on their journey. The run described in- cluded but a part of the Western District of London, and there were other routes of equal interest, embracing such places as Esher, Weybridge, Ripley, Virginia Water, Windsor, Kingsbury, Roe Green, Preston Green, Stanmore, and Whitchurch. OONTBNTS. Faoi notice-tub "LANTERN RECORD".. 11.-. HOW business may be revived.... 146 PHOTO ■ LITHOGRAPHY FOR AMA- TEURS HO STUDIO-BUILDING. By G. W.VTMOUSH WEBSTER, F.G.S US A NEGLECTED DEVELOPER. By W. li. liOLTON U9 ON THE TOSINO OF SOLIO PAPER. By .1. n. n. WELLINGTON ISO DEVELOPMENT OF llOLLADLE FILMS 151 THE STEREOSCOPE AND STEREO- SCOPIC PHOTOGRAPHY. By J. A. UUTLER 151 A CHAT ON LENSES „ 162 P MEETINGS OF SOCIETIES 15" FORTHCO.MING EXUIEITI0N3 16' CORRESPONDENCE 16- ANSWERS TO C0BBESP0NDENI8 U-" THE BRITISH JOURNAL OF PHOTOGRAPHY. No. 171 :.. Vol. XL.— MARCH 17, 189.3. MIXED DEVELOPERS. It occasionally happens that a batch of plates is met with which, without being actually bad, requires some special kind of development to secure a satisfactory image. This is far less freciuently the case at the present day, since the manufacture of commercial plates has been brought to a degree of uni- formity, than was the case a few years back, for it is the practice in most of the large establishments to test each make of emulsion before spreading any considerable quantity, and any such doubtful lots are either rigorously rejected, or, if the quality be such as to admit, mixed with other lots of opposite character. We came across such a sample of plates a few days back, a small lot which hail been made for experimental purposes, and which, according to a memorandum on the package, had lieen found wanting in density, though otherwise good. This seemed a favourable opportunity for testing the capabilities of mme of the newer forms of developers which had not been available at the period the plates were made, an opportunity of which we at once availed ourselves. The ])articular liatch of plates wa.s some seven years old, a fact which in itself would be considered amply sufficient to throw doubt ufK)n the quality of the films ; but we may remark fn pngmnt, that, given a good plate to start with, that is to say, a plate that has been properly treated in manufacture, more especially in the removal of all soluble matter from the emul- sion, age alone does not neeessarilj- produce any deterioration. We say " «'/? dlone" because it is obvious that, if the condi- tions of storage have been such that other complications are introduced, any sort of change may be anticipated ; but, if pro- perly cared for, we have never found mere age to appreciably \ deteriorate a good gelatine film. With dry -collodion plates the ■ ease was altogether dift'erent, as by the gradual decomposition 1 <»f the collodion itself, frequently aided by the nature of the i orgHnifier or so-called preservative, a constant change or decom- { position was going on. At the time the plates were made the only developers prac- tically available or, at any rate, in general use were alkaline pyro and ferrous cxalate, and we presume that both these,, hut certainly the former, in its various modifications, had been tried before the plates were put away as faulty. These were again tried just in order to ascertain if the original qualities of the films remained, and so far as the mere density, or rather want of it, was concerned, they answered directly to the character appended to them ; that is to say, while very rapid — rather remarkably so — and perfectly clean in working, they were absolutely useless for printing purpt>ses, owing to the want of vigour. This was more particularly the case with ferrous oxalate, and the best result — if a scarcely appreciable difference in density can be so called — was obtained with pyro' and potash. The' first of the more modern developers tried because the first in order of introduction was hydroquinoiie, and with thin a very decided increase of density was produced at first attempt, and with an ordinary formula. But the improvement was accompanied by an alarming reduction in sensitiveness, not, be it understood, a mere prolongation of the time required in development — a not unusual feature of hydroquinone — but a direct impossibility, with a given exposure, of obtaining any- thing like the same amount of detail, even though the develojj- ment was extended over a couple of hours. Nor was this the only difference in the behaviour of hydro- quinone. Instead of the clean, delicate, image produced by pyro or iron, the newer solution gave in every instance a coai-se and patchy effect, which at first sight seemed to arise from stains, but which on closer examination proved to be due to the fortn of irregular development for which hydroquinone is remarkable, especially with paper positives. We have no record of the composition of the particular films under treai- ment ; but, as at the period of their manufacture chloride of silver was not an unknown or unusual component of the negative emulsion, it is very probable that the presence of some chloride would account for the irregularity. Eikoncgen and amidol both failed in producing any appreciable increase of density as compared with pyro, indeed the former appeared, if anything, inferior in that respect. As regards sensitiveness, there was no apparent falling off as in ' the case of hydroquinone. As, after ringing the changes on the variations of the different formulre, hydroquinone proved to be the only one capable of any increase of density, but accompanied, as we have described, by loss of sensitiveness and other defects, it occurred to us to try a double or combined development in which hydroquinone played the part of intensifier. Mixed solutions of hydroquinone with pyro'and eikonogcn have beeit employed with a certain amount of advantage — especially in America — in cases where on« or other alone has failed to pro- duce adetiuate vigour ; but, before trying the mixed solutions, they were applied separately, pyro, eikonogen, and amidol respectively being first applied with a view of getting out the detail, and hydroquinone following as the intensifier. The be- haviour of the particular batch of plates under this treatment was peculiar, for it was found in every instance that the solution first applied stamped its individual quality upon the image, and the subsequent application produced literally no 162 THE BRITISH JOURNAL OF PHOTOGRAPHY. [March 17, 1893 effect. In other words, hydroquinone failed entirely as an intensifier when thus attempted. In another set of trials, in 'whicli the hydroquinone was used first in order to get a certain amount of vigour, while eikonogen was subsequently applied to bring up the detail, the effect of the first solution was the only one that was apparent ; for the hydroquinone not only still exhibited its want of energy or capability of bringing out detail with a short exposure, but actually prevented the eikonogen doing so — in fact, it appeared to act in very much the same manner as a strong dose of bromide. Such being the effect of separate applications of these two solutions, it was not considered worth while to try others in conjunction with hydroquinone in the same manner. The mixed solutions were, however, finally tried, and, while there was no practical advantage apparent in the case of pyro and hydroquinone, pyro and eikonogen, or any combination of amidol, eikonogen, and hydroquinone, in conjunction gave a decidedly better result, so far, at least, as the production of density without loss of sensitiveness was concerned. So far as that, indeed, was concerned, all was as it could have been wished ; but unfortunately the irregularity in development which characterised hydroquinone alone still prevailed, though to a lesser extent. The point, however, to be specially noticed is that the retardent action of the latter disappeared when it was used in the presence of eikonogen, although it existed when the two were used separately. Another peculiarity in the action of the mixed solution upon the old sample of plates under experiment was the production of what at first appeared to be dense fog, but which proved to be a deposit of very fine loose matter that was easily and per- fectly removed by rubbing the film with the finger. This, together with the irregularity in development, we take to be due, in great measure, to the composition of the films, for on repeating the last experiment (with the mixed solution) with a sample of commercial plates rather wanting in vigour, the beneficial action in securing additional density was again notice- able, while the other peculiarities were altogether absent. It seems, as far as we have gone, that any advantage there is to be gained from a combination of developers will be in the use of mixed as distinguished from separate solutions. This being the case, it will be desirable to inquire how such mixed solutions will keep, especially as the practice seems to be gain- ing ground of using the same quantity of solution for a succes- sion of plates. ♦ LENS FOG. Of all subjects important to the production of clear, crisp photographs, that which forms the title of this article has had perhaps the least attention. Yet, in its many forms, it is the cause of as many defective negatives as any that can be named, short of those inevitable to absolute want of experience. The one example most familiar is that of flare, which, as all know, arises from the diaphragm being improperly placed ; but the number of lenses still sent out by makers of position in the optical world which yet suffer frqm this defect is, to say the least, something remarkable. It is merely localised fog, arising fi-om the lenses, and so embraced in our title ; any lens possessing the defect should be returned to the maker at once upon its being noticed, with, if possible, a print taken by its means and showing the flare. Another potent fog-producer is the presence of a single scratch on a surface of one of the lenses. Many plates may be taken, and the effect of the scratch be imperceptible, yet on some particular day, under conditions favourable to the performance of this defective portion of the instrument, it is possible for a negative to be hopelessly ruined ; the vagaries a scratch is capable of indulging in are occasionally most singular. The most favourable condition is seen to be when the lens is exposed to a great flood of light ; and, again, will fog be pro- duced wlien taking interiors if a strong beam of light impinges upon the lens from some unnoticed side-light — awindowor other- wise. We have seen fog brought about by a reflected light from some bright object in the field of view striking the surface where the scratch lies. Jt is, however, but to draw attention to the evil to discover a remedy. If the scratch be painted over with opaque paint — black varnish is as suitable as any- thing— all danger is obviated. The performance of the lens will not be interfered with, except to the extent of reducing the light passing through it. As a scratch whould be an ex- ceedingly large one that would occupy the hundredth part of the surface, it follows that the consequent loss of light in such case — a hundredth — is not worth discussing. Akin to this cause of fog is that condition brought about by careless use and handling ; the surface is covered with a multitude of fine, almost invisil)le, scratches, and these, when the lens is flooded with light, will cause the image to lose con- siderably in brilliancy and crispness. It is remarkable that we do not hear more of such defects than we do, for the careless- ness with which some operators dust and polish the lenses of their objectives is simply appalling. When a lens is damaged in this way, there is no remedy but to send it to the maker. It is a mistake ever to attempt, as is sometimes recommended, to polish it up with rouge, putty powder, itc. If the polishing is sufficient to remove the scratches, it means removing the surface to the depth of the deepest scratch, which, slight though it may be, is quite sufficient to alter the original curves, on the correctness of which the performance of the lens depends. Another frequent example of lens fog is brought about by the « brass mounting near the lens showing througli the original coat- 1 ing of black given to it by the maker, the result being that the rays of light entering or leaving the lens suffer reflection or refraction at the bright part, and cause veiled images ; for it must be remembered that a very slight amount of light is sufficient to act upon the plate. When this reflected light falls upon the shadows, as it does equally with the lights of the picture, it may easily be sufficient to ca,use fog, at a time, too, when the real cause may have remained unnoticed. When large portrait lenses are in question, this wearing away of the dead black of the instrument is usually seen in the outer rim of the back cell. Let any one, with camera set ready for exposure, remove the ground glass, insert his head under the focussing clotli, and examine the state of the lens. He will often be surprised at the amount of light reflected from tliis rim, and it is self-evident that all extraneous light visible inside the camera to the eye placed in such a position must fall upon a plate, and produce a greater or less amount of veiling, according to its intensity. But both for portrait and landscape work, where the quicker kind of lens is used — that in which the posterior and anterior compounds are separated some considerable distance — there arises a frequent cause of fog, before which this last-mentioned cause becomes absolutely insignificant. We refer to the state of the inner surface of the brass mounting. Whether from the gradual entry of dust through the diaphragm slot, the interior being often thus coated ;. whether from the. original Maroh 17, 1893] THE BRITISH JOURNAL OF PHOTOQRAl'HY. 168 coating being insufficiently matt— a by no means infrequent condition — or from occasional wiping of dust from tiio interior, it very frelic tliere is piven a reproduction of the portrait of his cook, taken by Daguerre. It was one of the first photographs he executed, and was presented to the Acad.'mie des Sciences in 1844 hy M. Arago. Antidote for Cyanide of Potassium. —The records of i^uicides in recent years show that cyanide is still the fashionable poison amonff photographers. Dr. Kossa say.s that permanganate of potash transforms the cyanide into cyanate, which is said to be inoffensive. Antiquity of Amidol or Diamldoplienol. — According to an article in the Wochenblatf , diaraidopenol or amidol, both as chlor- hydrate and sulphate, was originally prepared by T. Gauche in 18C9 by the reduction of dinitrophenol by means of iodide of phosphorus Since then the body has been extensively studied, Hemilian, in ISTo, showing that by the reduction of the dinitrophenol the salts of diaml- dophenol were formed, and, not as Gauche thought, those of diamido- benzole. Photo^rapblc Properties of the Salts of Cerium. —According to the Moniteur, Messrs. A. & L. Lumiero have obtained photographs by the aid of the salts of cerium. Cerium^ it is said, forms two series of compounds like iron and manganese, the eerie and the cerous, the eerie salts having the property of being reduced to the cerous state under the influence of light. It will be remembered that Messrs. Lumiere have taken advantage of a similar property of the manganic and cohaltic salts to produce positive impressiona The SynoBCope Wide-ang'le Xur.v.vl Photographic Almanac, for it contains, according to his letter, statements on a particular page not to be found there in any other copy. G, Wat.moi-oh WKBSTEn, F.C.S. JOTTINGS. The unalterable ass who beats the drum for the S/ioptieian and Spectacle- se/lers' Gazette seems to be in doubt as to whether the owner of the nom-de-plume at the end of these " Jottings'' is a lady or a gentleman. It is so agreeable to the anonymous journalist to be taken for one or the other, that 1 am peculiarly p.iined to have to deny the compliment of a choice to my critic — who is neither. Mr. Jones — the only Jones, I should think— has been sriving the Halifax Society his ideas on landscape or tourist photographv. " He did not believe in the long-focus camera when on tour." Why ? Has Mr. Jones never experienced the want of a long- focus lens out of doors 'i " The best way to store films or plates after exposure was to place a thin sheet of non-actinic paper between every two plates." Why nora-«f^««'e paper ? " He considered the legs of the tripod .... a great nuisance." Where does the " nuisance ' come in I' and why not include the camera, the dark slides, and the lens in the same category, Mr. Jones, or use- what the Irishman would call a one- legged tripod .^ "He had often been annoyed by crowds of people standing round when about to expose, and recommended as a remedy that one's wife should be .sent round with the hat, which he con- sidered would be effectual in making them move off.'' If / were among the crowd, ray readiness to move otf woulci be largely governed by the lady's ])ersonal gifts ; but I i-hould like to have the ladies' views on the suggestion. On the whole, Mr. Jones's photography is superior to his gallantry — but not very much. I hear a meeting of Exhibition Judges is to bf held, with a view, I suppose, of arriving at a common basis of action for their future giudance, and the preparation of rules to be observed by societies holding exhibition*. The ridicidous airs and graces which several judges have given themselves lately proves that there is as much need for rides and regulations for tlieni as for societies and individuals; and I hope therefore that the .search lights of the photographic press will be turned on their proceedings, so that the game of mutual admiration does not go too far. It seems to me that in late years the principal qualifications for a judge at photographic exhilntions are two, namely, (1) that he should have produced a few passably well- selected and composed photographs, indifferently focussed and exposed. Mardi IT, 1893] THE BRITISH JOUHNAL OF PIIOTOORAPIIY. ieJ5 and printed to look as much unlilco ft " photosraph " as possible ; and (2) that ha should have foisted lengths and lenjfths of nebulous twaddle ou Art — with a cupital A — on the readers of the photo- graphic papers. The worst of it is that people of this kind pet .^o imbued with the notion that tlieir way of imikiiij; pictures by photT- graphy is the rijfht one, that any one who thinks otherwite, and proves the faith that is in him by exhibiting, stands very little chance of an award against those who prefer to look at nature through a ring stop. Contact photographs, with the_ tones broken up by the interposition of ruled gratings between the negative and paper when printing, are, to my mind, so distinctly effective, that I should not be surfised if the public, being gently inclined thereunto by a little of the push and assiduity with which, alas ! so few modern photographers are en- dowed, did not take kindly to them, and the of 1 -expressed aspiration for a new style of portrait, which has appeared in these pafes of recent years, be fulfilled. During a brief visit to the States last year 1 saw several grated photograplis, produced, I think, by a New i'orlc photographer. They were on albumen paper ; but I can conceive that on bromide or platinotype, where, as a rule, the contrast between the lights and the shadows is more accentuated, much more effective results can be secured. The preparation of suitable screens is no ea«y matter for the ordinary photographer, and it would, I think be worth somebody's while to take the matter in hand commercially and supply screen negatives with a small variety of grains. But I would not give much for Mr. W. Lindsay's idea of securing the grain bv sifting powdered emery on a gelatine surface, however much it mio-h t effect a resemblance to photogravure on albumen or gelatino-ehloride. It seems to me that more evenness and regularity of grain would be likely to be obtained by mechanical ruling, while I am doubtful of the artistic success attending any attempt to impart the dominant features of Xphotogravure to a " surface" print. The great Amateur versus Professional controversy seems to die a hard death. No professional photographer worth his salt need be alarmed at the progress of amateur photography, for if a man who devotes his days and nights to photography, and has the wholesome knowledge that his daily slide and the Sunday's dinner depends upon the measure of his application to his profession, cannot acquire a ran"-e of ability fifty times greater than the non-professional photographer who simply follows the art as a hobby, then has he mistaken his vocation, and is only fit for the hod. The sneering at amateurs as such by several of your recent correspondents strikes me as in the highest degree puerile. I applaud Messrs. Allison, of Belfast, whr, on March 3, write ,vou that they are endeavouring to make a little money out of amateurs by iasxiing a scale of charges for the use of dark room, developing, &c. ; but I hav<} no patience with W. Tippinsr, who, on March 10, appears to yearn for a new style of picture which' amateurs could not " imitate." As if that, per 'se, would popularise portrait photography with the general public one tithe more than at present ! If your correspondent wants a process which amateurs do not work, why does he not turn his attention to the neglected processes which you described a couple of years ago, among which he will find .several admirable methods suitable for portraiture ? By the way, I wonder if Mr. Byrne, Mr. Winter, Mr. Vanderweyde, Mr. Crooke, and Mr. Warneuke care a rap how much amateurs "imitate '' them. Not likely. _ Advance, Australia I An enlargement, fourteen feet mx inches by six feet three inches, for the Chicago E.Khibition, quite snuffs out the big enlargements which have recently been e.'tecuted in this country for the World's Fair. I wonder if anybody buys— and pays for— these mammoth pictures ? A man who could afford space for hanging them could afford to have big paintings, I suppose, and would have them. I like enlargements— " not too much enlargement, just enlargement enough "•— but, when they are measured by the yard, I fail to see their beauty or utility for ordinary purposes. Still, " sweet are the us»s of advertisement." Cosmos. GEOBGE WASHINOTON WILSON. One by one, and in on increasingly rapid sequence, the men who mad« photography are passing away. There is no one whose name has ever keen associated with all that is excellent in the art department of photography that stands so high as that of George Washington Wilson, of Aberdeen. When he first issued his singularly beautiful stereoscopic views, it was at once universally felt that a real artist had arisen, one wlio would aid in elevating landscape photography from the somewhat low state of mediocrity in which it existed. In his pictures were concentrated the highest development of artistic beauty and technical skill, and they became models for imitation ; .ind it is to this, in many Cises slavish, imitation that we owe a marked and rapid progress as soon as his gems of art came to be known and studied. " Quite Wilsonian '' was, and still is, a term frequently applied to photographs having a certain style of technique. Imitation is rightly said to be the sincerest form of flattery, and we know of some who did not disdain to follow Mr. Wilson's footsteps in such a literal fashion as, having one of his views in hand, and observing the relation of one por- tion of the scenery to the other, to eventually by this means discover the identical spot where his camera had been planted, and there also plant their own tripods. In early life Mr. Wilson studied in the Art School, Edinburgh, and for some years he followed the profession of miniature painting, an avocation in which he attained a considerable measure of success. His reason for abandoning that art is rather remarkable. We learn from a local paper that just as he had begun to make a name for himself photography was discovered, and the impression became common that portrait painting aa a profession was doomed. Mr. Wilson was apparently of that opinion, and threw aside palette and easel for the camera. He became one of the pioneers in photography, and was among the first to apply it to land- scape. It is said that he had the honour of taking the first photograph of the Queen and the Prince Consort at Balmoral in 1850. His services were frequently requisitioned at Balmoral after that ; and one notable group of Koyal personages includes the late Emperor Frederick (then the Crown Prince of Prussia) at the time he was courting the Princess Boyal, and so gratified was the Prince with the character of the work produced IGG THE _JBRITISH JOURNAL OF PHOTOGRAPHV. [March 17, 1893 by Mr. Wilson that he commissioned him to execute a series of water- colpur sketches representative of Deeside scenery for presentation to the Princess Koyal. When passing through Aberdeen in the Jubilee year, the deceased Emperor (still Crown Prince) paid a visit to the premises of the Messrs. Wilson, and, recalling the circumstances referred to, entered into a long and friendly conversation with the deceased. After commencing business as a photographer he made numerous ex- peditions to notable parts of Scotland, and his views obtained on these occasions became widely celebrated. They were taken by the wet- collodion process (which he worked in a little portable tent), and in which he was an adept. By this he secured admirable instantaneous effects •with fine skies. About seven years ago he retired from the active pursuit of photography, leaving three of his five sons to manage the large business now established. This, within the past few days, has been formed into a limited company, the necessary negotiations to that end having only been brought to a termination on the 9th inst, on the morning of which day he ^ied very suddenly at his residence. Queen's Cross, having been in town on business the day previous. He was seventy years of age when the sad «vent occurred. When he retired to bed the previous evening he was in his usual health, but at one o'clock in the morning he had an epileptic seizure and expired soon afterwards. After his retirement from active business, he once more took up the lirush, and painted the portraits of several citizens of eminence. Mr. Wilson was a member of the Chamber of Commerce, and had represented one of the wards of the City in the Town Council. He was also a Director of several companies in Aberdeen. It is needless to speak in terms of eulogy of his works— that has been done by the world during a long term of years; and through them, although now dead, he yet speaketh. As we have said, he was seventy years of age at his death, which took place on March 9. He is survived by a widow, four daughters and five sons, to all of whom we tender our sympathy. The portrait we here give is a striking likeness, and was among the last that was taken of the eminent photographic artist. ON THE PRODUCTION OF BLACK AND WHITE NEGA- TIVES BY MEANS OF ARTIFICIAL LIGHT. III. The great aim in black and vrhite work being to produce negatives having much contrast, i.e., clear glass for the blacks and the utmost density for the whites, it follows that the greatest care requires to be observed in the matter of dfivelopment. A worker, however, will often be puzzled to account for the varying behaviour of the plates he exposes on what at first sight appear to be almost identical subjects. There is, however, a great difference in the behaviour of various samples of white paper. This can be easily proved by taking a sample of snow white, upon which some design or handwriting has been effected by means of Indian ink, and alongside of this place, say, a sheet of printed matter from any ordinary book or publication, and exposing the plate on both simultaneously. On development a con- siderable difference may he apparent in the densities. There is a golden rule, however, to follow in all cases, viz., to stop development Before any reduction in the blacks begins to take place. This is not by any means a difficult thing to do, but it means the utmost care must be taken to give a full exposure, but not by any means an over- exposure for the method of development it is intended to adopt. Full density is seldom or ever acquired by development alone. Provided, however, sufficient attention has been given to the proper lighting, and a small stop used in the lens, with a correct exposure, a very considerable amount of density will be easily acquired before there is the least sign of any veiling over in the blacks or transparent portions of the negative. This must be carefully looked for, and development arrested the moment the least signs are noticed. A worker will now see how necessary it is that the utmost pre- cautions be taken to guard against any strong light entering the camera, except that which is conveyed to the sensitive plate by the lens and which forms the image. This I pointed out in a previous article. Sometimes unsuitable lenses are employed for copying. No lens should be used that conveys any fight to the sides of the camera, or, in other words, that considerably more than covers the size of the plate being used. When it is considered that exposures of minutes' duration have frequently to be given, it will be at once obvious that any reflected light from the sides of the camera would be certain to cause deterioration to the transparency of the negative. This is a very frequent cause of defect, even in ordinary work ; hut in black and white subjects it is one of the most insidious defects met with, and when it occurs no perfect results can be obtained. Whenever, after due attention has been given to the matter of cor- rect exposures, &c., it is found that degraded negatives are still being produced, this defect should be looked for. I have said that it is but seldom sufficient density is acquired by development alone. This means that all, or nearly all, negatives intended for black and white prints require to be intensified, and this being so means that the utmost care should be bestowed in the treat- ment of the plate during development. With so many excellent formulae for development in the hands of every worker, it might seem unnecessary for any one to recommend one in preference to another, because it is quite possible for a worker to turn out as good negatives by a certain formula, the working of which he daily practises and is therefore conversant with, as any one else can do by a different formula entirely. This undoubtedly is so in the all-round working of photography, but I find in black and white work I have succeeded in getting quite different results by the employment of a formula different in many respects from that used for other classes of work. Some years ago I was forcibly strupk, when reading a formula which I think was first given to the world by Mr. Leisk, that it appeared to me to be just the right one for black and white negatives. I can strongly recommend this. Here it is : — Make up the pyro by adding nine ounces of saturated solution sulphite to one ounce of pyro, then add sixty grains of citric acid ; label A. Dissolve four ounces of carbonate of soda, 288 grains of sulphite of soda, forty grains of bromide of ammonia in thirty-two ounces of water; label B. Attention must be given that these quantities are carefully weighed. In conjunction with this formula, a clearing bath should be pro- vided, as follows : — Add two drachms of strong acetic acid to one pint of water. Most workers of any experience will readily understand that some plates require considerably more pyro to gain extra density than others; therefore, practice alone will show the quantity of pyro to use to each ounce of soda solution. As a rule, however, it will be found that when the developer is very strong in pyro and bromide, and the exposure has been so regulated for such, the best results are got. I have frequently gone as far as two drachms of pyro to each ounce of soda, with an addition of bromide of ammonia over and above the quantity in the formula. With a good isochromatic plate, this will yield plenty of density to allow of complete opacity when the plate is intensified. The great advantage of this formula is that it never stains the plate. When it is seen that the utmost range of density has been acquired without any reduction in the blacks, the plate is sponged gently by means of a plug of cotton wool with a quantity of the clearing solution. This will remove all developer from the surface. Do not wash the plate at this stage, but, after sponging off the developer, place it straight- away in the bath of clearing solution above given. This prevents any staining that would probably occur were cold water applied to the plate, the surface of which still contained some portion of the pyro developer. The plate should he kept in the clearing bath for at least some minutes. From the clearing bath the plate is well washed under a running tap, and is then fixed m freshly mixed hypo. If strict attention is paid to these particulars, a beautifully clean bright negative is the result. A dirty or previously used fixing bath should be avoided. It may not be generally known, but a discoloured fixing bath will stain a plate, provided it remains in such only a very short time. Some workers use a clearing and fixing bath made up by adding to about twenty ounces of hypo solution of proper utrength two ounces of saturated solution of sulphite of soda, to which has been added one drachm of hydrochloric acid. This is a very useful fixing bath for ordinary work, and keeps the bath free of discolouration for some time after being used ; but I fancy I never get such good clean results when the intensification stage is reached, after plates liave been fixed in such. An alum bath also is better dispensed with when plates have to be intensified. Some workers advocate the use of a gallic acid bath for the exposed plate previous to development, and claim that by its use the utmost amount of density and contrast is obtained. I know one worker who speaks very highly of its use in conjunction with a certain brand of plates, but I can confidently [recommend Mr. Leisk's formula, which I have described. It is cleanly in its results, and yields bright and sparkling negatives. So much for the formulae. Now let me refer to a very important factor in development that is seldom or ever taken into consideration even by experienced workers. I refer to the important influence a March 17, 1898] THE BRITISH JOUItNAL OF PHOTOGRAPHY. 167 variation of temperftturo in the developing solutions has in the resulta obtained. We often hear expressions of dissatisfaction made nboi.t this or that plate being bad, or this or that developer being all wrong, or the light must have been awfully bad to-day, or some other such ejaculations having reference to the difficulty experienced in getting a plat« to develop up with the usual amount of detail; or it may be the other way about, such as, after getting into a certain way of working with some particular brand of plates, all at once things get into a different groove, and quite a change comes over the behaviour of the plaie, although, as far as can be judged, everything has been conducted just as before. I am quite sure this puzzle has bothered many an amateur who looks upon himself a« a full-Hedged worker, and yet somehow they cannot discover the reason of the different behaviour of the plates. To those having experience of this, and who would like to solve the problem, let me suggest the following experiment:— Take two plates, and expose them on any given subject under exactly the same conditions in every respect ; proceed into the dark room and mix up sufficient developer in one cup to develop both plates, they being placed in different dishes. Proceed to develop with the formula I have given one of the plates with the developing solu- tioil at a temperature of about 38° Fahr. JIark how slow the development proceeds, and how for a long time only the high lights put in an appearance, and in many instances, even with a full ex- posure, the utmo.st difficulty is experienced in bringing out the shadows, the result being a negative violent in contrasts, with every appearance all through of being under-exposed, although such has not been so by any means. Now take the other plate, which has been exposed under exactly similar conditions, and with the other porticm of the developing solution exactly the same proceed to warm the porcelain developing dish by placing it in hot water, and whilst the dish is warm pour in the developer, so as to raise its temperature. Now place in the dish the plate and proceed to develop, and mark what a distinct difference at once becomes apparent. There is now no talk of under-exposure, but, on the contrary, the plate will very possibly come rushing up and sliow every sign of being over-exposed. Here, then, in the matter of altered degrees of temperature of the developing solution, we have a considerable power for ringing the changes in the way of getting violent contrasts when desired, and in the production of negatives from black and white subjects. We can do much in the way of keeping clear glass for the blacks by a judicious use of developing solutions of a low degree of temperature, at least, for a portion of the time the plate is being developed, and if desired, the temperature can be raised by merely flowing the solution into another dish, which is standing in warm water. In my hands this alteration of the temperature of the solution ilvring (hvelopment has proved a sroat boon in many cases, for, by a judicious use of such, not only can density be got to begin with, but the amount of detail that will eventually be brought out is sometimes quite surprising. When copying ordinary photographs, or other similar subjects, it is very necessary to get pluck and vigour in the high Lghts before detail is out, and it is got better by this means than any other I know of. In winter-time, much may be done by warming the developing dishes, for in such weather as we get up here in Scotland, where we have a long spell of cold weather, often for weeks together the developing solutions will stand as low as ■iS' Fahr., and sometimes even lower ; whilst in summer-time a supply of iced water, to cool the dishes at the start, helps wonderfully in gaining various ranges of tone in the negatives. T. N. Abmstbong. "SPIRIT PHOTOGRAPHY," WITH REMARKS ON FLUORESCENCE. [London and Proyincial Photographic Association.] Tbe presence of smoke may be considered as implying the existence of flame. Spirit photography, so called, has of late been asserting its existence in such a manner and to such an extent as to warrant competent men making an investigation, conducted under stringent test conditions, into the circumstances under which such photographs are produced, and ex- posing the fraud should it prove to be such, instead of pooli-poohlng it as insensate because we do not understand how it can be otherwise — a position that scarcely commends itself as intelligent or philosophical. It in what follows I call it " spirit photography " instead of psychic pho- tography, it is only in deference to a nomenclature that extensively pre- vails, and not as offering a surmise from any knowledge of my own as to what is matter and what spirit, or the distinction between mind, spirit, and matter, for in truth I don't know. I approach the subject merely as a photographer. Origin of " Spirit "' Photoobaphy. Before I proceed, a few words on the origin of spirit photography may not be out of place. In March, 1801, W. H. Mnmler, the principal engraver in the employ of Bigelow UroB. & Eennard, the leading jewellers of Boston, when whiling away an idle hour as an amateur photographer, had a form other than that of any one present developed on his collodion plate. He surmised that it arose from an image having been previoualy on the plate, and its having been imperfectly cleaned off. Subjected to a more thorough cleaning, the form again appeared more strongly marked than before, and he could offer no other explanation than the one given. 1 1 got noised abroad through the press that a spurit had been photographed , and although Mumler strove to suppress the misrepresentation, as be regarded it, yet be eventually succumbed to popular demand, and took two hours a day from his regular work, devoting them to photography. This he had to extend to the whole of each day, entirely discaiding his regular profession. Many men of eminence sat to him, most of whom he did not know at the time. He seems to have encouraged his sitters is the adoption of such test conditions as they deemed satisfactory. The figures that usually appeared on the plate with the sitters were, if I rightly inter, those on whom the sitters' minds had been set. That eminent portrait photographer, Mr. Wm. Black, of Boston, so well known all over the world as the inventor of the acid nitrate batb, undertook to investigate the bona fides of Muraler's methods. Through a friend, who had just previously sat and obtained a figure, Black offered fifty dollars if Mumler would operate in his presence and obtain a picture. Invited to come, the acute Black critically examined camera, plate, dipper, and bath, and had his eye on the plate from the moment its preparation began until it was sensitised and locked in the dark slide, removing it himself from the camera and carrying it into the dark room, wiiere, on dcvelopraeot, a figure of a man was seen leaning on B.'s shoulder. Black was wonder- stricken, and got away the negative, no charge whatever having been made. Mumler now claimed publicly to be a spirit portrait photographer, and as such he eventually opened a studio in New York, having previously satisfied Silver, Gumey, and other photographers as to the gconineness of his claims, never hesitating to operate in their galleries if required, and with their apparatus and chemicals. Mumler was arrested in New York ; whether on the ground of witchcraft or of endeavouring to obtain money under false pretences, I am at present uncertain, but his trial was the sensation of the day, and namerous witnesses were examined. He was honourably acquitted. Some Investigators of the Subject. In this country, several who are amateur photographers have investi- gated this subject with more or less success. These include some F.R.S.'s, scientists, artists, and'others. I question whether any have so persist- ently done so as the late Mr. John Beattie, of Clifton, and his friend. Dr. Thompson. Mr. Beattie was a skilled professional photographer of the highest eminence, who sometimes, prior to his death, had adopted the views of the spiritualistic school. The figures he obtained on his plates were much blurred in outline, some being misty in the extreme, I possess some two or three dozen of these taken by, or in the presence of, Mr. Beattie, whose intelligence, honesty, and powers of observation no one would venture to doubt. Many such photographs are claimed to have been produced by Hudson, a professional photographer, formerly of the Holloway-road, and I submit for examination a work by the late Miss Houghton, containing fifty-four of Hudson's spirit photographs. There are many ways by which, assuming the genuineness of only one ot all spirit photographs hitherto produced, the spurious article may be made even better than any alleged real ones I have yet seen. A plate secretly impressed previous or subsequent to being placed in the camera fulfils the condition ; so does one at the back ot which is placed a phos- phorescent tablet in the dark slide. Pressure on the surface, such as by that of a Woodbury relief film, also causes a developable image ; in short, trickery in a whole variety of forms may and has been impressed into the service. PnOTOGBAPHINO THE INVISIBLE. The higher department of fluorescence may with success be employed. Here is something to which believers in the visibility of spirit forms to a camera are quite welcome. At the time, and apropos of the Mumler trial in New Y'ork, I wrote that a good many absurd things have been said pru and con on the subject ; but a writer in the latter category, who asserted that anything that is visible to the eye of the camera, and thus capable of being depicted by photography, must therefore necessarily be visible to the human eye, was surely ignorant of that important branch of physics popularly known as fluorescence. Many things are capable of being photographed which to the physical eye are utterly invisible. Why, for that matter, a room (visually dark) may be tnll ot the ultra-violet rays ot the spectrum, and a photograph may be taken in that dark hght. Objects in a room so lighted would be plainly visible to the lens of the camera — 168 TnK BRITISH JOURNAL, OF PHOTOGRAPHY. [March 17, 1893 at any rate, they could be reproduced on the sensitive plate, while at the same time not an atom of luminousness could be perceived in the room by any person possessing ordinary or normal vision. Hence the photo- graphing of an invisible image, whether it be of a spirit or a lump of matter, is not scientifically impossible. If it reflect only the ultra-violet rays of the spectrum, it will be easily photographed, although quite invisible to the sharpest eye. d Again, Cromwell F. Yarley, F.E.S., well known as one of the most eminent of electricians, says {Eclectic, June, 1871), when passing a current of electricity through a vacuum tube, the results of which were indicated by touches of light about the poles : " In one instance, although the experiment was ean-ied on in a dark room, this light was so feeble that it could not be seen, and the operators doubted if the current were passing. But photography was at work, and in thirty minutes a very good picture was produced of what had taken place. This," he says, '' is a remarkable fact ; indeed, it borders on the wonderful that a phenomenon invisible to the human eye should have been, so to speak, seen by the photographic lens, and a record thereof kept by chemical agency. It is highly suggestive, and we may anticipate that it will be turned to good account by practical philosophers." Fluokescence. Some very striking phenomena in photographing the invisible may be produced by the agency of fluorescence. Figures depicted upon a back- ground by one or other of certain substances I shall presently name, although invisible to the eye, may become visible to the camera. Of these, the best known, although not the most effective, is disulphate of quinine. Such a solution, although to the eye it is colourless like water, is to the camera as black as ink. Fill three phials respectively with water, quinine, and common writing ink, and you have two whites and one black ; but photograph them, and you have two blacks and one white. The camera has reduced the transparent quinine solution to the colour of the ink. Those of you who may care to experiment in this direction, please take notice that the quinine must be acidulated with sulphuric acid, and that hydrochloric acid, even a small trace, will destroy this property. Among other substances that are fluorescent, or that change the refrangibility of rays of light, are mineral uranite, cer- tain salts of uranium, canary glass, alcoholic solution of chlorophyll, ajsculine, tincture of stramonium seeds, and of turmeric. There are others known to be still better, but my experiments in this direction are yet too incomplete to warrant my even indicating them. Let me for a moment enter the realm of speculation, and assume that there are really spirits invisible to the eye but visible to the camera and to certain persons called seers or clairvoyants only. Might we not suggest that there is some fluorescent compound in the eyes of such persons not present in those whose eyes are normal, and that it is to this they owe their seeing powers ? Some of you may probably be aware that Dr. Bence Jones and other philosophers have actually established the fact of such fluorescent substances being found in some eyes. May this throw any light upon the recognised fact of certain animals being able to see in the dark? When the subject of fluorescence is more thoroughly investigated (it is a discovery of Sir D. Brewster, who was followed by Herschel and Pro- fessor Stokes, and is as yet but of yesterday), we may hope for a vast accession to our knowledge of subjects as yet very slightly understood. At the Bradford meeting of the British Association for the Advance- ment of Science, in 1873, Dr. Gladstone, F.E.S., demonstrated before the Mathematical and Physical Section what I have said respecting invisible drawings on white cards having produced bold and clear photographs when no eye could see the drawings themselves, and I brought away back to London these photographs, and, for aught I know, may have them still. A Lxnif's Joke. To prevent this disquisition from being too dry, I will here introduce a fanciful sketch I wrote apropos of Dr. Gladstone's demonstration at the time mentioned: — A mischievous young lady oi scientific proclivities who attended the meetingof the British Association, and who was addicted to practical joking, listened attentively to Dr. Gladstone's observations upon the properties of quinine referred to, and having carefully noted the discussion that followed, reasoned within herself thus : If solution of quinine can make invisible marks upon paper which will come out black in a photograpli, it ought to do the same when applied to the skin. So she procured some of this solution, and upon her fair brow she painted with it a death's head and cross bones. These, of course, were invisible to human vision. Thus pre- pared, she went to a photographer to have her portrait taken. All went right until the operator went in to develop the plate, when she soon heard an altercation between the photographer and the attendant boy, in which it ,was evident that the latter was being charged with having coated an old or dirty plate. A second negative was taken, with this result, that the operator, after bestowing a puzzled, affrighted look at the lady, rushed downstairs to the principal of the establishment. Both returned to the dark room, and a third negative was taken, when it became evident that intense excitement was being produced in the dark room. After an excuse to the lady about there being electricity in the atmosphere which had affected the chemicals, she was requested to sit once more. Scarcely had the plate been developed when both photographer and assistant rushed out from the dark room, pale and excited, and explained that on the brow of the sitter in each negative was emblazoned the insignia of the King of Terrors. The negatives were produced, leaving no doubt of the fact. What was to be done ? The sitter hinted something about not being disposed to be made a fool of by one who she was satisfied was a spirit photographer, and that she, for one, would not allow herself to become the victim of such absurdity. This upset the equanimity of the photographer, who expressed his earnest conviction that she was an emissary and personal friend of the common enemy of mankind. " I shall look in again to-morrow," said the lady, in her sweetest tones, " if you promise not to play any of your silly ghost tricks upon nie." "Not for ten thousand worlds," said the artist, "shall you ever set foot within my studio again." " Oh," she laughingly rejoined, " I shall drop in through the roof and visit you some day when you are disengaged ; " and with that she departed. "I knew it!" gasped the photographer. "I felt a sulphurous odour the moment I came near her. Send immediately for my friend, the Eev. , and get him to offer prayer, and free the studio from the evil influences remaining after a visitation from one whose feet, although clad in boots, would, if examined, be found to be cloven." Some Personal Expekiments. For several years I have experienced a strong desire to ascertain by personal investigation the amount of truth in the ever-recurring allegation that figures other than those visually present in the room appeared on a sensitive plate. The difficulty was to get hold of a suitable person known as a sensitive or " medium." What a medium is, or how physi- cally or mentally constituted to be different from other mortals, I am unable to say. He or she may not be a photographer, but must be present on each occasion of trial. Some may be mediums without their being aware of it. Like the chemical principle known as catalysis they merely act by their presence. Such a one is Mr. D. of Gla-igow, in whose presence psychic photographs have long been alleged to be obtained. He was lately in London on a visit, and a mutual friend got him to consent to extend his stay in order that I might try to get a psychic photograph under test conditions. To this he willingly agreed. My conditions were exceedingly simple, were courteously expressed to the host and entirely acquiesced in. They were, that I for the nonce would assume them all to be tricksters, and, to guard against fraud, should use my own camera and unopened packages of dry plates purchased from dealers of repute, and that I should be excused from allowing a plate to go out of my own hand till after development, unless I felt otherwise dis- posed ; but that, as I was to treat them as under suspicion, so must they treat me, and that every act I performed must be in ijresence of two witnesses, nay, that I would set a watch upon my own camera in the guise of a duplicate one of the same focus — in other words, I would use a binocular stereoscopic camera and dictate all the conditions of operation. All this I was told was what they very strongly wished me to do, as they desired to know the truth and that only. There were present, during one or other of the evenings when the trials were made, representatives of various schools of thought, including a clergyman of the Church of Eu^'land ; a practitioner of the healing art who is a fellow of two learned societies ; a gentleman who graduated in the Hall of Science in the days of the late Charles Bradlaugh ; some two extremely hard-headed Glasgow merchants, gentlemen of commercial eminence and probity ; our host, his wife the medium, and myself. Dr. G. was the first sitter, and, for a reason known to myself, I used a monocular camera. I myself took the plate out of a packet just previously ripped up under the sur- veillance of my two detectives. I placed the slide in my pocket, and ex- posed it by magnesium ribbon which I held in my own hand, keeping one eye, as it were, on the_sitter and the otlier on the camera. Thero was no background. I myself took the plate from the dark slide, and, under the eyes of the two detectives, placed it in the developing dish. Between the camera and the sitter a female figure was developed, rather in a more March 17, 189/11 TIIE BRITISH JODRNAL OF PilOTOGKAl'Iiy. 160 pronoanced form than that of the sitter. The leus was a portrait one of short focas, the figure being somewhat in front of the sitter was propor- tionately larger in dimensions. I submit this picture. It is, ai you see ft lady. I do not recognise her or any of the other figures I obtained as like any one I know, and from my point of view, tliat of a mere investi- gator and experimentalist, not caring whether the psychic subject were embodied or disembodied. Many experiments of like nature followed ; on some plates were ftbnormal appearances, on others none. All this time Mr. D. , the medium, during the exposure of tlie plates was quite inactive. After one trial which had proved successful, I asked him liow he felt and what he had been thinking of during the exposure. Ha replied that his thoughts hal been mainly concentrated upon his chances of securing a corner seat in a smoking carriage that night from Euston to Glasgow. How- THE Psychic FiorBES Beiiavkd. If the precautions I took during all of the several experiments, such as those recorded, are by any of you thought to have been imperfect or incomplete, I pray of you to point them out. In some of them I relaxed my conditions to the extent of getting one of those present to lift out from the dark sUde the exposed plate and transfer it to the developing dish held by myself, or to lift a plate from the manufacturer's package into the -dark slide held in my own hand, this being done under my own eye, which was upon it all the time ; hut this did not seem to interfere with the average on-going of the experiments. The psychic figures behaved badly. Some were in focus, others not so; some were lighted from the right, while the sitter was so from the left ; some were comely, as the dame I shall show on the screen, others not so ; some monopolised the major portion of the plate, quite obliterating the material sitters ; others were as if an atrociously badly vignetted portrait, or one cut oval oat of a photograph by a can-opener, or equally badly clipped out, were held up behind the sitter. But here is the point: not one of these figures which came out so strongly in the negative was visible in any form or shape to me during the time of exposure in the camera, and I vouch in the strongest manner for the fact that no one whatever liad an opportunity of tampering with any plate anterior to its being placed in the dark slide or immediately preceding development. Pictoirally they are vile, but how came they there ? The Stkbeoscopic Cajieka isj Use. Now, all this time, I imagine you are wondering how the stereoscopic camera was behaving itself us such. It is due to the psychic entities to say that whatever was produced on one half of the stereoscopic plates was reproduced on the other, alike good or bad in definiiion. But, on a careful examination of one which was rather better than the other, and which is now about to be projected on the lantern screen for your examination, I deduce this fact, that the impressing of the spirit form was not consentaneous with that of the sitter. This I consider an important discovery. I carefully examined one in the stereoscope, and found that, while the two sitters were stereoscopic per -w, the psychic figure was absolutely flat. I also found that the psychic figure was at least a millimetre liigher up in one than the other. Now, as both had been simultaneously exposed, it follows to demonstration that, although botli were correctly placed vertically in relation to the particular sitter behind whom the figure appeared, and not so horizontally, this figure had not only not been impressed on the plate simultaneously with the two gentlemen forming the group, but had not been formed by the lens at all, and that, therefore, the psychic image might be produced without a camera. I think this is a fair deduction. Bnt still the question obtrudes. How came these figures there ? I again assert that the plates were not tampered with by either myself or any one present. Are they crystallisations of thought 7 Have lens and light really nothing to do with their formation ? The whole subject was mysterious enough on the hypothesis of an invisible spirit whether a thought projection or an actual spirit being really there in the vicinity of the sitter, but it is now a thousand times more so. There are plenty of Tycho Brahes capable of Bupplymg details of observations, but who is to be the Kepler that will from such observations evolve a law by which they can be satisfactorily explained ? In the foregoing I have confined myself as closely as possible to narrating how I conducted a photographic experiment open to every one to make, avoiding stating any hypothesis or belief of my own on the subject generally, and it only now remains to exhibit the results, bad and fraudulent-looking as they are, on the screen. J. TB.UIX TA.XL01U OX DIVERS Sl'BJECTS. Tbk Parobak. I BUi'POSR that DO leas tlian a hundred or so inreDtor« have exclaimed, on reading the account in the last Bnixisii Joub.val oi' Puoto- OHAPHY of the " Panoram," " Why, I have had that in my head ever so long." I am one of the hundred or so, and congratulate the practical inventor for carrying' out an idea which occurred to me the first time I uwd tlie Eastman roll-holder, having in my possesion an old Johnson I'antascopic camera, which, in the days when I had time to use it, gave me great satisfaction. Of course, it brings up the question of perspective again, and will make di-scussion hot. It will be impossible to make the general public accept the perspective of the " IVnorara " as correct, for the presentation of a line known to be straight as a curved one will be at once denounced as a falsehood ; but the fact is that, in the case of horizontal lines, only that one which is on a level with the eye appears to it as a straight linn, the lines above that level being bent down at the extremities, and those below it bent up ; and in their finest temples the Gieeks, who had no idea of scientific per8])ective, recognised this phenomenon, and, to give the buildings greater apparent dimensions, exaggerated the perspective effect by making the horizontal lines curve slightly, in the same ntnae that the effect of perspective made them .seem to curve. The reason of it is apparent. If you stand opposite the central column of a long colonnade, the apparent height of the more distant columns diminishes in an increasing ratio, and, if the most distant were twice as far away as the central one, it would appear half the height ; and this is the true perspective, as it is the true aspect of any natural object. Scientific perspective is a pure fiction, and the action of rectilinear lenses is so arranged as to confirm this fiction. It renders perfectly the facts on any gi-en plane, but in no case gives the actual appear- ance to the human eye. As the Editor ha< shown, a sphere in extreme perspective becomes an ovoid, while the capital of a column is, in the case of a very wide-angle view, distorted most unnaturally, while to the eye, looking direcfly at them, they are of the same shape as the central ones. rEHSPECTIVE. In talking of the relation of perspective to photography, whetlier the scientific or real perspective is to be treated of, we must remember that there is a complicatiun not easily adjusted in the equation, which is the fact that the photograph itself has to he seen in perspective, no matter how near it is held to the eye. Suppose, for instance, a photograph taken with a rectilinear lens of fifteen-inch focus of a facade of a building presentinir a line of columns, the point of view being opposite the centre of th- pounds of sulphur had been emitted, and these, having no outlet, had acted on the free silver, converting it into sulphide of silver. I can only advise shippers, therefore, not to pack sensitized paper in sealed tubes, but to roll it up in blotting and brown paper only. To those photographers who, like myself, only use small quantities of paper at a time, I say, cut it up in suitable tizes, and pack it between blotting^ paper, treated with carbonate of soda, as has been so often recom- mended. Packing Plates. Whilst on the subject of packing, let me rtquft't plate makers not to pack their plates with sheets of "papier Jcse.jh " or other paper between them. I have tried several brands of plates packed in that manner and before I have had them many months paper marks have appeared and rendered them useless. On the other band, plates packed with a slip of thin card at the edges deteriorate very slowly, and any packing marks appear at the edges only. W'hen I purchiise plates here I like to see the word " sUpped " written on the label. A word too on the subject of pacldng plates in tin foil. A carefully- prepared plate when new should give no trace of " light fog," and any chemical fog produced by energetic forcingshould be even over the plate. But plates on keeping show fog first at the edges, and then this gradually creeps over the plate according to the time it has been stocked. A great part of it may be removed by gentle friction, but prevention is better than cure, and for some time past I have had all plates for astronomical use packed in tinfoil with most beneficial results. I have met no plate that does not sensibly degenerate with time, but now my complaints on that score are reduced to a minimum. By the way, it is hardly fair far a plate manufacturer to advertise that they supply plates to the Cape Observatory, on the strength of the occasional purchase of a few boxes at "a local dealer's. Our stellar plates have for some time past been specially prepared for us by Mawson & Swan, and are a model of even coating and clean working, with rapidity and fine grain. Landscapk Photogbaphy at the Cape in 1892. Two novelties during the past year are worthy of special notice under this heading. We had a severe winter, which extended far into the summer months. Ice was found on Table Mountain, although we had but little frost below, and on the mountain a little sleet fell ; but on the distant mountains to the north and east of the peninsula snow fell in abundance, and at Worcester, a town fifty miles from Cape Town in a straight line, a party of climbers as- cended to a height of 6000 feet, where one of their number — Mr. Isaac Meirig — took some photographs, which are perfectly Alpine in character, and that, too, at a time of the year when we are usually experiencintr the commencement of the summer heat. The other novelty consists in the views of the Zambezi Falls, brought down by Mr. Ellerton Fry, who exposed a large number of plates there under considerable difficulty, the chief trouble being the showers of spray that obscured his lens, nearly spoilt his camera, and fogged his plates. Only one in every twenty plates he exposed does he consider a perfect success, but these are pretty numerous and unique in their way. Indecent Photoghaphs. A much-needed law was passed last session stringently prohibiting the sale of indecent photographs, not that we are fastidious. The photographs prohibited are seldom the work of Cape photographers, for the ordinary run of photographs of natives cannot be classed under the above heading. They may be made indecent, and in that case their sale would be rightly stopped ; but the photographs aimed at are those displays of nastiness frequently sold at foreign seaports. Port Said has an unenviable notoriety for such works, and so have some VVestern ports of North and Central America, and most of the Southern American ports as well. When going on shore at Guayaquil in South America in 1883, we strolled into a photographer's and asked to be shown some photographs. lie opened two large drawers of — well, we blushed, and it takes something to make men do that, whilst the photographer was surprised to find that we wanted landscapes, and had very few to show us. Xow that a law has been passed here on the subject, it is to be hoped that on my next visit to England I shall have less annoyance with the Custom authorities. My experi- ence at Plymouth has been that, on the arrival of the steamer from South Africa, the appearance of anything photographic in one's March 17, 1803] THE BKITISH JOURNAL OF PHOTOGUAidY. 171 boggajjo lias furnished occasion for rigid cross-examination and a strict search for anything nasty. PEnMANKNCY OF PuiNrs— GELATINE versHs Albumen. An instructive siglit here is to watch the show-cases put up by photof^raphers in the principal streets. You see a group of sparkling landscape specimens, which you stop to examine. A week or two later you notice that the blazing sun is effecting n change in them. Soon the should-be whites have turned to an intense gamboge, then the shades appear mealy, and at last out comes a batch of new speci- mens. Printing-out paper is liaviiig a run hero, and it was soon noticeable tliat photographers were taking advantage of it in hopes of obtaining greati!r permanency. And yet the other day I noticed that the gelatine prints were going like the rest. I remarked to a member of the profession that the gelatine prints were as little per- manent as albumen, but he differed from me. " Look on this group of prints and on that," he remarked. " Printed at the same time, exposed outside together, got damp together, as witness the water stain on the cardboard. Yet, you see, the albumen are fast going, and the otliers are almost unchanged." Under the circumstances, it i« difficult to come to any conclusions. Time alone and the collated exjieriences of many will tell. C. Ray Woods, Photographic Assistant at the Cape University. LIGHT, SHADE, AND PICTURE COMPOSITION. Befork the Aston Society, on March 9, Mr. C. T. Cox. head master at the Birmingham School of Landscape Art, delivered a lecture on Light, Shade, and Picture Composition to the members and friends of the above Society. In his opening remarks he said he knew that much nnkindness existed between devotees of the camera and lovers of the brush, and that many of the latter always tried to depreciate work of the former ; and before commencing his lecture he should like to say that lie was no party to such feelings — in fact, he considered the photographer etiual to the artist, however high, and that in many cases the camera could produce effects that would be otherwise beyond the skill of an artist to obtain ; in short, he thought the two should work together. He then dealt with laws relating to chiaroscuro, and showed in many ways how the laws relating with art were equally applicable to photography, and how the violation of such laws led to failure. The members present were here asked to take down the nine rtlles governing the proper representation of a picture, and were as follows : — (1) Principality, (2) Kepetition, (8) Continuity, (-1) Curvature, (.5) Inter- change, ((1) Contrast, (7) Radiation, (8) Consistency, (D) Harmony. After explaining the first principle, he showed, by means of specimens, how far the law of repetition was carried out in the works of Rembrandt, Turner, Edward Watson, and others ; how the chief image was again represented by a similar but minor study, not competing with the chief object of interest, but only repeating it. Then, again, continuity, as in the case of the outlines of mountains, pillars, trees, &e., would also he seen not competing with repetition, but only repeating it. The speaker here asked who had not noticed the graceful curves of motion of the hnman figure, the exquisite curvature of the movements of body, the dainty toss of the head, and from these he went to those of Cader and Snowdon, and pointed out that the whole of nature presented these curves to the users of those valuable twin lenses, the eyes. He had seen and painted old Welsh cottages whose chronic curvature of the backbone of tlie roof and tumbledown gables lent a charm to the whole scene. Contrast and interchange were then fully dealt with, effects in the former being oliiefly obtainable in April, when days of tender light and soft, flickering shade were always present ; and here the lecturer showed bow the general rule of contrast was laid down in the works of Buskin, viz., " the shadow thrown was always deeper than the shaded side of the i object throwing the shadow." Again, most of the famous works of Claude Lorraine were all based upon the division of his canvas diagonally into light and shade, with an interchange of botli from one to the other, and the larger the picture the greater was the halt-tone of each introduced. Rnskin asserted that the shadows in photography always appeared three times as dark as they were in nature, but the lecturer said he had adjudicated in photographic exhibitions in which he had seen shadows depicted far truer to nature than could have been portrayed by the brush, owing to their transient character. Relating to consistency, Mr. Cox asked who would think that "a lovely sylvan scene — a poem without words, one that draws out the soul and appeals for response to every- thing that is beautiful in the mind," would be consistently represented in a thunderstorm? he said that "rocky crags and frowning dark ravines" would be more consistent with the battle of the elements. Radiation and harmony were next dealt with, and herein he advised that photographers should follow the lines of the old masters and obtain an oval character for their views, although this was often exaggerated, as in the works of Bonnington, one of which was shown in which the clouds appeared as if placed in order to fulfil the ovality, as it were. He said, if the camera wreen were divided medially through the sides, and an ellipse sketched round the points of contact, we should have a gnide to good piotote, making if we avoided placing objects of interest in the comers or on the margin of the diagram. He (the speaker) concladed with some splendid remarks on clouds, those things which bothered photographers, and more especially artists, but things which were invaloable to the pro- duction of a good view. Finally, he was pleased that Aston had formed a photographic society. He wished them every soccess, and offered to give advice gratis to any member at any time that they may feel they would like to have bis opinion or criticism. MANCHESTER PHOTOGRAPHIC SOCIETY'S EXHIBITION, This Society, whilst not following the practice which has now become common amongst kindred associations of inviting exhibits from the general body of photographers, was able to display a very pleasing and interesting collection of photographic work, fairly representative both of the progress made by individual practice and the development of new processes. The Exhibition was open on March 9 and 10, and was well attended both days. An improvement made in the hanging of exhibits over previous years perhaps in a manner added to the satisfactory character of the show ; still, as a rule, the contributions were of excellent quality. Prizes were offered for the best exhibits in various classes ; but for the instantaneous nenre pictures and home portraiture the result wm dis- appointing, especially as regards the first-named, it being either an indication of the waste of energy displayed on " snap-shots," or the un- favourable conditions during the past two years for this class of work, for only one member sent specimens. In portraiture, too, a good set by Mr. J. Wood was alone, so that in these two classes prizes could not be given. The i/enre pictures were only two in number, and neither very striking as compositions. Mr. J. Wood's Taking Milk to Market gained the prize ; the title, as far as " taking milk," was well expressed, but the desti- nation of the said milk not very obvious. Mr. Higson's picture. Father Adam, was a good photograph, but not very expressive. Two classes for Landscape (over half-plate and smaller sizes) were, as a matter of course, well represented, two bits of local scenery, Morton Bottoms, by Mr. J. Wood, and In the Bollin Vallei/, by Mr. W. G. Coote, taking the prizes. Interiors were all good, Lt/me Hall Entrance, by Mr. M. W. Thompstone, being adjudged first. Stereoscopic and lantern slides were not as numerous as the number of workers in this class could warrant, Mr. J. Higson, with stereoscopic transparencies, and Mr. H. M. Whitefield, with lantern slides, taking first places. The enlargement class was very prominent both by number and quality. The Judges highly commended two pictm'es exhibiting very opposite treatment, one a bromide, by Mr. J. Brier, At Tirol i, being a well-defined, perfect enlarged reproduction of the negative ; the other, also bromide, a Norwegian harbour scene by Mr. ¥. Edwards, a very clever and artistic enlargement of a hand-camera exposure. Mention might also be made of Mr. E. G. Wrigley's seascape enlargements for brilliancy. The scientific or experimental photography class was responded to by Mr. B. Robinson and Mr. H. Smith, the former with a frame of photo- micrographs of great technical excellence, and the latter by perhaps the most interesting exhibit in the room, namely, the treatment of gelatino- chloride printing-out paper by short exposure and development. The results of evident patient experiment were shown by a number of prints, different tints (from red to blue-black), being obtained by varying the exposure and development, no gold or otlier toning being employed. The Judges were Mr. Geo. Perkins (artist), Mr. J. W. Wade, and Mr. J. W.Leigh. The platinum, gelatino-chloride, and bromide were the processes used by nearly all the exhibitors. THE CENTRAL PHOTOGRAPHIC CLUB. The Executive Committee appointed by the public meeting on March 6 has already got to work, with the result that suitable premises and Club rules are under active consideration. Another meeting will be called in a few days to consider the propositions of the Committee. The Hon, Secretary pro tern, has received a large number of applications for membership, particulars of which will be sent in due course to the applicants, ♦ ©ur iBUitorial tHatlt. Rough's Impeoved " Excelsior" Hand Camera. Ingenious in every way as Messrs. Rouch's now well-known " Ex- celsior " hand camera is known to be, the march of improvement has still further added to its usefulness and excellence. It has now a sliding as well as a rising front, and a rack and pinion adjustment allows of lenses of varying foci being used, an index scale being, as heretofore, placed on the top of the instrument. In addition to two 172 THE BRITISH JOURNAL OF PflOlGGKAPHi'. [March 17. 1893 finders, there are spirit levels on two sides — a great convenience. The camera may be used on the stand with slides and a focussing screen, and the firm's well-known changing- back can be employed instead of slides. To the chansing back is now added an indicator, so that by simply touch- ing a small lever at the side, the number of plates exposed may be seen at a glance. Tlie camera we saw (made expressly forMr. E. Hawkins, a successful hand-camera worker) was fitted with the Thornton- Pickard focal plane shutter, and this in such a neat way as not per- ceptibly to increase the bulk of ihe instrument. Altogether, the Excelsior remains the perfection of a practicable, workmanlike instrument, that must be a pleasure for the photographer to handle. Marion's Cartridges for Developing and Fixing. Messrs. Marion & Co., Soho-square, have submitted to our notice pyro and soda developing cartridges, together with similar cartridges for fixing which they have recently introduced. The various contents of these form an impalpable powder which dissolves almost imme- diately after being thrown into water. The pyro-soda cartridges are in form of plain glass tubes closed at one end and well corked at the other, two of these forming a complete dose for ten ounces of water. As might be sui mised, the contents of one is pyrogallic acid, that of its companion being sulphite of soda and carbonate of soda. The proportions of these are so accurately adjusted as, with the above quantity of water, to form a perfect developer. The fixing cartridges, like the others, contain the active agent in form of a fine powder ; and. according to whether they are to be used for negatives or prints, so is the quaiitity of water determinable. For negatives, the contents are dissolved in five ounces of water, while for prints ten ounces form the correct quantity. This is a most excellent form in which to keep these necessary agents, not alone convenient for those who go to the country or sea- side during the summer, but also for those who stay at home and like to have things ready to hand. AnDRKSBn's " DiAMIDOPHKNOI. " AND " COMBINED ToNING AND Fixing Bath." Messrs. ArthurSchwarz & Co., the agents, have sent us samples of diamidnphcnol which, used with alkali in the proportions of the formula given, develops rapidly and cleanly, and renders the density well. The toning and fixing cartridges should prove extremely useful — they impart a deep but pleasing rich black tone to prints. 0F,tHimfi of Siotittit^* MEETINGS OF SOCIETIES FOR NEXT WEEK. » ■ 1 Date of MeotiDR. | Name of Society. Place of Meeting. March 20 \ Charing Cross-road, W.O. Asso. Stndio, Nethersrat«, Ihiudee, Fillebrook Lecture Hall 180, West Regent-street, Glasgow. Mechanics" Institute, Leeds. Greyhound Hotel, Richmond. Hanover Hall. Hanover-park, S.E. Club Room, Colonnade Hotel. 376, Coldharbour-lane, Brixton. City Chambers, Gandy-st., Exeter. 206, Mare-street, Hackney. Mechanics" Institute, North-street. Canonbury Tower, Islington, N. 9, Gauze-street, Paisley. The Assembly Rooms, High-road. Anderton"s Hotel, neet-8treet,K.C. The Studio, 15, Cambridge-arcade. Charing Cross-road, W.C. „ 20 „ 20 „ 20 „ 20 „ 20 Fiilcbrook Atlienicum .. Glaauow & West of Scotland Am. Hastine's an'l St. Leonards „ 20 „ 20 „ 21 „ 21 Birmingham Photo. Society ... „ 21 ;; 21 „ 21 „ 21 „ 21 ,. 22 „ 23 „ 22 Sonthport „ 23 „ 23 „ 2i HuU 71, Prospect-street, Hull. Rooms, 15, Dawson.street, Dublin. Champion Hotel, 15, Aldersgate-st. The Lyceum, Umon.street,01dham. „ 23 Ireland „ 2:1 „ 23 „ 24 Cardiff .. „ 24 Public Hall,George-8treet,Croydon. „ •^■^ „ 24 "The Palace," Maidstone. Ohiswick School of Art. Chiswick. 71, Prospect-street, Hull. „ 24 „ 25 Hull PHOTOGRAPHIC SOCIETY OF GREAT BRITAIN. March 14,— The President (Captain \V. de W. Abney, F.R.S., D.C.L.) in the chair. Messrs. E. Collins, E. J. 0.arwood, H. W. Hughes, W. E. Pond, T. P. W.itson, and the Duchess of Sermoneta were elected members. The North Surrey, Hastings, Derby and Manchester Photographic Societies, the Croydon Camera Club and the Photographic Section of the Chester Society, were admitted to aftiliation •{ the Society. The Hon. Secretauy announced receipt of a supplementary commuiiicatiou from Colonel Waterhouse on Gaiacol, of which he had tried a fresh sample. It had distinctly weak developing powers, and it wan quite possible that it was not a developer, although practically it was one apparently inversely to its purity. He had also tried other derivatives of creosol, and tliought their developing power might be due to oxidation products. A minute quantity of impurity might impart developing powers. Naturalistic Photography. Owing to Dr. Emerson having sustained a bereavement, his paper on A^atumlistic -Photography -waa Tesid hy '^iH. T. R. Dallmbvkr. la the paper (which we shall give in exteiiso on a future occasion). Dr. Emerson said that two years ago his researches into the subject of vision and persjieotive drawing were responsible for tlie withdrawal of his book. When betook \\[i jibotography he was told by all that if the photographic observer closerl one eye anil placed the other eye at the focal distance of the lens ho would see tlie picture true to uiiture. He felt that this was not tlie case, and he maintained that the sharp pliotograph was not true to nature ; hence years of long and inky warfare. Opticians were right from the mallieinatica! stand- point and he from the physiological. He had laid it liown that truth to nature was obtained by throwing the background out of locus. There- was no connexion here between want of sharpness or jiinhole pictures ; it was a deliberate and conscious act to be modified .tcfording to circmn- stani'es, .and not a hap-hazard doilge. He had found his m^tiiod of focussing justified by psychology. As to what was trae in nature l'ro:ii tlie visual stand- point, he thought the tele-photo lens a most useful tool to jpiit into the hands of the decorative photographer. The position he ami Mr. Goodall had taken up in their pamphlet'on drawing and vision was still unshaken. Tliere was no absolute truth to nature from the visual standpoint, for as c-;icli man's sight was different, the only absolute truth to nature was in his own vi,-w of it. From the mathematical standpoint there was an absolute standard, which was the sharj) photograph. Having saul that the shajics of things, such a- table-tops and wall-paper patterns, are perspective distortions, the tran.-ition from one ti> another being infinite and continual, he said that it was evident that no photo- graph gives things as we see them with two eyes; sonie photographs gave results nearer to what we saw than otlvers, but were not ii.itnraiistic photo- graphs. How true must the photograph be that it may be considered naturalistic ? It must be true in fundamentals to the point of illusion, that is, a man's boots mtistnot be twice as big as his head. He did not consider photography was an art, it was a mechanical jxiwer. Its |results wrre sometimes more beautiful than art, but were never art ; just as nature is sometimes more neantiful than art. Photography was a mechanically recording reprcsmtation of nature. Having definepeared to have changed his fundamental views as regards jihotography, but not as to his method of working. The paper correspondeil with the tendency of thought at the present time in regarding the beautiful as sub- jective rather than objective. Mr. Emerson's figure of an artist's ideal changing during the progress of a picture had considerable interest as bearing on the subjective idea of the beautiful rather than the objective. There were undoubtedly a great many ideas in the paper wliich were quite new. Mr. Andrew Pringlk did not understand the jiaper, but he was perfectly willing to believe that it was extremely able. The subject was a great deal discussed — perhaps too much to be profitable, and it contaiaeil many truisms which were as old as the hills. Mr. W. E. Debenham defended mathematical persjiective as the only true perspective, and also thought that an artist's idea of sliarpness, in contra- distinction to the photographer's, meant harshness of outline. Mr. Emerson, had said that a great deal of pretentious rubbish had been written about art ; they might retort and call this paper Einersonian rubbish.. Dr. Emerson had said that a reiiresentation of nature on a plane surface was impossible. Were they then to condemn paintings, and were stereoscopic views to be aciepted ? The Rev. F. C. Lambert .said the paper wanted three months' careful read- ing, it cont.ained so much that was old and true, and so much th.at was debat- able. He was not at all sure that he nmlerstood the greater part of it. Dr. Emerson h.ad, it seemed to him, taken up the same position as .Mr. Pennell— that because a ]ihotographer places between his l>rain .and what ho sees a machine, the product had no stamp of individuality. The mere question of tools did not affect individuality. Mr. BiRT Acres disputed the view that half a dozen photograiihers taking the same view would produce identical results, as each would have his own idea as to how the view struck tliem as a picture, and their ideas would differ as to brilliancy or softness of results. -Vgain, lie did not think the best workei-s in photogr,apby called themselves "artists," though they produced artistic March 17, 1803 1 THE BRITISH JOURNAL OF PHOTOGRAPHY. 17? result), ne (lihers. Mr. 'P. It. D.M.i.MKYKB said the subject involved very d»ep study. Differential focussiiiR lind come forwanl a (rrent deal since Dr. Emernon first laid it iliiwn. It apprariMl to liini (Mr. Oallmeyer) that Mr. Debenliam bad gone away froin tlif ii':il iiitiMil of tlii' jiaper. as Dr. Kiiierson was not clisini*(in){ niatbcniatical iwrspective. I'sycliolopy was not a science yet, but we ilid not see tilings in niatheinatic.nl perspective for psychological reasons. He thought the term decorative a gooil one in reaard to pliotoiiraphy. Kev. K. (;. I.AMBKUT agneil with .Mr. Dallnuyer ii% to the iniportanca of linking pliysiology and psycliolo^'y togetlier to appreciate workK of art. As to the iKse of the term decorative, it seemed to liiia all pictures were decor- ative. Mr. PniNcl.E, in the course of further observations, said that, in spite of all Dr. Emerson's chani;es of position, no person had a right to deny that photo- graphy owed a great ileal to him. He had done a great deal towards turning the attention of photographers into an improved artistic line. The results of his work were licfore them irow, and though many of his jiupils and ilisciples had thrown iiim ovcrboanl. the fact remained tliat he had inau;;urateainters, and he iliil not see the necessity for it, as photograph coidd be cjrried ou without reference to ]>ainting. The Hrksiuknt, in closing the discussion, .said that be himself was only a plain maker of ''photographic maps," but it seemed to him that, what- ever might be the onicoine ol' the [laper. Dr. Emerson himself w.is the outcome. Whether the fuzzy .school would last was a matter for tlie jiuljlic to say. He (the I'residenti would continue to take sharp photographs, as ho thought the fashion for them woidd come back again. Votes of thanks wefe passe"XISO explained that it had originally been intended to have had the iihotographs taken in a photographer's studio, but the photographer had withdrawn from the experiments on the ground that the latter were dangerous. The photographs, therefore, were taken in the drawing-room of a bouse in Dalston. Mr. EvKKiTT a.sked whether that house wa.i inhabited by a spiritualist, or any medium, or any one of .spiritualistic tendencies ? Did Mr. Taylor go as a sceptic I Mr. Taylor .said that he went with a perfectly open mind. Mr. E^BBITT pointed out that in the paper Mr. Taylor said that he con- sidered himself as acting as a detective upon those who were present when the photographs were taken. Mr. Taylor explaineerateil to produce those Images. They miuht cjill thorn by any name whii I; ' • nmend itself to them, but he (.Mi. ' ' ' i ing^ would call then mIs, excarnated human Vwinir«. H- Im jiictureft »j)irit !■ . Iwcause they were portraits of !'■ i i,ad cast off the earthly tal>ernacle. Mr. f. A. KKliKiB saiil they were bound to believe Mr Taylor's statementA ; but, as practical photograiihers, though the pictures shown miijht lie spirit ]ihotngTa)dis, he tnoiight tney g.ave them the idea of cut-out print*, but aa U> who cut them out he did not know and did not care. Mr. Gi.KVBiNMSi! remarked (ironicjlly) that he was the gentlenian who "cut them out." Mr. DowKEV regarded the photographs as a "clever trick." Mr. EVEKITT remarked that Mr. Ulendinning had drawn attention to the capacity of Mr. Taylor as a witness, and they could not have a fietter repre- sentative of photographers for such ex|>erinents ; but Mr. iWeniliiininghadgone a step further, ami said that Mr. Tavlor. having witnessed all the persons in the room, they were entitled to infer that the ai>)iearances v.ere due to " other persons " pre.sent. He (Mr. Everitt) would say that nobody h.-ul a riiht to infer the presence of "other persons." It was no doubt true that Mr. Taylor had got images he did not expect to tind, but to .say th.it they were due to " other persons " present was another matter. If they wer^ entitlcl to infer that thostj appearances were due to jiersons they did not know, they were also entitled to infer that they might lie due to other physical iihenomeiia they did not know. They might be due to copies of other photographs which had got on the plates in some unaccountable way. Then as to the ii>om^all the other conditions but this were under Mr. Taylor's control. It was a pity it did not suggest itself to him, with each successive exposure, to remove to anotlier room. By varying the conditions for each photograph, he might have tracefl out the conditions under which they were produced, and have hail some means of arriving at a conclusion. Mr. Taylor's experiments liad been vitiated to a large extent by his not having the whole of the conditions under hi« own control. Mr. A. Cowax said that about fifteen years ago— before dry plates were used — a laily of title and a member of the Stock Exchange came to him in London and asked liim to go to Mr. Hudson witli them, to see if they coulil get some spirit jAotographs. He took jdates in.arked with a diamond. They went and paiil half a guinea for a sitting. The plate was coateing out positives on glass and exposing them on the negative before development. Mr. R. Child Bayley .asked wliether it had been appreciated that the "ghost photographs " hail only height and depth .- Mr, Haudox asked why the figures should have drapery ? Mr. Debexha.m objected to the assumption that the things were genuine because they could not be explained. Messrs. Maskelyne & Cooke's trick could not he explained by many people. Mr. EvEUiTT suggested that in future experiments a mirror should be place>» Irehind the sitter at an angle so that a photograph of the Imck of the spirit as well as tlie front should be obt.ained. Mr. .J. S. Teai'E, in regarl to the appearance of the photographs, .said any oue accustomed to the appearance of stump work would recognise some of the images as having been produced by the stump. They were not photo- graphs from nature in the first instance. In reply to a question as to whether, when he was out of the room developing, it would not have been possible for somebody to stamp an image in relief with fluorescent chemic-als ou the front of the camera, Mr. Taylor said it was impossible. Mr. Haddon pointed out that the spirits seemed to !» able to donble them- selves, as Mr. Taylor took a stereoscopic pictui-e with some on both halves. Oue of the " spirits " was at the back of the sitter, yet some of the high lights were on the sh.adows. He did not think any one would say th.ot the ultra- violet rays could pass through the human frame and a piece of wood. Mr. T. Shorter and Mr. .Maltby (visitors), Mr. .'\. Mackie, and other gentle- men, havin; spoken, Mr. (Jlcndinning s.aid he wouhl ei!-! " 'is inlliieuce to allow some members ot the Association to ii< .p the presence of the medium (Mr. D.) at a future .hate, :;: _ . :i closed with a vote ot thank" to Mr. Thylor for his poper. 174 THE BRITISH JOURNAL OF PHOTOGRA.PHY. [Maicb 17, 1893 North London Photographic Societj .—March 7, Mr. G. J. Clarke in the ■cliair.^ — Mr. A. E. Smith gave a demonstration of the photo-lithographic process. Explaining the necessity of a previous knowledge of carbon printing, he first developed a carbon print by single transfer. Some prints on bichromated gelatine films from wet-collodion negatives were then coated with photo transfer ink, soaked in water for a few minutes to soften the film where the light had not acted. The ink on the soluble part of the film was then cleared away, leaving the printed image ready for transfer to the stone, and the transfer thereof and method of printing were then explained. At the next meeting, at Canonbury Tower, on March 21, a Lantern Entertainment will be given in the reading-room. Hacloiey Photographic Society. — March 7, Mr. S. H. Barton in the chair. — The library was augmented by about a dozen more new books. Mr. J. 0. Grant recommended that the Society exhibits at the forthcoming Crystal Palace Exhibition, and, after it was carried, he said that the Committee would draw up and send a circular to all members. Mr. Beckett stated that the Committee had decided on purchasing two nine-inch lenses by Swift for the new lantern. Mr. Houghton presented the Society with a new form of carrier for the lantern. Members' work was then shown by Messrs. Cross, Sodeau (Arachoidus ornatus, ]ihoto-micrograph). Hudson (lantern slides), and Roder (two slides developed with amidol). Mr. GosLixa asked how many sheets of tissue paper were necessary to reduce or enlarge by (diffusion of light) in sun- light. It was stated that it would depend on light ; in any case, the paper must be put out of focus. Mr. Bbooker, of Hastings, then gave a lecture on Vlinckehea and Rye, illustrated by the lantern. Much care had been bestowed by Mr. Brooker on it, as it was verj' instructive and interesting to all, and that the slides were good goes witliout saying. Whilst the scientific side was treated upon, likewise the historic, the art side of photography was certainly to the fore, and a great treat was given to the Society. Mr. Brooker must be complimented ou the fine quality of his slides. South London Photographic Society, March 6, Ordinary Meeting, Mr. F. W. Edwards in the chair. — Mr. Leon Warnebke demonstrated his method of printing, developing, and toning gelatino-chloride paper. He said his process was somewhat similar to that used in 1848 for the preparation of waxed paper negatives before gelatine plates were inventecL While staying last winter in St. Petersburg he had to contend against an almost entire absence of light in carrying on photographic work. This led him to make certain experiments with Ilf ord P. 0. P. , Eastman's Solio, and Liesegang's Aristotype papers, exposing them for a short time, and then developing with gallic acid. The exposure of the paper could be made at night, using magnesium ribbon. He considered "Solio "paper the best suited for the process. If daylight was used, the paper could be exposed until the image was just visible, or until it was com- pletely printed out. Good results could be obtained either way. With a short exposure, development took a longer time. He then exposed a piece of Solio paper by burning about two feet of magnesium ribboTi in front of the negative. On examination, a faint image was found on the paper. He gave the following formula for development : — Water, 1000 parts ; acetic acid, 10 parts ; acetate of soda, 10 parts ; gallic acid, 5 parts. When dissolved, 10 parts of a ten per cent, solution of acetate of lead, after filtering, were added to the above. For development, 1 part of the solution to 5 to 10 parts of water were used. The print, on being placed in the developer, gained in detail and density, as if printed out in the ordinary manner. It was then jilaced in a dish of water, to which a pinch of table salt had been added to stop the action of the developer. Tlie print was then placed in a combined toning and fixing bath, composed of — water, 1000 parts ; hyposidphite of soda, 100 parts ; acetate of lead, 10 parts ; chloride of gold (one per cent, solution), '2(> parts. Uniformity of tone was very easily obtained. Toning could be stopped at any stage thought desirable. It was impossible to distinguish prints developed by this process from those printed, toned, and completed in the usual manner. The lecturer believed that the prints would be more per- manent than those prepared by the ordinary methods. In reply to ijuestions, he said a beautiful sepia tone could be obtained by using a platinum toning bath. A weak negative required a more concentrated developer, and a hard negative a dilute one, to obtain good results. He did not advise the use of separate toning and fixing baths. Lead acetate kept the whites clear, and did not afi'ect the permanency of the prints. Croydon Camera Club. — Third Annual Dinner. — The above was held on the 8th at the " Greyhound Hotel," when a con.siderable proportion of mem- bers met togetlier to enjoy gastronomical, oratorical, and musical entertain- ment. " Prosperity to the Club " was proposed by Mr. Charles W. Hastings in a neat and efl'ective speech, to which the President replied with a series of remarks which induced sustained merriment, the definition of "a human being" and an explanation of "why Diogenes tvae nut a dub man" being specially punctuated with salvoes of laughter. The violin solos of Mr. Joseph Beckwith were the most keenly appreciated of the musical items, and the healths of Messrs. Oakley, Tuckham, and White the toasts which were most enthusiastically received. Leicester and Leicestershire Photographic Society. — March 8. — The details of arrangements for the forthcoming Exhibition of the Society on March 22 and 23 were considered, the Hanging Committee elected, the Excur- sion Committee also arranged, and various other matters in connexion with the Exhibition received attention. Liverpool Amateur Photographic Association, March 9.— Mr. J. Sheard delivered his new lecture on Our Members of Parliament and Something about ■some of Them, illustrated by limelight portraits of present members of the House of Commons. The lecturer dealt in a racy manner with the personal reminiscences and peculiarities of about fifty members, and exhibited about 300 portraits, together with a reproduction of a number of lifelike silhouettes. "Pfeston Camera Club.— March 9, Annual Meeting, Colonel Oliver, J. P. ^President), in the chair. — The Secretary's report and balance-sheet showed a satisfactory state of affairs for a Society not yet two years old. It was decided to afiiliate with the Photographic Society of Great Britain in order to be able to procure the members technical instruction of a class superior to any that can be locally obtained, and at the same time to keep in touch with the chief centre of photographic activity. Colonel Oliver was unanimously re-elected as President and Mr. Frank Ketton took the combined postion of Hon. Treasurer and Hon. Secretary, the previous holders of these offices having resigned. Altogether the Club seems in a prosperous condition, and a successful season is antici- pated. Rotherham Photographic Society.— March 7. Dr. Baldwin (President) in the chair. — Tlie President and Hon. Secretary (Mr. Hemmingway) were ap- pointed delegates to the Photographic Society of Great Britain, under the Affiliation of Societies scheme. FORTHCOMING EXHIBITIONS. March 22, 23 Leicester and Leicestershire Photographic Society, Co, operative Hall, High-street, Leicester. Hon. Secretary- H. M. Porritt, 66, London-road, Leicester. April 5-8 *Croydon Camera Club, Braithwaite Hall, Wellesley- road, Croydo:.. Hon. Secretary, G. R. White, 55, Albert-road, Croydon. „ Kl-29 "Crystal Palace. Tlie Executive, Crystal Palace, S.E. „ 12-15 *Bolton Photographic Society. Hon. Secretary, J. E. Austwick, 10, Bushton-street, Bolton. „ 17-29 'Photographic Society of Philadelphia. Hon. Secretary, B. S. Redfleld, 1601, CaUowhill-street, Philadelphia, U.S.A. May4-€ *Forfai-shire Photographic A-ssociation. Hon. Secretary, W. J. Anckorn, West Port, Arbroath, N.B. * Signifies that there are open classes. RECENT PATENTS. APPLICATIONS FOR PATENTS. No. 4257. — "Improvements in the Condensers of Optical Lanterns." W. 1. Chadwick.— Z)aterf February 27, 1893. No. 4348. — "Improved Copying Camera for Photo-mechanical Work." A. Wybbant and W. GktABiM.— Dated February 28, 1S93. No. 4377. — "Improvements in Photographic Objectives." Complete speci- fication. A. B. PAWMti.— Dated February 28, 1893. No. 4378. — "A Flexible Temporary Support for use in Carbon or Pigment Printing." H. J. 'Rvwiov.— Dated February 28, 1893. No. 4520. — "Improvements in or relating to Photographic Processes." Communicated by W. J. H. Autou. A. J. Boult. — Dated March 1, 1893. No. 4578. — "The Pocket Portable Camera Bracket." F. W. Smethurst —Dated March 2, 1893. No. 4644. — "Improvements in and relating to Magic Lanterns, and to the Manipulation of the .'.ame." H. Simpson. — Dated March 3, 1893. No. 4672. — "Improvements in Apparatus for Exhibiting Photographs, Pictures, Advertisements, and the like." C. F. Vmi.— Dated March 3, 1893. No. 4692. — "Improvements in Photographic Objectives." Complete .speci- fication. P. Rudolph. — Dated March 3, 1893. Correspondents should never vyriie on hoth sides of the paper. No notice is taken of communicationt unless the names and addresseg of the vn'iters are given. MB. PEINGLE AND THE SANDELL PLATES. To the Editor. Sib, — I shall be glad if you can find space for what must constitute my reply to Mr. Andrew Pringle's opinions on the " Sandell " plates, as pub- lished in the Camera Club Journal of December last, and which I should have dealt with earlier but for a prolonged absence from home. These opinions, emphatic as they were (I am advised from several quarters) have tended to do the interests of the plates considerable harm ; but I should be first to admit that this result was altogether foreign to Mr. Pringle's intention. The experiments spoken of, although expressly de- scribed as of quasi-scientific character, have been regarded as having special interest for the practical worker, and, therefore, the necessity for my pointing out wherein I consider they are at fault. To fully discuss all the points involved in Mr. Pringle's arguments would require a lengthy dissertation on photographic theories and prac- tice, and a too great intrusion on your space, so I will endeavour to take the vital points only. Mr. Pringle seems certainly to fail to grasp the capabihties of 'the plates, and, were he an authority of lesser caUbre, I should be tempted to say there was a failure in his appreciation of the potentialities of the single sensitive film. Speaking of the photography of an interior, he says, " If the exposure bo only long enough to affect the upper film, the result is in no way March 17, 1893] THE BRITISH JOURNAL OF PHOTOGRAPHY. 175 different from that on an ordinary plate." This reminds me that it woald be more convenient if it was made manifest from the com- mencement that the position I take up rei^arding the platen is this : I assert and challpngo the contrary proof, that the plates are an absolate onro for halation from support reflection, in all practical photopraphy, and that their latitude in exposure is practically un- limited. Reverting to the interior, I submit that an exposure should not be quoted unless accompanied by the development given to render obvious the work done in the film or films during the ex- posure ; now, this is a most important item in considering the utihty of the new plates. Can Mr. Pringle imagine an exposure on any interior with a clear gloss window, admitting direct skylight, where the inside details arc even poorly rendered on the single film, where the light from window ha.s not gone throngh and through the film? he must have surely forgotten that halation is not unknown in snap-shot work. Mr. Pringle remarks in one place, he was surprised how little light passed through the single film ; it has been a matter of surprise to myself how much passes the film. On more than one occasion have I, in trying the experiment of stripping off the top film, found a printable image of the highest lights of a snapshot developed in the second film. It may be remembered that the finer emulsion of the latter is more amenable to development than the more sensitive one, and the image formed although apparently having a similar density, has a better printing value. To these qualities I attribute the characteristic softness of the prints from all exposures on the plate. Mr. Pringle also asserts that two or three times the exposure of an ordinary plate produces a failure with the " Sandell " plate, but if the higher lights of the snap-shot have so penetrated the plate how much more so will the exposures in question. I can quite understand his failures in this case if he relied on the preposterous operation (for practical work) of stripping or a total clearing away the upper image. But I think I can demonstrate that for this, and even a greater increase on the normal exposure, the image-forming capacity of the lower film is not a necessity ; and, leaving out of consideration latitude obtainable by developer modification, Mr. Pringle seems to ignore the constitution of the ordinary film, and treats of it as if it were a single molecule of silver haloid ; but I am sure on reflection he will agree with me that the latitude of the ordinary plate is really due to the superposition of many molecules, and also that only the molecules to a certain depth can be utilised effectively for the image formation, the remainder being simply serviceable as a screen. If development be pushed into this screen, the result is halation. Now, in the multiple plate, the whole of these molecules can be used up to the last line, and this I maintain will admit of a greater increase in exposure than that whish caused failures in Mr. I'ringle's experiments. Then, as to Mr. Fringle's joke (for surely it was such), when he spoke of the plates making him miserable, he said, " I do not think they are of any real value unless you give them enormous over-exposure." This is very comical, and smacks much more of a desk emanation than a dark- room one ; their latitude for prolonged development would seem to indicate superior advantages for the quickest exposures, as well as for the longest, and I can assure Mr. Pringle that he is mistaken in fancying that any intermediate exposure between maximum and minimum neces- sarily yields a failure ; the amount of exposure to be given, above the minimum allowable, by an experienced worker, depends entirely upon his own tastes, as to how much of his shadows he wishes to render. There is no occasion for the merest tyro to consult an exposure machine. Before I close, I must express my surprise that Mr. Pringle could have been informed that half-second /-64 under trees was the correct exposure for the plates. His informant could scarcely have consulted the pro- spectus sent with each box. In this he is directed to give the exposure of our table for the cyclist plate as a minimum. This, under trees, would be four minutes sixteen seconds ; and for landscape, with heavy foliage, three seconds. I do remember making the first of a series of experimental exposures with Mr. Pringle, and giving half second on heavy foliage, but I assure him he is mistaken if he understood me to suggest that I con- sidered this suflicient ; I did it simply to show the amount of reduction that could be effected in the film as a result of this short exposure. — I am. yours, Ac, J. T. Sa^jdell. Thornton Heath, March 11, 1893. CHEAP MOUNTS— A PLEA FOB QUALITY. To the Editor. Sir,—" Cheapness " is the tendency of the age. It is the natural right of every man, which no one can ever think of denying, to try to obtain what he desires for as small an equivalent as possibie. It is "im- possible to decide with mathematical exactness the relative value of things. Usage and competition fix what may be called the real or market value of the various articles, and still this fixed value may be doubtful according to the different prevailing circumstances. What is " cheap " from one point of view may be " dear " from another, depend- ing upon that with which it may be brought into connexion. However, opinion will hardly differ on tins one point : the less of an equivalent of the medium of traffic— money— is demanded for a certain article, the less It is actually worth ; and the cheapest is surely never the best, nay, often nardly snfljoiently good for the purpose it is intended. And I must say it is to the credit of the public that it is not so much the moM ofbufiTw which raises the cry of "Cheapness! cheapness!" it it more the dominating clement, the clamour of the telling individuaU. Is tb» public asking for cheap mounts— it barely asks for cheap photographs-^ and what is the ratio of cost of a mount, even if it be the best, to that of a photograph, even if it be of the cheapest ? In general, as one to ten ! In view of this, will any one dare to maintam that the price of photo- graphs is in any way affected by the cost of the cards on which they are mounted ? I stated at the beginning Tof this letter that " cheapness " is the tendency of the age, but, I must also add, " progress and improvement " not less, though these two tendencies go in different directions. Never- theless, there has been a vast progress and improvement in the quality, and especially^ in the finish, of photographic mounts. As regards the latter, it shows that a refined, artistic taste is an indispensable element in the manufacturing of such mounts, and still they have become cheaper in proportion. On the other hand, if we behold what is now also being offered by native and foreign mount-manufacturers in material and finish, it reminds us of the time when photography was still in its infancy — I mean the modern photography — -being but little superior to what at that time the photographers, as a rule, " manufactured " themselves. These manufacturers are the " Eip Van Winkles " of the photographic trade ; they have slept during the " revolution," and appear on the market with something which one should think belongs to the dead past. Is it necessary to bring forth arguments to convince that any photo- graph appears more advantageously on a good, nicely finished mount ? Just look at the show-cases of photographers, and compare the one with the other. Is it surprising when we see the mount crumble to pieces when the photograph itself has lost but little of it^ original value ? i must confess it is humiliating to the trade that this degeneration is gaining ground, and apparently gains an overwhelming influence over the photographers, and, as a necessary consequence, over the photo- graphic dealers. There is but little hope of retarding the progress o( the inundation of this "cheap" element, unless the public revolts against it, and demands, at any rate, a good, durable mount, pleasing to the eye and in harmony with modem taste. I do not plead in my own interests, but in the interests of the card- manufacturers of a higher level. We shall follow degree by degree down ward if it must be, yet continually keeping the reins upwards as long as our strength does not fail ; we have nothing to fear, and only little to lose, but I am pleading in the interest of the }>hoto;iraphk art. — I am, yours, &o., A Cabd-manufactureb. March 7, 1893. THE CBYSTAL PALACE EXHIBITION. To\the Editor. Sir, — Mr. F. P. Cembrano, jun., having been the first gentleman to consent to act as Judge at the forthcoming National Photographic Exhi- bition, we deeply regret that, owing to an oversight, his name should have been omitted from the list sent you on the 6th inst. We shall be extremely obliged if you will kindly note this in your next issue. — We are, j ours, Ac, S. G. Buchanan Wollasios, 1 Charles W. Hastings, J ' Crystal Palace, March 13, 1893. ■ Executive. BEWARE OF GLYCERINE. To the Editor. Sar, — A word or two of caution to those using glycerine for the purpose- of mixing with the oxalate solution employed in the development of platinotype. Be sure that it is quite free from citric or other acid. Quite recently I have had the mortification of seeing the image on several prints completely disappear, due solely to acidulated glycerine. I find on inquiry that a large proportion is thus sophisticated, and on sale at various druggists. It is said to be, like many other shams, " made in Germany." — I am, yours, <$.'o , Hector Maolean. 3-i, Birdhunt-road, Croydon, March 13, 1898. iExctangc ©olumn. *,* No charge U made Jor inserting Exchanges of Apparatus in this column ; but lume will be inserted unless the article wanted is definitely stated. Those whospeci/y their reijuiranents as "anything useful" will ther^ore undersUmd the reason of their non-appearance. The full name of the advertiser muU in ail cases be given for publication, otherwise the Exchanges will not be inserted. Will cichanifB fifteen monthly parts of Cassell St, Co.'» jonmal Work for finder for hand camera. — Address, J. K. Ewakt, Marine Honse, Bantf, N.B, Will exchange Adams's twelve-inoh club bnrnisher, and 15 x 12 Ross's wide-«offle laiu* for rolling: prosa.— Addreu, Stone Si, Wilkinson, 3, High-street, Derites, Wilts. Wanted half-plate landscape camera, or stndio aooMeones, in exohanffe for two iief^tiro cupboards to bold 2000 qnarter-pUte negatives, one whole-plate, and tw(V half-plate negative boxes.— Address, B. Sxauet, 139, Enston-md, Morecainbct 176 THE BRITISH JOURNAL OF PHOTOGRAPH i'. [March 17, 1&93 EnotDtrsJ to OTortesponDEnta. *,* All matters intended for the text portion of this Jourkal, Including gmries and Exchawies, must be addressed to "The Editor, The Bsitish Journal ok Photography," 2, York-street, Covent Gat-den, London. In- attention to this ensures delay. *»* Correspondents are informed that tee cannot undertake to ansioer com- munications through the post. *,* Communications relating to Advertisements and general business affairs should be addressed to Messrs. Henry Greenwood k Co. , 2, York-street, Covent Garden, London, . K. Y. T. — It is, we believe, an ordinary solution of rubber. J. C. RuTHVEN. — We should be pleased to have the communications. ■Constant Reader. — Apply to Messrs. Winstone & Sons, of Shoe-lane, E.C. Greaves.— Tlie mottling may disappear if the solution is warined slightly. Hussar.— Swell thirty grains of gelatine in water, drain,- and add one ounce of caramel. R. S. 0.— Consult the Ai.manac. The three formulre about which you inquire are given with others of a similar character. 1)E\-0NSHIRE.— Yes ; the photograph can still be registered ; but it is doubtful if it will be of any use as regards those copies already issued. A. R. T.— You will see a reference is made to the subject in another column. Of course, the copies must be good, or they would not meet with success ; also the subjects must be of a popular character. T. Steele. — The one is a more modern lens than the other, lint will answer your purpose no bettor. The triplet is an excellent lens for copying, and is largely u.sed by commercial copyists, some of whom prefer it to lenses of the "rapid " type. B. W. C— 1. The stand attachment is identical with that patented by Messrs. Mason & Henderson. 2. It is not necessary to coat gelatine negatives with coUoilion prior to varniehing them ; but it is better to do so, as it affords greater protection. Pyro. — Try the effect of a strong solution of cyanide of potassiiuii and pumice stone if the other things fail. If the nails are badly stained, they are very difficult to clean. Stains, by the way, are easily avoided, but not so easily removed when once they are formed. T. Crowe asks how he can know when he has washed all the nitrate of silver out of the prints before they are toned ? — If the last washing water is clear and does not become turbid on the addition of a pinch of salt, it may be assumed that all the free silver is removed. "VV. McC. — You will see by Mr. Wellington's jiaper on the subject that the Company do not apprehend any injury to Solio jiaper by the use of the combined toning and fixing bath. If you carefully follow tiie instructions in making the bath, no fumes should lie given off. L. S. D. — There is no regular rule with regard to resittings in first-class esta- Ijlishments in London. The custom is to satisfy the sitter whenever it is po.ssibie. We quite sympathise with you, and other portraitists, in the matter of the unreasonableness of some persons. For that there is no panacea. R. Tremkre. — For portraiture an arc light of from five to six thousand candle jiower is desirable; but, for copying from small-size originals, one of two or three thousand candle power will suffice. Of course, such a light could be used for portraiture, but the exposure would be proportionately longer than with the more powerful one. C. Weltox. — If you can obtain a current from the mains, it would certainly be more advantageous to take it from that source than to go to the expense of the necessary plant for generating it yourself. The cunent from the mains being of so high a voltage is of no moment That may easily be reduced to anything tliat may be required. E. Hajiilton. — The trouble arises from the tissue not being in the right con- clitiou when it was squeegeed on to the plate, or maybe from tlie squeegee- ing not being properly done. If the tissue be too moist, or not moist enough, this diltlculty may be expected. Master the details of carbon printing, and the trouble will not l)e experienced. A. W. Ai.LABD.— 1. Instead of diffusing the light, it wants more concentration on the sitter. There seems to be too nmch top light for that form of bidld- ing. Stop off all direct front light, and two feet or more of the extreme top light. \Vliat light then remains will lie ample and easy to control. Any quiet, unobtrusive colour, such as a greyish blue or green, will do for the side wall. S. A. T. asks the best way of reproducing negatives. There is no best way, because all the recognised methods are equally good in tlie hands of skilled workers. The simplest method is, make a transparency by contact priuting on a dry plate, and from that produce the negative' Tiy the same means. Excellent negatives are made daily by making a carbon transparency, and from that the negative by the wet-collodion process in the camera. W. A. T. writes : " Will you kindly say— 1. What fuming with ammonia does to sensitised albumen paper ? Does it make it l;eep better, or what ? 2. Also .are the following brands of albnmen paper the best to be obtained?"—!. Fuming with ammonia does not ?ild to the keeping qualities of the paper! It is said by tho.se who employ the method to improve the qiuality of the prints. 2. It is quite against oni rule to recommend any particular make of juaterial. All the brands named however, are good. Widow. — By no means pay such a sum as a premium for your sou to be " articled " for three years to leani the portrait photography as a source of livelihooil. The whole business is at present in a very depressed state, and : there is, we fear, little prosjiect of any immediate improvement. Further- more, the labour market is, and will be for some time to come, overstocked. If he must follow photography, the photo-mechanical branches just now are the most promising ; but these are fast being ovenlone. Have nothing to do witli the so-called erystoleum and similar styles of colouring. T. M. says : " I have a quantity of old silver plate, which I have, as executor, to dispose of to the best advantage. There are over seventy oimces of it, and it occurs to me that if I were to dissolve it in nitric acid, and crystallise it, I could sell it to photographers, and so realise more than by selling tlie metal to a refiner. Will you please give me your idea on tha subject ?" — By all means sell the metal as it is. Supposing the metal were pure, it would not pay for the time and material refpiired to convert it into nitrate ; but, as silver plate is alloyed with coiiper, the nitrate of copper that would be formed must be separated before tlie nitrate of silver would be market- able. Received.— />r?/ Plates, Shapoor N. Bhedwar, C. G. Ablett (Port Elizabeth), and others. Photographic Club. — March 22, New Cameras: adjourned discussion on The Combined Toning and Fixing Bath; The Sandcll Plate, by Mr. S.Herbert Fry. 29, Lantern Night. London and Provincial Photographic Association.- March 23, Technical Lecture, by Mr. Edgar Clilton, Cameras, Tripods, and Dark Slides. 30, The Sandc/l J'late, demon.stration by Mr. S. H. Fry ; Strippiiig Gelatine Plates for Colb'tgpe Work, by Mr. W. J. Rawlings. April 6, Uelerminatian of Plate Speeds, by Mr. G. F. Williams. On March 23 the Woolwich Photographic Society will hold a Lantern and Musical Entertainment. Richmond Camera Club. — March 20, Demonstration on Printing, Toning, and Dereloping Oelatino-chtoride Paper, by Mr. Gotz. Bolton Photographic Society's Exhibition. — We .are informed that the Society will pay carriage on all exhibits in the Champion Class. We have been shown several examples of Messrs. Morgan & Kidd's machine- collotype process, which attest the remarkable readiness with which this firm has thus early achieved excellence of results with the process. Hackney Society's Futurp: Arrangements. — March 21, Demonstration of Saiidell Plate, Mr. S. H. Fry. 28, London. Street Cries, Mr. E. Scamell. April 4, /-"/iOtoyrm'Mrc, Mr. A. Dawson. 11, Members' Lantern Night 18, Record and Sm-vey, Mr. W. .Jerome Harrison. 25, After-work of Hand Cameras, Mr. A. R. Dresser. May 2, Annual Meeting. On S.aturday afternoon a new photographic studio, to he known as the Delmen Art Studios, Limited, was opeueil at 470. Holioway-road, N. Messrs. Downey and Mr. Mendelssohn, on behalf of the Directors, received the visitors. Although scarcely yet finished, the suites of rooms are elegant and nicely planned for a photographic business. All the rooms are fitted with the electric light Mb. J. Small, of Dartmouth, writes : "This last week or two mention has been made of mammoth enlargements. I was not awij-e they were novel, as the celebrated firm of Marion & Co. made me, from a carle negative, an en- largement, seven feet six inches by four feet six inches, of Lord Northbrook's son, who was drowned in H.M.S. Captain. This was in December, 1870. The enlargement was painted by tlie Hiitn. Graves, of Bond-street, at a cost of 600 guineas. The Autotype Company have made me several enlargements 48 X 36, so that I rather read the announcement with a little surprise. " We have received from Messrs. Perken, Son, & Rayment their wholesale and export illustrated Catalogue of lanterns, slides, gas bags, jets, and everything else connected with the lantern, together with an illustrated Catalogue of cameras and the numerous and varied appliances of jihotography. Their new lecture sets for the lantern are so comprehensive as to afford Idghly suggestive matter for those wjio contemplate making camera trips during the approacliiug season. As regards the numerical strength of this department alone, it is such as almost to defy counting. The quality of such of these as we have seen is of the very highest order of excellence. Photographers' Benevolent Association. — A Committee meeting was I1.-M at the registered oflices of the Association, Memorial Hall, E.C., on Maroli 13, Mr. Alexander Mackie in the chair. Three applicants for assistance appeared to state their cases, and in each instance the assistance asked for was granted. It was in small sums — one pound to set up a roadside worker with appjiratus. a few shilings to help an out-of-work man to reach his next situation, and a few shillings to redeem a man and his wife from .actual starvation. A cou|de of pounds covered the whole of the grants, bnt the investigation of the cases occupied over two hours. Thirteen new subscribers, who had been introduced by Mr. Birt Acres, were accejited, and a hope was expressed that otlier managers and employers would introiluce the subject of the Benevolent to their employes as Mr. Birt Acres had done. OONTENTB. Pa(MI mixed developers liU LENS FOa 162 SOLUTION - MAKING. By O. WAT- MOUGH WKBSTEK !« JOTTPNGS. Bv cosmos 104 CtKOIIGE WASHINGT. N WILSON 105 OS THE PRODUCTION OF BLACK AND WHITE negatives IIY MEANS OF AHTIFICIAL LIGHT. Bv T. N. ARMSTRONG 166 "SPIRIT PHOTOGRAPHY," WITH RE- MARKS ON FLUORESCENCE. By ■1. TRAILL TAYLOR 107 ON DIVKRS 8UB.IE0TS. By W. J. SIILLMAN 169 Page NOTES FROM THE CAPE. By C. RAY WOODS 170 LIGHT, SHADE. AND PICTURE COM- POBITBON 171 MANCHESTER PHOTOGRAPHIC SO- CIETY'S EXHIBITION 171 THE CENTRAL PHOTOGRAPHIC CLUB 171 OUR EDITORIAL TABLE HI MEETINGS OF SOCIETIES 172 KOllTHCOMING EXHIBITIONS 174 RECENT PATENTS 17» CORRESPONDENCE 171 EXCHANGE COLUMN 176 ANSWERS TO COIUIESPONDENIS 176 THE BEITISH JOURNAL OF PHOTOGRAPHY. No. 1716. Vol. XL.— MARCH 24, 1893. ELEVATING THE POINT OF VIEW. The view of a place which will be most fiimiliar to the observer is that which is obtained from a height approximating to that of the human eye, or, say, a little over five feet from the ground. Numerous camera stands fall far short of fulfilling this reijuirement — a fact readily perceived when one watches a party of cameni men in the field, and notes how they stoop when focussing or arranging their subjects on the ground glass of the camera. To obtain a view as seen by the eye, the camera stand ought to be elevated to such a degree as to permit of the focussing screen being brought directly opposite the eye. This is a truism which requires no elucidation. While " 'tis well to have a giant's power," there are numerous occasions on which it would be exceedingly unwise to take advantage of it. A lakelet, a stream, or a flat meadow in the uear foregroimd might, from the usual point of view, assume a magnitude of expanse so pronounced as to detract from — nay, eclipse — that of the scene beyond, unless thrown into subor- dination by lowering the point of sight to within one or two feet of the ground, so as to foreshorten these obtruding and undesirable commonplaces. The photogi-apher, who is also an artist, understands full well the value of selecting a point of sight tliat will ensure him getting all the pictorial effect necessiiry, and it is fortunate that the mechanical construction of most of the camera stands enables this to be done without difficulty. But there is another view of this question of height, and that is, when it is found expedient that the point of sight be higher — in oftentimes a considerable degree — than that capable of being attained by our ordinary appliances, What is to be done when a tall fence, or other equally tall obstruction inter\-enes between the only 1(kiis siawli for the camera and the subject that is to be taken ? It is now about twenty years since we saw among the outdoor impedimenta of a photographer in the provinces (Mr. Bottomley, Leeds) a camera stand constructed expressly for meeting s\ich contingencies as those just hinted at. Each limb of the tripod was fourteen feet in length, and formed a ladder, up which the adventurous photographer had to climb with his camera until he reached the top, which formed a small platform, from the centre of which rose a stout piece of wood, supporting the table on which the camera was planted. Think of the advantage possessed by a man perched on such an elevation over another nine or ten feet nearer the ground I Foreground obstructions h;ivo for him no existence. There are other subj'ects for which a tall stand is an abso- lute necessity. A photograph in our possession, received from Dr. Le Plongeon, shows that intrepid traveller and explorer engaged in the act of photographing the details of carvings on the wall of one of the temples in Yucatan, Central America, this being done from the gi-eat elevation necessary to bring the camera opposite to the architectural tracery which is being depicted. On this occasion he employed a stand, the legs of which were twenty feet long. It was composed of a ladder and two other supports, formed of bamboo. While such tall stands are only required for special pur- poses, and are not necessary to the amateur, portability being quite out of the question, yet would we put in a strong plea for portable stands, by which the camera could, when required, be elevated to, say, seven feet when required. We have tried the effect of extemporising an additional joint to each leg of one by which this height is attained, and find that it places a great power in one's hands. With the camera at the usual elevation, much prominence was given to trivial foreground objects ; with the greater elevation these disappeared, their places on the plate being occupied by others at a greater dis- tance. Incidentally, we experienced a slight diflBculty in arranging and focussing the subject on the ground glass, and in inserting the slide and withdrawing the shutter. But by the adoption of a portable stool, about eight inches by twelve inches, the legs of which fold underneath, this difficulty is entirely overcome. A stand of this nature is so useful, and may be constructed at a cost so little in excess of one of the length now usually made, that we strongly recommend its adoption. Apropos, many users of hand cameras err in holding their cameras so low as they do. We can readily understand that an excuse for this is to be found in the fact of the assumed necessity for having to allow a certain space to intervene be- tween the eye and the finder, upon which the user looks down ; but, as we have shown on former occasions, direct finders may now be obtained, which may be placed so as to be used opposite the level of the eye, by the use of which the point of sight is considerably elevated. Since 'writing the foregoing we have learned that a tall stand, such as we desiderate, has been exhibited by Messrs. Houghton &. Son at the Photographic Club, and, from sub- sequent examination, find it fulfils every reasonable require- ment. We hope that the manufacture of such stands will become universal. THE WELSBACH LIGHT FOR STUDIO WORK. Exactly two years ago (p. 193, vol. xxxviii.), we described an arrangement which we were shown by Mr. Atkinson, of Liver- pool, for the utilisation of common house gas as the illuminant in studio portraiture. Briefly, it consisted of placing the sitter 178 THE BRITISH JOURNAL OF FHOTOGRAJ'H Y. [March 24, 1893 inside of a portable room, and directing the camera towards him through an aperture. The light was obtained from a row of gas jets, with reflectors, placed above the sitter, where the top light might be supposed to be, and another row behind a dif- fusing screen, as the side light. By the system and power of light used, an exposure (with a portrait lens, of course), of ten seconds, was practicable. We suggested at the time that, by increasing the illuminat- ing quality of the gas, the duration of the exposure might be diminished, while we regarded, and still regard the idea of utilising house gas for portrait purposes as capable of being turned to great practical account in the hands of photographers. A similar idea is evidently entertained by the Incandescent Light Company, of Palmer-street, Westminster, who are adapt- ing their well-known Welsbach light for portrait work in the studio. An opportunity for observing the capabilities of the light was recently afforded us in the studio of Mr. Charles F. Treble, of Clapham Junction, who has had it in use for the last three months. The arrangement adopted by the Incandescent Company may be described as follows : — As the top light, and placed behind a translucent screen, is a row of jets with the now- familiar incandescent mantles, burning gas from the main, pro- tected by glass chimneys and having metallic reflectors. On the side from which the side light comes, two other rows of lights are placed behind the same kind of screen, one system of gas piping being employed throughout. On the shadow side, and as a background, a large rectangular portable screen of a tint reflecting as much light as possible, is placed, con- ditions which, we were informed, are also necessarily applicable to the floor and the ceiling. In all, some seventeen lights are used, the estimated candle power of each being about 120. This large volume of light allows of the exposure, under favourable circumstances of lens aperture and sitter, being so short as six seconds. A con- siderable but not uncomfortable degree of heat is given ofif, and the lights, although powerful, do not emit any inconvenient glare, or dazzle the eyes as other illuminants do. The flames, besides, are perfectly steady and noiseless. From personal observation of a sitter, we had opportunities of noticing that the light cast on the face is of a soft, agreeable nature, and such as, by its inherent properties, ensures the negative falling short of hardness. ^Moreover, we ourselves sat while several trial negatives were taken, so that we can attest its lack of discomfort so far as the sitter's eyes are concerned. The charmingly lighted work which Mr. Treble himself has pro" duced by the illuminant, points to its high capabilities in the hands of the photographer. We gathered that the consumption of gas involved is, all things considered, not so formidable as might have been supposed from the number of burners. The employment of house gas for studio portrait work, in accordance with the above-described system, should be welcome to photographers, not only in winter time but at other seasons of the year, and at evening, when natural light is unobtainable of sufficient actinic force, or magnesium and electricity are either unsuitable or too expensive. COMBINATION PRINTING. It may seem a little strange at the present time to have to say anything about such a simple matter as double printing ; but, if we may judge from the letters we are constantly receiving, not only from amateurs, but from professionals even of some few years' standing, asking how one or more figures in a group that may be unsatisfactory in one negative, from a movement or expression, may be replaced by more satisfactory ones from another, iufoi-mation on the point may be of general value. To do such a thing in several different ways would give no trouble whatever to a printer of the old school, and that, too, without showing the slightest indication of a join. At one period in the history of photo- graphy, as some of our older readers will remember, almost the first question put to a printer seeking employment was. Can you mask well 1 For at one time it was rarely that a portrait was printed with the background that was in the negative, a& a new one, nicely shaded, was generally substituted. Nowa- days, there are few printers who are skilful at double priuting Combination printing may be classed under two heads vignetting and masking. By the former method the jtmcture is made by vignetting the edges of one picture into similarly shaded ones of the other. "This was the system followed by Rejlander in producing his once well-known picture, Tke Two Ways of Life, which was printed from upwards of thirty different negatives, and so skilfully was the work done that the junctions of the various printings could not be detected. The same principle was also adopted by M. Lambert in the " Lam- bertype " process. This method requires considerable skill on the part of the operator for its successful working, and it is better adapted for large sizes than for small ones. The more generally practised method of double printing is by masking, and it is the one the novice will succeed best with. Let us take, by way of explaining it, two negatives of a group of several persons — usually, in taking a group, a couple of exposures are made — and one or two figures in one are unsatisfactory, while in the other they are perfect ; but it is the first picture, as a whole, that is preferred. Now it is required to substitute the approved figures for the faulty ones. Portrait negatives have been taken by way of illustration, simply because recent queries have applied more particularly to them ; but it will be obvious that the same systems are applicable to all classes of subjects. Take, say, first the nega- tive with the figures to be substituted, and stop out neatly all portions, with black varnish, except these figures, so that they will print with a perfectly white groimd. In the other negative these figures only are stopped out by the same means, leaving the other portions of the negative intact. After the first nega- tive has been printed, it is quite eas}- to place the print in its exact position on the second negative for the second printing, so that no junction will show when finished. Instead of painting out with black varnish, the old method was to make a light print from one negative — sometimes from both — and then cut out neatly with a penknife the difierent portions, and then, after the paper had been blackened by exposure to light, cementing them as masks in proper position on the difierent negatives. The cement generally used was indiarubber solution, as that did not cause an expansion of the paper as an aqueous cement would do. This plan has also the advantage that the paper can be taken ofi", and the nega- tives restored to their original condition. This is not always possible with black varnish containing bitumen when it has become insoluble by exposure to light. It is a very important point in double printing, especially in the case of portraits, to have the paper in the same hygroscopic condition for the t*» printings. Paper, it is well known, expands with moisture, and it is manifest that, if one printing is made with it very dry and March 34.18931 THE BRITISH JOURNAL OF PHOTOGRAPHY. 179 the other after it has been allowed to absorb a certain amount of moisture, accurate registration will not bo obtained. Further, if the pa])er is not in the same condition as regards moisture in the two printings, a uniform tone will not be obtained in the finished result. Here is another system of double printing which is exceed ingly satisfactory, and requires oven less skill in its working than that just referred to, as, with it, the masking of only one negative is necessary. It is therefore bettor suited to the re- quirements of the novice. It is based upon the plan introduced many years ago by Mr. Edge. The first negative has all stopped out — either with black varnish or a paper mask — except the figures to be introduced into the other. It is then printed. Then these figures are neatly painted over with a non-actinic water colour — such as gamboge — and allowed to dry. The colour protects the printed imago from any further action of light. The print is then placed in position on the second negative, which is readily done, and printed. After the second printing, the toning and fixing is, of course, done in the ordinary way. The gamboge readily dissolves off in wash- ing the free silver out of the paper. With this method, as we have just said, only one negative need be masked. It has also this further advantage, that, as the first printed image is per- fectly protected from light by the pigment in the second print- ing, therefore it will not be affected by any little inaccuracy in the registration. As described, this method would only do for albumen paper, as it would be undesirable to apply water colour on gelatine paper, because it might soften the coating and be absorbed by it. However, gamboge is soluble in spirit, and gelatine is un- affected by that ; therefore the gamboge should be mixed with alcohol instead of wdter. • Then, after printing, the colour can easily be removed by a sponge charged with spirit prior to washing out the silver for toning. Photographs of Jupiter. — The Itoyal Astronomical Society at its tirst meetinp; of the new Session, in enuraeratinjf the present received, referred to some exceedingly beautiful photographs of Jupiter from the Lick Observatorv. Solidified Air. — The latest and most remarkable outcome of the experiments upon the compression of gases, recently popularised by I'rofessor Dewar, is the solidification of air, a product described by the learned professor in a communication to the Royal Society a fort- niifht ago. The ex.ict condition of this solid matter is yet a matter of doubt. It may be solid air in which both constituent gases are frozen and pressed into solid nir ; or, it may be, a kind of jelly of nitrogen with liquid oxygen entangled like solid gelatine holding water. Hitherto, though nitrogen has been frozen, oxygen has resisted all attempts to pass it beyond the liquid stage. Secog-nlslng- metol by Its Smell Writing of metol in the current number of the Journal of the Photographic Society of /Wot, Colonel Waterhouse says : "I have not worked further with metol since my last paper on it. I have, however, noticed one fact regarding it which may be worth recording, and tliat is, that old metol solutions can easily be recognised by the strong smell of phosphorus they evolve. I observed this smell in testing it with various reagents. Wetol is said to be the sulphate of mono-methyl para-amido-meta- kresol, but is possibly a phosphate or phosphite of this compound. The smell of phosphorus is most decided and unmistakable." • ■ Simple Specific-gravity Apparatus.— An exceedingly idmple and, evidently, roughly correct contrivance for quickly taking specific gravities is described in n recent number of the Wiener lierichte. It consists of two glass tubes joined by an indiarubber tube. One of the former is thirty centimetres long, and about one wide. There are scratched upon it two marks twenty centimetres apart. This tube is immersed up to the lower mark into the liquid to be examined, and at the same time the other tube is immersed in water. Upon withdrawing the tubes the water rises in one, and the other liquid in the other tube. When this latter reaches the upper mark, the height of the water column is noted on a suitable scale, and it* height measures the density of the liquid under examination. Orthoohromatislngr Gelatine Plates.— Colonel Water- house says : "For some time pasti have been orthochromatising my gela- tine plates by bathing them for one or two minutes with the tincture containing erythrosin silver and ammonium picrate used for the ortho- chromatic coUodio-bromide emulsion process described in the February number of the Journal of the Photographic Society of India for last year. The formula is as follows : — Erythrosin, 1 part ; silver nitrate, 1 part ; picric acid, 1 part ; ammonia (s.g. "880) about 30 parts ; spirit of wine, 500 parts ; water, [500 parts ; one part of the above solution being diluted with nine parts of water to make a solution containing about one part of dye in 10,000 of fluid. More ammonia may be added, in the proportion of one part to 100 parts of diluted solution. This works exceedingly well for most purposes when ortho- chromatic plates are required, and for landscape work with the tele- photo lens no yellow screen seems to be necessary, unless there is much blue haze in the distance. The quantity of ammonium picrate may also be increased in such cases." Photog'raphy versus the Eye in Photogrraphs of Clusters. — Dr. Isaac Roberts recently read a paper on this subject, and brought out in a remarkable manner the contrast that was to be found in these two classes of records. Thus, while Sir John Herschel described a particular cluster as " bright, round, rich, and composed of pretty large stars down to the eleventh magnitude," the photo- graphs of Dr. Roberts, taken with an hour's exposure, show the cluster to be composed of stars of very different magnitudes, ranging from the eighth to the fifteenth, and not round or symmetrical in shape. An interesting question arises from another photograph of Dr. Roberts's, whether some stars in another system, not hitherto catalogued, but found on the photograph, are a system in motion ? A further photograph, taken some years hence, may show whether the possible motion takes place or not. During the discussion on Dr. Roberts's paper, a question was put as to whether it was possible that the nebulous appearance seen in the plates was due to photographic action rather than stellar images ? But Mr. Ranyard stated that this was almost impossible, seeing that negatives taken by Dr. Gill at the Cape exhibited, down to the minutest details, the same appearances as Dr. Roberts's. It might be expected, if the appearance was not really a representation of a telescopic image, it would differ according to the instruments and processes employed. 'Weinek's Snlarg'ed Xiunar Photog'raph.— This photo- graph continues to excite considerable discussion, and many experts declare its details in parts to be due to something other than simple enlargement. Many details of surface structure are visible which hitherto have escaped detection in eye observations — winding rilli, valleys, and hairlike markings. These were quite sharp and distinct, and in contrast with the larger-surface pictures — a condition which has led to their being challenged. In contrast to the usual experience with enlargements, sharpness being then diminished, we have in this lunar photograph minute details after an enlargement of twenty diameters, while other larger portions are " fuzzy." In the Observatory of this month Mr. Hger says : " If these curious markings represent actual features on the moon's surface, ought they not to be easily seen in any good telescope that shows the formation and its principal details with far greater sharpness than the twenty-times enlarged negative, and many small craters, &c., in addition, which are scarcely trace.ible upon it ? One dojs not understand why this should not be 180 THE BRITISH JOURNAL OF PHOTOGRAPHY. [March 24, 1893 80, unless these objects make an impression on the sensitive plate that they fail to do on the retina, which is hardly likely to be the case." Many experts, it appears, are reserving their judgment. To us the simplest method of solving the matter would be to have the original negative enlarged by a second photographer, a preliminary examina- tion of the original for technical defects, and a comparison of a second enlargement eyen on a smaller scale would at once show whether Weinek's picture was a true photograph or not. TExMPERATURE IN THE DARK ROOM. Although it is but a few weeks since attention was called to the importance of maintaining a uniform temperature in the dark room during the winter months, it is more than probable that the sudden change of last week has brought trouble into very many photographic establishments. A spell of iine weather, more resembling summer, in the matter both of light and temperature, tlian late winter, or even early spring, has been suddenly succeeded by a sharp " snap " that would have done credit to mid-winter, and photographers — good, easy men, who have fondly imagined the cold season had departed, and have become careless in consequence, have no doubt suffered correspondingly. The danger to which we wish more especially to direct attention in the present article is not connected with the mere warming of the studio and dark room, though that, of course, if neglected, will con- tribute materially to the seriousness of the visitation, should such occur ; we have at present to deal with a more insidious foe, more dangerous, perhaps, from the fact of its, in many cases, being unsus- pected— namely, the fall in temperature of the water supply. That the water is colder after a sudden fall of temperature, such as that of the past few days, becomes painfully apparent to those who have to dabble in it, in either developing or printing operations ; but, so long as the studio and developing or printing rooms are kept properly warmed, the tendency is to suppose that everything has been done that is necessary. Such, however, is not the case, as we have re- peatedly tried to show in years gone by, and, as the danger lurks during the summer months, though perhaps to a less extent, as well as in the winter, we make no excuse for pointing out in what wav inattention to this important point may cause serious trouble. We need scarcely repeat the truism that chemical action of every kind goes on more rapidly, as well as more energetically, at a high temperature than a low one. We employ hot water instead of cold in such simple operations as solution-making, in order to hasten the process, and every one knows that a warm developing solution acts not only more rapidly, but also far more vigorously, than a compara- tively cold one. And yet, in spite of these obvious facts, many photographers are content to use their developing, fixing, sensitising, and other solutions, as well as the water they employ in washing, at nearly freezing point, and expect them to behave in the same manner as when they are thirty, forty, or perhaps fifty degrees warmer. The chemist is careful in performing any experiment or operation in which uniformity of results is necessary for comparative or other purposes at a uniform or standard temperature, knowing well that it is only under such conditions that a proper and accurate comparison can be made ; and it is equally important that a similar course should be followed, by photographers, though it is scarcely needful to observe the same rigid uniformity as the chemist. The general principle should be borne in mind, though the latitude permissible in photo- graphic operations permits of considerable variation without materially affecting the results. Let us point out one or two instances in which carelessness in this respect may work injury. It has been remarked that the temperature of the developing solu- tion seriously affects its energy ; this applies not only in a chemical, but also in a mechanical way : or, in other words, not only does an abnormally cold solution act less powerfully as a developer, but it also penetrates into the film of gelatine with far less rapidity, so that we have a double retarding action. This was brought forcibly to our own notice a few days hack, when, on attempting to develop one of a series of exposures, several of which had already been developed successfully, we could obtain no trace of an image after several minutes, althoiigh the conditions were apparently identical. The ^dea arose that it was a case of having forgotten to draw the shutter, until we remembered that the plates previously developed had been treated before the sudden fall of temperature. On procuring a supply of hot water with which to raise the tem- perature of the developing solution itself to a normal of 58° or 60°, and reapplying, the image at once commenced to appear, and pro- gressed regularly and precisely as the previous ones had done. A still more remarkable result accrued, and one which shows more forcibly where danger may arise when an assistant neglected to raise the water used to the proper temperature — an omission we failed to discover for some time. Two plates had been exposed, one after the other, on the same subject, the light having practically not changed in the slightest, the second exposure, however, being about four times as long as the other, which had been cut short owing to the movement of a portion of the subject. The shorter exposure was developed first, and proved, with suitable development, a fairly satisfactory negative. It was on the finish of this that a fresh can of water was brought in, the temperature of which was some ten or twelve degrees lower than what we had been using. Unconscious of this, we proceeded to develop the duplicate exposure, treating it in accordance with its increase of time and the result obtained from the other. The progress of development was much slower, and the contrast obtained much greater, owing to the shadow details hanging back while the lights were gaining density. On discovering the mistake, it was too late to remedy the matter, for, though unnecessary detail was obtained in the shadows, the high lights under the modified treatment became too dense, and the second image appeared to have had much the shorter exposure. This, of course, is a result that could only ensue from care- lessness, but it shows in a marked manner the absolute need for uniformity of temperature from day to day if equality of result is desired. It also shows, what it was attempted to demonstrate in a leading article in these pages some years back, that the temperature of the developer alone may have an effect on the cliaracter of the image that no variation of the proportions of the ingredients will alter. It is not necessary to recapitulate all that was said in that article, but it may be stated in brief that the results of experiments showed that cold developing solutions conduced to brilliancy and clearness, while a higher temperature produced greater softness. This general result could not be altered by vari.itions of the ingredients within the bounds permissible for successful development. It appears, in fact, as if the cold developer is incapable, with a given, or even with an increased, exposure to search out details that are readily brought out by a solution a few degrees warmer. GLYCIN. [Journal of the Photographic Society of India.] Glycin appears to be identical with p. oxy-phenyl-glycocoll, or para- oxy-phenyl-amido-acetic acid, with the formula — J OH ^«^^4nh, CH„, COOH. and is prepared, according to Vater, by the action of chloro-acetic acid upon para-amidophenol. It is therefore a chloro-acetate of para-amidophenol. The sample I have is a light cream-coloured granular powder, not altering readily in the air. It is not very soluble in water or in alcohol, but dissolves easily by the addition of caustic alkalies or their carbonates. The watery solution has a strongly acid reaction, but it is quite colourless. Alkaline solutions take a yellow tint, which dis- appears on the addition of sodium sulphite. It is easily soluble in dilute nitric, sulphuric, and hydrocliloric acids, the solutions being quite clear and colourless. It is not so readily soluble in weak bromine water, but the solution becomes colourless. Nitrate of silver first turns the glycin solution a turbid, dirty greenish- black, but it afterwards takes a violet tint, like slightly darkened chloride, and silver is precipitated, but not in the bright metallic form distinctive of metol. The same change takes place if the glvcin solution be acidified with nitric acid before the addition of tlie silver salt; the silver precipitates, and leaves a clear solution of a beautiful purple colour. With a solution of glycm made alkaline with potash, nitrate of silver gave at once a thick brownish precipitate. The manufacturer recommends two solutions for developing, ac- March 24, 1893] THE BRITISH JOURNAL OF PHOTOGRAPHY. 181 cording as the negatives are required to be soft and detailed, or hard and dense, and glycin is said to be especially suitable for reproduc- tions of all kinds, photomicrography, &c. llie formula for the first developer is : — A. Glycin 4 parts. Potash 15 „ Sodiuni sulphite (crystals) 12 „ Water 100 „ B. Potash 10 „ Water 100 „ For use, one part of A is mixed ^vith two parts B. Heat is required to dissolve solution A; but I find that, on stand- ing, the salts have crystallised out in very pretty, thin, long hexagonal plates. The second developer, for dense negatives, is as follows : — 2. Glycin 5 parts. Potash 26 „ Sodium sulphite (crystals) 25 „ Water 100 „ diluted for use with three parts of water. In preparing this, it is well to first dissolve the potash in the water, then the glycin, and add the sulphite. The solution is nearly colour- less, or a dirty white, and does not readily change by keeping, either in colour or in its developing power. I have not yet ascertained its full keeping powers. Both of these forraulse give powerful and effective developers, yielding images of great density and brilliance, with clear shadows and perfect freedom from stain. Like other para-amidophenol de- velopers, they require good exposure, and the density depends a good deal upon the length of time the plate is left in the solution, as is also the case with ferrous oxalate and and the sulpho-pyrogallol de- velopers. The action of glycin is slow compared with amidol and metol, but not inconveniently so, and there is not the same tendency to a general veiling over tlie image. I find both developers quite suitable for ordinary landscape work, the first formula being, perhaps, the better, while, for copying, the second is more suitable. They also work very well with orthochro- matic plates. I have not yet tried them for instantaneous work, but with a suitable very rapid plate, and a large aperture of a quick- acting lens, they would probably answer. Several plates can be developed in a batch of developer without any marked change in it. The stability of the glycin, both dry and in solution, the density and clearness with which it works, and the latitude that appears to be permissible in exposure, seem likely to give it a very great advantage over para-amidophenol hydrochlorate and other new developers lately introduced. Largely diluted, it would probably be an excellent developer for lantern slides or for bromide paper. A voltametric examination of the developer, made up according to formula 2, shows that it evolves hydrogen more vigorously than any other developer I have yet tried, and this would appear to favour the hypothesis that developing power is dependent, other conditions being suitable, on capacity for evolving hydrogen. The dilute solution, made up in the above proportions, contained: — Glycin 1-25 parts. Potash (anhydrous carbonate) 6-25 „ Sodium sulphite (crystals) 6-25 „ Water 10000 „ This solution was first electrolysed in the tube voltameter, described in a previous paper, with platinum electrodes, using, as before, a battery of four gravity cells, the current being 280 miUiamperes, with a pressure of 4'2 volts, the resistance of the galvanometer being one ohm. The current through the voltameter at starting was eighty milliamperes, with a pressure of 3'2 volts, and in twenty minutes it had decreased to about seventy-five milliamperes, and 3'15 volts. At starting, the solution in the tubes and the outer vessel was quite clear and colourless, the temperature about 72'o'' Fahr. When the cur- rent was turned on, tiie evolution of hydrogen was very brisk, and the yield was, in five minutes, 2-5 c.c. ; in ten minutes, 6-4 c.c. ; and, in fijfteen minutes, 7'C c.c. This corresponds very closely with the results obtained from an ordinary ferrous-oxalate developer containing four drops of a ten per cent, solution of potassium bromide to 120 c.c, or about one drop to the ounce. In this case 5 c.c. of hydrogen were evolved in ten minutes, the current, with the same four-cell battery and voltameter, being about seventy-five miUiamperes, with a pressure of Sl'o volts. The solution in the oxygen tube turned a bright yellow, and the anode was surrounded by a dense layer of yellow solution. The general body of the solution in the outer vessel did not change colour, nor did that in the hydrogen tube. At the end, when the oxygen tube was removed and the solution in it mixed with the remainder, the whole was a bright yellow with a slight blue fluorescence. With silver electrodes, the evolution of hydrogen wa» not so briak, possibly owing to the immediate formation of a falm of oxide on the anode. With the same battery the current through the voltameter at start- ing was about eighty milliamperes with a pressure of 2'7 volts, and in twenty minutes it decreased to seventy-five milliarapires with 2'5 volts. The yield of hydrogen was, in five minutes, 22 c.c. ; in ten minutes, 4'6 c.c. ; and in twenty minutes, 9'3 c.c. The anode was covered with a flaky deposit of silver oxide (P), and ribbon-like streams of a turbid yellowish solution were given off above and below the anode plate. As in the case of the platinum electrodes, the colour of the solution in the outer vessel was not much changed ; and, when the solutions were mixed at the end, the mixture was slightly turbid and not such a bright yellow, but it was also fluorescent. Dr. Eder, who reports on glycin in the Photographische Corre- spondem for October, 1892, speaks highly of it, and gives a formula for a glycin-soda developer as follows : — Glycin 3 parta. Sodium sulphite l.'i „ Crystallised soda 22 „ Water 200 „ The solution can be used at once, and keeps unchanged for a long time in closed bottles. It gives clear and soft negatives, and, by, lessening the quantity of soda or diluting the solution, the negatives will be more transparent. By adding oromide of potassium, even decided over-exposure can be remedied. Baron von Hiibl has found glycin a very valuable developer for collodion-emulsion plates when made up according to formula 1, diminishing the water to 80 if greater intensity is required, or mixing one part of solution A with three to five parts of B, or diluting the normal developer if less density is required. He says that this de- veloper gives, with collodion-emulsion plates, perfectly clear shadows, a good and very compact deposit, rich half-tones, and a surprisingly beautiful gradation. This agrees with my own experience of para- amidophenol hydrochlorate as a developer for collodio-bromide emul- sion plates. CoLONEi. J. Watbbhouse, I.S.C., Assistant Surveyor- General of India. AMERICAN NOTES AND NEWS. The Medal Question in California.— Our sprightly young contemporary. The Pacific Coast Photographer, says : " We wonder why the English photographic journals are so constantly quarrelling over the disposition of medals — whether an already medalled picture should be allowed to compete again in the form of a lantern slide, or else in some other exhibition, or whether a con- tributor with a string of medals as long as his arm has or has not the right to enter his pictures and hunt for more 'honours;' and, wondering, we are rather led to think that this is about all for which English clubs are organized — holding exhibitions and distributing medals. However, a liberal ray of truant light seems to have started our foreign friends in a — to them — new direction, for there is now a movement to establish a central photographic club with meeting rooms, dark rooms, and work rooms. Out here, on the frontier, we have had 'such an organization for a number of years. It is called the California Camera Club. They have had only one public print exhibition, and that was simply a quiet little time, and there were no medals. The photographic press ought to use its space to better advantage than squibbling about the awards of medals. As a pointer, however, the way the matter would be settled over here — when a man showed the disposition of greed to such an extent that, after receiving tliree or four medals, he still wanted more — his desire would probably be settled with the explanation, ' Do you want the earth ?' But then, of course, we are merely an isolated and unpolished community." Medals and Medals. — The Journal of the Photographic Society of Philadelpliia lias the following very sensible remarks on the medal question : — " The photographic journals of recent issue seem to. be unanimous in deploring what has been termed the 'medal nuisance. 182 THE BRITISH JOUR>fAL OK PIlOTOaRlPflY. [March 24, 1893 A small deluge of 'metallic honours' has apparently been poured on the heads of English photographers, and it does look as though the Matter had been overdone. Is this a reason, however, why medals should be abolished ? To us it seems that, if our leading societies treat the evil in the right manner, it will cure itself. If little ex- hibitions continue to award big prizes in large numbers to 'toy photo- graphers,' will not the public quickly appreciate the fact that these awards are of no value, and, instead of asking an exhibitor, ' How many medals have you won lately ? ' the question will be, ' What medals have you won?' The medals at our most important ex- hibitions here and abroad are ."till as hard to win as ever—or probably harder— as the amount of fine work produced increases each year. In this country, three of the leading societies have made an agreement which limits, so far as they are concerned, the number of 'open' competitions to one each year. All photographers of the world are invited to take part, and each year the invitation is more generally accepted. At these exhibitions the very highe.st standard of excel- lence is maintained, and the awards have a value which will never grow lees so long as this aim is kept in view. The question may be asked, however, ' Are not the conscientious and diligent workers, who ■are not quite up to the ' highest notch,' entitled to awards of some kind?' 'This point has been met, where it should be, within the ■•' domestic circle ' of the societies. Local annual exhibitions are now held in our principal societies, the competition being confined to their •ewQ members, and awards of diplomas, or, in some cases, medals, are made. These awards should not be numerous enough to become cheap or easily won, and should always be awarded for decided merit of some kind." Viewing" Photographs by Transmitted Xilg-ht.— A recent American invention embodies " a simple and improved method of treating photographs, drawings, crayons, prints, &c., whereby the picture is protected, and is adapted for exhibition, either as a surface picture or as a transparency. A photograph, drawing, or print, is imposed upon a sheet of translucent material, such as paper or thin cardboard. Over the surface of the picture is secured, by means of a suitable translucent adhesive substance, a protective sheet of mica or other suitable material, which will not destroy the flexibility of the mount, and which is sufficiently transparent to render the picture at all times clearly visible. Upon the rear side of the translucent sheet upon which the picture is imposed is placed another sheet, preferably also of translucent material, upon which is printed or painted the natural or desired colours of the picture subject. The colouring is visible unless the picture is viewed, by transmitted light, as a trans- parency." Z*luoreBcence. — Professor L. H. Laudy, before the Society of Amateur Photographers of New York, recently entered into a dis- cussion of fluorescence, and described the experiments of Sir .John Herscliel with an acid solution of sulphate of quinine. It was found that such a solution, colourless by ordinary light, was opaque when viewed by violet light. Professor Stokes made many experiments on this subject, and found that in fluorescence the length of the light wave is increased, and its velocity of undulation is diminished. The vibrations of the ether in the incident ray appear to excite disturb- ances within the complex molecules of the fluorescent medium, whereby new vibrations are excited in the ether, different in period from those of the incident ray. The portion of the light which has produced this molecular disturbance is used up or absorbed, and thereby lost to visible perception. By this means we are enabled to make the invisible visible, to bring out that portion of the spectrum that, to our eyes, produces no visible image. A design, traced on a card by means of such an acid solution of sulphate of quinine, when dry, is scarcely visible, but a photograph of the same reveals the design in sharp contrast. What a Retoucher Should XLnow.— In the course of a paper in The Art Amateur on "An Occupation for Women," Mr. George G. Rockwood says : " A retoucher should have some know- ledge of light and shade in pictures. He should knoV something of the value of a high light or a mass of dark, and should note carefully 1 how the light has fallen on the sitter, also whether it is a direct light or a reflected one. This knowledge is especially necessary where he is to supply lights that are entirely lacking in the negative. Sup- pose he finds that his print is flat and tame : clearly, the way to improve it is to put in some lights here and there. Perhaps the hair may need a few sharp lines, being careful to follow the curves of the locks, or the modelling of the face may be strengthened by a delicate lightening of the prominent portions. Accessories, such as drapery or furniture, often need little skilful lights, to give them character or to add to the general effect of the composition." The American Customs and American Dry Plates. — We read that, when Miss Barnes took back her American plates from her recent trip to England, the Surveyor of the Port decided that she must pay a duty of CO per cent., as they came under the head of " American Glass Manufactures Improved Abroad." The duty was paid under protest, and a letter written to the Secretary of the Treasury at Washington brought about a reversal of the ruling, on the ground that the exposure of a plate did not consti- tute sufficient evidence of its improvement, many of them being ruined by this treatment. RULED VERSUS GRANULAR GRATINGS. I SEK, in your last week's issue, " Cosmos " alludes to the method I recently described of makin^- gratings by photogriiphing a grained surface under suitable conditions of fighting. 1 feel inclined, with another of his admirers a few weeks back, to say, " Oh, that I could write like ' Cosmos ! ' " but, as I cannot hope to do that, I must trv and explain in plainer language why I described that method, and why I use it instead of — I will not say " prefer " it to — the ruled screen. If my cosmopolitan friend does not agree with me, I trust he will not write me down an " unalterable " one, to use his latest term of endearment. I am prepared to admit that a properly prepared mechanically ruled screen is better for the purpose I had in view, and to which " Cosmos " also refers ; but I cannot agree with him that " more evenness and regularity of grain would be likely to he obtained by mechanical ruling " than by the method I described, in the hands of an amateur, at any rate. Mechanical ruUug requires machinery or appliances of the most delicate and perfect character, and these are not found in the possession of photographers, either amateur or professional ; and, if they were, something more is required than the mere ruling to produce a usable screen. Some years ago an acquaintance of mine, who was connected with the photo-mechanical printing business, showed me a ruled copper plate, not larger than a quarter-plate, which he had had specially prepared, and which had cost him, he said, 10/. The difficulty was that, perfect as was the plate itself — and it was the finest piece of ruling I think I ever saw — he was utterly unable to use it, mainly on account of its extreme fineness, and he came to me to help him to do it by photographic means. But I too failed, for ink impressions upon the most highly surfaced paper were too tine to copy, the contrast between the lines and paper being so faint. We tried printing direct on to thin sheets of gelatine, and even on to stripped collodion films; but here the difficulty was to get the ink to " take " evenly to the support. I have seen samples of very fine ruled screens on thin, trans- parent, flexible films, but do not know how they are produced, and their price is prohibitive, running to about two shillings per square inch, or, say, about twenty-five shillings for a quarter-plate size. I should think they must be photographed direct from rulings on a much larger scale, which means a tremendous amount of labour and the extremes! skill. I need not say that for this purpose absolute regularity — using the adjective it its strictest sense — is necessarj' ; the slightest error in spacing even a single line, or the least variation in pressure, spoiling the whole screen. The difficulty of producing even a quarter-plate grating with 100 or 120 lines to the inch by hand ruling, even with the aid of a machine, may be imagined even by those who have never tried it, which I have not. Possibly " Cosmos " has. 1 have tried a method described in the Joubnal two or three years back, consisting in making a line of minute perforations in a strip of tinfoil, using a finely cut file upon which to lay the foil while a sharp point is passed over it with slight pressure in the same manner that the printing cliche is made in Zuccato's papyrograph, and using this March 24, 1893] TnE BRITISH JOURNAL OF rilOTOGRAPHY. 18.1 perforated strip to form a series of fine lines by drawing it across the surface of a sensitive plate. The principle is perfect, but in practice it is extremely difficult to avoid missinjf one or more perforations in a line of any length, and, as I have said, the least irregularity spoils the -whole thing. . , . . Now, in my makeshift method, there is no attempt at regularity, in the sense of mi-clianical or mathematical regularity, but a grain of a fairly uniform character, in which, from the absence of any attempt at mathematical precision, the faults, if any, are not so noticeable. The grain, too, when photographed, is represented by a vast number i>f minute points with softened edges, which act as minute " vignetters," and so fielp to add perfection to the gradation, even when the grain is comparativelv coarse. In other words, one of these minute " holes," when printed "under a hiyh liyht, would be represented by the merest pin point, but, if submitted to the far longer exposure it would receive under a transparent shadow, would perliaps increase to the dimension of a decided dot. In printing on albumenised paper, with «n evenly ruled screen, a similar, though not so marked, effect is produced. Such is ray reason for using the plan I described, not because I consider it superior to a ruled grating, for I do not, for the purpose, at least, to which I apply it. In conclusion. I agree with "Cosnios," tliat, if photographers only appreciated the effects that can be obtained in this manner, they would be inclined to introduce them as a stimulant to business. ^^^ Lindsay. AERIAL PERSPECTIVE. (American Journal of Photography.) Thk matter of focussing the image upon the ground-glass or focussing screen of the camera, with regard to a determination of the amount of definition in the photograph, is so important a one in its relation to artistic effect, that we feel we may, without apology, be permitted to supplement the excellent ariicle by Professor W. K. iiurton, " The Stop to Use," published in the November number of this Jouknal, by a few remarks which may make more intelligible what Professor Burton evidently feels to be the case, but it is not clear enough upon to assert as definitely as he perhaps should. Objects, as we see them in reality, in addition to extending on a plane parallel to our eyes, also extend towards us and from us, and as one object after another Ls added to those constituting the scene before us, there is an actual recession which, as in the ca^e of landscape scenes, if we would travel from our point of sight to the extreme boundary of our scene, would often take us very many miles away from our starting-point. This continual receding of parts, which is often spoken of as the natural perspective of a view, is so common to us that it does not foim a matter of thought, or arrest the attention in any way, until we come to see a representation of such scene or view upon a flat surface, as in a drawing, or painting, or photograph. Then it is that we feel the shortcoming of art, which cannot in any way advance or recede beyond the surface plane of the canvas or paper, except as in the case of scenery in theatres ; and yet this very shortcoming contributes one of the greatest beauties and features of attractiveness in a well-executed work of art, because by the art of the painter is overcome the appearance of want of relief, and the very deceptiveness of that which he presents to our vision adds to its charm. It is the knowledge of this fact, and the effort of the higher class photographer to vie with the painter, which has given rise to the discussion which we see continually in progress of the effect of cer- tain alterations of focus in portraying scenes with the camera to bring about, if possible, this perspective effect. There are two things upon which the painter mainly relies to bring about the appearance of recession. The one, perspective, which is really the diminishing in size of objects, under certain absolute laws, as they recede from the eye, which is called linear perspective. The other, the intervention of atmosphere between the receding passages, which is known as aerial perspective. The former is unvarfinjj, the rules being the same under all conditions, whilst the latter is simply accidental, varying with the conditions of the weather and other un- controllable circumstances. In addition to these two means within the power of the painter to produce his perspective deception are others, of minor importance, though often made use of, such as the choice of bold features in his foreground, brilliant lights, deep shadow touches, and coarser or more vigorous handling with his brush or pencil. Some of these may be made available by the photographer, others not. The chief reliance of the landscape photographer for the attain- ment of the effect of retirement in the receding passages of his picture must be the intervention of atmosphere ; and here, again, is a nice point, for there must be just enough of such haze to bring about the desired effect, He cannot, as the painter does, at his will, change and vary, perhaps bringing in more here and clearing away there, thus sharpening and heightening hia effects — he must choose a time when there is such a prevalence of haziness as precisely suits his aim. Not too much, because then it will be impossible to attain a sufficient amount of detail in his foreground before his distance will have been irrevocably over-exposed, and not too little, or he will find bin distant features faihng to retire, and his perspective effect will b« lost. There is a continual complication in this matter of effect of reces- sion, between studio or group photography and that of open land- scape views. In the former much more may often be conveyed by alteration of focus than in the latter, because the effect of blurring is much greater in looking at an object a few feet from the eyes, of other objects in the rear of it, than is the case in takinff a comprehen- sive out door view. Therefore the act of vision is better accom- modated by the nature of circumstances. In the case of groups, and what are known as picturesque fore- ground bits, wherein the whole subject pertains comparatively to the foreground, atmosphere can have little or no inlluence in the matter, and a blurring of the background may do much in the way of ac- centuation of the principal feature of the work. Let us especially note here, however, that such blurring by unaccentuated focus can have little benefit when the background features, are very marked in light and dark, or vie in size and form with the principal feature, or are ill-shapen. When a really fine picture is desired, such must be avoided. Some painters, more especially modern, have done much in giving relief to their figures by finishing the latter highly and painting whatever may have formed the background, even though it were near objects, in a blurred manner. We recall some work by De Koninck as especially happy in the effect of relief produced in this way, but the background features were so chosen as not to vie too much with the subject figure. Backgrounds so treated — that is to say, blurred by being put out of focus — must be of such a character as to be considered background solely. Whenever any of the background objects assume sufficient importance to be in any way a prominent part of the picture, it becomes necessary to accentuate the focus sufficiently upon them to make them distinct. To return to landscape work : In order to attain the best perspective effect, we must necessarily choose a time for taking our views when there is just that nice amount of haziness which will give a duo softening of each retiring passage of the work. Only the most careful observation and continual practice will train the photographer in this matter ; not only, as we said before, because the precise amount of obscurity must be determined, but also because its character will make much difference, there being a certain bluish-white, smoky atmosphere prevailing sometimes, which will much more potently affect the sensitive film than will be the case under other conditions of murkiness. Tliere can be no attainment of this desired artistic effect so perfect as that of taking a view under the most favourable atmospheric conditions. No simple blurring of distance by imperfect focus will attain the desired aim when atmosphere is entirely absent. Our remarks must be taken in the true artistic sense. We are well aware that this quality of atmospheric perspective is understood by but few in this country, and even in an admirable little work recently published in Paris, upon orthochromatic photography, the author gives two examples of an extended view with distant mountains and middle-distance town, under what an artist would consider a favour- able atmospheric condition, to show how much superior the view is taken upon the orthochromatic plate, because the ap^arance of haziness is entirely overcome by it, and the town and distant mountains show up in all the distinctness of detail which would per- tain to a clear atmosphere. The best English photographers are working in the true artistic way, and those who are relying upon good composition and light and shadow, with the proper amount of atmosphere, are having the best success, some of those who have relied solely upon alterations of focus to attain their aim, notably Mr. Emerson, having given up in despair. Xanthus Smith. THE INFLUENCE OF DEVELOPMENT ON GRADATION. Many of those photographers who carefully study the journals have been, during the last few years, in a state of considerable doubt and uncertainty as to whether thev have any power of controjlinjf and improving the gradation of their negatives by means of suitable treatment in development. That such a power existed had been 184 THE BRITISH JOURNAL OF PHOTOGRAPHY. [Marcli 24, 1893 regarded as a well-established fact, the truth of which was sufficiently confirmed by the opinions expressed on the subject by the best authorities on photo^aphic matters, as well as by the ordinary experience in the dark room ; but, in 1890, the publication of Messrs. Hurter & Driffield's paper, with the striking and interesting experi- ments therein described, showed a strong case against this generally accepted belief, and gave rise to much doubt in the minds of many readers. Dr. P. H. Emerson was so convinced of the truth of the conclusions arrived at by those experimenters that he entirely altered his views in consequence, in regard to the art side of photography ; and others, while less hasty in fully accepting the suppoaedproof that no modification in gradation could result from variation in development, have still felt that the experiments of Messrs. Hurter & Driffield could not be ignored, and that confidence in the older theory was a good deal shaken. As I was one of those who thought so, and having written a short article on the subject in the autumn as a con- tribution to The British Journal Photographic Almanac while in that rather unsatisfactory state of mind, I decided to undertake a few experiments in order, if possible, to throw some light on the matter; and as the result as regards myself has been to clear away all doubt, an account of my experiments may, perhaps, be interesting to others. . Some of Messrs. Hurter & Driffield's critics have argued that their experiments were unsatisfactory because of the shortness of the range of exposures tested (viz., only those between 10 and 80 C.M.S.), and can scarcely be considered exhaustive. It has also been pointed out that the developers used did not vary sufficiently in constitution, and that considerably greater departure from normal proportions would be made by a practical photographer who wished to greatly change the character of the gradation of a negative in consequence of a known error in exposure. I therefore endeavoured in my experi- ments to cover the whole range of sensitiveness of the plate, giving exposures varying from those which were only sufficient to produce the smallest appreciable density up to those which approached (or entered) the " period of reversal," and, in developing, I went equally to extremes. Pyro and ammonia was used (except in one experi- ment), that being the developer which is generally understood to give the greatest amount of control, and, in settling the proportions in which the ingredients were to be mixed, I was guided by the valuable and instructive series of experiments (quite inconsistent with Messrs. Hurter & Driffield's conclusions) which Mr. W. K. Burton described in 1885, choosing those proportions which had given the most and least detail respectively among the mixtures which he used ; but I found, in the latter case, that it was necessary to slightly increase the amount of ammonia to suit the plates I was using. These plates were the Ilford ordinary, which I believe are pretty regular in quality and easily obtained. A few preliminary sensitometer experi- ments gave pretty clear evidence of different action on the part of two developers, and I then proceeded on the lines laid down by Messrs. Hurter & Driffield. My first experiment in that way left no doubt whatever that complete alteration in the character of a nega- tive might be produced by different treatment in development, but, as the two next were more satisfactory in some respects (especially in being much cleaner in the unexposed parts owing to my having backed all plates after the first experiment) I will omit details of the first experiment, and give particulars of the two next. Five ex- posures in separate patches were made on " plate B," each being ten times the length of the previous one, and varying altogether from 1 C.M.S. to 10,000 C.M.S. The plate was then cut (of course, lengthways) into two pieces, which were soaked a short time in water, and developed separately in solutions mixed in the following pro- portions : — No. 1. I'yrogallol J grain. Sulf hite of soda 2 grains. Bromide of potassium i grain. Ammonia ■ 2 minims. Water 1 ounce. No. 2. PjTogallol 2 grains. Sulphite of soda 8 „ Bromide of potassium 2 „ Ammonia 1 minim. Water 1 ounce. One strip was developed in No. 1 for two and a half minutes, and tlie other in No. 2 for ten minutes, but the action being rather slow, the ammonia was then increased to one and a half minims jier ounce, and development continued five minutes longer. " Plate C " was ex- posed in the same manner, divided into halves, and the strips treated as before, except that, in using the No. 2 developer, no addition wa* made to the ammonia, but the strip was developed for thirty minutes in solution containing one minim per ounce. The results produced were similar in both cases, the strips which had been through similarly constituted developers being very much alike ; but the two halves of each plate showed great contrast towards each other. The No. 1 developer was clearly superior in the 1 C.M.S. patches, having brought out good, substantial density, and such as would show up well in the print if it formed part of the detail of a negative. When developed with No. 2, these patches were certainly just visible, but so very thin that the amount of deposit there would evidently have no printino; value, and would be quite useless in a negative. In the 10 C.AI.S. patches the densities were much alike Ln all strips ; but, in the results of longer' exposures, great differences again became apparent. As developed by No. 1, the densities of the 100, 1000, and 10,000 C.M.S. parts were weak and thin, and hardly appeared to differ when judged by mere inspection, although the photometer showed that density had increased with exposm-e. On the other hand, when developed with No. 2, these patches showed good contrast at each stage, and those representing the longer exposures had great opacity — strikingly different in appearance from corresponding parts of the companion strips. The experiments showed, therefore, that where a negative had received only an instantaneous or very short exposure, in which the light acting on the various parts of the plate had ranged from about 100 C.M.S. in the brightest parts down to some fraction of a C.M.S. in the shadows, that then the No. 1 developer would be much preferable to No. 2, as the more weakly lighted parts would have a reasonable amount of deposit, and the high lights would not be over-dense ; so that, if sufficient density were not obtained in developing the plate, a good negative might, at any rate, be made by intensifying. But if the exposure were full, so that no part of the plate had received less than, say, 10 C.M.S. of exposure, then it is clear from the above that No. 1 would give an entirely worthless negative, and No. 2 a satisfactory one. It is evident that these results are quite inconsistent with the principles advanced by Messrs. Hurter & Driffield. If the densities resulting from one method of development had been greater at each step than the corresponding ones produced by the other, it miglit have been somewhat difficult to prove that more prolonged development of the weaker strip might not, at a certain stage, have brought all its densities equal to those of the other half ; but, where we have some parts denser on one half and some denser on the other, it is clear that no prolongation of develop- ment or after treatment by intensification could ever have produced the same range of gradation on both sides. A simple comparison of the strips seems sufficient to prove the case, but photometrical examination still further strengthens it, and is interesting as showing, in figures, how great the difference is. I have examined the strips in a photometer, constructed according to the directions given by Messrs. Hurter & Driffield in their original paper, very slightly modi- fied, and although I have, so far, had but little practice in photo- metry, I have worked carefully, and believe my figures are fairly accurate. The following table gives the densities found, and the ratios between the densities, in each plate of the parts treated with No. 1, and those treated with No. 2 : — Plate B. Exposure, Plate C. Exposure, C.M.S. Deve- Deve- C.M.S. Deve- Deve- loper loper Katio. loi)er loper Ratio. No. 1. No. 2. No. 1. No. 2. 1 •29 •09 •31 1 •30 •12 •40 10 •70 •70 1-00 10 •78 •75 •96 100 •95 1-58 l'()6 100 1^01 1-41 1^39 1,000 1'05 200 1^'JO 1,000 109 1^83 1^68 10,000 1-14 2-19 1-92 10,000 1-19 2^21 I'Sti The greater density giveL by the No. 1 developer, in the case of the 1 C.M.S. exposure is well shown by the table, and 10 O.M.S., in each case, appears as having about equal densities on both halves of the plate ; but the great superiority in density brought out by No. 2 for the longer exposures then becomes apparent, and increases at each step till, in the 10,000 C.M.S. patches, differences are shown amounting to a density of 1 — that is to say, the strips develoj;ed wi'.h No. 1 allow ten times as much light to pass througli, at that part, as do the corresponding strips. I need make no remark as to the " ratio " columns, except to point out that, if March 24, 1893] THE BRITISH JOUUNAl. OF PHOTOGHAPIIY. 186 Messrs. Hurler & Driffield's principles applied, the figures in those columns should be practically identical for all exposures on the same |tlate. II. J. Channon. [To be continued.) OX THE I'KODUCTION OF BLACK AND WHITE NEGATIVES BY JMEAXS OF AUTIFICIAL LIGHT. IV. Ix a previous article I referred to the influence varying degrees of tenipeniture of the developing solution had upon the plate. A perfect black aiiy Mr. Middleton, with the help of notes which accompanied them. Very interesting they were, 'showing old and new buildings, landmarks, and busy streets, while the third set were perhaps the more delightful pictorially. Fine mountains, streams, and wooded scenery evidently aboun<08ition in one or the other by careful comparison with the original print. Supposing such an idea were put into practice, would it meet with approval? To the man who fears a comparative test it would not ; but to the genuine assistant it must, because of the secure footing it offers him. Some one asks, " By what means ? " When a retoucher is out of work, instead^of advertising, he sends up a fee and has his name placed upon the "open list." Any employer wishing for a man of ability sends in a fee and has his name placed upon the " Open List." Every employer wishing for a man of ability sends in a fee and obtains a copy of the "Open List." Selecting what grade or position he pleases, he corresponds with one or another, and is shown the piece of work that secured the position ; being satisfied as to ability, the rest is easy. Such, then, is the rough outline of a plan, the strong point of which is, it once started, it must act and react upon employers and employed — employers taking to it as the best means of obtaining genuine abihty ; assistants taking to it as a means of proving their genuineness. The greatest fault will be found with it as a species of monopoly, though surely the legitimate worker has a right to a monopoly that will exclude none but fools and rogues. I fear Sir, that, should you consider this worthy of publication, I shall have already occupied too much space, although I have written but a rough outline of all I would say. The details, however, would present little difficulty should the rough sketch meet with approval, and my apology must lie in the importance of the defence of the honourable portion of a not now too honourable profession. — I am, yours, &c., March 21, 1893. N'Importe. ["A JIAED CASE." To the Editor. Sra, — Would you oblige me by giving your opinion on the following, I went apprentice to a photographer on September 10, 1887, and was bound January i), 1888, and came out of my time January 9, 1892— serving four years' apprenticeship. For three years I took no photo- graphs, then he told me if anybody came while he was out I could try my band. I did so, and during the last year I took about thirty-five sitters, mostly i-arles, and one cabinet group of three sitters. Some of the thirty- five I took when he was in ; he did the arranging of positions, and I the focussing. I never did a bromide enlargement, and only a few cabinet-size ontdoor views. He does not do his own retouching, so I tried it at home on tbeqniet, and got on fairly wellafterreadingMr.KedmondBarrett'swritings an the subject ; toning and printing I had pretty well practiced ; very little, indeed, practice at mounting. My principal work was dusting, looking after tires, and filling up picture-frames, and suchlike work. Taking the year all round, he does a good trade and a good deal of picture work. My wages were 2s. M. for the first year, 3«., is., 5«. When I came ont of my time, he asked me to stay on with him for a year or so, so that he could push me on. I consented to do so, for if I lelt so minded to take another place, I could not have done so, owing to my knowing so little. He said he would take another apprentice, and keep me to the business. He said he would give me 10s. a week for the first six months, and 12s. for the next. I then told him that I could do a little retouch- ing. Ho said I should try my band, and, if successfal, bo would give me a little extra. The first week I got 12«. , next lit., next 10s. tjti., next 13s., then 1.5(. ; now it has got to 17s. a week. He only took an apprentice last week. I only took five sitters during the fifteen months, very little outdoor work— only a few traps and a chnrch, I have never taken a whole-plate or a 12 x 10. I never tried to do a bromide enlarge- ment till last week ; in fact, instead of improving myself, I lost what little bit I did leatn during the last year of my apprenticeship. Once a couple came to be taken together, and my employer was at the back, and I went into the studio with them and started taking, and he came in and stopped me, and said before them that I had no business starting takini; them when he was at home ; it was all very well when he was out. Whether right or wrong on my part, he ought not to have spoken to me like that before them, for them to tell it about to people. A few weeks ago I asked him to push me on, an time was getting on, and there was a. deal of opposition in our trade, which made it more reason why I should try and learn more. He said he could not see how he could do any different, as nobody came when he was out, and people liked him to take- them when he was in. Since asking him I have not taken anybody. He does all the operating himself. This is a large county town, and we have plenty of the working class of people in, but not even them does he let me take. In fact I am in such a state that if anybody came now and he was out I could not take them, I should feel so strange, as if I taever had taken anybody before. Of course I feel thoroughly disheartened, and my time is no pleasant one, as I have no prospect before me. Should yon advise me to give it up altogether and turn to some other trade, as I cannot take another situation, as I know so little, not one-quarter as much as I did when I came out of my time, because what little I did learn I have forgotten ? His daughter has been away to learn retouching, finishing, Ac, and she is coming home in September. Of course he will not want me then. If I took every sitter from now till then, I should only just about feel competent of doing anything like at another place. Sorry I have made my case so long, but it will greatly oblige me by your opinion. — I am, yours, &c. A. E. T. March 20, 1893. iSicl)ange iffolumm *^^* No charge is made Jor inserting Exchanges of Apparatus in this column ; but none will he inserted unless the article wanted is definitely stated. Those \oho specify their requirements as **a7iy thing tise/ul" mill there/ore understand (he reason of their twn-appearance. The full 7iame of the uiloertiser must in all co^es be given for pahlication^ otiierwise the Exchanges will not be inserted, WaQteycl« ridtr of ScoUaiid, and lon/««sumai boxer; Joseph KnowUs, trainer ; and Arthur Hto6erson, assistant trainer. H. Mace, A. McCann, and others. — In our next. Powder. — The powder process is folly described at pages 417, 433, and 449 of our volume for 1888. 192 THE BRITISH JOURNAL OF PHOTOURAPUY. [March 24, 1893 C. N. Frith. — Pressure of other engagements prevents us from availing ourselves of the honour. Thanks, nevertheless. G. H. DuNMOBE. — Kemit one and sevenpence and three copies of the photograph to our publishers, who will effect the registration for you. A. Z. (Leeds). — If it is simply a monogram you have on the cards, no licence is needed ; but if it is a crest, then a licence will be necessary. Sorgeon-Gexeral Cook. — 1. At the office for the sale of Patent Specifica- tions, price 8d. 2. Mr. Andrew Pringle's address is Cromwell House, Bexley Hiath, S.E. P. P.— If the prints are made quite dry they will not stick to the burnisher. But it is a good plan to lubricate them with a solution of Castile soap, one or two grains to the ounce of alcohol. A. E. T.— It is quite true that a patent was applied for for a " Willesden Paper" for photographic pictures. But, so far as we know, it has not been put upon the market. Why we cannot say. Don. — -As the marking can be seen on the plates before they are exposed, it is clear they are not due to carelessness on the part of the user. If the marks are in the film, there is no way of avoiding them when developing. . Welford. Visitors are welcomed. Croydon Photographic Exhibition. — This Exhibition, which opens on April 5, promises to be most successful. Messrs. B. Gay Wilkinson, T. M. Brownrigg, J. Gale, and John A. Hodges give special lantern displays on the four evenings during which it is open. The demand for the prospectuses has been so great that a rejirint has been necessary. Our readers should note that Saturday is the last day to receive notices of entry, which .should be sent (no forms iiece-ssary) to G. R. White, 55, .\lbert-road, Croydon. Vanderweyde's Chicago Exhibits. — Mr. Vanderweyde is evidently deti-: mined not to occupy a .secondarj- position at the "World's Fair." He i sending nearly forty of his choicest works; many of these demonstrate tl advantages of his photo-corrector, which he has now brought to a state of pe; fection or almost so. The salon in which they are to !« exhibited is richl • furnished and complete, including carpet, and, being made portable, is to 1 - jiacked up here ready to be set up. The most imposing of his pictorial colic tion is a truly fine work of art, the subject being Ili/patia invoking Apnlln It is eight feet in height, and, so far as the figure itself is concerned, is quit.' untouched. In this noble work the artist has, to our thinking, exceedc'I himself. A Society FOR Beverley. — A meeting of amateurs was held last week at tin- Church Institute for the purpose of consideri^ the desirability of foniiing an Association for the town and neighbourhood. The Rev. F. J. Hall was voted to the chair. After some discussion, in which it was stated tliat the iiumbfi n; amateurs locally was about fifty, and that a good organization could be ii; augurated, it was uiianimotisly decided to form a Society under thedesignatii'- of the " Beverley Photographic Society," and it was further agreed that tl first field day be on Easter Monday to Bishop Burton. Any pamphlet- samjiles, society-working rules, &c., will be gladly received by the Hoi:. Secretaries ^ro tem., J. J. Morley and A. Pickering. OONTIiNTS. ELEVATING THE POINT OF VIEW .... 177 THE WEI.SBACH LIGHT FOR STUDIO WORK 177 COMBINATION PRINTING 178 TEiMI'EUATURE IN THE DARK ROOM 180 GLYCIN. By COLONEL J. WATER- HOUSE. I.S.C 180 AMERICAN NOTES AND NEWS 181 RULED VKItSVS ORANUL.1R GRAT- INGS. By W. LINDSAY 182 AERIAL PEBSPECTn'E. By XANTHUS SMITH ISS THE INFLUENCE OK DEVELOPMENT ON GRADATION. By H. J. CHANNON 1S3 pAflF ON THE PRODUCTION OF BLACK AND WHITE NEGATIVES BY MEANS OF ARTIFICIAL LIGHT.— IV. By T. N. ARMSTRONG Is' NOIIMAL ASK SOLARISING DEN- SITIES. By HUGH IIREBNER l"-' Bough paper. By henry w. BENNETT V'' AN ATTKACTIVE "OPTIMUS" EXHI- BITION M RECENT PATENTS 1»7 MEETINGS OK SOCIETIES 18' FORTHCOMING EXHIBITIONS 1»S' CORRESPONDENCE !« EXCHANGE COLUMN Wl ANSWERS TO CORRESPONDENTS lal THE BRITISH JOURNAL OF PHOTOGRAPHY. No. 1717. Vol. XL.— MARCH 31, 1893. :multiple-coated films. It seems nidrc than likely that the subject of multiple-coated films will form matter for interesting discussion for some time to come, since, underljinj,' the fact that such films prove the most effective cure for, or preventive of, halation'that has yet been devised, there is the question as to how the eflfcct is protluced. Is it the mere extra opacity of the double or triple film that prevents the rays of light penetrating to the glass, and to be thrown back again upon the sensitive layer of gelatine, or do the separate films of varying sensitiveness react in some peculiar way, one upon another, in such a manner as to contribute to, if not altogether to bring about, the result 1 Such is the question already raised, which wiU have to be satis- factorily answered. Double films are by no means a novelty in photography, for if we go back to the very earliest of practical dry -plate processes — the coUodio-albumen — we find that that was a double-film process, a preliminary layer of silver iodide in collodion being subsequently coated with iodised albumen, sensitised in a })ath of silver nitrate, washed and dried. There is, however, little analogy between the double-coated film of to-day and that of forty years ago. The former consists of two separate layers of sensitive gelatine, each possessing a different •degree of sensitiveness, while in the older process the sensitive- ness was most probably uniform throughout the whole thick- ness of the compound film, or as nearly so as is possible with any bath film. The lower, or collodion film, it is true, was, per ge, quite insensitive, being prepared in such a manner, with excess of alkaline iodide, that exposure to light before the application of the second or albumen film was said rather to improve the qualities of the plate than otherwise ; but, after recoating with iodised alliumen, and immersion a second time in the silver bath, the sensitiveness of the iodide of silver in the under layer of collodion was restored, and little difference, we imagine, was to be found in the character of the film at different depths. Even when, later on, bromide was introduced into the second film, it is questionable whether any alteration took place in this respect, for the albumen would more or less sink into the pores of the collodion, and form a practically homogeneous layer instead of being altogether isolated, as in the modern compound films. There is, however, one very noteworthy fact that m«y bo mentioned in connexion with the old collodio- albumeniscd plates, namely, that, although they were by no means remarkable for opacity, they were wonderfully free from the defect now known as halation. Some seventeen or eighteen years ago double films cropped up again, this time in a purely scientific rather than a practical form. Captain Abney published the result of a series of ex- periments of his own, showing that if a sensitive film after exposure were recoated with a second layer of washed collodion emulsion, and then developed, an image would be formed upon both films, that which had not been exposed being affected in some peculiar manner by the chemical action proceeding in the other. The two films in this experiment were even more completely isolated than is the case in the modern multiple film, as, in order to prevent the second layer of enndsion dissolving the film upon which it was poured, as well as to enable the two films to be afterwards separated for examination, an intermediate layer of gum arable, albumen, or similar sul> stance, was applied in such manner that the two films were actually not even in contact. It is, perhaps, only right to say that there are those who doubt the accuracy of the observations in connexion with the production of the image on the unexposed film, but from our own trials we think there is little doubt that, under favoiu-able circumstances, it does occur, though there is considerable un- certainty as to what the precise conditions are. We have on many occasions obtained unmistakable evidence of develop- ment on the unexposed film, and at other times, under apparently precisely the .same circumstances, have altoirether failed. So that it may be said there is some doubt as to the possibility of any action taking place between films that are completely isolated — at any rate, in the way of setting up a developing action when there has been no exposure. The reverse effect might possibly occur under precisely similar con- ditions from easily explainable causes, as w-e shall point out later ; in other words, development might be arrested in one film by that going on in another. As an outcome of Captain Abney's experiments, it was attempted to utilise the principle of double coating for the purpose of producing composite films combining qualities that coidd not be obtained in the same emulsion. Thus, it will be rememliered, by those of our readers whose acquaintanceship with photography dates back to the period mentioned, that the great difficulty with collodion emulsion workers was to combine extreme sensitiveness with the necessary vigour required in a printing negative. Very sensitive emulsions could be made- — not approaching, it is true, the films of to-day — but they were of no practical value, owing to the impossibility of intensifying the images they produced by any known means. On the other hand, it was quite easy to got any desired amount of vigour in an emulsion, but unfortunately only in conjunction with com- parative insensitivencss. Acting on Captain Abney's suggestion, it seemed but natural j that, if a plate were coated, first with a slow and vigorous 194 THE BRITISH JOURNAL OF PHOTOGRAPHY. [March 31, 1893 emulsion and afterwards with one of the rapid and delicate type, the difficulty would be solved, and such in a partial manner proved to be the case ; but, owing to the troublesome character of the double-coating process, the matter was never at that time seriously carried out. In more recent years, since the introduction of gelatine emulsions, numei'ous suggestions have been made, and, we believe, at least one actual com- mercial attempt to introduce collodio-gelatine plates — that is to say, double films of gelatine and collodion ; but, for one reason or another, most probably the e.\tra trouble, the matter has never been followed up. "While the scientific aspect, if we may so term it, of double films has been altogether neglected, the various attempts to utilise the principle practically have hitherto failed, and it is only at the present junctm-o, when success has been secured in a direction not hitherto looked for, that interest is again aroused. The special claims made for the modern composite films are great latitude of exposure and capability of resisting halation, and both of these seem to be well fulfilled. The former partly covers the ground attempted some fifteen or sixteen years ago, when it was endeavoured to combine rapidity with density, for the result is arrived at by the same means, namely, combining two emulsions of widely different sensitive- ness, and so far the rationale of the behaviour of the compound film is intelligible. But it is on the question of halation that discussion will arise. This formed no part of the argument in past years, if for no other reason than that a very large number of collodion films would have to be superimposed before the opacity of even a single gelatine film would be reached, and, indeed, mere opacity was not then looked upon as a cure for the defect. Even now, as shown by Mr. Stillman's article of a fortnight ago, tliere are those who doubt it, while Mr. Sandell's letter of last week expressly states that mere thickness of film does not prevent halation. In order to thoroughly ventilate the question, it would be interesting to experiment with films that could be easily sejjarated after development, in order that the action of one upon the other might be carefully studied. For this purpose we would suggest a gelatine film on the top. of a collodion film ; and, if a triple film be required, let the first, or lowest, be of albumen, sensitised in the silver bath, and thus rendered quite insoluble. Over this might come a collodion emulsion film, as sensitive as can be made, and over that, again, a layer of gelatine emulsion. With such a combination we should have certainly a wide enough variation in sensitiveness, and, for purposes of examination, any of the layers could be easily dissolved off without affecting the others, which is scarcely the case when gelatine lies on gelatine. The effect of a double film, as now used, must not be con- founded with that referred to in connexion with Captain Abney's experiments. There, an exposed film was supposed to transmit some action to an entirely unexposed one during development ; in fact, an electro-chemical action was supposed to be set up. In the modem double or triple film each layer receives a certain exposure, which may be sufficient for the more rapid, but not for the others, and amongst them they make a sort of com- promise. Whether the rapid film is able to impart extra energy to the slower film in contact with it or not is one of the points to be decided ; but we think there can be little doubt as to its power — where reversal occurs — of arresting development in the other film, and it is, possibly, in great measure to this action that the prevention of halation is at least partly due. LENS FOG. In a preceding article on this subject we descanted upon some of the most familiar causes of this little-discussed defect, causes that might be described as mechanical. But even that category was not exhausted by us. Let us next refer to a very evil condition of the lens that is sometimes seen in instruments made by opticians in the foremost rank. It is, perhaps, seen most commonly in portrait lenses, but there are some other particular constructions of lenses in which it is often manifest. We refer to the condition of the external margin of the lens. Too frequently this portion of the glass is simply smoothed in the lathe, and the lens is then burnished or screwed into its cell without further treatment. But we aver that there are very few instruments worked with full aperture where this may not on occasion produce fog. When a lens so defective is used in the open air, or even in a well-built studio, if the camera be placed in such a position as to receive a fair share of light from the sky, a portion of that light will strike this part of tlie lens, and a portion be reflected into the camera and on the plate, and no other result but a veiled image could be expected. Every objective worked with full aper- ture should have each of its constituent elements carefuUy blackened at this part to prevent injurious reflection. An asphalt varnish will, perhaps, be as good a medium as any- thing to use for the purpose, as, when in proper contact with the glass surface, it practically destroys any reflection likely to occur. That a suggestion as to a desirable varnish is not un- necessary is proved by a lens which is before us while writing. It is made by an eminent foreign manufacturer, the posterior combination being of very considerable thickness, and, possibly to lighten the instrument, coned as regards its external figure. If it is placed in the camera without a diaphragm, there is seen such an amount of light dispersed from the inner surface of this cone that it would be utterly impossible to take a good negative with it if a particle of sky light fell upon the instru- ment. A judiciously applied coating of asphalt varnish would destroy all this danger. But we would further add, that the protection would be more complete if the surface were more roughly polished instead of smoothed, and rendered like the ground glass of the camera. Another little-observed form of lens fog, which is almost in- capable of cure, is that caused by internal reflection from the various faces of the lenses on the plate itself, when a very brightly lighted object is before the camera. Who is there who has not attempted, say, a group of sitters against an only available background, a whitewashed wall, and been disappointed beyond measure at the result 1 It is true that some of the fogginess produced under the conditions described is due also to the illumination of the bellows of the camera from the brightly lighted plate, but the main portion is to be credited to the lens. For photographing under these conditions there has been sug- gested as a remedy a preliminary staining of the surface of the plate sufficient to allow the penetration of the image, but insufficient to light up camera and lens with actinic light. Turmeric or logwood solution has, we have been told, been suc- cessfully tried. The sensitiveness is diminished, it is true, but the light sent back upon the plate is diminished in greater proportion ; and so the evil is abated, if not, as sometimes may prove to be the case, entirely cured. We do not remember ever to have seen this kind of lens fog to have been alluded to, but it very often is produced under ignorance of its true causes. We liave often seen another example of lens fog, where the sun strikes the glass surface of the lens itself. March .".I, ISO,*?] THE BRITISH JOURNAL OF PHOTOGRAPHY. 19/; AVhen stopped down and the surfaces quite free from dust, it is possible that no evil may result ; but it is not impossible, for the internal surfaces of the lens, their marginal surfaces, and tiie blacking of the lens tube and shade require to be in a condition perfectly adapted to avoid the kind of reflections wo have treated upon. From all these descriptions of the various kinds of lens fog, there is one obvious moral to be drawn, a large pro- portion of them are entirely avoidable by properly screening the lens. Tn drawing attention to this point wo are well aware that it is no news at all to many skilled workers, but our readers will bear us out that, whenever a body of photographers meet for outdoor negative -taking, the majority of lenses are not so screened, except perhaps by holding the black cloth, or perhaps a black hat, to shade the objectiw. And in studio work how many cameras may there not be seen, in the very first class of establishments, with neither screen nor shade beyond the comparatively narrow brass rim provided by the maker. If every lens — studio and field — were shaded off till nothing could be seen from the lens but the paiticular object or view to be photographed, there would be such an improvement in tbe vast majority of the negatives taken as to amount almost to a revolution in results. The " aoyal " Photogrraplilc Society.— In a long ad- vertisement in a suburban paper, of a local firm of photographers, amongst the list of imperial and royal Exhibitions at which medals have been awarded to them, the Royal Photographic Society of Great Britain is mentioned no less than four times. The parent ' Society is advancing rapidly now, it is true; but we were unaware that it had obtained a Royal Charter, although we believe it is desirous of possessing one. As the town in which this firm is located pos-sesses an energetic photographic club, which is affiliated with the Photographic Society of Great Britain, and whose President is one of its Council, the advertisement will, no doubt, cause its members some little surprise or amusement. K{ Simplicity. — In a recent issue of an evening contemporary, ' which devotes a column to notes and queries, appeared the following: — "Coidd any reader kindly give me a receipt for the wet-plate or positive process." Simple'/ In due course formuliB are given, over a signature that appears in replies to questions on •very conceivable subject. The silver bath is two ounces of nitrate if silver and one drachm of collodion to sixteen ounces of water. Fifty-five grains to the ounce is a little strong for a positive bath, most people would think. The developer contains " galacial " acetic acid. From the wording of the query one is almost led to inquire if the wet-collodion proceas will in the near future only be associated with glass positives. rine Art Ezbibition.— .Vn excellent and highly representa- tive Exhibition of paintings, by most of the leading artists, is now- open at St. Jude's Schoolroom, Whitechapel. It will well repay a visit to the " fur East," as it contains selections from some of the best collections in England. This is the thirteenth show of its kind, and, like all its predecessors, it is highly* appreciated by the East-enders, ;ia testified by the number of visitors, the larger majority of whom, it is worthy of remark, are of the working classes, the Exhibition being opened on Sundays. During the few days it was open last year, it was visited by about 80,000 persons. It closes on the 9th prox. Judging from the specimens exhibited in the show-cases of some of the photographers of the neighbourhood, they woidd do well to visit the Exhibition, and profit from what they will see. The art aspect of photography at the East-end, like that of many other parts, is open to improvement. The Manchester "Spy" and Photogrraphers. — A few montlis back we were the first to commend the «. d. and surrounding conditions ure the chief factors in arriving at a decision, for, within ordinary bounds, the larger a studio is the greater its convenience, and the more complete the control of the lighting. Especially is this so in large groups, as the nearer the group is to the light aperture, if such an expression may be permitted, the more uneven will be the lighting of the individual members composing it. Length of studio is most important for group-taking also, as it is likewise for full-length portraits. It is always advisable to have a full twenty or twenty-two feet at least between sitter and camera, but this must not by any means be understood as the length the studio should be. At the very lowest estimate, two feet should be allowed for the camera, and another two feet for comfortable working behind it. Double these allowances would not be too much. Then, at the sitter's end, allowance must be made for head-rest (still of occasional use in every studio) and for movable backgrounds. For these purposes four feet is the minimum distance to be reckoned with. We thus arrive at thirty feet as practically the shortest length a studio should possess, if it is to be well adapted for the various purposes a professional por- traitist would require it for. A still longer room will naturally offer greater facilities, but when a greater distance than here named i& allowed between lens and sitter it will be found that atmospheric fog — unless the air be exceptionally pure, as in some seaside places — will too often be sufficiently manifest to cause a foggy picture. Under all ordinary circumstances, provided the camera is not too near to cause disproportion or distortion, crisper pictures of single subjects are taken when the sitter is near to, rather than far off, the camera. It need not be said, however, that increased distance gives more harmony of proportion as regards hands and limbs. Breadth of studio, again, is very advisable ; when there is room to spare on each side of the sitter, there is so much greater freedom in arranging accessories, and increased command over the light, that it is easy to avoid that tendency to conventional positions, lighting, and management, so fatal to originality and artistic effect of the work produced. Granted the maximum dimensions in length already quoted, I would, if it were in my power, much prefer to increase the breadth than the length. The next point I have been asked about is the length and thickness of the window bars, the size of the glass, how to j glaze, and other similar subjects. Taking the size of the bars first, j I should say this is entirely a question for the architect or builder; ] but, above all, they should be stout enough. A little loss of light | from these bars or sashes is of no account whatever in comparison j with the danger of leaking and the glass breaking, through the strain ; on the binding material, be it putty or otherwise, which is certain to be incurred when the bars are too light. It is no unfair estimai to say that nearly one half of the leaky skylights in the country ai' caused by tlie frames beiuir too light. Under any circumstanci- it will be necessary, for example, to have workmen occasionally on the roof, and, if the bars cannot sustain their weight without a sliglit bending, it will be found that the next shower, after the glass roof has been so invaded, will discover several leaia- spots. The bars can be chamfered off at the inner angles without seriously reducing their stability. I have adopted that plan with advantage, but otherwise have always made a point of having them sti'ong and substantial. One very valuable recommendation as to the shape of bars has been made which, though I have not tried it, I feel sure must be of considerable use as against possible leakage. It is that a deep groove should be cut into the bars for their whole lengtli on each side on their inner surfaces, so as, in the event of water gaining admittance, to lead it away towards the eaves. It will be observed in cases of leakages that tlie water rarely drops down whei-e it actually enters, it usually " follows " for some distanc' the angle of glass and bar, and \vill then, perhaps, travel alon,. the front face of the latter before it falls. This is one cause ot the difficultv of localising the exact spot where the leakage exists. It will be judged from this thdt I have not been without leakages; though certainly they have been few, and would have been fewer still if my instructions had been carried out by the glaziers. At this stage it will be as well to point out a very important matte: about arranging the roof. Whether for periodical painting, or h< carrying out alterations and reconstructions, the inevitable work man will at times be on the roof, and it will be wise to providi against him and for him. I have experience of the array "t ladders and boards slung on the glass, the time wasted, and tli' March 31, 189S] THE BRI-WSH JOURNAL OF PHOTOGRAPHY. 197 damage done, and for many years past have arranffed a method by ■which this inconvenience could be reduced to a minimum. Each side of my gloss roof is provided with a specially constructed ladder for the workmen to use. The roof of my present studio is a wooden ridge, well protected with lead, and upon this ridge the ladders rest prevented from slipping by a pair of iron hooks, which grip the ridge piece and prevent any danger of slipping. The ladders are alwayn kept .m the roof ready for use, and workmen greatly appreciate the safety and convenience of such an arrangement These ladders have long cross pieces at intervals to rest upon the window bars, and prevent swagging and pressing upon the glass- further, they are guarded on the side next the glass, to prevent a careless foot slipping through, by longitudinal laths. My present ladders are nearly worn out through constant service, and I am hoping to be able in the next to introduce still further little improvements, In addition to these ladders, the skylight bars have permanently let into them, and projecting some distance, strong thick .screws, for the purpose of supporting the long planks which the British workman generally finds it necessary to employ when he is on a roof. This prevents the surreptitious use of a naU or two, which he is to apt to insert in the woodwork to aid in securing his paraphernalia, with the inevitable consequence of starting: a leak. One other point as to workmen on the roof. The studio I built before my present one was on a lofty building overlooking a large yard, over which I had no rights or easements of any kind. I could not build even a pro- jecting spout, nor put out a window. In consequence, to obtain the effect of side light, I made the wall of the studio on that side only four feet above the floor, and then the glass roof shot up sheer and steep till the ridge was over twenty feet high. It was ditficult to get workmen to venture on to it, and when they were there I was so uneasy as to their safety, that eventually I got the builder to erect a kind of iron bar fencing the whole length of the roof against a possible accidental fall, and, further, encroached upon the glass by fixing a narrow wooden pathway for the workmen to pass along, taking care to line the glass for a few inches above it with narrow wooden strips, to avoid breakage by an inadvertent footstep. When this was done my mind was at ease, and I found no difficulty in getting workmen upon the steep roof. At the risk of unduly lengthening my paper, I will here narrate a personal experience. A plumber and glazier had undertaken the job of putting up the fence, and, when completed, I went upon the roof to examine and test it. I was leaning against it ; if it had given way, I should have known nothing about it, for the drop would have been fifty feet on to the flags, and the workman said, " You had better not lean against it, sir, it might give way ! " He had actually made this safety fence of narrow thin iron gas piping, further weakened by cutting the threads for the screws which joined the sections. I was horrified at the risk I had been in, and, I need not say, greatly incensed at the way the work had been executed. Of course, all thi» had to bo taken down, and a soUd iron rod put in its place. It is so entirely possible that others might meet with a similar experience, that it will not be thought a needless encumbrance to have narrated this occurrence. G. Watmocoh Webster, F.C.S. THE INFLUENCE OF DEVELOPMENT ON GRADATION.* My next experiment was principally directed to finding how grada- tion was affected by length of time in development, and again I found reason to beUeve that the conclusions of Messrs. Hurter & Driffield did not apply under the altered and extended conditions under which 1 was working. A half-plate (plate D) was given the same series of exnosures as before, except that the last was increased to 100,000 t.M.S., as I wished to have an example of reversal ; this 100,000 O.JI.S. patch was very distuictly darkened before development. The plate was cut into six pieces, marked with consecutive numbers, and four of til em were developed together in the No. 2 developer for varying lengths of time. The 100,000 C.M.S. patch appeared before any other, and kept the lead for some time. The other two pieces * Ooncladed from page 185. were treated with developer No. 1 . The following table will give the details of the experiment and the resulting densities : — Plate D. Developer No. 2. Developer No. 1. Number of strip. 1. 2. 8. 4. S. a. Strip 5xl^4, Time of 4 10 20 60 2 4 Development. mius. mms. mine. inin». rams. ming. C.M.S. 6 1 -00 •00 •06 •43 •22 •30 •31 g 10 •00 •00 -58 1-44 •57 •87 •80 g 100 •06 •35 1-54 2-59 •80 1^19 1-20 X 1,000 -12 •71 2-08 807 •97 1^30 1-m H 100,000 •19 •76 1-66 2-37 •90 120 1-26 The different action of the two developers is again very strikingly apparent; a comparistin of strip •'! with strips 5 and 6 shows that very strongly. In regard to the length of time of development, Messrs. Ilurter & Driffield's experhiients led them to the conclusion that the ratios between the densities, produced by varying exposures, were always constant, and that the only difference in result to be expected from a long time of development over a shorter one was, that all densities would be increased, but that the increase would always be in the same proportion all through the scale, so that the ratios would still remain unchanged. Now, in the case of strips 5 and 6, where the alterations in time and density are within comparatively narrow limits,that rule proves f airly co/rect; by multiplying the smaller densities by 1"4 (as I have shown in the last column) we obtain figures nearly cor- respondingto those of strip 6. But the strips developed with solutionNo. 3 certainly show no evidence of their being subject to such a rule. In every case, an alteration in the time of development has led to a complete change in gradation, and, so far as any theory can be formed from a single experiment, this one appears to show tliat the parts which have received the fullest exposure are the first to develop and the first to flag. They have a long lead at first, and are always more and more nearly overtaken by parts less exposed as development pro- ceeds. I mentioned that the 100,000 C.M.S. patch appeared before any other and kept the lead for some time ; this is quite in accoi-dance with general opinions, as it has often been noted that, when negatives are reproduced by the reverse action of light, a positive appears at the first stage of development, which is afterwards overpowered by the superior density of the less exposed parts. The figures are quite in accordance with that fact, and show that, up to the time of ten minutes of development, no reversal had taken place. If a negative, therefore, had received .so long an exposure (on an " Ilford Ordinary" plate) that it amounted in some parts to as much as 100,000 C.M.S., it appears that the picture might still be saved and all reversal avoided by treating the plate with developer No. 2 and stopping the action after ten minutes. It is true that the result would be very thin, but still a fair negative might probably be made from it by intensification. By comparing this with some of the previous results, some idea may be formed of the great range of exposures from which it may be possible, by proper treatment, to produce passable negatives. If we suppose a subject to be chosen in which the intensities of the light vary as much as 1 : 1000 between the brightest and darkest parts, and consider firstly such an exposure to be made on it as would give a range equal to -1 to 100 C.M.S. by means of rather prolonged treat- ment with the No. 1 developer, there is little doubt a fairly good negative might be made from it on an " Ilford Ordinary." The tables I have given show some considerable density on the 1 C.M.S. line, and, in another experiment, an exposure of -1 C.M.S. has produced quite distinct though thin deposit ; so that in such a negative we need have absolutelj' bare glass nowhere, and every variation in intensity of light through the picture would be represented by some difference in gradation in the density of the negative. Now, if that exposure had been increased a thousandfold, we should then have only reached a range of exposures of from 100 to 100,000 C.M.S., and it has, I think, been shown that even then the case would not be hopeless. And this is taking it for granted that the piesence of either bare gla&j or solarisation on any part of a negative would be a fatal defect, which is not the general opinion of photographers. Of course the possibility of obtaining the ideal " perfect negative,'' which has all the "values" correctly represented, would not exist in these extreme 198 THE BRITISH JOURNAL OF PHOTgGRAPHY. [March 31, 1893 cases. Messrs. Hurter & Driffield have shown how such negatives may be made, and the principles they advance on the subject are no doubt generally correct, although I think they will have to be modified by the conditions that the developer must be normal in constitution, and the time of development regulated ; but whether the same end may be reached by other means, whether the necessary " period of correct exposure " would be shifted in position under altered conditions such as those I have described, or whether it would exist at all, would require much more elaborate experiments than mine to discover. It is interesting to note how, in the last table, the density of the 100,000 C.M.S. gradually falls behind the others. It is first in strip 2, between 100 and 100v> C.M.S. in the next, and considerably less than the 100 C.M.S. patch in the strip 4 column. The following table will give the details of another experiment in which I endeavoured to test the action of different species of developers. The proportions given of the ingredients represent grains per fluid ounce (minims of ammonia), and, except as regards strips 1 and 6, I think they are in about ordinary working proportions. Sodic sulphite was employed in all the solutions, but, as it was unlikely to affect gradation it has been unnecessary to give the amount used in each case. Plate E. Number of Strip. 1. 2. 3. 4. 5. 6. ■•^■M ION "S NffI i-trHM (MOarH :| j^ Developer. ■S 1 -of, in Jl as O a, 1 •c 1 S 11 II is : i lit *.'S '■ "S g a 5-= '3 &.&.-«!■ HCU 5), I do not find so much variety in the ratios as I should have expected. These densities may be compared more conveniently by examining their ratios when compared with a standard exposure. I have therefore taken 10 C.M.S., which is a fairly regular exposure, and now give the ratios of other densities when those of 10 C.M.S. are made equal to 1, omitting, however, the results of shorter exposures than 1 C.M.S., as the accuracy of such small figures cannot be depended on. Number of Strip, 1. 2. 3. 4. 5. 6. C.M.S. s 1 •26 •24 •27 •23 •21 •07 a 10 1^00 1^00 1-00 l^OO 1^00 1^00 Oi 100 1-43 1^53 1^57 1^62 1^60 2^55 X H 1,000 1-59 1^64 1^74 1^86 1^88 3-70 100,000 1^56 1'29 1'34 1^39 1^67 3-68 The range of exposures used by Messrs. Hurter & Driffield would be covered by the difference between the 10 and 100 C.M.S. lines, and the ratios between these in regard to strips 2 to -5 certainly vary very Uttle, not more than in similar experiments described by those gentlemen; and even on the 1000 C.M.S. line the variation is not great, although eikonogen is found (as it was also by Messrs. Hurter & Drifiield themselves) to give less density th»n other developers. The phenomenon of reversal, however, seems to be much influenced by the species of developer used^ being far less strongly marked when pyro has been employed ; but perhaps it is the alkali used which has the principal influence in that matter. In strips 1 and 6, it will be noticed, the density of the 100,000 CMS. patch is practically the same as that of the 1000 C.M.S. I do not think, however (taking the experiment with plate D into consideration), that this absence of reversal is altogether owing to the composition of the developers. It is probably mainly due to the fact that the action was not carried so far in developing those strips as in the other cases, so that, in consequence, the less exposed part only just reached the same density as the 100,000 C.M.S. patch ; more prolonged development might probably have given the formera considerable advantage. Apart from reversal, this experiment shows little difference in the actions of the various kinds of developers, but I doubt whether other experiments may not give very different results. The experience of Messrs. Hurter & Driffield with para-amidophenol may, very possibly, be repeated in other cases, and what has been found to apply to that one developer, prove to be true of all. That is, that the special action of a developer may be found to depend very much on the quaUty of the plate, so that, while two species may give very similar gradations for equal series of exposures on some makes, they may yet prove to be very different in their effects when other plates are used. In using eikono- gen in the autumn, on a different quality of plate, it certainly seemed to me to have an advantage over pyro and amidol for short expo- sures, which is not shown in this experiment with the "Ilford Ordinary." On the whole, I think the experiment shows that development is, unfortunately, not so simple a matter as Messrs. Hurter & Driffield's experiments gave good reason for believing. Considering that there are now so many varieties of developers, every one of which may be greatly modified by altering the proportions of its ingredients as well as by various additions or omissions, and considering also how great is the difference between various qualities of dry plates, it would have been very satisfactory to have found that, after all, there was a simple rule which applied to every case. But, as that now appears to be more than doubtful, we have scarcely any scientific guidance to fall back upon, and development is likely to remain a mere rule-of-thumb matter, but it is much to be desired that those photographers who have time on their hands will devote some part of it to an attempt to add something to the small knowledge we now possess of the action of developers. I ought to mention, perhaps, that I have in all cases used the expression "density" in the sense adopted by Messrs. Hurter & Driffield, viz., as representing the logarithm of the reciprocal of the transparency. A density of 1 .stands, therefore, for a transparency of y\, ; a density of 2 for a transparency of i\ts, &c. It is the ratios between such logarithms, and not those between the transparencies themselves, which, if Jlessrs. Hurter & Driffield's original principle.s, as described in the paper on Photo-chemical Investiyations, were correct, should be unalterable (after exposure), and not at all dependent on the method of development employed. H. J. Channon, FURTHER NOTES ON QUAIACOL AND ALLIED PHENO- LOID COMPOUNDS AS DEVELOPERS FOR GELATINE DRY PLATES. LPhotographio Society of Great Britain.] In May, 1890, 1 brought to the notice of the Photographic Society of Great Britain, that guaiacol, or methyl-catechol, possessed fair powers of developing dry plates. It cannot be recommended as a practical developer, on account of its very strong smell, and its slow and weak action as compared with the ordinary developers. It has, however, recently been found useful by R. E. Liesegang as a developer for bromide paper prints. In a very interesting paper published in the Bulletin de la Society Fran^aise de I'hotographie, vol. xxxvii. p. 310, Messrs. A. and L. Lumiere, of Lyons, have given some results of their investigations into the relations between the chemical constitution of a large number of reducing agents, and their action on silver bromide altered by light,, and have found that in various bodies belonging to the aromatic series of benzene derivatives, to which most of the ordinary organic dry- plate developers belong, certain conditions must be fulfilled in order that they may possess the power of developing a latent image ott silver bromide. The principal of these conditions are r — (a). In order that a substance of the aromatic series may act as »• developer of the latent image, it is necessary that the benzene nucleus should contain at least two hydroxyl groups Oil or two amidogen groups Nil.,, or even one hydroxyl and one amidogen.. The power of developing also holds good when the molecule con- tains a larger number of groups OH or NH,„ March .11, 1803 1 THE BRITISH JOURNAL OF PHOTOGRAPHY. 199 (6). S\ib8titutions which raav bo effected in the lyroup OH or in the (^oup N n., destroy developing power in all cases in which at least two of tliese groups do not remain intact in the molecule. Now guaiacol I C„nXoH 0 P""*^^"'^ * substitution in one of two hydroxyls, and although Messrs. Lumi&re's first experience as to its developing p when oxidised, shows this power, though it does not do so when pure. The guaiacol used in my first trials in 1890 is now quite brown and oxidised. It is labelled "f/imiacol jmrisa" and was obtained from Dr. Schucliardt, of Gorlitz ; but he prepares a still purer product, which I have not tried. 1 1 would be impossible to obtain here am absolutely pure sample, but a fresher and perfectly colourless sample wliich came from the same source as the first, and is nominally of the same quality, but has been with me for about a year unopened, has also been tried and found to be a very much weaker developer than the first sample was and now is. Whereas the brown oxidised g-uaiacol with potash will develop a well-exposed plate with fair rapidity and moderate intensity, the colourless sample will, under the same conditions, only give a very weak but well-detailed image, even ufter a very prolonged development. From this it appears highly iirobable that an absolutely pure sample would not develop at all, and it is possible that the slight developing action observed may be due to the oxidising action of the air during the prolonged development, as seems to be also the ease with carbolic acid. It may 'be noted also that when first tried the now oxidised sample of guaiacol showed a slight green tint with alkalies, and it now gives quite a dark green solution, while the solution of the fresher sample in alkalies is almost colourless, and shows no trace of green oxidation. In these last experiments the guaiacol has been dissolved in caustic potasli solution, about 1 c.c. of guaiacol to ■■> c.c. of a 10 per cent, solution of the potash, and the clear solution diluted to about .3.3 c.c. It was noticed that the old guaiacol was not so readily soluble as the new. GuAiAC Resix. If the developing power shown by guaiacol be not due to oxidation products, but to some impurity, it becomes interesting to know what that impurity is, because it may possibly be a powerful and effective developer in itself, as it must presumably only be present in very small quantity in the purified samples of guaiacol I have tried. The uature of this impurity will no doubt depend on the method of pre- paration of the guaiacol, as to which I have no information. As this substance forms the principal constituent of beechwood creosote, and may be obtained by fractional distillation from it, the guaiacol of com- merce is probably obtained in this manner, but it may also be produced by the dry distillation of guaiac resin, and by other chemical methods. As regards guaiac resin, I find that a solution of it in aqueous caustic potash solution is only a very feeble developer of silver bromide I IB gelatme dry plates; the developing agent in commercial guaiacol 1 would therefore not appear to be one of the constituents of guaiac I resin in its ordinary state, and we may look for it with better chance j of success in creosote, some samples of which have been found to !' possess much stronger developing powers than guaiacol. 1 By destructive distillation guaiac resin yields guaiacene (0,11,0), gniuacol (C^H^Oj), creosol (C,H,„0„), and pyroguaiacin (C;^n„0,). If the latter product fulfils Messrs. Lumiere's conditions, it might be worth examination. Crkosol a DkVKT.OI'ER. Creosol is a colourless oily liquid, with a strong aromatic odour, not «o pleasant as guaiacol. It is not more ssluble in water than creosote. but mixes in all proportions -with alcohol, ether, )tlacta1 acetic acid, and alkaline leys. The sample I have is, however, of a brownish tinge, and is not ao soluble in alkaline solutions as guaiacol. A developer w»» made up as follows: — Creosol 1 c.c. Solution of caustic potash, 10 per cent 7 c.c. Water, to 30 c.c. The solution of the oil was not complete, a well-exposed plate took a long time to develop, but seemed to give fair density, which went off somewhat in fixing. With carbonates of soda and of lithia it only gave very weak images. It should be noted that, as in the case of guaiacol, the specimen of creosol I have used is not pure, and th« experiment should be repeated with the pure product, which is un- obtainable here. Ckeosote also has the PowEa of Development. Creosote from wood tar is a very complex mixture of phenoloid compounds, varying in character and quantity according to the method of distillation employed. In Thorpe's Dictionary of Applied Chemiitry, Mr. B. Nickels gives the following list : — Monokydric phenols : Phenol, paracresol, xylenol or phloral. Meihylic ethers of dihydric phenols ; Guaiacol, creosol, homocreosol, cojrulignol. Methylic ethers of trihydric phenols : Dimethyl -pyrogallate, di- raethyl-methyl-pyrogallate, dimethyl-propyl-pyrogallate, and methyl- pyrogallate. The principal constituents are, however, guaiacol and creosol, the former predominating in Rhenish beechwood creosote, while creosol forms the chief constituent of creosote from Stockholm tar. Of two samples of creosote, one " beech-tar " creosote of German origin and the other ordinary creosote, probably English, obtained from a local druggist, I find that both have the power of developing a gelatine dry plate when mixed with alkali ; but, while with the former the images obtained have been weak, those obtained with the latter show a good printing density, and are of a good brownish colour, free from stain or fog. The developer was made up as follows; — Creosote (English) 1 c.c. Solution of caustic potash, ten per cent 6 c.c. Water, to , 35 c.c. With ammonia the German creosote was only slightly soluble and developed a very weak image. The English creosote had quite a, different smell from the German, and more tarry. Both were only slightly yellowish in colour. It is difficult to ascertain what is the cause of the great diflferenc» in the developing powers of these two samples of creosote; but further investigation may lead to its discovery and the isolation of the sub- stance which produces it. In any case the developing powers of creosote seem to be worth further inquiry, though it is not likely to come into use as a developing agent in ordinary practice. Old Cabbolic Acid has Developing Powehs. I have also found that some very old carbolic acid (Calvert's No. 2) which has been kept here for some years, and become brown and oxidised, possesses distinctly marked developing powers when mixed with potash. The colourless crystals of unoxidis-ed carbolic acid of the same manufacture have almost no such power, though after pro- longed development in contact with the air a feeble image becomes visible. In this case tlie developing power is probably due to the formation of hydroquinone and pyrocatechin under the oxidising influence of the air. Electkolysis of the Developers. 1 have tried some of these developers by the electrolytic method, noticed in a recent paper on the amidol developer, published in the December number of the Journal of the Photographic Society of India, A solution of Guaiacol (colourless) .5 c.c. Caustic potash solution at 10 per cent .30 c.c. Water, to 120 c.c. WAS electrolysed in a voltameter with platinum electrodes about onie inch apart, using four gravity cells giving a current of 'IS amp^rs with a pressure of about 4-2 volts. .\t first the current through the voltameter was about 7 milliampores with a pressure of 1'3 volt, but it ran down steadily, and after thirty minutes was only 23 milli- ampores, with a pressure of 8 volt. Flydrogen was given off in a frothy form, at first fairly briskly, the yield being about -4 c.c. in five minutes, 'G c.c. in ten minutes, I'O c.c. in twenty minutes, and l"3c.c. in thirty minutes. The anode became coated with a brown resinous 200 THE BRITISH JOURNAL OF PHOIOGKAPHV, [March 31, 1893 substance, wliicli stopped the current. This substance was only par- tially soluble in alcohol -with a maroon-brown colour, and was very similar to a deposit formed by treating English creosote with baryta water. The same coating of the anode was noticed with silver electrodes, and the current was almost stopped, although the coating was very thin. The colour of the solution after electrolysis was a light maroon-brown with greenish reflections. The developing power of the solution was not found to be improved much by electrolysis, though the formation of the image seemed to be somewhat ac- celerated. A solution of the old discoloured guaiacol with carbonate of potash electrolysed under the same conditions gave similar results as to the yield of hydrogen, though the current through the voltameter at start- ing'was about 6'6 milliamperes with a pressure of 1'8 volt, and after forty minutes was4'25 milliamperes with a pressure of 1'4 volt, which is very much higher than in the first experiment. The yield of hydrogen was about '3 c.c. in five minutes, "6 in ten minutes, I'O in twenty minutes, and 1-9 in forty minutes. The solution, to start with, was a very dark green colour, which became paler in the hydrogen tube and still darker in the oxygen tube. The solution generally also darkened. The anode had a reddish-brown deposit upon it. The developing power of the solution after electrolysis was not tried till next day, and was found to have decreased considerably. Carbolic acid solutions electrolysed gave somewhat similar results as to the coating of the anode with resinous matter, and the conse- quent stoppage of the current. A solution of : — Old carbolic acid 8 c.c. Caustic potash solution, ten per cent 3^ » Water, to 120 „ was electrolysed with three dry cells giving a current of six amperes with a pressure of 3'7o volts. The evolution of hydrogen was very brisk, and some oxygen or other gas was given off at the anode. The yield of hydrogen was 1 c.c. in five minutes ; 1'9 c.c. in ten minutes ; 2'6 c.c. in twenty minutes, the yield of gas from the anode in the same time being '5 c.c. The current through the voltameter at starting was six milliamperes with a pressure of 3'7o volts, and in twenty minutes was six milliamperes with a pressure of I'C volts. The solution in the hydrogen tube became lighter in colour, while that in the oxygen tube darkened. The electrolysed solution seemed to have considerably increased developing powers, but this is uncertain, as it was tried under different conditions to the unelectrolysed solution. A similar trial of fresh carbolic acid and potash in the same pro- portions, using platinum electrodes and four gravity cells, was made. The current through the voltameter at starting was S'TS milliamperes, with a pressure of I'S volts. This pressure remained almost constant for thirty minutes, but at the end of that time the current was only 3".5 milliamperes. The yield of hydrogen was '5 c.c. in five minutes ; "9 c.c. in ten minutes ; 1'8 c.c. in twenty minutes ; 18 c.c. in thirty minutes, and -8 c.c. of gas was given off into the oxygen tube. The solution in the hydrogen tube remained colourless, that in the oxygen tube took a bluish dirty violet colour, and the solution generally had a turbid greenish tint. In a V voltameter with silver electrodes, the anode became coated at once with a brown varnish-like substance, and the current from six dry cells (about eight volts) barely passed through. The solution after electrolysis had no apparent developing power. I have not yet been able to complete these electrolytic observations, or to try creosote and creosol in that way. "With the exception, perhaps, of creosote, none of the substances experimented on appear likely to be of any practical use as developers, ' but I have thought that the fact of their having developing powers might be worth recording, and a further investigation of the sub- stances which cause impure samples of non-developing phenoloid compounds to exhibit developing powers may have useful results. Addendum. Since the above was written, the mail has just brought the Moniteur de la Photographie of December 1, containing Messrs. Lumiere's last paper, in which they show that guaiacol, after thorough purifi- cation, no longer reduces haloid salts of silver after exposure to light, and therefore is not a developer. They made a search for the sub- stance which communicates its developing power to guaiacol, but with- out the slightest success; the aramoniacal liquor in which tlie crude guaiacol was first washed develops an image, but all efforts to isolate and nnalyt'e the active agent failed, probably because it was only present in very minute proportions in the ammoniaeal liquid. Tliev remark that of some substances a very small quantity is sufficient to bring about the reduction of tilrer bromid". Forin«tancp, a photographic plate may be developed with an iilkiliiie soliitiun of para-amidophenol at one-ten-thousandth or less than two grains to a quart. As noted in my paper, my later experiments with guaiacol tend to confirm Messrs. Lumiere's conclusion that it is not a developer. Messrs. Lumiere do not seem to have observed with the pure product any trace of an image which could be attributed, as I have thought possible, to oxidation products. Consequently the faint images I have observed with my purer sample of guaiacol, and with clear crystals of carbolic acid, are probably due to oxidation products or other impurities present in my samples, and not generated during development. The question is a complicated one, and would require much closer investigation than I am able to give it. In connexion with the foregoing. Colonel Waterhouse has the following on the above subject in the Journal of the Photographic Hociety of India : — Guaiacol, Phloeol, and Ckksols. Since my last note, in the January number, was ^^■ritten I have tried two fresh samples of guaiacol, one of them purified from potash and the other an ordinary sample of English origin, obtained locally, which seems to be very pure, judging from its freedom from colour when mixed -with potash and the slowness with which it develops. Both these samples have, however, undoubted developing powers, and it seems diSicult to obtain a sample of perfect purity and without any developing power, unless one prepares it for oneself, 'as Messrs. Lumiere have done. It is an operation requiring more care and time than I can give it at present. I have also tried some other derivatives of creosote, among them cresol, para-cresol, and phlorol, and find that, mixed with potash, they are all capable of developing an image on a dry plate, though not practical developers. Phlorol seems the most active, but cresol develops without difficulty, while para-cresol only gave a very weak image in two days. The solution of the latter in caustic potash has a strong orange colour, which deepens by exposure to the air. It remains to be seen if this strongly coloured solution may be turned to useful account in conjunction with other developers. In this case also it is probable that the developing power may be due to impurities or oxidation products formed during the progress of development. As it seemed possible that the impurity which confers on these phenols the property of developing might be pyro-catechin, or some homologous substance, an experiment was tried to ascertain how small a quantity would suffice to bring ont an image. It was found that a solution of one-fifty-thousandth of pyro-catechin in a one per cent, solution of caustic potash (or about one grain of pyro-catechin in five pints of a five-grain solution of potash) was sufficient to develop a distinct but very weak image. It is possible that even a smaller quantity would suffice, and under these circumstances it may readily be understood how enormously difficult it is to obtain these complex derivatives of wood-tar and creosote absolutely pure and free from substances which have developing power. v, CoLONBL J. Watkbhous'e, I.S.C. ENLARGEMENTS PRINTED ON PREPARED CANVAS. In the "Answers to Correspondents,'' on page 9;"i, two alternative methods of making enlargements on prepared canvas are mentioned as being suitable because they give permanent results — "carbon transfers " and " dusting-on." Both are bichromate processes, and both, although the colouring materials are permanent enough for this purpose of being printed without the canvas being removed from the stretcher, and for painting upon in oil colours after having been printed, are about the most unsuitable that could be recommended. The carbon print must be made and developed on another (the flexible) support, and transferred to the oil-painted canvas, adopting suitable means to secure it thereon. I have tried to, and succeeded in, .squeegeeing the carbon tissue when printed direct on to the canvas, and developing it there, but it will be seen at once that the risk run of spoiling the prepared canvas by the hot water is so great that it is not a desirable way to work, nor would any artist of note risk the de- struction of his after-work on such a ground if he knew of it. The coloured gelatine of more or less thickness is also so antagonistic to the oil surface that, even when properly fixed, it is, so to speak, always struggling to remove itself. So opposite are the two bodies that a coating of gelatine, glue, or size, is used to prevent the preparation sink- ing into and spoiling the appearance of the back of the canvas, and this is sometimes done so maladroitly that pictures, especially if they are of considerable age and kept for a lengthened period in a damp place, will frequently scale off in large blisters as thick as egg-shells. This takes place where the sizing which the canvas generally undergoes is. MMch 31, 18!13] THE BlilTlSH JOURNAL OF PHOTOGRAiriY. ■Ml- 8S preTiously mentioned, too thickly coated or the sizing too strong. The sixe first swolls from the absorbed damp ; then, after a time, de- composes, piving forth vapours, and the paint and canvas part com- pany, entailing;, wliere the picture is a valuable one, no end of care, time, and trouble in putting a new canvas on the baclt of the old and rotted one, or otherwise removing the canvas, thread by thread and libre by fibre, from the scale of paint and picture, and cementing that down on a new canvas. Such a thing can bo done, l)ut never without injury to the picture. Where a gelatine film of appreciable thick- ness is interposed Ijetween the prepared ground and the oil colours ■which compose the picture — say, portrait — there the elements of de- struction are laid. I have seen such an example, even with a silver enlargement, whore gelatine in excess had been used ; the entire picture reticulated, so that, on looking through it in sunlight, it seemed as if pierced with a fine network just like a Meissenbach of transparent cracks, which they were. This was one of the pre- sent President of the Edinburgh Society's works, which he will remember, for he condenmed it at once as unfit to leave his establish- ment, asking my opinion of the probable cause of so unusual an appearance, and had another executed in its stead. Awell-known master, the late Norman Macbeth, U.S.A., a frequent contributor to these columns. Sir Georire Watson Gordon, P.K.S.A., as well as others who could be named, would never allow their cloths to be sized at all, but primed on the cloth direct, almost forcing the first coat through to attach the paint and canvas thoroughly together, just as plaster is forced through lathing and riveted, as they call it. So much for the association of the gelatino-carbon image with the oil- painted portrait enlargement. How this is, or may be, produced need not be noticed here. The dusting-on process is one that is based on a very different principle, the bichromatised colloid body being so treated that it becomes hygroscopic, and in printing from a negative a negative is the result, from a positive or transparency a positive. The print is produced by action of the humid atmosphere upon the insolated surface, and brushing over it a colour which sticks to the slightly tacky surface For this purpose very finely levigated black lead is probably the best. Gas black, or lamp black, also do well. Ivory black is recommended, but has not been so successful in my hands. There are also many of the other colours in powder which can be chosen if black is too strong in tint for the painter's scheme. The specifically lighter they are, the better will they take on the tacky surface of the colloid composition. One great objection to the working out of this process with any large size of plate and canvas is the difliculty in our climate and in most work places of keeping the air sufticiently dry and at an even equable temperature and degree of humidity during the process of brushing on the powder. Even in breathing upon it to confer the requisite degree of humidity, there is the great probability if the subject is large, say up to life size— of making one place more tacky than another, and so causing a heavy, blurred, smeary image, which no after-working seems able to clear This, which annoying in large subjects, is quite unfelt on small sizes,- where the aid of a friendly open fire assists in securing images fine enough for enamels, of which J have made several examples on opal glass as well as on the orthodox enamel plaque. The image, when finished from the enlargement, after washing, drying, &c., is too delicate to stand rough work with tlje painter's brush, and must be floated over with a coat of thin varnish, the thinner the better. All this trouble and care must betaken to produce an image which, in addition to its colloid nature, although that is hardened by exposure to light in conjunction with a bichromate, yet even that which is hardest, and also that which lias not been so affected, must retain, even when washed free of all surplus bichromate, and such sugar, or honey, or glycerine, or other hygroscopical addition, acted upon by acid, alum, &c., a most undesirable quality as an intermediary between two surfaces of oil paint, the canvas ground, and the artist's colours. The same remarks apply to another medium which is often used for cheap enlargements in o"il, " collodion transparencies " transferred to the canvas, and for that class of work they should be more strongly emphasised. Remains now the printing of the image on the prepared canvas ground itself, without an intermedia'ry, or only that with which the artist paints, Avhich will allow intermixture and penetration so that the material of which it is formed becomes one with the colours and the ground, and that is our old and safe friend, nitrate of silver, which, in spite of all that may be said as to permanency, is, in the method to be described, most permanent, one proof of which may be quoted. I was shown a short time ago by one of our best "artists one of several such prints on canvas that had been done by myself considei^ ably over twenty years ago, which had been knocking about the studio for all that time. It was a figure subject, copied from one of his own designs, on 26 x 1.5 stretcher, and there was no sign of change or fading whatever ; the whole thing was «o vigoroua that I wa.-* amaced it did not tempt the artist to begin and finish it, and said so; but he said, " I have already painted lialf a dozen of them, and am tired of it, even though 1 have been asked to finish it. I'll rather paint a new subject on the same canvas ; " and, on again calling at a later date, it had been painted out and was ready for the new subject. To begin with the prepared canvas itself : do not, as is the usual photographic habit, purchase the lowest priced, " made-in-Germany " kind of material at so many or so few pence each, or shillings a dozen, stretchers included, land of thing ; for, if that class of stuff is made use of for this purpose, it is almost certain to prove a failure. Rather use, although it costs more, that material made by such old- established London houses as Charles Roberson, Winsor «& Newton, Newman, Lechertier, Barbe, & Cie., and people of that stamp, who have a reputation to lose. If the buyer has a choice, take the oldest in stock. Prepared canvas is like collodion and wine — time ripens and improves it ; and, in selecting it, see that it is sound and some- what elastic, and without that habit, which some over-sized rolls have of cracking when handled, bent, or folded. Age also seems to abolish some of the bad habits of the newer or more youthful material, habits not suited to the best qualities of photographic printing, for which proceed as follows : — Take the strained canvas, wash it over with a cloth (flannel by preference) and water, using a little dry, washed whiting along with it to remove any surface impurity, finger marks, or grease, which often occur to sully the surface : wash clean with water, after this, and while the painted surface is still damp rub over and into it, with a small bit of cloth rather than a brush, or pad of cotton, a sponge kept for the purpose does well enough, the salting solution, which is made up of half a pint of tepid water, 40 grains of common salt, to which add 10 drops of acetic acid and 5 grains of previously melted gelatine. When this is dried, wliich can be done in front of a fire, take a 30 to 40 grain solution of ammonia nitrate of silver, the method of making which is, or should be, well known, and with a bit of Canton flannel, or a fine sponge does as well, having marked with a pencil round the negative or negatives, say of the head and hands, the position they are to occupy in the picture, those places only need to be salted and silvered, rub lightly over with the ammonia nitrate in all directions, and dry at once in front of an open fine. Go over the same places a second time, dry as before, and the canvas is ready for printing. It is well to have a toard the tliickness of the stretcher and slightly less than the inside size, to keep the canvas level, and, having arranged this wliere the canvas can lie flat, place the negatives in .their proper place with any little thing to weight them, on two sides only, there is need for nothing more in the way of pressure. The printing is very rapid, as silver printing goes, and may be fairly well judged by the colouration of the parts outside the negative or through the broad crosses, which should be scratched through the film to the glass. These also assist the registration when examining the print, which can easily be done by holding the qdge of the negative with one hand and raising it slightly with the other. When sufliciently printed, wash with water run on from the tap until the surplus free silver is removed ; do not tone, as there is no need for that, and fix with hyposulphite of soda poured on and kept in motion till fixation. This can be determined by the simple test of rubbing with the finger, when, if not fixed, the silver remains fast ; but, if .-ufticiently ."o, then the silver will rub off easily under tlie finger. All that remains is to run the tap for a few minutes, for, the surface being itnpervious, there is nothing to retain any trace of hypo, the infinitesimal quantity of gelatine not being able to retain any of tlie fixing salt. The finished proof may be dried either in the air or in front of the fire, and is then ready for the artist. I have said nothing of the placing of the figure in the proper place, or of the sketching in with a crayon the outline of the figure where the nega- tive is not made sufficiently large for this purpose, but will say a few words on the subject if that be needed. W. H. Daviks. PHOTOGEAPHIC liVDUSTEIES— JIESSRS. MOBGWUs" & KIDD'S WORKS AT BICHMOND. That the present popularity of the gelatino-bromide process for enlarge- ments is due to the efforts of Messrs. Morgan & Kidd, of Richmond, more perhaps than to those of any other firm, will bo easily recognised when it is understood that it is now some twelve or thirteen years since those gentlemen began to practise and exploit this system of photographic re- production. The artistic beauties and technical excellencies of the bromide work which they themselves turn out to such a great extent, con- joined to the admittedly high qualities of the now universally known bromide paper of their own preparation, entitle them not only to recogni- tion as among the earUest pioneers of the process, bat also to the thanks 202 THE BKITISH JOURNAL OF PHOTOGRAPHY. [March 31, 1893 tfhotogiaphers generally for having been the means of firmly establish- ing an enlarging method which, on ffisthetie grounds and on the score of Tjermanence of results, has long since achieved a most favourable place in ptiblic estimation. The growing use of gelatino-ohloride paper may possibly tell adversely on bromide paper for contact work in small sizes, but for enlargements we have yet to make the acquaintance of the process which will displace gelatino-bromide, or even challenge its pride of position. This reflection was forcibly borne in upon us on the occasion of a recent visit to Messrs. Morgan & Kidd's works at Bichmond, when we were favoured with the opportunity of making a rapid inspection of many of the departments in active operation. In what may be tei-med the exhibition gallery hang many charming bromide enlargements on paper and opal, both plain and coloured, which exhibit the capabilities of the process to perfection, while, before our departure we were shown some pictures over eight feet by four feet, intended for the Chicago Exhibition, and betraying a delicacy of gradation, wealth of detail, and harmony of effect such as one would expect to find in the very smallest work. Numerous rooms are set apart for making enlargements, and in one of these, Mr. Kidd, who kindly piloted us through the intricacies of these many-roomed works, allowed an assistant to make a 23 x 17 enlargement for US "while we waited," and the vignetting of the picture and the masking off of portions of it during exposure by the deft use of a large card with an aperture in it, was in itself a capital object- lasson in a valuable item of photographic practice. It was also interesting to observe how the picture was developed in a very ■shallow glass-bottomed dish with a quantity of solution which scarcely looked enough to cover a half-plate print, let alone one the size under treatment. Needless to say that the dish was not merely rocked, but kept in rapid motion from side to side, so as to ensure the even flow of the developer. Iron still reigns paramount at Eichmond, by the way. We notice that fixing of the prints is allowed to proceed in subdued light, that after washing they are well sponged down on an upright sheet of glass, and that they are cleared with acetic acid. For enlarging purposes daylight (with external reflectors) is used ; in dark weather and at night the electric light is available. A system of rapid contact printing, which we saw in progress, struck us as being very ingenious, and it will be of interest to the many thou- sands of readers of our Ai.junac, as the picture of the German Emperor given with the volume for 1892 was printed in this manner. The negative in a movable frame is fixed in an opening in the wall, behind which is a Welsbach light. The frame carrying the large sheet of bromide paper, upon which a number of exposures is mad'e, is placed in position, the negative by a simple movement brought into contact, the exposure given, then the negative thrown out of contact, the frame carry- ing the paper moved, the negative again brought into contact, and the sncceeding exposure given. At the time of our visit a large number of prints from one of Mr. Kidd's negatives of Durham Cathedral were being made. Each batch of bromide paper that is made is subjected to test exposures under a graduated screen, and a trial picture is taken bv exposure to a test negative having the widest range of tint. One room is set apart for the examination of the coated paper before packing ; another for a critical review of prints before they are sent out. We saw the operation of packing the paper in the now familiar tubes, the making of frames for the finished enlargements, gilding, moulding, &c. (here a department of considerable extent and importance in itself), and were permitted to have a view of the large staff of lady and gentlemen artists at work on bromide paper and opal and carbon pictures. Time did not allow of our making a detailed inspection of all the departments at Eichmond, but we were fortunate enough in passing a considerable portion of our stay in the, rooms devoted to the latest addition to their business which Messrs. Morgan & Kidd have made. This is the photo-mechanical and collotype department. Of the latter process a number of most charming specimens in various coloured inks, liang in an annexe of what we have called the Exhibition Gallery, which certainly take rank among the finest examples of this now favourite process of reproduction. In the collotype section, rooms are devoted to the coating, sensitising, and drying of the plates, the details of the process employed being given in a short paper by Messrs. Morgan & Kidd which we published a few weeks ago on the occasion of the demon- stration given to the members of the Eichmond Camera Club. Both hand and steam power are employed for the printing, the former for very small work. The collotype machines used are those of Messrs. Schmeirs, of Leipzig, and work up to the largest sizes ordinarily available. Ex- amples of Messrs. Morgan & Kidd's collotype work appear in the Yachts- man, Kiimeledge, and other publications ; and while we were at Bichmond we were shown, among other specimens, reproductions of corals for a work on the subject being prepared under the superintendence of Dr. Gunther, of the British Museum. Our last Almanac, as our readers know, also contains an example of the process, which has been highly eulogised. As occasion requires the electric light is availed of for enlarging and illuminating purposes throughout the establishment. The non -actinic light employed in the enlarging rooms is of a most agreeable nature, oiled orange paper screening the lamps. Some of the developing trays in occasional use are of such enormous size that they can only be actuated on a species of ball-and-socket arrangement placed on the floor to support them. The ordinary water used at the works is drawn direct from the adjacent Thames, and passes through a huge carbon filtering apparatus much resembling a gasometer on legs. Asked how much paper was coated per diem, Mr. Kidd, in preference to committing himself to any arithmetical statement, smilingly said that the daily quantity would last almost any photographer a lifetime. The premises cover a large area of ground, including, as they do, departments, in addition to those mentioned, for carbon printing, the coating and drying of the bromide paper, plate-making, &c. The number of rooms occupied defied our own attempts at counting, and Mr. Kidd's memory. But we did learn that the firm employs over a hundred persons (with the precise number of which, in contradistinction to the rooms, Mr. Kidd humorously said every Saturday made him acquainted), and in concluding these brief notes of a highly interesting visit we cannot more fitly do so than with congratulations to employers and employes at the good and cordial inter-relations which we did not fail to observe exist at Messrs. Morgan & Kidd's works at Eichmond. VARIOUS METHODS OF ADDING CLOUDS TO L.lNDSCAl'ES. These has been so much said and written on this subject that one might think tliat everybody knew everything about it, and that the reiteration of the oft-told tale was but so mucli wasted time and paper. Notwithstanding this, a large percentage of those wlio practise photography for amusement consider it either a too trouble- some a process to adopt, or do not feel themselves sufficiently expert to risk spoiling a print that is good in all other respects by an addition of which they feel somewhat doubtful of properly performing. I am induced to make these remarks having occasionally met most painstaking and apt amateurs who would not hesitate to spend money and trouble over their hobby, and yet who make their prints with quite blanli skies, or not more than .ilightly tinted, just sufficient to tone down the glaring whiteness of the paper. This, then, is my excuse for recapitulating the well-worn topic of liow to put clouds to landscapes. The methods of performing this really simple process are somewhat varied, and most of them capable of producing satis- factory work when properly handled. The busy photographer will undoubtedly give the preference to that plan which is most easy to do and gives a minimum of waste. In the first place, a few words about taking a cloud negative will not be out of place. We must not start with the idea of a cloud negative being neces- sarily that which will print an excellent study bi/ itself, as many excellent pictures, from this point of view, are utterly unsuitable for adding to landscapes. The most useful in this connexion would probably make very poor, flat pictures by ttiemselves. Imjirimis, find your clouds by selecting some elevated or other position wbere there are no obstacles in the foreground or middle distance to inter- fere with a clear and unobstructed view of the horizon. The effect of perspective must be considered in clouds as much as in land- scapes, and those taken with a level camera are generally the best and most effective. A little tipping of the instrument is of no conse- quence; but clouds, like the earth beneath tliera, are subject to the same laws of perspective, although these laws may be violated with less chance of attracting attention. It is preferable to set about copying them on a right principle. The seaside offers the very best opportunities for good cloud studies, hut it will he observed clouds formed over the sea are somewhat different in character to those over the land, especially as they ap- proach the horizon. The photographer should have both kinds at hand. With regard to the position, one looking west affords most opportunity for effect, especially if we are desirous of moonlight or sunset effects. Of course, clouds may be found at all points of the compass, and those formed in the north-ea,-t or south-east are often very Ijeautiful. A morning suiiri.se is not so good for our purpose as an evening sunset, owing to a greater proportion of vapour and haze than later on in the day, it being almost impossible to get sufficient March 31, 1893] THE BRITISH JOURNAL OF PHOTOGRAPHY. 303 contrast in clouds if any haziness intervenes, a very little destroying the delicate nuances of shading that add so much to the cloud beauty. This fact makes cloud photography in towns diflicult, for there is generally enough smoke to obliterate all clouds for some degrees above tlie horizon, if nothing else interferes in the form of chimneys and buildings. Clouds on the zenith are absolutely useless for any photographic purpose, always looking manpy and out of perspective when added to a landscape. This difficulty, no doubt, deters many from trying to make cloud negatives. Patience and opportunity are undoubtedly required, and a little disappointment must not be minded. Generally siwaking, stormy weather provides the greatest variety of forms, and quiet after the storm is usually best of all. Very tine cumulus clouds may be secured in settled summer weather, but the spring months generally aiford opportunities for cloud work that should not bo neglected. Some think a mackerel sky good for printing in ; but, as this pattern of cloud depends for its effectiveness on tlie contrast of pearly white with deep blue, it is somewhat disappointing in the negative. Of all patterns of clouds, a rather dark one, with a bright edge, is most useful for combination printing, especially if there is only a small space to till. Our station being selected, its aspect carefully noted, there is no alternative but to wait for the clouds to arrange themselves to suit the fancy of the photographer. A finder in the camera is very useful. Unfortunately, a day when the most effective grouping occurs is often objectionable on account of wind or showers, and the elevated position selected adds to the discomfort. Bearing this in mind, a light, llimsy outfit is less suitable than a heavier and more substantial one. A good waterproof cover for the apparatus will often come in useful. It sometimes happens that the shutter of the dark slide has to remain open for some time longer than ordinary in order to make the exposure at exactly the right time. Extra precaution must be taken to prevent access of 'light to the plate in the interim. A cord tied to the camera screw, and pulled down firmly to the ground immediately beneath by means of a peg, a stone, or a loop in which the foot can be placed, will add considerably to the rigidity. Any good, clear-working plate can be satisfactorily used, and should be backed. Excessive rapidity is a drawback. A plate such as the Ilford ordinary is quick enough with an exposure of half a second, and with a stop about /-64 for the time. No part of the limb of the sun should be visible in the negative if the clouds passing the sun %te to be taken, or a dense patch of light will result, quite spoiling the effect. The quality of negative required is a clear, thin one, showing good contrasts, and plenty of detail, with little density. The exposure and development must be calculated for this effect. Any lens giving a flat field and good definition is suitable. "Very rapid exposures are not required, as a rule, although now and again an instantaneous one may be necessarv ; but better results for our purpose are obtained by longer exposures, the development being calculated accordingly. There are so many opportunities of taking clouds when they are nearly motionless, that such times should be selected for taking them. Owing to their distance, a slight movement in the masses of vapour is not noticeable on the negative with the short exposure required. As to development, any of the usual kinds will answer. Such combination that would be used to render white drapery will make good clouds. Ilydroquinone answers very well, but most of mine I have developed with pyro-ammonia well restrained. I would suggest that the kind of development to which the photoffriipher is most used is best. Knowing what he wants, he sets about getting it as with any other sort of negative, and as far as I know there is no particular treatment required. A clear, thin negative is to be tried for, so thin that the prints over which it may be laid are distinguishable through all biit the very densest portions. In a good diffused light (direct sunshine must always be avoided) a cloud negative should be suffici- ently printed in ten minutes or less. The effect of using a too dense negative is to get a patchy effect, the dark clouds coming too dark for the landscape, and the light ones deficient in detail. If the printing is continued to get out detail, the whole thing will look heavy and bad, and the picture will lack atmosphere and become worthless ; on the other hand, a clear, thin negative will enhance the atmospheric effect. One great difficulty in using unsuitable cloud negatives is to so mask the picture that the junction between the two is unobservable. It is almost imp^iblo to do this without either letting the clouds encroach on the distmce of the landscape and get muddled up with it, or show a clear wliite space between the two, either of which is fatal to artistic effect. If the printing is properly managed with suitable negatives, I if even two or three are used, the closa»t scrutiny should fail to discover the junction of them with the landscape, or any signs of double I printing whatever. Edward Di'nmoek. {To be coHcliuh'd.) ON THE APPLICATION OF PHOTOGBAPHT TO SEISMOLOaY AND VOLCANIC PHENOMENA. Tbxbe is scarcely a branch of art or science that does not at the present day call in the aid of photography, either directly or indirectly, and seismology is no exception. It may, therefore, not be out of place, in the case of a journal particularly devoted to this subject, to enumerate and briefly describe the various applications of photography that have actually been made, or that ore suggested, in connexion with earthquake and volcanic phenomena. Effects ok Eabthqcakks. First, of course, we have the common application of photography to record the effects of earthquakes and of volcanic eruptions. The value of photographs of this kind cannot be over-estimated, but it will not be fully appreciated till considerable time has elapsed, and until future seismologists want to compare the effects of earthquakes and eruptions of their time with those of the present time. We can imagine of what value they will become if we think what we would give for an accurate set of photographs of the effects of any historical earthquake or eruption, say, of the last century. Undoubtedly, a hundred or two years hence, it will be of the greatest importance to geologists to be able to compare the condition, for example, of Bandai-san with its condition within a few days of the eruption that blew its upper half into the air nearly five years ago. The more rapid changes in the interior of the craters of active volcanoes can also thus be noted with advantage. Even such secular movements as the gradual rising or depressing of coasts may also, perhaps, be recorded more definitely than they have been heretofore. There is one thing that should be emphasised here, and that is the importance of preserving systematically all photographs of the kind mentioned, printed by some permanent process. In cases where the photograph is of such general interest that the outside public may be looked upon for the purchase of anything over about fifty copies, the collotype process is, at the time of writing, to be recommended ; in other cases the platinotype, in spite of its present comparative expensiveness, on account of the recent great rise in tlie price of platinum. Up to the present time, so far as the writer knows, such photographs as are of particular seismic interest are to be found scattered through various publications, but have not been systematically brought together in any single collection. CCBVATCBE OF THE SIDES OF VoLCAHOKS. Professor John Milue has used photography in determining the curvature of the sides of volcanoes. That is to say, the inclination and curvature were measured from photographs at the time in existence. In using photographs for this purpose it is necessary to be sure that the swing back of the camera was vertical at the time the photograph was taken, otherwise the measurements will not accord with the truth. Now, although photo- graphers have been pretty well drilled into appreciating the necessity of having the swing back of the camera vertical in the case of buildings, there are few that appreciate the necessity is oases where the subject contains no right lines, and the greater number of photographers " tip " the camera without bringing the swing back to the vertical again in photographing a high mountain. This is, indeed, one of the reasons for the commonly unsatisfactory rendering of mountains by photography. The effect of tipping back the camera without readjusting the swing back is to give an effect in the photograph as if the mountain were leaning away from the camera to just the amount that the f^roimd glass leans back. In other words, the slope of the mountain is reduced, and the mountain is dwarfed. There may also be slight errors due to refraction. Copying Seismogbaphic Records. We next come to another set of uses of photography that need little more than enumeration. Thus the record of an earthquake, by nearly every seismograph, is scratched on smoked glass, the smoke film being afterwards fixed with common photographic varnish. It goes without saying that photography is the best way of obtaining copies of such records. The blue process is most commonly used, although, in the case of the small diagrams given by bracket and duplex pendulum seismo- graphs, more delicate processes have a decided advantage. Except for want of permanency, albnmeniscd paper is to be preferred to anything, else. It scarcely needs to be stated that photography has been useful in pro- ducing illustrations of seismological instruments, also, in a number of matters of detail such, for example, as the production of scales, with.finei division than any that were readily procurable machine divided. Pbofessob W. E. BintTOS. (To be eontinued.) 204 THE BRITISH JOURNAL OF PHOTOGRAPHY. [March 31, 1893 LEICESTER AND LEICESTEBSHrRE PHOTOGRAPHIC SOCIETY'S EXHIBITION. The second public exhibition of photographs by members and others of the above Society was opened on the 22nd inst. by the Mayor of Leicester (Alderman Underwood), in the Co-operative Hall, the latter a handsome apartment, no doubt admirably adapted for functions of a poUtical or theological tendency, but leaving much to be desired when the object in view is to display to the beat advantage a collection of pictures. How- ever, arrived at length, mentally recalling a couplet well known on the Tyne-side— " Stairs, stairs. Who climbs them, swears!" at the locale selected, we are able to chronicle a distinct success for the Leicester Society, and to congratulate them on a small but very creditable and interesting exhibition. Some sixteen members sent in frames, and others were contributed by workers in various parts of the county. Dealing first with the work of the members, it is clear that the chief honours fall easily to the President (Mr. Porritt) and Mr. G. Bankart, both in reference to the artistic selection of the subject and careful, tasteful, technical handling of the negative. Mr. Porritt shows various enlargements, all excellent and pleasing, Old Cottages at Knighton, perhaps, taking the palm. The President's smaller work is also very good — No. 7, Roman Bridge, a difficult subject well rendered ; No. 17, lioman Baths ; and some charming studies in Derby and Wales, all worthy of particular notice. Mr. Bankai't's work is so well known and so good as hardly to call for further criticism. He contributes eighteen views — carbon prints — all, with one exception, rather cold in tone. It is a' question whether a rigid adherence to one tone, say, engraving black or Indian ink, is desirable; we tliink not, and fancy that several of these fine pictures, notably the pure landscapes, would have looked better in sepia or brown. Mr. Bankart's carbon prints are, in quality and finish, up to anythingwe have seen in this beautiful process. Mr. Frank Brown ghows several enlargements, all in his best style. Mr. F. G. Pierpoint also contributes three enlargements, all showing a considerable amount of work, but effective and pleasing, Haddon Hall making a striking picture. Mr.Pickering (the Hon. Secretary) is represented by a few architectural studies, all of good quality. Messrs. Seville & Co. exhibit, with other work, a very good enlargement in bromide, Now for a Sail— Yarmouth Beach, a familar and artistic sabjeet. Mr. J. H. Seddon shows promise of better things to come in Views in and around Knighton. Other exhibits by members are contributed. Messrs. S. P. Baker, Cowdell, Robt. Frost, F. JoUiiJe, S. S. Partridge, J. Toone (whose landscape work is the better), G. E. Woodcock, and A. W. Wilson. Mr. T. Scotton also proved a tower of strength to the home side by his collection of fine enlargements and architectural subjects, Lincoln and Peterbo/viigli Cathedrals being particularly deserving of praise. The exhibits loaned, and most of them shown at other exhibitions, comprise work by Bernard Alfieri — The drey Baton, SnTViCt, Against the Shy, &c. ; examples by Mr. S. Francis Clarke; some half dozen charming studies by Mrs. Clarke ; medal pictures by A. R. Dresser ; studies and enlargements by the Autotype Company and G. W. Wilson ACo., the latter's exhibit including also work byF. M. Sutcliffe, the ever-welcome Jl'ater Hats and A Stem Reality ; and Chas. Reid. Mr. J. Pike, of Leicester, sends six frames ; Mr. Martin J. Harding, of Shrewsbuiy, some fine " bits " and snap-shot pictures, these latter very good indeed ; Mr. Isaac Slater, of Llandudno, six landscapes, which for detail, selection and perfect tone are very hard to beat ; and Mr. R. Keene, of Derby, a series of his well-known views. Lantern slides by the President (Mr. Bankart), Mr. Wilson, Mr. Pickering, and others, were shown on the screen at intervals during the evenings ; vocal and instrumental music also diversifying the proceedings. It should be mentioned that the Hon. Secretary (Mr. Pickering), immediately after the opening ceremony, became the happy recipient, at the hands of the Mayor, on behalf of the members, of an optical lantern by Archer & Co. ; this lantern was used for the projections, and is evi- dently a very fine instrument. It only remains to be said that the ex- hibits were well arranged, that a neat little catalogue was issued, and that the public attendance was everything to be desired. Opiimus Spihit-level. Messrs. Pkbkbn, Son, & Rayment are intrcdHcinp; a small spirit- level for attaching to the side of tlie camera, and capable of being ©ur IBlJitorial 3ratle. Stereogbaphs. By HOBATIO N. KiHG. Mr. King has sent us some choice stereographs, both ancient and modern. Those of the former class are views on paper of the Bum- ham Beeches, from collodion negatives, taken by him, in company of the late Frederick Scott Archer, over forty years since. The nega- tives from which these were printed must be in a state of (rood preservation, showing, as they do, no evidence of having faded. The others are transparencies on glass, forming views respectively in Windsor Castle, Haddon Hall, and Hampton Court Palace. These are backed by a matt varnish having an exceedingly fine grain. used either laterally or horizontally, as indicated in the cut, the level itself folding back to the side of the camera, and being observable when in that position. It should prove a useful little adjunct. RECENT PATENTS. PATENTS COMPLETED. iMrliOVEMENTS IX THE il.VNUFACTCRK OK PvKOXVLIXE SOLUTIONS AND COMrOUNDS KOR VakNISHES AND COATINGS. (Communicated by Frederick Crane, Bloomfleld, New Jersej', United States of America.) No. 6542. Joseph Sixclaib Faihkax, 433, Strand, London. February 18, 1893. This invention, as communicated to me by my foreign correspondent, relates to improvements in the manufacture of pjToxyline solutions and compounds thereof for various useful purposes ; and it refers to solutions and compounds of a similar nature to those employed in my application No. 6543 of even date lierewith. The pyroxyline, or nitro-cellulose, used in the manufacture of these com- 1 lounds is of the kind or grade known as soluble pyroxylinc, and is obtained ijy suly'ecting vegetable fibre to the action of nitric acid, or of nitric and sulphuric acids, in a manner well known. The solutions and compounds referred to are in a liquid, or senii-liquid, con- dition at the time of their use or application as varnishes or coatings, and which eventually become set and hard. The invention consists in the employ- ment of certain known tiuids wliich have been discovered to possess tlie pro- perty of dissolving pyroxyline at ordinary temperatures, and whicli also impart to the pyroxyline solution or compound made by tlieir aid certain peculiar and desirable jiroperties. For many purposes for which pyroxyline compounds are used, and particularly where sucli compounds are used iii the form of thin solutions for hicquei's or varnishes — or in the form of lieavier solutions to be evaporated down to a solid film — it has been foimd especially desirable to use a solvent for the pyroxyline which would volatilise with con- siderable rapidity, and at the same time would not absorb water or moisture from tlie atmospliere to any aiipreciable extent. So far as hitherto known, no one solvent for pyroxyline combined both these properties of quiclc dryiii" aud non-atlinity for water, and it has been customary to use a compound solvent therefor. By this is meant a solvent consisting of several distinct substances artiticially united for tlie purjiose of proilucing the kind of solvent required, and this compound solvent would consist — in p,art at least — of liquids having an allinity for water ; as, for example, methyl alcohol and acetone. The com- pound solvent would also partly consist of non-hygroscopic liquids (not having an affinity for water), such as amyl acetate and benzine, the two classes of solvents being mingled in such proportions as would be necessary- — in each case — to produce a solvent suflflciently non-hygroscopic for the use for which the pyroxyline compound was required. ^ Now, it has been discovered, and communicated to me by my foreign corre- spondent, that the substance commonly known to the trade as acetone oil, when purified as hereinafter mentioned, is not only a powerful solvent of pyroxyline, but dries with considerable rapidity : tliat it is practically non- liygroscopic, and can be used either .alone or in combination with some miscible and cheaper liquid (such .as ben/ine) as a solvent for pyroxyline in all pjToxyline compounds where heretofore it has been necessary to use compound solvents. March 31, 1893] THE BRITISH JOUKNAL OF PHOTOGUAl'HV. 206 This acet'Uio oil is coiiii>ose(l niainly of wliat are known us volatile ketones, lioilinK IhIow 140° C. Those ketones may be obtained by the destructive ilis- tillation o:' inctiilliu acetates. While a clieinically pure and dry acetate aliould viilil a I'Urc acetone with simultaneous forniutiou of the corresponding car- liouatt^-. tlio crude or coniiuercial acetate will yield a distilljite containing in udditi"ii to acetone and water these higher ketones along with certain acetates and otlur dcfoniiiositiou pnxlucts. Tlie : •etonc :ind water liavinp l>een eliminated by the usual procenses of fractionatifin :ind absorption witli deliydrating agents, tliere remains an oil, which my foreign coiTe«iioudent informs me has valuable projierties. Kor some uses, liowever, it is not necessary to remove the acetone, for it is a solvent of pyroxyline, and, where a non-hygroscopic liquid is not required, it is not ii!] lions to tlic comixiuml, even if present in considerable proportions, while, it .. j.vactically non-hygroscopic solvent is desired, a small proportion of acctiini' is rcndoicd innoxious by the pre.roceed to specify some of the mixtui-s aud uses to which the same may be apiplied. For pyroxyline compouuiU to be used as Lacquers or varnishes where it is essential that tlie film or < oating remauiing after the solvent has evaporated should be adhesive, tough. l:aril, smooth, free from cloudine-ss, and especially where quick-drying gallons methyl alcohol or acetone. 5e plate from the respective bath, holds the same under a rose, while the carriage automatically opens a cock by which water is supplied from a resen'oir to flow over the plate ; the plate is then transfen-ed to the next carrier and immersed in the next bath. When any person desires to be photographed, that person stands in front of the machine ami draws out a handle, which carries back the carriage to its commencing position, lifting the c.iver from in front of the dark chamter, ami so exjiosing a sensitive plate in the camera by a lever action operated by the carriage. On dropping the requisite coin into the slot, the lens is uncovered, and at the proper time again covered. The carriage, having been as aforesaid drawn back by hand, on 'release of the han.Ue moves gradually forward under influence of a Weight, and imder control of a .suitable speed governor, so thit the ejtposed plate, dropping into the first carrier, is dipped in the first bath, and undergoes the successive operations necessary for proerate when the handle is again drawn out. In connexion with this apparat\is I employ an electric incandescent light, of sufficient power for illumination of the person photographed just at the time of exposure, causing tlie mechanism to close and inteiTiipt the circuit exactly at the correct moments, so that the electric supply may not be wasteil. I also employ a snudl continuous electric light upon the machine ■ufficient to enable tint instructions, 4c., to be read. A further improvement consiitts in on electric beatina device to dry the photographic plates previous to delivery. This device u abo internuttent, being supplied with current at the time only at which the plate to be drieil is passing adjacent to it. It consists of a fabric of wire warp— for instance, cop]ier, platinum, or other convenient metal — to be heated by passage of the current, and a weft of asbestos fibre. iMPBOVBJIKXTS IN PHOTfH;RAPHIC C'AMBRA-S. No. 6744. Waltkk Palmer, Westfield, Tteoiling, Berks.— /Wruory 25, 1893. M v invention relates more especially to the photographic cstmeras known as " hand " cameras, and has for its object to reduce the size of the camera and to enable the focussing to be very rapidly effected. According to my invention I employ a frame or part known as the front of the camera (to which is attached the lens and shutter of the camera), a central frame or jiart, and a frame or part known as the back of the camera (which is aiTanged for the holding of the negative picture). Tliese frames or parts may be of any convenient shape. They are connected t(^ether from iioints within or without their sides by a system of lazy tongs, which may be applied to either two or more sides of the camera. The lazy tongs start from one point of attachment on any one side of the back or front, crossing the central frame in one point within or without that side, and ending in one point on the corresponding part of the front or back. The systems of lazy tongs are in planes either parallel or at right or other angles to each other, and the centres or points of attachment on which the parts work are fixed on the front central frame and back respectively, thus ensuring a rigid and parallel backward and forward movement of the front and back, the central frame being at the same time maintained at the projier distance between the front and back, no matter what may be the amount of expansion of the lazy tongs. The movement of the lazy tongs also enables me to arrange a convenient focus indicator. Within or without or both within and without the lazy tongs is a non- actinic casing or covering, capable of expsmding or contracting with the movement of the front and back. Mnting^ of Societtesi* MEETINGS OP SOCIETIES FOR NEXT WEEK. I>ate of Mooting. Name of Society. April 4 Birmingham Photo. Society ... ,, 4 Beaton Photo. Society „ 4 Brixton aud Glapham ,, 4 Bxeter .-. „ 4 Hackney „ 4 Herefordshire „ 4 Lewes „ 4 North Loudon „ 4 Oxford Photo. Society ,1 4 Paisley „ 4 Rotberham „ 4 1 ShetBeld Photo. Society „ 4 1 York „ S Edinburgh Photo. Society „ 5 ' Leytonstone" , „ 5 1 Photog^raphic Olnb „ 5 1 Southport „ 5 j Southsea „ 5 1 Wallasey „ 6 \ Binuingham Photo. Society ... „ 6 1 Camera Clnb..-. „ 6 j Dundee and East of Scotland ... ,, € Glasgow Photo. Association „ 6 Glossop Dale Hidl. Place of Meeting. Clob Boom, Colonnade HoteL 10, Bnshton-street, Bolton. 376, Goldharboar-lane, Brixtou. City Chambers, Gandy-st., Exeter. 206, Mare-street, Hackney. Mansion House, Hereford. Fitzroy Library, Hi^h-at., Lewes. Canonhm-v Tower, Islinftton, N. Society'3 Booms, 136, High-street. 9, Ganze-strect, Paisley. S, Prederick-street, Rotherham. Masonic Hall, Surrey-street. Victoria Hall, Goodramgate, York. 3S, Ca.stle-street, Edinburgh. The Assembly Room;', High-roacL Anderton's Hotel, Fleet-8treet,B.C. The Studio, IS, Cambridge-arcade, o, King's-road, Southsea. Egremont Institute, Egremont. Club Boom, Colonnade Hotel. Charing Cross-road, W.C. Lamb's Hotel, Dundee. Philoso. Soc. Rooms, 207, Bath-et. 71, Prospect-street, Hidl. Meclmuics' Institute, Leeds. „ 6 ' Leeds Photo. Society - „ 6 ' London and Provincial ' Champion Hotel, 15, Aldersgate-at. „ 6 1 Oldham The Lyceum, Union-Htreet.Oldham. „ 6 Tunbridge Wells I Mechanics' Inst., Tnnbridge Wells. „ 7 1 Cardiff „ 7 1 Croydon Microscopical PnblicHall.George-street.Croydon. „ 7 Holboi-n „ 7 j Leamington Trinity Church Boom, Morton-st. „ 7 1 Maidstone "The Palace," Maidstone. „ 8 1 HiiU.„ I 71, Prospect-street, HoU. LONDON AND PROVINCIAL PHOTOGRAPHIC ASSOCIATION. March 23, — Mr. .K. Haddon in the chair. Angle ok View. Mr. Hadikix (having temporarily vacated the cliair for the pnrpo.se) soul that Mr. Everitt stated that some ye.ars b.ack the late J. H. Dallmeyer, in a pamphlet, had given exactly the same rule for calculating the angle of \-iew included on a plate as he (Mr. Haddon) had done in his Almanac article. He (Mr. Haddon) would like to say that he was ignorant of that fact. Criticising Mr. Everitt's remark that artists sometimes placed the point of sight outside the picture itself, and the same gentleman's nile for finding the angle included bv measuring the distance from the iioint of sight to the furthest point of the plate, Mr. Haddon asked, " If the rule were carrieii to an extreme, and applied to only a small part of the picture, would it be right to say that, in the latter case, the angle included was as great as in that of the former !" 206 THE BRITISH JOURNAL OF PHOTOGRAPHY. [March 31, 1803 Mr. P. EvKRiTT, in ciuotingMr. Haddon's rule, said its mistake was in tak in tlie long' side of the plate instead of the diagonal, and quoted Professor W. K Burton and Dr. Eder as supporting his (Mr. Everitt's) views. ^ ^ . , It was understood that the subject would he further discussed at a future meeting. The Association's Technical Lectures.— II. Cameras, Dark Slides, AND Tripods. Mr. Edgar Cui-ton delivered the second of the series of technical lectures already announced. In it he showed the development of cameras in use at the present time, describing the simple form of box camera used by Nii-pce m 1818 ; the collapsible camera ; the telescopic camera of metal, suggested by Grubb, .and which Mr. Clifton was of opinion might be serviceable for large sizes now. The first bellows-body cameras were made on the concertina principle. Having shown that the Kinnear camera, introduced in 1853, had been perpetuated in the conical-bellows cameras now in present use, Mr. Clifton e-xhibited a modern camera of that form, also one of square form, and dilated upon their respective advantages and disadvantages from a pr.actical point of view. Latimer Clark's stereoscopic camera was shown and described, and the lecture concluded with an examination of dark slides, ancient and modem, as well as the various types of tripods. A discussion followed, the lecturer being thanked. The lectures, with the discussions upon them, will he ultimately published in book form, hence the brevity of our report. Affiliation of Fhotograpliic Societies. — Meeting of Delegates, March 24, Mr. Edgar Clifton (Photographic Club) in the chair.— The Secretary announced that, since the last meeting of delegates, seventeen more societies had been admitted, bringing the total to forty-six in all. The sub-committee which had carried out the technical lectures on photogravure presented their report, in which they expressed an opinion that their success yields great encouragement towards undertaking something on similar lines in the future, and that they were very greatly indebted to Mr. Herbert Denison, and to Mr. Horace Wil- mer, for their assistance. On the proposal of Mr. F. A. Bridge (Photogi-aphic Club), seconded by Mr. Beckett (Hackney Photographic Society), the report was adopted. 'The Chairman said that, owing to the lamented death of Mr. William Bedford, it would be necessary to appoint a fresh chairman, and on the proposal of Mr. P. Everitt (London and Provincial Photographic Associa- tion), seconded by Mr. A. Mackie (Photographic Society of Great Britain), Mr. Andrew Priugle was unanimously appointed. Mr. Everitt remarked tliat, up to the present, they had not received a balance-sheet, and he was of opinion that a regular date should be fixed upon which the annual balance-sheet should be presented, and he would propose that the Treasurer be requested to funiish a balance-sheet to date, and that such balance-sheet be presented at the next meeting of delegates. After some discussion it was seconded by Mr. Mackie and carried. The appointment of an independent Treasurer was raised, but at the suggestion of Mr. Bridge this was deferred until the balance-sheet should be in the hands of the delegates. The question of the organization of the 'Technical Albums was raised, and the Secretary was instructed to communicate again with the Secretaries of the Societies in the matter. A lengthy discussion ensued on the advisability of the AlHliation inviting a conference of Judges to consider exhibition rules, and it was finally decided that this should be done, and a sub-committee was appointed to arrange preliminaries, the sub- committee to consist of Mr. Beckett and Mr. Mackie, together with the Chair- man, Mr. Andrew Pringle, with power to add to their number. City and Guilds of London Institute. — March 22. — A paper was read by Mr. Stayxes on PinJwle Photoi/raphy. A special prize is being offered by Mr. Staynes for this class of work at the forthcoming competition of the Society. North London Pbotographic Society.— March 21, Mr. Oakley in the chair. — A Special Lantern entertainment was given in the reailing-room at Canonbury "Tower, when there was a large attendance of the members of the Canonbury Constitutional Club as visitors. About 300 slides were shown, which, with few exceptions, were of excellent quality. A selection from the Leeds set was also shown, and some slides kindly lent by Messrs. H. M. Hastings and Guardia were much admired. The next meeting will be on April 11 instead of Easter Tuesday. Harrlngay FhotograpMc Society. — March 24. — A Lantei-n Lecture, entitled The Thaincs from Sunrce to Sea, was given by the President of the Society (Mr. Dudley Towers), and a collection was taken for the liquidation of the debt on Emmanuel Church. Hackney Photographic Society. — March 21, 1893, Mr. R. Beckett pre- siding.— Question: "Can any member give his experience of the Zokahand camera?" Reply :" Good, as a low-priced camera. ' Question: "What lens is best for landscape work ? " Reply : " Rapid rectilinear, or single landscape, if it will work at/-ll." Mr. R. Beckett recommended having a lens tliat will cover a size larger than the plate, so that it will cover when the lens is raised. Mr. S. Herbert Fey then gave his demonstration of the Sandell plate. A e process is not patented. The patent for the Woodburytype process has expired. J. C. W.- — If you have not registered the copyright, there is no redress. Treatment such as you detail is by no means unusual by the illustrated ptipere. A. White.— Send a sketch or rough plan of the proposed studio and the surrounding buildings. On the other matter, refer to tlie local regulations as to buildings. S. W. — A lens with an an aperture otf-6 will do admirably for a hand camera, but we doubt whether any lens of this aperture, of four-inch focus, will cover with line definition to the edge of a quarter-plate. H. Thorne.— Quite true. It is illegal to copy a bank note by photography or any other means, even if tlie size be difterent from that of the original. Probably, if the size was an inch or so less, no notice would be taken ; still the illegality is the same. W. WiLioncHBY.— Burton's work on Photo-mechanical Printing, published ■ by Messrs. Marion, Soho-square, deals fully with collotype. Numerous articles on the subject have also from time to time appeared in tliis Journal, which siioukl be of assistance to you. SOBA. — 1. See reply to H. Mace. 2. In the same way as .albumen prints are burnished if they are made perfectly dry. 3. Not if you can get practical lessons from a competent teacher. 4. It depends upon the result required. The majority of sitters are not satisfied with prints Irom negatives that have not been retouched. H. Mace.— Without knowing the form of the studio, it is difficult to advise as to the area of glass that should be employed ; but, if it be of the usual ridge roof form of the dimensions stated, then the glass, starting, say, foui feet six inches from tlie background end, may extend for ten or eleven feet at the side and top. If you send us a sketch of the studio, we shall be able to advise you more definitely. Studios.— Several correspondents have written of late, asking advice as to glazing studios— the amount of glass, its position, &c. If these communica- tions had been accompanied by a rough sketcli of the .structure, and its aspect, we should Lave been en,abled to advise more definitely. The amount of glass in a studio should be ilependent upon its size, its aspect, and the purpose for which it is required. T. Biggs.— We cannot advise you authoritatively. The case had better be submitted to a respectable patent .agent. This much, however, we can tell you, if you have made, and publicly used, or sold the apparatus prior to the date of the patent, and can prove th.at you have done so, you can go on making it without let or hindrance. If tlie patentee, under these conditions, takes proceedings, he is sure to be defeated. A. McCann.— Mildew stains can be removed from engravings by "cleaning or restoring" them. The u.sual method is to treat the engr,iving with a solu- tion of hypochlorite of lime, to which an acid, such as oxalic, has been added, and then well wash with w.ater to remove the bleaching agent. If the engravings are valuable ones, this kind of work had better be intrusted to experienced hands, or good prints may be ruined. Percival & Co. — The so-called " gohl bronze "on the tissues does not seem to us to contain any gold at all ; at any rate, it .all disapjiearedwhen touched by nitric acid. As gold is quite unaffected by this acid, you may draw your own conclusions. We do not think, however, it will prove injurious to the photograph, more especially as the ink upon which the bronze' is dusted and the pajier intervene between the bronze and the picture. E. G.— If the prints turn yellow in the fixing bath, it shows that the solution is out of order. "Two ounces of hypo to the sheet " is no criterion as to the strength of the solution used. That should be four ounces of hypo- sulphite of soda to the pint of water, and should be made fresh for each b.atch of prints If this strength be employed, and the hj'jjo is good, there should be no yellowness in the prints, provided the time of immersion is sufficient. C. Wade. — Prom what you say of the camera, we think it wants thoroughly scraping and re-French polishing. If you are not u]i to this work, and do not have it done for you, we should say the best thing would be to obtain one or other of the commercial furniture polishes, and use ifaccording to the directions su])plied with it.^taking care, first of all, that all dirt is carefully removed with soap and water. If this be not done, the dirt will show more prominently than it did before. Received. — W. Coles, and others. Fallowtield's "Remembrancer." — The last issue of Mr. Fallowfield's list has been received. It contains particulars of a wide range of bargains and novelties. South London Photographic Society. — Fixtures : April 3, Excursion to Ely Cathedral, starting from Liverpool-street Station at a quarter to nine. h. Annual Meeting. 17, Lantern Evening, North Wales, Mr. Jolm A. Hodges. Photograi'HIC Club.— April 5, Tlie " Sandell" Plate, and adjourned discussion on Toning and Fix-ing Baths for Oelatiyio-chloride Paper. 12, Members' Open Night. London and Prontnci.al Photographic Association. — AprU 6, a Paper by Mr. G. F. Williams on JJetrnninatimi of the Speed of Plates. 13, P.aper by Mr. W. D. Welford, Thr Influence of the Hand Camera. Visitors .are welcomed. FoRFARSHtHE International Photographic Exhibition.— The Committee of this Exhibition ask us to say that the 3rd of April is the last day for re- ceiving entry forms from intending exhibitors, and e.xliibitors requiring forms must apply at once. National Photographic Exhibition. — Owing to the Easter holidays inter- vening, it has been decided to extend the time for receiving entry forms to Wednesday, April 5, 1893, .and it is hoped that exhibits may be delivered at the Crystal Palace not Later than that date, Kodak Conceiit. — The Kodak Dramatic and Musical Club gave an enter- tainment to their fellow worlcers and friends in the " Mona Hotel " on Thurs- day, last week. The room was crowded, and the programme very attractive. Much credit devolved alike upon those who man.aged and those who took part in the proceedings. We understand that Mr. W. J. Belton, the well-known pliotogr.apher of 26, St. Paul's-crescent, Camden-square, has been appointed by the Paget Prize Plate Company to demonstrate their printing-out opals and lantern slides before the photogi'aphic societies. Secretaries desirous of arranging a demonstration should apply to the Paget Prize Plate Company, Watford, N.W. Dr. Andresen's Photograi'Hic 1)e\'Elopers ant) Cheiiicals. — We are informed that Messrs. Sharp & Hitchmough (of Liverpool), Messrs. James Woolley, Sons, & Co. (of Manchester), and Messrs. Mawson & Swan (of New- castle-on-Tyne), have been appointed wholesale agents for Dr. Andresen's preparations in tliose to\vn8 and their surrounding districts respectively. The "Shasin Sow a."— We have received a set of the Shosin Soica, a monthly journal th.at lias been running for over a year. Anglicised, the Shashin Shmca is " Photograpliic Chat," and it is published (at Tokyo) in Jiipanese. Mr. W. K. Burton is an occasional contributor, and his articles are (fortunately) printed in English, otherwise it would have been diificult for us to decide as to the precise character of onr young contemjiorary. Photographic Competition at the Welsh National Eisteddfod. — A this Eisteddfod, which takes place at Pontypridd in August ne.xt, the follow" ing photograpliic competition will t.ake place : — For set of not less than six or more than twelve photographs, illu.strating the coal industry from the cutting to the shipment ; prize 6/. For set of not less than six photographs illustrating the industries of Wales ; prize 5?. For set of six instantaneous photographs of a football match, illustr.ating various phases of the game ; prize 11. For landscape pliotograph ; prize 1/. For architectural i>h'itograph ; prize 1/. Adjudicators : — Messrs. T, Forrest, B. Thomas, and Lawrence. Pliotognaphs to be sent to the Genenal Secretary, National Eisteddfod of Wales, Pontypridd. *»* Several answers to correspondents are unavoidably held over till ne.et wee/,: OONTENTS, Faqx multiple-coated films I'JS lens KOG 1!« studio IIUILDINO— II. By O. WAT- MOUOH WEIISTER. F.C.S !»» the influk.sce OF development on giuimtion. by h. j. channon 1117 fukthkr not>s on ouaiacol and allied phenoloid compounds as developers for gelatine dry plates. bv colonel j. WATERHOrSE, l.S.C 108 ENLAROEMKNTS PRINTED ON PRE- PARED CANVAS. I!y W. H. DAVIES 200 P H c 1 T c 1 Q li A P H 1 C INDUSTRIES: MESSRS MORGAN * KIDD'8 WORKS AT RICHMOND 201 Page VABIOI-S METHODS OF ADDING CLOUDS TO LANDSCAPES. By EDWARD DUNMOKE 202 ON THE APPLICATION OF PHOTO- GRAPHY TO SEISMOLOGY AND VOL- CANIC PHENOMENA. By PBOF. W. K. BURTON 20S LEICKSTEK AND LEICESTERSHIRE PHOTOGRAPHIC SOCIETY'S EXHI- BITION 2l« OUR EDITORIAL TABLE 'Xi RECENT PAIENTS 204 MKETINGS OF SOCIETIES 206 FORTHCOMING EXHIBITIONS 205 CORRKSPONDENCE 207 ANSWERS TO CORRESPONDENTS 2US THE BRITISH JOURNAL OF PHOTOGRAPHY. Ko. 1718. Vol. XL.— APRIL 7, 1893. COMBrXING ENLARGEMENTS FROM DIFFERENT NEGATIVES, li' au enlargement from two or more negatives were re- quired to be made on bromide paper, so .is to form cue picture, there are many who wouki not know how to proceed in order to obtain a successful result. We have, indeed, known pro- fessional enlargers to decline to undertake this class of work. Yet, the matter is easy enough, provided the system of pro- tecting the first exposed image with a non-actinic pigment, while the second is being impressed as described a fortnight ago, in connexion with combination printing, be adapted to the circumstances. Of course, as the image after the first exposure has been made is not visible to the eye, the procedure has to be somewhat modified. By way of illustration of the method, let us take two negatives similar to those cited in the article referred to, namely, a group of several persons, and it is desired to introduce a figure or two that is in cne negative into an enlargement from the other. The latter being the principal subject, we will term this the first, and the other the second negative. In the first instance, make a print from each of the nega- tives, and cut out such portions of that from the second one iis are to appear in the enlargement, and stick them in position on the print from the other. This picture is to serve as a guide for arrangement in making the enlargement. Then stop out with black varnish all portions of the second negative, except those utilised in the guide print. In place of stopping out with black varnish, a paper mask cut out from a print may be fixed on the negative ; but, by whichever plan the blocking out is done, it must be complete, as any light that would pass through it would destroy brilliancy. Now take the two negatives together with the guide print into the en- larging room, and put the masked negative into the enlarging, camera or lantern. Project the image on to a piece of white paper, fixed on the easel, of the same size as the enlarged picture is to be, and arrange it in the position it is to occupy in the finished picture, .as guided by the small print, and focus. €ap the lens, and substitute a piece of bromide paper for that focussed upon, then make the exposure, giving such time as this negative may require. It will be obvious that, if the paper were developed at once, the figure would be obtained on a perfectly plain white ground. It is now necessary to protect this already impressed image \(^hile the exposure to the primary negative is being made. Cover the lens with a piece of orange glass ; that will allow of the optical image still being seen, while the light will have no notion whatever on the paper. Now, without disturbing any- thing, neatly paint over the image with a nou-actinio pigment. With prints on albumen paper, almost any water colour can be employed ; not so, however, with gelatine paper, owing to the coating being more absorbent of water, so that a permanent stain of the pigment might be produced. The l)est pigment to use is powaered gamboge — to be obtained from all druggists — mixed with alcohol, as then the gelatinous coating of the paper is not moistened with water at all, and the risk of staining from the colour is thereby avoided. As, however, the gamboge is difficult to see in the feeble orange light, it is advisable to mix some other pigment with it so as to make the brushwork more easily distinguishable. A little finely powdered ivory black answers admirably, and the resinous character of the gamboge serves as a sufficient adhesive to fix it temporarily to the paper. The pigment will dry in a few minutes, though it is not at all necessary to wait for that. When the first exposure has been properly protected, the negative is removed, the paper being left undisturbed ; the other, the principal, negative is now put into the enlarging apparatus, the yellow glass still being kept on the lens, and adjusted so that the enlarged image from it will occupy its right position as regards that already impressed on the sensitive paper. The small print must here be brought into requisition as a guide once more. It is at this stage of the work that the advantage of strengthening the colouring power of the gamboge in the yellow light, with the little black, will be most appre- ciated. After the right position of the principal negative is obtained the image is focussed, the yellow glass still being retained on the lens. When all is ready, the second exposure is made, of course, in accordance with the density of this negative, and quite regardless of what the previous one may have required. The doubly exposed paper is now taken to the dark room, and the pigment removed with a soft sponge or pledget of cotton wool moistened with spirit. It is then ready for developing and fixing in the ordinary way. There is, however, a little precaution to be taken. The spirit, wlien the pigment is applied, has a slightly hardening action on the coating of some gelatine papers, so that they become rather less readily absorbent of water. Therefore, it is a good plan to allow the paper to soak for a rather longer time than usual in the water before the developing solution is applied. This prevents any unequal action of the developer on the two exposures. In the foregoing it has been assumed that the proportions of the images in the two originals are identical, but it often happens that they are widely different. Hence they have to be brought into unison by the greater or less amplification of the one than the other. This often necessitates the paper being removed from the easel and replaced between the two 210 THE BRITISH JOURNAL OF PHOTOGRAPHY. [April 7, 1893 exposures. Therefore an accurate system of registration is imperative. Want of space necessitates this portion of the subject being deferred till some future occasion. WASHING THICKLY COATED FILMS. The tendency during recent years in the preparation of gelatino-bromide plates has been in the direction of thicker films than were in vogue in the earlier days, that is to say, films of greater robustness, both in the matter of silver and of gelatine. Films composed of a more than ordinarily thick layer of gelatine, containing a comparatively small proportion of silver — making up in thickness, in fact, what they lacked in richness — had been tried, as had also the reverse conditions, a maximum of silver salts in conjunction with a minimum of gelatine ; but, while the former were usually found to be slow in action and deficient in range of gradation, the latter were wanting in delicacy, and too often wanting in keeping quality. Perhaps, however, the greatest difference to be found between the two classes of plates was in their physical character, more especially in their behaviour imder the action of developing, fixing, and washing. With the earlier workers in gelatine plates the great difficulty experienced was in conjunction with the length of time occupied, as compared with collodion, in development, and, subsequently, in fixing and washing. It was soon found that this difficulty increased in proportion to the comparative richness of the emulsion in gelatine, and that, if the same quantity of silver bromide were spread upon the plate with less gelatine, the result was an image of equal or greater vigour, and capable of passing through the various operations in a far shorter time. The difference, in fact, in the behaviour of different makes and batches of the earlier plates was very puzzling, if not misleading, and slowness of develop- ment was frequently set down erroneously to want of exposure, and vice versd. For many years past, the necessity has been recognised of a fairly robust film of gelatine, if the plate is to possess the intrinsic qualities now considered desirable, and also the capability of withstanding ordinary wear and tear both before and after exposure and development. But still more recently several of the leading makers have put on the market special plates, bearing films of more than ordinary richness both in silver and in gelatine, and the present season sees the intro- duction of two, and even three, films, coated one on top of the other. The advantages claimed for such special films are suf- ficiently obvious, and need not be discussed here, our object being rather to consider what have been put forward as their disadvantages, or as objections to their use. These objections — if they can be so called — centre, as we have suggested, in the length of time the various solutions take in acting upon the thick layer of gelatine. It stands to reason that, if a careless operator, accustomed to the use of thin films, or those weak in gelatine, gets hold of one of the thicker ones, and tries to treat it in the same way, failure will be the in- evitable result ; but he can scarcely blame any one but himself, as the instructions issued with such plates invariably draw attention to the necessity for increased care, especially in the matter of washing. But, on the other hand, the most careful worker may find the extra time occupied in fixing and washing too great a tax upon him for ordinary work, in which case the remedy is, we think, very simple, namely, to reserve the specially coated plates for the particular purpose for which they are intended, and for all ordinary work to use ordinary films. In thus acting, he will be only following the dictates of common sense ; for, clearly, it must be an unnecessary outlay, both in money and time, to employ say, a triple-coated film — neces- sarily an expensive article — where a single one would answer every purpose as well or better. Let special films, in fact, be reserved for their special work. Where, however, abnormally thick gelatine films are em- ployed, it will be as well always to bear the fact in mind and to act accordingly. In the first place we have to deal with the development, which, like the various other operations, takes place more slowly than with a comparatively thinner film. Except, however, in the matter of a slightly increased difficulty in judging density, no trouble will be experienced here. There are possibly still some operators who adhere to the old-fashioned plan of soaking the film in water before applying the developer, but a very short experience with the thickly coated films will suffice to cause them to relinquish that system for reasons already sufficiently obvious. The first portion of the manipulations in which unsuspected trouble may lurk is the washing after development and before fixing. In the ordinary course of work perhaps too little care is generally given at this stage, though with plates of normal character the result is not very serious. The neces- sity for washing at this stage arises from two causes : to stop development, and, which may appear to amount to the same thing, though it really does not, to remove the developing solution from the pores of the gelatine. The first result is arrived at, for all practical purposes, by rinsing the solution from the surface, after which very little further action will occur; but the application of a very weak solution of bromide will effectually arrest all further action. But if the plate — we are speaking now of one of the thick films — after but a brief rinse, be passed into the fixing bath, with its pores still im- pregnated with developer, another action altogether is set up. The hypo commences to dissolve the, silver bromide, with the result that there are present side by side on the film, not only a soluble salt of silver, but also a reducing agent in the form of the unremoved developer, and until that developer is ex- hausted it will go on reducing the dissolved silver, and so cause fog or veil. This is no imaginary picture, but actually what does occur, as may be proved in five minutes by actual trial. Where ordinary care — the ordinary care bestowed upon a normal plate — is given to one of the double-coated and no more, the result as regards veil is not great, but it is sufficient to take away from the negative that sparkle and purity of colour that belongs to a perfect image. The result does not take the form of a stain that may be removed by means of the alum bath, but consists of reduced silver of precisely the same nature as the image, and can only be removed by similar means — in other words, by reducing solutions. Very many operators are in the habit of examining their negatives by daylight before fixing, a practice which has been over and over again condemned, but still prevails. With the thick films of to-day there is more than ever reason why the negative should be completely fixed before it sees daylight, owing to the greater difficulty of eliminating the developing solution, which, under the renewed action of light, must in- evitably veil the plate. The question of the possibility of preventive measures may be considered, although, in similar matters, we are always in favour of letting matters take their proper course with correct April 7, 189S] THE BRITISH JOURNAL OF PHOTOGRAPHY. 211 troatnieiit— that is to say, with fair washing, and plenty of it. The alum biith, either plain or acidified, may be applied after development ; but it is, in our opinion, objectionnble, for the same rensou already referred to, the difficulty of removing it before fixini; ; for, as has frecpiently been pointed out, the appli- cation of ft solution of alum to a film containing hypo, or vice versd, is hif.;lilv injurious instead of beneficial. But if a solution of mutabisulphite of potash, or, what is nearly equivalent to it, a solution of sulphite of soda, acidified with citric acid, be applied to the film, it may be passed into the fixing bath almost immediately without danger, while the action of the developer will be completely arrested, as well as its staining power destroyed. So far as the subsequent action is concerned of the fixing agent and alum, if used, and their removal, there is, we fear, nothing but patience and care. To facilitate the fixing opera- tion itself, the bath must be of good strength, and the tem- perature kept up to 00°, or even higher. The practice of throwing a few handfuls of hypo into a quantity of cold water, to make an ice-cold solution for immediate use, will certainly not work satisfactorily with thick films. The temperature must be kept up, and, to ensure perfect fixation, a second bath should be used, and plenty of time given after fixing is ap- parently complete. After that, very thorough washing in a changing stream of water is the only means by which the stability of the negatives can be ensured. A Iiarg'e Photographic Society. — We learn that the Photographic Society of Vienna has a membership of over .500. With one e.xception, we in this country have no society with such a memhersbip. Platinum or Platinum -toned Prints.— At the last meetinsr of the Photo<,'rapliic Society of Great Britain the Chairman (Mr. John Spiller) stated that a solution of cyanide of potassium formed a test for ascertaining whether a print he in pure platinum or U a silver print toned by the agency of that metal. In the latter case, the silver forming part of the image is attacked by the cyanide, while the print in pure platinum is unaltered. Meeting' of Exhibition Judgres.— The AfliUation Com- mittee of the Photographic Society of Great Britain and the allied Societies are, we understand, taking steps to call a meeting of E.xbi- bition Judges with a view of arriving at rules for their guidance. It will have been observed that Mr. Andrew Pringle has been appointed Chairman of the Committee, as a successor to the late lamented Mr. Bedford. The choice of Mr. Pringle could not well have been bettered. _^__^^^.^^__^_ Gaiacol (or Ouyacol). — As bearing upon Colonel Water- house's recent experinaents with gaiacol, Messrs. A. Buhal and E. Choay's remarks on the subject may be of interest. They find that the guyacols of commerce are essentially variable products, tlieir boiling points ranging from 200' to 21.3°. None of them contain more than fifty per cent, of definite guyacol, the rest consisting chiefly of cresylol and ciesol. Pure guyacol is a white, crystalline solid, fusible at 28-.')' and boilins at 2b.")-l°. The Central Photogrraphlc Club. — We understand that the Couunittee of the Club, as the result of several meetings, have formulated a set of rules for the government of the Club,, and have also come to a decision as to the financial basis upon which it will be carried on. A recommendation as to suitable premises has also been arrived at. In addition to the foregoing, several other matters of importance will bo laid before a meeting of intending members and others interested in the Club, to be held at the Memorial Ilall, Farringdon-street, on Monday evening, April 17, at eight o lock. XypoBulphlte of Ammonium. — At a recent meeting of the Societi) Fran9ai9e de Photographie M. Labarro detailed the results of some experiments with hyposulphite of ammonium as a fixing agent. He recommended it for paper prints in preference to hypo, used at the same strength. It is more easily eliminated from the print, while it keeps better, and, if any deposit forms, filtration suffices to leave the efficacy of the solution unimpaired. These characteristics, as well as the ready solubility of the salt, its colourlessness, &c., confirm the results of the German experimentalist's conclusions which we quoted a few weeks back. The salt at present is very costly, butM. Labarre promises to give a method of preparation on an industrial scale. " The First Photograph."— According to a daily contem- porary, an interesting object for exhibition at the World's Fiur at Chicago has just been dispatched to America. It is the first sun picture of the human countenance ever taken, and it has been lent ijy Sir William Herschel to the University of the City of New York, and will form a part of their exhibit. I'his Daguerreotype of his sister was taken by Professor Draper, of the New York University, on the roof of one of its buildings, and early in 1840 was sent as a present from that gentleman to the late Sir John Herschel, by whose family it has been preserved to the present time in exactly the same state as that in which it was sent to England. The loan of this in- teresting photograph has been made by Sir William Ilerschell at the request of the llev. Henry M. MacCracken, Chancellor of the University, transmitted through the American Minister in London. The lady of which it is a portrait still lives, at the age of eighty- seven, and a recent portrait of her will be exhibited side by side with the picture mentioned above. NATURALISTIC PHOTOGRAPHY. [Photogrraphic Society of Groat Britain.] Two years ago I withdrew my book, Xaturalistic Photography, and j owe you some explanation for so doing. My researches into tbe sub- ject of vision and perspective drawing were mainly responsible for that act, and if you will bear with me for a little I will endeavour to explain my position. When I first took up photography I was told by the whole photographic world (including optical experts) — told by ail, without exception, that if the photographic observer closed one eye, and placed the other eye at the focal distance of the lens used in taking the photograph under observation, he would see the picture " true to nature." I felt all along that such was not the case, and maintained the " sharp ' or any other photograph, when viewed under such conditions, was not true to nature — to nature as the tioo eye* see it, and hence arose a long and inky warfare. Gentlemen, it was in this as in many other disputes — we were both right and we were both wrong. The opticians were right from the mathematical standpoint, and I was right from the piiysiological and psychological standpoints, and 80 it was evident there were two truths to nature — the perspective or mathematical truth and the psychological or visual truth. After many practical experiments I found the closest truth to natmre in PHOTOGRAPliv {from the physiological point of view) was to be ob- tained by throwing the background of the picture out of focus to an extent which did not produce destruction of structure — that W!VS my limit ; the principal object of the picture being either sharp or just out of the " sharp." This convention I termed the naturalistic method of focussing, and pointed out it had no connexion with a general soft sharpnesn such as that produced b}- Mrs. Cameron's badly corrected " Jamin," or by pinholes, or by throwing the rohole of the picture out of focus — practices all inferior from the naturalistic stand- point, in my opinion, to my method — which is a deliberate and con- scious act to be modified according to circumstances, and no hap-bazard "dodge" Uke the "soft sharpness "' or " bastard naturalism," as my friend, Mr. Balfour, calls the more mechanical " soft-.-iature, a decoration erabodving some fine and true vatural sentiment, the " n without the sentiment (not sentimentalitv) is a mere patchwork of colour, the sentiment without tlio decoration is mere -'literature in the flat," and the truthful illusion without either sentiment or decoration is a mere statement of fact, which ex- plains why Mr. Whistler's masterly "Carlyle" must always be of more interest than (say) a " still-life " picture by the same hand. This may be a fitting place to insert a warning against an error born of misunderstanding. It has been said many times that, by-and- bv photographers will do works of art when they get " soul into tfieir photograplis ; this and all sorts of pretentious rubbish has been written by third-rate painters and second-rate photographers. Gentle- men, the photograph that is fine in sentiment and decoration and true to illusion can never be impi-oi-ed upon any more than can the statue of the Venus of Melos. A perfect work is good for all time, as Mr. ■WTiistler has said. Means are now at the command of photographers to produce the perfect black and white photographic work, though in future increased facilities for producing such work may be found by inventors. P- "• Ehbrson, B.A., M.B. (Cantab.) ( To be concluded. ) ON THINGS IN GENERAL. Onb of the events of the month must be considered Mr. Taylor's paper on Spirit Photoijraphy. What were the results, and how obtained? That is tlie question, and the reply has not yet been given. It was amusing to see the truly logical reply of the veteran fencer to Mr. Downey, who thrust at him straight, " Does Mr. Taylor think there were such things as spirit photographs ? " " The question is outside the subject," was the ready reply. Here. was an exact parallel to the'once famous, or notorious, lecturer who roamed the country under the name of Parallax, delivering a course of three lectures proving, or to prove, that the world was not a globe, but a flat surface. Wonderfully ingenious were his arguments, and re- lentless the logic with which he was usually able to demolish the opponents who disputed with him in the public discussion that followed each lecture. The usual taunt cast at him by the overthrown logicians was, " Oh, you don't believe the earth is flat, after all'.' Mr. Taylor's reply was on all fours with his. Another paper on a perennially interesting topic that was bound to attract attention, if only from tlie personality of the writer, was that of Dr. Emerson on " Naturalistic Photography "—almost the same old story and stale arguments, the trite aphorisms that are always used to adorn the subject, all the more interesting as being from the mouth of a recusant teacher. This time, however, Dr. Emerson has soared to a height of repudiation that the most rampant of photographic detractors has not attained. Not content with denying all claims to fine art, he will not admit photography to be even an art. Now, on the point of fine-art photography, as those (if any) who give my lucubrations any thought will be aware, I have consistently held that it is not only an art but a fine art— one, it is true, with an extremely limited range, but still a fine art. I never have seen a satisfactory reply to two queries I make. If there is no fine art in photography, how is it that it is possible to produce by photography ascene, a view.or a representation ( I will not use the word " picture " for fear of offence) that no artist can toll by simple inspection whether it is an engraving in one class, or a sepia or monochrome painting in another ? Secondly^ if a painter of repute took pains to learn photography, would, or would not, some of his results be more artistic than those of the photo- grapher with no art education ? If the reply be in the affirmative, would not the cause of the difference, the art feeling of the painter put into his photographic work, be rendered evident to those who looked at the photographs ? Dr. Emerson argued that sharp photographs were not true to nature ; but, using his words exactly in the sen-ie he uses them, it is very certain that many a painting of acknowledged ex- cellence is not true to nature, and indeed is further from it than most photograi)hs. Bearing on this topic, Mr. H. W. Bennett's paper in last week's JotniNAL may be read with considerable interest, and I may be forgiven for quoting from it. " The indiscriminate use of a method of treatment or printing surface, suitable only under special conditiona is certainly not artistic— it is either studied eccentricity or want of judgment." Then, again, " etchings or engravings are invariably on smooth surface paper, and water-colour drawings (excepting those of very large size) on that of fine grain or moderate texture ; but they are not considered inartistic on that account. Those photographer* who affect extremes in either roughness of surface, or out-of-focus methods, or misty, gloomy effects, might study with advantage the works of leading etchers, which show that smoothness of .surface, fineness of definition, delicacy of treatment, bright and gunny scenes are not inconsistent with the highest artistic quality." We have further matter in the same issue of this Journal which will well repay careful perusal, in a paper by Mr. Xanthus Smith. He writes most justly on the relation of part to part, a most im- portant consideration in photography. What he says about fore- "•rounds and backgrounds, under particular cases, is pregnant with food for thought. He appears, however, to be wrong in one part cf his paper, an unimportant part as regards photography, though the writing is so involved as to leave his meaning in some obscurity. He says that we feel the shortcoming of art, which cannot in any way advance or recede beyond the surface plane of the canvas or paper, except as in the case of scenery in theatres. Now, as a matter of fact, paintings on a flat surface have been exhibited in which advance and retreat were so positive that ninety-nine out of a hundred spectators were utterly unable to say whether it was s painting or nature that was before them. I am not sure whether I have appre- hended Mr. Xanthus Smith's meaning, taking his preceding paragraph into consideration, but I think I have. The paper by Mr. H. J. Channon on the influence of development on graduation is an excellent contribution to a much-discussed subject. He shows clearly by experiment that, as every careful and practical photographer knows is the case, graduation can be controlled by development. Messrs. Hurter & Driffield say in effect, in their original paper, that has been the basis of many arguments, that it cannot be so influenced. It is, however, of little use to prove the existence of this power of control, for if these experimenters intervene they will be able to point to a letter in which they say that they have not asserted the impossibility of this control. This blowing hot and cold with the same breath is disconcerting to a searcher after truth ; thus, after all, it may be made to appear as merely incidental, and not proper to the argument proper of Messrs. Hurter & Driffield. I will conclude my letter by expressing the great pleasure I felt on reading a letter (which I hope will be the forerunner of rigid investi- gation on the subject) from a firm of English card-manufacturers referring to the integrity of the mounts supplied to photographers. This is far above everything the most important question of the day. I hope the Editor will put in italics my assertion that more faded silver prints are due to the mounis they are printed on than to all other cawes put tor/ether. Photmjraphers have tamely submitted too long to their pictures being ruined from this cause. They shoidd call upon the Photoc/raphic Society of Great Britain to select a committee to investi- gate the mtdter. The result would be a gigantic surprise. Hundreds of thousands of photographs are yearly placed upon mounts that icill teith certainty lead to their utter ruin. This matter should be investi- cated thoroughly by every means at command till an ex-cathedra statement can be given to photographers everywhere. Fbeb L.ufCB. VARIOUS METHODS OF ADDING CLOUDS TO LANDSCAPES.* Great diversity of opinion exists with regard to masking. The following plans are adopted by various operators:— Painting out the sky on the landscape with opaque colour or black varnish, then making a mask of a print and laying it in clo-se contact with the pnnt to be clouded below the cloud negative. This plan leads to much trouble ui spotting the finished print, for it is almost impossible to get them in accurate register, a white or dark line showing here and there round the edges. The fact of painting out a sky invariably destroys a proper • Conclnded from page 203. 214 THE BRITISH JOURNAL OF PHOTOGRAPHY. [April 7, 1893 artistic effect, however correct the register may be in all ordinary landscape). Strictly architectural or sea views, where the line of the horizon is not diversified with hills, are the only subjects that can be 80 treated with a fair chance of success. If it can be possibly avoided, never block out a sky cl>se up to the subject on the face, the tint on it is an advantage rather than other- wise. An undoctored sky printing rather patchy and uneven will look all right on the addition of clouds. A maslc, roughly following the outline of the landscape and laid mttside the cloud negative, is better : but a duster or cloth roughly folded and laid over the part, to be protected, is best of all, and a plan I always adopt. It occasion- ally happens that a picture with a church spire or similar brightly lighted object projecting above the line of the horizon into the sky, requires protection from the light more effectively than can be managed with ordinary shading. If this occurs, paint over the pro- jecting object with a thick coating of gamboge on the print itself, and let it dry. It will all come off in the wash water without leaving a stain or trace, and is by far the best method of doing it. An alternative plan is to make a print, cut out the sky and the projecting objects of importance, but not otherwise following the outline, and gum it on to a piece of glass sufficiently large to cover the whole of the sky portion. This mask can be laid on the prints and the cloth tised as already directed. The reason the ffjass must be large enough to cover the whole of the sky and distance is to prevent the edges of it making defects on the print. The next plan of adding clouds is by painting them on the negative itself. As compared with real clouds, this is but a make shift ; still there are occasions when this plan has its advantages. For com- mercial work, where large numbers of small pictures have to be printed, it would scarcely pay to double print each one ; then, painting on the negative adds nothing to the trouble after being once done. A well-painted sky would pass muster as a real one with nineteen of twenty of the general public. Even the knowledge of its being hand work will not decrease but rather enhance the artistic value of the subject. In many cases mere suggestions of clouds are sufficient for the purpose of breaking up a blank space. The density of the sky in the landscape negative determines the best plan of proceeding. When a sky prints absolutely white (but very few do so), it is no use painting clouds on it ; but if there is the least suspicion of tinge when con- trasted with unprinted paper, a little thin black varnish put on the back with the finger tips or short-haired brush in the form of clouds, will break up the blank space and show plainly on the finished print. If it is permissible to doctor the negative itself, the sky portion may be reduced by any of the usual methods before doing anything to the clouds, which can then be put in in the orthodox fashion. It is necessary to prepare the backs of negatives for painting upon, either by grinding the glass itself with moistened emery powder rubbed on with a small block of glass, or by attaching some papier mineral to it with gum. Providing the glass is quite flat — patent plate, for instance — grinding is far and away the best; but with irregular surfaces the labour incurred to get an evenly ground surface is so great and occupies so much time that the papering process is generally adopted, albeit it may require more frequent renewals. The back of the sky portion of the negative being prepared, cloud.<< can be painted or drawn upon it with India ink or black lead. If paper is used, the lower edge of it shoiUd be made to follow the out- line of the landscape in such a way that any little difference in density will not be very observable. The distance itself is often improved by the covering of paper. It seldom happens that any improvement can be made in the clouds on the face of the negative, although much may be done on the landscape itaelf . Negatives so prepared must not be printed in the sun, or the edges of the paper will make defects on the prints : as the paper gets soiled with use, this precaution becomes more and more necessary. There is no trouble of this kind if the surface of the glass is ground and the clouds worked on that. Clouds may be drawn on a separate piece of ground glass, and the two printed together; but this plan scarcely commends itself to the busy printer, who very often resents any addition to the risk and trouble of his work, however .slight. Natural clouds may be made on a film and attached to the negative providing the sky is sufficiently thin, but with most of those of the usual density the delicate gradation of natural clouds is quite lost, and they really do not look so real on the finished print as the imitations made in a coarser manner. In almost all instances the prints on which artificial clouds have been impressed are much im- proved by slightly tinting down the whole of the sky by a short exp;>sure to the light, it seems to harmonise them with the landscape better than any other plan. When we print a cloud negative on to a print prepared for it, tne print is laid down on a perfectly fiat surface, glass for instance, the cloud negative properly adjusted, a cloth thrown over the landscape portion, and the whole exposed to diffused light for a sufficient time to get the required depth of printing. When we examine the picture to find out how the printing is pro- gressing, great cai-e must be exercised not to shift the arrangament and blur the impression ; if the hand is firmly pressed on the lower edge of the plate, so that it acts a hinge and the upper edge raised, the progress of the work can be ascertained without difficulty. To print clouds by development is a much more troublesome task, for we cannot see what we are doing at the time. Artificial light is prefer- able for this work, not only on account of its being more under con- trol, but because of its uniformity in compari-son with daylight, an exposure of a definite number of seconds, at a uniform distance from it, will give identical results, other things being equal. Let us suppose that the landscape has been printed; we mark with a lead pencil the space occupied by it on the edge of the print to act as a guide and also on the frame, the cloud negative is adjusted, a piec-t of cardboard, with the edge roughly made to follow the outlines of the land-icape, and large enough to cover the whole from the action of the light is cut, the exposure is made, during which time the card is kept gently moving in front, always keeping the landscape part covered, and vignetting it, as it were, into the .sky. As a matter of economy, it is best to try various exposures on small pieces of paper until one is found to suit the landscape by causing the sky to develop the proper strength with it. Once fimnd, there will be no further trouble in this respect. It is best for all exposures by gas- light to filter the light through a piece of ground glass. The illu- mination will be found more equal, and very little difference in the exposure than when the naked light is used. The distance of the print from the liglit should not be less than two feet. A fairly Ion"' exposure is much more under control than a rapid one, and more espe- cially advocated for this class of work. A cloud negative that would be suitable for printing out may be quite unworkable for develop- ment. Clouds made specially thin are best. A strong, bright nega- tive will probably develop patchy, although it will give unexceptiou- ally good results for printing out. With platinotype an actinometer of some kind is required, as there will be no visible image until development. As in the bromide pro- cess, a few small pieces of paper should be used as trials, and, when the right exposure is secured, a small piece of sensitised silver paper laid on the frame in which the printing is done, or in the same lignt, on attaining a certain tint will be a good future guide. In other respects it is precisely as a printing-out process. One is able to see the landscape, and can judge of the best position for the clouds to be pl.iced without any difficulty. General directions may be summed up by saying : Always print the clouds subservient to the landscape, never allow them to encroach on it, or show through light objects in relief against it, or exhibit any decided line of junction in any part whatsoever. Edward Dunmobk. PHOTOGRAPHY AT THE CAPE OBSERVATORY IN 1892. I RECOLLECT ouce re.ading a story about an individual who resolved to be his own architect, and design and superintend the building of his own house. All went well until the ground floor was finished, and then it was discovered that he had forgotten to provide a staircase. Most new schemes suffer from such defects. It is easy to design, but when the practical working (^f the scheme comes to be carried out it is surprising how many essential details have been oveilooked. So it was with the International Star Chart. Not that a part so important as the staircase was unconsidered, but it was found that in many important respects our knowledge of stellar photography was in its infancy, and these points had to be investigated. The instruments were ready and set up, the heavens had been parcelled out to the par- ticipating observatories, but much experimental work had also to be distributed before the work could be really commenced on a uniform plan. What exposure was to be given, and were screens to be used or not as guides to the various magnitudes ? what degree of accuracy was advisable as to the pointing of the instruments? should the catalogue or the chart plates take precedence ? and so on. It is not my purpose to take all the various questions in detail and state how they were worked out. It will be quite enough for the general reader to know what is now actually being done, and with that end in view I will give an outline of the various operations carried out now the work is in actual progress. But first, and this is the chief reason for my writing, I want to give a few particulars of some researches of a purely physico-astronomical character that were carried out here before the regular work was definitely started. Some AprU 7, 1893] THE BRITISH JOURNAL OF PHOTOGRAPHY, 215 of those results are now being exhibited in the form of lantern slides in England. Few in number, they might furnish matter for several lectures in astronomy, but too long a description at an ordinary lantern show would be out of place. Hence I only penned the slightest sketch by way of description, and tliat sketch I wish to supplement here in order to indicate to those interested what important problems yet await solution that only photography can elucidate. J'his article, then, let me say at once, is an elaboration of my brief article in The BaiTisir JouuNAL Puotoquaphic Almanac. Basing my remarks on the lantern slides, let us consider tliem first. Taking a general view of it, it may be regarded as, in one respect, a specimen of the shorter exposure or catalogue work of the Inter- national scheme. The slide is on about the same scale as the Inter- national, but, being only one-fourth the size of tlie regulation star plate, it only shows one-fourth of what the International Catalogue plate would show. The exposure of five minutes which it received would be rather less than that given to a Catalogue plate on an average night; but, as it was taken on a good night, we may speculate on its showing stars up to, or about, the eleventh magnitude. The diameter of tge slide U about twice that of the moon : consequently ■we must not expect to find many stars on it tliat the naked eye would see. Yet there are a very considerable number, for it represents one of the richest parts of the sky, but not one of the many stars visible in the photograph can the unaided eye distinguish. Viewed parti- cularly, it is of special interest, for not only is that region one of the brightest parts of the Milky Way, but it is centered by a star which is one of the still unsolved problems of tlie stellar universe. ?; Argus, the central star, is of a reddish colour, and about the eighth magnitude. " It seems to me it is a little brighter than it was, but I don't know ; that we shall have to look into," said Dr. Gill when he saw it last. The great astronomer Halley found it visible to the naked eye, and classed it as of the fourtli magnitude in his catalogue, constructed a.d. 1677, the first catalogue that can be depended on. Lacaille, who did some splendid work here in the middle of the last century, ranks it as of the second magnitude, and the later catalogues of Brisbane — Johnson, Fallows, and Taylor — also give it as a " second." When Sir John Herschel first saw it, in 1834, it appeared as a very large star of the second magnitude, or a very small one of the first, and for three years its magnitude remained apparently unchanged. "It was on the 16th of December, 18.37," says Sir John Herscnel, " that, resuming the photometrical comparisons in question, in which, according to regular practice, the brightest stars in sight, in what- ever part of the heavens, were first noticed, and arranged on a list, my astonishment was excited by the appearance of a new candi- date for distinction among the very brightest stars of the first magnitude, in a part of the heavens with which, being per- fectly familiar, I was certain that no such brilliant object had before been seen. After a momentary hesitation, the natural consequence of a phenomenon so totally unexpected, and, referring to a map for its configurations with the other conspicuous stars in the neighbourhood, I became satisfied of its identity with my old ac- quaintance >i Argus From this time its light continued to increa.se. On December 28 it was far superior to Bigel, and could only be compared to a Centauri, which it equalled, having the ad- vantage of altitude, but fell somewhat short of it as the altitudes approached equality. The maximum of brightness seems to have been obtained about January 2, 1838, on which night, both stars being high and the sky clear and pure, it was judged to be very nearly matched indeed with a Centauri, sometimes the one, some- times the other being judged brighter." On the twentieth it was " visibly diminished." By April 14 it had so far faded as to bear comparison with Aldebaran. But again it advanced in lustre until it was almost as bright as Sirius, according to the Rev. W. S. Mackay, 1843, and Mr. (afterwards Sir Thomas) Maclear, Astronomer Koyal at the Cape. In 1844 it had again slightly diminished, but at the beginning of 184.") it had blazed out again, and then began to decline. A similar phenomenon had previously been noticed by the traveller, W. J. Burchell, long after Halley 's observations, but some years pre- yious to those of Sir John Herschel. Now, as I have before stated, it is only of the eighth magnitude. Will it ever blaze out again ? As I hope to show, there is some probability of its so doing. It Is not a temporary star. Some stars liave suddenly appeared, and just as suddenly been extinguished ; but rj Argus, bright or faint, has been visible for centuries. And now let us take the second photograph, that exposed for forty- five minutes. The stars visible in the five-minute photograph have visibly increased in size, owing to the longer exposure ; but, in addi- tion, are a large number of star discs, not visible in the first slide. Itoughly speaking, all the stars visible up to the thirteenth magni- tude now appear, and possibly even a few fainter ones stilL But note, too, that round some stars a curious phenomenon is appearing. Clinging to those stars, as it were, is some nebulous matter. It is not halation, for halation round a point appears in the form a ring, whose diameter varies according to the thickness cf the glass. Be- sides, the plate was backed with that best of all backing, optically speaking, a backing that ^ves some trouble to manipulate though, common Brunswick black, procurable from any oil and colour shop. A glance through the ten-incli telescope, moreover, reveals to us a great deal more than appears in the forty-five minute photograph ; the small field embraced by the eyepiece is full of nebulous matter, save and except a shoe-shaped darli portion in the centre, midway between the toe and the heel, lying to one side of the red star 7) Argus. With an exposure of about three hours, we get on the photographic plate a repre-'^entation of what is to be seen in the telescope, but it is far more definitely outlined. In addition to the nebulous matter is a vast congregation of stars — as many stars as Sir John Herschel saw in his twenty-four inch reflecting telescope, but hundredfold as many stars as he dared attempt to map. To map as many stars as appear in the three-hour exposure would have taken him best part of his natural life. Y^et photograpliy has done it in three hours. And now we go on to the twelve-hour exposure. It was not done on one night. Four nights were occupied. The slide was shut and covered with dark cloths, to exclude light. When the next night came, the star ij Argus was brought back to its same position on the cross wires, everything connected with the eyepiece of the observing telescope being clamped up rigidly. The photograph shows more of the nebula) than Sir John Herschel could depict with months of patient watching and careful toil. It might have shown more still, but, unfortunately, the nebula surrounding i; Argus is not particularly actinic — far from such in comparison with other well-known nebulse. But the stars ! Slowly but surely their light has been gradually accumulating on the sensitive film. On a space of sky that might be covered by a shilling held at arm's length are to be seen something like 200,000 stars — only six times as many as have been catalogued in the space of, say, ten years, by an in- defatigable astronomer, backed by an efficient staff. But let us disregard the stars. The nebula is actinically faint, and therefore better suited for eye observation. But what does Sir John Herschel say in reference to his own drawing ? " The accurate representation of this nebula with its included stars has proved a work of very great difficulty and labour, owing to its great extent, its complicated convolutions, and the multitude of stars scattered over it. To say that I have spent several months in the delineation of the nebula, the micrometrical measurement of the co- ordinates of the skeleton stars, the filUng in, mapping down, and reading off of the skeletons when prepared ; the reduction and digestion into a catalogue of the stars so determined, and the execu- tion, final revision, and correction of the drawing and engraving would, I am sure, be no exaggeration. Frequently, while working at the telescojie on these skeletons, a sensation of despair would arise of ever being able to transfer to paper, with even tolerable correctness, their endless details. However, b)' breaking it up into parts, and executing each part separately, it has been accomplished, and I trust with such exactness as may afford a record capable of being appealed to in future, whether the question of internal changes of the form and situation of the nebulous branches shall be gone into." Comparing Sir John Herschel's drawing with the photograph, it is strikingly noticeable how the draughtsman had seized the most con- spicuous features, and, so far as they agree witli the photograph, with remarkable fidelity. But in the photograph also is a vast amount of small detail that is absent in the drawing, to say nothing of the multitude of stars which the telescopic camera has charted down with unimpeachable fidelity. The great astronomer wlien he made some of the important discoveries that advanced the early progress of photography, when he took, over fifty years ago, the first photograph on silver chloride obtained in the camera, little knew to what goal bis efforts would ultimately lead ; and no one would have rejoiced more than he to see the ])resent state of the science, though his own labour of love, the work of many a night's watching and day's recording was to be superseded by a few hours' work of the gelatino-bromide plate. Carefully as his drawing was executed, too, and intended as a foundation for the observation of changes in the nebula, he little iriieseed that doubt might be thrown on the accuracy of hi" eye. Y'et there are vast differences between the drawing and the photograph. In some parts, portions of the nebulie are fainter or brighter in the one than in the other. One noticeable feature is a zigzag stretch of nebulous matter, visible in the drawing but entirely absent in the photograph. How are these discrepancies to be accounted for.' Was it that, in drawing the separate 216 THE BRITISH JOURNAL OF PHOTOGRAPHY. [April 7, 1893 portions of the nebula on different nights, some parts f^ot unduly represented, according to the atmospheric conditions being more favourable ? Scarcely ; for Sir John was not the man to omit con- sidering the drawing as a whole, though the parts were done at different times. Was it that — in the fainter portions, for instance — the imagination had greater play ? Perhaps ; for we know that the eye has not proved entirely trustworthy in recording many physical phenomena. Or may we look for the cause in the supposition that various parts of the nebula are richer than others in rays of higher refrangibility ? Possibly : for such affords a simple and reasonable explanation." All these and other questions naturally arise; but I consider it not improbable that many real changes may have taken place in the intervening sixty years, more especially when we consider the remarkable changes that have taken place in tlie star itself. But to decide this point we want the uniaipassioned mechanical observer, and photography alone answers to this description. Time will tell, and future photographs of the nebula will be eagerly looked for. Photography ^"ill set this question at rest, as it has already decided so many others. A question that naturally arises is, Is the star behind or before the nebula and disconnected with it, or do star and nebula form part of the one system ? On this point the drawing and the photo- graph are in accord. No change can be detected in the position of the star relative to the nebula, and it is only reasonable, therefore, to assume that the two are part of one system ; it is the conclusion that, in the present condition of our knowledge, is the more justifiable. And what is the connexion between star and nebula ? Can we explain the sudden outbursts of splendour in the star by the impact of meteoric masses forming part of the nebula surrounding it ? If not, ill what other way? Photography, in the future, may reveal that to us. In one corner of the original photographs, but not in the lantern .slides, are two stars, which in the three-hour exposure begin to show surrounding nebula. In the twelve-hour exposure this nebula has extended so far as to show that there is a real, though in the telescope invisible, spiral nebula connected with and enveloping both stars. In many parts of the Milky Way photography is beginning to reveal many analogous phenomena. Years of patient labour are required to elucidate these many points that are outside the range of the regular Observatory work. The foundation has been laid by the Herschels. To take that work, and follow it step by step by ihe photographic method, would enlarge our knowledge of the universe in an extraordinary work, and that is why I suggested the research in The British Joubnal Photogkaphic Almanac. I foolishly talked there about the " young millionaire." Happily, much more modest pecuniary possessions are all that is required. I trust that I have not written at too great a length to tire the patience of Editor and reader. As it is, I have omitted to describe two important photographs exhibiting the power of the photographic compared with the older method. I must reserve them for another article, when I will also, by describing in brief detail the ordinary international work as carried on here, conclude the subject of the title of this article. C. Ray Woods, Photographic Assistant at the Cape Observatory. ON THE APPLICATION OF PHOTOGRAPHY TO SEISMOLOGY AND VOLCANIC PHENOMENA.* Special Adaptations of Photogbaphy to Seismology. We now come to a consideration of more special adaptations of photo- graphy to seismology, and, to avoid the necessity for repeating his name every few lines, I state here that nearly all these adaptations are the work of Professor John Milne, F.E.S., the writer sometimes giving assist- ance in some of the purely optical and photographic parts. Some two years or so ago, an attempt was made to find whether any elrnnge in electrical potential between the earth and the atmosphere preceded, accompanied, or followed earthquakes. An instrument to keep a continuous potential record was devised on the following lines : — One terminal of a mirror galvanometer was connected with a metal plate in a well of considerable depth, the assumption being that the potential of the well water would be the same as that of the earth at the same depth. The other terminal was carried to a metal plate at the ground level. A beam of light was thrown on the galvanometer mirror and, being reflected, was received on a photographic plate, narrow and long, kept moving slowly in the direction of its length by clockwork. A con- tinually changing potential was shown, and there were several cases in which there were decided deflections at the tunes of earthquakes, but ' Concluded from page 203. there was not sufficient consistency in these to make it evident that they were the result of anything but the mechanical effect of the shocks on the galvanometer. The subject is one that yet requires attention. Earth Tkemoiis and Earth Tilting. There has been much investigation of " earth tremors " and " earth tilting." We are accustomed to look on the "solid earth," apart from its planetary motions, as the very type of what is stable and steady, but it is now known that it is never at rest. It is always trembling, and there is reason to believe that its surface is often slowly tilting in one direction or in another. These motions are extremely small ; to get indications of them, much less to measure them, is very difBcult, and, up to the present, it has been impossible to separate them one from the other with certainty. Thus no tremor recorder has yet been made of which it can be said with certainty wliether it is recording true tremors or " tips." An ordinary pendulum will be affected by " tilts " but not by tremors, unless these happen to coincide with its period. The difficulty is to record in any way the extremely small motion of the bob of the pendulum. A partly successful attempt was made to solve the difficulty by photography. A silver bead was suspended by a silk fibre in a hollow stone column, which prevented atmospheric influence. A beam of light was thrown on the bead, and the image of the point of light, passing through a micro-objective placed vertically below the bead, gave an image of the spot of light on a plane at a considerable distance below it, along which a photographic plate could be made to travel by clockwork, the motion of the bead being, of course, greatly multiplied — being, in fact, multiplied in the ratio of the distance between the bead and optical centre of the lens, • and the distance between the optical centre of the lens and the plate receiving the image. A word or two should be said on the optical principles here involved. If a silver bead were a perfect sphere, or indeed, it the surface were everywhere convex, the form only approximating to a sphere, the spot of light produced by the reflection of any source of light, say a lamp flame, could be made as small as might be desired, without being reduced in brightness. The further the source of light is moved away from such a bead, the smaller becomes the spot, but its brightness remains the same, and is, indeed, at all distances, leaving air absorption out of the question, the same as the source of light itself, less a constant percentage of loss on account of absorption of light at the reflecting surface. This arrange- ment is, in fact, the " artificial .star " used by opticians in testing tele- scopic and other objectives, when it is not convenient or possible to foons on an actual star. It was thought that, in the case of this instrument, as the spot of light could be made indefinitely small at will, the image of the spot could be made as small as might be desired, however great the amplification. It was found, in practice, that this was not the case. If the amplification were great enough to be useful, the spot of light was too large to draw anything but a very wide line. The lens was a high class Jinch micro- objective, and the fault was probably not in it. It is likely that the bead was not really convex throughout, but that the surface consisted of minute facets, or more likely grooves. It a bead of mercury could by any means be used the results would probably be much better. Excellent results have been got by the aid of photography by the tremor recorder described in a report on the " Volcanic Phenomena of Japan.' (BritUh Association Reports, 1892.) The only ditticulty here is that it cannot be known for certain whether these instruments are showing tremors or " tips." In this case the light passing through a narrow vertical slit, behind which there is placed a small lamp, passes farther through an objective, is received on the mirror, and is from it reflected on to a horizontal slit in the front of a box which contains a photographic plate moving vertically by clockwork. Of course any motion of the mirror of the instrument, whether produced by tremors or " tips," is amplified by the beam of light, whilst the hori- zontal slit cuts off all superfluous light, so that a spot only reaches the plate. Daily observations were taken on plates twelve inches long, two and a half inches broad, moved by clockwork, at such a rate that they took twenty-four hours to travel their whole length. With this slow travelling vibrations were not separately registered. The breadth of the line across the plate indicated the ampUtude of the vibration at any particular time, and showed that there attained a maximum at intervals five to ten minutes. In working with these slow speeds it was found that the light of a small kerosene lamp was ample, if the plates were rapid, but it was considered advisable to get a record of the actual separate vibrations during " tremor storms." To do tliis the plate was caused to travel rapidly, at the rate of twelve inches in about thirty seconds. With this rapid travelling the light of a lamp was quite inadequate, and a * More strictly one of tUc ".principal points " of the len^. April 7, 1893] Til BRITISH JOUUNAL OF PHOTOGRAPHY. 217 maguesinm light produced by tho burning o[ magnesium ribbon was ugod. I prepared a diagram to illustrate the sort of records that wore got on the slow travelling and on the iinick travelling plates, showing tho result on II slow travelling plate, in actual size, representing a part of tho plate only ; and showing tho result on a quick travelling plate, redaced to its present size from a leugtli of twelve inches. Of course the line of liKht that did the actual photographic work was an imago of tho slit, which slit was made very narrow. I was surprised, in connexion with tliis. to find how little difference it made what kind ol objective was used to oast tho image. A high-class portrait objective was suggested, as on account of the perfect correction for both the spherical and chromatic aberration of the pencil's axial, or nearly so, I thought that the results would be much superior to those got with an inferior lens. To my surprise there was very little difference between the results got by the use of such a lens and those got by the use of a single double-convex, or " crossed " lens, not even achromatised. In 188V MM. Fouque and Michel Levj- described a set of experiments they had made to determine the rate of transmission of shook of an earthquake nature, jiroducod bj' exploding dynamite, and in other ways, tlirongh different kinds of soil, using a photographic arrangement for recording the time and durations of vibrations. An incandescent electric lamp threw a beam of light at an angle through a lens and on to the face of mercury in a dish. The reflected beam of light was brought to locus on a revolving plate. If there were no motion, of course tho light simply drew a circle ; if there were any vibration, the beam of light was set in motion, and the circumference line of the circle was widened, and became indistinct. Thus the beginning, duration, and ending of the motion were indicated. Contemplated Applications of PHOToonAPHY. So much for what has already been done. It may be worth the neces- sary space to say a word or two about applications of photography that are, as yet, only contemplated. In the case of all seismographs at present in use, the " steady point " is a comparatively heavy mass of metal. Tliere are no objections to this in the case of slight earthquakes, but, in the case of great ones, when we have tilting the mass is liable to over-swing the mark and to exaggerate the motion. There is also the objection that it is never known for certain whether " tips " or lateral motions are being registered. It is possible that this difficulty may be got over by the use of very light " steady point," but, in such a case, the ordinary method of drawing the record by a point scratching through a smoked film or glass will not be admissible, as the friction would be too great. It will be necessary, in this case, to lesort to photograpliy, which introduces no friction to all. At places where no regular seisological observatories are situated it is often desirable to have a record of the time of occurrence of earthquake. The simplest way of doing this automatically is to have an arrangement whereby a clock is brought to a stop at the moment an earthquake begins. One objection to this anangement is that thus stopping a clock makes it often dillicult for observers to reset it at standard time. It has been suggested tliat a photograph of the face of a common watch might be taken at the instant an earthquake occurs. Were earthquakes so con- siderate as always to take place in the day-time, there would be very little difficulty about the affair ; but unfortunately they are not, and the difiB- 'Culty is about a night illuminant, because, of course, the exposure must be very short to show the seconds hand of a watch fairly well, and this necessitates a very bright artificial light. Some experiments made several years ago were very encouraging. Since then " magnesium cartridges" have been introduced, and there is no doubt that an arrange- ment could be devised whereby one of these could be ignited at the instant an earthquake occurred, and, if the ignition took place fairly near the dial of a watch, a photograph showing the liands could be made even with a lens of only moderate angular aperture. It is somewhat doubtful, how- ever, whether such an instrument could be placed in the hands ol one unskilled in the use of scientific instruments, and the object of watch photography is to get on appliance that may be placed in the hands of any one. On the other hand, it has suggested itself to the writer that the difficulty might be got over by fixing a minute silver bead on the end of each of the three hands of the watch. On the principle described above, in connexion with the pendulum tremor recorder, the spot of light reflected by such beads ought to impress themselves on a plate with a fairly short ex- posure, even if the light be nothing more powerful than an ordinary lamp. The arrangement whereby a camera, with shutter to bo released by an earthquake, a watch, and a lamp might be enclosed in a box so as io effect the desired result would not be complicated. There are various other investigations in coaneiion with which photo- graphy may possibly be used. Thus, although the motion of an earth particle during an earthquake has been very faurly investigated, there arc still wanting data as to the relative motion of two earth particles at some distance from each other. It is of great importanoe to know what such relative motions are, as, according to whether the motions of the earth particles at some distance apart are nearly in the same phase at the same time, or are in entirely different phases, is the effect of an earthquake on a building due to the inertia of the mass alone, or is due to racking. The construction of buildings to best resist these two destructive influences would be entirely different. It is possible that photography may be used in connexion with such investigations, but it is more probable that entirely meohanioal means will be employed. If the very long water level (at least several miles) proposed some time ago by Professor Milne to discover whether there is any slow, tipping motion of the land in certain planes, be carried out, it may be found convenient to register the height of the water at the two ends of the level photographically. Professor W. K. Burton. ON THE THEOBY AND PBACTICE OF INTENSIFICATION. [Croydon Microscopical and Natural History Society.] Either from under-development or from the exposure' not having been sufficiently prolonged (or it may be from other causes), a negative is sometimes found not to have sufficient density for printing purposes. Due regard must, however, be had as to the final use to which the negative is going to be put. Thus, for all kinds of paper printing, t'.'/., albumen, gelatino-chloride, or platinum, a strong negative would probably yield the best result ; but for enlarging, bromide work, and lantern slides a weaker negative would possibly prove more satisfactory. Preliminary Processes of Intensification. When it has been decided to resort to the intensification of a negative, certain preliminary processes are essential, i.r.: — 1. — All trace of hypo must be absolutely removed ; very thorough washing, followed, if there is any doubt, by immersion in — (n) Peroxide of hydrogen, two drachms of tho 10 vol. solution to five ounces of water. Soak for half an hour, and then wash. (b) Alum solution, freshly made, and acidulated with hydrochloric add (about half an ounce to a pint of saturated solution of alum). The acidification is desirable, not only to assist in decomposing the hypo, but to keep the gelatine soft, as alum alone hardens the film, and renders the subsequent removal of the soluble matter difficult. Soak for half an hour, and then thoroughly wash. (<■) Iodine solution, made by dissolving iodine in a strong solution of potassium iodide till it is of a black colour, adding some of this to water till of a sherry colour, and immersing the plates. When a blue colour is persistent, all the hypo is gone, and the plate is then rinsed, treated with sodium sulphite to remove excess of iodine, and then washed. The absence of hypo may be proved by testing the washing water from time to time, either with iodide of starch, which has its blue colour de- stroyed if hypo is still present, or with potassium permanganate, which has its beautiful pink colour destroyed and manganese oxide precipitated by hypo. 2. — Any trace of fog or veil must be carefully removed, because it must not be forgotten that any such fog or veil would be intensified too, a result not to be by any means desired. This is best removed by the careful application of a reducer, and possibly the hypo and fenicyanide of Howard Farmer is the best, care being taken to thoroughly eliminate the hypo. 3. — The negative must be soaked in water for half an hour if it has become dry, because it should be thoroughly and uniformly wet to ensure success. Thus it will be seen that a certain amount of work has to be done before intensification proper is commenced. This prelimmary work is, we are afraid, often neglected ; in many cases we know it is so, with the usual result that the process itself is condemned, while the real fault lies with the operator. We will now assume that the negative is ready for the actual intensify- ing processes, of which we have a considerable number to choose from ; and in this connexion it is instructive and amusing to note how one pro- cess is strongly advocated in one text-book, while the very next book you pick up as strongly deprecates it. No wonder, then, that the mind of the beginner is as badly fogged as perchance liis plate may be. Various Processes. For our present purpose we may divide these intensification prooesMS into three divisions, i.e. : — 1. — The image is first bleached by the application of a certain chemioal, while another chemical is employed to darken it again, producing greater density. '2. — The image is darkened by the application of certain chemioals witlwul previous bleaching. 218 THE BRITISH JOURNAL OF PHOTOGRAPHY. [April 7, 1893 3. The image, after being first bleached, is treated after the manner of an exposed but undeveloped plate. This is called intensification by redevelopment. In the first case, in which bleaching precedes the darkening of the image, the bleaching chemical perhaps most generally employed is mercuric chloride. We take Mercuric chloride 100 grains. Potassium bromide 100 „ Distilled water 10 ounces. Or— Mercuric chloride 5 parts. Pure hydrochloric acid 1 part. Distilled water 100 parts. Dissolve and filter if necessary, as any undissolved particles of the mer- curic salt would be liable to produce spots on the negative. Into this solution place the negative, previously well washed (or soaked) and freed from hypo, until it is bleached right through, and appears of a white or greyish-white colour on both sides ; it is then again thoroughly washed, and is now ready for the darkening solution. In this process the following reaction occurs : — Ago + 2HgCl2 = 2AgCl + HgaCU. Now, there are several methods employed to darken the image. We propose to take three, and refer to them in the order of the effect they produce. (n) If we have a fairly good negative, which is, nevertheless, somewhat thin and produces a flat print, we may introduce the necessary sparkle by using sodium sulphate as the darkening chemical. If the bleached and thoroughly washed negative be placed in a ten per cent, solution of sodium sulphite, acidulated with citric acid till it is darkened throxnjh, again washed, and dried, we shall attain our end. The reaction in this case is as follows : — HgjCl.^ -t- Na„SO., + H.,0 = 2Hg + Na^SOj -I- 2 HCl. Should the density not be considered suiScient, the bleaching and darkening with sulphite may be done a second or even a third time. (6) A more pronounced effect is produced by the employment of am- monia, and this chemical was very generally used, and is so still to a great extent. The bleached and washed negative is immersed in a \oeak solution of ammonia, i.e. about ten minims of the '880 solution to one ounce of distilled water, till it is darkened right through, and then washed again and dried. The reaction here being — Hg.Cl, H- 2NH3 = NH,HgXl -f NHjCl, the dark substance, NHoHgjCI, being dimercurousamraonium chloride. (c) The third method certainly gives very decided results, but with regard to it authorities differ. For instance. Captain Abuey has great faith in it ; Mr. Bothamley says the only drawback is in the use of the highly poisonous potassium cyanide ; Professor Meldola does not raise any objection to it ; but Mr. Chapman Jones says this formula has been proved to be unreliable, and there is no need ever to use such a process. For ourselves, all we can say is, that negatives intensified by it (carefully, of course) some five years ago show no sign of change. Putting difference aside for the moment, the process is as follows: — The bleached and waslied negative is immersed in a solution made thus — No. 1. Silver nitrate 100 grains. Distilled water 10 ounces. No. 2. Cyanide of potassium 100 grains. Distilled water 1 ounce. Dissolve. Add 2 to 1 gradually, and with stirring, till the precipitate first formed is nearly but not quite dissolved, as it is very essential not to have any excess of the cyanide, otherwise after intensification a weaken- ing action ensues, the same result obtaining if the negative is left too long in this solution of potassio-silver cyanide. The reaction in this case is somewhat complex, but may be as follows : — Hg„ CI2 -f 2AgK (CN)„ = Ag„ 4- 2Hg (CN)o -f 2KC1. These comprise the process of mercurial intensification so far as previous bleaching is concerned ; but those who have not already done 80 we would recommend to carefully study the paper by Chapman Jones in The British Jouhnal of Photography for February 3, 1893, p. 70, and in I'hotography for March 9, 1893, p. 146. NON-BLEACHING PROCESSES. We pass now to the second division of our subject, i.e., intensification vrithout previous bleaching, and for this purpose several chemicals are used, e.g., lead, uranium, gold, platinum, biniodide mercury, and a solution made by the Platinotype Company called the " Perfect Intensifier." In using lead several precautions have to be taken, and as it is a troublesome process, and is, moreover, liable to cause fog, it is but seldom Med. Its chemistry depends on the formation of the ferrocyanide of lead and silver, by reduction of the ferricyanide by metallic silver when a negative is treated with the following : — Lead nitrate 20 grains. Potassium ferricyanide (clean) 30 ,, Distilled water 1 ounce. Dissolve, filter, and acidulate with acetic acid. But, as the ferro- cyanide of lead and silver is white, it has to be blackened, after very thorough washing, with a dilute solution of ammonium sulphide, the first reaction being as follows : — 2 Ago -f 2 Pbs Fe„ (CN)., = Ag^ Fe (CN)^ + 3 Pb„ Fe (CN)g, the white ferrocyanides afterwards becoming the black sulphides. Instead of the ammonium sulphide, which is a very nauseous smelUng body, and not an advisable adjunct to a dark room, one of the potassium chromates may be used, in which case we obtain, instead of the black colour, a red one if the dichromate is employed, and a yellow one if the chromate is used. With the uranium intensifier an analogous action takes place, only that, as the uranie ferrocyanide is of a dark brown or chocolate colour, the subsequent application of a darkening agent is in this case un- necessary. The solutions suitable for the purpose are those now commonly em- ployed for producing warm tones on bromide paper, and are as follows : — No. 1. Uranium nitrate 20 grains. Acetic acid J ounce. Water up to 10 ounces. Dissolve. No. 2. Potassium ferricyanide (clean) 20 grains. Acetic acid i ounce. Water up to 10 ounces. Dissolve. Mix these two solutions in equal proportions, and let the very thoroughly washed negative soak in it till the desired colour is attained. Should the action go on too far, a careful application of a weak solution of ammonium carbonate will weaken it, care being taken not to use a strong solution, or allow it to act too long, or the image may disappear altogether. The next intensifier is simplicity itself. A solution is carefully pre- pared as follows : — Mercuric chloride 1 drachm. Potassic iodide 3 drachms. Distilled water 12 ounces. Dissolve. The quantity of iodide being just exactly sufficient to redissolve the bril- liant scarlet precipitate first thrown down. Into this solution tho nega- tive, first well soaked, is placed until the desired effect is attained, after which it is well washed. Objections, it is true, have been urged against this method, in that the image resulting from its use is, or may be, sub- sequently affected by the action of liglit. Similar objections have been raised in regard to the uranium process, hut we believe the supposed effects have been, in both oases, exaggerated. In the case of gold and platinum the change is of the simplest character, one or other of these metals being substituted for the original silver, according to the following equations : — Gold 3Ag„-f2AuCl3 = Au.,-f6AgCl Platinum . . .2Ag., -f PtCl^ = Pt 4- 4AgCl The last intensifier in the second division is the " Perfect Intensifier" of the Platinotype Company ; the composition of this is, of course, a secret, but Captain Abney states that it contains mercuric chloride and a salt of platinum. We can speak from actual experience of the excellence of this intensifier, and also as to the easy and cleanly way in which it can be used. The process is simplicity itself. The first thing to do is to soak the plate in alum solution acidulated with hydrochloric acid, for the purpose, as previously explained, of removing all traces of hypo. Wash well, and immerse in the intensifier, somewhat diluted with water, untH the desired effect is obtained. The action, quoting Captain Abney again, is gradual and effective, and seems to be unaltered by time. Bedevelopment Pbocesses. We now come to the third division of our subject, i.e., intensification by redevelopment. In this, as in all previous cases, the first step con- sists in the thorough removal of all traces of hypo by means of the acidulated solution of alum and thorough washing. The negative is then bleached in an aqueous solution, cold and saturated, of mercuric chloride, to each ounce of which two or three minims of strong hydrochloric acid have been added (this is preferable to employing a solution of mercuric chloride with potassic bromide or ammonium chloride, as is frequently done). When thoroughly bleached and well waslied, the negative may be developed after the manner of a newly exposed plate by most of the developers in common use. We have not had time to try them all, but may say that amidol appears to give a alight increase of density, is clean April 7, 1893] ;HE BRITISH JOURNAL OF PHOTOGRAPHY. 219 in use, and gives a clear and quick-printing negative. Hydroqninone gives greater density, is also easy and clean to use, and produces a clear, good printing negative. In one case in which we tried it, and acci- dentally left the negative in too long, we got the orange hydroquinone stain, exactly as would have happened to a recently exposed and newly developed plate. But pel haps the best method is that of the ferrous-oxalate develop- ment, which is strongly recommended by Professor Meldola, Chapman JoneH. and others. In the first jjlace it is simple, and then again a con- siderable increase of density is obtained, because all the silver and mercury present in the tilm is left behind in the metallic state; and, lastly, like the sodium -sulphite method, it can be repeated over and over again till the necessary opacity is obtained. The solution used should be one part of the saturated solution of Jerrons sulphate to six parts of the saturated solution of potassium oxalate, and it is essential that both solutions should be acid. Sulphuric, acetic, citric, or oxalic acid may be employed for this purpose, and three or lour parts of water. No bromide is required. The previously bleached negative is allowed to soak in this till the image is blackened right through to the back, and is then well washed. It is desirable that the first washing waters should be acidified with hydr' "chloric or acetic acid (as is done in developing bromide paper) to prevent the precipitation of any iron salt or lime from the water. The reaction which takes place here may be represented by the follow- ing equations : — silver Perrons Pohassiam Ferric Potassium Clilorirto. Oxalatu. Oxalate. Silver. Oialatc. Cliloridu. 1.— 2AgCl -i- 2FeC.jOj -h KX.jOj = Agj + FejlC^Oj)., -f 2 KCl. Mercai-ou3 FMrrous Pota^siam Ferric Pot.assiam Cbloritlo. Oualata. Olalite. Mercury. Oxalate. Chloride. 2.— HgsClo + 2 FeCjO^ + KjC.,Oj = 2 Hg -f Fe. (G,0^).^ + 2 KCl. We have thus endeavoured, so far as the time at our disposal will lUow, to pass in somewhat hurried review some of the principal pro- cesses employed in the intensification of negatives, and to indicate the chemical changes involved in these processes, and it is in such work as this that a knowledge of chemistry comes in useful, for the purpose of teaching us not only what to do but why we do it, and to this end we hope the paper we have had the honour and pleasure of laying before you may have contributed. J. H. Balcock, F.C.S. ♦ COPYING ENGRAVINGS AND DEAWINQS. Before the West London Photographic Society, on March 28, Mr. H. Peal, President of the Ealing Photographic Society, gave a lecture on Copying Emjravings and Draitiiigs. As requisites, he recom- mended daylight, preferably a top light, including a wide angle of sky, and appliances specially arranged for the purpose. Tiie lecturer described the apparatus employed by himself in copying engravings in books, con- sisting of a baseboard of bos-girder form with sliding carrier for the camera, and an adjustable frame to hold the book or engraving. He advocated the careful ruling of sets of lines in rectangles upon the ground-glass screen of the camera to ensure facility in focussing. The camera front was raised and lowered by the turning of a disc mounted eccentrically. Coming to the method of working, the lecturer stated that the engraving must be centered with the lens, then focussed, and the final adjustment given. He used small stops, ranging from ./'-ll to /-22, to obtain due sliai-pness. Mentioning the exclusive employment by professional photographers of wet collodion for copying, he claimed equally good re.sults with less trouble from dry plates, such as the Mawson photo-mechanical plate. He found no advantage in backing the plates, but he impressed his hearers with' the necessity of carefully dusting them, and of excluding dost from the dark slides. For regulating exposure, he used the Watkins meter. For reference, he marked all negatives with a series number, a snbject number (in relation the Watkins meter), and an initial to indi- cate the developer used. After mentioning that he employed his nega- ti^ea for the double purpose of producing prints and making lantern slides, the lecturer described a convenient apparatus for the latter pur- pose, in which the top light was reflected through the negative by a ground opal glass plate. An ingenious arrangement of cams was em- ployed for centering and holding the plate in the camera. For development, the new developer, amidol, had many advantages, notably its quickness of action, cleanliness, and power of developing several plates in rotation, whilst it enabled the photographer to do with one-third of the usual exposure, and the developing dish required no I rocking. The formula was — Amidol 4 grains. Sulphite of soda 45 „ Bromide of potassium ^ grain. Water 1 ounce. The lecturerer developed two plates with this solution, under somewhat adverse conditions, with complete success. ©ut IBUitotial CTatle. DlF. I'hotokrbamik. Uj- JuLiOB KrOoer and Jacob Hoskii. Vienna, Pustb, and Liepiifr : A. Hartlebenn. This little work treats exhaustively of burnt-in pictures on porcelain, glass, itc, giving formulic and working details of sutiicient fulnesi and clearness for the ordinary photographer to take up this beautiful branch of photography with successful results. It is fully illustrated. Mkssbs. Tucs. Illingwobtu & Co., of Willosden Junction, have sent us their trade price list of printing, enlarging, finishing, framing, &c. The growth of Messrs. Iliingworth's business is a testimonial to the excellence of their work. Wb have received from Mr. G. V. Oartland, photographer, of Windsor, a flashlight photograph taken at midnight after the recent performance of liecket, before the Queen and Court, by Mr. Irving and his com- pany. The scene represents the four knights and Rosamund gathered round the body of the murdered archbishop. The photograph is a fine piece of work. Mn. J. R. Goxz, of 10, Buckingham-street, Strand, has submitted to us samples of Iris diaphragms which can be made to any size desired within limits, and to any possible aperture, and can be adapted to the lens without the tube being cut. Tlie novelty Mr. (jotz claims is the adoption of vulcanite for the blades, which, for damp climates, should be an advantage. These Iris diaphragms are neatly made and work easily and smoothly. Mawson & Swan's Exposcbb Note-book. Wb have received the latest issue of Messrs. Mawson & .Swan's ^.r- poaure Note-book. Besides useful hints on exposure and spaces for recording exposures given, a variety of formulie and suggestions that would be serviceable in development and other operations are included. Habbison & Sons, Leeds, send us an illustrated sheet showing their new form of head-rests, which, by comparison with their original stands, seem much lighter and in various forms, some for standing on the floor, others for attaching to the back of a chair. Several of them have also supports for the back of the subject. The Weeks & Brill Co., photo-engravers, of 702, Chestnut-street, Philadelphia, have forwarded us several examples of their copper half-tone process. The reproductions, which are chiefly of well-known pictures, are charming m their softness and gradation, and are, besides, extremely well printed. Antho.vy's Internaiionat Annual contains more than the usual number of really fine photographs and engravings. The frontispiece is a lovely portrait by Dana ; others are by Zabriskie, Dr. P. H. Mason, Romyn Hitchcock, John G. Bullock, Horace Gridley, Husnik, J. T. Bedford, Pach Bros., G. W. Wundram, W. A. French, and others. The literary matter is of the usual class. RECENT PATENTS. APPLICATIONS FOR PATENTS. No. 5922. — " Iruprovetiients in Apparatus for Separating .ind Manipulating Plates, Cards, or Films, primirily applicable to Plates, Films, 4c., in Photographic Cameras." H. G. M. Convbe.vue. — Dated March '20, 1893. No. 5932.— "An Improvement in the Manufacture of Photographic Plates." 0. Magkkstkdt. —Z>a(e«<«<< Marck 21, 1893. No. 5894. — " Iniprovemeuts in. or appertaining to, the ExiHwing Devices 6f Hand Cameras or tue like." C. CoVbxtby. — Dated March 21, 1893. No. 6335. — "Improved Construction of Tripod Framing for Pbotograpbic Cameras, Music and Reading Desks." J. H. Rosomas.— Ai(«i March 24, 1893. 220 THE BRITISH JOURNAL OF PHOTOGRAPHY. [April 7, 1893 SPECIFICATIONS PUBLISHED. 1892. No. 5756. — " Photographic Dark Slides." Kirby. No. 8316. — "Photographic Plate-holder." Scott. No. 8324. — " Photographic Cameras." Bell. No. 8646. — "Photographic Cameras." Estcodrt. No. 8659. — " Photographic Cameras." Edwards. No. 10,353.— "Photography." Maeoniez. PATENTS COMPLETED. Improvements in Means tor Obtatninq Photographic Images. (Communicated by Aiigiiste Luniiere and Louis Lumiere, 21, Rue St. Victor, Lyon MontplaLsir, France.) No. 5892. Claude Kennedy Mills, 23, Southampton-buildings, Middlesex.— /'cfcrwary 25, 1893. In treatint; alkaline manganates or permangan.ites with acids, and more par- ticularly ■with organic acids, such as tartaric acid, citric acid, o-talic acid, l.ictic acid, &c., the communicators have succeeded in obtaining salts of sesqnioxide, or of binoxide of manganese, the greater number of which have been incapable of preparation hitherto. These manganic salts are sensible to light, and under its influence are reduced to the condition of manganous salts. The invention consists in the application of this property to the obtaining of photographic images by a process of which the following is a description :^ The salts of sesquioxide and of binoxide of manganese, employed alone or combined with reducing substances, or with bodies which increase their sensi- tivity, are reducejEJ» MEETINGS OP SOCIETIES FOR NEXT WEEK. Date of Meeting. April 10 .. 10... 10... 10... 10... 10... 10... 10... 11... 11... 11 ., 11... 11.. 11.. 11... 11.. 11.. 12.. 12.. 12.. 12.. 12.. 12.. 12.. 13.. 13.. 13.. 13.. 13. 13.. 13.. 13.. U.. U.. U.. U.. u.. 14.. 11. 14.. 15.. NRme of Sooiety. Camera Club Darlington Dundee Amateur Lantern Society Norfolk and Norwich North Middlesex Putney Richmond Birmingham Photo. Society Derby Great Britain Hackney MancheBter Amateur Newcastle-on-Tyne&N.Conntieg Paisley Roche.'iter Stockton Ipswich - Leicester and, Leicestershire Leytoubtone Munster Photographic Club , Sonthpoi-t , Stockpoi-t Birkenhead Photo, Asso Camera Club , Cheltenham Glossop Dale Hull London and Provincial , North Kent , Oldham Bristol and YTost of England Cardiff Croydon Microscopical Halifax Camera Club Holborn Ireland Maidstone West London Hull Place of Meeting. Charing Cross-road, W.C. Trevelyan Hotel, Darlington. Asso. Stndio, Nethergate, Dundee. 20, Haiiover-sqnare. Bell Hotel, Norwich. Jubilee House, Horiisey-road, ?J. Boys' CTymua.ginm,Charlwood-roftcl. Greyhound Hotel. Ctnb Room, Colonnade Hotel. Smith's Ecstaurant, Victoria-sl. 50, Great Russell.st. Bloomsbiiry, 206, Mare-street, Hackney. Lectnre Hall, Athena3um. Central Exchange Art Gallery. 9, Gauze-street, Pai.-.ley. Matbelhatical School, Rochester. Mason's Court, Higrh-street. Art Gallery, Ipswich. Mayor's Parlour, Old Town Hall. The Assembly Rooms, Hiph-road. School of Art, Nelson-plaoe, Cork. Anderton'3 Hotel, Fleet-street.E.C. The Stndio, 16, Cambridgo-ai-ciidt. Mechanics' Institute, Stockport. Y.M.C.A., Grange-rd., Birkenhead. Charing Cross-road, W.C. 71, Prospect-street, Hull. Champion Hotel, 15, Aldersgate-st. Gravesend. The Lyceum, Union-st., Oldham. Rooms, 28, Berkeley-sq., Bristol. Public Hall, George-street, Croydoi: Rooms, 15, Dawson-street, DubllB. ** The Palace," Maidstone. Ohiswick School of Art. Chiflwicfc^ 71, Prospect-street, Hull. I April 7, 1893J THE BRITISH JOURNAL OF PHOTOGRAPH V. 221 PHOTOOUAPHIC SOCIETY OF GREAT BRITAIN. March 28,— Technical MeetinK,— Mr. J. Spiller (Vice-President) in the chair. Platinotyi-k Printino. Mr. F. Hollyer, who was to have given a demonstration of platinotype printinc, was unable to be present on account of illness. In his absence a short discussion on the subject took place, opened by Mr. H. A. I.AwntANOE, who a-slted how to prevent objectionable browo tones when printing from a hanl noRative ? Mr. CHAi'MAS .loNEs said he usually found clear glass give good blacks. Mr. K. \V. Paufitt had Iweu informed that the brown tones complained of were e. Mr. L. W.vunkiike .said lie had tried platinum paper by means of his sensi- tometer, and found he could see the gradations a great deal better than on silver paper. He had fouml the same result with iron paper. The Chaiuman asked wliat were the advantages in tlie new cold process over the hot, lookini; ivt the splendid results the latter gave. -Mr. Wahnkuke .s:ud that it admitted of loeal development. -Mr. Dkbknham also said that, when the prints were successful, a finer range of tone could be obtained. A}>ropos of platinum-toned prints, the Chairman said that, in order to ascertain whether a print was in platinum alone or was a platinnm-toned silver print, the application of a solution of potassium cyanide would decide the point. The cyanide would attack the toned print, and not the pure platinum print. After further discussion on the subject, the evening concluded with a display of lantern slides sent by the Leeds Photographic Society, an affiliated Society. LONDON AND PROVINCIAL PHOTOGRAPHIC ASSOCIATION. Mabch 30,— Mr. J. S. Teape in the chair. ' The Affili.\tios Scheme. I The Hos. Secretary read a letter from the Photographic Society of Great Britain, stating that under the new rules of the Society members of affiliated societies wlio had been members of those societies for not less than two years were eligible for election to the Photographic Society of Great Britain on the nomination of the secretaries of their own societies and without entrance fee. In reply to a question from the bo.x asking for methods of getting clouds on \ the same plate as tlie landscape, Mr. R. Beckett said that brushing the sky portion of the picture over with a solution of bromide had been recommended. Another plan was to start development with a very small proportion of pyro, in order to get the image out all over tlio plate belbre obtaining density. The Sandeii. Plates. Mr. S. Hkrhert Fry delivered .in address on The Sani1e.ll Multiple-coated Plates. [The paper will appear in a future number.] In illustration of points in his address, Mr. Fry showed a number of negatives and prints by Mr. Sanilell, and jmiiited out that although some of them were taken in strong ranlight soft results were obtained. The rapidity of the upper film was evidenced by several hand-camera negatives which were shown. Having described the nature of the double and triple films, Mr. Fry went on to speak of development, and said that, although the makers recommended eikonogen- hydroquinone, experience hail shown that pyro was suitable. For over- exposure development should be tentative. Various claims had been made on beoalf of the plates, namely, that they were suitable for instantaneous work and Interiors, that they provided a cure for halation, that they gave better and rounder images with better " aerial perspective " than ordinary plates, and ' " V were specially useful for beginners. Having dealt fully with each of irns, Mr. P'ry concluded by advising users of the plates not to resort . Mr.'VV. E. Debenham observed that Mr. Fry had said that the use of the ndell plates would enalde one to obtain a larger range of gradation in a ■qih, andhad pointed out that, although .some of the pictures shown .■■n in sunshine, the brightly lighted parts appeared as well lighted as ' iphs taken of subjects where there was no sunshine. He (Mr. jeiiliam) regarded these as extremely valuable feature.s. It had long Ijeen veproach to photography that no method would give a full range of grada- !i, but in the examples before them they certainly got a much greater nroach to it. As to the claim that this form of plate materially prevented ■ evil of halation, it wxs a point the importance of which he was fully alive Tliey must all recognise that of the pictures sent to the most recent hibitiona a good many had suffered terribly from that evil. Tliereforo, ything which tended to show photographers how much better their work ,'ht be was exceedingly useful. How few pictures in an exhibition did we ■ where the ffradation in bright sunshine beats that seen in the examples >wn, particularly in the picture of the Queen's vinery ? If the statements as Sweater range of grailation and freedom from halation are borne out by 1 eated and carefid trial and experience, as they appear to have been home • in the specimens shown, photograi)hers would learn so much that they )uld no longer be content to send to the next exhibition photographs lelective in technical qualities. I Mr. Sarceant said that a day or two before he hail exposed fonr of homas's plates on the interior of a first-floor room in the Adelphi, but had not obtained the-best resnlts. He had tried again, using Sandell pUtea, and had obtaine I can assure him not Jii-e per cent. are. Are there no English photographers in "Bonny Scotland?" It may have been a Welshman who served him the scurvy trick, but to apply the tar-brush to the xclwlc borderland of Wales is a bit unjust. There are "black sheep " in most lands — Mr. Power happened to find one ; but surely, having the man's address, a remedy lies in Mr. Power's hands, if it's " worth the candle." — I am, yours, &c., J. Horton. 26, Caroline-street, Cardiff. THE CONVENTION SLIDES LOSTi To the Editoe. Sir, — May I ask you to give prominence to the fact that the circulating set of slides, issued by the Devon and Cornwall Camera Club in con- nexion with the forthcoming meeting of the Convention, has been lost in transit ? As I cannot recover any trace of them to the present, I am reluctantly compelled to provisionally cancel their engagements, but will put them on the road again as soon as I recover them, and will arrange fresh dates for those Societies that have been disappointed. To the present I have absolutely no information as to their where- abouts, and can only express my regret to all who have been disappointed. — I am, yours, Ac, B. Hansford Worth, Hon. Secretary. 42, George-street, Plymouth, March 28, 1893. "A HARD CASE." To the Editor. Sir, — Having passed through, in my early days of photography, the painful experience — or, rather, want of experience — of your correspondent in "A Hard Case," I can sympathise with him much. Let "A. E. S." take courage from the following: — After three years' apprenticeship, which meant, in my case, a knowledge of silver printing and the art of mounting — and but little else practical photography except that gained in my badfc garden — I found myself expected to take a " sit." away from home. Not feeling any more confidence in myself than "A. E. S.," I took a place as assistant operator and retoucher, and managed (by hard work) to suit my employer. Leaving there, I next obtained a " sit." as operator and retoucher in a busy seaport town, and practised on the sailors, &c. ; after nine months of that, during which period I had won half the battle, viz., gained confidence, I a^^ain sought pastures new, and obtained an appointment in a good-class business as operator and retoucher, which shortly resulted in my being made manager. Therefore; my advice to " A. E. S." is to' get a place in a cheap-class business first, and quietly work his way " up," and I feel sure he will soon reach his level — I am, yonrs, &o., Masaoeb. March 28, 1893. icxcftangc Column. \* No charge ii tnad^ Jot inserting Exchanges of Apparatus in this column ; but none toiU he inaerted unless the article wanted is definiteUj stated. Those who specif y their requirements as *^ anything useful" will ther^ore understand the reason of their non-appearance. The full name if the advertiser must in all cases be given for publication^ otherwise the I^xchanges wilt not be inserted^ Will exchange whole-plato camera with three-fold stand for a cushios •afet7.<~ Address, G. Claukk, Grove^place. Saffron Waldea. Wanted, exterior background, in (jrood condition, in exchange for a fijie-t«necl mandoline.— Address, W. J. Richard, Photogtaphcr, Fore-street^ Collingtoiit Cornwall, 12x10 camera, new, all movoments, in exchange for good hand camera ; aUo good carte lens, exchange for whole-plate wide-angle lens.— Address, W. G. Mabtih, 115, High-street, Merthyr Tydfil. Will exchange a portrait leu« byLerebours (cabinet), a fine vi^oiotttidSxG background and buruislier, fur whole-plate portrait lens. — Address, R. Urowm, Chateau Studio* Boulevard, Weston-super-Mare. Wanted, set of Haddon Hall steps ; offered, in exchan^, Dallmeyer 15x 12 lena, good as now, ia leather case, or a midget camera for taking six on a half-plat^, with ftix portrait lenses.— Address, A. Debbnuam, 28, Unton-street, Ryde, Isle of Wight. Will exchange vol. xxsix. and Nos. IftlS to 1651. clean, unbound, Tus British JOUENAX OF Photogiiaphy, and vol. liii. EntiliKh Mechanic (Hanover on " Construc- tion of MicrOBOope"), unbound, for Thornton -Pickard time and instantaneoas shutter, or one of good make, size of leuF-hood one and a half inches.— Address^ W. H. NicaoLSoai, 44, Windsor-street, Brighton. EncfUJCtjj to ©orresponticnts. „* All matters intended for the text portion of this JouBNAL, includinff Sueries and Exchanges, must he addressed to ''The Editor, The British ODRNAL OF Photography," 2, York-street, Covent Garden, London. In- attention to this emures delay. ,* Correspondents are informed that we cannot undertake to ansxcer com- municalions through the post. \* Communications relating to Advertisements and general business affairs should be addressed to Messrs. Hknry Gkeknwood U Co., 2, rork-streei Covent Garden, London. Photographs Registered : John Stuart, Glaepow.— Pour photograT^hs of the Rev. Adam Cletjlicm Welchf lielen&biirgh. Charles Walker Clarke, Devizes.— Pho(ojrap7i of a dratcing of the ifarket-plote, Devizes, in the olden time. Francis Hoare, Cirencestor. — Photograph of a collection of enlarged photograjths at the Cirencester Industrial and Art Exhibition, Apnl 3, 1893. O. Watmongh Webster, Chester.— Photograph of the (^ictier Beagles, xcith groupof people without tli. Master; also a photograph including the Mailer. W. BiKRELl Received; thanks. F. C. Green (Chihuahua). — Received and forwarded. P. Bebbisgtox.— Write to Mr. T. .Samuels, Linden House, Hadley, Bamet. J. Austin.— 1. Rives paper is mostly used. 2. There would not be any copy- right in such prints. F. B.— 1. You will have to pay duty on taking English plates into the States. 2. Yes, ii X 3;J is an American size. OuVRiBR. — We cannot say whether you have a legal remedy ; we should recommend you to consult a solicitor on the point. Herr Richard Leo (Paulinenstrasse, 48, Stuttgart).— Mr. Gambier Bolton's address is. The Camera Club, Charing Cross-road, W.C. Dial (Glasgow).— In our volume for 1891 you wUI find a series of articles on Bumt-in Enamels, which will give you the necessary information. A Russian Reader.— The apparatus named is excellent The makers would no doubt adapt the shutter to the camera front. A larger front coiUd, of course, be made to take it. B. F. — The formula will do very well. Use a gelatine similar to that em- ployed for dry plates, say, Heinrich's. The paper must be used the day it is sensitised. In cool weather it will sometimes keep till the following day. W. A. M. — If the lens is so firmly fixed in the flange that it defies the oniinary method of unscrewing it, run a little jiaraffin oil round the thread from the inside aud allow it to souk for an hour or two. This treatment will generally enable the lens to be unscrewed witli ease. C. R. — If the lens is not in focus when it is set according to the scale on the mount, it is clear that the scale is in error. It may be that the camera is not the right one for that particular lens. Call the attention of the manu- factiu'ers to the matter. They can easily rectify it. S4 THE BRITISH JOURNAL OF PHOTOGRAPH 1. [AprU 7, 1893 Medal. — The photographs in question were not taken direct from the coins. They were taken from casts in plaster of Paris specially made for the purpose. It is more than probable that the plaster was tinted .so as to be more amenable to the plate ; anyhow, that is the usual method. C. Wade.— The price charged between plate glass and sheet glass, for the frame for the enlargement, is by no means "extortionate." The price of plate glass is about twelve times that of sheet glass, and as there is ten square feet of it, you can judge for yourself as to the reasonableness of the charge. W. Kersh.\w.— The pictures are a little flat, from the lighting. There is evidently too much front to]i light. We .should advise you to have the side light in the studio made larger. That will enalile you to obtain better results. A longer exposure would have been beneficial in the examples forwarded, P. Kellt. — There is nothing in the picture to indicate that the lens is in any way faulty. But as you say the picture was taken with the smallest stop, it is scarcely a fair criterion', for a lens must be very inferior indeed that will not take a fairly good picture with a very small aperture. What will the instrument do with its full opening ! B. A. Thomas asks how to ascertain what size condenser is required for enlarging from a given size negative, whether there is any set rule in the matter ? — Measure the diagonal of the negative, and whatever that may be is the diameter of the condenser that is necessary for the work. It is always well to have it a quarter or halt an inch larger, to allow for any little mar- ginal defects. D. Campbell asks if it is possible to make a mi.xture of albumen and gel.atine that will keep good so that it can be used as required. — Yes. The best way will be to beat up the albumen as for preparing albumenised paper, then dissolve the gelatine iu the desired proportion of water, mix, and afterwards add an antiseptic, sach as a little carbolic acid or thymol. When the mixture is again liquefied, it must not be heated beyond the coagulating point of albumen. Warwick says ; " I have sent to two dealers in photographic chemicals for an ounce of cyanide of potassium, and they refuse to supply it, as they, so they say, would incur a heavy penalty by so doing, and refer me to the chemists. On applying to no less than four of them they said they did not keep it. Surely there should be some means of obtaining the material ?" — Cyanide of potassium is prohibited under the Pljarmacy Act to be sold by other than duly qualified pharmaceutical chemists ; but, as the salt is not contained in the pharmacopffia, very few keep it in stock. It may be procured from any pharmaceutical chemist who makes a speciality of photographic chemicals, and there are many about London and the large provincial towns. P. E. C. says : " 1. I should be greatly obliged if you could answer the follow- ing : — I have found, almost immediately after sensitising, my paper is covered with metallic spots, as piece enclosed. Cannot solve the difficulty. 2. Also would you oblige by answering the following : — I work with the chloride of lime toning bath. What is the cause of it not toning rightly after addition of gold 1 I make every precaution not to get the bath in any way mixed up with any chemicals whatever." — 1. Tlie spots are caused by particles of foreign matter floating on the surface of the bath or settling on the paper while it is drying. 2. If the bath is riglitly prepared, it will tone properly. Probably some injurious substance lias contaminated it as in the case of the paper. A. E. & Co. write : " We are desirous of building another glass house to print in, &c., during wet weather, but we wish to erect it in a way so as to be free from all risks of having to pidl it down again by order of the Council. Neither do we want to submit plans, with the accompanying expense, delay, &c., to the district surveyor. Can you help us out of our difficulty ? We are told, by||making it a movable one, we are within the limits. Is this so ?" — No. On the whole, we are inclined to think the best plan will be to consult the district surveyor. The County Council are very particular as to all buildings that are not " fireproof " under the meaning of the Metropolitan Building Act. If the work is done without the offices of the surveyor, the Building Acts had better be obtained, and their conditions duly con- sidered before commencing operations. H. W. L. writes : " Could you give me the cause of the spots on the enclosed print ? This is only one of a number I have had like this the last few days. If I had not fixed them myself, I should have put it down to their not being moved about sufficiently; but I fixed them myself, and kept them moving the whole time, and fixed for about twelve to fifteen minutes, time that I always have given my prints, but have never had this sort of thing before. Tlie only thing I feel it can be put to is this. On the first occasion that tliey appeared I opened a fresh tub of hypo, and I think that some inferior article has been sent me and charged at full price. Do you think it could be cau-sed by the hypo ? I am going to use a fresh sample to-night, when I may be able to draw a better conclusion ; but perhaps you will give me your opinion on the matter." — We have seen very similar effects caused by the use of inferior hyposulphite of soda, but it is impossible to say if that is the case in the present instance. Of course, as a fresh sample is obtained the results by the two kinds can be compared and an opinion formed. X. A. Y. writes as follows : " Last week a monument to a late very popular man in our town was erected in the public cemetery. As soon as it was finished, a rival of mine photographed it, and the following day I also took a photograph of it. Now I have received a lawyer's letter, saying that his client, the other photographer, has made his photograph copyright, and threatens me with legal proceedings if I publish my picture. Can he stop me publi-shing my picture? I have just learnt that the lawyer's letter was not sent from a solicitor, but was wxitten by a friend of his, a solicitor's ■ jlerk. I fancy the whole thing is a bit of bounce, but your opinion will be esteemed." — Our correspondent cannot be prevented from publishing his picture to his heart's content. The first man can only secure copyright in his work, not in the monument itself. With regard to the " lawyer's letter," if this is written in such a way that it comes from a duly qualified solicitor, it should be forwarded to the Incorporated Law Society, who will possibly take action against the writer for penalties. PHOTOonAPHlC CLtTB.— April 12, Members' Open Night. 19, Cold Bath PlaUnotype Experiences. NBvvcASTLE-ojj-Trsne and Nokthern Counties' Photographic Associa- tion.— April 11, Mr. William Parry will read a paper on lU'touchim. London and Provincial Photographic Association. — April 1.3, Paper by Mr. W. D. Welford, The Influence of the Hand Camera. 20, Monthly Lantern Night. Photographic Society of Great Britain. — April 11, Ordinary Meeting, a paper on The International Congresses of Paris, 1889, and of Brussels, 1891, by Mr. Leon Warnerke. Messrs. R. Sutton & Co., of Ludgate-hill, have in the press a new etlition of The Microscope, and Hovj to Use it, by Mr. T. Charters White, M.R.C.8., F.R.M.S. It is illustrated with photo-micrographs by the author. The Forfarshire Photographic Exhibition. — At the request of English exhibitors, the time for entry forms for this Exhibition to be returned has been extended to Tuesday, April 11. The Judges are Messrs. Marshall Wane, Adam Diston, and W. D. Welford. Statu.^rv Portraits.— Mr. C. C. Bradshaw, of 57, Market-street, Man- chester, has been appointed agent for Messrs. G. B. Bradshaw & Co. of Altrincham's method of producing statuary portraits, and is prepared to grant licences to photographers desiring to .adopt it. We are informed th.at Messrs. Mawson & Swan's largely increased trade has rendered it uecessary for them to enlarge the size of their factory. The new buildings are now complete, and in full working order, and have doubled the size of the factory ias compai-ed with this time last year. The firm have pwt down new engines, electrical and other machinery. The Sandell Exhibition.— During the week April 17 to 22 an Exhibition of photographs, chiefly those taken by Mr. Sandell (on "Sandell" plates) during a recent visit to Italy and Switzerland will be on view at 24, Regent- street, S.W. The proceeds are to be handed over by Messrs. R. W. Thomas & Co. to the Photographers' Benevolent Association, a body wliich, we are pleased to notice, has lately been doing such a large amount of good among needy members of the profession that it deserves on this occasion to be widely supported. Admission is by ticket only —Monday, Tuesday, and Thursd.iy, \s. ; Wednesday (special ticket). Is. 6rf. ; Friday and Saturday, Gd. Tickets may be obtaineil of the Hon. Secretary to the Benevolent Association, Mr. H. Snowdeu Wanl, Memorial Buildings, B.C., or at the offices of The British Journal OF Photography, 2, York-street, Covent-garden, W.C. The Free Portrait Scheme.— At Folkestone Quarter Sessions on Wednes- day, George Gould was to have surrendered to bail to answer an indictment charging him with conspiracy with otliers to defraud a large number of persons of various sums of money by means of the free portrait scheme. There were over seventy witnesses iu atteud.ance, many having come from Ireland and Scotland, and the Treasury liad retained Mr. Crump, Q.C., to conduct the prosecutiou. On Gould's name being called, no answer was made, and it was eventually decided to treat the defendant as an absconder. The recognisances of his sureties, two in 200/. each, were ordered to be estreated, and a bench warrant was issued for the arrest of Gould. The sureties stated that the defendant left the town about three weeks ago, and as soon as they learnt of his absence they followed him to Loudon, but failed to discover his where- abouts. Photographers' Benevolent Association.— Meeting of Committee, held iu the rooms of tlie Photographic Society of Great Britain, on Monday, March 27, Mr. A. Mackie iu the chair. — The Secretary reported that he had just secured a permanent situation for an assistant who had received help from the Association at intervals all through the winter. There were five applications for assistance, and three of the applicants attended. In one case a loan amounting to 6/. , and iu another case 'Al., was granted. In the third case, which was a particularly difficult one, owing to the apjilicaut's inability to speak much English, a temporary grant of 10.9. was made, and applicant was referred to a gentleman of hi.s own nationality. The two cases in which the applicants did not appear personally were referred back to the Secretary, with instructions to make further inquiries, and to grant assistance in certain con- tingencies. Messrs. H. D. Miles and G. Fowler Jones were accepted as subscribers, and the Secretary acknowledged special donations 'from the Photographic Review of Reviews charitable fHn5 hours ; 1888, 33-4 hours ; 1889, 48'3 hours ;' 1890, 65'6 hours I 1891,76-3.5 hours; 1892, 69-5 hours; the present year, 116'16 hours ! Such an amount is almost phenomenal, for this record is not the mere total of the sun's appearance, but of the hours it was powerful enough to stamp its mark on the cards of the instru- ment for recording sunshine used in these Gardens. Animal Charcoal. — Few of our readers but have at one time or another attempted to use charcoal for decolourising, as, for example, with shellac varnish. It is not, however, always under- stood that vegetable charcoal, the kind usually purchaseable in the chemists' shops, is of no use for this purpose : animal charcoal must be used. The form in which it is usually called for varies in different countries where the main demand is for purifying sugar. Thus, in Austria, pieces the size of a walnut were used. In Germany the maximum size is a filbert. In France the size varies from that of grains of linseed up to that of a filbert. In England and America it is required almost wholly of the size of millet seed. The decolourising action is explained by one set of authorities as chemical, and by others as purely physical. Another New Process. — It was announced some time ago that the Messrs. Lumiere were experimenting with manganic salts as photographic agents. In our last issue will be found the specification of a patent they have applied for in this country for their process. From that it will be seen that it is not difficult to work, neither ought it to be costly in practice, and it is said that a variety of tones can be obtained. MM. Lumiere's process will, doubtless, quickly receive attention at the hands of experimentalists. Whether silver will ever meet with a formidable rival in manganese or not remains to be seen. Anyhow, the subject is an interesting one, just now that silver printing is apparently entering somewhat on a new phase as regards commercial work, and it should receive consideration. There is one point in connexion with the manganic method that does not add to its simplicity in working, namely, that the prints are not made direct from the negative, but, as in the primuline process, from a transparency. This rather handicaps a printing process, however otherwise excellent. Fading- " Permanent " Prints. — It may seem an anomaly to speak of permanent prints as fading, yet the thing is, in a sense, of every-day occurrence. Collotypes and prints by other photo-mechanical proce.«ses may be classed as permanent, yet a considerable pro- portion of them undergo a very marked change with even a com- paratively short exposure to light. This is not due to the processes themselves, but to the employment of fugitive pigments in the ink, and also to the frequent use of paper tinted with evanescent dyes. We have before us now some enamelled paper supplied by a Conti- nental house for collotype work, which is as deeply coloured, and apparently with the same dye, as the rose-tinted albumen paper, and the colour is equally as fugitive by exposure to light. If these roseate pigments were simply entirely discharged, the prints would often not suffer materially ; but unfortunately they usually leave an unplea- sant, dirty, yellow effect behind. The marked effect of the light on this class of picture is frequently to be seen after a few days' exposure in the shop windows or at railway book-stalls. ItXeasurlng: Flasks. — Every one accustomed to exact work is acquainted with the value of flasks rather than graduated glass measures for accurately measuring liquids. For making pyroxylin, for example, it is not possible to obtain sufficient uniformity in successive products when the required quantity of water is measured with an ordinary graduate ; a flask should always be used, where the liquids are not indeed weighed. In using flasks, there is some time wasted in obtaining the liquid exactly up to the graduation line, and Mr. Alex. F. Reid, in the Chemical yetvs last week, has described a simple and efficient mode of facilitating the operation. It consists of a wooden or indiarubber plug, with a flange to support it, and fitting loosely into the neck of the flask, and of such size that the part of it that goes in the flask has the same volume as the part of the flask above the mark. To use it the flask is filled with water, say, past the graduation mark, and then the stopper dropped in and withdrawn. The surplus water runs out and the right quantity remains. The stopper has a tapered point, to admit of quick insertion and facilitate the running off of the water upon withdrawal. April 14, 189.'5] THE BRITISH JOURNAL OF PHOTOGRAPHY. 227 XienB-ezpoBingr in the Studio. — VVc havo just spoken of, lui a comiiiim Htudio expedient, llie use of an internal shutter for por- trait work. It is true that it is common, hut it is very far from being universal. We have heen in very many studios where this primitive raetliod — by no other less unflattering name can it be called —of exposing the plate by uncapping the lens is still employed. Yet this is very remarkable, the advantages of a shutter with pneu- matic action are so patent. Take, for example, the exposing of a group. The eye of tlie photographer ought never to leave his sub- ject's, yet it is most diflirtih to avoid doing so unless the exposure is made mechanically. Tiio same in taking photographs of young chil- dren; ten minutes may elapse before a single favourable moment arrives, and tlie mere action of raising or moving the hand sufficiently to uncap the lens is enough to upset the child's face. The verdict of experienced workers with wiiom we have discussed this matter is, that a shutter self-setting is the best — one that is always ready for use, and merely requiring a squeeze of the pneumatic ball and a re- lease^to expose and leave set for the next exposure ; also that it is far better for it to work inwde the camera, thus leaving nothing what- ever that can draw the sitter's attention, be he child or adult, while the exposure is proceeding. Photographs on Textile Fabrics.— Seeing that so many photographers are now .seeking for some new or novel style or description of picture, one cannot but feel some little degree of .surprise that the production of photographs on textile fabrics is so much neglected. The thing i.s by no means new, as we saw silver prints on silk, and really good ones too, some five-and-twenty or tliirty years ago. Photographs on fabrics could bo utilised in many ways, especially for decorative purposes. They can be made on a great variety of materials, and by several different processes. A few years ago we were shown a collection of photographs of fans printed on satin by the collotype process that were of very recherche character. Of course, instead of satin, any other fabric could have been employed, and, in place of collotype, p.ny of the other methods of mechanical printing might have been used. Direct prints on fabrics are easily obtained either by silver printing or by the platino- type process. Fabrics ready prepared for both processes were — and, we believe, still are — regular articles of commerce. Then, again, there is the primuline process of Messrs. Green, Cross, & Bevan, which enables pictures, in a great variety of colours and almost any kind of fabric, to be obtained in a veiy simple maimer. With so many methods of production at disposal, there is no reason why this phase of photography should have been so much neglected. A, Precaution for Continental Tourists. — The season is now coming on wlien tourists will be considering their holiday arrangements. Those who propose to travel on the borders of France and Germany will do well to provide themselves with pa.ssports; more particularly is this the case if they are accompanied with photographic impedimenta. Passports are not really necessary for either France or Germany, but we were told at the Foreign Office a short time back that it was advisable for British subjects to be pronded with them when travelling on the frontiers of the two countries. Photographing in the neighbourhood of fortifications on the frontier is strictly for- bidden, even though they are not included in the view, or cannot even be seen from the print. Through ignorance of this rule, foreign visitors have sometimes innocently been subjected to great incon- venience, not to say indignities. It is in such cases as this that the passport is of advantage. The holder of an English Foreign Office passport, duly vised, would at once be acquitted of being a spy by either country. A passport can be obtained for two shillings by application to the Foreign Office on the proper form. When the document is obtained, it is well to get it countersigned at the Consulates of the two countries. Passports, like revolvers, are rarely required when travelling now, but when they are tiiey are generully of great service. The Camera in Anthropologry.— Mr. E. F. im Thurm recently gave a paper on this topic before the Anthropological Society of Great Britain. He points out that, in taking photographs of savages, special care has to be taken to avoid getting them in that "non-natural" state so often characteristic of such pictures. For example, he has seen the same savage native in a town and in the country, and he looked like two different individuals, though hia costume was little more in each case than a yard of tape — literally, a single strip of cloth about a yard long and two or three inches wide. It cannot but be remarked that the lecturer himself did not go about his work in a very workmanlike manner for the end in view. Thus, instead of working a camera with an internal concealed shutter, he, in a description of a very amusing experience, tells us he simply caps and uncaps his lens. '' The first time I tried to photograph a red man was among the mangrove trees. My red-slrinned subject was carefully posed high up on a mangrove foot. He sat quite still while I focussed and drew the shutter. Then, as I took off the cap, with a moan he fell backward off his perch on to the soft sand below him, nor could he by any means be persuaded to prepare himself once more to face the unknown terrors of the camera. A very common thing to happen to foil the efforts of the photographer at the very moment when he has but to withdraw and to replace the cap is for the timid subject suddenly to put up his hand to conceal his face," &c. It is surprising that it never occurred to Mr. im Thurm to adopt a studio expedient now common enough. CBYSTAL PALACE PHOTOGRAPHIC EXHIBITION. The " National " Photographic Exhibition at the Crystal Palace opened on Monday last, April 10, and is advertised to remain on view until the 2yth inst. It is to be regretted that in neither the apparatus section nor that devoted to photographs does the Exhibition redeem tlie character of " National" that has been assigned to it, a result that must undoubtedly create an unfavourable impression in the photographic world, and at least a feeling of surprise among the general public. Taking the photographs first : the responses of exhibitors, although producing on the whole a passable di8play,'eannot be considered at all representative of the present state of photographic art, while as regards the apparatus the exhibits scarcely exceed ten in number, and these betray an unfortunate paucity of novelties, and are, besides, of such meagre extent that the entire con- tents of the stalls might comfortably be placed in a shop of moderate size. The ArpABATUs Sectiox. At four o'clock on Monday afternoon the following was the state of the Apparatus Section :— Messrs. E. & J. Beck, of Cornhill, had a handsome stand showing a series of fine enlargements from negatives taken in the " Frena' hand camera ; Messrs. J. Theobald & Co., of 43, Farringdon- road, an extensive display of optical lanterns, coloured slides, limes, con- densers, stand cameras and stands, hand cameras, and photographic sundries generally. Included among Messrs. Theobald's exhibit is a cheap and ingenious hsuid camera, the "Meteor," in which sheathed films or plates are used, the sheath with the exposed plate being released by a single turn of a screw at the side of the camera, and sliding down an incline into the back of the camera as shown in the cut. The " Meteor " has but two little brass knobs, and the handle to Scarry it by, projecting, and two view finders (which are let in flush witli the body) ; is cloth-covered, has twelve sheaths carrying twelve plates or films, the special lens working with a time and instantaneous shutter inside the camera, and again worked by turning a little brass catch. It can be used for taking views or portraits both vertical and horizontal, and all for 128. 6<2. ! Messrs. D. Noakes & Sons show several serviceable lanterns, cameras, with lathes at work ; Messrs. T. W. Couch & Co., of 11, Bow-lane, a selection of pictures set in a variety of choice frames ; Messrs. Piatt some animated illustrations of Golfing by Mr. Lange ; and a selection from Mr. Sandland's lion, tiger, and buffalo pictures, and his excellent horse picture Unyoking. May we suggest to Mr. Sandland that he is less successful with his composition subjects including the human species than with his animals ? Messrs. S. B. Bolas have some good examples of collotype ; Messrs. Poulton, a selection from their well-known series ; Messrs. Gregory, of the Strand, coloured types of the British army. Mr. W. P. Marsh, of Bognor, has rarely shown better seascapes than those he has here, both small and large. He seems to have studied the sea in nearly all its moods, and the result is a fine collection of wave pieces, all cleverly caught. A blue carbon print, After a Sou' -Wester, is especially good in its realism, and a study of A Breaker noi less so. What soft, evenly lighted work can be produced by flashlight, Mr. E. SUngsby, of Lincoln, shows by several very fine examples. Mr. Douglas Pym's touched and untouched portraiture are both noticeable for their good qualities, aud in Dad's Pipe, a boy in tlu-ee stages of a bout with the paternal calumet, there is considerable quiet humour as well as great photographic merit. We do not like Mr. Pym's Repose, however. This shows a very lightly clad, finely limbed young lady, simulating sleep in a recumbent position, with so little relief in the face that the result is not convincing. Mr. Dresser has a screen filled with his well-known works. Mr. E. M. Stone shows three small views, A Yorkshire Coble, Filey, and On the Thames, with nice sepia tones, sharp, crisp, and well printed, which are certainly amongst the finest tilings of the kind in the Exhibition. Mr. Court Coles's interiors, the Hon. S. Bethel's Shipping at Guernsey (a freely handled picture), and the same gentleman's Clouds, with Mr, T. Scotton's Musselburgh Fishwives and cathedral studies, are safe to hold the attention of even the non-photographic visitor to this part of the display. Examples of statuesque portraits of a high degree of skill are shown April 14, THE BRITISH JOUKNAL OF PHOTOGRAPHY. by Mrs. Prank Holmes, of Bristol. Wo would recommend professional pUotographors to study them. Steathj, two men fishing, and in tlie act of getting a bite, is a clever bit of work by Mr. H. Young, the effect being perfect. Mr. T. M. Brownrigg'B Winter Sunset, Derwentwater, and Morning on the Wey are especially evident in an Exhibition singularly free of impressionistic pictures. Messrs. Alfred Werner Sc Son show a few large portraits of a superior quality, pose and lighting being exceptionally fine. Finally, Mr. Goodwin, of Anerley-road, makes a highly meritorious display of portrait work — indeed, tlio Exhibition is commendably strong in professional portraiture— and Mr. C. F. Treble, of Clapham Junction, besides exhibiting some examples of portraiture by theWelsbach light,which show perfect tone rendering and freedom from harshness, includes a varied collection of large and small portraits of great beauty in his alcove. Mr. Treble's examples in sepia platinotype are remarkably engaging in their compromise between critical sharpness and diffusion ; and, indeed, the exhibit as a whole is a fine one. It should bo mentioned that the Judges only met for the purpose of making awards on Thursday (yesterday), and that wliile the Exhibition is open there will be nightly lantern entertainments. AMERICAN NOTES AND NEWS. The Smartness of the '< Heathen Chinee."— It is pretty evident that the mental or, rather, the moral characteristics of the Celestials in America have not suffered any change since those days when Ah Sin, the gentleman vrhose " smile was so childlike and bland," engaged in the ever-celebrated g&me of euchre -with truthful James and Bill Nye. In May next the Chinese Registration Act comes into force. This necessitates each Chinese labourer in the country presenting himself at the office of the Collector of Inland Revenue with proper vouchers from the Chinese Consul, on which certificates are to he pasted a photograph of the bearer, a dupli- cate of this being returned to him, which he is compelled to show on demand to any United States official as his authority. Here, now comes the smart part of it, for which information we are indebted to Mr. Julius F. Sachse, Editor of the American Journal of Photography. The photographic part of this certificate is in reality the only means by which it can be determined whether the holder is the same indi- vidual to whom it was granted, as the description given would in most cases fit ninety-five out of a hundred Chinamen. But a photo- graphic chemist in Philadelphia has been teaching the Celestials how to produce photographs which, within a few months, would so fade as to fail in the identification of the individual, while the written description would still remain. The authorities are taking steps to circumvent and punish the conspirators. Cleaning- and Photographing- Old Oil Palntlng^s.— A writer in the same journal, who has had experience in copying oil paintings, gives the following as his mode of cleaning old paintings previous to their being photographed :— After dusting, wash the painting by a sponge and rain water, and then sponge over the surface the following : — The white of two eggs, beaten up and cleared, a tablespoonful of glycerine, and half a litre of water. The ohject of adding the glycerine is to prevent the albumen from drying in spots, which would appear dull, and prove of injury to the reproduction. Focal Plane Shutter.— The employment of this class of shutter is strongly advocated in our Philadelphia contemporary. It is constructed in the same way as the Thornton-Pickard shutter, hut its position, instead of being close to the lens, is situated in front of, and as close as practicable to, the sensitive plate. The roller blind composing the shutter has a narrow slot in it, and travels rapidly across the plate. We are personally aware that some bicycle scenes, of exquisite sharpness and well lighted, were taken by Mr. James Inglis, formerly of Montreal, by a metal shutter constructed on this principle, and working at the focal plane. These were exhibited six years ago at one of the London societies. It was estimated that the exposure was about the thousandth of a second. aequlrements for Suoceas.— Mr. Xanthus Smith layii down as conditions of success in the studio or portrait branch of photography, perseverance, good business ability, a large amount of good address and tact, and, highest of all, artistic taate or good judgment in matters of art. The special qualifications for outdoor photography are, in his estimation, good general artistic sense, quick- ness of perception, rapid and sound judgment in selection and timing, this last being necessary to cope with the changes in the conditions of lighting, of subject, and of exposure. Animal Xilfe.- In the portrayal of animal life, Mr. Smith holds the utmost pains should be taken; in tho first place to acquire a knowledge of the poses in which different animals show their good points to the best advantage, the best lighting and accompaniments, chiefly as to background, for the success of a great part of animal photography is marred by carelessness about the background. In addition, great patience and perseverance are required in the manage- ment of animals in photography ; but, when success is attained, we have in refined pictures of handsome animals one of the most interesting phases of the photographic art. SKiss Barnes's Sng-lish Trip. — In the American Amateur Photographer Miss Barnes continues the account of her camera trip in Great Britain, illustrating her paper wdth several views, mainly of archaeological subjects in Yorkshire, such as Fountain's Abbey and Old Remains in the City of York, very nicely phototyped on stout calendered paper. Coincidence or Plag'iarism? — Enowing|the honesty of the American journalists, and their promptness in acknowledging the sources from which their reprint articles are taken, we are the more surprised at Dr. John H. Janeway making himself, in his Index Jterum Pkotoyi-aphie, an exception to this well-recognised rule of courtesy. Interested in seeing what he had to say on the flare-spot or ghost, we read his (?) article on that subject in the last-named serial, and found it to be a reproduction, verb, et lit., of what we published a few years since, without the slightest acknowledgment. While we feel it a compliment to have articles from this journal re- produced by American friends, we must certainly draw the line at such appropriation as that just indicated. DETERMINATION OF PLATE SPEEDS. [London and ProTincial Photographic AsBociation.] Befobk commencing my paper, a few words are necessary to explain the reason of my appearance before you this evening. Those of you who read Thb British Joubnai. of Photography may have noticed that, on January 27 and February 3, there appeared two articles over my signature, headed, "Determination of Plate Speeds.'" Imme- diately following publication, there also appeared a mass of corre- spondence, some of it of a very violent tone, and most of it irrelevant to the question at issue. To tliis correspondence I replied briefly, to the effect that I should abide by my experiments ; and such was my courage of my own opinions that I offered to submit everything to a disinterested jury, and I further offered to repeat any individual ex- periment such jury might select. To this challenge none of my dissentients have responded. It might be thought that, in making such offers, I would be pretty safe, by reason of the disinclination of any of these parties to try conclusions ^vith me, especially when so wide a chasm separates us in the views we hold of the theory involved in the matter ; but, as I was not disposed to allow this subject to rest where it was, it is with full belief that I shall be fairly dealt with at your hands that has prompted me to lay before you an account of my " investigations," accompanied by examples. I thereby constitute the London and Provincial Photo- graphic Association my jury, and I shall be glad if you will accord me a patient hearing. In bringing this subject before you, I am assuming that most S resent will have read my previous remarks in Thr British OURNAL OF Photoguai'HY of January 27 and February 3. In case any have not, I will endeavour shortly to outline them. Messrs. Hubier & Dbiffiki,ds Invkstigations and the Spebds of Plates. You may be aware that some three years ago Messrs. Hurler & Driffield published their " Investigations." Beyond creating some 230 THE BBITISH JOURNAL OF PHOlOaRAPHY. [April 14, 1893 surprise in photographic circles, I am not aware that their remarks produced any further effect than what might have been _ expected from the publication of matter of so distinctly controversial a clia- racter. Many of their conclusions were so totally at variance with the preconceived notions of most photographers, including myself, that, lilje other things, one might have expected the subject would be a nine days' wonder, and then fall into oblivion; but, for reasons best known to themselves, certain manufacturers of dry plates have thought fit to adopt the system introduced by these gentlemen, and have issued boxes of plates marked on the outside with speed numbers in accordance with the method of Messrs. Hurter & DnlEeld. I, like others, have been a purchaser of these plates. Without recapitulating much that has already been published in my previous articles, suffice it, perhaps, to say I think it is beyond controversy that, if we purchase plates bearing speed numbers according to any method or system, we have a right to demand that the goods so sold shall be what they are represented. From the dealers and from the makers direct I purchased many boxes of plates, bearing speed numbers of 37, 80, 95, 100, 135, and 140. I tried a variety of experiments m different ways, to ascertain whether the relative speeds, as indicated on the boxes, were borne out in actual practice, and I finally adopted the method of exposing two competing plates side by side in a stereo- scopic camera. I need not dilate upon the accuracy of this method beyond any other known method of competitive camera comparisons of the sensitiveness of different plates. Supposing the possibility of error, the method I adopted of making dupUcate, and even triplicate, tests, and thereby reversing the positions of the plates, at once serves to expose any error, and enables one to judge with accuracy any difference in results. As you will see bv the examples I will hand round, the subject was one well calculated "to test the rapidity of plates against one another, and very fine shades of extra sensitiveness in one or the other of any given pair of competing plates could be readily observed. I must point out to you where the variations in sensitiveness are chiefly to be detected. The stove you see in the negatives is dead black, and stands within the recess of a dead black gi-ate. "i'ou will detect differences, vrhere it exists, in the sensitiveness by closely examining all around these dark parts, and in the relief ornament of the grate, the horse- shoe form of which is visible in some plates and not in others. Another point for the detection of sensitiveness will be found in the detail, or the absence of it, in the clothing hanging in the corner in the shade of the chimney-breast. When examining each pair of nega- tives, I must ask you to read the explanations written at the foot of each, and also to "bear in mind the conditions involved in producing each pair. Since I mounted these examples, I have gone over them and marked in red ink my estimates of the percentage differences in their sensitiveness, together with other remarks, in accordance with my published list of experiments on pages 69 and 79 of The Bhitish JotjRXAL OF Photography, copies of which are on the table. Messrs. Hurter & Driffield have said that I cannot estimate dif- ferences of ten per cent. If I tell you that in several instances, in order to check my estimates, I gave the additional exposure to the slower plate, and thereby obtained identical negatives, as far as two different emulsions will yield two similarly exposed negatives, I think you must give me credit for knowing what I am talking about ; and I shall leave you to judge of the general accuracy of my estimates, of which a large number are submitted to your inspection. The Method op Development Emploted. Now let me add a few words of explanation of the method of de- velopment employed. 1 have previously stated that the plan on which I proceeded was to give such exposures as would leave me tlie shadows — even the very deepest shadows round the stove — clear up to the end of prolonged development. The plates were developed by the formulae of the manufacturers, and development was, in every instance, carried on until no further detidl would come. Any attempt to ascertain differences of sensitiveness by developing for any arbitrary length of time must, in my opinion, result in unfairness to one or other of the plates under trial, and especially so if they are of different makes. I maintain that by the treatment I adopted can we alone dis- criminate differences of sensitiveness between competitive plates with- out favouring or prejudicing either one or another. If, with a given exposure of identical duration for a pair, one plate shows, under pro- longed development, greater detail in deep shadow, I should certainly say that plate is the more rapid of the two. If I verify this result by making a repeat, or yet a third test, no room for doubt exists. I must point out in connexion with this, that if we expose so as to get a pair of fiillt/ exposed plates, on development the pair, even if of dif- ferent makes and sensitiveness, will frequently appear almost identical, and I must insist that full exposures or over-exposures are no tests whatever of the rapidities of plates. In all experiments of this class 8ome little heed must be given to the thickness or thinness of the coating, which does influence the result, but least of all in those parts the least exposed, viz., in the deepest shadows. No GaUDGB AGAINST IIUBTBE & DeIPFIELD's MbTHOD. Judging from the tone of the correspondence I have alluded to as following my original articles, one might imagine that when I wrote them I had sat down with the deliberate intention of demolishing the Hurter-Driffield theory, or that I had some especial grudge against plates " speeded " in accordance with that method. As a matter of fact, I bad no such idea, and I disclaim any intention other than that of putting to the test of actual use the plates so marked, to ascertain whether they bore out the theory. This they f aUed to do ; and I am left to adopt either of two conclusions : — (a.) If these plates had ever been submitted to examination in an instrument of precision, such as we are led to believe the Hurter- Driffield modification of Bunsen's photometer is, then I say, if the system is right, the plates are wrong, and the examiners either do not understand the system or they have blundered. (4) If, on the other hand, these plates have been accurately examined and "speeded" by the system, then the system is wrong, for the plates most certainly are incorrectly marked, and do not carry out the system. I have already alluded to the tone of the correspondence, I don't know that I should have noticed it but that the damning admissions made by one of the writers affords me the opportunity to expose what is either gross ignorance or a wilful perversion of facts. This brings me to another branch of my subject not previously dealt with. Just let me read you two extracts from letters already published. The first is from a letter in Photoyraphi/, 26th January last, page 63, and is signed " Platemaker." He says : — " So little does the question of daylight versus candle-liglit come into practical effect that Mr. Driffield teUs me that even ortho plates, as far as he is able to observe, are correctly read by the candle for ordinary day- light exposures." The next is from a letter in The British Joitbnal op Photo- graphy, February 10 last, page 94, and is signed by James Cadett. He says: — " I now come to the candle question. It is manifest that, provided that all makes o£ plates obey the same constant in the relative sensitiveness to candle-light and daylight, it does not matter a fig what that constant may be. Do plates obey that constant, generaUy speaking ? All that I can say is this, that, after hundreds of tests, neither Messrs. Hurter & Driffield, Mr. A. Cowan, nor myself, are able to say that plates vary in this respect. Even orthochromatic plates for ordinary landscape work obey the same constant very well, though, of course, it is easy to see that under certain conditions of screen and light such plates would require a different constant." Now, gentlemen, I am not quite so intent upon pointing out to you the strong family likeness that exists in these two letters (which may possibly be the result of accident) as I am anxious to inform you that the statements there made are absolutely incorrect and untrue so far as orthoc,hromatic plates are concerned. Whilst I am sorry that such erroneous dogma should get publicity, I feel compelled to adopt the only course open to me, which is that of giving it a deliberate con- tradiction, and now I am going to prove it to you. Proof to the Contrary. The pair of specimens (mounted on opal glass to make them very easily judged) which I shall place in the Chairman's hands were produced in the following manner. Taking a box of " Ordinary " plates and another of " isochromatic medium" plates, we shall find their rapidities to dayliirht very nearly equal, and these will enable us to make a most conclusive experiment. I cut two plates down the centre, and take half of each to an experiment. I place a simple graded screen in an ordinary printing frame, and put half an " ordinary " plate and half an "isochromatic" plate thereon, and expose briefly to usual daylight at midday. The result of this exposure, developed to completion, will be found on the right hand of the specimen, and is marked "daylight." You will probably agree with me that their sensitiveness to daylight as read by this means will be about two points in favour of the isochromatic plate, viewing the densities as transparencies. I then take the other two halves of these plates, and place them just as before, but instead of daylight I submit them to candle-light. As a matter of fact, the pair at the left hand had ten CM. seconds. You will see that even ten C.M.S. impress the " iso " plate to such an extent as to reveal the last grade of the screen (16) with great force, whilst the " ordinary " plate responds in a remarkably feeble manner. A longer exposure, such as fifteen C.M.S. or twenty C.M.S., AprU 14, 1893] THE BRITISH JOURNAL OF PHOTOGRAPHY. 231 will (five you a bettor reading on the " ordinary " pkte ; but so sensitive are the " iso " plates to candle-light that great density results up to tiie full scale of toe screen, and the comparative reading^ are valueless. As it is, and viewing these results by transmitted light, I think you will allow that there are from ten to twelve points in favour of the " iso " plate, and to verify this the Chairman shall be at liberty to cut the specimens off the opal glass after they have been all round, and then compare the relative gradations. Viewed by reflected light, the difference is even greater. Now, gentlemen, how do you find it? On the one hand look at the two letters of " Platemaker " and Jas. Cadett, and, on the other hand, weigh these experiments ! Please accept my assurances that these experiments have been repeated over and over again, and always with a like result. Do you find that ordinary and isochromatic plates obey the same constant — the candle, or do you think with me that any one who could be rash enough to make such an assertion must surely have forgotten the very raison-d^Hre of isochromatic plates ? If I needed confirmation of the results I place before you, I need but refer vou to an article bearing strongly on this very subject, by Mr. DeSenham, and you will find his experiments recorded on the very same page of The Buitisii Joubnai. of Photogbaphy (page 60) as my own. As this page is before you, please refer to Mr. Debenham's figures. He gives you for camera exposures with day- light, " ordinary " aud " isochromatic instantaneous," equal periods ; but for lamp-light you will see he fixes the rapidity of the " isochro- matic " plate at no less than eiyht times that of the ordinary ! With no intention of either attacking the system nor yet of inter- fering with any man's trade, I repeat that my object has been solely to ascertain whether and how far the theory and the practice of determining the speed of plates would accord, and in the alternative as to whether the theory could bo of any assistance (or otherwise) to practical photography. If time permitted, I should like to have read to you a leader from Photography, signed " A. P.," and dated March 2. As it is, I must content myself with a short excerpt therefrom. Alluding to Messrs. Ilurter & Driffield, the writer says : — " . . . .If they mean that, after all, we can materially control our practical results by controlling the developer and the following opera- tions, tlien no more need be said ; but, with their writings before us, we must say that it is by no means clear what they do mean in the matter." As I have not found that the theory of these gentlemen has been borne out by the plates issued in conformity with their system, I decided to place my findings on record ; hence all this storm, and hence, also, my appearance before you this evening, which I deter- mined upon even if it involved further encounter with my cavillers, or entailed a recital of the tenets of my photographic creed. I trust that the subject may have interested you sufficiently to induce discussion whereby we may gain photographic knowledge, and endeavour to arrive at perfection and the truth. G. F. Williams. NATURALISTIC PHOTOGRAPHY.* And now we will return to the main subject, which I shall lay before you in a series of propositions only, for psychology has not yet become a science in the true sense ; psychological work is merely in the working hypothesis stage, though by no means at the worked-out hypothesis end. Proposition I. — That the material universe may be regarded by us •8 eternal (though varying in aspects), and the fountain-head of all our sensuous impreasions. ProjHMition II. — That accepting the doctrine of evolution the mind has evolved from the merest crude .sensations of the amcBba to the complex and subtle sensations of the master artists of to-day. Proposition III. — That in the course of this evolution there arose the sensation and perception of the beautiful,! and this emotion was followed by acts intended for ornamentation of their persons or homes. Proposition IV. — That from this germ developed the sense of the beautiful, until in civilised man this appreciation of the beautiful may be divided into three steps : — 1. That of sensation. 2. That of perception (intellectual). 3. That of emotion. That these three be three distinct processes, yet they are one — indissoluble. ProjMisition F.— That the appreciation of the beautiful is thus sub- jective, an ideal existing in the minds of men in varying degrees of development ; and that, though Nature (by which the objective world * Concluded from page 213. t According to Darwin this is a fact first noticeable in bu-ds. IS meant) has probably produced at various times exquisite harmonie*, it took man to recognise these as beautiful, and so it has been said the artist is the master of Nature. I'roposition VI. — That, as the nkbvocs system developed, these appreciations became more delicate and subtle, and so a man with a naturally delicate sense of vision gradually purges himself of the coarser emotions, and his perceptions are more purely cerebral acts. A master artist regards first of all by mere acrjuaintance the decora- tive harmony of a picture or natural scene, then by previously acquired knowledge he knows why it is lovely, fit, true in sentiment, and distinfftii, and that knowledge gives way to the emotion of joy, which is expressed physically by his smiling face. That the reverse is the process with the Philistine ; the crude and tawdry appeals first to his emotion, hence the popularity of the senti- mental subject ; of the anecdote ; of " literature in the flat." Proposition VII.— Th&t we have physiological proof that men's sensitiveness varies in degrees of fineness ; thus a virtuoso in flour knows samples grown in different countries by their feel, a virtuoso in wine knows a glass of port taken from near the bottom from one taken from the top of the bottle, and the blind Laura Bridgeman knew purely by touch the clothes of all the inmates of a workhouse. From which it is self-evident that in all persons the boundary of their I appreciation is hard drawn ; in some cases, therefore, fatally limited by their very organization. A man whose vision is not delicate can rieeer see the delicacies of line, colour, and tone patent to a moro delicate nervous organization. Such a limited person is for ever doomed to be outside the pale of tlie pictorial art world, as the man with no ear for music is for ever doomed to be an " outsider " in the musical world. Proposition VIII. — That, as the sense of beauty is a human ideal, this ideal \\'ill vary with individuals and in the individual from day to day, nay, from hour to hour. Indeed, so complex are the brain processes, and so dependent upon each other, that an artist may begin a picture with one ideal and finish it with quite a different ideal. Indeed, it la one of the great difficulties of the artist to keep steadily to his original ideal throughout the work. A glass of wine, a santo- nine powder, may completely change his ideal or power of execution. From which it is plain how delicate a thing is a work of art, how thoroughly personal is every touch in a work worthy the name of art, what a perfect index of the creator's mind. Proposition IX. — That the ideal existing in any given brain at any moment is a complex and refined essence, the result of the man's whole previous life up to date ; wherefore this ideal is no mere re- flection of Nature, but a result of imagination, or the selection from various ideals or parts of ideals ; and thus man may go beyond Nature and conceive things that do not exist in the world— such as the vase, the phonograph. That fine art is the artistic expression of this ideal by a personal method, and that no man is an artist who has the ideal and can see the beautiful if he have not the power of execution as well. Art is therefore achievement. By their results alone are artists to be judged ; as thus a very inferior technician may be a very delicate seer of the beautiful, but the world rightly only gives him credit for his picture— Ai« result— andi if that be poor, if his hand cannot express his ideal, he does not rank highly, nor often does he get credit as a seer. " Art is therefore with the man," as Mr. Wliistler has said. Proposition X. — That Nature sometimes sings in tune, or succeeds in producing glorious and exquisite harmonies, harmonies fully ap- preciated by the seers of the beautiful, for many more may appreciate than can depict; hence the rarity of real artists. Whence also a layman may be a far keener seer than most painters ; but seer and masterly executant is genius itself. Again, that the harmonies of Nature are altogether different from the harmonies of art — are dependent on different phenomena, and that Nature and art are different worlds. That Nature sometimes sings in tune Mr. Whistler himself has allowed, but I submit that it is abso- lutely impossible to reproduce that harmony on a plane surface ; it is a thing by itself, a thing apart; though a number of unphilosophical painters think they do reproduce Nature, but they do not. Here is a very simple proof suggested to me by my friend Mr. Havard Thomas, a sculptor. Let the observer look at a distant landscape behind some reed-stalks in the foreground. The reed-stalks in Nature, under cer- tain conditions, do not blot out any of the background, we see round them, and see the ivhole landscape beyond. In art the reed-stalks would always Uot out part of the background. I think our sense of the third dimension of space or " distance " arose first through this peculiarity of vision. For further and deeper proofs of the utter impossibility of reproducing Nature as we see her I must, in a brief paper like the present, refer you to Professor Hemholtz's Scientijic Lectures, to Mr. Rood's Chromatics, and to our Perspective Drawing and Vision. A careful study of these publications, aided by a few 232 THE BRITISH JOURNAL OF PHOTOORAPHY. [AprU 14, 1893 experiments made for himself, will convince the veriest neophyte that it is impossible to reproduce Nature or make a " mere transcript." Proposition XI. — That in photography we are confronted with a new phenomenon, in that we find some of the results of a machine give true pleasure to master artists which has never hitherto been the case with machine-made works. _ . Proposition X77.— That photography is not art because a machine comes between the man's ideal and Nature, and the result is machine- made, the trapping of a sunbeam. Say the photographer, like the painter, goes to Nature with certain ideals — we will, for illustration's sake, assume that two men have exactly similar ideals of the beautiful (which is, of course, impossible). They go together to Nature, and find a beautiful natural harmony in a lovely stretch of purple sands by the sounding sea. The photogi-apher at once sets up his machine, focusses, and exposes ; but in these very processes his ideal has gone. What results may be beautiful, but it is no more the representation of his ideal, the vision he first saw. It is something else, for the machine imposes certain conditions which were never in the photo- grapher's mind at all. How often has the most experienced of us been disappointed with the photograph of what wtis fine in Nature — fine to our eyes that is, and sometimes ince versa 9 The painter, on the other hand, begins, and if he be an expert each touch helps to his desired or ideal end ; this wavelet is delicately put in, that breaker strongly and broadly, and so on ; everything is done unto one end, and all is certain from the first — whereas the photo- grapher has boxed a maimed and contracted reflection of what he saw. True, it may be a beautiful reflection ; but, after all, it is Nature's drawing, and not the man's. Still such machine-drawn pictures may in certain cases satisfy, or rather harmonise with, the photographer's ideal of beauty, or, indeed, with the master painter's, as does a beautiful natural landscape; and yet, again, the beautiful photograph is not art any more than the natural scene of which it is a reflection. Proposition XIII. — That, though the machine draws the photograph, yet in the production of a photograph there are a few (very few) very limited incalculable elements, as there are in organ-grinding and engine-driving. These are — (1) Selection of view. (2) Selection of lens. (3) Selection of focus. (4) Selection of developer. (5) Selection of printingimethod. These limited incalculable elements give a man a very limited oppor- tunity of blending his materials to his ideal, and though, bv taking ad- vantage of these with knowledge, he may surpass other pliotographers in decorative work, still they are too limited for him to express to any degree of certainty or fulness his ideal; and, since the drawing is mechanical, these few very limited incalculable elements cannot enable a man to express his ideal in anything like the same degree as does a personal art. Indeed, photography is not nearly so personal an art as sailing or rifle shooting, both of which have very little of the mechanical about them and much of the personal. In photography man puts the machine under certain physical con- ditions, and the machine will always (under these same conditions) bring about the same result ; therefore the process is logically mechanical. On the other hand, a personal art is one in which the results would differ again and again under the same physical condi- tions, for the mind would work differently on each so-called " replica " of the original — no artist could paint two pictures e.vacthj alike. A photographer might take fifty views of a subject exactly similar, from which it is self-evident that photographs are not works of art in the sense accepted by artists, though photography may be an art or craft in the old sense of the word art, as surgery is an art ; but such a use of the word " art " aa applied to photography would not satisfy the dilettante, for the word used so would include every photographer as an artist, which is not what the ambitious amateur means at all. Proposition X/F.— That therefore it would be wiser for all photo- graphers to drop the use of the words " art " and " artist " in con- nexion with photography (photography is a science, or hopes to be some day), and classify exhibition works as — (1) Decorative or pictorial (when the intention is merely and purely to produce a beautiful thing). (2) Scientific (accurate mathematical reflections). By using the terms "decorative or pictorial photographs" and "scientific photographs" we should, I think, allay all opposition from artists— not to say painters— and critics (who are right in re- fusing to call photographs works of art), and should be at the same time working in a less pretentious way and in a legitimate pursuit, humble as compared with painting, 'tis true, though'the best results surpass all but the masterpieces of art in beautv. And I would ^ggest that this Society sets the example at their forthcoming Mubition and describes the works submitted into two classes, scien- tific and "decorative or pictorial," for works should be classed ac- cording to their intention. Proposition XV. — That decorative photographs are worth doing (if well done) because they give us certain beautiful qualities art cannot give, hence their raison-d'efre. That the producers of such may prove themselves as keen seers (not artists) of the beautiful as the master artists themselves. They may have art knowledge too; yet, if they be no creators by personal method, I submit they are not "artists." But, then, this does not mean, on the other hand, that mediocre draughtsmen, whose vision is vulgar or obtuse, are to crow over these seeing photographers, for such mediocrities are not "artists" and, indeed, seeing photographers have far more claim to the title, as the masters would allow. Proposition XVI. — That, though photographs are sometimes more beautiful then art, they never equal iS'ature when she sings in tune. Indeed, I submit than when Nature " sings in harmony " she is more beautiful than photography or art, unrivalled in her dehcacy, fineness, and distinction. Proposition X VII. — That " idealism " and " impressionism," if used in connexion with photography, are mere contradictions of terms, and used by slovens in thought — -or worse. Gentlemen, let us conspire not to be called by any false or vain names such as " artists,'' but to produce beautiful decorative work, each of us in his own way. Let us in friendly and unselfish spirit band together for the furtherance of this end, and let the too eager or ambitious (I will not say vain) neophyte remember that the proof of his dehcacy of vision is in a measure what he shows us of his own, and that, as there are few Laura Bridgemans with perfect touch, so there are few seers of the most delicate beauties, because few organisms have delicate vision. Let the neophyte and others re- member that the seers of the beautiful are as rare as the limners of beautiful scenes ; that physiology proves that most are for ever fatally limited to remain without, and no disgrace either, if such have but the honesty and pluck to own it ; the disgrace is pretentiousness and imposture — in pretending to see. Amongst these bUnd have been the vast body of persons who have ridiculed Mr. Whistler ; indeed, nearly the whole press has ridiculed him, and yet, gentlemen, to-day his pictures hang in the most honour- able position in Paris, the city at present the Queen of the Arts, and so it will always be, for I for one tjelieve that truth is great, and will in the end prevail over obtuseness and dishonesty, for I am optimist enough to think the majority of men are fair-minded, honest, and manly, and that, though they maj- for a time let the rogue and the cad live their little days, they wiU in the end arise and put their houses in order and turn the unclean from their temples. As for these propositions, gentlemen, I do not intend to fight over them, for they are propositions, and therefore no fighting matter, but provisional until psychology shall either prove or disprove them. I offer them to you frankly and trust you will deem them worthy your consideration, after which I leave you to accept or reject them,, as your honest judgment dictates. At any rate, they may prove interesting to some of you, at least I hope so, for they are an attempt on my part to solve what has long been a vexed question, a problem to which no satisfactory or rational solution lias hitherto been offered. P. H. Emkhson, B.A., M.B. (Cantab.) PHOTOGEAPHIC INDUSTRIES— THE OPTICAL WOEKS OF W. WEAX, HIGHGATE, LONDON. For many years has the name of Wray been associated with the con- struction of astronomical, microscopic, and similar achromatic object- glasses for high-cla33 instruments of precision. It is only within the past six or eiglit years that the firm has been induced to add to the above departments the sister branch of photographic lenses, which has already developed into one of great magnitude and importance. In the belief that our readers would like to know something, however little, of the inner life of a recognisedly high-class lens-making establishment, we visited the place one afternoon, note-book in hand. The premises are situated on that suburban slope known as North Hill, Highgate. This locality was originally selected as being on an elevation considerably above the lower parts of London, in which smoke and fogs find a congenial resting-place not conducive to the testing of object- glasses for large astronomical telescopes. There is no shop or anything else visible from the adjoining public road which would lead any one to. the belief that just inside of the gate, and within a hundred feet or so of it, were quite a number of workshops, forming the elementary parts of a great factory, the lathes and other mechanical forces in which were in direct communication with a Crossley gas engine, which the Messrs. Wray find more convenient than steam as the motive power. Entering the first of these workshops, we observe four rows of turning April 14, ISnSJ THE BIIITISH JOURNAL OF PHOTOGRAPHY. 283 Istbes extending from end to end. Some of those are elaborately fitted with slide rests, face plates, and simitar belongings incident to such 'machines. At one end we observed an elaborate mechanical appliance which wo could not relegate to the department of either lathe, planing, or Bhaping machine, being unlike anything we had previously seen made ■use of in connexion either vvith the construction of louses, telescopes, or microscopes. This, Mr. Wray informed us— demonstrating its modus operandi — was an entirely new machine they had made for the produc- tion of Iris diaphragms, it being used for cutting and drilling the slots and holes which form a portion of their internal mechanism. This machine, when once set for any special size of tube, did its work with a degree of perfection quite impossible to be attained by the most careful and skilled hand-work. The mechanical resources of the establishment are such as to have enabled them to construct this useful machine on the premises. The blades used range from twenty-four in number down- wards, according to size of tube, and are made of steel about one two- hundredth of an inch in thickness. These are cut out in a screw press, and we saw a large rack full of the steel-cutting tools, one pair of each being used for each size of diaphragm. The blanks for the Waterhouse diaphragms are also cut out in the same way, the apertures being turned in special chucks in the lathe, hard steel gauges being used for the pur- pose. Close by is the riveting machine for fixing the pivots into the blades of the Iris. It is driven by a strap from the shaft overhead, and delivers something like sixty blows a minute, each one, of course, with absolute precision, and is under perfect control, instantly stopping or starting with a slight pressure of the foot. By an ingenious device the pivot is withdrawn from the bed plate after the operation of riveting is completed. So perfect is the working of this machine that Mr. Wray informs us that he has never heard of one of the pivots becoming loose. In the lens-grinding department we saw much to interest us. Com- mencing with the raw material, the glass : this, we learnt, is obtained from Chance, of Birmingham, and Mantois, of Paris, and, in order not to waste any time in grinding any piece containing an imperfection, each was critically examined previous to being placed in the hands of the toughers, who, with coarse emery and iron curve tools, ground it to the semblance of a lens. The way we saw one disc examined will serve as a general description of all of them. This was to form the " flint " element of a rectilinear of four and a half inches diameter, thirty-two inches focus, and to work with an aperture of/-8. It was a disc of considerable thickness, and had been polished not only at repeated intervals on the edge, but also on both sides, all this being done solely for the purpose of enabling the internal structure of the glass to be critically examined. The indices of refraction and dispersion having been ascertained and noted, the body of the glass is then examined through the edges and sides by a magnifying-glass for the discovery of such defects as -tears, strife, or mechanical disturbances of like nature. But an examination extending only so far would not be complete, for there is a powerful factor still to be determined, which is the homogeneity of the glass. Owing to some imperfect carrying out of the annealing process in the glass works, there might be present strata or patches of unequal density. This is tested for by polarised light, which instantly reveals the slightest departure from perfect homogeneity. Not until the glass satisfies all the conditions impUed by the tests mentioned is it sent down to the roughing shop to be ground approximately to such curves as have been determined by the circumstances of each case. Such an examination as we have described is, we are aware, practised by all high-class opticians, and here comes in one point of difference between what we have termed " high-class " lenses and those pretty, low-priced productions redolent of polish and lacquer, which come to this market in such shoals from abroad. Such makers could not possibly afford, even if they possessed the knowledge, to make a selection or examination of the glass, but take it as it comes from the glass works, soften it by heat, and, by discs, press it into the curves re- quired, finally grinding and polishing the surfaces. When done and placed in their mounts, some by a fluke may be passable, whUe others are —well, not so. With our best opticians, both at home and abroad, each lens forma a matter of individual study from beginning to end. But we must follow the fortunes of the particular lens which we left in the hands of the roughers. When it has been brought into shape, it goes into the grinding and polishing shop, where it is ground and smoothed on a tool of the exact radius of curvature necessary, emery of various grades of fineness being used in succession. With each change of emery the workman washes the surface of the glass, and examines it through a magnifier to see that no grits from the penultimate grinding have been left nnground out, and that the surface is that due to the grade of emery last employed. The final grinding leaves the surface in a state of extreme smoothness, although still grey. The lustrous polish is imparted by a tool from which every trace of emery has been removed, and a fresh surface of pitch or some unyielding cement of a nimilar nature has been given. To this, while still warm, a tool the exact counterpart of the other ie applied, by which the true curve is imparted to the cement aurface, to which is now applied the rouge or putty powder requisite in the impart- ing of the highest polish capable of being attained by the glass. This being the way in which the astronomical lenses for which this firm is Celebrated, are polished, its oae has been continued in the construction of their photographic objectives. In the olden times, and even still yet in some cheap factories, the lenses were polished on felt or textile fabrics ; but this causes a rounding of the margins, and is apt to change the figure of the lens. But the lens is not yet finished. It has next to be centered. To this end it is cemented on the (ace of a chuck in a lathe of special construction, and, before the pitch or other cement has set, the lens is moved by little and little from one side to the other until the reflection of a gas flame in front is seen to be stationary and free from wobbHng when rotating the lens in the lathe. When this has been done, and the cement is quite cold, a plate of metal charged with emery is by slow degrees and by screw adjustment brought to bear upon the edge, and continued until the lens is ground circular and is of such a diameter as is required. After cementing' with Canada balsam the component parts of an achromatic lens, blackening the edges to prevent light from being re- flected, and placing the lenses in the cells of the mount, the combination is ready for being tested. Several tests are employed in Wray's establish- ment, one being the examination of an artificial star formed by a thermo- meter bulb filled with mercury. Several of these bulbs are used, the nearest being fixed at a distance of probably 150 feet from the lens to be tested, and it was astonishing to note tjie rapidity with which the trained eye of Mr. Wray could almost in an instant note anything connected with the correction of the objective and give directions for alteration, should such prove necessary. Flatness of field and covering power were ascer- tained by attaching the lens to a camera much larger than the effective covering power of the lens demanded, and to this end trees and the general scenery at a distance, not omitting to mention houses at no great distance, the black windows of which bore small white eaamel letters, lent invaluable slid, especially to any one unversed in the values of the higher optical tests and who desired to see how a lens would perform on an average landscape subject. One of the sons of the founder of the establishment ensconces himself in a quiet comer, surrounded by the other members of the working staff, who devote themselves to the microscopic object - glass department. Another son is at the head of the photographic lens department, while still another member of the family takes cognisance of the astronomical object-glasses, and all that appertains to them, yet is the training of these chiefs of departments so complete that any one can interchange with another. Incidentally, we noticed that the smallest of the photo graphic objectives — those of the wide-angle class — were being made by workmen engaged in the department devoted to microscopic lenses. An inquiry as to the relative demand for lenses with Iris diaphragms ' contrasted with Waterhouse and others, revealed that the Iris is pre- ferred in the ratio of three to one. There is a fully equipped dark room on the premises, and the actual working of any lens can be practically demonstrated in a camera which always stands ready for use. In the brass-turning shop we observed what seemed to us some hundreds of mounts of various dimensions in every stage of progress, there being a preponderance of small ones intended for hand cameras. Standing in the grounds, and at a little distance clear of the work- shops, are two equatorial telescope stands, having all the fittings for the testing of astronomical object-glasses. One of these receives all objec- tives up to five inches in diameter ; in the other, and larger, objectives from six to twelve inches diameter are finally tested on celestial objects, after having passed the preliminary optical tests. Apropos of charges we and others have occasionally brought against artists for the untruthful drawings often indulged in by them, more especially in the case of the sun or moon, we were shown, by Mr. Harry Wray, a couple of photographs that demonstrated the truth of this charge in an effective manner. Placing a lens of fifteen inches focus in a camera, and selecting a time when he knew that the full moon would that evening be within the field of view, be exposed a plate daring the day, and left the camera undisturbed till evening, when the moon was in the scene, when he exposed a second plate, on which he got an instantaneous view of our satellite. On carefully comparing the relative angles sub- tended by the objects in these two negatives (now in our possession), and contrasting these with a picture of a similar scene drawn by an artist, we find that we understated the case when we said that some artists made the moon four or five times larger than it appeared in nature. This business was established in 1850 in Windmill- street, Tottenham- 234 THE BRITISH JOURNAL OF PHOTOGRAPHY. [April 14, 1893 court-road, and was removed from thence to Highgate for reasons already- hinted at. Beginning in a small way, it has grown, until it now gives employment to about two dozen hands— all expert workmen. CENTRAL PHOTOGRAPHIC CLUB. As already announced, a meeting of intending members and those interested in the Central Photographic Club will be held on Monday evening next, April 17, at the Memorial Hall, Farringdou-street, when the chair will be taken at eight o'clock precisely. The principal object of the meeting will be to receive the report of the Executive Committee appointed on March 6 to (1) Select suitable premises. (2) Decide upon what financial basis the Club should be conducted. (3) Draw up a set of rules for the government of the Club. In regard to the first, the Executive Committee immediately ap- pointed a Premises Sub-committee to seek for suitable premises within a limited area which might fairly be considered central, and, after con- siderable trouble and investigation, the Sub-committee recommended the Executive Committee to decide on premises in Fleet-lane, Farringdon- street, as being in every way suitable for the purposes of the Club. The Executive Committee have endorsed the recommendation, and the meet- ing on Monday next will bo asked to adopt it. As to finance, the Executive Committee unanimously agreed that the Club should be administered and carried on by a limited company, so that the liabilities of members might be restricted to the amount of their annual subscription, the profits, if any, after five per cent, has been paid to the shareholders, being devoted to the benefit of the Club. A con- siderable proportion of the capital has already been subscribed by the members of the Committee and friends. After careful consideration, the Committee have adopted the following rules for the government of the Club : — EuLES OF THE Central Phoiogk.iphic Club. I. The title of the Club shall be the Central Photographic Club. I {2. The object of the Club is to provide a central meeting-place for those interested in photography where they may enjoy social and technical advantages. 3. All gentlemen interested in photography shall be eligible for membership. 4. The annual subscription for town members shall be 11. Is., and for country members 10s. 6d. For life membership a payment of 101. 10s. shall be required. The first 500 members will be admitted without entrance fee. Those joining after that number has been reached shall pay an entrance fee of 1?. Is. for town members, and 10s. 6rf. for country. Gentlemen residing within a radius of twenty miles of Charing Cross shall be deemed town members. 5. The management of the Club shall be vested in a Committee of twelve, six to form a quorum, consisting of an equal number of share- holders and ordinary members, to be elected by the members in general meeting annually. The Committee shall have power to fill up vacancies during the current year. 6. An Hon. Treasurer and Hon. Secretaries and an Hon. Librarian shall be elected by the members annually in general meeting, and shall be ex-officio members of the Committee. 7. Candidates for membership must be proposed and seconded by two members of the Club. The name and address of the candidate, and the names of the proposer and seconder must be sent to the Hon. Secretaries at or before the stated meeting previous to the one at which it is proposed to submit such candidates for election. Such names shall be read by one of the Secretaries to the meeting, and posted on board till the next meeting. 8. The election of members shall be by ballot at any stated meeting of the Club, and a vote of four-fifths of the members present and voting shall be necessary to elect a new member. 9. Every candidate on his election shall be notified in writing with a request for payment of his subscription and entrance fee. 10. No member shall be entitled to use the Club until his subscription for the current year has been paid. II. The annual subscription shall be payable in advance on the first day of July in each year. Subscriptions to be paid to the Club Company. 12. Members joining the Club before September 30 shall pay the full subscription. After the end of September and before January 31 the pay- ment shall be two-thirds ; after the end of January and before May 31, one-third ; the subscription of any member elected after May 31 shall be considered payment for the following year. 13. Any person who shall by any means cease to be a member of the Club shall, nevertheless, remain liable for and shall pay to the Club Company all moneys which at the time may be due from him to the Club. 14. Any member making himself obnoxious to the members of the Club shall be reported to the Committee, who shall investigate, and, if necessary, call a special meeting of the Club to discuss the matter ; then, if the majority so decide, the offending member shall be expelled the Club, and lose all interest and benefit in it, such decision to be taken by ballot. 15. An annual general meeting of the members shall be held in the first week in July to receive the report of the Committee, to pass the accounts, to appoint officers for the ensuing twelve months, and to elect members of the Committee to supply the places of those retiring. The newly elected officers and members of the Committee sliall come into office at the conclusion of such meeting. 16. Ordinary meetings of the members shall be held weekly. 17. The Committee may, whenever they think fit, and they shall on a requisition made in writing by ten members, convene an extraordinary general meeting. Any such requisition shall specify the object of the meeting required, and shall be signed by the members making the same, and shall be delivered to the Secretaries. 18. Every member of the Club shall be entitled to one vote only. The Chairman shall have a casting vote in addition to the vote to which he may be entitled as a member. Bye-laws for the' Club House, and such other rules and regulations as may be found necessary when the Club premises are opened, will be drawn up by the Committee, and submitted to the first general meeting of members for approval. It is hoped that as many as possible intending members of the Club will attend the meeting on Monday next. The Hon. Secretary pro tern. (Mr. Thomas Bedding, 2, York-street, Covent Garden, W.C.) has already received a very large number of applications for membership from all parts of the country, and from both professional and amateur photo- graphers, and the Executive Committee anticipate that the adoption of the above and other recommendations to be made will enable them to approach all classes of photographers in London and country with the certainty of obtaining such a numerical support as will result in the formation of the largest photographic club in the world — a club that shall be at once a home, a rendezvous, and resort for all those interested in photography, whether residing in London or the country — a powerful agency in furthering photographic progress, and a representative force in each of the many branches of modern photography. CROTDON CAMERA CLUB EXHIBITION. This Exhibition was held on the Wednesday, Thursday, Friday, and Saturday of last week, when, besides the pictures on the walls, the now customary evening attractions of music, lantern displays, and technioa demonstrations were included in the programme. A display of some sixty or more of the most successful photographs of recent yeai's, by such men as Ralph Robinson (whose loan collection included his fine Sir Frederick Leightoii), Bio-wnrigg {Wiyiter Sunset, &c.), Byrne (direct por- traits and studies of children), Earl Greger, Colonel Gale {An East Country Quay, etc.), H. P. Robinson {Carolling), Seymour Conway, T. J. Bright, and Adam Diston (about twenty-six examples of this master's work, com- prising the ever-delightful Gloaming), Ufted the Exhibition, as a whole, to a point of excellence which the non-competitive exhibits did little to support. The Judges were Messrs. J. Gale and Thomas J. Bright, and the mention of their awards in Classes A and F must suffice, inasmuch as the classes were small and poor. In Class C, for outdoor views (members only), however, some really meritorious work was shown, Mr. C. E. Whitaker's picture of The Gateway, Hever Castle, catching the eye as a technically well-rendered photograph. Mr. William F. Frost's views on The Mole, Mr. G. R. White's series, and A Study of a Mill Pond by Mr. A. E. Isaac, as well as the same gentleman's clever bit of realism in the effects of Winter, being conspicuously prominent. To our thinking, however, the beautifully crisp definition, relief, and panoramic-Uke effects of Mr. Hirst's Deepdene and Arundel constituted the pick of the class. We hope that so manifestly a good and careful worker will be content with effects like these, and turn a deaf ear to the pipings of the foggy school. In Class D {genre or figure subjects, members), a group of Three Fishermen easily and naturally posed was, perhaps, the best ; but the work in the class was not good. In Class F (any subject) Mr. A. J. Sargeant had some capital interior work {Langton's Chapel), and Messrs. W. J. Wright, George Corden, H. E. Holland, and G. R. White were represented by excellent landscapes. In the class for members' exhibits not for competition, Mr. B. G. Wilkinson was a tower of strength with several of his famous studies, and the President (Mr. Maclean) had a good selection, of which we preferred a little picture The Causeway, a waterside study, in which the arrangement of land and water was accomplished with the happiest Aprfl 14, 1893] THE BlUTISH JOURNAL OF PHOTOGRAPHY. 28S artistic efTeots. In the same olase, Hr. O. B. White had a leries of intoriora of dwelling rooms, difficult subjects successfully handled. Useful exhibits of photographic apparatus, Ac, were shown by Messrs. Hurst, & Co., of St. Michacl's-road, West Croydon, and D. P. Roberts, 120, North-end, Croydon. The Exhibition must have given great gratifi- cation to local photographers. It was small, bnt well arranged. The following were the judges' awards : — Class A (Best prints illustrative of hand-camera work) No. 9 (first award), George B. White. Class B (Lantern slides).— No. 22 (first award), H. E. Holland ; No. 25 (commended), George Corden. Class C— No. 18, to 50, Series (first award), William P. Frost; No. 63 (commended), George B. White. No. 67, 69, 70, Series (commended), A. E. Isaac. Class D.— No. 79, FUhennen (first award), C. E. Whitaker; No. 81 (commended), H. E. Nceves. Class E.— No. 105 (first award), Miss J. E. Fooks. Class F.— No. 148 (first award), A. E. Isaac. WEST SUBBEY rHOTOGRAPHIC SOCIETY'S EXHIBITION. TuE fifth annual Exhibition of this Society was held during the week at the Public Library, Lavender Hill, S.W. The competitions were restricted to members, and about one hundred and sixty photographs were placed on the walls. If we remember aright, the Exhibition of last year had the advantage of including a number of Colonel Gale's and Mr. Davison's pic- tares which added materially to its average of excellence. This year no srach assistance is forthcoming ; but, as if by way of compensation, the members' work is undoubtedly superior to that previously shown, although, perhaps, numerically smaller. Naturally an exhibition of members' work is only of confined interest, and therefore, criticism of it in detail is superfluous. Some of the pic- tures, however, well deserve commendation by name — notably an enlarged study of the Waterfall, Battersea Park, by Mr. E. Pointon, possessing great softness and naturalness ; two large platinum views of the choir and nave, Lincoln Cathedral, by Mr. F. P. Smith, capital pieces of interior work ; a delightful view of Eijnsford, by Mr. Winsford, and a triptych by Mr. P. Martin, Seeing the Show, children all agog with expectation in the street, waiting for a Lord Mayor's procession or something of the sort and held back by a man in blue. Mr. E. Calland showed a portrait, which, in the way of "diffusion of definition," would have been bad to beat, sapposing the use of a lens. Two tiny views in carbon, on very large mounts, by Mr. G. H. James, were reminiscent of Mr. Davison, and the same exhibitor's portrait of a lady, a gracefully posed warm-toned pic- ture, was undoubtedly the best picture in the room. We liked Mr. J. S. Bond's well-printed platinotype view of Melrose, and a plough horse piece, A Surrey Team, also by Mr. Bond ; Mr. E. Swingler's river scene with shipping, A Still Day, a refined tender view ; and Mr. W. Graham's minute crisp studies of Caiitor Beach and On the Bure. Mr. J. L. Lyell's capital studies of Indian Architecture agreeably diversified the Exhibition, which contained much other really meritorious work. We may note, in conclusion, tliat the West Surrey Society has its Own journal The Photographic Gazette, edited by Mr. G. H. James. The April number, containing the catalogue of pictures, includes weU-written and practical papers on " Enlarging " by Mr. Agars, " Autotype Printing " by Mr. Calland, " The Dominant Factors of Exposure," by Mr. G. H. Seward, and other instructive photographic matter. The Gazette is a credit to its Editor and the Society. THE INFANTS AND THE PHOTOGBAPHER. Ix the Worthing County Court last week, the Judge delivered judgment in the case of Simmons versus Edwards, which was an action to recover 10s. (id. paid to defendant, a photographer, under circumstances which we referred to a few weeks back. Two sisters, both under age, paid, one the sum of 7s. (id., the other 3«., to defendant to photograph a family group. Defendant expressed himself prepared to fulfil the contract, but the plaintiffs' father forbade the photographing of the family, and, at his instigation, the girls sought to recover the money from Mr. Edwards. His Honour, while pointing out that one action should have been brought, And not two, confessed that he did not pretend to understand the father's reasons for forbidding the photograph. His Honour said that in his opinion the case fell within the Infants Relief Act, 1874, and the contract was void ; and, if not so under the Act, still he thought that the Iilaintiffs, being infants, were entitled to void or rescind the contract. Further, there was the question whether they could get their money back, and whether they had derived any benefit from the contract. Defendant, in his opinion, was in the same position as he was before the contract wan entered into, and he could not treat the making of an appointment as work done. There would therefore be judgment for plaintifTs, bnt without costs. He thought it would have boon much better if defendant had been allowed to carry out the contract. Defendant: "Thank you, sir." ©ur IBlJitorial Eatlt. Elbmentaby Photooeaphy. By John A. Hodoes. In this work, which forms No. 7 of the " Amateur Photographer's Library" (Hazel, Watson, & Vine^), all the various processes of practical photography are described in such simple language as befits a teacher who is imparting his knowledge to young and inexperienced aspirants after the photographic art. In recommending the selection of a camera, he give preference to one of the half-plate size on the score of comfort and convenience. After describing the special features of some of these, and of some of the lenses in common use, the author describes non-actinic lanterns and the fittings of a dark room, the preparation and uses of the various solutions, and, in short, goes through all the m'ocesse.s of making negatives, printing and en- larging from them. The manual will be useful for beginners — the class for which it is intended. [Photogeaphs by H. Yko, Plymouth. A SBBIE8 of photographs of children — or more correctly of a child — attests the skill of this artist. The story is in reality the history of a soap bubble illu.strated by a small series, from the cradle to the grave sort of idea, which tells its own tale. But, quite apart from this, the pictures as a whole and the poses of the chief actor — a pretty little girl — are admirable. The prints are in platinum, and as pictures are charming productions, the e.xpressions on the face being natural and in keeping with the stages of progress of the soap bubble, from its birth at the pipe to its collapse in mid air. RECENT PATENTS. APFLICA-nONS FOR PATENTS. No. 6931. — "An Improved Mask with Border for Photographic Purposes." A. C. JaCKSOS.— Dated Airril 4, 1893. No. 7051. — "An Improvement in or connected with Hand Frames for holding Photographs, Pictures, and the like." W. S. Simpson. — Dated April 5, 1893. No. 7061. — "Improvements in Photogr.aphic Draining Racks, whereby several Sizes lof Plates can be Accommodated together or separately." W. Tylab.— jOa^eii April 6, 1893. No. 7231. — "Cheney's Retouching Apparatus or Retouching Machine for Retouching and Stippling Photographic Negatives and other Pictures." J. Cheney.— flaferf April 8, 1893. No. 7281. — " Improvements Relating to the Production of Negatives." E. Albert.— Z)afed April 8, 1893. PATENTS COMPLETED. Improvements in Photographic Hand Cameb.is. No. 8324. John Skynnbh Baily Bell, 3, Wentworth-place, Newcastle-upon-Tyne. — March 4, 1893. My invention relates to and is for improvements in apparatus for photographic hand cameras, aud I carry it out in the following manner : — The camera case may be of the usual shape or form, or otherwise, and with any additional or necessary adjuncts if required. Within the camera, and immediately behind the lens, I have the exposure chamber, and behind this chamfSer, and divided from it by a suitable par- tition, there are two chambers, one above the other, and divided by a hori- zontal plate or partition at or near the middle of the height of the camera. The upper one of these chambers is the unexposed chamber for the reception of sensitised plates, aud the lower oue is the exposed chamber, to receive the sensitiset) Brussels Intkrnational Congres.sks, 1889-1891. Mr. Leon Warnehkb read a lengtliy paper on this subject, describing the origin and labours of the two Congresses, and concluding with a detailed account of the decisions arrived at with regard to photographic standards and units. He mentioned that the next Congress would be held at Geneva in the ensuing summer. [We shall make extracts from the paper when it is published.] Mr. Warnerke said that Captain Abney wanted him to make a critical report, but all he would then say was that the work was conscientiously done. At the same time the decisions of the Congress were such that they could not be adopted in this country, particularly with regard to the size of plates, screw threads, and Hanges. Mr. Chapman Jones said that photographers had not troubled much about these congresses, but they had not had till now any conuected account of them. With regard to a standard light, it seemed to him that they would, after all, have to go back to standard candles : but he would like to a.sk Mr. Warnerke whether the congresses had got us any nearer a standard light of any other kind. In the course of his reply, Mr. Warnerke admitted that this question as well as that of the determining of the sensitiveness of plates, was yet unsolved. Mr. G. ScAMELL said that, as regards delegates to future conferences, the affiliated societies should be invited to act in the matter. The Chairman, in closing the discussion and moving a vote of thanks to Mr. Warnerke, said that Mr. Warnerke had gone to very great labour in drawing up the p.iper, but it was unfortunate that photograpliers would not trouble about the work of the congresse.s. One of his (the Chairman's) objec- tions to the decimal system was the difficulty there would be in abolishing it in favour of the duodecimal, whicli he thought would ultimately be adopted. The inch and the foot were more convenient than the metrical measure, as they were so easily appreciated by people in this country. LONDON AND PROVINCIAL PHOTOGRAPHIC ASSOCIATION. April 6, — Mr. E. J. Wall in the chair. Determination ok Plate Speeds. After the disposal of other business, Mr. G. F. Williams read a paper on this subject [see page 229]. Mr. .\. Cowan said he would like to have the chance of meeting some of the points in Mr. Williams' paper. In his (Mr. Cowan's) opinion Messrs. Hurter & Driflield were not such fools as platemakers seemed to think. It was impossible to judge of exposure by eyesight. Messrs. Hurter & Driffield's test enabled one to obtain the exact rapidity of any plate of unknown rapidity. The exposures could just as well be made to daylight as to candle-light, .and he (Mr. Cowan) would undert.ake to prove that to whichever light an exposure was made the results would be identical. Mr. W. E. Debenham agreed with Mr. Cowan as to the general similarity of the iiehaviour of plates to caudle-light as well as to daylight, with the exception of orthochromatic plates. The difi'ereuce in results given by Wai'nerke'a sensi- tometer to daylight and caudle-light was much exaggerated. Mr. J. Stebry said there were four factors in the Hurter & Driffield system which were estimated sejiarately. These were, relative exposure, relative degree of developer, the character of the plate itself, and the chemical fog, which varied in dillerent plates, and which, if we estimated it simply by the eye, made it necessary that we should eliminate the action of the other three factors. But chemical fog did not affect the matter at all. His chief point, however, was as to the relative amouut of developer to use, and in that con- nexion he would like to ask Mr. Williams how to distinguish between the effects of twenty-five per cent, extra exposure and twenty-five per cent, extra de- veloper, as both increased density, but in a different manner ? It was distinguishable by the photometer numbers, the speed showing by the relative position of the curves, and the developer by the angle which the straight lines made with the base lines. Fog was estim.ited by direct measurement. It was impossible to make two plates which were identical, and thus judging results by the eye was an extremely fallacious plan. To estimate density by this plan it was easy to go utterly wrong, as the surroundings upset the estimation. Mr. James Cadett observed that Air. Williams had asked the supporters of the Hurter & Driffield system to go before a jury of practical photographers to judge a question which they knew nothing about. He could hardly ex- pect that system to be accepted by the people who had no practical experi- ence of it. Mr. Williams had called the system a fiasco, and plates tested by it utterly worthless, and in that he had shown bias. We had been in the habit of reading the speeds of plates by what we observed in the shadows. The action of light was to produce density on development, and density must therefore hold some relation to speed. It was the oliject of Messrs. Hurter & Driffield's system to show that relation. He (Mr. Cadett) had given plates which yielded different densities to different photographers to test with various exposures, and errors of about 300 per cent, were obtained by the camera. It was in confusing density with speed that Mr. Williams condemned the system, basing his condemnation on what some platemakers had put on some boxes of April 14, 1803] THE iJRITISH JOURNAL OF 1>HOTOORAPHY. atr plates. He, however, shouUl Imvejtcstwl his system ag&inst the photometer. He admitted that his own plates Imd Iwcn in one instftnce marked too high ; their ipeed, instead of 130, should have been 108. As regards orthochromatic plates, an enonnous dilTeruniie in their orthochromatic effects to candle-light and daylight had been noticed, but with his own plates, which were not ortho- chromatic, Mr. Driflield had found that they obeyed the same constant. Mr. Driffield had also found plates tested by caudle to give exceedingly good negatives in daylight — he had, in fact, not observed any difference in their qniditie-s in that respect. Mr. Cowan observed that he had tested plates by the candle, and was able to tell thi- maker of the plates what amount of exposure he could give. Mr. Cadett (continuing) put in a ple.i for the use of the photometer, saying that they were unable to judge of density by the eye, wliereas the photometer showed it instantly. Taking the case of two plates which had received identical exposures, the only difference might be that one would have a higher density than the other. One would look umler-exposed, and the photometer woidd indicate a lower cnne. The same detail would come out with a slower plate, but measurement of the density with the photometer would at once show the difference. In one case a difference of 300 jier cent, had been found. If density was not related to speeil, how was it to be made use of? He (Mr. Cadett) thought Me.'isrs. Hurter & Driffield's principles should be attacked. Alluding to Mr. Cowan's exi>eriraents, he said that, under the conditions, he was a far better juer reflectors, hence limelight is not satisfactory. Magnesium ribbon for high lights and gas for shades recommended." Mr. Dean then reaewport-street, Bolton. Doublet lens, bv A. Boss, 18x16, has been used regularly for plates 21x18; exchange for 15 X 12 wide-angle tourist camera, half -plate.— Address, A. Ooi & Co., Tavistock- chambers, Nottingham. Will exchange Emmerson's head rest for two backgrounds, on« in-door and one ont ; or half-plate camera and lens, for out-door work ; must be perfect.- Address, F. MoOBE, 36, WoUaton-road, Beestou, Notts. Will exchange a heavy burnisher, by Richardson, eighteen-inch bar Cosoillating) , perfect condition, and with gas burner ; wanted whole-plate wide-angle lens, any make.— Address, 0. Bennett, lOt, High-street, Ljmington, Hants. €ottesJt>ontrence» Correspondents sJtould never vyrite on hoth sides oj the ■paper. No noiice i» taken of communications unless the names and addresses of the writers are given. MR. PEINGLE AND THE SANDELL PLATES. To the Editor. Sib,— Although Mr. Pringle has confined his reply to my letter of the 17th ult. to another journal, I think the matter of such universal interest that it should get directly into the hands of your readers, and so you will oblige by inserting the following contribution to it. I hasten to reciprocate Mr. Pringle's kindly feelings. Mr. Pringle has been a friend to ourselves, speaking for my Company, and to myself, and trust he may ever remain so ; but there happens sometimes in human experiences a period when it is well to be saved from one's friends, and this I have taken to be one of those interesting occasions. Mr. Pringle expresses regret that I did not attend at the meeting of the Camera Club. Well, I thought the matter was so simple that, in the hands of such an expert, the subject was quite safe ; secondly, I disliked the appearance of " exploiting " at scientific meetings ; and, lastly, I did not think it con- sistent with my amour propre, inasmuch as I had some time previously been advised by Mr. Pringle that I should not be considered worthy of the Club membership. Of the first idea I have been altogether disabused, and it is entirely due to Mr. Pringle's handling of the subject that it has been thought desirable to give instruction in the uses and capabilities of the plates by demonstration at the Societies. Mr. Pringle seems to wish to represent my former letter as dealing " mainly with opinions." Nothing is further from my desire. I want facts, and facts only ; and I maintain the facts of the case are so easy of proof as to be within the reach of all. Mr. Pringle objects to my use of the adjective " preposterous." I can only repeat that the idea of stripping the films in practical negative mt^ing is preposterous, and consider I was justified in being so emphatic on the point when a gentleman, Mr. Gregor Grant, who admittedly had received instructions from Mr. Pringle on the proper use of the plates previous to starting on a trip, is reported to have said at a meeting of the West Kent Society that he gave enormous exposure, developed, and stripped off the top film ; but I understand even then nine good negatives were secured out of twelve, the remaining three being under-exposed. I take it the latter were the cause of Mr. Grant's adopting Mr. Pringle's notion, that a little over-exposure produced a failure with the plates. In discussing the question of rapidity, I contend I am entitled to have from Mr. Pringle some suggestions as to why he should go out of his way to represent the plates as slow, in order to release him from any suspicion of being disingenuous. Either he must imagine I cannot make a fast emulsion, or must have an idea that the successive coatings interfere with one another. Mr. Pringle must surely know there is every inducement to put the most rapid emulsion on the surface, for, with the increase of rapidity, halation is increasingly troublesome in the single film. As a matter of fact, the plates are as rapid as any plate of any make I have ever tested, and I am more than sanguine of soon being able to provide a plate of much greater rapidity still. Mr. Pringle's assertion at the Camera Club, " I found that in a view with trees in it, the normal exposure to get a good negative on the top film was ten seconds at/-32," if unaccompanied by an extempore explana- tion, was an outrage. I will here point out that the questionable advantage possessed by the ordinary plate of the supplementary exposure from reflection (which I maintain is stupidly called halation) is absent. Why I think the term halation stupid is, because it detracts attention from the undue density, and what may be called the inner effect of the reflected rays when not sufficiently strong, or the angle of reflection is not large enough to produce the halo. Mr. Pringle, in his use of the adjective " absurd " in connexion with my assertion as to the practically unlimited latitude of the plates is, I submit, somewhat unscientific. If it is possible to do, as I have done, give an exposure on an open landscape of half a second, and another of one hour with the same stop (and, in all probability, six hours would have answered equally), is my claim unjustified ? I should be glad to know who requires greater latitude. Mr. Pringle says he has not found the plates an absolute cure for halation. I shall esteem it a great favour if he will furnish me with details of the alleged failure, and will guarantee, if the exposure is within the province of what can be fairly described as practical photography, to make a negative free from it. On the question of quantity of light passing a film, Mr. Pringle appears to give himself entirely away, or I cannot understand his language. He says, " I tliink under-exposure is one of the most certain ways to produce halation." Now, taking it for granted that the halation meant is reflec- tion, and as the reflected rays are only a small percentage of those trans- mitted, it stands to reason that a large quantity of lipht has passed the fllm even in the cases of under-exposure. Then, am I right or wrong in claiming a great advantage for the double films in cases where one wishes to develop up all that is possible ? Now on the question of amenability to development. I have not the advantage of a knowledge of the results obtained by the savants referred to as having " studied the subject." It has been a matter of daily, almost hourly, study to me for the past fourteen years, and this is the only way in wliich I can account for the fact that a weaker developer is necessary for a slow plate than for a rapid one, and also for another fact, that a weak and restrained developer with a rapid plate will furnish a finer-grained negative than a strong one. Why this, unless it is that the finer grains are more easily reduced? This, in my opinion, also furnishes the correct answer to the Kev. F. C. Lambert's question as to the appearance or non-appearance of the posi- tive effect in negatives, propounded at the Camera Club on the same evening. Mr. Pringle, I expect, will agree with me that light and heat are only different manifestations of the same iiatural phenomenon. Now, in sensitising an emulsion, heat is as necessary as light is in making a nega- tive. We know the effect of light is, up to a certain point, to facilitate or render possible the development to maximum density ; beyond that point it renders it more and more difficult, and at last it makes development by any known method an utter impossibihty ; in other words, the salt of silver is what is termed perfectly solarised. Then I suggest the action of light and heat being similar, that in the more highly sensitised emulsion we have an approach to the effects of solarisation, and consequently density is less easy of achievement, as it is well known to be with the most rapid emulsions. I can assure Mr. Pringle there are many items to be found in the philosophy of a dry-plate maker, which are not to bo found in the philo- sophies of the majority of our handbooks ; neither is it fair to expect it. We, as emulsion-makers, make thousands of gallons of emulsion of different kinds during the year, whereas our authors may make their few half pints. . . In conclusion, I can only beg of Mr. Pringle not to fail to pay a visit to the Exhibition which is being lield during next week at 24, P.egent-street. If he cannot there find that I have more than proved my case to the hilt, I shall be surprised.— I am, yours, &c., J. T. Sandell. Thornton Heath, April 10. REDUCING ACTION OF HYPO ON AMIDOL-DEVELOPED NEGATIVES. To the Editor. Sib, — The reducing action of hypo on amidol -developed images is not confined to bromide paper. A few days ago I developed in amidol and fixed in a somewhat strong bath two hand-camera exposures. The negatives produced were fairly strong and of good gradation, without fog, and fixation appeared to be complete. I rinsed them under the tap'for about three or four minutes, and placed them in a draining rack, intend- April 14, 1808] THE BRITISH JOURNAL OF PHOTOURA±HY. ing to finish washing them as soon as I had developed the remainder of the exposed plates in the magazine. I was then called away for two or three hours, and, aa soon as I returned, at once proceeded to complete the washing of the negative. To my consternation, I found only the merest ghost of an image left. There was no sign of fog, and the gradations had not sufTored. It has long been an article of my photographic faith that negatives underwent merely apparent reduction m the fixing bath, and that pro- longed fixation did not perceptibly increase this apparent reduction. An exception must evidently be made in the case of images produced by amidol. I would recommend a comparatively weak fixing bath for both plates and paper when this developer is used.— I am, yours, Ac, 54, Lo/tiu-iO(ul, W., April 7, 1893. L. Crossl*. To the Editor. Sib,— In the last two issues of The British Journal of Photoorapht I have read letters on the above subject, and write these few lines to inform your readers that, having used the above developer upon several different brands of dry plates for negative work, I have noticed that when the negatives have been left in the fixing bath for, say, two hours, their density appeared to be reduced a little as compared with their density after about half an hour's stay in the fixing bath, which for all ordinary plates is the length of time I consider necessary in order to thoroughly fix the image. I may also mention that I have even left negatives developed vnth amidol for at least twelve hours in the fixing bath, and, although they have been a little more reduced in density, none of the finest details appeared to have suffered in the least, and in no cant did the i/iiai/c entirely disappear. It will be interesting to many of your readers to know that negatives developed with pyro, hydroquinone, eikonogen, and rodinal will be reduced a little in density if left in the fixing bath for several hours ; hut I do not think that amidol-developed negatives are reduced to a greater extent than those developed with the other developers above mentioned — at least, this hae been my experience. An ordinary, and not an acid, fixing bath is always used in my dark room ; therefore I cannot say what effect the latter or any other kind of fixing bath may have upon the image. The foregoing facts riiay set many of your readers' minds at rest as regards the permanency of their negatives — from this cause, at least ; indeed, this is the only reason why I wrote this letter. — I am, yours, &c., J. T. Hackktt. Fleet, Hants, April 7, 1893. CYANIDE OF POTASSIUM. To the Editor. Sir, — May I be allowed to correct a statement you make in answer to correspondents, re cyanide of potassium ? You say this is only sold by " qualified pharmaceutical chemists." All registered chemists can sell it ; but the latter are not pharmaceutical chemists, although both are registered as duly qualified to sell poisons. At the same time, you will find it in the British Pharmacopoeia method of making its characters and tests. — I am, yours, &c., J. W. Wright. 141, St. James'gstreet, Burnley, Lanes, April 7, 1893. ALBUMENISED PAPEE VERSUS P.O.P. To the Editor. Sir, — As so much has been written upon the superior permanence of P.O.P. paper over albumenised, there is one test I have never seen mentioned, viz., hot water. Our old friend will stand boiling ; the other — well, try it. I should recommend amateurs to be wary of discarding old and tried friends.— I am, yours, &c.. Amateur. April 8, 1893. [Our readers will he amused to be told that the " permanence " of gelatino-chloride print.s is open to question because they will not resist the application of boiling water ! Our correspondent's test is »uch a ridiculous one that it obviously explains why he has never seen it mentioned. — Ed.] » TRADE DEPRESSION— THE CAUSE AND THE REMEDY. To the Editoe. Sib, — Your valuable Journal, ever alert to the interests of those who seek a livelihood by, and are entitled to a position in, our much-abused profession, will gladly entertain the above — the burning photographic qnestion of the day. The thorough practical remarks of " N'Importe " in your issue of March 24 are a step in the right direction. So let us pro- ceed to consider the facts. When circumstances are adverse to pro- gress, we must understand the cause thereof, and what is conducive to improvement ; in our case, this is not difficult. While we submit to incompetents usurping the rights of genuine aspirants, the present state of matters will prevail, to the discredit of a nation whose boast is, " Liberty and the suppression of all unrighteousness," Let us follow the expedient adopted by other trades and professions, and prove our genuine- ness by technical examination and registration. Those unable to survive a test would find their proper insignificance seeking pastures new, while those who proved their superior claims for a position in the photographic world would no longer incur the sceptical view, as one of the many sheep in the fold (black included), but as a distinctive class. To further our interests we have established our National Association of Professional Photographers, Photographic Society of Great Britain, and others. If they wish to uphold their profession as an honourable one, will they not endeavour to suppress the existing evil ? In this advanced age, when competition is so keen, we must establish measures for the protection of a genuine business career. Then, and not till then, can photography maintain the high position which it is destined to, and deserves to occupy, as one of our many arts and sciences. — I am, yours, &c., April 10, 1893. Onus Pbobasoi. PROPOSED HAND CAMERA CLUB. To the Editor. " The cry ia still they come.'' Sir, — I note in your last impression a proposal for a Hand Camera Club. As there is now a Photographic Society in most parishes, I should have thought that the hole cut in the stable door for the fowls would have been large enough for the chickens ; however, I may be wrong, and the new Club may fill a long-felt want, after all. Should the proposal succeed, I would suggest a " Half-plate Club," a " Seven and a Half Five Association," and a " Whole Plate " Society (with power to add to their number), the subscription to be in proportion to the size of the plate adopted, thusly, quarter-plate, 2s. &d. ; half-plate, 5s. ; 7J X 5, 7s. 6d. ; whole plate, 10s. ; and, when these are all in good working order, an " Iris Diaphragm " Society, a " Portable Symmetrical " Club, a "Tele-photographic" Association, and a "Concentric" Union might be started. I was going to add an Eccentric Club, but possibly, by the time the others are in full swing, there will be several of these under other titles. I would also suggest that, if these Societies are formed, some of the meetings should be arranged for the daytime, as at present there are only six evenings in the week available for those who make either a hobby of, or a livinc by, photography. — I am, yours, Ac, Drop Shuitke. April 10, 1893. THE GENESIS OF THE GAS REGULATOR. To the Editor. Sir, — AUow me to say that Birrell's Gas Regulator was patented and used on his automatic oxy-hydrogen apparatus on July 25, 1875, seven years earlier than 1882. His regulator is different from all the other regulators, his is a Bellows and Stud Acting by means of a lever and Con- necting Rod on a Keyed Cork. The latter is a more certain form than a valve as any dust between it and its seat regulator renders the regulator entirely useless. His has one of his Anti-friction Keyed Cork which reduces the friction of the key to a minimum.^I am, yours, &c., William Birrell, 109, Graham-street, Airdrie, N.B., April 10, 1893. anetoew to ©orresponDcnts. ,* All matters intended for the text portion of this JoubnaL, including mieries and Exchanges, must be addressed to '' The Editor, The British JOURNAL OF Photography," 2, York-street, Covent Garden, London. t»- attention to this ensures delay. ,* Correspondents are informed that we cantwt undertaJce to answer corn- municattons through the post. „* Communications relating to Advertisements and general business affairs should be addressed to Messrs. Henry Greenwood & Co., 2, York-street Covent Garden, London. Photoqbafbs Reqistered ; John AndergoD, Dairy, Ayrshire. — VhMograph of the JSot}iit Lodge ofScoiXani, Mackintosh & Co., Kelso. — Four photograp/is of the Qrave of the late Q. A, Bairdm R. Davis. — The prints will not curl if they are well rolled. Hermann Schnacss. — We shall be pleased to receive the article. 240 THE BRITISH JOURNAL OF PHOTOGRAPHY. [April 14, 1893 Bbutus. Your post-card was quite inexplicable, please write more fully. John A, Llotd.— Sharland, Thavies Inn, Holboru-cirous, is the address you lost. .B_ 0. We have no information as to any imminent scientific Exhibition at Islington. XXX.— Try the effect of refixing the plate in an acid (bisulphite of soda) hypo fixing bath. H. W. H.— The tincture meant Is the compound one in which water is the solvent. Collotype. — Apply to Messrs. Waterlow, Messrs. Bemrose, or the London Stereoscopic Company. ■A. E. Platt. — The negatives are out of our possession. Try either daylight or magnesium, whichever is most convenient at the time. J. W. — Practical information on the subject of process-block and collotype work is given in the Editorial article of the last Alma:? AC. John Buchanan.— 1 : 15 and 1 : 6 in the formula mean solutions containing respectively one part of gold chloride to fifteen parts of water, and one part of hypo to six parts of water. E. H. — Hydroquinone, as well as eikonogen, may be obtained from all the dealers. Neither article is, or ever was, kept by ordinary druggists. You are misinformed as to its being withdrawn from the market. T. G. Shape.— If the seller says the rose tint on the albumen paper is per- manent, it ought to be. The thing is easily tested. Expose a piece in a pressure frame to the sun for a few days, part of the paper being shielded by a mask. ■COMP.vRE. — 1. No bag is needed for changing the plates, the reservoir being complete in itselt It is adaptable to any camera. 2. The lens mentioned will, when stopped down to /-8, do all the work that can be done by a lens in which this is the maximum aperture. A. E. — The combined toning and fixing bath, at one time universal, was abandoned for albumen paper prints some thirty years ago. The theory of its action will be found iu some of the earlier editions of Hardwich's P)ioto- graphic Chemistry ; see the sixth and seventh. :Septimus. — Any of the wholesale stationers who supply enamelled paper for lithography will also supply paper suitable for collotype. Sometimes the plates have to be modified to suit any particular make of paper. But the makers can modify the surface of the paper to order. Of course, they will only do this when a suflicient quantity is ordered at a time. W. HoBBS. — We cannot hazard an opinion as to the safety of the mounts. Methods for ascertaining the influence of the mount upon the photograph have been published in the Journal. In the meantime you may plaster, by means of water, a print face down upon a mount, and plaice under pressure for a fortnight. You will then see whether any signs of spots or other im- perfections are apparent. 'T. RowE says : "I always see it recommended for the photo-lithographic and other mechanical processes that wet collodion be used for the negative. Will not dry collodion do as well '. Siu'ely a negative may l)e as good by one process as it is by another ? " — It matters not by what process a negative is made, so long as it is of the kind suited to the work. Wet collodion yields negatives of the ch.aracter best suited to most of the photo-mechanical processes. It is for that reason that it is almost universally employed. A. Mounter. — If eight girls are employed in the establishmentyou are engaged in, we should certainly say that it comes within the Factory Act, and that the emjiloyer is not justified in keeping the hands employed for so many hours a day, particul.irly with only three-quarters of an hour for the three meals. You are certainly entitled to the Saturday half-holiday according to the Act. . Communicate with the factory inspector of the district, or write direct to the Home Office, Factories Department, Whitehall. According to your account, you are all being "sweated." C. Fermer.— We are not familiar with the "liquid gum" named, and do not know its composition. Many of the cements sold ready for use, though ex- ■cellent adhesives, are quite unsuited for photographic "mounting purposes, by reason of the injurious action they would have on the print. Some of ■these liquid cements, we are told, contain bichloride of mercury as an anti- septic. We need not say the effect such a one would have on a silver picture. As a mountant, nothing is better thau starch, or gelatine, and either is easy of preparation as required. *1. W.— When a youth is apprenticed, the indentures, whether a premium is paid or not, shoidd be properly drawn out and duly stamped, otherwise they are not binding on either party. It should also be clearly stipulated as to what the youth is to be taught ; otherivise the apprentice, at the end of his term, may find that he has wasted his time to no purpose, unless he obtains redress by legal proceedings. In the indentures have it stipulated the time he is to serve in each department, so that the whole of his time is not ex- pended in mere drudgery. See letter and comment in our penultimate issue. D. McMahon.— 1. If the collodion you have made peels ort' the glass while the plate is in the silver bath, it shows that it is not suitable for negatives. In a first essay of the wet-collodion process, a beginner had better purchase his collodion of one or other of the well-known makers, he will then be sure of obtaining what is neces.sary. 2. The "metallic markings " on the glass are due to its not being perfectly clean. 3. In working the collodion process, the plate is not placed in a dish for development. Why not get a lesson or two from an old hand, as you wish to work the process for commercial purposes ? you would save much time by so doing. J. R. Willis writes as follows : " I often see it mentioned, in connexion with the stability of some of the old silver prints, that they were made on slightly albumenised but heavily salted paper — fifteen or more grains to the ounce — and sensitised on a hundred, or stronger, grain bath. Can you tell me who supplies such a paper, ready sensitised, as I should like to give it a trial, for all my prints show signs of deterioration after a year or two ? " — Such paper, either sensitised or unsensitised, is not a commercial article now. If our correspondent requires such a paper, he will have to prepare it himself. Photoobaphic Club.- April 19, Cold Bath Platinotype Experiences. 15, Saturday Outing, Hadley Wood; meet at Hadley Wood Station at three o'clock. Messes. Marion & Co. write : " It may be interesting to you to know that the successful group taken at Windsor by Mr. Cartland was with Slingsby's flashlight apparatus." Brlxton and Clapham Camera Club. — At the next meeting on April 18, Mr. T. C. Hepworth, F.C.S., will lecture on Photography applied to Journalism, with lantern illustratioos. London and Provincial Photographic Association. — April 20, Adjourned Discussion, Determination of the Speed of Plates. 27, The Influence of tlie Hand Camera, W. D. Welford. May 4, Developers, Technical Lecture of the Series, E. J. Wall. The London Sensitised Paper Company writes : " To meet the demand for our albumenised and matt-surface sensitised paper, ' Sans egal ' brand, also to provide accommodation for machinery and plant for two new brands we are going to introduce at an early date, we have found it necessary to acquire new and spacious premises — Cavershara Works — which we are fitting up for the production of silver printing papers. Our new ofllce address is 2a, Caversham-road, N.W." The Bradford Amateur Photographic Society hold their annual Exhibition at the British Art Gallery, on May 1, 1893. The form of entry to be returned on or before April 28, to the Secretary, 15, Beech-grove, Pollard-lane, to- gether with a postal order for entrance fees, payable to Mr. F. B. Pickles. The entrance fee is 2& 6<2. for each class. Received.— An Amateur ; T. H. Faulks ; Morgan Backus, many thanks. We shall probably utilise. ilR. W. M. Warneuke, of Glasgow, occupies a considerable space at the Chicago Exhibition with several large direct portraits, some of them about 40 X 30 inches, in sepia platinotype. Mr. S. Herbert Fry writes : "I shall be much obliged if you will permit me a little of your space to add the following remarks to your report of the meeting of the London and Provincial Photographic Association for M.arch 30. The Chairman of the meeting, Mr. J. S. Teape, showed some comparative results upon a ' Saudell ' plate and one of another maker. If the result appeared somewhat to the disadvantage of the multiple-coated plate, it was only because it was not given the trejitment which would develop its qualities. A multiple-coated plate can be spoiled in use. In this case it was. Given an exposure which is longer than what I may describe as a normal exposure, development must always be tentative. By this I mean development must be commenced with a solution which is both weak and restrained. If this be done, and the developer strengthened only sufficiently to produce an image of the same character as the image upon an ordinary dry plate, then the inherent advantages of the multiple-coated film will be utilised to their utmost. Backing, judiciously done, does in a large measure prevent halation, but the advantages of multiple-coated films are not confined to this one point. They are also practically over-exposure-proof, a quality which is by no means be- stowed by backing." *»* Owinff to great pressure oh our columns this week, we are compelled to hold over several interesting articles and other communications that we have i» type. OONTENTS, lens standards , S2S the city and guilds institute AND photo-mechanical WORK .. 225 crystal palace photographic exhibition 227 AMERICAN NOTES AND NEWS 229 determination of plate SPEEDS. By G. F. WILLIAMS 229 NATURALISTIC PHOTOGRAPHY. By P. H. EMEKSON, BA., M.B. (CiOTAB.).. 231 HOTOORAPHIO INDUSTRIES: THE OPTICAL WORKS OF W. WRAY, HIGHQAIE, LONDON 232 PaoB CENTRAL PHOTOGRAPHIC CLUB 234 CROYDON CA.MERA CLUU EXHIBITION SM WEST St;RREY PHOTOGRAPHIC SO- CIETY'S EXHIBITION 235 THE INFANTS AND THE PHOTO- GRAPHER 21:. OUR EDITORIAL TABLE •£'■■ RECENT PATENTS as'. MEETINGS OF SOCIETIES 2Si; FORTHCOMING EXHIBITIONS 5." EXCHANGE COLUMN iSf' CORRESPONDENCE 23i ANSWERS TO C0BBESP0MDENI8 2:4 THE BRITISH JOURNAL OF PHOTOGRAPHY. No. 1720. Vol. XL.— APRIL 21, 1893. THE CAMERA CLUB CONFERENCE— VAN DER AVEYDES PHOTO-CORRECTOR. It is difficult at first sight to account for the lamentable falling off that this year cliaracterises the gathering of the members of the Camera Club at the annual conference which was held on the Wednesday and Thursday of last week. The attendance altogether was meagre in the extreme, and, but for the presence of the press and a few others belonging to the outside world — at the second day's proceedings six of the press in an attendance of eighteen — it would have been simply appalling. We have said that at firet sight it is difficult to account for this, but imagine that a factor towards the solution of the problem is to be found in the attitude lately taken by the Club in its relation to the public by interdicting the outside press from publishing any of the papers which from time to time are read, or the communications made at the meetings. It is only in accord with human nature that those who have anything valuable to say would prefer to have their dicta pre- sented to the whole world rather than be confined to the limited number of the Club members who may liappen to be present on the occasion of such communication being made, and thus be inclined to select some other wider channels for the dissemination of their ideas. In adopting this new exclusive course, the executive are acting quite within their rights, but they might consider whether it would not be a kind and graceful act to open their doors, so far as publication is concerned, to their professional and less favoured brethren throughout the world. It seems we were not wholly right in our surmise lastweek when indicating, as we did very briefly, the direction wliicli ^Ir. William Taylor (not Thomas, as we had it) would take in his paper on the Eitahluhing of Standarth in photography, for this paper was of wider scope than we had anticipated, and not merely em- braced the screws and fittings of photographic lenses, but every point on which there was likely to be a divergency of opinion, such as the metre or the yard ; the centimetre or the inch ; the granmie or the grain ; the sizes of plates and films, itc. His paper, however, was not so much practical as philo- sophical. The knowledge that Mr. Henry Van der Weyde was to disclose the secret of his so-called photo-corrector on Thursday evening lirought a larger attendance than had hitlierto been tiie case. Pending the time when in another week an exliaustive paper is to be read on the subject before the Society of Arts, and which we will publish in due coiu-se, we may here give the following brief explanation of what an artist might call the photo-corrector, but which would be designated by a scientist as a photo-dis torter, each of them being right from his own particular point of view. Let us suppose that the hands, or the feet, the nose, or, in short, any part of a sitter were, from the nearness of the camera, represented in the photograph on a scale somewhat larger than was quite satisfactory to the fair sitter, the ([uestion arises how are these individual portions to be reproduced photographically on a less accentuated scale, and so as to be in harmony with the desires of the sitters, if not of their actual measurements "! In addition to the ordinary or primary lens in front of the camera, and by which the image is formed, there must be interposed in the path of the rays coming from the lens to the ground glass one or more otljer lenses having a peculiar form, and mounted so as to be adjustable directly in front of the offending hand, nose, or foot, or, for that matter, of the whole head, for Mr. Van der Weyde is of opinion that many heads are, speaking artistically, formed on a scale too large for the body, and should therefore be curtailed in dimensions in order to fulfil or satisfy the conditions of art. By the interposition of the lens referred to, the focus of such rays is virtually short- ened, and the size of so much of the picture as is produced thereljjT is reduced. The form of the lens required to effect this is peculiar ; it is not plano-convex, but as if a plano-convex lens were cemented to a disc of fiat glass, and made to rise almost imperceptibly from the surrounding piano instead of suddenly — very much, in short, as a gently undulating hill would rise from a level prairie or plain. This would undoubtedly reduce the dimen- sions of the portion acted on, but it must do so at the cost of magnifying all the surrounding parts. This will be apparent if, instead of a lady's hand or her nose, or any other part of her figure, the central spots on a chess-board be selected for this class of remodelling or reducing in dimensions, leaving the margins unaltered. Just try to imagine how this could be done. The law of compensation demands that the space vacafed by the diminution of one part must be added to its immediate surroundings ; that the reduction, say, of the mouth, must be attended by the enlarging of the muscles or space in its vicinity. Mr. Van der Weyde admits that photography cannot lie, ojitirall;/ ; but lie says optical truth is not visual truth. As far as jjhotography is concerned, optical truth is the result of a mere mechanical impression on a plate, which, while some- times wonderful and beautiful, is sometimes so brutal in its fidelity, and microscopically vulgar, as to give a disagreeable surprise. Visual truth, on the other hand, depends for its appreciation on the artistic sense and power of observation on the individual, which he claims to be hereditaiy. Whereas in 242 THE BRITISH JOURNAL OF PHOTOGRAPH i. [April 21, 1893 the fornaer the camera fociisses every spot at the same moment ■without favour or prejudice, in the latter they have to please the family relatives and friends of the subjects wlio are most familiar with their appearance, and in this case the visual truth is the outcome of loving and friendly contemplation. Mr. Van der Weyde is undoubtedly a clever artist, and pro- duces admirable work ; but wc shall prefer waiting before writing more until he further promulgates his ideas before the larger world of the Society of Arts, for which, we observe, he is down for the 26th inst. Before quite leaving the subject at present, we may notice that artists are and have long been in the habit of improving upon nature, especially as regards the human figure. We have heard Sir George Harvey, President of the Royal Scottish Academy, speak in approving terms of the action of the late Kenneth Maclea, who invariably when painting a photograph or using a photograph to mak an oil painting from it, drew the eyes larger than nature had represented them. Possibly it was this craze, so prevalent in former times, that accounts for the large goggle, saucer-like eyes to be found in so many of tlie ivory miniatures of by-past times. Whatever artists may say, and however much they may decry optical truth, there is no doubt that photography has conduced to a more accurate and healthy tone in their drawings. LENS SCREENS. It has been objected by thoroughly practical men that our recent suggestions as to the need of lens screens, especially in studio work, err on the side of unnecessary precaution, the ground our objectors take being that in their own personal experiences, covering long periods of time, they have produced thousands of negatives without taking any such care as we have stated to be needed, and yet have had no negatives spoiled by "lens fog."' Quite apart from the legitimate argument that a number of negative results do not necessarily invalidate an apparently sound logical predicate, it is enough to say that the particular conditions of every individual studio have to be taken into account before forming a judgment upon the subject at issue. Now, it is very easy to show that the position and construction of the studio itself may be such that a natural screen, if bricks and mortar may be so called, may exist. Thus, take in the first case a studio built upon a roof-ridge roof, lean-to, or other style, a lens screen is a nne-i/ud-non to the production of uniformly good results, for under many conditions of lighting the light must enter the lens from the sky or clouds, and frequently under such conditions will mar the otherwise attainable perfec- tion of result. Let, however, as is often the case, a studio— one worked from one end only-— be built against a lofty building, say, on the ground level in the gardens of a square, the sitter being so placed that his back will be against the outer building, there will be practically no need for the precaution of a lens shield, seeing that the building itself intervenes between lens and sky and so shuts out objectionable outer rays. We have thought it well to allude again to this subject and the objections brought against it, seeing that it affords an opportunity of emphasising our advice and further pointing out conditions that may render them unnecessary. That under the majority of circumstances a screen is highly desirable our arguments conclusively show, and we cannot too strongly or emphatically recommend every photographer not using one to look around and see whether he cannot better his results by adopting some plan of screening. If we thought our argument needed fortifying, it would be enough to point out that it is no new theory, for such screens are by no means uncommon among professional portraitists, though we laid stress upon the recommendation, knowing that they might with advantage become far less uncommon. Their forms are very numerous, every user of them having his particular views as to the most suitable construction. One of the most elaborate we have seen is the patent Lafayette camera stand, fitted with curtains and blinds. So complete are the arrangements in this that the camera itself is screened from the light, while provision is made for the lens itself to be hidden from external useless rays of light by the curtains of the stand, further aided by a spring-roller blind in front, which may be drawn down to any extent required to shut off" sky light; and this blind is still more increased in protecting power by two hanging side pieces for cutting off side light that might offend. The simplest form that has been brought before our notice is a provision for hanging black velvet over two projecting arms, swinging in sockets attached to the camera itself. Another good plan is a light wooden skeleton framework lined with velvet, and attached to a wooden support, which slides under the camera in grooves cut on the under side of the stand. This can be pushed in or out according to the conditions of light and the particular lens used. To describe all the expedients we have seen wo\ild need far more pages than are to be found in a whole number of this Journal. We have said enough to show the need, and to impress on those who have not before felt it the desirability of adopting some one or other plan to meet it. The same remarks apply to cameras for outdoor use. It may here be said that, seeing the great want of some plan of this kind for outdoor use, it is very unfortunate that we now never see lenses provided with the attached shutter, such as were fitted to the original Ross doublet lenses. These, it may be remembered, had an outside flap for use as a screen, and an exposing arrangement inside the lens. This use of the flap was little understood, and we have frequently seen the inner exposing arrangement always set open, and the shutter or flap used for making the exposure. It answered for that end, of course, and occasionally, at the same time, subserved its original purpose. But with the advent of dry plates and instantaneous shutters the sky shade seems to have dropped out of existence, the more the pity. Then, again, before the elaborate cameras of modern days, it was no unusual mode of construction to have them with a sunk front, which served both to protect the lens when the whole apparatus was folded and put away, and for use as a sky shade when landscape work was going on. It needs no instruction for any one to devise an arrangement, economical or elaborate, to provide a screen. There are abroad contrivances as numerous as those used by portrait photo- graphers. All we say is, let every one give careful thought to our arguments and carry into his daily practice the adoption of some scheme or other in which these recommendations will be embodied. The Photographic Society and Affiliated Socie- ties.— The recent revision of the rules of the Pliotographic Societv of Great Britain has resulted in the adoption of a rule which shoiiM greatly facilitate the ing-re.^s of members into the Society. In future, members of affiliated societies, who have belonged thereto for a perioil of two years, may be proposed for membership of the Parent Society on the nomination of their own Secretary, and will be admitted witli- out entrance-fee. April 21, 1893] THE BRITISH JOURNAL OF PHOTOGRAPHY. 243 Water-colour ZSxIxlbltloii.— The Exhibition of the Royal Water Colour Society, wliich opened on Sloflday last, is one that photographers, particularly those devoted to landscapes, will do well to visit. A large proportion of the pictures are just that class of subject that the majority of amateur photographers delight to render. A visit cannot fail to be profitable, as the photographer will see much to imitate, and, in a few instances, what to avoid. More Photogrraplis for Cblcagro.-- English photography in its various phases will, apparently, be well represented next month at the World's Fair. At the last meeting of the Astronomical Society it was mentioned that Dr. Ainslie Common had, at the request of the Council, produced a fine series of astronomical photographs for the Exhibition. The series includes a number of diagrammatic enlarge- ments of different solar eclipses with corona tliat will prove highly interesting to Transatlantic scientists. Every one is familiar with Dr. Common's astro-photogriiphic work, so there is no question that this branch of English photography will be represented at its best. The Photographers* Benevolent Association.— It is to be hoped that this institution will receive a good benefit from the Sandell Exhibition. It did from Mr. Fred Hollyer's recent Exhibition of platinotype reproductions of Mr. Burne Jones's and others' works. The Photographic Society of Great Britain annually gives the Asso- ciation a benefit night, and the Photographic Club did so once, and it is somewhat surprising that other Societies have not followed the example; for, by this means, the funds of the Association might be considerably increased. By the way, could not the Bene- volent Association get up one or two entertainments during the winter season, as it once did, on its own account ? There is con- siderable talent, both vocal and instrumental, in the photographic world, most of which would be forthcoming gratuitously for so deserving an object. We commend the idea to the Committee, although it would be too late to carry it out this season. Success of Societies. — Xotwithstandins the number of Photographic Societies that have sprung into existence during the past few years, the majority of them are in a flourishing condition. The annual report of the South London Photographic Society shows that it has lOo paid-up members. This is many more — probably double— the number that the original South London Photogi'aphic Society possessed in its palmiest days. Yet the old Society pre- served an active life for more than a quarter of a century, and its meetings were well attended by experienced workers. The roll of members cannot be taken as a criterion of the activity of any Society — it is by the attendance at the meetings, and the business transacted, that an opinion must be formed. For example, the original North London Photographic Association, if we mistake not, had something like 120 paid-up members at the time of its decease. It died of inanition — the members took but little interest in the meetings. The new South London .Society is to be congratulated on its membership and the attendance at its meetings. The Eclipse of the Sun. — The total solar eclipse was ob- served at Para Cura, on Monday, under favourable conditions by the British astronomical expedition under the charge of Mr. Albert Taylor, assisted by Mr. AVilliara Shackleton. The clouds were heavy shortly before contact, but afterwards dispersed, leaving a clear space for observation during totality. The photographs taken are not yet developed, but are believed to be satisfactory. Professor Pickering, of Harvard College, states that the atmospheric conditions prevailing at Minacaris during the solar eclipse were perfect, and that the results of his observations were very satisfactory. Professor Pickering says that he observed four streamers proceeding from the corona, two of which stretched over a distance of more than 4.'!5,000 miles. Several dark rifts were also visible, extending directly westward from the moon's limb to the utmost limit of the corona. Several solar promi- nences attained freat distinctness and brilliancy. During the eclipse the surface of the moon appeared almost of an inky blackness by con- trast with the dazzling brightness of the inner corona. The observa- tions, I'rofessor Pickering remarks, showed very conclusively that the present condition of tiie sun is one of great disturbance. There were very distinct evidences of a large number of spots, and of the presence of faculm. The corona was whitish rather than red in tint. The results obtained may be said to be a combination of the observations, as drawn by Liais, of the eclipses of 18(57 and 1871. The photographs taken on the present occasion. Professor Pickering concludes, were both numerous and satisfactory. aichmond Heads — a Novelty. - Just now portraitists are on the alert for anything in the form of novelty to give a fillip to business during the coming .season. We were recently shown some portraits that possessed great artistic excellence, and, although the style was by no means new, it, under its present aspects, was certainly novel, hence our allusion to it. The portraits were vignetted heads, cabinet size, by the platinotype process, but, instead of the figure being merely shaded off in the usual way, some delicate hatched lines were introduced in the vignetted portions of the figure and the background after the manner of Richmond's celebrated heads. This destroyed much of the photographic appearance of the picture, and gave ita close resemblance to a chalk or crayon drawing, particularly when it was on moderatelj- rough paper. As we have just remarked, the style is not new. It w.is introduced by Mr. N. Sarony for carfes-de-visite, and patented by him something like thirty years ago. It did not take then, probably because the crayonli'ue hatching on such small pictures on highly glazed paper was quite out of keeping. But with larger sizes on a matt surface, as in the platinotypes referred to, the effect is widely different. There are many ways by which the hatching can be introduced, such as that of Sarony by a double exposure in the camera, first to the sitter and then to a liatched background, double printing, using a vignetting glass upon which the lines are etched by fluoric acid, or with the lines scratched on a plate coated with black varnish. la the present example, the hatching was introduced by a second printing from a negative made from some artistically hatchf d lines of larger ^ize ; indeed, from one of the lithographed backs that used to be supplied for the old photo-crayon portrait. Graver versus Process. — It is always well to look an adversary squarely in the face. This is th-i attitude that was only slightly taken last week at the first aimual dinner of the International Society of Wood Engravers by Mr. W. L. Thomas, R.I., who presided. While it is quite true, as he observed, that the much-threatened art of wood-engraving has never been more worthily upheld than by the engravers of the present day, and that a fine engraving of this class lias an inexpressible charm about it, still we know that process work has made fearful havoc among the ranks of wood-engravers — a havoc that is constantly increasing, witness the numbers that are being compelled to retire from that profession in consequence of the rapidly advancing tide of •' process." But since the times of Palmer, who was the first to strike a blow at wood-engraving, process work has undergone a revolution, which dates from the time that photography has been impressed into the service, for not till this was done was there any real danger to the profession. Over a quarter of a century has elapsed since, apropos of the Graphotype process, which was then being introduced, we published an article entitled " A Blow at W^ood- engra\ing," which led to some far-seeing engravers taking just alarm at the prospects of their profession, and providing against a possible further development of that encroachment ; yet did the danger from the source named pass away with the failure of the Company that worked it and controlled the patents. It is really the Gillotype, or its congeners, for line work, and the grated screen system for half- tone that have imparted the most severe blow yet given to the wood- engraver, and these processes have come to stay, and will eventually oust skilled hand work from its strongholds, at any rate, from the important position it has so long occupied in relation to serial and book illustration. The time has now passed when wood-engravers can afford to treat photo-proiess work as " a foeman unworthy of 244 THE BRITISH JOURNAL OF PHOTOGRAPHY. [April 21, 1893 their steel." AVe know of numerous draughtsmen who are producing their drawings ^v-ith special reference to their being engraved by process, and the encroachment cannot afford to be ignored. It may be remembered that a hostile attitude was taken against portrait photography by miniature painters some forty or fifty years ago, but photography eventually proved to be too strong. . — ♦■ RESTORING FOGGY PLATES. A SHOni time back, in turning out a box that had not been unpacked for several years, and which was supposed to contain only books and papers, I came across a packet containing some dozens of dry plates, which had been entirely forgotten during all that period. From the memoranda on the various packages I found that the plates were all over ten years old. some of them nearer twelve, having been made at various times for experimental purposes ; and from other data I have to go by I know that most, if not all of them, contained a certain proportion of chloride in their composition, while many also contained iodide. I had, however, nothing to guide me, except in one or two instances where the information was pencilled on the packet, as to their precise composition, but I take it that they were all either bromo-chloride or bromo-iodo-chloride films. An examination showed that they were all more or less— some Tery badly— affected by iridescent markings round the edges, a fault which has been said, with what truth I cannot decide, to be a necessary concomitant of the employment of chloride. On submitting some of them to development, the worst cases were found to be hopelessly ruined by fog, while others, though comparatively free from heavy fog, fell far short in quality of what a modern plate of even moderate character is expected to be. The greyness and veiling of the image was in all cases accompanied by a poorness and difficulty in obtaining density that rendered the plates quite useless for practical work even when giving a fairly clear image. I tried every possible means, by ringing the changes on modifica- tions of development, to overcome the tendency to thinness, but with- out any great degree of success. But I may say here, in passing, that our old friend, pyro, once more proved itself a more trust- worthy servant than any of its newer rivals, for no modification, either "in strength or otherwise, of bydroquinoue, eikonogen, amidol, or para-amidophenol, produced the slightest improvement. With pyro, however, on increasing the strength to about six grains to the ounce, printing density was obtainable with some of the better samples ; but this, unfortunately, was accompanied by an increase in the veil or fog that practically nulUfied the advantage gained. It so happened that I ran out of plates of a particular size for some work I was doing at home, and, as there were some of that size amongst the defective ones, I resolved to try if they could not be restored to workable condition. From the fact of the plates having been packed away, instead of going to the " wash-tub," I conjectured that they had at one time been of good quality, and indeed, except for the iridescent edges, they appeared all right even now, being rich and dense in character; indeed, from a knowledge of the formuhe I was in the habit of employing, I knew they contained a liberal quantity of silver, if it could only be brought into available condition for use. The first attempt at renovation was made with a plate of medium character, neither one of the worst nor one of the best, but picked out almost hap-hazard, since I concluded that, if the treatment answered for one, it would for all, in which it subsequently turned out I was correct. A solution was made as follows : — Bichromate of potash 2 drachms. Bromide of potassium 1 drachm. Water 10 ounces. In this the plate was immersed in a dish for five minutes, and then it was carefully rubbed over, especially at the edges, with a fine and very soft Turkey sponge, rinsed with water, and returned to the bichromate solution for another two or three minutes. It was then copiously washed from a jug and left to soak afterwards for an hour, face downwards, in a basin of water, the latter being changed some half-dozen times during the interval. It was then taken out, drained, and exposed wet, a comparatively long exposure being given, and on development it turned out as good a quality of negative as could possibly be desired. The loss of sensi- tiveness brought about by the treatment, too, had been over-estimated, for, though not over-exposed, a shorter time would have sufficed. The next experiment made was with a view of improving the sen- sitiveness, for which purpose the plate before exposure was immersed for three minutes in a weak solution of ammonia — three minims of strong liquor ammonias to the ounce of water ; but, though this had the desired effect so far as it brought the sensitiveness back to about that of an " ordinary " gelatine plate, it reintroduced a slight tendency to fog, which without the ammonia treatment was conspicuous by its absence. As the work I required the plate for did not necessitate any great rapidity, the ammonia was relinquished for the time, though as I shall show, I later on succeeded in securing the extra rapidity without the addition of fog. The process of restoration as thus conducted was all very well under- the circumstances, where the plates were wanted, and it was the only way of getting them ; but it was an eminently tedious one for ordinary use, and, of course, entirely out of the question for outdoor work. So I set to work to [improve upon it by removing the fog and restoring the plates to the dry condition, so that they might be available for any purpose whatever. The films as they stood consisted of gelatine with a mixture of silver haloids and probably some unremoved soluble matter that had assisted in bringing about the deterioration, though, no doubt, the silver chloride they contained contributed more than anj-thing else ta the result. The action of the bichromate solution is primarily to remove the fog and next to convert the chloride of silver into bromides- while the various washings the film has to undergo further bring about the removal of any soluble matter. Therefore it seemed reasonable to anticipate that, if the plates were treated as already described, washed with sufficient thoroughness to remove every trace of bichromate and dried, the result would be not only films that were usable, but that would keep owing to the elimination of the dele- terious agents that had led to the previous deterioration. I need not enter in detail into the various e.xperiments that led up to the final method adopted, but will briefly describe the process as completed : — The plates were treated eighteen at a time in rack, holding that number, being dipped first of all into a tank containing the bichromate solution, in which they remained five minutes. The sponging of the individual films may be resorted to, but I came to regard it as an unnecessary refinement, and relinquished it. The racks were transferred one by one to a large tub of water, each re- ceiving the contents of a large jug of water to remove the large excess of bichromate solution from the plates and rack. Living, as I do, in the country, though I have unlimited water supply, I have not the facilities for keeping up a constantly changing current, and must therefore rely upon periodical changes, which necessarily prolongs the time occupied in the process. However, by drawing off and replacing the water once every half-hour for a couple of hours, I found, with the volume employed, that the bichromate was practically eUminated : but, with a constantly changing stream, it would be, no doubt, removed in a much shorter time. As the treatment with ammonia for restoring sensitiveness had proved a failure, or pai-tially so, I cast about for a better plan, and succeeded at last by imitating as nearly as possible the condition that prevails in the sensitising of an emulsion by the " ammonia pro- cess." Here the silver haloids are subjected to the action of ammonia, not alone, but in the presence of excess of soluble bromide and of the by- products produced in the act of sensitising, in other words, nitrate of potash or of ammonia, both of which act as fog-restrainers. This gave me the "tip" for the next part of the process. After a couple of hours wasliing the plates were transfened for half an hour to a solution composed as follows : — Liquor ammoniie 2 ounces. Bromide of potassium 1 ounce. Nitrate of ammonia 2 ounces. Water 40 „ This, while adding to the rapidity of the films, further ensures th» total removal of the bichromate, the slightest trace of which allowed to remain would be fatal to sensitiveness, and, if present in any quantity, to development, except in the best lighted portions of the- Alpnl 21, 189a] THE BRITISH JODRNAL OF PHOTOGRAPHY. 345 image. Altlioujfli for actual working purposes it is not «o absolutely necessary to remove every trace of the above solution, still it is most desirable it should be done ; and, indeed, if the plates are to be kept for aiiy length of time, it really is needful. A preliminary rinse, followed by a soaking of half an hour in three or four changes of water, will do all that is necessary. All that remain.s now is the drying, which may be effected by simply re.sting the plates on end on a few thicknesses of blotting-paper in a dark cupboard or a lai-ge packing-case. Films of ordinary thick- ness will thus dry perfectly in less than twenty-four hours. But to ensure perfect regularity of drying, and also to materially hasten it, I prefer to remove the superfluous moisture from each individual tilm by one or other of the following means : — I prefer to use a sort of roller squeegee, formed of a wooden roller mounted in a handle in the usual way, and covered, first of all, with several thicknesses of blotting- paper, round which is finally woimd, for two or three times, a short length of soft, o/il linen, neatly sewn, so as to leave as little ridge at the edge as possible. Before using this, the plates are allowed to drain for a few minutes until they become nearly surface dry ; they are then taken singly, laid on a flat surface, and the squeegee passed over them with considerable force or pressure, which will squeeze a good deal of moisture out of the film, and leave the surface perifectly even. Failing the squeegee, a thick pad of blotting-paper faced with soft linen, free from " fluff," will answer the purpose very well ; it is simply laid on the plate on a flat surface and rubbed with the hand with considerable pressure. After either of these methods of treat- ment, the films will dry with great evenness in a few hours. I have mentioned this method of restoring plates, firstly, because by its means or similar I have not, for the first time, been able to utilise otherwise useless films ; but, secondly, because it may frequently prove of value to either amateur or professional who may have the misfortune to light upon a bad lot of plates. I have, for instance, only to-day made a good negative on one of a batch of commercial plates that have hitherto puzzled me entirely. The trouble involved is really very little, although it may seem so in description, for, with fairly convenient washing arrangements, three or four dozen plates may easily be treated in an evening and left until next day to dry. The quality, moreover, is scarcely to be surpassed by the best com- mercial plates now on the market. 1 omitted to say in connexion with the sensitiveness that, although I have not obtained— for I have not really tried— the rapidity of the quickest commercial plates, yet the films I have restored are quick enough to be used for groups and animal pictures, using /-ll, and taking the cap off and on as rapidly as possible. No doubt still shorter exposures would do, but I have not tried them. W. B. Bolton. JOTTINGS. Thf weather recently has been phenomenally fine and genial in this country — except in the vicinity of Sydenham, where, according to all accounts, it has developed Siberian severity since Monday week. The wintry visitation gives every indication of lasting till April 29, when a change for the better may be expected, consequent on the closing of the National Photopfraphic Exhibition on that date. Th* photographic press is unanimous in characterising the apparatus section of the Crystal Palace show as a fiasco. On the principle of evil coming out of good, the trade, the dealers, and the manufacturers are to be congratulated at standing aloof from the Exhibition, and the moral of their action, it is to be trusted, will not be lost on organizers of future exhibitions who may be blind to the fact that they do not possess the confidence of those they aspire to represent, or who shut their eyes to their own unfitness for the task they under- take. Such is the vanity of photographers, that it is not difficnlt in these times to get up a large and fairly good exhibition of photographs, but business men do not a? a rule give way to the pleasant vice unless there is money in it, so that it is becoming increasingly difficult to get up a good apparatus show. I throw out the suggestion, that any future exhibition of photographic apparatus, on a large scale, should be managed by the trade, and for the trade. It is a matter that might well have fallen within the province of the defunct trade as-sociation, in collaboration with a small committee of photographers charged with the care of the pictorial department. I read in an American photographic journal that the Camera Club have forbidden the English photogruphic press from reproducing ])apers read before the Club and published in its Journal. Strange to say, in others of the American papers issued at about the same time as the one I have referred to, I came across several Camera Club papers printed in full. The Club, I suppose, can do what it likes with its own, but I wonder whether the ukase meets with the approval of readers of papers who are thereby prevented from iiddressing on occasion the photographic world at large, of which the Camera Club, much as I respect that body, is, after all, only a trifling fraction ? The action of the Club, which finds no parallel in any learned Society, from the Royal Society, of which the Club's President is a Fellow, down, is explicable on two grounds alone : First, that the photographic pabulum served up at Charing Cross- road is too intellectual for the vulgar photographic public, in which case I hope the legislature will at once pass a Bill making it penal for anybody not a member of the Camera Club to pretend to know anything at all about photogi-aphy ; or, second, that the said photo- graphic pabulum has got too ridiculous for reproduction at the hands of charitablj- disposed editors anxious, as far as possible, to give everybody a hearing in their pages, so that the Club are simply protecting the readers of papers against themselves. In this case, let us be grateful for small mercies, and say, The Lord be thanked I I see it stated "that, if a platinum print be very much over-exposed so that all the details are out, a good result comes by fi.xing in the acid bath without developing." Granting the accuracy of this, have we not here the germ of a simplified process for platinum printing ? I draw the attention of Mr. Willis to it in the hope that he will make a note of it. I suppose the presence of moisture would be essential for obtaining the necessary quantity of reduction product, unalterable in dilute hydrocliloric acid, and that it would consist of a mixture of platinum and iron. It is a great pity that when these interesting communications are conveyed to us they are not accom- panied by some attempted explanation of the phenomena observed and the conditions prevailing. I have tried platinum printing accord- ing to the method described, and could get nothing but a faint image, looking more like a stain than a deposit. I beg to ask Mr. H. VV. Peal, the President of the Ealing Photo- graphic Society, who read a paper on Copying Engravings and Drawings before the West London Society on March 28, and which is given in the Jouhnal of April 7, upon what experimental evidences he bases the statement that amidol enables a photogi-apher to do with one-third of the usual exposure? I am well aware, from practical observation, that a plate is frequently found to be faster to one developer than another — a fact which is easily conceivable by any one having the slightest acquaintance with the physics of emulsion- making — but, until it is proved to bo the case, I refuse to believe that there is any known developer combination in current use which, all else being equalised, will allow of the photographer reducing his usual exposures two- thirds. Think, Mr. Peal, how nice and con- venient for the portrait man it would be if he could give studio ex- posures of two and three seconds instead of six and nine, simply by substituting amidol for pyro ! lie can't ; take my word for it. Ditto to you, " Drop Shutter ! "' What possible object a Hand Camera Club can serve, beyond contributing a more or less appreciable addition to the pretty little game of you-scratch-my-b.ick-and-I'll- scratch-yours, which is such a marked feature in photography- nowadays, I'm afraid very few people could tell, even in a prize- gues.sing competition. There are too many photographic Societies as it is. Every parish, as " Drop Shutter" points out, possesses one ; and to ask us to believe that adequate facilities are not afforded in the broad kingdom of hole-and-cornerdom which those Societies occupy for talking about the hand carnvra and all that appertains thereunto. 246 THE BRITISH JOURNAL OF PHOTOGRAPHY. [April 21, 1893 is to draw an uncommonly big bill on the credulity of the photo- graphic public ; for, after all, I fear the hand camera " is a thing of beauty and a toy for ever " with most of those who use it, and who have neither the capacity nor the desire of completing their photo- graphic education. It will be found, I believe, that the few good hand-camera workers we have are in other respects capable photo- graphers, and for them there are plenty of Societies where they can secure opportunities of listening to their own voices. According to the published reports, that is about all for which moat of the photo- graphic Societies are useful. "Sweet Spirits, hear my Prayer." This would have been an appropriate sentiment for Mr. Traill Taylor when that gentleman was maliing his now famous experiments in psychic photography. I wonder if, in the midst of the subsequent alarums and excursions which his paper has provolted, he has been inclined to parody the line and mutter, " Sweet Spirits, hear me swear ? " Whether they heard him or not, you couldn't blame him if he did use a big, big D or two, could you? Cosmos. RETOUCHING. pJewoastle-on-Tyne and Korthem Coanties Photographic Association.] I FEEL I must not begin to-night without offering a sort of apology for the brevity and the incomplete state of this paper. I would fain have got off altogether, but have not dared again to mention it to the Secretary, as he has already let me off once before. It was my intention to have prepared examples and slides to illustrate it, but I have really had no spare time to devote to slide-making, having been so fully occupied with business lately. On some future occasion I hope to be able to give a more complete and comprehensive paper, with lantern-slide illustrations. Retouching is the art of improving or doctoring a negative or positive by the aid of a lead pencil, or by the use of a sable brush, and not, as a certain writer on so-called naturalistic photography would have it, when he says it is a process by which a good, bad, or indif- ferent photograph is converted into a bad drawing or painting. Now, I cannot agree with that in the slightest degree. I do not mean to say but that there are many instances where a good negative, without any retouching whatever, would give a finer print than if it were given into the hands of the most competent and experienced re- toucher. Retouching, like many other things, is an operation which is very much abused, and has been overdone to an alarming extent. It has been said many times that some operators depend entirely on the skill of the retoucher, caring very little whether his subject is well or badly lighted, thinking all will be put right by the retouching. Now, this is perfect nonsense, for, unless a good and well-lighted negative is put into the retoucher's hands, all the skill and artistic knowledge he possesses will not enable him to make it into a perfect negative. Certainly a badly lighted and defective negative may be considerably improved by judicious retouching and careful printing. Some recommend thin and weak negatives as being the best ; others, again, strong and denser ones ; but from experience I find that the best results are got from negatives that are all round good, both in lighting and everything else. It is, no doubt, true that retouching — • that is, a certain kind of the work — has done much harm to photo- graphy, and, unless the operator and retoucher work in harmony together, each striving to get the best possible results, the standard of retouching is considerably lowered. Retouching is a branch of photography which an amateur does not often attempt. In working upon the negative with the pencil, one of the greatest difficulties to amateurs and beginners is to be able to obtain texture, a process by which much time is generally wasted, and the result very often disappointing. He tries to get a good result, but without knowing how to go about it. I think amateurs are often much puzzled by a too elaborate description of how to do this and how to do that ; whereas, if the thing was put in a more practical form, many would be better able to accomplish more in the way of such operations as retouching and improving the printing qualities of their negatives generally, than they would with such impractical instructions. It must not be supposed that retouching can be learnt easily by taking a course of lessons, no more than drawing or painting can, but can only be attained by careful practice and experience, and the ex- amination of good examples by first-class men. I just intend giving a few verbal instructions to amateurs present, which are in no way tended for any professionals who m ay be here to-night. Th e simplest method of all is the working on the back of the negative and often a very great improvement can be made by doing so, especi- ally in the case of much heavy shadow and want of detail. There are various methods of preparing the back of the negative. A fine quality of tissue paper or, better still, an oiled paper called papier minirale, pasted carefully on the back, and, when quite dry, worked over lightly with the pencil on the parts that are too transparent, at the same time cutting out those parts that may be already too dense. I have seen a harsh printing negative yield a very good print after such treatment. This answers as well for a landscape as a portrait, and is what I frequently do in practice. If a negative is too weak and wanting in contrast, the higli lights can very easily be strengthened by stronger lines with a soft pencil, or crayon can be used. I believe, some years ago in America, the use of both black and red crayons was recommended for certain kinds of work, but I do not think with much success. Crayon powder is sometimes useful, but more diflicult to work. I find, if there is only very little work re- quired on the back of a negative, it is quite sufficient to give a light wash of madder brown in water colour, with a little gum added, on the gla.is itself. It may seem a difficult operation to spread an even wash of colour on glass ; but it is not so, requiring very little practice, only the glass must be perfectly clean and the colour" free from grit or dust. In a landscape clouds can sometimes be worked over a thin sky so as to be passable, but I would rather recommend blocking out the sky entirely and printing from a cloud negative. Working with a pencil on the film side is not such an easy matter for the beginner. For this a retouching desk is necessary, which is a piece of apparatus- needing little or no explanation. It must have a piece of very finely ground glass, or the coarseness of the grain will be visible through the negative, and will confuse the retoucher. I also would explain that, if the negative be raised up from the ground glass to the extent of about an inch, leaving a little space between the negative and the glass, the grain is destroyed when the eyes are focussed on the part to be worked upon. I may here give a word of caution with reference to the eyes. On no account practise retouching if your eyes are not strong or suited for it, as the injury done to weak eyesight by persistent retouching, with a strong light on them, is considerable. A good plan, if the eyes are weak, is to cover the reflecting mirror with white paper, which gives a very soft and pleasant light to work by, unless, of course, the day is dull. Some use a magnifying-glass for small heads, but that I don't recommend, as the point of the pencil is also mag- nified, and very awkward to use in consequence ; the natural eyesight is preferable, if the eyes are strong enougn to bear the strain. With regard to the surface for retouching upon, it is necessary to roughen or abrade the bright surface, so that the pencil will bite. There is great difference of opinion with regard to the proper kind of surface ; some prefer using a matt varnish, others prefer rubbing the part with turpentine or powdered cuttlefish bone. There are many other methods of preparing the surface so as to give a tooth to the pencil. I have tried almost all, but cannot find anything better or simpler than powdered resin, applied to the part with the tip of the finger and dusted off with a flat camel's-hair brush. In the dajs of the collodion negative, a little very fine coal ash, rubbed on very carefully, gave an excellent surface for working on, but great care was required to avoid damaging the delicate film ; with gelatine plates it is quite different, as it is surprising what an amount of rough handling they will stand, without damage. The pencils are an important item in the retoucher's outfit. The best for the purpose are either Faber's or Hardtmuth's; HB, HH, and F are the most suitable, although I have known four and six H's to be recommended, which is very absurd. The pencil must be sharpened to a fine point, and, as it wears away quickly, it must be kept in condition by rubbing it gently on very fine emery cloth. The be.st way to use the emery cloth is to glue a narrow strip on a piece of flat wood. In bnginning work at the desk, sit in an upright position ; do not bend or stoop over the work, do not look too closely at the negative, unless you are short-sighted ; a far better effect is got by working at a little distance ; you will find it more comfortable, and not so tiring. Before commencing to retouch a head, it is advisable to take a rough print from it, although it is rarely done by the profession. Now comes the most difficult part, the actual retouching. If the negative has been properly lighted, a correct exposure, and carefully developed, the work will be quite easy, unless the subject is muck, marked with freckles, in which case it requires a certain amount of skill and patience to remove them. It will be best seen from an examination of the rough print what is required. Many spots and blemishes will be seen which really are in the subject's face, but con- siderably exaggerated in the [photograph ; to get rid of these and. April 21, 1893] THE BRITISH JOURNAL OF PHOTOGRAPHY. 247 soften strong shadows, without in any way losing the likeness, is tlie work of the retoucher. Different faces require different treatment; old faces may be worked over without in any way altering the character, but still may be improved. Some faces are patchy, which would bo unwise to leave so ; the patchincsa must bo removed, whicii will not affect the likeness, but will give a more pleasing expression. Children's faces require very little work, unless much marked with freckles. In the faces of young ladies and gentlemen tliere should be no very strong lines or wrinkles. About the mo3t difficult faces to do, to give satisfaction, are those of middle- aged ladies. The majority of lady customers say nothing about wanting to be flattered, but it seems to be an understood thing that the photographer is to do his best in that way. Of course, there are exceptions. One lady gave me special instructions to touch out all lines and wrinkles, and to make her look as youthful as pos-ible. Only once, I think, have I been asked to do it, and only once have I been requested by a gentleman not to touch up his photograph at all — he wished to come out just as he was, as Oliver Cromwell said, warts and all. But I did touch him up, and he was perfectly satisfied. When commencing a head, the better plan is to give it a general clean up, get rid of all the defects first, and soften shadows and lines that are too strongly marked. Do not fill in all shadows alike, or a flatness will be the result. Rules cannot be laid down as to the movement of the pencil. Almost all workers have a different style of their own, some working with certain comma-like strokes ; others, again, in small circles, in straight lines, in cross hatchings, and a variety of other ways. I prefer partly cross hatching and a sort of zigzag rubbing motion as being as good as any other. Delicacy and freedom of touch can only Tje acquired through practice and experience ; strokes of the pencil should run in the direction of the muscles as much as possible. I re- member many years ago, when retouching first came into general use, some of the heads done in the " Berlin " style, as it was then called, looked more like a person who had had a very bad attack of small-pox, .so coarse was the grain on the face. There are many who condemn retouching altogether, and no wonder when we see such attempts as we often do in every-day work. Some faces are covered with white spots, others are like sand- paper ; children, old men and women are all made alike. Others, again, are in favour of it, and, I think, rightly so,many photographers using it only as a necessary continuation of good and careful work. I think a good retoucher is as useful a member of the photographic profession as any other, and I think, if amateurs would devote a little time to retouching, their negatives would be sometimes much im- jiroved by it. "William Pahry. SOME NOTES ON NATURALISTIC PHOTOGRAPHY. [Photographic Society of Ireland.] My excuse for giving a paper to-night on a subject so much debated already, and one having given rise to so many violent and wordy contests, is the fact that Dr. Emerson has come forward once again from his retirement as the champion of his old ideas on art and their adaptability to photography. In fact, in his recent paper read before ■the Photographic Society of Great Britain, he takes up, with very slight modifications, the doctrines he taught in " Naturalistic Photo- ^aphy.'' There can be no doubt that the first feeling his reappear- ance gave rise to was one of genuine pleasure at his return to the photogi-aphic fold. I must confess that I strongly feel what an advantage it is to have on the side of photography one so enthusiastic on the theories of art, and possessing a large amount of artistic taste combined with a practical knowledge of photography. There can be no doubt that " Naturalistic Photogi'aphy " has done an immense deal of good to photography ; there are certain principles laid down in it, there are ideas suggested that have revolutionised our art, and, in fact, have created a new school ; and it is a strange fact that in several instances the pupils have produced very superior practical results to their master in carrying into effect his principles. Having thus freely expressed how much I appreciate the teaching, theoretical and practical, of Dr. Emerson, I will now, with equal libertj', say how thoroughly I am at variance with many of his theories, assertions, and criticisms, which are marked with an extra- ordinary narrowness of view and an absolute want of appreciation of the position taken up, or of the arguments advanced by, any one hold- ing views opposed to his own. Nothing is more conspicuous in his writings than his absolute want of judgment. He poses above all as a cntic, and yet he cannot even correctly judge his own productions. In liis book, Naturalistic Photography, his first and truest merit is, that he saw clearlj^ ond boldly advocated the high pocition that photography had a right to claim amongst the methods of pictorial representAtion. Could this be better expressed than when be says : " I'hotography may be, and is, in the hands of an artist, a method of expression producing works of fine art, because no such worlu can be produced in photography by a man who is not an artist." And, again, " Photography stands at the top of the second or tone class of methods of expression, so nearly perfect in its technique that in some respects it may be compared with the third or colour class. The scale here, too, is limited, but le.ss so than that of any other black and white method. Its drawing is all but absolutely correct — that is, if the lenses be properly used. It renders the values relatively correct if orthochromatic plates are used, and it renders texture per- fectly!" The first passage occurs at page 17 of the work, the second at page 277, so we may say that, from beginning to end, his book is an eloquent pleading in favour of the claim of photography to a high place in pictorial art. In this respect the only fault to find with the author is that perhaps his enthusiasm makes him go a little too far, for, much as I love and appreciate photography, I feel that it has serious limitations which can never be removed. It was, no doubt, the consideration of these limitations, and par- ticularly those connected with perspective and the altering of ratio in development, that brought about Dr. Emerson's renunciation, wliich renunciation is, however, for all practical purposes, itself re- nounced in his latest paper, for there we read : " I may now say the methods of practice I advised in naturalistic photography I still ad- vise, and the artists I held up for admiration in that work I still hold up as the best examples of their various crafts; but my art philosophy is different, and I do not consider photography an art." The difiiculty about perspective is settled by the admission that the opticians are right from the mathematical standpoint, and he was right from the physiological and psychological standpoints. Of Messrs. Hurter & Driffield's theories on development, on which he laid so much stress in the renunciation, there is not a word in his latest utterance. Dr. Emerson's art philosophy, when it deals with pure theory, is often very hard to follow ; it consists too often, as Mr. A. Pringle aptly said in the discussion that followed the paper, " of a num- ber of truisms as old as the hills and a certain amount of extremely debatable matter clothed in high-flown and enigmatical language." The principal point where his latest theories lead him to differ from liis former opinions is the denying to photography the title of art, and to photographers that of artists. To me the whole thing seems a mere question of words and defini- tions, for when he admits that " photographs are worth doing if well done, because they give us certain beautiful qualities art cannot give, and that the producers of such may prove themselves as keen seers of the beautiful as the master artists themselves, and they may have art knowledge too," I think it matters very little whether Dr. Emerson calls them artists or photographers. You might just as well dispute over the question whether a man should be called an artist or a painter. Again, the so-called difference between mathematical per- spective and physiological perspective seems to be a distinction with- out a difference. There is really but one perspective, which is ruled by the mathematical laws which govern the correct rendering of different solid objects in different planes on a flat surface. The shapes and sizes of objects thus depicted may appear distorted, altered, or exaggerated from being taken from a point of view from which we do not usually see them, or even could not actually see them, and from which an artist would never take them, becau.se, as Dr. Emerson rightly says, a photograph, or a picture, must be " true in fundamen- tals to the point of illusion.' Speaking practical photographic language, this means, we should use as long-focus lenses as pcssible, 'so that no object in a picture should strike us as looking different to what wo see it in nature. The painter has the advantage of being able, in case he cannot change his standpoint actually, to be able to do so mentally, and thus render the objects at the same time true to mathematical perspective, and yet so little at variance to the way we see them as to produce the desired illusion. Of course, some painters have purposely altered the true perspective to produce certain effects, but these are exceptions that only prove the rule. The e.xample Dr. Emerson refers to — a man's boot being twice as big as his head — means, I presume, his own pictures, entitled, The Barley Harvett, and The Basket-niaher, and I think any ordinary photographer would tell him that, if he had used a longer-focus lens, and taken his picture from a greater distance, the difference of size would hardly have been noticed. Indeed, Dr. Emerson so well understands this, that he hails with delight Mr. Dallmeyer's new tele-photographic lens, and its length of focus is the only advantage it possesses for artistic work. Used to its full power — as in taking the pictures exhibited last season in London — it could scarcely receive his praise, for a pictaie 248 THE BRITISH JOURNAL OF PHOTOGRAPHY. [April 21, 1893 taken under the conditions described in the Exhibition catalog-ue would seem very different to anything he ever suggested. The fol- lov^ing is the description : — " Mont Blanc, at a distance of iifty-six miles ; smallest stop ; extension of camera, sixty inches ; seven minutes' exposure ; windy weather." There, everything is pretty well the opposite to what Dr. Emerson recommends in the practical part of his work. Having now placed before you the position assumed by the author before and after wliat he calls his renunciation, and having, I think, made it pretty clear that it is in point of fact unchanged, I wiU now examine what are his methods of teaching, and what is the practical outcome of this teaching. In his last paper he would seem to reduce his influence on photo- graphic art theory and practice to the discovery by him of the fact " that the closest truth to nature in photography was to be obtained by throwing the background of the picture out of focus to an extent that did not produce destruction of structure, the principal object of the picture being either sharp or just out of the sharp." I think if he had said that this was the hase from which he started to edify the structure of Naturalistic Photography, he would have more cor- rectly stated his position. It was certainly no new discovery to find out that the background of a photograph should he less sharp than the foreground, nor was it quite new to assert that even the fore- ground might be part out of focus and yet produce good results. The first was taught by a large number of landscape photographers, the second had been practically demonstrated by Mrs. Cameron and some other portraitists, and the producers of pinhole photographs. The merit, then, of Dr. Emerson's book is not that it gives us these facts for the first time but that, starting from the beginnings of art, it traces up the gradual development of naturalistic feeling in the works of the painters of every age, till it culminates in the modern French school of landscape painting as represented by Rousseau, Corot, Daubigny, Trojon, J. F. Millet and their followers, whom he holds up as models for all times and all men. Perhaps the hardest thing in all this writing is to find a definition of this natu) alistic feeling ; the nearest thing to it is where the differ- ence is desciibad between realism and naturalism (p. 24). " The realist makes no analysis; he is satisfied with the motes, and leaves out the sunbeam. He will, in so far as he is able, paint all the veins of the leaves as they really are, ard not as they look as a whole. For example, the realist, if painting a tree one hundred yards off, would not strive to render the tree as it looks to him from where he is sitting, but he would probably gather leaves of the tree and place them before him, and paint them as they looked within twelve inches of his eyes, he might even imitate the local colour of things them- selves ; whereas the naturalistic painter would care for none of thes3 things, he would endeavour to express the impression of the tree as it appeared to him when standing a hundred yards off, the tree taken as a whole and as it looked, modified as it would be by various phenomena in accidental circumstances." Having examined the history of art from this one standpoint — and I fear sometimes grievously misjudged it, as men will do when they try to judge things with one preconceived idea — having shown us his ideal in art, he devotes the rest of the work to demonstrating how photography can to a great extent be moulded into the form of this ideal.^ Now, this seems to me the strong point of Dr. Emerson's teaching, for it at once raises tha status of photography from that of a mere inechanical device for copying nature to a graphic art for reproducing nature with a personal modification, as far as its limited means allow. _ The chapters which follow on the phenomena of sight and art principles derived therefrom are highly instructive. We must not, however, forget that when, in examiu'ihg and describing tbe functions of the eye, we compare it to a photographic camera and lens, that we must not for a moment think the view we perceive, admire, and wish to reproduce, if we possess artistic faculty, is simply the miniature representation thrown on the retina as on a ground glass ; it is the image as translated hv the brain in its full size and proportion, in all its aerial harmony and natural solidity. I think this explains in a great measure the object of throwing a picture out of focus and n.^ing rough surfaces for printing, which gives an impression of size and texture as seen in the mind better than the inic.roscoiiic dcfinitiun of a lens or a very smooth surface. The chapters on the practical part of photography are good .and useful, but contain little that is new except the part on focussing, which expi-estes its author's well-known opinion and which many are too apt to associate with his name, to the exclusion of the teachings thnt have led up to it. In this pH(t (if 1 he work occurs his strong advocacy of grey day fflt-cr* nn 1 a ^-Hii^ml pff.'u-nee for gl-'om and hnziness c"iver sunshine, lj.ij;Liiitrtj, ui.d Wa.ii-tu. Ti,i.- nuy, 1 think, h^ trdccd to two cause-", his admiration for Millet, whose genius was inclined to those effects and to the difficulty that photography has in reproducing correctly strong effects of light and shade. Neither seem to me sufficient reasons for renouncing such beautiful and exhilarating phenomena of nature as sunshine and brightness of atmosphere. What can be more false " quality ? " This finishes my notes, and I trust that I have fairly described and judged the system advocated by Dr. Emerson and its results. As I said in the beginning he has done much to advance photography from an art point of view but has done much to spoil the effect of his teaching by the narrowness of his views and by allow- ing his natur,il artistic faculty to be interfered with by prejudice. He has sometimes also given pictures of his own to the public which were quite at variance with the theories he has taught andunworthy of his undoubted talent. G. Mansfield. INFLUENCE OF DEVELOPMENT ON GRADATION. Mb. Channox has done us the honour to make five experiments on the lines we have laid down, with the result of satisfying himself that the hundreds of experiments we have made go for nothing, and that our conclusions are erroneous. We cannot submit to be thus summarily disposed of, and as Mr. Channon's opinions may carry some weight, and so retard the progress of what we consider to be the truth, his recent article calls for soue reply. Mr. Channon's conclusions, summed up by himself in one sentence, are, "Development is likely to remain a mere rule-of -thumb matter.'" Nevertheless, he invites photographers to devote some part of their time to an attempt to add something to the small knowledge we possess of the action of developers. Assuming that we have done nothing whatever to throw even a gleam of light upon the action of developers, we think Mr. Channou might at least have credited us with showing photographers how to go about such an investigation, and with having worked out a system of experimental quantitative photography, of which he has not hesitated to avail himself, and of which he has so far approved as to draw sweeping deductions by its means. It is not encouraging to us to bo informed that things are, after all, only where they were before we devoted our attention to the subject ; and we warn those who accept Mr. Channon's invitation to make investiga- tions on development that, whatever may be the results they arrive at, they are sure to interfere with somebody's so-called experience, and to call down upon themselves the fulminations and the ridicule of such who cannot or will not adapt themselves to newer and brighter light. That the old views on the subject of development were not very deeply rooted, because not based upon sound experience, and were consequently easily shaken, is, we think, proved by the flutter and misgivings caused by our original paper. While Mr. Channon's opinion that " rule-of-thumh " development still holds sway may find acceptance on the jjart of that extraordinary body of photographers who revel in trying to correct " known errors of ex- posure," we venture to think that the majority of photographers would prefer to avoid " known errors of exposure," and to regard development as, on the whole, no very complicated matter ; indeed, as the compara- tively simple matter which our experiments have shown it to be, .and, as we shondence I replied "Kuowingthe vtilue of the system briefly, to the ett'eot that I should from more than twelve month.s' daily abide by my experiments, and such working, we are most desirous of -was the courage of my own opinions, offering the utmost facilities for its that I ofiered to submit everything to trial. Wo should be pleased if Mr. a disinterested jury, and I further Williams or any cmnmiUte of exparts offered to rejieat any individual ex- wovld take the matter up with us. periment such jiuy might select. To We invite Mr. Williams to favour us this challetif/e none of my dissentients with a visit at Southgate, and, in have responded." conjunction with our Mr. Cowan, practically test the tjieed numbers." Mr. Williams could scarcely expect us to respond to his challenge when he himself has not cared to accept ours, which was issued a week previous to his own. We still leave our challenge open for Mr. Williams' accept- ance, with any committee of experts nominated by the Society before whom Mr. Williams' paper was read. — We are, yours, *c., April 19, 1893. Mabion & Co. IJIPOKTAXT NOTICE— AMIDOL OR DIAMIDOPHENOL ; METOL OR MONOMETHYL-PARA-AMIDOPHENOL ; GLYCIN OE OXY- PHENYL-GLTCIN— PATENTS IN ALL COUNTRIES. To the Editob. Sir, — We beg to inform you, and we shall feel obliged if you will give publicity to the fact, that the patent disputes between the manufacturers of the above developers have been settled amicably by mutual consent, and hi future the sale of same in Great Britain and colonies will be effected through the undersigned firms, at even prices and terms. All photographic dealers will supply these products at the retail prices advertised, and professionals as well as amateurs will, no doubt, continue to derive satisfaction from the use of these now well-known developers. — We are, yours, &c., FiTEBST Brothkks, Henet Haussmann, 17, Philpot-lane, London, E.G., Dashwood Hotue, Xew Broad- Sole Agents for street. London, E.G., J. Hauff, Sole Agent for Chemisehe Fiibrik, Dr. M. Andresen, Feuerbach, near Stuttgart. ActiengeseUsehaft fuer A nilinfabrikation, Berlin. an£ftoer0 to Correspontients. "*,* All matters intended for the text portion of this JomtNAL, including queries and Exchanges, must he addressed to " The Editor, The British Journal of Photography," 2, York-street, CoveiU Garden, London. In- attention to this ensures delay. ,* Correspondents are informed that ice cannot undertake to anmser com- munications through the j>ost. ***i ^''!'"'"'^'<^''tions relating to Advertisements and general hisiness affairs should be addressel to Messrs. Hknry GBEEXWoob & Co., 2 York-street, Covmt Garden, London. PHOTOORArBS Registered :— Alexander GendaU tabaon. Penzance.— Tuio pholographt of t\e thip " HwM -flthore at St. MartiTi r, Scilly Islci.. Aleinnder Gendall Git-gon, Penmnce.— Turo phoiogrttpht <-/ the «Mp " Hor.a " athoreat SI. Martin't, ScUUj Islet. y 4 i j James Soamcs, Jan., Oiford.-Photojmph o/ a buVdoa dvemed in fiiotball cap ond jertey. Two photographi of bulldog, in iKimsl.r.' costumes. a. W. H.— In the formula referred to, cyanide of pota.?sium and tincture of lodme are meant. ' Rajar inquires if we can tell him of some good provincial town where the club system has not yet been introduced f — We cannot. X. Y. Z. — From your description, we cannot quite nndentand the alteration mode on the lens. Please send a rough drawing. IjIgiits. — Tlie address of the Incandescent Lights Company is Palmer-street, Westminster, S.W. W. J. N. — It is certainly possible to use sympathetic ink in printing, but water is usually the solvent for snch inks, whereas you will require an oleaginous ink. C. R. — llie question is one entirely for the County Court. As the man was acting as an agent, and not as a servant, we do not see how he can be charged with embezzlement AuoDST Baer (Winterthur). — We do not know the name of the manufacturer of the air brush, but Ross k Co. are the sole agents for this country. See advertisement in Almanac. Kd(;ar Scamkll.— Of the two designs for a studio we should prefer No. 1, if the ridge be carried more towards the centre and the glass also taken op proportionately higher. Avondale.— We have heard the London-made production well spoken of, but cannot speak of its capabilities from personal knowledge. We^think, how- ever, it should serve your purpose. E. Walker desires to know if grit would make his Beard's regulators unwork- able, and asks Mr. Birrell's ojiinion as to this, and further, as to whether the anti-friction arrangement could be adapted to them. Erratum.— We are reminded by Mr. W. Wray that, in giving their sources of supply of optical glass in our article last week, we have omitted the Jena glass, of which they use a considerable quantity. H. Dunning. — We have returned the correspondence to you. Possibly the matter had better end with the expression of our opinion that the matter was entirely one for settlement between you and the other party. W. W. T. — 1. We do not know any work which treats specially of photo- graphing anatomical subjects. 2. A paper on Architectural Photography, by Mr. S. F. Clarkson, published in our volume for 1886, may help you. Salop.— If you have publicly charged the man with infringing your copyright photograph, while you have no copyright in it, you wUl most likely find yourself in an unpleasant position. An apology ought to be tendered. B. W. C. — Ether should be used for thinning down collodion, especially so if the thickness arises from evaporation. We do not know the composition of any retouching varnish such as you describe, in which collodion plays a part. S. Singlf.ton. — No difficulty will Ije experienced in photographing in Germany, provided the camera is not used in the neighbourhood of fortifications. It will, however, be advisable to be provided with a passport in case of accidents. Inquirer.— We do not know any American paper that takes just such a posi- tion. Your course is first to determine in what city you would wisli to reside and then advertise in those papers published in that city. Having thus decided, you may write to us again. G. I. J. — The opening out of the aperture in the lens to f-9 should, theoreti- cally, cause it to work with an equal degree of rapidity to the rapid recti- linear of similar aperture, although of difi'erent focus, provided its correction is such as to give sharpness when thus opened. P. E. G. — We suspect that your cyanide ha.s lost its virtue by long keeping. Stick cyanide at best is but weak. As an alternative, try a strong mixture of solution of ferridcyanide of potassium and hyposulphite of soda, or you may use them singly, the ferridcyanide first, of course. S. Runniclhs (Braila). — The cement referred to may be obtained through any English stationer. Nothing is better for mountiug photographs than freshly made starch paste. Most, if not all, the cements sold that do not require heating are not to be reconmiendcd for photographic purposes. T. Jennings. — If the transparencies are not dense enough, they can be intensilicd. Carbon transparencies are intensified by treating them with a solution of permanganate of potash. The strength is uuirajiortant. Teu to fifteen grains to tlie ounce of water is, however, a good proportion. Dubious. — As you say that the toning and sensitising baths are in good onler, and that ouly three or four prints out of a batch are detective, it is clear the l)aper is not at fault. Therefore the trouble is due to the manipulation, but in what way it is impossible to say without seeing the operations carried out. Louis Meldon. — On examining the negative microscopically, we find a well- marked nucleus in the centre of each spot, but how cau.sed, or what it con- sists of, we are unable to say. Place a little of the water employed in a clean test-tube, and examine for any floating specks through a magnifyiag- glass. H. B. W. — If the negatives are very much under-exposed, there is no remedy in the development to anything like the extent there is with over-exposure. Amidol will sometimes bring out detail where pyro fails. Try that, and use a fair share of patience. Then some of the plates may be made to yield fair negatives. A. Rawson. — There is certainly no novelty in the idea of coating albumen prints with collodion with the oliject of making them more permanent. This was tried in a series of comparative experiments many years ago, and the result was that some prints treated with the collodion were found in some instances to fade quicker than corresponding ones that were not coated. From this it will be seen that the proposed patent, if obtained, would not be valid. 2oC THE BRITISH JOURNAL OF PHOTOGRAPHY. [April 21, 1893 W. O. J.^Head the articles on the various photo-mechanical processes in the AxMAKAC and then experiment for yourself. We fear you will not get much that is reliable with regard to the practical details of working without paying for it — and rather a good price, too. Practical details are treated much in the light of trade secrets. A. X. Y. — Very likely, if you exhibited, you might get a medal. We have seen worse pictures that have obtained medals at societies of the Little Peddlington type. These are the societies that the avowed " pot hunter" usually seeks. In the best societies he is usually conspicuous by his ab-sence. The prints would be best in platinotype. A. JIackixxox. — Your trouble is, no doubt, increased by over-sensitising the tissue. Five minutes' immersion in a five per cent, bichromate bath at this season is too much. Reduce the strength of the solution to three per cent, and the time of immersion to three minutes. Are you aware that carbon tissue can be purchased in small quantities ready sensitised ! .SULPHC. — 1. By procuring a copy of the Poisons Act from Eyre & Spottis woode, Xew Street-square, you would be able to see if the chemicals are scheduled. 2. We scarcely understand the question. Sulphite, as a pre- servative for pyro in solution, is best in a neutral state, although, as a rule, it is faintly alkaline. If it is placed with the soda solution, it is also doubt- less present with the pyro. W. C. Dru.mmoxd. — It will be very difticult to etch on glass by the method you adopt, because no portion of the surface is quite denuded of gelatine, which acts as a resist to the etching fluid, wliich we suppose to be fluoric acid. The interposition of a grating might aid you. Instead of glass, yo\i might try a copper or brass plate, and etcli in the manner adopted by Fox Talbot. DuBLix. — There are many causes that may conduce to an emulsion yielding foggy plates. If it were prepared strictly according to the formula quoted, we sliould say the most probable cause was over-cooking. lYy again, and boil for half the time, and see the result. The gelatine appears to be tlie right brand. But we may add that many of the finer kinds of thin gelatine are so simihir in appearance tliat it is quite impossible to recognise them by the examination of a single flake. A. J. BoxsoR writes as follows : "I have a quantity of chloride of silver from the wa>bings of jtrints. Is tliere -any means by which I can convert it into nitrate without sending it to the retiuer ? I may say tliat I have no furnace by which 1 could bring the chloride to the metallic state. I have heard or read somewhere that there is a metliod by which it can be done. " — Proceed as under : Wash the chloride, and drain it clo.sely. Then strongly acidify it with siUphuric acid and drop in a few pieces of Jiure zinc, and allow it to rest for a day or so. This treatment will n-duce tlie chloride to metallic silver. Any zinc remaining must be carefully removed, and the silver well washed. After the zinc is taken out, it is a"good plan to add some more sulphuric acid to dissolve any small fragments of zinc that may have become detached. After the silver is tlioroughly washed, it is dissolved in nitric acid and crystallised. ♦- Eeceived :— ilorley & Cooper's price list of cameras. Photographic Club.— April 28, Xoveltics in, JIand Cameras. May 3, Lenses/oi' Co^^ifinr/. The fishing picture, Strad)/, at tile Crystal Palace, wiiidi we referred to as being by Jlr. H. Young, should have been attributed to Mr. H. Sndth. Photographic Society of Great Bhitaix.— April 25, Technical Meeting, Tlie Manufacture of Gelatine Plates. A demonstration by Mr. J. Desire England at 8 p.m. Erilvta. — Mr. W. Birrell writes : " Permit me point out to vou that you have put ' cork ' instead of ' cock,' which renders the meaning of liiy last week's letter hard to discover." We have received from Mr. W. F. Slater, of 169, Southampton-street, S.E., his price-list of frames and mounts. .Mr. Slater's frames are always distin- guished by excellence of taste and other good iiualities. Messrs. Arthur Schwahz & Co. inform us that the specimens of coloured photographs sent in for the Bnmn's Gossy Colours Competition are on view at the National Photographic Exhibition now being held at the Crystal Palace. Messrs. Mariox & Co. inform us that thev aje bringing out a new trade catalogue in sections. They have sent us a copv of the section relating to camera stands and shutters, which is replete with illustrated descriptions thereof. Other sections will appear in due course. Redcctiox of Amidol Prixts ix the Fixixg Bath.— With reference to this, Mr. A. K. Dresser has handeil us our bromide prints, developed each respectively in sulpho-quinone, metol. eikonogen, ami amidol. The develop- ment was in each case carried to tlie same stage, and tlie prints were soaked in a strong solution of liyposulphite of soda for a night There is no apparent reduction in any of them. It is Mr. Dresser's opinion tliat tlie reduction of amidol-developed images would not be heard of if photographers would give a shorter exposure and a longer development. Cry.stal Palace Natioxai Photoobaphic Exhibitiox.— List of awards. Xational challenge cup, the West London Photoeraphic Society : Gold medal VV. M. Wameuke ; silver medal, E. T. P. Goodwin ; bronze medal, Messrs.' Morgan k Kidd, A. R. Dresser. Art division : Silver medals, William Howell, C. H. Oakdec, W. .J. Wright, J. E. Goold, C. Job, E. Hawkins, (i. Hankins Miss A. Heath ; bronze nied.nls, F. W. Edwards. G. H, Catt, R. H. Lord • certificiites, Douglas Pym, E. M. Stone, C. Court Cole. Scientific photographs ' SUver medal, Sir Henry E. Roscoe and .loseph Lunt (joint exhibit) ; bronze medal, John Carpenter. Lantern-slide division (professional photographers)- Silver medal, George E. Thomson; bronze medal, P. H. Fiucham. Amateur photographers : Silver medal, F. Golby ; bronze medal, J. Shaw, G. Bingley ; certificate, Harry Holt ; silver medai, W. E. Cowan ; lironze medal, J. O. Grant ; certificate, W. Taverner : bronze medal, W. C. Beetham ; silver medal, F. Auyon ; bronze medal, E. Dockree. Destrpctive Fire at a Babxsley Photographer's.— a fire which caused considerable damage occurred on Wednesday night, April 12, on premises in Sheffield-road, owned by Mr. Walter Guest, tobacconist, and occupied by Eastman's, Limited, butchers ; Mr. Eddison, photographer ; the Danish Butter Company ; the London and Counties' Tea Company ; and others. The fire was discovered by Inspector Mellor and P.S. Williams about nine o'clock on the night named. They at once gave information to the Corporation Fire Brigade, who were soon on the spot. They were able to obtain a good supply of water from the street mains, and the fire was totally extinguished by eleven o'clock. The greatest amount of damage was done to the property of Mr. Eddison. The room which he occupied was used as artists' room, and con- tained a number of pictures that were ready for sending out, and also frame mouldings. Mr. Eddison estimates the damage at about 1000?. His nroperty was fully insured witli the Royal Exchange Assurance Company. Tlie* damage to the building is computed at 350/., and is also covered' by insurance. Messrs. Eastman's damage .amounts to about 50Z. ; and the Tea Company's to from 50/. to 100/. It appears from subsequent examination that the fire began in a small place partitioned ofl' from the butcher's shop, to which it belongs. Boltox Photographic Society's Exhibitiox. —On Wednesday, April 12, the Bolton Photographic Society openedan e.xhibition of itswork. Mr. J. R. Bridsou J.P., the Presidentof the Society, had for exhibition over a dozen fine pictures, including portraits of Princess May, Miss Bridsou, Miss Fortescue, and various landscapes, some of which were workeil up iu colour and crayon. In portraitxire therewasaveryfairrepresentationof professional artists hi the town, some highly iinishedworkbeingexhibitedljy Mr. Xatlian S. Kay, Mr. F. Proctor, and Messrs. Weatherley, Bros, whilst Mr. H. Birtwistle was also an e.xhibitor in this clas.s. Mr. J. S. Roscoe, a skilled amateur, had several landscapes on view, and also worthy of special mention in the miscellaneous exhibits were Messrs. Walter Staton, W. Collier, W. L. Entwistle, H. Haywood, J. Kellett, W. Green, and A. Harper. Other exhibitors who figured very creditably were Dr. Johnston, and Messrs. E. J. Roscow. F. Roscow, J. Thomley, Jabez Boothroyd, R. Fielding, jun., R. Paiton, S. L. Coultluirst, A. Graham, J. Leach, Jas. Morris, J. H. Galloway, R. Leigh, R. Gregson (Blackburn), J. H. Cowan, J. Lomax, 1. Brooks, and J. Young. Several manufacturers of photographic materials had on view specimens of tlieir latest processes, and local dealers iu jdiotographic outfits, including Mr. W. Banks, Corporation-street, and Mr. T. H. Heyes, Deansgate, had very interesting exhibits of their speciiilities on view, 'fhe Eastman Company had on exhibition eight views as specimens of their bromide and solio processes : but the exhibit which was the commanding attraction in the room was .Messrs. Elliott & Son's green carbon enlargement, Jireak, Weak, break, at the foot o.f thii crags, 0 sea.' which is seven feet by five feet in size, and attracted great attention at the Pall Mall Exhibition last year. In ojiening the Exhibition Mr. Bridsou expressed his pleasure at seeing so large an assembly and such an encouniging manifestation of interest by the puldic in the science of photography. He thought the display on view that night was a gi'eat improvement on its predecessors. The Bolton Society had V>eeu in existence fourteen or fifteen years, and had a niembe.r.ship of one humlred, which he trusted might be iiicnascd as the result of the Exhibition. The results of the judging were then announced as follows : — Members of the Society only : Class 1 : Best set of six jihotogiMphs from negatives taken since March, ISSO. — ], Silver medal, W.-dter Staton ; 2, bronze medal, H. Heywood ; 3, bronze medal, A. Harper ; and liighly commended. Dr. Jolinston. Class 2 : Best set of at least six photographs taken at Society's outdoor meetings during 1S92. — 1, Silver medal, W. Collier ; 2, bronze medal, W. L. Entwistle. Class 3 : Best set of transparencies from negatives taken during 1S92. — 1, Silver medal, W. L. Entwistle ; 2, James Kellett ; 3. Ernest J. Roscow. Class 4 (open to all professional photographers) : Best set of six portraits. — 1, Silver medal, N. S. Kay : 2, bronze medal, F. Proctor. Classes 5 and 6, no competition. Class 7 : Best picture in the Exhibition, belonging to any mem- ber of the Society. — 1, Silver medal, J. S. Roscow ; 2, bronze medal, W." Green. As supplementary attractions to the Exhibition the Committee arranged a series of musical entertaiuments and an excellent programme of American and otlier scenery. The Judges were Messrs. J. H. Welch, E. L. Marriott, and H. Hall, of the Liverpool Amateur Pliotographic Association. The Exhibition closed on Saturday. The room was crowded, the chief attraction being a lantern display, the I'caks and Dales of Derbyshire, which was highly ajipreciated. During the four days the Exhibition has been open ujnvards of 1200 people have visited it, and it has been a thorouah success in every way. *»* We have receiveil from Mr. Joseph George Hudson the sum of 15.5., the. proceeds of sale of groups taken by him at Anclcrton's Hotel on February 11,) 18512, and which, as requesteil, we have handed over to the Treasurer of thS Photographers' Benevolent Association. CONTENTS, Paob THE CAMERA CLfE CONFEREXCE- VAX DEI: WEYIIES PHOTOCOIl- HKCT0R •• 241 LESS SCREEXS 213 HESTORIXQ FOGGY PLATES. By W. B. UilLTOX 341 JOITINOS. By COSMOS 215 UETOCCHIXO. By WILLIAM PARRY.. 240 Sli.ME XOTES OX XATUEALISTIC I, PHOTOGRAPHY-. By O. JIAXSFIELU 217 IXFLIEXCE OF DEVELOPMENT ON GUADATIOX. By V. HURTER akb V. C. naiFHELIi 218 Vxam CAMERA CLUB CONFEREXCE IM THE SAXDELL EXHIBITIOX CEXTRAL PHOTOGRAPHIC CLUB 251 OUR EDITORIAL TABLE 251 RECENT PATENTS M» MEETINGS OF SOCIETIES FORTHCOMING EXHIBITIONS 881 CORRESPONDENCE IB* ANSWERS TO C0BBESP0XDENI8 » THE BRITISH JOURNAL OF PHOTOGRAPHY. No. 1721. Vol. XL.— APRIL 28, 1893. PERSPECTIVE IN PORTRAITURE. SoMEWUAT allied to, and suggested by, the subject of our article laat week on the so-called photo-corrector, is the cognate subject of incorrectness of portraiture, produced by placing the lens and camera too near to the sitter. Every one knows that, if the hand or foot projects, it will be rendered on a scale larger than it ought to be in comparison with the rest of the figure ; but every one does not, seemingly, realise that this applies also to the projecting parts of the face ju relation to those further away from the lens. This perspec- tive distortion is, in both cases, the more pronounced the closer the lens — the point of sight — is to the figure. By receding, or withdrawing the camera to a greater distance, this disproportion becomes less and less, until it ceases to be noticeable. While no one with any artistic perception would pose a figure so as to allow the hands or feet to unduly project, still t may be well to indicate in what manner such may be equalised without the necessity for having recourse to ad- ventitious modes, such as are afforded by retouching or " photo- •correctors." The simplest and most obvious means for adoption is to avoid placing the camera too near the sitter. If, as we have seen some do, the lens is brought to within six or eight feet of the sitter, or even still closer, as when a large head is desired, what can one expect other than this distortion of perspective ? "While it is true that the perspective is not really false, still it is violent, and the portrait obtained in this way may not convey an accurate idea of the sitter. A useful object-lesson is to make a direct large portrait of a sitter from a distance of four to five feet, and then remove the camera till twenty-five or thirty feet intervene between them, afterwards enlarging the portrait last taken until of the same size as the first, and then comparing the two. It wiU be seen how much superior the one is to the other. Some studios may not be sufiBciently long to permit of this being done ; and this is a great misfortune, for, while no studio should be under twenty feet in length, it is still better wheu it exceeds this by twelve feet, or is thirty- two feet long. If it is found that at a distance of about fifteen feet the portrait is too small for the dimensions required, it is much preferable to attain this end by employing a lens of longer focus than moving the camera much closer to the sitter. What is said here about diminishing the too violent perspective of the component parts, so to speak, of a single sitter, applies also with even greater force to the taking of two or more figures in one picture. In the case of a sitting figure, in which the feet almost necessarily project, any apparent enlarging of them can be reduced by the judicious use of the rising front and swing- back of the camera, observing this, that, in order to reduce the size of the feet, that part of the focussing screen — the top — on which these members are depicted must be brought nearer to the lens, although, when the face has been brought to a sharp focus, the feet, especially if the lens is at full aperture, will be less .sharply defined than if the tilting were in the opposite direction. This defective definition must be ameliorated by stopping the down lens. The adoption of the system here outlined will prove useful, if not quite necessary, to the photo- grapher whose studio is limited in length. Who that is interested in the perspective distortion of the human face does not remember almost with a shudder the "chamber of horrors " opened iu our midst in 1872, on the occasion of the late Mr. Robert Crawshay, of Cyfarthfa Castle, Wales, having offered liberal prizes for the prooiling the tilni. I constnict one or tiotli vjuU of the roller to form n >dut<:h to engage with the fittings of tlie camera or roU-hoUliT, tlureby enabling the roller to be torned from the outside of the (.-.ISO liy the winding key. In iinlir to euiiblc my innirovod light-tight ilm packages to bo used in roll- holders or cameras as usually eonstructed, which are not adapted for being rhorged or refilled in daylight, and in which the fittings of the nischarging and receiving rollers are not of a uniform pattern, I provide a device which I term an " adajiter." This device is adapted to fit without tuniing in the end of my iiuprovol spool or roller, and is shaped :it its outer end to fit on the Msnal key or clntch of the receiving roller of the ordinary roll-hoMcr or camera. This "adapter " can be arranged to fit or connect with any kind of clutch, and is removable or interchangeable. By means of this device my film packages can lie u.sed in existing cameras and the empty spool or roller with its light-tight ca.se may be u.sed as a receiving roller, the ordinary receiving roller fteing dis- l>en.sed with. When the receiving roller is full, it can be removed and an empty .spool with its light-tight case put in its place, the "adapter" being changed from the full roller to the empty one. The claims are :— 1. A film package or c.ise having a roller provided with an :innular groove in one or both ends, to form a bearing surface or liearing sur- faces on which the roller can turn for the purpose specified. 2. A. film package or case provided with caps or end pieces having annular interval projections to form bearings for the roller, substantially as described, for the purpose speci- fied. 3. In a film package or case, a roller having an annular groove formed in one or both ends, fonning bearing surfaces for the roller, in combination with end pieces having central openings, the ed^es of which are turned inward and are adapted to fit in the said annular grooves for the purpose specified. 4. The combination with the light-tight sheaf or covering and the roller, of thin sheet metal or other suitable end jiieces, having rims adajited to fit tightly on the shcatli and central circular ojienings, the edges of which turn inward and are adapted to enter annular grooves in the ends of the roller, and form iiearings for the roller, with or without other fa.stenings to hold the ends in place, substantially as described for the purpose specified. 5. A light-tight film package or case prorided witli internal annular bearings for the roller, which enable the roller to be rotated from outside the case, substantially as described. 6. A light-tight film package or case constructed substantially as atc ol Meeting. Jlajl '* 1 .. 1 1 " 1 " l.„ ** 2. 8 " 8 2 2 * 2 ' 2 2 .. .2 2 " 2 * 2 h 2. 3 . 8 3 3 3... . 3 • 4 4 4 •• 4 4 4 4 4 4 4 tV' 5 5 M 5 5 5 6 Name of Society. Camera Clnb Bundee Amatoor Petorborough ,.„... Putney „ Richmond South London Stereoscopic Club Birmlnf^ham Photo. Society , Bolton Photo. Society Brixton aud Clapham Exeter ;., Haclniey Herefordshire Lewes North London Oxford Photo. Society Paisley Rotherham SheiBeld Plioto. Society York Edinburith Photo. Society .... Leytonstone Pboto^rraphic Club Southport South&ea Wallasey Birmingham Photo. Society . Camera Club Dnndee and East of Scotland . Glasgow Photo. Association.... Olosaop Dale Hull Leeds Photo. Society London and Provincial Oldham Tnnbridgo Weils .' Cardiff , Croydon Microsoopical Holborn Leamlnirton ], Maidstone Hnll ■■■ Place of Meetin([. Charing- Cross-road, W.C. Asso. Studio, Nethergate, Dundee. Museum, Minster Precincts. Hfgh-street, Putney. Greyhound Hotel, Richmond, Hanover Hall, Hanover-park, S.E. Brooklands Hotel, Brooklands. Club Room, Colonnade Hotel. 10, Rushton-street, Bolton. 376, Coldharbour-lane, Brixton. City Chambers, Gaudy-st., Exeter. 206, Mare-street, Hackney. Mansion House, Hereford. Fitzroy Library, High-st.,- Lewes. Canonbury Tower, lalin^rton, N. Society's Rooms, ISfi, High-street. 9, Ganze-street, Paisley. 5, Frederick-street, Rotherham. Masouic Hall, Surrey-street. Victoria Hall, Goodramgate, York. 38, Castle-street, Edinburgh. The Assembly Rooms, High-road. Anderton's Hotel. Fleet-street.K.C. The Stuilio, 15, Cambridge-arcade. 3, Kimr'j^-road, Southsea. Egi'emont Institute, Egremont. Clnl) Room, Colonnade Hotel. Charing Cross-road, W.C. Lamb's Hotel, Dundee. Philuso. Boc. Rooms, 207, Bath-st. 71, Prospect-street, Hull. Mechanics' Institute, Leeds. Champion Hotel, 15, Aldersirate*Bt. The Lyceum, Union-street, Oldham. Mechanics' Inst., Tnubridga Wells. Public Hall,George-Btreet,Croydon. Trinity Church Room, Morton-st. "The Palace," Itaidstone. 71, Prospect-street, Hull. PHOTOGRAPHIC SOCIETY OF GREAT BRITAIN. '^'^"' ^■—Technical Meeting,— Mr. T. Sebastian Davis in the chair. - ■ vl* • ^*<"*t'"'y exhibited and explained a model of a new hand camera :>y Messrs. Campion * Delacre. It has a refiecting mirror inside, so that the lawge can be seen of the size of the original. The principal movements are elTected by working a lever at the side of the camera, which first of all uncorem the lens, then covers it np, actuates the ahntter, and changes the plate. It was said to be possible to expose a dozen plates in twenty-live Mconds in thki camera. "Tht Masl-facttrr ok Okijitijib Dry Pl.*tw." Mr. J. Bismi^: Bnhland gave a practical demonstration of gelatine emnlsion- making, saying that if no great rapidity was desired, the first process he should ilcscrilw was a very simple one for the purpose. Sensitiveness depended upon the formula and methoiassed, ho might have suggested that the apparattis was wrong, or that some matter had upset the results which would not destroy the theory. He had said elsewhere tliat he did not care to accept Uis (Mr. Cadett's) challenge, knowing that the theories of both of them were so wide apart, but- Mr. Williams had never given his view of the theory. Mr. 266 THE BRITISH JOURNAL OF PHOTOGRAPHY. [April 28, 1893 Williams said he did not believe the statement with regard to the densities, or rather of the opacities, being proportional to the exposure, therefore the theory was wrong. The whole theory of the system was that the opacities were directly proportional to the intensities of the light that produced them. That was either right or wrong, and if Mr. Williams said it was wrong, perhaps he would tell them why. Mr. Williams had pointed out the admission of an error on their part. It was true that in December he and Mr. Cowan had admitted errors of twenty-five per cent, with the standard candle, but that was stated in Dry Plates before Mr. Williams's paper appeared. As regards what Mr. Driflield had said as to orthochromatic plates, he wished to qualify what he had told them. He had made no systematic or exhaustive investiga- tions on the subject. In the few instances of orthochromatic plates tested, he had found the speed ascertained by candle to be confirmed in the camera. Having complained of Mr. Williams's tone with reference to orthochromatic plates, Mr. Cadett said he had not conveyed that orthochromatic plates were not orthochromatic. They clearly were so. Last week at the Camera Club Conference, he had attended Captain Abney's and Mr. H. M. Elder's lectures on the speed of plates, and he was exceedingly pleased to find that they both confirmed the general accuracy of the Hurter & Driffield system. Captain Abney was a strong opponent of the system, but it was a pleasure to argue with him. He (Mr. Cadett) could confirm what Mr. Cowan jiad said as to the system being right. Mr. Williams said the system would probably be thrown up. Mr. Williams was wrong. They wanted figures before them before they gave it up. At the previous discussion Mr. A. C. Edwards remarked of the two plates passed round by Mr. Williams, one of which was developed more than the other, that any one could see that one had had a little more exposure than the other, and asked wliy Mr. Williams should have forced it. Even among two opponents of the Hurter & Driffield system, they found very con- siderable divergence. With regard to the Warnerke system, there were two reasons why it was not successful ; one was the practical dilficulties of making the screen, and the next was that all those who used it found that if they judged the exposure by the last few faint tints, it did not agree with the camera tests. In Mr. Williams's tests he went for the last faiut tints and those only. In using the screen we got into that very period of under-exposure which Hurter & Driffield pointed out. We used to get into the habit of in- cluding the last five figures, and try and judge by the row immediately pre- ceding them. Messrs. Hurter & Driflield said that, theoretically, the point chosen by them to indicate the speed of the plate was not the correct one ; it was a sort of geometrical mean in the densities, but practically it would not be easily found, so that they carried tlie line to the base, and made a constant. Those who found fault with the figures in the Warnerke system were trying to get at what Hurter k Driffield had got at. In testing plates to-day, they only found a very small period of correct exposure, all the rest was either over or under-exposure. The result was, that unless we took a range throughout the speed, it was quite impossible to tell what the correct speed was. During the last two days he had tried some foreign orthochromatic plates with regard to the Hurter & Driffield system. He found that the period of under-exposure was so enormous, that he practically got two straight lines in the two cases. Mr. W. K Debenham said that, with regard to the question of orthochro- matic plates, the use of a candle was really equivalent to that of a screen ; the light contained some blue, but it was very rich in yellow. If a plate was found which bore the same proportion to candle-light and daylight, it should not be called orthochromatic. Those who have affirmed that they find no difference, should make some conclusive tests, and show them to be similar. His impression was they would come out as from 4 to 10 : 1. Mr. Cadbtt did not find that the orthochromatic plates he had tried were very slow in the camera. Mr. Cowan had cut two standardised plates in half, and taken two medium and two instantaneous isochromatic plates. One of each three was exposed to candle-light without any screen. Upon measuring, the ordinary plate came out 1-15, the medium isochromatic I'l, the instantaneous -55, j>ractically double the speed of the medium. Then he had exposed the other three, using the yellow cap and the readings were respectively, '80, -775, -475, so that the three plates practically kept then- same relative rapidity with the glass that they did with the candle. Mr. Cadett had witnessed measurements of orthochromatic plates by the spectrum, when it was found that their sensitiveness to yellow had increased 500 times. Mr. Debexham understood Mr. Cadett to say that he found the camera not accurate. If by comparison with Hurter & Driftield's tests it was not accurate then that system nmst be wrong. Mr. Cadett had sjjoken of the Warnerke sensitometer giving incorrect results if we took the last few figures. On that point Mr. W. K. Burton and he made some experiments several years ago, proving that if the last few numbers on the Warnerke screen came very much alike they ought to be disregarded, and that they ought to take the point where there appeared to be a decided increase. Messrs. Hurter & Driflield had done a very good thing in carrying that idea out, and showing where the point of departure should come. As regards Mr. Cadett's question to Mr Williams as to whether he wrote for Photographic Scraps as " Technique " he would ask Mr. Williams in consideration of journalistic etiquette not to give any reply to the question. After some remarks from Mr. J. B. Spurge, who said he got the same shape of curve with any system, and who promised to develop the subject of his remarks on a future occasion, ^.r^,""' ■'^^•"'^'' Cowan read the following remarks on the subject :— In Mr Williams s original paper he mentions that, "when the unreliability of Warnerke s sensitometer became apjiarent, our plate-makers quickly relin- quished the issue of plates bearing any actinometer or sensitometer number and a pretty general return set in to using the old nomenclature, such as ordinary, medium, instantaneous, drop-shutters," &c. And Mr. Williams further remarks that the description given to their plates by makers of good brands is such as probably fulfils all present requirements ; the name fiirly indicates the speed, and in the absence of any reliable method is actually preferable to misleading numbers. Now, I think that Mr. Williams if he always made his exposures according to these names only, would find himself more at sea than if he went by these numbers ; for to suppose that plates issued as ordinary or special, or whatever title it may be, by different makers, should of necessity be of the same speed, is out of the question, and, as has been the case this last year, where plates of even the same brands have been probably nearly doubled in speed. It is rather surprising that Mr. Williams (who in the commencement of his original paper) regrets that in photography we have no apparatus for the nicety of measurements such as we have in kindred sciences, should be content to judge his results in an unscientific manner when he can have at his command a system based on scientific principles, and which has taken years of patient thought and experimenting to build up and give as it was freely to the world for the advancement of the science of photography. The fact that the conclusions arrived at by Messrs. Hurter & Driffield are at variance with the ideas of Mr. Williams and other photographers does not of ne- cessity in any way invalidate their system, any more than the old idea that the earth was flat did not in the least alter the fact that it was round all the time. And I hope in the same way we shall h.ive Mr. Williams, when he has gone more carefully into Messrs. Hurter & Driffield's system, and worked it out for him- self with the proper instruments, that he will find there is more in the prin- ciple than he at present thinks. Mr. Williams, I suppose, will admit that for every plate exposed, on whatever subject, there must be within the limits of the plate and the subject some correct exposure, and I should think he would admit that the more data that can be given to enable the operator to correctly judge that exposure the more nearly will his result approach perfection. Mr. Williams took objection to Messrs. Hurter & Driffield's photometer, and said that he found that he could not read the same with precision within two or three degrees. Claiming perhaps to have made as many readings with this in- strument as any one, I must emphatically .say that, if readings cannot be made within five per cent, of error, it is the fault of the operator, and not the instrument ; only, of course, it cannot be expected tliat the first time any one reads with an instrument of this sort that they can at once master all the technical difficulties that have to be contended with, any more than if we set a novice to weighing in a chemical balance, anil expect him to do it off correctly at once. Mr. Williams will, I should think, admit that when a new system is brought out, and a system which re- quires a certain amount of experience to work, it is not to be expected that, at the first go off everything is to be perfect. It must of necessity be a work of time to find out and rectify any little difficulties that may be met with, and, if any errors have occurred at the outset, they are surely not sufficient evidence to bring forward against the system itself. Mr. Wilson mentioned that he thought Messrs. H. & D.'s system was correct, within certain limits, but that development and temperature might affect the result. It was for this very reason we recognised the necessity that all who used this system should work with a developer of fixed proportions for a fixed time and at a fixed temperature, and we hope to be .ible in time to give a nu- merical value corresponding to alterations in development and temperature. But it must be understood that those who use this system and wish to work to the same standard of speed should carry out all their tests under precisely the same conditions. Dr. Hurter at the Camera Club very ably expressed in the form of an equation the different factors which governed the negative or as he expressed it, R the result. R=I, L, T (S) D, t', (p. He shows that R, the result, is governed by the following factors : — First, the I or intensity of the light ; T, time of action of that light ; L, lens which reduced it on to the plate. These for simplicity we may call (k) or exposure. Then we have the speed of the plate (s) :— (D), development ; (<'), time of development ; k, temperature of development. . ■ . We have an equation, R = E, (S), D, «, 0 ; So that here we see Messrs. Hurter k Driffield do admit there is control of the negative. From this equation we know that, keeping all conditions the same, our result, R, must be the same. And therefore, to get always the same value for S, the speed of the plate, we must keep the remaining factors constant. Then, when we know the speed of the plate, we can find what alterations we can get in R, our result, when we vary either E, D, t, or 0. So that here we have a very valuable stepping- stone to enable us to estimate the value by different alterations in develop, ment, temperature, etc., what we certainly did not have, before Messrs. Hurter & Driffield gave their valuable discovery to the world. Mr. P. Evekitt said that the difference of results which Mr. Williams had noticed when compared with Messrs. Cadett and Cowan's might be largely due to the manner of procedure. Mr. Williams, perhaps, had not been accustomed to using Messrs. Hurter k Driffield's instruments, of which Messrs. Cadett and Cowan had had extensive experience. Mr. Williams was in the position of a man with a delicate chemical balance, who was used to weighing with a chandler's-shop scales. A person who judged densities as Mr. Williams had done was in that position. [Laughter.] They must also bear in mind that, if the Hurter & Driflield system was based on the standard candle, it liad a variable balance to work on. It did not militate against the system if the results varied. The difference lay in the instruments used rather than in the system. Mr. Debenham remarked that if Mr. Everitt had been aware that Mr. Williams was one of the earliest experinientei-s with rapid plates, he would have withdrawn that observ.ation. Mr. Everitt did not mean to make the observation with any personal intent. Mr. Williams, in reply, said he felt he must not touch upon aU the subjects raised, or they would not get away that night. As to Mr. Cowan's remarks April s. 896 THE BRITISH JOUENAX, OF PHOTOtiRAPHY. 287 on the jury, what he (Mr. Williams) had said had been misunderstood. His (Mr. Williams's) proposal was that the jury might be selected by those gentle- men who wore in opposition to liim, and for them to nominate it He was prepareer was not then ao deeply coloured by it as at first, showing that the hypo in the prints had attacked the iodide in the solu- tion, and rendered it less jiowerful to produce iopecially fine were a series of interiors of Glon cester Cathedral, beautifully chosen, and splendidly executed. A number o hand-camera .seaside studies were also very good. Derby Photographic Society.— April 18, Mr. A. B. Hamilton occupyin the chair. — The Chairman .announced that two delegates were required for the Photographic Society of Great Britain in connexion with the affiliation scheme. Messrs. R. Keene and T. A. Scotton (Hon. Secretary) were elected. Mr. E. Keene was then called upon to give a paper entitled A Six Days' Photographic Tour through iJerbyshire. This tour took place between twenty and thirty years ago, when photography was very much dift'erent from what it is at the present day, the party having to take with them a huge cart, with rope attachment, and which they had great difficulty in pulling about from i>lace to place. Commencing .at Row.sley, where the Midl.and Railway then termi- nated, the route taken was by Baslow, Eyani, H,athersage, Castleton, Miller's Dale, and back to the starting-place. Mr. Keene had to illustrate his paper by 170 lantern .slides, most of which had been taken on this excursion. 'I'hese were very beautiful examples of his work. Mr. C. B. Keene officiated at the lantern. Gosport Photographic Society.— April 11, Mr. T. E. Williams, Vice- President, occupied the chair. Mr. R. E. Froude read a paper on Sxperkuces of a Kodak with Cii/Uinuoi's Films. Newark Camera Club (Newark, N.J.).— April 10.— The following Oflicer.s were elected for the ensuing year: — President: Mr. Thomas A. Hine.— ^;■■>•- /'re.sirf(■wi.■ Mr. J. M. Fooie.— li.eecutive Committee : Messrs. William Archil M Harry W. Smith. WdlhamA. Uahsey, Charles Laroy, Frank S. Olds, A. C. Jliii' H. C. ilcDougall, J. M. Foote, Fred A. Sa\i\u:U.— Treasurer : Mr. C. G. U:. — Secretary : Mr. D. S. Plumb. AprU 28, 1898] THE BRITISH JOURNAL OF PHOTOGRAPHY. Newcastle-on-Tyne Photographic ABSoclatlon.— A monthly meeting of tho Ncwcustle-oiiTviio ami Nortlieni Counties rhoto);rai>hio Association was hfhl on April 11 in'tlie Min'ting-rooni of the Art Gallery, Newcastle. Mr. II. 0. Uiilgeway ( Vioe-Presiilent) was in the chair, anil there was a large attendance of members. — The outdoor meetings for the present year were ti.Ked as follows : — Hay, Stawanl-le-Pcel : June, Fountains Abbey ; July, Kichmond ; August, Alnwick ; September, Soaton Sluice and Seaton Delaval. Mr. William Pabbv reail a iiajier on jietoitchin;/, and a discussion followed. Rotherham Photogrraphlc Boolety.— April 11, Dr. Baldwin (President) in tlie chair.— Thr«e new members were elected. Mr. Leadbeator (Treasurer), in n pajwr on hand cameras, considered such apparatus as the premier plate spoiler, .and said he should lilie information as to the proportion of really good negatives out of total plates exposed. When understood, the hand camera was a most interesting ami enjoyable companion, and had been one of the best advertisers of modern jjhotography. Hints on construction and use of hand cameras, and also on plate and lilm development, were given. Society of Amatenr Photographers of New York.— April 11.— The following Ollii'.crs and Directors were elected for the ensuing year. President : Mr. K. A. B. Dayton. — Vice-PrcsUUnt : Mr. L. B. Schram. — Directors; Messrs. C. Van Brunt, K. L. Bracklow, R. H. Lawrence, F. C. Elger, K. Warrin, H. S. Mack, H. A. Smith, A. P. Schoen. — Treasurer: Mr. C. C. Uinimage.— Rccuci/i.'/ifl' Secretary .Mr. T. J. Burton. —Co rrospo/uiinj Secretary : Mr. W. F. UxpgooA.— Secretary : Mr. T. J. Burton. FORTHCOMING EXHIBITIONS. April 28 29 "Crystal Palace. The Executive, Crystal Palace, S.E. 2S-29 "Photographic Society of Philadelphia. Hon. Secretary, R. S. Rediield, 1601, Callowhai-street, Philadelphia, U.S.A. May 4-6 . ... "Forfarshire Photographic Association. Hon. Secretary, W. J. Anckorn, West Port, Arbroath, N.B. * Signifies that there are open classes. « iE.TCtjangc Otolumn- *»* No charge is viade Jor inseding Exchanges of Ai}paratns in this column; but none icill he inserted unless the article wanted is defimtehj stated. Those tciw specify their requirements as 'Uuiythdng useful" loill therejore understand tiie reason of their non-appearance. The full navie of the advertiser must in all cases be given for publication^ otherwise iJie Exchanges will not he inserted. • Excluinire Morif au's multiplex baoki^Tonnd fur stadio accessorios, cliiltlren's principally. — Addru.^s, Paekisson, photograpliur, Warrington. KM'lian;:!; cabinet roUiuf; macluno. j>liito tjla&a bed, for trood cabinet lens, background, or studio came i-a.— Address, C. H. Hatch, Alderley Edge. Wanted, balf-plate camera, McKollen or similar pattern, in exchange for Marion's emljossinff press complete.— Addi-ess, W. H. Humt, 73, Trafalj^-road, Peck- ham, B.E. Wanted, 12 x 10 camera lens, modern make ^lobe enameller, stereoscopic ontfit or hand camera. Excbaniro tricycle by Singer &, Co., Coventry, almost new. — Address, J. ^BTOV Brioos, ^Vliitby. Exchange tricyle, Boeston Hnmber, worth 51. or 61., for 10x8, 12x10, or hand camei-u; machine in good condition, and eaey driver. — Addreas, B. H. Bltth, pUotograpUor, Ilfracombe. Wanted, good wholo-plate field camera, reversible back, with three or six slides, case and stand, in exchange for 10x8 camera (Fallowfiolds) and two slides. DifCerence cash.— Address, Whitk, High-street, Lejvisham. Will exchange quarter-plate camera, Ktnuear pattern, latest improvement, three doable slides, three foldinir tripod, for half-plate camera, Kiunear pattern, and three double slides, and tripod iu good condition, approval.— Address, J. E. Suitii, Little London, Rawdon, near Leeds, Yorks, Corre^poniyence. Corrtjspondeuts should never write on both sides oj the paptr. ^o notice is tcJun of communications unless the names and addresses of tliv tenters are given. MB. TEAPE AND THE SANDELL PLATES. To the Editob. Sin, — Keterring to Mr. Teape's letter in your last issue, I am glad to note that he continues to find the "Sandell" plates less subject to halation than the other plate against which he tested it. We are at one upon that head, and when my critic consents to abandon the pseudo- scientitic or magnesium - wire method of testing, and instead makes negatives upon the plates, for which purpose they are intended, I think we shall be in accord again in tho finding that for all practical purposes a multiple film gets rid of the defect of halation. There is no test so con- vincing, and 1 may add so useful, as the test of making a negative upon the plate under trial. There is none so liable to mislead as the semi- scientific test. But, whatever test be adopted, development should be effected so as to make the best of each competing plate. Begarding the " tentative " development, I am quite doubtful whether Mr. Teape and I mean the same thing. Sixty-five minutes, as mentioned in his letter, ig slow development, not tentative. By tentative dovclup- ment I mean tliat I begin with a sufficiently weak and rcstrainod solution, which I gradually increase in energy by adding a concentrated developer, and I take care to only make the solution sulllciently energetic to produce an image of proper density. This will never take more than ouc-thixd the time quoted by Mr. Teape, and seldom so long. I do not think I need trespass further upon your space. Kr. Teape concedes all I ask, viz., that the multiple film gives less halation than a single film. It is therefore a step in the direction of progress. — I am, yours, &c., S. Hekuekt Fry. April 24, 1893. To the Editob. Bib, — In reference to Mr. Teape's letter in your last issue, you will perhaps allow me to make an observation or two. I have not the pleasure of Mr. Teape's acquaintance, therefore do not know what measure of accuracy to expect from him ; but I must beg of him, in again quoting or experimenting with " Sandell " or any other make of plates, to be some- what more specific in his description. He should have known, I think, that " Sandell " does not sufficiently describe tbe plate when spoken of in connexion with halation experiments. Would he think me honest if, in writing or speaking of Messrs. Wratten's plates at a Society meeting, I asserted they were not rapid on the strength of exposures made on their " ordinary " plate ? There is far too much of this culpable carelessness cuirent, sir. The offenders forget their words appear in print and are liable to befool a greater circle than their immediate listeners. — I am, yours, &o., J. T. Sasdeli.. Thornton Heath, April 24, 1893. [We can so readily testify to Mr. Teape's care and fairness as an experimentalist that we are sure he would be the last to willingly convey a conscious inaccuracy. The correspondence here terminates. — Ed.] ABT IN PHOTOGEAPHY. To the Editor. Bm, — Last week's edition of this Joubmal, contains, under the heading " On Things in General," the following two questions : — " If there is no fine art in photography, how is it that it is possible to produce by photo- graphy a scene, a view, or a representation that no artist can tell by simple inspection whether it is an engraving in one class, or a sepia or monochrome painting in another ? Secondly, if a painter of repute took pains to learn photography, would or would not some of his results be more artistic tlian those of the photographer with no art education ?" In answer of the first question I say that, in about thirty years, the time I am connected with photography, I never have seen a pliotograph which could not be recognised as such, or mistaken by an artist for an engraving, or a sepia, or monochrome painting. To the second query I reply that, by arrangement, by posing, Ac, an artist would be able to improve a representation, but would never be able to make photo/iraphy more artistic than a photographer without art education. — I am, yours, &c., F. B. SUGGESTIONS FOB AN EXPEEIMENT. To the Editor. Sib, — If it has not yet been tried and reported upon, I beg to suggest an experiment which may prove interesting, and perhaps instructive, to users of dry plates. Take two plates, coated one with slow, the other with rapid emulsion. Place them in contact, film to film ; expose, as follows, in the camera, under conditions similar to what would be used for a Sandell plate : — {a) Present glass side of rapid plate for exposure. (6) With a second couple expose glass side of slow plate. (c) After exposure, sepaiate the plates and develop. A further variation might be made by using three plates on thin glass — or, better still, three celluloid films — coated each with a different emul- sion, slow, medium, and rapid, tho medium being sandwiched between the other two. Experiments could also be made with orthochromatio plates. I have not myself the time at present to make experiments, bat I throw out the above suggestion for others to use if they see fit, and trust they will give the photographic fraternity the benefit of any knowledge acquired. — ^I am, yours, &o., Duncan C. Da 5, Furnival-street, London, E.G., April 15, 1893. DETERMINATION OF THE SPEED OF PLATES. To the Editor. Sib, — The above gives such a lot of jottings that I look in vain for » critique to the point from " Cosmos." I prepared my own dry plates at 270 THE BRITISH JOURNAL OF PHOTOGRAPHY. [April 28, 1893 home for five years (5 lb. a batch), therefore know from experience that fresh plates are more sensitive than older ones. The difference in the first two or three weeks is sometimes remarkable ; there is also a dit- :ference in the plates first coated and those done last, also each corner of the drying room imparts a different character to the plate. Well, I can't ■see the way out of the dilemma— that a once tested plate is condemned to bear the once given test numbers. Kindly excuse one who only axpects possibilities, and is content to remain-^ Yours, (fee, Apnl 21, 1893. Audacious Opbbatob. To the Editob. Sib,— In their article in this week's British Journai, of Photoobapht, Messrs. Hurler & Driffield write that, after making five experiments, I have satisfied myself that all their hundreds of experiments go for -nothing, and that their conclusions are erroneous. That, however, is far from being a correct description of the opinions I have formed. Messrs. Hurter & Driffield's investigations covered a wide field, and they have done a service to photography which I should be the last to underrate. They have investigated matters which badly need elucidation, and have made an excellent beginning towards placing on true scientific bases such matters as the connexion between exposure and density, ifec. I may add also that I fully appreciate the value of Messrs. Hurter & Driffield's system of experimenting, and have not hesitated to employ it in my recent experiments. Their original paper described almost the first attempt to make ma'tters clear in the branch of photographic science dealt with, and it has been a most valuable contribution towards that ■end ; but it is very improbable that every conclusion which the two experimenters arrived at, in a new and difficult line of investigation, will prove to be beyond criticism, and it would be but a poor compliment to ihem if photographers simply swallowed the paper as a whole, and abstained from pointing out what appeared to be doubtful features in the reasoning, or felt any hesitation in otherwise testing their results. After carefully studying their paper, my greatest doubts have been, firstly, in regard to certain theoretical questions on which there was some discus- sion last year in The British Journal of Photography ; and, secondly, as to the correctness of some of their conclusions on what they consider a matter of secondary importance, viz., the influence of development. Their conclusions on that subject are laid down very broadly in the original paper, and quite without qualification. They claim to have shown conclusively that in development the photographer has " no control whatever over the gradations of the negative," and the following expressions occur in the paper :^" The ratio of densities is given by light alone, and is not affected by time of development." " This ratio we find is altogether unalterable." " These experiments all confirm the state- ment that the gradations of a negative as expressed by the ratios of the densities, are independent of time of development, cannot be effected by alterations in the composition of developers, and are almost identically the same whatever developer is employed." Now, these are opinions which I believe my experiments have shown will require serious modifi- cation. In fact, Messrs. Hurter & Driffield scarcely seem to insist that the ratios are independent of the time of development, but admit the existence of a "lagging stage," and only express the opinion that, after sufficiently prolonged development, their principles will be found in all cases to apply. That may be, but how can it now be maintained that the ratios are " independent of the time of development ? " The principal subject which engaged my attention in my recent ex- periments (four out of the five being wholly directed to it, except that the effect of time of development on gradation was in one instance examined) was a comparison of the action of two pyro developers of widely different composition, and I found in every case that there were very great dif- ferences between the gradations produced by one developer as compared with those produced by the other. In the fifth experiment the actions of several species of developers, mixed in normal proportions, were com- pared, and, as I implied in the article, did not show results which differed very greatly from what might have been expected on Messrs. Hurter & Driffield's principles; but, as my object was not that of " simply opposing their views at all hazards," I thought I ought to publish an account of the experiment, as any results which help us towards forming correct opinions on these matters are not without value. I certainly expressed an opinion that, on other plates than the " Ilford Ordinary," greater variation in results might possibly be shown, and that opinion is now greatly strengthened, owing to an advertisement in yesterday's British Journai, of Photography, in which Messrs. Marion & Co. announce that, in the case of two of the developers experimented with, viz., eikonogen and amidol, it is found that their plates require less than normal exposure, and that the actinograph number may be taken from one-third to one-half higher when those (among other) developers are employed. There is a trifling misprint in my article which it may be well to mention. In summing up the conclusions I had formed, I wrote — or intended to write — " On the whole, the experiments show," &c., but the last two words are printed, " experiment shows," making it appear that I was referring only to plate E. My previous remarks will, perhaps, explain why I do not find the first table given by Messrs. Hurter & Driffield, in their last article, very in- ■structive. I have described experiments made almost solely for the purpose of comparing the action of two developers, and they give a table in which is compared the densities of all the strips developed with (me only of the mixtures, simply showing that strips which have had similar treatment have similar gradation ; there are also added the densities of the strips produced in an experiment on which I had laid very little stress, and Messrs. Hurter & Driffield consider that the ratios of the gradations of all the strips agree fairly well. Considering, however, that the figures on the first line vary between thirteen per cent, and thirty per cent., and also that there is great irregularity in the amount of reversal, I do not see much evidence of uniformity in the gradation. The sources of error mentioned by Messrs. Hurter & Driffield might, of course, account for great differences in gradation between strips cut from different plates, especially as it was never intended, when making the experiments, that the strips used in one should be compared with those of another, but such differences might tell either way. To return to my article, I think any reader of it who compares the results given by developer No. 1 with those of No. 2, or examines the various ratios of plate D, will admit that gradation — at any rate, over a wide range — may be much infiuenoed by the method of development, and if so, the statements given in Messrs. Hurter & Driffield's original paper require modification. In fact, these principles already appear to be undergoing modification. We now have the idea accepted that a "lagging stage" exists, and that being admitted, it is clear it can be no longer maintained that the alterations in density which occur during the progress of development may, as stated in the paper, be accurately represented by simply giving successively increased values to the factor y of Messrs. Hurter & Driffield's two formulte. It really appears to be scarcely contested that gradation over a wide scale of exposures may be modified, but it is doubted whether any alteration can be made by means of development in the small range constituting the " period of correct representation." To settle that point, as I stated in my article, far more elaborate experiments than mine would be necessary, and I do not think the published experiments of Messrs. Hurter & Driffield dispose of the question ; but it seems improbable that that part of the scale, and that only, should be invariable in the ratio of its gradations. In any case, other parts of the scale are also interesting, for those " extraordinary " photographers who sometimes make errors in exposure are, I believe, far more numerous than Messrs. Hurter & Driffield appear to suppose, and it is important to most of us to find how we can obtain the best possible results on a wrongly exposed plate. I am sure, at any rate, it is to hand- camera workers. The experiments which Messrs. Hurter & Driffield intend to make as to correcting under or over-exposure will certainly, like all others of theirs, be very interesting. My supposed oversight in describing the No. 1 mixture as excellently suited for developing under-exposed negatives, and not noticing that others which I had used were equally good (a questionable point), may be easily explained. My statement was not that it was excellent for the purpose, but that it was far superior to No. 2, a point on which there can hardly be a difference of opinion. The proposed method of saving a much over-exposed plate by stopping the development at an early stage and afterwards intensifying, is regarded by Messrs. Hurter & Driffield as an impossible one, because the intensification would, at most, only double the densities, and that in the instance given would be an in- sufficient increase ; but they overlook the fact that, as Mr. Chapman Jones has recently pointed out, the process may be repeated more than once. There is also another possible alternative, viz., reproduction of the negative. In conclusion, I may say that my state of despair is not quite so deep as Messrs. Hurter & Driffield suppose, and in writing that development seemed likely to remain a mere rule-of-thumb matter, I did not mean that I was without hope of that unsatisfactory state of things being at last remedied. That hope is much strengthened by learning that Messrs. Hurter & Driffield will endeavour to come to the rescue, and are not therefore deterred, as I feared they would be, from further investigations by the belief that nothing more remained to be discovered. They are not, I presume then, still of opinion that nothing can be changed by varying the composition of the developer, or time of development, except the value of the simple factor y. — I am, yours, etc., H. J. Channon. li'oodlands, Lewisham, S.E., April 22, 1893. THE TOOTING CAMERA CLUB. To the Editor. Sir, — I think that it is my duty to call the special attention of photo- graphers who may reside in the neighbourhood of Balham, Streathara, Wandsworth, &o., to the announcement made in this week's report of the Tooting Camera Club, viz., tliat we shall hereafter have our own meeting and dark rooms, situated in High -street. Tooting (near the tram terminus), being both central and convenient of access. Few of the London clubs have the same facilities as we shall soon be in possession of, and photographers who would like to share the same, but are unacquainted with any of our members, should write to me at the undermentioned address. — I am, yours, etc., J. F. Chuj), Hon. Scl: Harzville, Leigham Valley-road, Streathavu April 28, 1893] THE BRITISH JOURNAL OF PHOTOGRAPHY. 271 "OPEN HOUSE." To the Editob. F Sir,— The Society of Amateur Photographers of New York desire to extend the lioapitality and use of their rooms to all amateur photo- graphers who intend visiting the World's Fair at Chicago, and who will pass through New York daring the coming summer.— I am, yours, Ac, T. J. Bdbton, Secretary. Society of Amateur Photographert of New York, 113, West Thirly-eighthstreet, New York, April 15, 1893. " MUTATO NOMINE," Ac. To the Editob. Sir,— The following fragment of a fable which has come into my possession may, at the present moment, interest a portion of your readers. Tire KiKQ AND His Puts. "There once lived a good-natured king who delighted to entertain all the .-mirnals which roamed around his palace ; so from time to time he in tiun invited them to his mighty dwelling-place, and feasted them right royally with rare viands, garnisiied with silver and with gold. And all were exceeding glad, except some of a very wonderful sort that mostly went on three legs and had each but one eye. These, having for a while enjoyed full share of the good fare, yearned for still better, and, moreover, they became wroth and forward that they were not, while in his glittering palace, even as was the king himself. And so, said they, ' although it he garnished with gold and silver, we will not eat of his food unless he bow the knee to us.' Therefore they stayed without in the wilderness, and, a blight falling upon the land, the fruits of the earth were scanty, and it came about that " Most provokingly the MS. breaks off at the most interesting part. Your readers may, however, possibly find profitable entertainment in trying to supply the missing words. — I am, yours, &c., HeCIOB MACLKAlf. 34 Newmount-road, Croydon, April 18, 1893. gelatino-chloride versus albumen. To the Editor. Sib, — My experiences with the gelatino-chloride papers are as follows — I find no difficulty in the manipulation up to the finishing of the prints ; I then find the surface has such an affinity for specks and dirt adhering to it, that it takes much longer time to touch and finish up than albu- menised paper ; but any speck is easier removed with spirits of wine than water, which destroy the surface. With a bar burnisher it is impossible to avoid spoiling some cards, as they get scraped like enclosed copy — not the ordinary " scratch." This alone makes me throw the paper aside meantime. With the gelatino-chloride papers I obtain a more brilliant print from a negative if wanting in contrast or density than with alhumenised paper. That is the only advantage I find unless there is any on the score of permanence, which time will tell. I have also used the ready-sensitised paper to some extent. The great drawback to it is the rapidity with which the prints spoil that is made on it. The same mottled marking soon appears on the print that shows on the paper when it is kept any time and printed. The mottling more readily develops when prints are put in a show-case, or where they have a chance of damp and are soon spoiled. I think there is nothing yet to beat the " home-prepared " alhumenised paper for good results. I have carefully read all that has been written on printing papers in the Journal, and would be glad to see more on the subject from workers. I only write in the interests of the profession. — I am, yours, il'c, April 20, 1893. B. B. [Experienced workers do not find any difficulties with gelatino- chloride papers such as those met with by our correspondent ; but, for the benefit of professional photographers, we should be glad to • .pen our columns to an exchange of views on the subject. — Ed.J BEABD'S BEOULATOB. To the Editob, Sib, — I regret that I cannot answer Mr. Walker's questions regarding Beard's regulator, as I have no recollection of its structure, unless it WM the one that got a medal at Falmouth a number of years ago. It had a spindle through a flexible diaphragm. There was a weight on the top of spindle, and a valve at its lower end. It was almost a facsimile of one that a Mr. Broughton, of Fountainbridge, near Edinburgh, had patented many years previously. They were used for some time on the street lamps in Glasgow. Beforo|taking out a patent for my regulator, I satisfied myself that tie keyed cock was superior to a valve, as the former will last a lifetime. Regarding the anti-friction cock, although I have them on the apparatus I use myself, it is not patented yet, although I have got permission that they may be used wherever the Glasgow is used. I will send Mr. Walker a drawing when I get it patented. — I am, yours, ic, Airdrie, April 24, 1893. WnjJtAM Bibbbll. AMIDOL. To the Editor. Sir, — Will you kindly allow me space in your next issue to reply very briefly to a remark by "Cosmos" in last week's "Jottings" respecting amidol. He refers to a statement by Mr. Peal, of Ealing, that exposure can be reduced two-thirds the usual duration if amidol is used to develop, and asks for experimental evidence in support of that statement. Mr. Peal will, doubtless, answer for himself, and I must offer him my apologies for attempting to reply to a question addressed directly to him ; but, as I have publicly for several months been making an identical claim on behalf of amidol, I may, perhaps, be excused for interfering in the matter. Having had a fairly extensive experience of the properties of amidol, I can fully confirm Mr. Peal's opinion, and have also had confirmation of the statement from several professional photographers in various parts of the country who have taken up amidol in preference to pyro. To put the matter simply, the claim for amidol is that, if under ordinary con- ditions the necessary exposure (using pyro) is, say, three seconds, an. exposure of one second will give an equally good result if amidol is used to develop. You can do it, " Cosmos," but don't take my word for it ; give it a fair trial, and report the result. — I am, yours, *c., L. E. Morgan. IT, I'hilpot-lane, London, E.G., April 25, 1893. sanstoew to OTorresponTienig. ,* All matters intended for the text portion of this Jocbnal, including queries and Exchanges, must he addressed to " The Editor, The British Journal of Photography," 2, York-street, Covent Garden, London, In- attention to this ensures delay. »* Correspondents are informed that we cannot undertake to answer com- munications through the post, »* Communications relating to Advertisements and general business affairs should be addressed to Messrs. Henry Greenwood k Co., 2 York-street, Covent Garden, London. Photooraph Ekqistered : Abraham Flatters, 6 Pen^haw.- -Thiriy photographs of cotton fibre. THE CAMERA. CLUB PAPEBS. To the Editor. Sin, — As from comments in your valuable Journal there appears to he some misunderstanding in regard to the publication of papers read at the Camera Club, will you kindly allow me to state that, although all rights are reserved as regards copying, the public are not debarred from access to the papers, inasmuch as the full Conference Journal will be published by Jlessrs. Harrison & Sons as usual, and all important papers from the ordinary monthly issues of the Club Journal will be issued separately in pamphlet form (by the same publishers) available far subscribers. — I am, yours, etc., G. Davison, /Zon. Sec. Camera Club, Charing Croes-road, W.C, April 24, 1893. RuDD & Co.— The Convention group at Edinburgh was taken by an Optimus rapid rectilinear. " Dry Plates " for April contains an article by Mr. Cadett on " The Fixing Bath " of much practical value. R. Childs. — The formula for the caramel backing solution is given at page 221 of the Journal for April 7. Rocks.— It appears tons that the bottom of the picture is so poorly lighted that it is under-exposed. Could you not manage to throw a little more direct or reflected light upon it ? W. E. W. — Either the prints were developed with iron which was not removed, or they were acid when placed in the fixing bath. Anyhow, they show want of care in the manipulations. J. Gbaha-m. — 1. We are of opinion that the combined bath will yield quite aa permanent prints as the other. 2. Tlie lens you mention will answer well for architectural work in addition to the other properties. Staffs. — Unless you have made the views copyright in the usual way, you have no redress against the lithographic piracies "made in Germany. ' If you had a copyright, you could proceed against any one selling the piracies. T. R. (Bombay). — A difficulty is frequently experienced in obtaining density in some brands of extra-rapid plates. But by increasing the proportion of pyro considerably, and slightly the bromide, the trouble can generally bo surinouuted. 272 THE BRITISH JOURNAL OF PHOTOGRAPHY. [April 28, 1893 X. Y. Z.— We think that by substitutiug for the small lens C a triple achro- matic, such as is empleyed as an eye-piece in the better class of opera and field glasses, there would not be any fringes of colour apparent. It would be worth while trying this. B. K. C— We are uncertain as to the nature of the effects desired to be produced, therefore cannot aid you. Bearing in mind, however, that the angles of inci- dence and of reflection are equal, you will be enabled to construct a multiple reflector, if it be this at whicli you aim. D. E. GODDARD.— This week's report of the London and Provincial Photo- graphic j\ssociatiou's meeting, and Mr. Cowan's paper in reply to Mr. Williams, published in another part of the Jockxai., continue the subject of the detennination of plate speeds. J. P.— The markings on the negative look like hypo, which has recrystallised out through imperfect washing. You might try the effect of removing the varnish with alcohol, and of reflxing in strong hypo, but we are not very hopeful that the negative could be saved in that or any way. E. E. C. (Innsbruck).— So far as one can judge from tlie print, the negatives are much over-exposed. If all hare received approximately the same exposure, treat them as being over-exposed when developing. Evidently the Alpine light has misled you. Still, with care, the negatives need not be lost. Oktho. — Instead of seeking for one of the aniline colours for giving to the prints the apjiearauce of old engravings on Indian paper, try the effect of a decoction of coifee, strength according to the tint desired. None of the coal- tar colours occur to our mind at the moment that would answer so well as the coffee. Tissue. — When the bichromate bath becomes discoloured and frothy, as you describe it, it should be discarded and a new one made. It is not necessary to strengthen it as in the case of a silver bath, neither is it desirable to use the bath until it becomes in the state referred to. Bichromate of potash is cheap enough. H. Wade. — 1. The simplest way to add to the density of carbon transparencies is to treat them with a solution of permanganate of potash — say, ten grains to the ounce of water. 2. See .answer to R. Fortune. 3. The ordinary sp.lphate of copper of commerce is the kind emijloyed in making the bath for electro deposition. B. Browx, M.D. — In your preliminary experiments, confine yourself to low powers, say an inch or an inch and a half. The arrangement of the apparatus, a.s shown in the sketch, cannot be improved upon. Do not attempt objects with much colour till some little insight on the work has been gained. " Ordinary " plates to begin with. W. E. Patehson. — There may be two reasons why the enamel collodion dries with a crapy texture : First, the employment of a pjTOxyline of an unsuit- able kind; second, using solvents containing too large a proportion of water — i.e., not strong enough. With a suitable sample of pyroxyline, and methylated ether of s.g. -715 or 720, and methylated alcohol of66o.p., a good collodion for enamelling paper prints will be obtained. For this purpose the presence of the mineral naphtha will do no harm. M. L. — 1. AH the processes mentioned are capable of giving good results. As you have failed with them, you might employ the plan of placing a mirror at an angle of 45°with the lens when taking the negative. 2. The Kallitype process has answered well for portraits in this country. 3. Schirm'.s Hash- lamp may, we believe, be obtained from Mr. Remain Talbot, Berlin, 4. Mr. Slingsby, of Lincoln, and many other portrait pliotographers, employ the flashlight very successfully in the .studio. Messrs. Marion & Co. will supply you with information on the subject. J. HiBiis. — Steel facing of copper plate is an electrotyping process, and its object is to enable a larger number of fine impressions to be obtained from the plate than could be obtained from the bare copper. In fact, by this H process, the copper plate becomes almost everlasting. A coating of iron of extreme thinness and great hardness is deposited on the engraved plate, which prevents wear of the copi:ier in printing. When the iron shows signs of wearing through, the coating can be taken off, leaving the copper in its original condition, and a new one deposited as at first. T. 0. J. says : " Can you tell me of anything that I can add to a solution of gum Arabic, which my hands use for spotting prints, that will keep it from becoming sour. I know that carbolic acid will answer the purpose, and I am using it, but the girls complain that they cannot use the lips for drawing the brush to a point with that in it." — A small ])roportion of alcohol will answer quite as well, and it will make the mucilage more palatable. Methy- lated spirit will answer, but perhaps young ladies will protest against its use. Anyhow, a very small proportion of the pure spirit will .suflice. C. Macek asks if the electric light, arc light, can be used for printing on the Ilford Printing-out paper ; and, if so, what would the exposure be ? — The light could be used, but it would necessarily make the printing very ex- pensive in comparison with daylight, which costs nothing. Tlie exposure will, of course, be dependent upon the power of the light used and the density of the negatives. From a commercial point of view — and it is upon this, we imagine, our correspondent's query is based— the thing may be con- sidered as impracticable, except, perhaps, in an extreme case occasionally. E. S. .J. writes : "I have often seen it stated that professional photographers generally sensitise their own paper, because, on it, they get better results than amateurs do on what they buy ready-sensitised. For some time past I have been sensitising my own paper, using a fifty grain bath, and I much prefer it to that bought ready-sensitised ; but I am much bothered at times with dark marbled-like markings on the paper when it is taken 6ff the bath. . One or two sheets will be so, and then all the others will be clear. What can be the cause ? " — If the bath is allowed to stand in the dish, a scum foims on the surl'ace, and, unless this is removed with a strip of blotting- paper, it will be taken off by the albumen paper. Skim the bath before floatiDg the paper. P. Seville writes : "Can you tell me how to prevent the black spots which are on the enclosed photograph. It is printed on Ilford P.O.P. They make their appearance in the first washing water and by no after-process have I been able to get rid of them. One photographic chemist recommended to filter the water tlirough a very fine flannel, but it made no difference. I liave tried constant running water whilst washing them, but still spots appear. If the prints are allowed to lie still in the water for a moment, I have some- times noticed a black deposit on them, which I have immediately removed ; but every print so attacked has been quite spoiled. From this cause I hare had spoiled as many as forty vignettes in one week. If you can suggest a remedy, I shall be exceedingly obliged to you." — The spots are due to par- ticles of foreign matter, which coming in contact with the paper reduces the silver. These particles must be either in the water or on the surface of the print when it is immersed in it. Robert Fortune writes : " Would you please answer the following questions ? 1. After having developed a carbon pnnt upon a sheet of coUodionised glass, can you tell me how to dissolve away the collodion film without injury to the carbon print ? 2. Can you tell me where to get a price-list of the copper plates, press, &c., necessary for photogravure .' 3. Can you give me the formula for etching upon glass, commonly called a 'dull bite?' It is "done by suspending the glass in the vapour of certain chemicals. I think it is a mixture of hydrofluoric acid and ammonia, but cannot say for certain. 4. Can you tell me whefe to get bitumen or asphaltum which is sensitive to light, and what is the solvent used after exposure to dissolve the parts which are still soluble ?" — In reply : 1. Before the collodion can be removed, the print must be taken off the glass. Before applying the collodion, talc the glass ; then, after the print is developed, squeegee a thin sheet of gelatine upon it, and allow to dry. Remove the picture, and clean the collodion off with a mixture of ether and alcohol. 2. Any dealers in printer" materials, such as Hughes & Kimber's, Winston's, and others. 3. Placs some fluor spar at the bottom of an ebonite dish, moisten it with sulphuric acid, and place the glass to be etched over it. 4. Any wholesale chemistc Turpentine, to which sometimes a little benzole is added. Catalooues have been received from G. W. Wilsou & Co., Aberdeen, and W. Banks & Co., Bolton. PHOTOGRArmc Club. — May 3, Lenses for Copying. 10, Members' Open Night. Saturday outing. May 6, Eynesford. Messrs. Arthur Schwarz & Co. point out that we omitted to print their name as agents for Dr. Andresen's chemicals in their last week's letter about settlement of, the dispute between the manufacturers of the amidol. London and Provincial Photographic Association. — May 4, Technical Lecture of the Series — Developers, Mr. E. J. Wall, 11. Pai)er by Mr. W. H. Harrison, Is the Present ConstruMion of Photographic Studios Wrong in Principle f 18, Monthly Lantern Night. The Central Photographic Club. — The Hon. Secretaries of the Central Photographic Club (Messrs. W. Feuton Jones, 12, King Edward-Road, Hack- ney, .and C. H. Oakden, of 51, Melbourne-grove, East Dulwich) are open to receive applications for shares in the Club Company. The shares are U. each, 21. 10.?. being paid on allotment. All other comnmnications relating to the Club should be sent to those gentlemen, and not to Mr. Thom.as Bedding, who is no longer Hon. Secretarj' pro Icm. Photooraphbrs' Benevolent Association. — Meeting held in the rooms of the London and Provincial Photographic Association, Thursday, April 20, Mr. Robert Beckett in the chair. Two applications for assistance were considered by the Committee. — In one case a lo.in of 5/., together witli a further sum in instalments, was granted. In the other case, the Committee instructed the Secretary to refer the applicant, who was a foreigner, to the consul of his own country, and to state that his cise was one which the Committee did not see their way to relieve. The Rev. H. O. Morgan and Mr. J. G. Hndson were accepted as subscribers, and Mr. Walter D. Welford was elected a life governor. The Secretary rejiorted on the fact that the proceeds of the Sandell Exhibition had been devoted to the Benevolent, and annoimced that Mr. Sandell had expressed his willingness to loan the whole of the pictures from that Exhibi- tion, and to supjily a number of catalogues gratis to any provincial society that would organize an exhibition in its own town and give the proceeds to the Benevolent Association. The following subscriptions and donations were acknowledged: — Rev. H. G. Morgan, 5s.; Atticus, 10s. 6rf. ; Photographic Review of Revieios Charitable Fund, 2?. 2s. ; Hastings and St. Leonards Photo- graphic Society, 21. 2s.; Pholo(jraphy Prize Competition, 6s. ; Mr. J. 11. Hudson, 15s. ; Mr. Thomas Bedding (The British Journal of PH0T0GRAP^^). 10s. 6rf. : and Mr. R. Hayward, 7s. 6rf. *»* Owing to exceptional pressure on our space this week, we have been obliged to hold over several Society reports, letters, articles, and other interesting matter. We trust our numerous friends and correspondents who have been disappointed at the non-appearance of their communications will exercise their patience, for the reason given. OONTXIMTS, PERSPECTIVE IN PORTRAITURE 267 COMBINING ENLAROEMKNTS FROM DIFFKRENT NEOATA'ES 257 ALBUMKN BROMIDE PAPER FOR CONTACT PRINTING. By W. B. BOLTON 259 AMERICAN NOTES AND NEWS STO PHOTOGRAPHIC METASTASIS. By HUGH BREBNER 261 DETERMINATION OF PLATE SPEEDS. By ALEXANDER. COWAN 262 Paos THE MULTIPOTENT CAHTERA. T. E. HEATH OUR EDITORIAL TABLE IfA RECENT PATENTS M4 MEETINGS OF SOCIETIES MS FORTHCOMING EXHIBITIONS 2«5 EXCHANGE COLU.MN 2W CORRESPONDENCE 20' ANaW£B8.I0 COBKESF0NDENT8 271 THE BRITISH JOURNAL OF PHOTOGRAPHY. No. 1722. Vol. XL.— MAY 5, 1893. FOCAL PECULIARITIES OF WIDE-ANGLE LENSES. Fa-erv one who is accquainted with the most elementary principles of optics as affecting photographic lenses knows that •a deep meniscus lens will not, unless it be stopped down to a considerable extent, give an image at the focal plane any part of which is sliarp, and that, the more pronounced the meniscus form is, the smaller will have to be the stop or diaphragm requisite to minimise the spherical aberration by which sharp definition is prevented. This applies, not alone to a single meniscus, whether achromatised or left uncorrected for colour, but is also the case when two such forms of lenses are mounted together so as to form a wide-angle, non-distorting objective. When an objective of this class, single or compound, is focussed with its largest available aperture, say, for example, /•lo, upon any suitable object, so as to produce the sharpest image of which it is capalale under the circumstances, and a very small diaphragm is then inserted, disappointment is apt to be experienced at the small gain in sharpness that has resulted. It is a common habit with those who employ lenses of this nature to focus with the largest diaphragm supplied, and then use one much smaller for making the exposure. For this there Is a certain excuse which is plausible although not valid, viz., that a wide-angle lens of short focus admits an insufficiency of light to permit of any focussing being effected with a small stop, and that hence the largest one must be made to serve the purpose both of arranging the subject on the ground glass, and also of focussing ; and it is reasoned that after this has been done the sharpness will be increased by the insertion of the small or working stop. But it must be borne in mind that, when working thus, there are two focal planes situated at a certain distance apart, the one for the largest stop being closer to the lens than when the smallest one is employed. Hence a readjustment of the focus is imperatively demanded between the focussing with the large and the exposure with the small diaphragm. A clever casuist may say that, if he makes the image sharp with the larger aperture, the reduction of the aperture cannot make the image less sharp, seeing that the same rays by which the ■former was produced are utilised in the production of the latter. To which we reply, that we deny the acme of sharpness in the first case, on account of the amount of spherical aberration present, for, be the focussing cfTectod with the utmost care, there are still transmitted rays which cross the axis at a greater distance than the mass of those by which the image is formed, 'f And it is ouly when the lens is aplanatic (which no wide-angle deep meniscus ever is) that all the rays cross the axis at one point. We repeat what has already been said, that, in order to obtain the extreme of definition when employing only those attenuated rays transmitted by the small diaphragm, the focussing screen must be placed in the plane at which they cross the axis, and which, as we have said, is at a greater distance from the lens than is the case when the bundle of rays is larger. Practice supports theory in this. We have just made a series of careful tests relative thereto, and have employed for the purpose a wide-angle deep meniscus combination of the most recent construction, and bearing an honoured name. The solar focus is eight inches, and the largest stop equals /-1 6. We focussed upon the meshes of a piece of rather fine network, such as that employed for window curtains, using a Ramsden eyepiece carefully adjusted and attached to the ground glass of the camera. The camera was thirteen feet distant from the network, which was erected so as to be backed by the sky. Having got the greatest sharpness capable of being obtained with the stop mentioned, we marked on the camera the stage to which it had been extended, and then "Turned on" the/-32 stop and focussed again. There was a very marked increase in the definition of the lace, which was exceedingly crisp and sharp, the meshes being as if cut with a finely pointed graver. Another mark was now made on the camera. The /-1 6 stop was then made to supplant the /-32 one, and the image again examined, revealing now a serious falling off in sharpness. This was repeated several times, and established the fact that for the apertures mentioned there were two focal planes. On measuring the distance apart of one mark on the camera from the other, it was found to be three-sixteenths of an inch. We have entered into this matter somewhat at length in order to enforce advice we have repeatedly given, and which is to the effect that, while the largest possible aperture of the lens is by far the most convenient to make use of when arranging the subject on the focussing screen, it is of vital importance where the highest degree of definition is desired that the focussing be effected when using the same stop as that by which the photograph is to be made. When the lens partakes more of the aplanatic character than the deep meniscus that we have been describing, the same amount of difference in the focal planes does not exist, and we have seen lenses of the " rapid " class in which the focal plane with tlie full aperture and that with the smallest stop showed no mai'ked difference between them. Lenses of this type, however, are not capable of including an angle of view so great as those of the deep meniscus form. Just observe the axial e.xcellence of definition of the highest type of 274 THE BRITISH JOURNAL OF PHOTOGRAPHY. [May 5, 1893 planatic lens that is known — the object-glass of an astro- nomical telescope; by no amount of stopping down can its defining power be improved, but, on the contrary, it rather deteriorates. In it the amount of spherical aberration left uncorrected is practically non-existent. The external form of such a lens when made of ordinary optical glass is that kuown as crossed, which, while right for axial rays, is hostile to the transmission of oblique ones, for which pur- pose we must have recourse to lenses of meniscus form. The deeper the meniscus form the better is an extremely oblique ray transmitted, and hence the necessity of the deep meniscus for wide-angle lenses, which, on account of the aberration of sphericity, renders a small stop imperative. It is no fiiult in the construction of such objectives as we have been speaking of that there is the difference spoken of between their foci when using a large stop contrasted with a small one. It is an optical necessity of their construction. We have known of more than one who made a speciality of copying fine line engravings of large dimensions who adjusted and focussed with a large stop on account of the superior illumination, and then inserted a small one, and who, failing to get the sharpness desired, blamed the lens, and laid it aside, whereas the fault lay with themselves in not knowing how to use such a lens aright. We hope that, from a perusal of what we have written, they will be able to do so in future. A writer on the subject of focussing, eight years since, said: " To focus with the working aperture, as some writers recom- mend, is not only useless, unless the lens is imperfect, but it is practically impossible with the small apertures required for the rapid plates now used." We have adduced suflBcient evidence to show the utility of the course recommended, and have only to add that if, owing to the feeble light transmitted through the smallest stop, correct focussing is not possible with its use, this can be ensured by the expedient of focussing with a large stop, and racking the camera out the extent necessary, and which has been previously ascertained by ex- periment, to ensure absolute definition by the small or working stop. Photographers should study the peculiarities of each lens they employ. GUMS AND GLUES. The query put by " T. 0. J.," and replied to in our last, sug- gests the usefulness of a few hints on the use of gums and gelatines in their more mechanical aspects, so to speak, in relation to photographic manipulations. xVcacia gum is so largely employed for the purposes referred to in our corre- spondent's query, that it is not surprising he has met with the commonly experienced difficulty. Any one feeling similarly troubled may with advantage act upon our suggestion of the use of a little alcohol, the best way of adding which preserva- tive is in dilute solution in water, a thicker gum mixture being then made to avoid undue thinning. If alcohol be added direct, it will cause clots to form which will not readily redis- solve. In making "gum water," which perhaps is done in every studio in the country, there are some minor precautions to be taken which will obviate the acidity or sourness for a time at least. First may be mentioned the advisability of dissolving the gum in perfectly cold water. Hot water is generally used, and the solution, in consequence, invariably decomposes in a day or two, especially in hot weather. Those who have not adopted this method will be surprised at the difference in smell even when first made ; there is an actual fragrance about the cold solution which is entirely absent when heat is employed. Then, again, it is quite unnecessary — a useless addition to the expense, in fact — to use, as some do, the powdered gum. Nice clear, clean, pale lumps should be chosen, though the kind sold under the technical name of " sorts," which includes white and coloured pieces, is quite as good, though not so pale in solution. An excellent plan to adopt is to make a quantity at once, and then place it in small bottles made quite full, and then well corked and kept in a cool place. So prepared, it will keep fresh quite a long time. There are many substances that can be added to act as preservatives, which are quite out of question, when the gum wajter is to be used for spotting, on account of their taste. Of the least objectionable, sulphate of quinine stands foremost, so very small a quantity being required : indeed, we doubt whether the bitter would be noticed. Gum water made very thick is a most useful and handy mountant, but its great draw- back is the liability to cause a greasy appearance in the print wherever the finger is laid and pressed upon the gummed surface before mounting. It is stated that this effect may be got rid of by adding sulphate of alumina in solution, three per cent, of the weight of the solid gam being added. An excellent substitute for gum water is made from milk ; the caseine is precipitated by acetic acid, well washed till freed from acid, and then dissolved in a saturated solution of borax. We believe we are correct in saying that a solution of gum arable or acacia was the first mountant used in dry mounting. We remember seeing it in use at Disderi's establishment in Brompton about twenty-five years ago, and some prefer it to | this day on account of the ease with which it is made to adliere under what would be unsatisfiictory conditions for other materials Perhaps, where it is prepared, it might for this purpose be better to use the formula given to us by a label- manufacturer in which gelatine plays a part. It is as follows : — One pound of gum arable, one and a half pounds of gelatine, one ounce of sugar candy, six pints of water. The gelatine to be first soaked in a little water, and then melted in the rest of the water in which the gum and sugar candy have first been dis- solved. The difliculty of dry mounting is that, if there is not complete adherence, the print may blister when heated by burnisher or hot process. Some blistere, however, that appear when first mounted may go down in the hot press. Where a small pot of gum is handy for occasional instant use as a mountant, " gum water," as gum-arabic solution is usually termed, is a decided favourite ; but we strongly advise a mucilage of tragacanth gum. This is strongly adhesive, and is free from the objectionable tendency of "greasing" the print where pressed by the finger, the effect not being due, of course, to grease ; yet the appearance is just as though some oleaginous matter had been spilt there, and it has been a puzzle to many a one who has only occasionally used the solution. The drawback to the use of tragacanth is the great tendency it possesses to go mouldy. Many substances have been recommended to prevent this, the most successful being the essential oils — oil of clove, for instance. It has been stated that boric acid, which is so admirable a preventive of mould in many cases, will answer ; but our own experience entirely negatives the assertion. We left a small pot of tragacanth, to which we had added boric acid, lightly corked in a free draught of air, and it was covered with mould in a fortnight. Salicylic acid preserved another sample for a much longer period, and a mixture of thj-mol and the latter chemical kept the mixture pure and clean till it dried up to the consistency of horn. The smell of thymol would to Uray r>, 1893] THE imiTISH JOURNAL OF PHOTOGRA-PII Y. 276 some, perhaps, bo objectionable, though others consider it very fragrant. AVe have left ourselves no space to refer to glues or gelatines in photography, and will therefore consider their pro- perties in a future article. A Ziarg-e Ifog-ative.— Messrs. Wenier & Son, of DuMin, have riHentlj- takon direct fntm life a negative 64x38. It is, we under- stand, to be exhibited at Chicago. Po?sibly it is the largest direct negative ever taken. Silver BKedal Awards at Philadelphia.— This country has secured a liberal proportion of tlie silver medals awarded at this great American Exhibition. The names of the fortunate artists are Oeorge Bankart, Leicester: .lohn H. Gear, London; William Gill; Colchester; Karl Greger, London: Edgar G. Lee, Xewcastle-on-Tyne, R. H. J^ord, Cambrida'e ; W. P. Marsh, Bognor ; Charles Keid, Wishaw: Ralph AV. Robinson, Red Hill; F. Thurston, Luton; G. West & Son, Southsea : W. Clement AVilliams, Halifax, and W. W. Winter, Derby. The Royal Academy Exhibition.— The Royal Academy opened its doors to the pulilic on Monday. It is surprising how com- paratively few photographers consider it worth while to visit its iimiual Exhibitions, considering there is always something to learn therefrom. As usual, several of the pictures in the present collection are greatly indebted to pliotography. Especially is this the case with portraitp. Of course, this is not mentioned in the catalogue. .lust now, in addition to the Royal Academy, several other picture exhibi- tions are open. There is the New Gallery, Royal Society of British Artists, Royal Society of Painters in Water Colours, and others, all of which might he profitably visited by the majority of photographers. "At Xiast, Colour Photography." — This appears on -ome pictures exhibited for sale at a printseller's shop in one of the leading thoroughfares of the City. The pictures are in colours produced mechanically, are very indifferent, and the announcement is certainly misleading to the general public. This is proved by the fact Q that on two occasions we heard persons discussing the merits of the pictures as if they really were photographs taken in their natural colours. One remarked. " They have been trying at it for years, and now they have got it," adding, in reply to a comment as to the mediocre character of the work, " Yes ; but, now that they have found out the way, they will soon make improvements upon it.'' The public have so often been told that the discovery of taking photographs in natural colours has been made, that " at last " some are easily misled by the above announcement. Success of the Eclipse Expeditions.— It is gratifying to astronomers to know tliat the two English expeditions — the one to the West Coast of Africa and the other to Brazil — have both been successful in their photograpliic work. A few days back Dr. Ainslie Common, secretary to the joint Eclipse Committee of the Royal Astro- nomical Societies, received a telegram from Mr. Taylor, who had charge of the Brazil expedition, saying that the negatives taken with the chronograph and with both spectroscopes have been developed, and that they are quite successful. It will bo remembered that similar success, witli like instruments, on the West Coast had previously been announced. Expeditions from other countries have also been, for the most part, highly successful. It is not always tlie case in these events that the weather is as propitious as it was on this occasion. The results will certainly he of great value to astronomical science. Stripping- Megratlves. — A question was put at a recent meeting of one of the metropolitan Societies as to how to strip a negative from the glass without the film expanding. The replies given were, however, not very definite. Now, if the negative be developed with pyrogallic acid, and is afterwards well alumed, the film, when removed, will hsve very little tendency to expand. If, however, expansion does occur, the film can at once he brought back to its original dimensions by immersing it in alcohol. Indeed, in some cases, when very strong spirit is used, it can be reduced below its original size. When extreme accuracy as to size is imperative, it is advisable to protect the film from expansion while it is in a moist condition, either by coating it with a thick film of collodion or with gelatined and indiarubber paper. Then, when the stripped film is dry, the protecting medium can pe removed. Details of each method of working will be found in our Almanac for 1889. Both methods are worked commercially when stripped films are required. Portraits and the School Board.— At the meeting of the London School Board last week, the question was asked by whose authority certain " hideous pictures " had been placed in the new Board-room. The reply was that the architect proposed to insert in tlie lunettes of the Board-room the effigies of Archimedes and other ancient personages, and it was suggested that " portraits " of persons who were, or had been, on the Board would be preferable. Had the architect's idea been carried out, there is little doubt that the portraits of " ancient personages " would not have been so closely criticised as likenesses as are those that have been substituted. However, the living prototypes can scarcely feel flattered by the portraits that are to hand them down to School Board posterity being designated as " hideous pictures." Many board and committee rooms are adorned by portraits of former members ; but they are usually in the form of oil paintings or enlarged photographs, and not as " hideous pictures." American Appreciation of Eng-llsh Art Work.— It is satisfactory to find that the works of some artistic photographers in England appear to be highly appreciated in America. The pictures sent by Mr. George Davison to the Philadelphia Exhibition were too late in being delivered until after the work of judging had been ac- complished. This delay was occasioned by Custom-house red-tapeism, which surrounds with difficulty so many things that enter the United States. If, however, Mr. Davison has received no expression of opinion from the Judges, he is being awarded a not stinted amount of panegyric by the press, in fact the eulogiums on his work are of tne highest order. The Ihiblic Ledger ranks Mr. Davison as the foiemost exponent of the art side of photography in England, his work being now seen for the first time in America. From this paper we learn that it is Mr. Davison's custom to produce only one good print from a negative, so that each of his pictures is as unique in its way as a painting produced by an artist in colour. This is a trait in Mr. Davison's working of which we were not previously aware. The ex- hibits form a special loan collection, and are not entered for competi- tion. Many of the examples are made without a lens through a pinhole aperture. ♦ REDUCING OVER-PRINTED GELATINE PROOFS. Fob many years a perfect method of reducing over-printed albumen prints without spoiling the tone has been a desideratum, and, so far as I am aware, up to the present time has not yet been achieved. The mere reduction is a matter of the greatest ease by a variety of methods, but these, without exception, act more or less injuriously upon the colour of the gold-toned image, and rob it of the charm that rendered the " photographic purple " such a popular tone. With gelatine prints, however, the case is somewhat different, whether the image is the result of printing-out or of development, since the tone is almost invariably free from tliat warm tint that marked the albumen print, and which is so difficult to maintain under the action of reducing agents. The neutral black or cool grey tones of the modern gelatine print are, in fact, little, if at all, affected by such agents, except so far as lowering the strength of the image may affect its depth. This is especially fortunate, since the difficulty of stopping development at exactly the right point, as well as of judging the correct depth in the dim light of the dark room, is far greater than in examining the gradually progressing image of a direct print in feeble daylight. In his anxiety not to overdo the development, the operator is apt to err on the reverse side, and to discover when too late that the print is spoilt by under-development ; but, in the presence of an 276 THE BRITISH JOURNAL OF PHOTOGRAPHY. [May 5, 1893 efficient means of reduction, he may with safety, and even with actual advantage, allow the development to proceed beyond the depth desired, and then, after fLxing, and in a good light, proceed to reduce it at Ms leisure, and with everv power not only of carefully .judging the right depth, but also of stopping the action instantly when the proper point is reached. A further advantage may also be claimed, namely, that the process of reduction also serves the additional pur- pose of clearing the whites of the print, and removing developing stains, usually a separate operation, so that it can scarcely be said that the introduction of systematic over-printing and reduction adds anvthing to the labour involved. it is scarcely necessary to remark that there are a large number of different methods by which the reduction can be effected, but m making the selection of a perfect one, I should decidedly give the preference to one that consists of a single solution, that is to say, one that removes the excess of density in one operation, instead of re- quiring the application of a second solution to complete the process. Of the first class, the mixed solutions of ferridcyanide of potassium and hypo, or of ferridcyanide and sulphocyanide of ammonium may be mentioned as types, while the second class is represented ^by such applications as weak hydrochloric acid followed by hypo. So far as the actual reduction is concerned, nothing can excel the compound solutions containing potassium ferridcyanide, but they possess an unfortunate tendency in the direction of yellow stain — slight, it is true, but still sufficient to mar the beauty of an otherwise perfect print. Alum and hydrochloric acid— the ordinary clearing solution for negatives and prints — exercises a powerful reducing action if long applied, and is free from the tendency to stain, unless, indeed, it be applied to a very imperfectly washed print containing unremoved hyposulphites. But it has the disadvantage of converting a portion of tlie image into chloride of silver — a portion at least of which must remain in the print unless removed by a second solution. However, by adding to the acid solution sufficient chloride of sodium to saturate it, it is converted into a one-solution reducer, the solvent action of the chloride of sodium sufficing to hold the small quantity of chloride of silver formed in solution, and to allow of its removal by simple washing. The solution as I have employed it is made as follows : — A hot saturated solution of common salt is made, and when cold, to each ounce of it two ounces of alum and half an ounce of hydrochloric acid are added. This solution acts slowly, but with great regularity, and its action is complete just when the print appears of the right depth. All that remains then is to wash tho- roughly to remove the soluble salts and free acid. Another reducing solution which is to be preferred in some respects to that of alum and hydrochloric acid is one composed of a soluble hypochlorite. This will bo preferred by many, because it acts also as a hypo eliminator, perhaps the safest there is, since it converts any hyposulphites remainingintheprints into the least injurious compounds. Its chief fault as an eliminator consists in its reducing action on the image, but this ceases to be a fault when it is the effect sought. The hypochlorite may be used in the form of eau de Javelle or " Labarraque's Solution," formulae for the making of which will be found in the pages of the Almanac, or it may be purchased in the form known as " Ozone Bleach ; " these all consist of solutions of hypochlorite of sodium or potassium, not pure, it is true, but suffi- ciently so for the purpose in view, or the pure hypochlorite may be employed, though at a much higher cost. The action of the hypochlorite upon the image is to convert it into chloride of silver— not hvpochlorite — oxygen being at the same time disengaged ; any hyposulphites remaining in the print from the fixing are, at the same time, converted into sulphates, and, in the case of the silver salt, eventually into chloride. Here, again, the necessity exists for some means of removing the chloride of silver thus formed ; but this is easily effected, in the manner already described, by the addition of salt. In fact, in making up the reducing solution, it is only needful to substitute saturated solution of salt for plain water, adding sufficient of the hypochlorite to confer the desired energy. The above are undoubtedly the best reducing solutions I have met with in the course of some years' experience, but it may happen that such a solution has to be made up in an emergency, when possibly the materials given above are not available. Nitric acid, however, finds a place, or ought to do, in every photographic laboratory ; take a couple of drachms, say, of strong nitric acid, and dissolve in it a salt- spoonful of salt, or, at least, let the strong acid take up as much as it will, and then dilute it with water to the requisite strength. This forms a complex solution, in which, in all probability, nitro-hvdro- chloric acid exists ; at any rate, it converts the image into chloride in a far more perfect manner than hydrochloric acid, and is much to be preferred. It must be followed, however, by a fixing solution; but for this purpose I should strongly object to hypo, on account of the washing required after it. Considering the small trace of chloride of silver to be removed, a strong solution of salt, or, better still, of sulphite of soda, will be quite strong enough, and the products of decomposition, as well as the salts themselves, are far more easily removed than in the case of hypo. W. Lindsay. THE PICTORIAL MODIFICATION OF PHOTOGRAPHIC PERSPECTIVE. [Society of Arts.] EvEB since I invented my system of reflected electric light, which I had the privilege of exhibiting in this room many years ago, and put asid« for a time my palette to join the ranks of the photographic profession, I have been made to realise as acutely as any one the limitations, im- possibilities, and shortcomings of pliotography. Not only have I felt them limiting my ambition while trying unconventional posing, but because of them it has often been painfully irksome to have to ex- plain the restriction of my powers to a class of sitters whom I may fairly describe as the non-photographic tj'pe. These sitters — and most of them, I must confess, are of the fairer sex — are prone to lament that their hands (which they always try to hide), to say nothing of their heads, waists, and so on, come out much too large. Others, again, fancy themselves much taller and slimmer than they optically, or perhaps I may say, architecturally, really are, and I have always been compelled to admit that they are right — that is to say, visually right, artistically right — and that photography in their case could not do justice to one's visual impression. The invention which it is my privilege to submit to your notice this evening is, therefore, the outcome of necessity, and meets a great want, which all leading men in the profession, and many amateurs, have long and keenly felt. The " Truth " of Puotoghaphy. On few subjects, I venture to submit, has there been of late so much discussion, so much debate, and so great a confusion of ideas as on that of the question of the truth of photography, and the value of its services to art, which latter have been most generously and freely admitted by the greatest masters of the brush amongst us. But, now that we are attemptingtocorrect figure, portrait, and landscape photo- graphy, I think the time has arrived when we may usefully attempt to analyse it, and appraise it at its actual value ; the more especiallj' as I am convinced, from careful observation of the work of some of the best draughtsmen and painters of to-day, that the close study of photography is ruining their judgment, and vitiating their apprecia- tion of the beautiful. Eloquent proofs of the baneful effects of the new creed, that photography cannot lie, appeal to us on every hand. Take up, for instance, the current number of the Century Magazine ; here we find a draughtsman of the first rank permitting himself to draw horses in action as no other man has ever drawn them, as, I venture to add, no human eye has ever seen them. Obviously he has studied instantaneous photography, and honestly believes that he is taking a fearless and conscientious new departure in pictorial art in the cause of truth, oblivious of the fact that the camera registers a section of an action immeasurably more minute than the eye of a man can chronicle and convey to the brain, and therefore he depicts what he has never seen — depicts what is, to all practical purposes, an untruth ; a state of affairs of which no human cognisance has, or can be naturally taken. Similarly, we see portraits nowadays painted under a like influence ; time was, about half a century ago, when artists, obeying the behests of fashion, painted heads, hands, and feet absurdly small. Photography, no doubt, is responsible for the reign- ing reaction. The tendency of town dwellers — the professional class, artisan?, ' tradesmen, &c. — who get little exercise for their whole bodies, and use their heads and hands only in the struggle to earn a living, is to beget a large-headed, small-bodied race ; while those who, from early youth, get plenty of exercise — the privileged classes, the aristocracy, the agricultural labourers, and even the miners — are noted for their more symmetrical or classic proportions, and their well-poised, small heads. We see at the Royal Academy, the .Salon, and elsewhere, portraits disfigured by enormous heads, hands, and feet, looking for all the world as though their outlines had been traced from an enlarged photograph originally taken with a short-focus lens. We see figure pieces intended to carry us back to classic times, which would be delightful and perfect but for something which takes away their individuality, which makes them too familiar, almost vulgar : what is this something ? It is, that we instinctively recognise in the figures the type of the modern town-bred model, or of the sedentary professional race, perhaps members of the artist's own family .. It is not, however. M«y r,, 1893] THE BRITISH JOURNAL OF PHOTOGRAPHY. 277 given to every painter of classic subjects to so appreciate and adoro that perfect harmony of a classic form as to bo able to be true to, and resist the deterioration of, his ideal through the constant contem- plation of his modi'ls and the baneful inUuence of optically distorted photography. Optical Truth and Visual Tbuth. Science protests that photography cannot lie. Well, optically, it cannot. I have been tryinf; to put my argument into a nutshell. I may not have succeeded, but here it is for -what it is worth — " Optical truth is not visual truth." This may seem very much like a parndox, but the dictionaries are so singularly unaidful to me in my dilemma, that, for the sake of argument, we must let it stand for the present. The force of the statement is, however, one which the future must speedily recognise. Optical truth, then, as far as photography is concerned, is the result of a mere mechanical impression on a plate, which is some- times more wonderful and beautiful than anything tlie human hand could fashion ; but which, on the other hand, is sometimes so brutal in its fidelity, and microscopically vulgar, as to give one a very dis- agreeable surprise. Msual truth is a vorj' subtle quality. Its appreciation depends on the observer's artistic sense and powers of comparison. I would go as far as to claim it as an hereditary quality which different people possess in different degrees. There is a great distinction between it and optical truth, or the truth of the camera. The camera focusses every spot at the same instant, without favour or prejudice, uninfluenced by natural selec- tion. The impression on the brain, on the contrary, is affected by all these things. The eye focusses only one portion of an object at a time, and, whilst the rest of such an object is within the diffused vision, the impression on the brain depends on the temperament and the more or less artistic environment of the observer, the brain instinctively and unconsciously recognises the quality of distance. In portraiture wo have to please the family, the relatives, and the friends of the subjects — those, in short, who are most familiar with their appearance ; and, in their case, the visual truth is the outcome of loving and friendly contemplation. The first essential for a successful portrait-painter is that he should be sympathetic, possess a great deal of the milk of human kindness, and love his fellow-man. These are the gifts that will enable him to approach his sitter in the family spirit. When he paints a portrait, say, of a sweet old mother, he unconsciously tones down and modifies the optical truth, and, guided by the visual truth, he accentuates the air of distinction and spiritual dignity which his own refinement enables him to see and appreciate. But the photograj'her, though he be a born artist, and ever so appreciativi; of these qu.alities in his sitter, is cribbed, cabined, and confined within certain limitations and poses. It is almost use- less for him to study the work of the great portrait-painters, for the moment he copies an unconventional pose, say, with hand or foot extended towards the camera, he produces a libel, and I defy any one to judge of the actual size in proportion to the body of the extremi- ties of a sitter when thus brought forward in a photograph. It has been advanced by some that this distortion can be overcome by a long-focus lens at a long distance ; but, although it does partially reduce it, the conditions are unnatural, and the portrait loses that subtle yet powerful effect which makes one see the sitter in one's very presence, what one might call a " speaking-likeness " effect, to obtain which it is essential the point of sight, whether optical or visual, should have been within a conversational distance. A long distance immediately suggests a theatrical effect, unsuitable for the portraiture of private people. Whether this view is correct, or would only occur to one having the knowledge and practice of these distances or points of sight, is perhaps open to discussion. I will now give you a number of pictorial illustrations by magic lantern, showing the difference between optical and visual truth, pro- duced without changing the lens in front of the camera or the distance from the sitter. I will also show you the wonderful possibilities of this new power by a single humorous illustration, using a photograph of ^Ir. Marshall P. Wilder, that quaint American humorist, for my subject. 1 will also take a portrait by my light in an unconventional pose, and correct before you its inevitable distortion, and after- wards give you, as well as I can, a scientific explanation of my invention. The Problems to bb Solved. Before I had brought my invention to its present state of adapt- ability, I found I had to solve five problems :— 1. To reduce locally the size of a head or hand, or other portion of a figure, and to do it symmetrically, so as not to change the character or symmetry of a head or the expression of a face ; or, in the reduc- tion of a hand or waist, to reduce, if desirable, the width only, and thus give a slender instead of diminutive effect. 2. Having solved this first problem, bow to find a way to make a number of corrections in one negative at the same time, and with such simplicitv and rapidity as na(/ April 29, 1893. SPECIFICATIONS PUBLISHED. 1892. No. "567. — "Photographic, &c., Materials." Christy. No. 9819. — "Photographic Cameras." Beck & Claeke. PATENTS COMPLETED. Improvements in Ajtaratus for Taking Instantaneous Photographic Pictures. No. 10,353. Georges Philibert Charles Maroniez, 101, Rue Faidherbe, Boulogne-sur-Mer, France. — March 4, 1893. My invention has for it.s object improvements iu apparatus for taking instan- taneous photogi'aphie pictures, the movement of the shutter and the changing of the sensitive plates or surfaces being effected by a single movement of a knob or handle. The apparatus consists of a box or camera forming a dark photographic chamber, provided with a lens adjustable by a rack and index, so that the exact position and focus can be determined beforehand. Behind and against the front of tlie camera is a shutter in the form of a disc, revolving always in the same direction. It is provided with two opposite openings, which pa.ss in turn in front of the opening of the lens, aucf it is mounted upon an axle having a toothed wheel, operated by a coiled spring, whicli can be wound up with a key when required, so as to afford a considerable number of exposures. At right angles to the diameter of the disc on which tlie openings are made, and at its circumference, two catches are arranged which serve as stops. For this purpose they act in combination with an escapement or anchor piece pivoted iu the upper part of the camera. This escapement is held back in its normal position by a sjiring, one of its teeth being down and the other up, so that the first engages with and holds one of the stops upon the disc, and prevents the latter from turning. When, by the action of a bar or pusher moving longitudinally and provided with a tappet, the escapement is turned on its centre, the tooth described is released from the disc, which makes a semi-revolution, uncovaring the lens as it does so. The other tooth of the escapement, which is now down, then stops the other stop upon the disc, but when the pressure upon the pushing bar is released it is returned to its normal position by a spring, and the escap<- ment takes its original position, the second stop upon the disc being release' 1. but being immediately caught by the other tooth of the escapement, where it is held in readiness for another exposure, and so on as often as may be desired. May 5, 1893] THE BRITISH JOURNAL OF PHOTOGRAPHY. 283 111 order to change between eacli exposure the sensitive surface, which may be either glass plates or films of any convenient size, they are contained in frames or discs of tliin metiil slightly concave to give elasticity, and having their edge turned over to hold the plate or film. These frames are arranged one Ijeliind the other in the back of the camera, and arc all pressed forward by a spring. They are supported below by two guides, allowing a slight amount of pby, and the front frame is pressed against two pieces of metal, which project very slightly above the ends of the guides, and have their projiitinj; ends r.nmdeiL In the miildle of the upper part of the camera is arranged a longitudinal bar or spindle, turning in bearings, :ind having upon its front end a toothed pinion gearing with a rack upon the pushing bar already described, so that, imme- diately after the shutter has operated, the pinion and spindle are made to make a miarter of a turn. The spindle carries two curved teeth at right angles to each other in end view, and one somewhat in adv.iuce of the other, the forward tooth, which, in its normal position, is inclined ilownward and curved to the left, serving to release the front sensitive plate and fmnie. For this purpose it is combined with a stop at the end of a Hag spring, which presses it down, and against which, in this jiosition, the top edge of the first or front frame presses. By the revolution of the spindle by means of the rack, the front tooth rises to the left, and, having made an eighth of a turn, comes against and presses up the spring and sto[), pushing the latter into a recess in the top of the camera, so that the top of the front franu- is released, and being pushed forward by the spring at the oack, and by an angular spring describeil presently, falls forward {turning upon its lower e'dge), and, g.iided by two curved guides in tlie body of the camera, falls Hat upon the bottom of the latter, where it is held by two springs in the sides. At the same time th.at the forward tooth upon the spindle lias moved up, the corresponding back tooth has moved down, and prevents the next frame from falling forward. When the pressure upon the pusher bar is removed, the spindle is brought I'lck to its original position by a spring, and the next frame is pressed forward i;id held in i>osition ready for a fresh exposure. The back tooth upon the spindle operates a wedge-shaped piece at the end of a Hat spring, which tends to force it down. This piece has a notch, into which the said back tooth engages, and raises the wedge into the recess at the top of the camera. When tlie tooth is lowered, it releases the wedge, which is forced down by its spring, its edge entering behind the frame which has just been exposed, and driving the upper edge of the latter forward so that it falls over as already described, even in case the camera is inclined somewhat backward. Inside the camera, at its right and left sides, .are two vertical springs of thin steel metal split into strips of dilferent lengths, the thickness of, say, three superposed frames being left between their successive ends, which are bent somewhat outward, so that the frames as they fall easily press them back, but are aftenvards prevented from rising from the bottom, or being displaced, even if the camera is turned in any direction. An opening in the bottom allows these exposed plates to be removed without disturbing the others. The pushing bar is provided at its end with a sjiring cam, which, at each operation, advances a ratchet wlieel one tooth, the wheel having a number of teeth corres]ionding with that of the plates, and having an exterior index hand which can be brought back to zero by a button, and indicates auto- matically the number of plates exposed. The pusher bar itself, which actuates the entire mechanism, is of brass, having a rack cut in it to fit the toothed pinion on the spindle, and it is also provided with a pall which in its forward movement actuates the escapement. This movemeut is so arranged that the escapement is released after the first part of the stroke, during the remainder of which the teeth upon the spindle disengage a frame :is described and cause it to fall to the bottom of the camera, the two movements beirg in succession and not simultaneous. The pusher bar is operated by a cam having an exterior thumbpiece which can be woi ked without shaking the camera. By turning this thumbpiece a iiarter of a tuni, the cam is turned and forces forward the pusher bar, which * trts the escapement and the sjundle. A safety catch prevents the thumb- ■ifce from being accidentally moved. WTieu the pusher bar is brought back by its spring, the whole of the parts ike their original position ready for a fresh exposure, and all the required movements are made with great rapidity by a simple pressure upon the thumb- piece, so that a large number of exposures — say, twenty a minute — may be made without interruption. From its simplicity of construction and operation, only a simple pressure upon the thumbpiece being required, the apparatus may be safely used by ' ;rson3 inexperienced and without knowledge of photography. Imi'Bov-emests connected with Photogiuphio Cameras. No. 8067. Samuel White Rouch, 180, Strand, London.— J/areA 18, 1893. IM8TEAD of the narrow piece made removable, which was detachable from the baseboard which folded over so as to protect the focussing glass, as described '•-> my patent (Xo. 1418, April 11, 1878), I now make this removable narrow i.-ce much broader, so as to extend nearly from side to side of the baseboard, :id have it attached thereto, so as not to be removable, but to slide in and out 1. ithin defined limits by means of a nek and pinion. The front of the camera, tiy which the lens is carried, may, as in my former arrangement, be attached ■ '■ this travelling and adjustina piece at either of its ends, so as to provide for •Jier a short or long extension by the bellows body of the camera to provide : the including of wide or narrow angles of view ; and, whereas the former irrow adjusUble travelling board had one rack only, my improved one - fitted with two— one at each side — thus ensuring steadiness and parallelism : motion. Atttiched to the back of the camera is a repeating back adjustment 'ready known in some othei- cameras), by which, instead of one single ■turc the full dimensions of the camera, two of smnllor size may be taken le by side. To provide for the increased raising and lowering of the lens in the camera, the front slides in grooves at each side, and at its liottom ingresii of light to the camera is prevented by a folding gusset arrangement of leather or similar material attached respectively to the solid front of the camera and the movable lens-carrying front, liy which arrangement light w totally excluded, even when the movable front is considerably raised. Tliia camera may be used for the proparatus. Tlie stop or diaphragm of tlie lens is moved as follows :— I attach a roller to the shaft carrying the wheel and lever handle ; to this roller one end of a cord or chain is attached, the other end being secured to the knob or projection from the stop, this stop or diaphragm being preferably that known as the ins. A spiral or other spring fixed between the side of the camera and the knob of the stop serves to bring it back to any required position. An adjustable pin or screw permits of any degree of adjustment of size of aperture. For use with my invention I prefer that form of exposing shutter known as the roller blind, fitted as clo.se as possible to the sensitive plate or film. The claims are :— That oue movement of the lever handle in one direction raises the mirror .and the doors of the focussing chamber at the same time, opening the stop of the lens to its full aperture, thus enabling an accurate focus to be obtained by means of the usual rack and pinion attached to the lens or camera, and the reversal of the handle lowers the mirror, closes the doors of the focussing chamber, and returns the stop of the lens to any prearranged position. Improvements in Photographic Camera Shutters. No. 9820. Conuad Beck, 68 Cornhill, London, B.C., and Joseph Thacheb Clarke, Boston, Massachusetts, United States of America, at present re- siding at 3, College-road, Harrow, Middlesex.- jtffwcA 25, 1893. Our invention relates to photographic shutters of the type described in Clarke's Specification, No. 20,852, of 1890, in which the movable plate or shutter, revolving in one direction only, is of a circular shape, with a single exposure aperture, the size of this aperture being increased or diminished by a secondary or auxiliary semicircular fan or stop attached to the face of the main shutter disc in sucli wise as to obscure a greater or less portion of the aperture thereof With an auxiliary stop of this nature, the exposure aperture in the shutter disc may be varied from the narrowest radial slit to a concentric zone extending to a length of 180 degrees. In shutters of this type, the exposure aperture, whether narrow or wide, lias hitherto been so arranged as to pass immediately in front of the lens on the shutter being sot in action : the auxiliary stop, i.e., the semicircular obscuring plate attached to the main sliutter being moved, in tlie act of increasing the aperture, in a direction contrary to that in which the shutter disc is revolved. It lias been found in practice that this arrangement does not give the greatest possible latitude of exposure, inasmuch as the shutter disc, when released, revolves with a gradually accelerating motion. Thus the narrowest available slit, being immediately adjacent to the lens aperture, was passed in front of the lens at a slower speed than was any portion of the zone situated at greater distance from the lens. It is obvious that the result of this acceleration has been to decrease the variability and range of the effective photographic ex- posure, which was thus not directly proportionate to the aperture displayed in the shutter disc by pushing aside the auxiliary stop from the zone. Our present invention not only obviates this disadvantage, but profits by that very acceleration in the rate of travel which has been observed in the movement of the circular shutter disc. We ol)tain this advantage by so con- structing the auxiliary semicircular obscuring plate that it is moved, in the act of increasing the aperture, in the same direction as that in which the shutter disc revolves. According to this arrangement the narrowest available slit is situated not immediately adjoining the lens aperture, but at a distance of one hundred and eighty degrees therefrom. In other words, all that por- tion of the aperture zone which is obscured by the auxiliary stop has to be passed across the lens before any light is admitted. Tlius the largest possible aperture is passed across the lens at the slowest average speed, whilst the n.arrowest aperture is passed across the lens at the most rapid speed. By this method of constructing the obscuring plate that acceleration in the motion of the shutter disc, which has hitherto been a drawback, is rendered actually advantageous. . , , . . The ch.ange in the operation of the obscuring plate involved in our present invention naturally leads to certain alterations in the details of the shutter. As no time exposure is possible without the introduction of an entirely inde- pendent detent, the secondary or retaining click, with its lifting apparatus, de.scribed in the before-mentioned Specification, No. 20,852, of 1890, is omitted. It has, furthermore, been found economical and otherwise advant.ageous to re- place the screw cap attachment, which was at first employed for the purpose of holding the obscuring plate against the shutter disc by a light spring clip of thin metal affixed to and revolving with a shutter disc, and capable of exercis- ing sufficient pressure upon the two plates to prevent their relative position from being unintentionally altered. A New Magazine Camera. No. 6243. Samuel Dickinson Williams, Moorlinch House, Clytha Park, Newport, Monmouthshire.— .Uo?-c/t 28, 1893. According to my present invention I form my camera with a double bottom, that is to say, with a platform stretching about half the length of the camera, and raised parallel above the Hoor thereof so as to leave a spice between sufficient to enable a sensitised film or sheet to pass along. The films or sheets or other sensitised surfaces, hereinafter referred to for brevity as films, are packed and rest with their edges downwarcnclcnt working and inalie the continuous travel of the system of pulleys and cross careiers, or the general action of the mechanism iu dcMcribeil ; set the shutter and release it as fast as the films are brought into position. I arrange a driving band on a driving wheel or pulley on the side of the camera gearing into the system of pulleys ami cross carriers, or I drive the general movement from the sci-ew shaft by suitable gearing, from which it will be seen that the continuous rotary motion of the driving handle and the general arrangement and raechanLsm as described will enable the films to be exposed in rapid succession until the charge of films or sheets in the camera be exhausted. Improvements is Photooraphio Cameras. No. 10 167. John Fk.vthbrstonkhaugh Parsons, Siddington House, ' Kingsdown-parade, Bristol.— J/«rcA 25, 1893. This invention, which relates to photographic cameras— more particularly hand cameras— has for its objects to obviate certain disadvantages appertaining to cameras as hitherto constructed and fitted. According to this invention, in its relation to the use of films, the latter, instead of being, as heretofore, in a continuous roll, are separate, and each film is carried on the face of a mount of canlboard, paper, or other suitable substance, to which it is attached. The mounts carrying the films are piled on end, and at the base they are separately hinged to a common foundation of tissue paper or other snitaWe pliable material. The pack of mounts and adhering films thus .arranged in book form is placed on a shelf in the camera, and a spiral or other suitable spring is brought to bear on the back of the pack, wliich thereby tends to advance towards the lens, but is restrained by a stop situated at each side of the camera. Wlien an exposure lias been m.ade, the said stops are operated so as to release the foremost film of the psvck and to retain the rest. The camera is then tilted forward, and the released film descends on its hinge, face downwards, until it is arrested by the spring of an indicator. The operator then turns a rod by which a vane, arm, or frame, is brouglit to bear on the back of the mount and forces it past the indicator, by wliicli latter the descent of tlie iilm is indicated to the operator. Tlie film descends to the lloor of the camera and is detached at the hinge from the rest of the pack, which, under the influence of the spring Ijehind it, has advanced to the extent of the thickness of a mount. After exposure of the now leading film of the pack, the actions above described are repeated, and so on for each until the whole pack has been exposed. When, at ;iny time, it is desired to take out a film or films from the camera, a slide in the latter is opened, and the film or films removed without waste of film, such as is entailed with the use of rolled films, and without disturbing the unexposed films. Acconliug to this invention, in its relation to the use of sensitised glass plates, the latter are arranged in a pack of frames or cases placed on end and hiiig.-d at the base, which is inclined, by webs of paper, parchment, or other suitable material, to a common foundation. The pack of frames or cases oanying the plates is placed with the inclined base downwards on a corre- spondingly inclined part of a carrier in the camera, the longest frame or case being in front, that is, facing the lens. To the carrier is attached one end of a spring consUmtly tending to draw the carrier towards tlie lens. A rod, furnished with suitjible restraining stops, prevents, at the will of the operator, any forward motion of the carrier. The stops are so .arranged that, when one plate has been exposed, and is allowed to fall on its hinge, the plate im- mediately liehind it is prevented from descending with it. As each plate is used and lowered, a holder, connected to a spring, acts in conjunction with the stop rod, and holds the plate on the bottom of the camera, where they lie, lace downwiirds, one exactly over the other, a result due to the inclined base of the pack and the inclined part of the carrier, which is advanced to the extent of a plateholding frame or case at each change of plates. The changing is effected by one mann.al motion only. This invention consists, further, in an improved shutter for the lens. The shutter is composed of two sliding plates so shaped as to present, when moved apart, a di.amond-shaped aperture. The plates, which .ire contained between guides, are normally kept closed by a spring of indiarubber or metal. To open the shutter, pressure is applied to the outer ends of two hinged levers, which, on being pressed inwards at the said outer ends, and consequently forced apart at the inner ends, cause the plates to recede from one another and from before the lens. Witli this form of shutter no setting is necessiiry, and iustantaneous and time exposures are made without altering the shutter or ihe motion by which exposure is made. Moreover, light is first admitted at the centre of the lens, which is also the last point of closure. .Mb. Edward A. Kick has sent us a sample of his " Reliance" retouching medium, and which, after giving it a trial, we find to quite bear out the name that has been given to it, for it gives a responsive surface to the touch of the pencil, whether applied with a hard or a delicate pressure. It dries quickly, and is ready for use within two minutes after application. jVn Automatic Rocker, invented by Messrs. Pittar & Thompson, is ingenious. Two small pans are balanced on a pivot, in such a way that, when one is filled by the stream of water flowing in, the weight causes it to oscillate, and the water to flow out, the other pan now taking its place. This reciprocal action imjarts movement to a balanced false bottom in a tray adjoining, and on which is laid the neg.ative to be washed. Old photographers, who were ac- iiuainted with the washing machine of Cornelius Hanbury, will recall the similarity of the means for effecting the oscillation, but this one differs in certain respects from the one of former times. mtttinosi of IboctettejEt. MEETINGS OF SOCIETIES FOR NEXT WEEK. DKt« of U««Ung. Mays. :: I: „ 8. .. 8. :: I: :: I. „ 9. >. ». ., 9. „ ». .. 10. „ 10. „ 10. .. 10. „ 10. „ 10. „ 11. ,. 11. „ 11. ., 11. » 11. .. 11 » 11. >. u. „ 12. „ 12. „ 12. ., 12. >. 12, „ 12. „ 12. „ 12. ,. 13, Huie ol Societ;. OamaraOlob Darliucrtou. Dundee Amateur NorfoUc anil Norwich, PlM« ol MMting. Charing Oron-road, W.O. Trevelyau Hotel, Dai-liueioa. Amo, Htadio, Nuthergftta, DnndM Bell Hotel. Norwich. North Middlesex i Jubilee House, HorMey-road, 5. UichmoDd , BirmiiiKham Photo. Societj . Derby Great Britain Hackney Hanohester Amateur Paisley Rochester Stockton Leicester and Ijeicestershiro . LeytoDbtone .• Hunster Photographio Olnb Sonthport Stockport Birkenhead Photo. Asso Camera Club Cheltenham Qloesop Dale , Hnll London and Prorinoial North Kent Oldham Bristol and West of England , Cardiff Croydon Microscopical -.. Halifax Camera Club Holbom Ireland Maidstone West London Hull Oreybonnd Hotel. Club Room, Colonnade HoteL Smith's Restaurant, Victoria-tt. SO, Great RaBasll.st. Bloonuboiy. 206, Hare-atreet, Haoknsj. Lecture Hall, Atbensom. 9, Gauze-street, Pauler. Mathematical School, Rochester. Mason's Court, Hi^rh-street. Mayor's Piirlour, Olrl Town Hall. The Assem)>ly llooms. High-road. School of Art, Nelson-pUce, Cork. Anderton's Hotel,Fleet-iitreet,l£.C. The Studio, 15, Cambridge-arcade. Meohanlcs' Institute, Stockport. Y.M.C.A.,Gr»nKe-rd.. Birkenhead. Charing Cross-road, W.C. 71, Prospect-street, Hull. Champion Hotel, 15, Alder>gato-«t Gravesend. The Lyceum , Union-st., Oldham. Rooms, 28, Berkeley-sq., Bristol. Public Hall,G6orge-8treet, Croydon- Rooms, 15, Dawson-street, Dnblhi. "The Palace," Maidstone. Chiswick School of Art. Chiawick. 71, Prospect-street, Hull. LONDON AND PROVINCIAL PHOTOGRAPHIC ASSOCI.ATION. April 28, — Mr. J. J. Briginshaw in the chair. The Influence ok the Haxd Camera. Mr. W. D. Wblford read a paper on this subject [see page 279.1 Mr. R. P. Drage thought that, although some hand-camera workers might secure nine or ten pictures out of twelve exposures, they were only a drop in the ocean, and that as regards the wasting of plates the hand-camera men had the pull. Mr. W. E. Dbbenham, as to Mr. Welford's claim that the hand camera tended to quicken a man's perception and readines.* for carrying out a train of movement in a rapid manner, tliought the use of the hand camera might in that respect be compared to certain games of skill. As to tlie speed of plates having been quickened by the demand for rapid plates for the hand camera he (Mr. Debenham) thought that a mistake. He had used as rapid plates (of his own make) ten or twelve years ago as were obtainable commercially now. Mr. G. Austin thought that the hand camera as a companion on walking tours passed the time very pleasantly. Mr. J. S. Teai'E corroborated Mr. Welford's remarks as to the necessity of speedy action when photographing in crowds of people. Tlie hand camera had certainly increased one's power in that direction. He did not agree with Mr. Welford in his reference to the articles on .art, which appeared in the jounials, as " padding." They were of great use at times and no check should be used against their appearance. Photographers had learned a great deal from them. Mr. T. BOLAS thought such articles useful from the point of view of awakening thought, even though the articles might themselves be valueless. Mr. Simpson, of New York (a visitor), said he had been travelling for three years and had carried a hand camera all the time and wished to say something in its defence as it was abused on both sides of the Atlantic. He used a whole plate camera for landscape work but if one travelled with any baggage it was too cumbersome. He had taken 1200 negatives with the hand camera in the course of his travels, and showed lantern slides from them made on Carbutt's lanteni plates which were three years old. Mr. J. H. Avery thought that, if photography was to take up a position as a fine art, it would not be due to the liaud camera. -Mr. R. Child Bayley asked, if Mr. Welford regarded articles on art as padding, why such a large proportion of the articles in his paper were ou artistic subjects ! Mr. P. EVERITT said that if any camera sinned in giving drunken architecture it was the hand camera. As to the speed of plates being influenced by the hand camera, he thought the .assertiou was altogether wrong. He (Mr. Eventt) did not believe it for one moment. It was due to competition on the part ot platemakers to supply the public with what they wanted, and to claim it as due to the hand camera was a piece of cheek. Professional photographers required quick plates and the increase of speed was as much due to the use of large plates as small. Mr. Welford's sneer at articles on art cut against the paper he had just read. Mr. J. Nesbit detailed some recent experiences with a fixed-focus hand camera which had resulted in failures. Mr. S. J. Beckett said the hand camera was an advantage when travelling, and showed results he obtained with one which he could not have got with a st.and camera, or even at all. After further observations Mr. Welford replied : Too much had been made 280 THE BRITISH JOURNAL OF PHOTOGRAPH j:. [May 6, 1893 of the waste of plates in the hand camera ; there were just as many failures with the ordinary camera. Having instanced the utility of the hand camera in street work from his own experience, he said most of the arguments used against hand cameras were the usual arguments of non-workers. A vote of thanks to Mr. Welford closed the proceedmgs. Hackney PhotograpMc Society.— April 25, Mr. E. Beckett in the chair. A print of uneven colour was shown and a question was asked as to the reason. A reply was given that the toning hath was out of condition. Mr. Roberts 5.sked if after developing in pyro a plate can be put into amidol for further detail. Mr. Dresser said it was like jumping from the frying-pan into the fire, and was not altogether advisable. Mr. Puttock asked how to remove pyro stains from the hands. Jlr. Beckett said one way was to wash in 1 : 4 hydro- chloric acid. The Hon. Secretary asked Mr. Dresser how he removed amidol stains from the hands. Mr. Dresser said they cannot be removed, must wear off, but washing in the dark was a good plan as the light caused an action on amidol. Mr. Hudson had been experimenting with developers for snap-shot work and gave an excellent formula, an admixture of eikonogen and quinol with caustic potash. Mr. Deesser then gave The After-work of the Hand Camera. Although he treated very largely upon this subject, he was drawn into other questions upon the hand camera, for which he is so well known, and gave among other details the following : — The chief point was a good lens and shutter and he advised a shutter working between the lenses, roller slide or films, objected to magazine form owing to the tendency to stick. A good eikonogen formula for sna))-shots is : — Eikonogen, 1 ounce ; sulphite soda, 5 ounces ; carbonate of potash, 1 ounce ; caustic soda, IJ ounces ; water, 30 ounces ; and for use take 1 ounce of solution and 1 of water. For fuller exposures he would add bromide and redevelop by adding a little hydroquinoue. He had been experimenting with metol, but did not find it quite so good as amidol for short exposures. His amidol formula was :— I. Amidol, 1 ounce ; raetabisulphite potash, 1 ounce ; water, 10 ounces. II. Carbonate of potash, 1 ounce in 5 ounces of water. III. 10 per cent, solution bromide potassium. For bromide work he would use 1 ounce of I. and II. and 1 ounce water, adding bromide for full exposures. He used in enlarging the incandescent light, but care was necessary ; one light was placed behind the other, as better illumination was given. Mr. A. Barker asked whether it was necessary to have a rising front and swing back to a hand camera. Mr. Dresser was of opinion a rising front only was necess.ary. In answer to other questions Mr, Dresser preferred a four and a quarter or a five inch lens, lie would develop with amidol until he got detail, and then wash and iinish with hydroquinone. Birmingham Photographic Society. — April 25, Mr. W. Jones in the chair. — An extremely fine set of slides by Mr. Hendren, a member of the Society, were shown ou the screen. They comjirised beautifully selected landscape and architectural bits, and were instances of most careful and successful composi- tion. Mr. Heudri:n gave most interesting descriptions of the places and styles oi architecture ; he also instanced the different results of various methods of development by sometimes showing two slides from the same negative. This was of gi'e.at interest to members. A plucky slide of a warm brown tone was, in most instances, preferred by the lecturer. Brighton Natural History and Philosophical Society (Photographic Section). — April ".Jl, Adjourned meeting. — The new rules regulating com- petitions in the Society were adopted. The subjects also for the competitions being arranged for the ensuing year. Dr. W. Harrison owing to pressure of engagements was compelled to resign the office of Hon. Secretary. The following gentlemen were elected as officers and committee for the year : — Chairman : Mr. J. P. Slingsby Roberts. — Committee : Messrs. D. E. Caush, W. Harrison, C. Job, W. W. Mitchell, H. V. Shaw, C. B. Stoner, and A. H. Webling. — Hon. Secrelanj : Mr. G. Foxall. Halifax Camera Club. — April 25. — Mr. A. Stewart gave a interesting paper on the subject of Lenses. In the course of his remarks Mr. Stewart said that without the use of a lens, but simply by means of a pinhole, an inverted image is formed on the focussing screen by the rays coming in a direct line through the pinhole from the object. In this case there is no focus, everything being in focus at whatever distance. The use of a lens is to utilise other thaii straight rays, and, according to its focus to regulate the angle of view included and the size of the image, as well as to give greater sharpness. When a lens is used, objects at difi'ereut distances from the lens are not brought to a focus at the same point ; and. in order to overcome this, stops are used, which tend to equalise the focus. The focus of a lens depends on its curvature ; the greater the curvature, the shorter the focus. The rapidity of a lens is influenced by the size of stop used, and also by the number of refiecting surfaces in the lens. A short- focus lens gives more depth of focus than one of longer focus. Objects at a greater distance require less exposure owing to the fact that more rays of light come from distant objects. Mr. Stewart also spoke of the faults of lenses, and also of the special uses of the difi'ereut sorts of lenses. Xlverpool Amateur Photographic Association. — April 27, Mr. J. Sirett Brown in the chair.— Messrs. H. Jennings, Stanley, Rimmer, James Wilson, and David Robinson were elected members of the Association. Mr. J. T. Norman-Thomas reporte inches focus, and these are mounted in a tube of 23 inches long. The diameter of both lenses is I/tt inches." What more information is wanted ? The only thing lacking is the said "externals," or shapes of the lenses. The Phrenology of lenses is not the Science of optics. The telephoto- graphic lens was founded upon the latter, and its theory is fully explained in my paper read before the Society of Arts on March 1, and still further at the recent Camera Club Conference. In the latter I treated, as being simpler, a fixed system, such as Mr. Parvin claims to have " invented," showing, for the first time, the rationale of how, with a comparatively weak negative posterior lens, a fixed system can have a short " back focus," with the advantage of a considerably longer " equivalent lens." In Mr. Parvin's selection, and taking the separation at 2| inches, as quoted, the lens must give an image equal in size to that of a lens of 18-3 inches focus, but would only have a back focus of 10-9 inches ; if there be no diaphragm, it would work at full aperture at an intensity ot/-16-7. Again, if the lens be reversed, the back fooua would be 26'4 inches, but still the same equivalent focus of 18-3 inches. Mr. Parvin has adopted the principle I first introduced into photo- graphic lens construction, but in a much more limited degree, and, more- over, without the advantage of varying the amount of magnification and covering power. The question is, whether the amount of magnification given in his case is worth a special construction. — I am, yours, &c., 25, Newman-street, IF., May 1, 1893. Thomas B. Dallmeyer. " THE PHOTO COERECTOE." To the Editor. Sir, — It appears to me that Mr. Van der Weyde's new method of modify- ing or " correcting " the ugly and inartistic proportions of things as they often appear in photographs has scarcely been received with that enthu- siasm which it deserves, considering that it presents us with an additional means of " bending," so to speak, photography to our will, and thus removes one of the great disabilities under which we have hitherto laboured. If by using a lens of sufliciently long focus, or by taking a station point distant enough from the picture plane, we obtain what is called " wide-angled " perspective, and this gives us a picture free from those apparent disproportions which we meet with in pictures taken under opposite eonditions,iweIl and good. In such a case the " corrector " need not be employed to correct the perspective, but it has another use, the value of which seems to me, as I mentally cling to the idealistic in art ; inestimable. In the discussion which followed Van der Weyde's demonstration of his invention at the Camera Club Conference he made the weak and apologetic admission that there was money in it, as, by altering the proportions of any jiart of the human body, we can flatter our sitters, and thus secure additional custom and remuneration. This is true, but is immensely overshadowed by the much more dignified and noble consideration, that, by thus being enabled to adapt the proportions May a, 189S] THE BRITISH JOURNAL OF PHOTOGRAPHY. 287- of our moders figure to an ideal standard, we become possessed of one of the powers moat prized and mo3t exercised by all the great artists of antiquity. — I am, yonrs, Ac. Frank Wilcockson. 20 Orde Ilall-ttreel, Lamb's Comluit-itreet, fV.C, April 29, 1893. AMIDOL. To the EniTOB. Sir,— I have been away from home, and only just read the inquiry of " Cosmos." The report of my lecture was very condensed ; the actual words I used were as nearly as possible as follows : — " For photo-uiechanieal and lantern plates I was able, when using amidol, to reduce the exposure to about one-tliird the time required for the very restrained pjTO developers recommended by the makers of the plates. No doubt this was principally due to the very small quantity of bromide necessary to be used with amidol." I further said I had not tried amidol for general work, so would not express any opinion of its capabilities for other than copying and lantern slides. " Cosmos " asks what proof I can give for my assertion. All my ex- posures were made by the aid of a Watkins actinometcr. The actinic value of the light and the aperture of lens become very simple matters, and I have only to estimate and record in my note-book the subject-number. I find this plan a very simple and accurate one, as I can, without any difficulty, in any light, give to another plate a corresponding greater or less exposure, as I desire, and only by varying the subject-number. I have now developed about five dozen plates with pyro and the same number with amidol, on one series of similar drawings, and I have found the subject-numbers for amidol are about one-third of the corresponding ones for pyro. Notwithstanding this, I find the time required to develop with amidol is also much shorter than with pyro. — I am, yours, &c, 2, Craven-terrace, Ealing, May 2, 1893. H. W. Peal. AET IN PHOTOGEAPHY. To the Editor. SiK,— Referring to your note signed " F. B.," page 269, 1 should have thought that you would have long ago discarded the idea of mixing oil with water. Art in photography is about as vexatious as amateurs and professionals. The first one (artist) will not admit in his exclusiveness that any art is at all possible without him, and the second one (amateur) that any improvement is possible without liim also. The only difference is that the artist is educated to the art, while the amateur is born so ; that is, at least, the reasons given to the lower class of mortals that do not understand what they so well try to impress upon the few or many un- initiated. From all the articles on art in photography as against art in paiiiting that have been published I have gleaned the following :— An artist, however poor in art he may be, will never turn out anything but there will and must be in it some artistical merit. Bad design, bad colours, bad posing, bad everything, yet artistic. Now, a photographer, however well chosen the subject, well lighted and well finished the result, is never artistic— at least, from an educated artist's views. Why not let this matter rest a while now ? I, for one, would rather (uneducated as I am) have a fine photograph than a poor painting. I may be wrong, but I am pretty sure that, however educated an artist may be, he mil not average in taking photographs more than one real fine view out of a dozen, and ditto the artistic photographer. Of course, they may not admit this readily ; but, nevertheless, they will sliow you always very few of the results of their work, carefully omitting mistakes and failm-es. It is human nature only, after all. They all do it. I have tried several makes of films lately, and, as you object generally to giving names, I do not think that the results obtained would be very interesting to your readers. With one English firm I have always very fine results, while with the others I have uneven ones, such as frilling, no intensity, and disagreeable lifting of the gelatine whUe printing. I have also tried lately some American films, which have a rough or ground back to them. Having given what I think a correct exposure, I found the picture come up pretty quick ; but the film (developed with pyro) was fearfully stained yellow, and the back of it same way, so that it takes a whole day in full sun, and with this fair weather, to get one print. I tt wish you could tell me how to get rid of this yellow stain, if possible. 41, T^?*^ ^?" ^""^ """^ *^° '° regard to the Exhibition at Chicago, and the failure I met witli in regard to obtaining an answer from the head of ► the photographing department. Do you know of any one that has met J with better success ? and if so, please let me know how he managed it, so » 1 may do the same.— I am, yours, itti'rly incapable of receiving a developable impression with any exposure. To place the matter beyond all question, a portion of the Lielatine film wa.s carefully and com])leteIy removed from a plate liy scraping, followed by warm water. The whole plate was then coated with tlie same unwashed emulsion, so that a portion of it presented a compoimd film of collodion and gela- tine, while the remainder consisted of collodion alone. Upon exposure and development the image upon the double film was of the same character as already described, namelj', it was partly or mainly on the gelatine, and slightly, though quite distinctly, upon the collodion. Upon the plain collodion portion of the film, on the other iiand, there was not the slightest trace of uny image, although the development was intentionally pushed to the stage of incipient fog. The result points certainly to the conclusion that it is an erroneous supposition that the films arc not in .some sort of chemical contact, but how the image on the collodion film is formed is an interesting (question that is open to argument. At least, we may drop the assumption, as, indeed, we seem to be forced by other facts to do, that the different films are infert towards one another, except in so far as they act as light-screens, absorbing a portion of the light that passes through them. It seems more reasonable to take the view, as presented by the experiments of Captain Abney some years ago, that one film does very materially affect the other iu development to such an extent, indeed, that in some instances it is found that, if a second film be coated on top of another after it had been ex- posed, on development an image will be produced upon the unexposed film. This appears to be the only explanation of the experiment we have quoted. We can readily imagine that, on proceeding to develop the compound film, the excess of bromide contained in the collodion will be absorbed by the swelling gelatine under- lying it, which will in this manner, as well as by the upper film of collodion, be powerfully restrained or retarded. Mr. W. K. Burton has shown that the effect of bromide in the developer is merely to retard develo|imeut, not to destroy the image ; hence, as we have shown that it was necessary to i;ive three or four times the exposure required by the bare gelatine film, the latter must have received a very full impression, and during develop- ment may be taken to represent a store of pent-up force capable of reacting on the practically insensitive film above it ; or it must be borne in mind that the collodion film, containing, as it does, the unremoved decomposition salts, as well as the excess of bromide useful to its due keeping, is, if not absolutely insen- sitive, at any rate sufficiently so to bear full exposure in the camera without giving the least sign of image on develop- ment, though, on re-exposure, a perfect picture can l)e produced. For all practical purposes, therefore, the collo- dion film in this case must be taken as insensitive or un- exposed. Not HO, however, in the case of a washed emulsion. When such a film is applied above the gelatine film, the exposure of the latter is not greatly increased, though the time of develop- ment is thelatter effect, being, we imagine, rather mechanically produced by the overlying collodion film than by any chemical slowing action. Under the head of mechanically produced we may include the slowing produced by the absorption of light in passing through the film, though, as a matter of fact, this is so slight as to be not worth considering. ' But the retardation of development by the collodion film is a different matter, and that that is purely mechanical may be proved by coating a plate with plain collodion instead of emulsion, in which case there is neither light arrested nor any chemical agent introduced to act upon the sensitive film. Yet the same impervious varnish suffices to render development a comparatively slow process, and also to raise some uncertainty as to whether there is really any loss of sensitiveness, or only retardation of develop- ment. The compound film produced when the washed emulsion is used gives a similar result to that from the unwashed emulsion, so far as the development of an image upon the upper film is concerned. But in this case it is with a shorter exposure, and still too short to impress the collodion emulsion itself, except perhaps in the extreme hi<;h lights, as the sky of a landscape. We have, indeed, simultaneously exposed a compound film and one of collodion emulsion alone to an open landscape with clear sky, and on development the sky was the only portion visible on the collodion plate ; in the compound film, however, the whole of the image was impressed upon the collodion portion, as was easily proved by the difference in density when a portion of the latter film was rubbed away. In this instance it would certainly be supposed that the effect of the collodion film would be to give an image showing greater contrast than that given by the gelatine plates alone, but such was not the case. Two plates were exposed side by side — or rather a plate divided into two portions — -one of which was coated with collodion emulsion, the latter receiving a slightly longer exposure than the other. On development — not for the same period — as, owing to the slowing action of the collodion, that was out of the question, but until as nearly as possible the same general density was obtained, the two images were practically identical so far as gradation was concerned, or at least it could be said that there was an entire absence of any suspicion of stronger high lights in the compound film. But — and here is the noteworthy point in the matter — when a portion of the collodion film was rubbed away, the image on the gelatine film underneatii showed decidedly less contrast than it had done previously. We do not refer to merely de- creased density owing to the removal of the upper image, but the sky had lost noticeably more density than had the other portions of the image ; indeed, the extreme high lights in the stripped portion of the image were thinner than the half- tones. The explanation of this, it seems to us, is not far to seek, and, if this action occurs between two films of collodion and gelatine, it is even more likely to occur or to come with greater force when two or more films of gelatine are in question. Bear- ing in mind what we have said about the slowing action of the collodion film upon tiic development of the underlying gelatine film, and also the well-known fact that a collodion image 293 THE BRITISH JOURNAL OF PHOTOGRAPHY. [May 12, 1893 develops with great rapidity, it might be expected that the shy of the picture on a compound film would develop at once on application of the developer, or within a very short period, and that there would then be a long wait until the solution reached the gelatine below. This, however, is not the case, for the first indications of sky did not make their appearance for fully five minutes, and the remaining portions of the picture then followed with perfect regularity. Thus we must believe not only that the upper film exercises an influence on the develop- ment of the under one, but also that the converse is the case ; otherwise, seeing that the sky of the collodion film had had sufficient exposure to produce a developable impression, tliat impression would have been produced in less time than five minutes, unless it had been held back by the gelatine film underneath it. When development did commence, it commenced from the surface — that is to say, in the collodion film. This much is evident to the eye, but is capable of easy demonstration, and has since been proved by means whicli need not here be detailed. That being the case, as tlie silver is reduced in the collodion film, bromine is given off", and either directly or in combination with the alkali of the developer, as bromide is present to act upon and restrain tlie corresponding portions of the gelatine image lying underneath and in contact with it. In other words, as the higli lights of the collodion image are developed, the bromine evolved goes to restrain the higli lights of the gelatine image and weaken them. Although the compound films with which our experiments have been made are totally different from, and, in fact, diametrically opposite in principle to the Sandell double and treble-coated films, still we think the same kind of action may be traced in both. For instance, with an ordinary short exposure, the bromine given off by the high lights of the rapid top film hold in check those of tlie second film, and contribute to the softness which is so remarkable a feature of these plates. Again, with longer exposures, it is possible to trjice the action of one film upon the other, and to explain the freedom from halation so obtained in a far more intelligent manner than by supposing it to result from mere opacity of film. Photo^rapliic Salon, 1893.— We Lave received from Mr. Alfred Maskell a notification of a proposed " Photographic Salon," for which the Dudley Gallery has been taken. Its nature will be ascertained from the following : — " An exhibition of photographic pictures, to be called the Photographic Salon, will be held at the Dudley Gallery from October 9 to November 11, 1893. Careful consideration wiU be given to all pictures entered for exhibition, and a selection of works of pictorial merit only made by a Committee. Foreign as well as English photography will be represented. The aim of the organizers of this, the first Photographic Salon, is to inaugurate a series of exhibitions (which it is hoped may be annual ones) bringing before the public the best productions of photography solely from the pictorial point of view. No awards are offered, and no charge made to exhibitors. The usual charge of Is. will be made to the public for admission. Arrangements will be made for the sale of pictures, if desired, and a commission of fifteen per cent, will be charged on sales effected." Photog-raphic Competition at the vrelsh National Eisteddfod. — -We may remind our readers that at the Eisteddfod, wliich takes place at Pontypridd in August next, photographic com- petitions will be held in the following classes: — 1. A set of not less than six or more than twelve photc^raphs illustrating the coal in- dustry from cutting to shipment. Prize, ol. 2. A set (not less than six) illustrating the industries of W^ales. Prize, 5^. 3. Six in- stantaneous photographs of a football match in its various phases. Prize, 21. 4. Landscape. Prize, 1/. o. Architectural photograph. Prize, I^. Photographs should be sent to the General Secretary, Pontypridd. The adjudicators are practical photographers, and, as the prizes are to be in money, there is every incentive for a keen and interesting competition among that large class which regards honour as not imcompatible with profit. A Constant Xii^ht for Spectrum Work.— In a paper of importance on certain absorption spectra by Dr. W^. Lapraik, he refers to the desirability of having a source of light as constant as possible, and at the same time of sufficient illuminating power. With this idea a quick-combustion petroleum lamp having a circular wick was used. This gave a very powerful light equal to forty-eight candles (British measurement). He used electric light, and also sun- light reflected from a heliostat, but did not find any material difference between the absorption spectra so obtained and those by the petroleum light. Kr. It. P. Dragre and the Iiondon and Provincial Photog'raphic Association.— Uur readers will learn with regret that Mr. R. P. Drag-e has resigned the Secretaryship of the London and Provincial Photographic Association, a position which he has filled for the past three years. The " L. & P.," as it is familiarly known, takes rank as one of the principal technical photographic Societies, its reported discussions and proceedings being, as we are aware, read with deep interest throughout the world. Mr. Drage's services to the Association have been of such a thorough-going nature, by persistent hard work and unfailing courtesy to members and visitors alike he has rendered himself so agreeable, and has contrived, week after week and month after month, to bring matters and papers of such interest for discussion before it, that he is certain to be much missed. The best wish we can e.xtend to the Association is that Mr. Drage may have a wortliy successor in the office he has so ablv filled. Carbonic-acid-free Ammonia. — The uncertainty as to the composition of any particular sample of ammonia solution re- quired for development is always a stumbling-block in the way of those who would make photographic operations as exact as possible. In estimating the strength, by ascertaining the amount of acid it will neutralise the difficulty if the presence of carbonate comes in, for it is well known that, though carbonate of ammonia preceded liquid ammonia for use in development, the latter in bromide dry plates is much more powerful than the former. Hence a simple sug- gestion by Herr J. Hertkorn, in the Chemiker Zeitung, will be of value in regard to this particular source of uncertainty. He recom- mends that some lime-water (quite free from turbidity, of course) should be added to the suspected sample of ammonia, and the mix- ture then boiled. If turbid, the presence of carbonic acid Is shown ; but if it reojains clear, or only very slightly turbid, the sample is free. Temperature Xiimit of Ziig'ht Sensitiveness.— Dr. Dewar, in a lecture on the magnetic properties of liquid oxygen, re- ferring to the extremely feeble energy displayed by the oxygen molecules at extreme low temperatures, said they seemed to be draw- ing near what might be called " the death of matter " so far as chemical action was concerned. Liquid oxygen, for Instance, had no action upon a piece of phosphorus and potassium or sodium dropped into it, and once he thought and publicly stated that at such tempera- tures all chemical action ceased. That statement he remarked in this later lecture required some qualification, because he had found that a photographic plate placed in liquid oxygen could be acted on by radiant energy, and at a temperature of 200° C. was still sensitive May 12, 18»a] THE BRITISH JOUKNAL OF PHOTOGRAPHY. Ii0.'{ to lit^ht. This fact is of considerable iraportanee as rej^ards the aetuAl result of light notion on a plate, for it is well known that chemical action goes on less fi«ickly in solids than liquids, and that a solid dry plate should be influenced by light nt this extraordinary low tempera- ture would be a fact that the old advocates of a mechanical rather than a chemical action as the result of light would not be slow to take advantage of. Zilg'lxtning' Photographs. ^A note on two such photographs taken at Sidney was ivad at the lloyal Meteorological Society's last meeting, and tlie writer gave an explanation of certain e£Fects. The two photograplis referred to were taken with a half-plate lens mounted in a whole-plate camera, and as a matter of course showed distortion at the edges. For example, while the lights of street gas lamps were white specks in the centre of the plate, they were crescent-shaped at the edge. The lightning flashes also were distorted, and we have specially referred to this matter on account of the suggestions in the paper that the so-called " ribbon flashes " may be accounted for by this distortion. It is quite obvious that, if accurate ilepicting of lightning Hashes is to be obtained, every care should be t«ken that neither coma nor astigmatism should play any part in the obtained results. On every account, therefore, it would be advisable; when setting the camera up on the chance of securing flashes, that a lens with asflat a field as pos.sible be employed, and that it be well stopped down. It appears to us that the lightning flash is of such brilliancy, that nomatter liow small the stop employed the appearance would be recorded brief, as is its duration. Phosphorescent Zinc Sulphide. — In a recent number of Comptcs Itendus this substance has been proposed as a photometric tandard by M. C. Heary. The original investigations by which Mr. Wamcrke established the usefulness of the instrument which bears his name are on record, and will not be found out of accord with the most recent investigations. M. Henry's results show that, within somewhat wide limits, which correspond with luminous saturation, the quantity of light emitted by a surface of zinc sulphide, rendered luminous by exposure to magnesium light, is independent of the distance of the light or its duration, and of the thickness of the layer of zinc sulphide. He states that the law governing the loss of luminosity is always the same, though the material itself may have such different characteristics as it would probably have after being prepared by different experimenters by different methods. The actual law is expressed in the formula i'" (t + c) = K, when M is taken as ••oOS, and c as 28'.'Jo. It holds good for thicknesses of layers vary- ing from •45 to '9 mm. Within these limits of thickness the maximum intensity of the luminosity is not influenced by the length of wire burnt, nor by the distance it is held within a limit of 15 cm. of length, and of 28 of distance. STUDIO-BUILDING. III. .\t this stage it might be well to refer to an aspect of the subject that has caused me the receipt of several letters. How much of the roof should be glazed, and how low should the side lights extend ? Here, again, it would be better to reply on broad general principles rather than fix a hard and fast line. Thus if it be remembered that when the blinds and screens used are of good design and construction it is — so far as the actual illumination is concerned — quite immaterial so long as there is a sufficiency of light area. For instance, if the whole roof and sides were glazed, the lighting could be made to assume any character and come from any direction merely by .irranging the blinds suitably. But, unfortunately, there is something more to be considered than the illumination only ; we have to think of the sun's heating rays as they affect the sitters' comfort. So that here the indications are aU in the opposite direction, that is, to restrict the amount of roof area to be glazed. When large groups are to be taken, or on occasions where difficult subjects requiring quick exposures are in hand,tiio need for most light will bo exjieri- enced, and the artist will feel he cannot have too much ; but, as a line must be drawn somewhere, a fair principle to act on will be that not more than one-half of the roof in a ridge roof, that would be the whole of one side, should be glazed ; the rest should be quite opaque, slated by preference, to keep out the sun's heat. This latter point is of such supreme importance that no essa^' or instructions on studio- building can be complete without a thorough consideration of ite bearing. The possibilities of building a studio <)n a low level agdinst a lofty building at its south or west, influence this point to an impor- tant extent, as before referred to, and if two sites, of equal merit otherwise, were under consideration, that which provided an already formed sun-screen in this manner should unhesitatingly be preferred. This subject will ba referred to again in a final chapter on ecreens and blinds. The glazing of the whole length of one side of a rijof may to some appear excessive, but it must be borne in mind that it is the light furthest away from the sitter that has to be relied upon to equalise the illumination on groups, which may possibly extend across the whole breadth of the studio, also a studio to seat the sitter at either end is the present groundwork of our remarks. Of course, a similar effect could be obtained by glazing a portion only of the opposite side of the roof, though, unless carefully done, and its position well chosen, such a method would lead to that cross lighting of the subject which on a face is so ugly and inartistic. Some photographers prefer to make the roof opaque for about two feet from the end, and the plan has many advantages. Its chief die- advantage is that there is then an insufficient control over the light- ing: of the backgrounds. When they are lighted from overhead, and the light aperture screened from the sitter, the effect of the back- ground is but slightly interfered with. However, the main light may be controlled by blinds in any special way, while, if the lighting of the background depends on that of the sitter, very unfortunate results may be unwittingly obtained. The relative disposition of the lights and darks may alter the whole chiaroscuro, and cause possibly, for example, a usually light background to come out quite dark in the negative. As to the side lights, little need be said. If they are continued to about three feet from the floor, that will be quite as low as would ever be necessary, and when too low it could be blinded. Side lights, however, are often useless, owing to the light from sky to sitter being arrested by contiguous buildings. Obscured glas-s of course, as advised, should then be made use of. We have now arrived at an advanced stage with our studio erecting. The walls are built, the roof is on, and the sash-bars are ready for glazing; and this is a point on which many photographers are in doubt : whether to use plain glass, rolled plate, hammered plate, or obscured glass. Instead of answering the questions that have been put directly, it will be better to discuss the general prin- ciples or the governing conditions which may be looked to for guidance in coming to a decision. From a given beam of light direct from sky to sitter — using the word sky to in- dicate either clouds or the unclouded azure — least light will be removed by the interposition of plain glass ; rolled and hammered plate come next ; and obscured, i.e., smoothed, or ground glass in the given circumstances robs the beam the most But there are other conditions. According to the situation and con- struction, the strength of the sheets is matter of greater or less importance. Ordinary window glass can be had of a strength of fifteen, twenty-one, and twenty-six ounces to the foot. The same holds good with obscured glass. The varieties of plate may be had, practically, of any thickness. Under all ordinary circumstances, where no violence beyond the forces of nature is anticipated, glass of the thickness of that represented by twenty-six ounce is sufficient. In the course of a long experience I have seen the results of many hailstorms, and Iiave never found glass of that thickness injured even by the heaviest fall. The country is occasionally visited over narrow belts of a few miles by hailstorms when the stones are of extraordinary weight ; but, though I have seen the windows of private houses facing the direction of a storm literally riddled with hailstones, I have never .294 THE BRITISH JOURNAL OF PHOTOGRAPHY. [May 12, 1893 yet had a roof pane of that weight broken. It is well to note that -the best English glass should be used. There is a cheap kind of foreign sheet on the market, which, though fairly thick, I have been -credibly informed is far inferior to a thinner make of the kind I recommend. It is not only said to be more easily broken by hail stones, but is also liable to crack in situ through slight expansions of the sash-bars from wet or heat, or from trivial strains of the supports through painters on the roof, or slight warping of the timber used. As my object is to give, and only to give, my personal experience, I may here say I have had no experience whatever of metallic sash- bars. I should have a prejudice against them, owing to the need for experiments in lighting arrangements, necessitating the use of nails and screws for suspension, and the impossibility of obtaining such support when metal framework was employed. To assist in coming t(j a decision as to whether glass plain or obscured should be selected, it may be said that every studio builder should ask himself why he should have other than plain glass. In any situation where the studio is liable to being overlooked it will, of course, be a necessity. But granted a free, unobscured light, there is nothing to gain by making the glass translucent rather than trans- parent. But many studios are built in situations where surrounding buildings intervene and prevent a free light entry ; then translucent glass may be a decided benefit. The rule to adopt is for the artist to place himself in any situation in the studio where a sitter may probably be placed, and look round at his sky light and side light. If he sees nothing but clear sky, he will receive most light from the use of clear glass. If, however, in his line of sight buildings are visible, then obscured or other similarly acting glass will bring more light to -the sitter. Supposing a studio to be painted internally dead black, and all the unglazed roof covered over, except such parts as would only permit a view of buildings to be seen by the sitter, then — at any rate, speaking for the face — he would be almost in perfect darkness, except the building were painted or otherwise light in colour. If, then, clear glass were put in the sashes, the darkness would remain •unaltered. But if obscured glass were made to take the place of plain, a great difference would be observed. Those beams or pencils of light which in the first would from_ other directions penetrate the roof, illuminate the walls or floor and not the sitter, would be dis- persed or scattered, and so many would reach the sitter as to give a fair illumination to his features. These are the conditions under which portions of a roof might with ■advantage be glazed. In the studio with very steep roof that I described, and which was built in the old wet-collodion days, I used ground glass for the lower panes, owing to my being shadowed over by an exceedingly lofty building at some distance away. Standing at the sitter's end, in all positions where I might expect to place him, I looked through the empty sash-bars, and got the carpenter to mark, with a pencil, the limit on the bars through which I could see bricks and mortar. These I had glazed with obscured glass ; where sky ■only was visible, I used clear glass. G. Watmouqh Wbb3tbb, F.C.S. CONTINENTAL NOTES AND NEWS. Ammonium Hyposulphite. — M. Ch. Hermitte writes in the Itevuc de ritutogiaphie that the ammoniacal odour given off by ammonium hy posidphite with which several Continental photographers have been experimenting as a substitute for sodium hyposulphite, may be obviated by the addition to the solution of a small quantity of chlorate of potash. This, however, does not apply to all samples of the new hypo that are prepared, considerable variations in its quality Ijeing experienced. M. Hermitte recommends the following bath : — Water 1 litre. Ammonium hyposulpiiite 150 grammes. Chlorate of potash 10 „ Negatives fixed in this bath are said to be beautifully clear, and in the quantity of solution mentioned fifty to sixty half-plates may be fixed. M. Hermitte finds an hour's washing in running water sufficient, but recommends for greater safety a longer immersion. A Platinum Toning' Bath for Silver Prints.— The following bath is recommended by a foreign contemporary: — Water 500 c.c. Sodium chloride 35 grammes. Tartaric acid 8 „ Sulphate of soda 6 „ Chloroplatinite of potassium (12 per cent. solution) 8 „ The salts are dissolved in the order named. The bath is said to give tones much resembling those of platinum prints, and to keep well. Photography and the Falsification of Documents. — It is stated that the Russian Government has instituted a photo- graphic laboratory in connexion with the Courts of Justice, the principal object of which will be the verification of the authenticity of legal and other documents. The laboratory, it is further said, has already done signal service to the cause of justice in this way. Hypo in the DKetol Developer, — Herr Schmidt, of Wies- baden, finds that hypo in the metol developer acts as a retarder instead of, as isfgenerally the case when it is added to the developer, an accelerator. He uses it in the proportion of from 30 to 40 drops of a hypo solution 1 : 100 per each 30 c.c. of metol solution. Society Outings in France. — The plan of photographic instruction in the field, which seems of late to have been adopted by several English photographic societies, is being followed in France. On Sunday, April 9, the Societe d'Etudes Photographiques met in the gardens of tlie Trocadero, Paris, under the direction of the Presi- dent, M. Balagny, for the purpose of photographing a certain view which had been previously decided upon, the development of the plates being subsequently conducted at the President's house. Under experienced direction such a method should be a useful source of knowledge to young photographers. Salted G-elatine Paper. — " Violette," in L' Amateur Phuto- graphe, publishes a plea for plain salted gelatine paper (« la albu- menised paper) which could be sensitised and used according to the requirements of the individual, and he claims that, by its use, better tones than is the case at present could be obtained, that toning would be more rapid, and that yellowness, which is more or less evident with commercial sensitive gelatine papers, would be minimised, inasmuch as the elements of deterioration wojild be absent. Sulphocyanide of Ammonium in Uranium Toning. — Professor Hodolfo Namias, in the liicista Scieiitijtco-artistica di Fotografia, recommends the addition of ammonium sulphocyanide to the uranium toning bath as a solvent of the ferrocyanide of silver and potassium which, he says, is formed in toning, and to facilitate the deposition of the uranium ferrocyanide upon the image. The following is the formula he emplojs : — A. — Potassium ferridcyanide 2-3 grammes. Water 1000 c.c. B.— Uranium nitrate 10 grammes. Ammonium sulphocyanide •. . . . . 50 „ Acetic acid 10 c.c. Water 1000 „ Equal parts of the solutions are taken for use. Purifying Eosine. — Eosine, which is employed in ortho- chromatic photography, is not always found in commerce of a suffi- cient degree of purity for photographic purposes. The following method of purifying it is given : — Dissolve 20 grammes of eosine in 700 c.c^ of boiling water, and, after dissolution, add sulphuric acid 1:10 until no further precipitate of bromofluorescein is formed. The liquid is separated by decantation, and the salt washed and dried. The purified eosine is insoluble iii water, but is soluble in alcohol. May 12, 1893] THE BRITISH JOURNAL OF PHOTOGRAPHY. 20& Tbe Aero-carbon Xiigrbt for Printlngr-out Pnr- po«08. — With a ceUoidin papor iind a nejirttivo of normal density M. KoHurzik liiids tliat. by usin)? tlie aero-carbon light ho can obtain developable ima^ji's in from 20 to 30 minutes, and under a thin nega- tive in 20 minutes, wliile a dense negative taltes from 40 to 4o minutes. With gelatine paper 15 to 20 minutes sufRces, but platinum paper requires from :i to "> hours. The printing frame is placed within a few inches of the source of light. I'HOTO-LITHOGRAPHY. [Photographic Society of Great Britain.] Thk purpose to which photo-lithography is applied with special ad- vantage is the reproduction of a subject where only two tones, as blacky and white, without intermediate gradations, are required. True,'tlier6 are photo-lithographic processes in which the half-tones of the original are broken up into a kind of grain, which gives the idea of haif-tones, as do the fine lines of an engraving. The present paper and demonstration will not include these processe.s, nor be con- cerned with many of the variations that have been made in the practice of photo-lithography ; but an endeavour will be made to clearly show throughout a practicable working method, such as the writer has used with success, and, in the main, such as he has known to be employed in printing works turning out large quantities of excellent work. The'absence of half-tone, and the consequent separation of the gradations of the original into two tones as dissimilar as can be obtained, is, in most of the cases for which photo-lithography is employed, not only no drawback, but a positive advantage. An engineers tracing, for example, has to be copied. There may be pencil marking's, traces of erasure, some amount of soiling, and lights and shades from the cloth lying irregularly, or being creased. In any of the ordinary photographic methods these defects would be re- produced, but in a process devoid of half-tone everything must be either black or white, and so representations of soils and creasing, if not strong enough to show as black, will be got rid of. Thr Genebai, Phinch'i.e of Lithography. The general principle of lithography depends upon the fact that a porous stone imbued with water, especially water containing mucilage, does not readily take to grease, and vice versa. If a draw- ing be made with greasy matter upon a litliographic stone, and the stone be then well wetted, a roller charged with greasy ink will deliver its ink on to the drawing, but not on to the surrounding moist parts of the stone. A paper laid on the stone and subjected to pressure will pick up sufficient of the ink to represent the drawing, and the stone may be rewetted and inked up again for as many prints as may be wanted. Certain additions to the process have been found necessary, and will be described ; but this is the main principle. The first thing necessary in photo-lithography is to have a negative, the shadows of which are really clear. It is also desirable to have dense lights, but this is not essential. Wet collodion is recognised as being the best negative process for the purpose, though, for coarse lines from a clear black and white original, some gelatine plates may be made to serve. I always use wet collodion, and I believe that to be almost the universal practice in commercial establishments. It is of course much easier to get a suitable negative from a pure black- and-white subject than from one in which blacks and wliites are deficient in purity, and some establishments insist upon having a drawing made with Indian ink and on Bristol board. However, it is often necessary to copy a subject which presents greater difficulties. I have here a letter more than twenty years old, written to me by a well-known artist. It is rather soiled and creased, and the ink (which, of course, was of the ordinary kind) has faded in parts. Illustrating some of the words is a pen sketch, which I have selected as the subject for the demonstration. Of this I have made two nega- tives (wet collodion). One, which is of full intensity and shows the paper as of fairly solid opacity throughout, looks, to those not aware of the special quality required, to be the better. It is, however, a full half-tone negative. The lines where the ink is still black are transparent, but in other part", where the ink has been thin or has faded, there is a good deal of deposit. Such a negative is not suited for the present purpose, for, although by deep printing on the sensi- tised transfer paper the faint lines might be made to show, there would then be a spreading and thickening of the more transparent lines. The second negative, which is of the kind required, shows the lines throughout as clear as the margin. The white of the paper is not 80 good, every soil and irregularity shows strongly, but these an be masked oat ; or, if they print sufficiently to lake tbe ink oo he transfer, can easily be cleaned ofT the stone. PilKrAIlATIO.V OP THE rHOTG-l.lTlKJOnAPHI : TjlAXSKKB. The principle concerned in preparing a photo-lithographic transfer is this: — Certain organic substances, such as gelatine and albumen, combined with a bichromate, undergo a change when exposed to tlie light, in virtue of which they are no longer soluble, and do not even absorb water. When, therefore, a film of bichromated gelatine is expo.scd under a negative, a greasy ink may be made to adhere to th& parts affected by light, whilst the unaffected parts when imbued with water will not take the ink, or will permit it to be removed. Paper prepared with gelatine for photo-lithographic transfer is an article of commerce, but if preferred can be made at home. The paper should be of firm, good quality, or it may split up in manipuln- tion. Gelatine such as is u^d for photographic emulsion, tolerably hard, may be swelled in water, and dissolved by heat. The strength may be conveniently one to ten, and the solution must be warm, enough to allow of easy flowing. Floating in a di.sh is best, but; means must be taken to keep up the heat during the time the requisite number of sheets are being floated. The paper is sensitised by immersion in a bath of bichromate. Bichromate of potash is generally used, and it has been recommended! to use a solution nearly saturated, about an ounce and a half to the pint. I have more generally used a rather weaker solution, about an ounce to thepint,and have even got good results with half that strength. The objection to a very strong solution is the rapidity with which the paper goes bad. It is generally advised to add ammonia to the sensi- tising bath until the deep orange colour becomes changed to a yellow^ I have not found this an improvement. When the paper is softened in the bichromate solution, it may bo hung up to dry ; but a plan^ which I much prefer is to squeegee it on to a sheet of talced glass,, and leave it to dry there'. There are several advantages about this method : — 1. The surface is fine and smooth, and the paper may consequently be pressed into more intimate contact with the negative. 2. For the same reason the ink may be applied more evenly, with- out having to be forced into the depressions of the grain of the paper.. o. The sensitised surface of the paper is kept out of contact with the air whilst drying, and until it is required, when it may be stripped and taken direct to the press. 4. The paper being dried in an expanded condition, and applied iB> that state to the negative, there is very little, if any, distortion from expansion of the paper by moisture when applied to the stone.* The objection that I have heard raised to drying on talced glass is- that there is a tendency for the paper to stick, and, in short, to refuse- to strip. I have never known this occur sinct; finding that ease of stripping depended entirely upon a vigorous rubbing in of the talo. Take a little powdered talc (French chalk) and with a cloth rub a clean glass hard until the surface appears to be matt nearly all over. It mi.y afterwards be rubbed until polished again, but the effect remains. The grain of the matt is so fine that it is of no consequenco, and the plate may be used many times in succession without any further rubbing or application of talc being required. All loose talc is, of course, dusted away before use. The paper, stripped from the talced glass, is printed from the nega- tive in the usual way. The exposure is not long, and may be judged to be sufficient when the lines show as a clear brown on a yellow ground. The ground may even print through to a certain extent, as a faint image may be made to part with the ink whilst the stronger parts retain it. Inking the Tbansfke. The prim taken from the negative is covered with a thin film of transfer ink. This may be done in various ways. A very good plan is to roll up a lithographic stone with a thin film of ink, and then lay the transfer on it and pass a few times through the press, reversing the stone to ensure equality of pre.'sure. Another plan is to roll on to the transfer paper direct. The end of the paper may be turned over the edge of a piece of glass so as to reach the back. The glass is then laid on another glass, and so the paper is held during the- rolling. In either case the first thing is to get a thin, even coating of ink upon a roller. A special ink is used, containing a large proportioa of fat. It is sold as lithographic transfer ink, and being very stiff re- quires a little thinning before use. For this purpose lithographie * To make up for this distortion, it is customary with some photolitho- grapliers to take the negative somewhat smaller than is required for the finished print : h\it then, as paper expands unequally when wetted, it will l)e neceis-oary to note which way the paper is to be cut, .ind even then the result will only be of the requiieif size in one dimension, and will exceed or come short of it in another. 296 THE BRITISH JOURNAL OF PHOTOGRAPHY. [May 12, 1893 varnisU is commonly used ; some, ho-\vever, talie a fat oil, such as palm oil, and others turpentine. The diluent, whichever it is, is worked up with the ink by a palette knife on a stone, and then by repeated rolling ; the stone and the roller are evenly coated. It is desirable that the coat of ink on the transfer be thin, or the fine lines may liaag together. The image should just show through the ink. The roller used is an ordinary lithographic leather roller, which, however, should be of fine texture. For very fine work some use a velvet roller. Small subjects, and, indeed, larger ones if time is not an object, miy be coated with ink by a pad of linen or other rag merely, and the use of a roller may be dispensed witli until the transfer is on the stone. The pad should be first dabbed with a little ink on a stone or piece of glass until it will distribute a thin even .film of ink. Placing the Tbansfek on the Stone. When the transfer is inked, if turpentine has been used as the diluent, it is left for some time, say, twenty minutes. With other diluents it may be proceeded with at once. It is laid in water, or merely floated on, face upwards. This is perhaps the best way, but then no water should be allowed to get on the face in parts, or these will be less strong in the image than the rest. When the gelatine has absorbed sufficient moisture (which can be told by the unexposed portions being raised a little above the lines), tlie transfer is laid on the slab, held down as before described, and the roller passed over it a few times. The ink will now, for the most part, leave the whites, and the blacks will be strengthened. The transfer is next sponged with water until the spaces between the lines are perfectly clear. Sometimes the rolling off is omitted, and sponging alone is relied on. The transfer is tlien partially dried and put on to the .stone, or, as is often done, it is dried and damped again by placing it in a moist blotting-book. The transfer is best put on to the stone the same day as made. If kept several days, it may refuse to take properly. The stone, having been cleaned and polished with snake- stone used with plenty of water to prevent scratching and dragging, is, after drying, and sometimes slight warming, laid on the bed of the press. Warming is necessary if the stone is colder than the air of the room, as in that case a film of water may be deposited. The damp transfer is put in place face downwards. " Some thicknesses of paper are placed on it, and it is then passed a few times through the press, the stone being reversed and the back of the transfer redamped half way through the process. A corner is lifted to make sure that the impre.ssion has taken well on the stone, and then, after damping the back of the paper, it is pulled off entirely. If there is a difficulty, warm water is used. The stone is sponged, and then gum water is' rubbed all over. This helps to keep the whites clean, and the lines from .spreading. The gum water should be allowed to dry, and then the stone is .sponged, and ink from the transfer is reinforced by roll- ing, or rubbing with a pad, with ordinary lithographic ink slightly thinned with varnish or turpentine. If a pad is used, enough ink should be taken up to show as a smear. Before touching with the pad, thick gum water is poured on to the stone, and rubbed in at the same time that the ink is strengthening the deposit on the lines. Phkpabing the Stone. The stone has to go through a process called etching, which, however, does not dissolve it to an appreciable extent, but cleans it up. Before etching, the image is protected by being dusted over with hncly powdered resin. Tlie excess of resin is lightly dusted off and the surface of the stone is sponged. If there are any blemishes m the way of ink on the stone where not wanted, they can be removed at this stage by a scraper, or a narrow slip of snake-stone bometimes powdered talc is used instead of resin. The etching fluid IS a very dUute solution of nitric acid. The strength of the acid is determined by its effect on the stone. If effervescence takes place in from five to ten seconds, the acid is about right for strength After sponging off the acid the stone is again gummed and dried Ihe stone xs now again sponged, and the ink, which has been clogged by the resin or talc, is washed off with turpentine The stone 13 agam sponged clean, and, a little thick gum water beinc^ first poured on, the image is partly brought back by rubbing with a pad of linen that has been touched on to the inky slab. The stone is once more sponged clean, and wiped with what is called the damping cloth which, as Its uaine implies, is always kept damp enough to leave the stone moist. The damping cloth is a material of a soft muslin character, without any dressing in it. What is called butter cloth such as 18 sold for the purpose of wrapping round rolls of butter, is swtable ; enough to make a good handful— say, a yard— is sufiicient. PaiXTING. The stone is next inked up by rolling with the ordinary litho- graphic ink, slightly thinned with lithographic varnish. The amount of ink left on the image may be regulated by the thickness of the coat on the inking slab, by the dilution or softness of the ink itself, and by the manner of rolling. Heaviness and slowness of rolling deposit ink freely, whilst lightness and quickness tend to remove it from the stone and clean up the lights. A piece of paper is laid on, the tympan lowered into place, and the print made by pulling through the press. The first print may be a little weak, and yet, after about a dozen pulls are taken, it may come up of full strength. After each print is pulled, the stone is damped again before re- inking. Wiping with the damping cloth is generally sufficient. If the stone itself appears to take the ink in places, rubbing with a sponge will generally clean it ; but, if there is a difficulty, clean it off with turpentine, and, after sponging with water, bring back the image by rubbing with a cloth, charged with thinned ink as before directed, taking care that there is some thick liquid gum on the stone at the same time. Of course the assistance of a practised lithographic printer will save some failures, and be of great use during the first essays in the printing part of the work. It would be perhaps as well at first to confine oneself to making the negative, and from that the photo- litho transfer, and hand the latter over to a lithographer for printing from. If only one or two prints are required, it may suffice to make the photo-litho transfer, and consider that as the final result. At all events, this will afford good practice for those commencing to work the process. W. E. Dkbenham. AJSIIBOL FOR DEVELOPED PRINTS. I HAVE made some thousands of bromide prints, and used some hundreds of gallons of ferrous oxalate developer during the past ten years. Recent events, however, have worked a change. Ferrous oxalate has been an old and valuable servant, but I am afraid it will now have to be deposed and be considered practically defunct. " Requiescat in pace." For printing in bromide — and one is almost compelled to adopt this method when days are short and leisure scanty — I find amidol to be a particularly satisfactory developer. Things are getting simplified nowadays, for we are able to develop out negatives and prints in the same solution, and fix them side by side in the same bath, while we can (and it is a good riddance) say good-bj'e to the acetic-acid clearing bath. The developer made several months ago, viz., amidol I'O, soda sulphite 100, water I8'0, was used. I have not met with any trouble so far with reference to the keeping qualities of this new developing agent. A solution, ten per cent., of potassium bromide was also prepared. Exposure of the bromide paper should be full and ample, the addition of a few drops of the bromide solution keeping the development well under control. The whole arrangement is quite easy, the requisite exposure ascertained by a trial print, the remainder are exposed, and may then be immersed in a bath of clean and very slightly (at this time of year) warmed water. One part of stock developer is put into another dish with two or three parts of water, and bromide solution ad libitum. The prints may be developed singly or in batches, are then transferred to a dish of clean water, and thence to the fixing bath ; afterwards, a thorough washing to complete this stage of the operations. This is of the first importance to thoroughly elimldato the hypo — hence fixation should be complete. Then, after thorough washing, a final bath of hydrogen peroside and water, about one ounce to the pint should be resorted to ; then a final rinse in water. The tone of the deve- loped print is quite pleasing, and leaves little to be desired ; but if we wish, various colours, more or less rich and warm (and rather less than more, by the way), are easily produced. If the print be, and this is, perhaps, preferable, on thin paper, I don't know of anything better than the old mercury bath, followed by a wash in ammonia water or a solution of sulphite of soda. One advantage I find in the use of mercurti is that no lessening of density results. Whatever intensifier {?) is used, the subsequent washing is to be ample. We may then safely immerse the print in the alkaline solution. Eder & Toth's bath may be used, e.g. : — Ferridcyanide potassium (5 parts. Nitrate of lead 4 „ Water (distilled) 100 „ followed by a thorough washing, then the print toned by various chemicals. It seems, having in view the exposure, density, and length of time in the mercury bath, or Eder & Toth's, possible to get an extraordinary variety of tone ; in fact the process is extremely in- May V2, 189i] THE BlUTISH JOURNAL OF PHOTUOBAPHY. 207 terestiiifr experiineiitiiUy. At the same timo it would require very careful working to pet a dozen prints exactly alike. If toninp he n'sortwl to 1 have a likiiif; for the U«d and ferridcyanide hath. The print should he fully expo.sed atid over-developed, this bat h taking " a lot out " of the print. After bleachinff and wa-shing we (ret, with a ten per cent, solution of cupric sulphate, a really j^ood reddish brown, and very often the print will be the better for a .second dip in a bath of weak ammonia water. Wn'Mni/ in water, not to be lengthj-, follows, a piece of cotton wool helping at this .stage to get a thoroughly clean surface, and the print.s are then dUispended to dry. For opals amidol should be very suitable; in fact, looldng at the ea.se of working, keeping qualities of the solution, aud the fact that a clearing bath is not a necessity, to say nothing of colour of positive, one is inclined to a«k what further use have we for ferrous oxalate ? J. Pikb. CENTRAL PHOTOGRAPHIC CLUB, Fleet-lane, LuDciATE-ciKcus. VIoN. TiiBASUBER : John Howson, " Brockenhnrst," Ilford, E. Executive Committee : Messrs. Birt Acres, R. Beckett, Thomas Bedding, Austin Edwards, Thomas Fall, T. E. Freshwater, John A. Hodges, E. J. Wall, and II. Snowden Ward. The following circular is in course of circulation : — The want of a photographic club and institute with a permanent home in a central position of London, and easily accessible from the principal railway termini and by the chief omnibus routes, has been for gome time felt, and, after several meetings of gentlemen interested in the matter, two public meeting.s have been held, and it has been decided to at once aupply the deficiency. Numerous premises liave been seen and reported npon by the Executive appointed at the first public meeting ; and it is proposed, and negotiations are on foot to secure premises at the above address, consisting of base- ment, ground, first, and second floor, at what is considered a very reason- able rent. In the basement twelve dark rooms could be fitted up, and leave sufficient space for setting up apparatus for enlarging by artificial lifiht. The room on the first floor, after structural alterations, will be eulliciently large to seat 230 persons. It is also proposed at first to provide a smoking-room and library, and other club conveniences. It is proposed at first to utilise the refreshment-rooms in the Memorial Hall-buildings, with which communications will be made. The excellence of the usual catering and the moderate charges have, after actual experience, been highly 8)K)ken of. This arrangement will be terminable at any time, and the Club Committee can take the supply of refreshments entirely into their own hands. While the social element will be a strong feature in the proposed Club, technical photographic meetings, demonstrations, lantern entertainments, exhibitions of pictures, apparatus, hij applied to Journalism. The lectme, which was illustrated by means of fifty-Beven gpecially prepared lantern pictures, may thus b6 briefly Mammarised. ^, j, " - .,.. . •*-'~i The lecturer, in his opening remarks, pointed out to what a great ex - tent the journalism of the present day owed a debt to the art of photo- graphy. Such papers as the Grajilw- and Illiutrated London Sewn are almost wholly illustrated by pictures produced by photography. The application of photography has, of course, tended to almost extinguish the wood-engraver, but such an extinction most always be expected when manual labour is replaced by machinery. As an instance, he re- ferred to the substitution of reaping machines, which have thrown manual labour into the corner. Photography has ousted, to a large extent, the wood-engraver, just as photogravare is ousting the ateel- engraver. It is to be deplored, and we sympathise with those who are thus thrown out of employment ; but, on the other hand, we must con- gratulate ourselves on the steady advance photography is making year by year. The existence of such papers as the Cuts, of which there are many would be practically impossible were it not for the art of photography. Mr. Hepworth then showed a copy of one of the earliest papers, pub- lished in 167!), entitled Duiiieslic Intelligence; or, Notes from City and Country. The original had two columns on either side, and consisted of one small sheet eight and a half inches by six inches ; only tliree advertise- ments appeared in the paper, and he contrasted these with the big triumphs of printing in the present day — e.g., tlie Telegraph, Standard, and Daily News, which contain from fifty to sixty columns of closely printed matter, and are crowded with advertisements. The want of illustration was felt at a very early date, and rough wood- cuts very soon appeared ; a specimen — St. Christoplier — was shown on the screen. The original is supposed to be in the possession of Earl Spencer. The picture showed that the woodcut contained some really good work in it, rough as it was. This kind of illustration first appeared in the seventeenth century. A ludicrous specimen, representing a flood in Nottingham, caused great amusement. We must remember that there were few artists in those days, and people had to be content with such drawings. Still greater difficulty was experienced in getting some one who could cut the blocks for the press. A portrait of Charles I. and his Queen, and another of Isaac Pennington which appeared in the Mercurius Ciricus in the seventeenth century created some amusement when Mr. Hepworth informed the members that these portraits represented different people at different dates on account of the costliness of the blocks. This custom is still in vogue, as will be seen when our thoughts are directed towards the annual "penny panorama of the Lord Mayor's Show." He referred to a paper of some years ago entitled, The Illustrated Times, in which it was the custom to insert old blocks from which the heads of the people had been excised and new ones substituted. A picture of the marriage of the Princess Royal and the Prince Frederick (afterwards the Emperor) was represented in this way. The same block was in an old block representing the wedding of another couple years previously. For many reasons the Observer may be called the first illustrated newspaper. An example from that paper in 1827 was shown, illustrating the dire effect of using steam for locomotion, and it caused much laughter. The copper-plate process was sometimes used. It differs from the woodcut in this respect : in the former the lines are cut in, and in the wood block the lines are raised. In the copper plates the lines are sunk, rolled with ink, the surface cleaned, the ink remaining in the lines of the picture. It was the practice to first print the newspaper in the ordinary way and then pass it through the copper-plate press in order to obtain the engravings. Specimen copper-plate engravings from the (Ibserrer, representing Nelson's funeral car, were shown on the screen. Another class of picture known as the broadside then appeared in the papers. Sheets were issued having a rough picture at the top and perhaps underneath some lines or history of a murder. Some of these old broad- sides may now be purchased in our back slums. A specimen was shown, Britannia bringing Nelson home from his last victory. In March, 1820, a picture appeared in the Observer representing the house in Cato-street where the conspiracy was first hatched. A broadside representing the execution of Mary Perry in 1834 was also placed upon the screen. Comparing these broadsides with those in the Daily (Iraphic, it will be seen how we have advanced in the art of pictorial illustration. An amusing picture, representing " the first banns," was also exhibited. Having treated of the historical portion of his lecture, Mr. Hepworth traced the history of the Daily Graphic woodcuts from their first con- ception to their appearance in the paper. The back of a wood block was shown, and it was explained that, owing to the difficulty in getting box- wood more than three inches in diameter, the block had to be composed of several small pieces bolted together. These pieces were distributed between several engravers, and, after the drawing had been engraved, the pieces were rebolted together, an impression taken in wax, a stereotype produced and bolted to a wooden block, which was then ready for press. The method of engraving was described, and an illustration of the en- gravers' studio placed upon the screen. Mr. Hepworth stated that in (be pre-photographic days the engravers very frequently spoiled the work of the artist, much to the annoyauce of the latter. Examples of original drawings and of photographic reproductions were placed upon the screen, and it was difficult to distinguish one from the other. The lecturer then explained very fully the method of printing the Daily Graphic. He fS THE BRITISH JOURNAL OF PHOTOGRAPHY. [M:iyli, lOi stated that this paper was produced at the rate of 50,000 copies an hour, five machines being used. The paper, he said, passed through each of the machines at the rates of three and a half miles in fourteen minutes. Type-composing, the formation of paper moulds, cylindrical casting, and the general working of a machine were fully explained from the illustrations. The method of drawing and photographing the pictures was very lucidly explained. Balloon sketches, telegraphic instruments, &c., were each in their turn dealt with, and Mr. Hepworth concluded his lecture with a photograph of a group of artists, amongst whom were noticed Professor Herkomer and Mr. Frank Holt. A vote of thanks was unanimously accorded to Mr. Hepworth for his lecture. Later in the evening the Club resolved to affiliate with the Photographic Society of Great Britain. rORFAESHIRE INTERNATIONAL EXHIBITION. The Forfarshire Exhibition was held last week in the Beid Hall, Forfar, the task of organization devolving upon Mr. K. Whyte, Forfar, and Mr. W. 3. Anckorn, Arbroath, assisted by a local committee. Exhibits were onjview from New York, Chicago, Italy, Vienna, and Germany ; and, but for a hitch as to time, pictures from Eussia, India, and Africa would also have been entered for competition. The Exhibition was well sup- ported by the principal exhibitors throughout the country. For Judges, the Committee engaged Mr. Walter D. Welford, London ; Mr. Marshall Wane, Edinburgh ; and Mr. Adam Diston, Leven. The following were their awards : — Class I., confined to Forfarshire amateurs : Silver medal, Peter Feathers, Dundee ; bronze medal, G. Mackie, Brechin. Class II., open amateur landscape : Silver medal, T. M. Brownrigg, Guildford ; bronze medal, A. H. Bishop, Helensburgh. Class III., amateur genre and portraiture : Silver medal, withheld ; bronze" medal, John E. Dumont, New York. Class IV., professional portraiture: Silver medal, W. J. Byrne, Kichmond, "Winnie;" bronze medal, J. H. Hogg, Kendal. Class V., professional genre : Silver medal, Bobert' Terras, Markinch ; bronze medal, W. J. Anckorn, Arbroath. Class Vl., open class enlargements: Silver medal, Alexander Bros., Glasgow; bronze medal, W. J. Anckorn, Arbroath. Class VII., pro- fessional landscape : Silver medal, Robert Terras, Markinch ; bronze medal, J. H. Hogg, Kendal. Class VIII., ladies only : Silver medal, Mrs. Bennetto, Italy ; bronze medal, Mrs. Amy Wameuke ; hon. mention, Margaret Watson. Class IX., lantern slides : Silver medal, T. M. Brownrigg, Guildford ; bronze medal, Edgar G. Lee, Newcastle ; hon. mention, W. Taverner and W. C. Beetham. Class X., champion class : Gold medal, W. M. Waineuke, Glasgow ; silver medal, J. A. Dumont, New York ; bronze medal, Robert Terras, Markinch. Special awards : Gold medal, withheld ; silver medal, W. J. Byrne, London ; bronze medal. Miss Hall, Brechin. Apparatus section : Bronze medal, A. H. Baird, for Todd-Forret flash lamp. ©ur lEiJitotial Eatlt. The Official Catalogue op the Beitish SbctiOix of tiir Chicago Exhibitio.v. A CONSIDEBATION of the fact that this catalogue of the British Section fills 5.j6 pages, too;ether with 110 pages of advertuiements, almost appals one at the probable immensity of a complete catalogue embracing all nationalities. That portion relegated to photography is prefaced by a brief summary by Captain Ahney, from -which we learn that, as regards the application of photography to scientific purposes, it is believed Great Britain is very much on the same level as other countries. Its use s in medicine, chemistry, astronomy, physics, mineralogy, gunnery, and other branches of pure and applied science, has been very fully demonstrated at the various learned societies, wliere a very large proportion of contributions are illustrated more or less hy photographs. He gives credit to the Eastman Com- pany for having given impetus to flexible film photogi-aphy, and the form of roller slide in which to use it. A\'e are pleased to see that a large number of pictures are contributed by the photographers of the United Kingdom. Metol-Hauff. London : Fucrst Broa., 17, Philpot-lane, E.G. Messrs. Fuehst have sent us samples of the metol manufactured by Herr Hauff, and which, as we learn from their circular, has been patented in all countries. These samples are put up in small pill-bo.x like tins, each containing thirty-five grains of metol, which, we may say, is in the form of a dry, white, sparkling powder. Adhering to the instructions for use by which they were accom panied, the contents of one case (thirty-live grjuns) were dissolved in eight ounces of water — that of the New River Company in this case — and when dissolved, three-quarters of an ounce of sulphite of soda wore then added. This, so far as we can perceive, is likely to remain good for an indefinite period; it therefore forms a useful stock solution, and may be labelled A. Solution B contains the same quantity of water — eight ounces — and three-quarters of an ounce of carbonate of potash. IVow, in accordance with the proportions in which these are mi.^ed, so does the character of the negative depend. For example, and in the case of studio portraits, the addition of one part of B to three of A, will give an ordinary average negative ; while, if a soft negative he desired, one-half part of B will suffice for the same quantity of A ; equal parts of A and B, with a third of its bulk of water, gives a hard negative. It will thus he seen that this developer lends itself to the production of any class of negative desired. We may add that, for the development of landscape negatives, a large admixture of water, even up to an equal hulk, is recommended. But soda can be used equally as well as potash. The proportions recommended are : — A. Water 1 pint. Metol 130 grains. Sulphite of soda 3 ounces. B. Water 1 pint. Soda crystals 2^ ounces We have only to add that the Metol-Hauff acts very admirably as a developer, and keeps well in solution. Since writing the foregoing we have received from Messrs. Arthur Schwarz & Co. samples of Dr. M. Andresen's metol, between which and that above noticed we have not been able to discover any notice- able difference. The formida for development issued with this latter is as follows : — Water 1 quart. Metol • J ounce. Sulphite of soda 7 ounces. Carbonate of potash 85 „ Bromide of potassium y'sf ounce. To photographers who prefer to work with separate solutions the following is recommended : — A. Water 1 quart. Metol J ounce. Sulphite of soda 7 ounces B. Water '■'• quarts. Carbonate of soda 7 ounces. Of these one part of A is mixed with three pi\rts of water for use, bromide of potassium being added as required for the prevention of fogging. The preparations of Dr. Andresen reach us both _^in pill- box and cartridge form. La Biblioteca de Fotogkafo. Paris ; 4, Rue Antoiue Dubois. Milan : Lepage ct Cie, 11, Via Santa Radisondji. This little volume has for object the provision of a sectionised list of all published works, so far as can be ascertained, that relate to photo- graphy. It should be useful for reference, as the subjects are given in French, German, Italian, and English. Willis's Phoiooiiaphic Mounts. Messrs. Willis & Co, Limited, Long-acre, have submitted to us samples of various styles and sizes of mounts enamelled, plate sunk with paste down tint, plain-toned, dark enamelled in various colours, ivory surface, plain and gold blocked, embossed, gold bevel, &c. The mounts are not only all in excellent taste, but are beautifully finished, and appear to be very cheap. A specially pure, plain mount contains seventy-five per cent, of paper, which Messrs. Willis say is not usually found to tliat extent in pliotographic mounts. As showing the magnitude of Messrs. Willis's business, it may be mentioned that over 100 hands are employed in the production of the mounts. They supply samples free. " To EVKSY PhOTOGBAI'HEB." This is the title of a brochure issued by the firm of Taylor, Taylor, & Ilobson, Leicester, relating to the standard lens flanges and adapters made on the principles recommended by the Photographic Society of Great Britain, and for accuracy in the construction of which this firm has acquired a great and well-deserved reputation. Having had May 12, 180.) THE BRITISH JOURNAX OF PHOTOGRAPHY. 280 occasion to avail ourselves of their services in the adoption of several lenses to the one system, in view of the comfort tliat has, in conse- quence, been experienced, wo can strongly advi.se those who have a variety of lenses to have them all brought under the standard, feeling assured this will conduce to their comfort as much as it has done to ours. The pamphlet contains a list of prices. Thb Bbomibk Lamp. JIarioii & Co., Soho-squave, W. This lamp, which is constructed luvJer Groom's patent, is primarily intended for contact bromide printing, for which it seems admirably adapted, but it can mal^e a useful lamp for all-round purposes. The lamp proper, which is shown in the cut isolated from its framework. has its wick operati'd ou by a pinion, and its flame is backed by a well-designed reflector. When inserted in its casing, no light is i^mitted save through the aperture in front, and this governed by slides fitted respectively with either colourless glass or ruby and yellow, the last two of which can be combined if desired. The lamp is so constructed as to consume kerosine without the necessity for employing a chimney. Total darkness is obtained by a shut-off actuated by a lever in front. The burner is regulated from the outside. Photogbaphic Accessories. Mn. F. Brbbsfoed, U, Bridge-street West, Battersea, S.W., has introduced several acce-^sories calculated to prove of use to the photo- grapher. The " Eclipse Focussing Cloth " can be instantaneously adjusted over the camera, excluding all hght, and leavinn: the hands free. .Several buttons and elastics ensure perfect fitting to the camera. The " Paragon Changing Bag " is de.-^igned for those who object to changing plates by touch. It is provided with sleeves for the admission of both hands, there is a ruby window in front, an '■lastic strap to pass over the head, and a pair of eye-holes protected by ruby gla.ss, through which the operation of changing plates in the field may be watched. .Vccompanying this is the " Eclipse Light-tight Case " for use with it. This is strongly made of black and ruby fabric, and holds six plates. Mr. Beresford has timed the introduction of these useful accessories with prudence. The ABC Gtidk to the Making of Autotype Phints. By J. R. Sawtkr. Londou ; The Autotype Company. The increasing interest now being taken in carbon printing renders the present a fitting time for issuing a reprint of the admirable manual written a few years since by the late ,1. K. Sawyer, director of the Autotype Works," and which in this edition has been brought up to date. When, six years since, we reviewed this Guide, we characterised it as a practical quintessence of all that had been previously written on carbon printing, and expressed ourselves sorry for the intellect of the man who, with such a Guide in his hands, could fail to produce excellent work. This, in effect, is all that we can say 'f this reissue, which is replete with all that is good and practical, ind embodies the experience of this most experienced firm up to the present time. It should by all means be perused by every one who aspires to be a pigment printer of any eminence. It is embellishcl by a full page illustration, Sieep)/ Hollow, by Colonel J. Gale. La Fotoqeafia : Secondo i Proceasi Modemi. Compendio Teorico- Pratico Del Doctor Luigi Giopoi. Second edition, Reriaed and Enlarged, with 472 woodcuts and 10 plates. Milan : Ulrico Hoepll. Db. Gioi'Pi's work extends to nearly T.W pages, and in that space he compresses a compendium of the theory and practice of modem photo- graphy, which, if not quite complete— as, for example, in the case of photo-mechanical printing— is at least full enough in other respects. The book is a compilation from recognised sources of information, which are acknowledged, the illustrations of apparatus, &c., being of an international character. It opens with an examination of natural and artificial light in their relation to sensitive surfaces, while succes- sive chapters treat fully of the camera and accessories ; the lens in its various forms; exposure; shutters, ,S:c. Other divisions of the book are devoted to the negative ; its development ; after-treatment ; re- touching ; printing processes ; and many other departments of what may be termed pure photography. The book, which is dedicated to the Prince of Naples, Honorary President of the Milan I'hotographic Society, is a monument of industrious compilation, and should prove a useful work of reference for Italian photographers. RECENT PATENTS. APPLICATIONS KOR PATENTS No. 8956. — "Improvements in the Manufacture of Sensitive Plates and Films for Photogi-aphic Purpose.s, and in the Treatment of such Plates and Films after Exposure in the Camera." C. E. Pettitt. —Dated May 4, 1893. No. 9072. — " ' The Phrenoscopic Camera,' being an Instrument for the Pro- duction of Binocular Perspective in a. Single Photograph." S. N. GonnoN and 5. C. Wicks.- Oated May 6, 1893. No. 9106. — " Improved Dark Slide for Exposing Celluloid Films in Photo- graphic Camera." E. H. YiTca.—lJaied May 6, 1893. No. 9107. — "Improvements in and in connexion with Photographic Cameras known as Hand or Detective Cameras." H. G. M. Contbrare. — Dated May 6, 1893. No. 9118,—" Improved Means for Operating Photographic Shutters." C. J. WoLLASTON and J. Stuart.- />rtterf May 6, 1893. PATENTS COMPLETED. A New or Improved Photooraphic Acces.sobv for Portrait Photography. No. 9721. Edmond Stanley Lalder and Jambs Stack Laudbr, 30, Westmoreland-street, Dublin, Ireland. — April 1, 1893. This invention relates to a new or improved accessory for use in connexion with portrait photography, whereby such work may be carried on more economically and with greater convenience, and more artistic effect than hitherto. The invention consists in the use of a sheet of clear glass, tinted or other- wise, arranged between the sitter, or object to be photographed, and the camera Tliis sheet of glass is utiliseil as a medium to carry decorative designs, floral or otherwi.se. The advantages of this arrangement are as follows : — 1. The interposition of the sheet of glass tends materially to soften the lights and shades in the ])ictures produced. 2. The operator is enabled to use designs of such a nature in front of the sitter as would be quite impossible by any othfr means. 3. It is rendered jiossible to photograph a variety of objects apparently occupying different planes, while they are iictually in one plane, thereby ensuring perfect sharpness and definition for all distances. 4. When the designs upon the glass represent flowers, they photograph in front and arounil the figures in all naturalness of real flowers, but being upon the one plane they are much sharper and better defined than real flowers could possibly be under the circumstances. 5. Economy, ina.smuoli as tlie power is available at all times of the year of adding to portraits all the efl'ects to be obtained from the choicest and rarest plants. I.MPROVEMKNTS IN PhOTOGRAI'HIC CAMERAS AND IN FlI.MS KOR USE THEREIN. No. 13,926. .loHN Feather.stonehauoh Parsons, Siddington House, Kingsdownparade, Bristol.— ^^n7 1, 1893. This invention relates to ])hotographic cameras and to films for use therein. According to this invention the films are .irranged in a pack after the manner of a pack of cards, and arc placed in a carrier inside the camera box and acted upon by a spring tending constantly to draw the carrier towards the lens. Each film is separate from the others, and each is provided with a tongue or .strap, which is extended forward to the front of the camera, and made to project beyond a recess formed at the front for the reception of the straps or tongues. The latter may either be made in one piece with the films, or be separately made and .ittached to the films. After exposure of the foremost film, it is drawn np from the pack through the medium of the strap or tongue aforesaiil, and is pulled over the edge of a ledge, on which, after having been drawn, the film lies face downwards. The spring before mentioned as tending to draw the cariers towania the lens advances the pack of films so that each film i.i brought into focus in turn, and is drawn up after exposure as above described. Kestraining strips or stops are provided for the films, so that they cannot be .idvanced beyond the proper focus. 300 THE BRITISH JOURNAL OF PHOIOGKAPHY. [May 12, 1893 The films as they are drawn out of the pack are piled one over the other on the ledge aforesaid, and can t* removed at will. The chamber into which they are drawn is light-tight. , - .. Tlie operator is enabled to ascertain, by observing the outer ends of the straps or tongues, the number of films which have been exposed, and as each film is drawn up the operator may sever the tongue at the recess through which it projects. Improvements ik PHOTocnArHic Ca.vbhas. No. 9819. Conrad Beck, 68, Oornhill, London, E.C., and Joseph Thacher Clarke, Boston, Massachusetts, at present residing at 3, College-road, Harrow, mMlesex.— April 8, 1893. OCB invention relates to photographic cameras intended for the separation and manipulation of a pack of sensitised films or cards, such as that described in Clarke's Specification, No. 11,891, of 1890. In apparatus of this description a frame or holder, turning upon an a-xis, contains a pack or series of films or cards, wliich are separated and deposited by simultaneously acting selecting devices working upon tlie front of the holder. When released from the said holder and deposited in another pack or series, the films or cards have hitherto been held in position by a retaining device or presser foot, which was raised when a sheet or film was to be deposited from the liolder, and was afterwards returned to bear upon and retain the deposited films or cards. Our present improvement has for its purpose to replace the beforementioned retaining device or presser foot by a fiexible and movable dividing band or septum, which, when the holder is in position for an exposure, intervenes between this and tlie pack of deposited films, and which is capable of being turned out of the way by the rotation of the holder when this is moved for the purpose of rele.asing and depositing the exposed films or cards. Such a septum may be formed of a strip of cloth or leather, a band of exceedingly liexiblc metal (as, for instance, sheet steel or phosphor bronze, about three or five- thonsandths of an inch thick), or of any similar suitable material. When it is introduced into a photographic camera having a chamber for the reception of the deposited films or cards situated at the bottom of the ease, at right angles to the holder, it has been found advantageous to hinge or otherwise attach the lower edge of the septum to a low transverse partition strip, so con- structed upon the bottom of the camera body as not to exclude the light of the lens from the holder. Tlie upper end of the septum may be similarly attached to the cross-bar or Hap, which forms the back of the holder and provides the abutment for the spring tending to press the i)ack of unexposed films forward against the separating devices upon the front of the holder. The width of the septum may be made nearly equal to the clear interior width of the camera itself, while the length may be somewhat greater than the distance between the partition to which its lower end is attached and the bar or flap upon the back of tlie holder to which its upper end is attached. If the chamber for the rece)rtion of the exposed and deposited films be situated behind and parallel to the holder, the flexible septum may be attached by its lower end to the bottom of the case at some point between the receiving chamber and the holder, and by its upper end to the top of the holder itself. In both cases it is requisite to reverse the direction in which the holder has hitherto been rotated, in such wise that the top of the holder is moved away from, instead of towards, the lens. By this motion, after a revolution of 270° or tliereabouts, the septum is lifted out of the way of the falling films or cards. When the holder is in its normal position ready for an exposure, the septum intervenes (as before said) between the padi of unexpo.sed and the pack of exposed and deposited films, thus preventing the latter from falling into the body of the camera when this is placed \ipon its side. At the same time it shields the pack of exposed and deposited films from the light admitted through the lens during the act of expc^ure. The notable advantages of our invention — as compared with the presser foot which it is designed to supplant— are economy in manufacture, and the assur- ance that by no irregularity or other failure of reciprocal action on the part of the pre.sser foot can a sheet or film be dropped into the body of the camera between the lens and the holder. Improvements in the Majiufactukb ok Transi'ahent Materials, and the Application of the same to Photographic and other Purposes. No. 7.^67. Thomas Christy, 25, Lime-street, London, E.C.— April 8, 1893. This invention relates to certain improvements or modifications in the manu- facture of transparent tissue described in my Specifications, No. 12,230, 1890, and No. 13,917, 1888, and it has more particularly for its object the rendering of such or similar material suitable in photograpliy for dark-room illumination, or its application to the manufacture of photographic apparatus and appli- ances, such as transparent changing bags, chambers, covers, window blinds, films, and the like, and for other purposes. In carrying this invention into practice, I make a solution of gelatine or an equivalent substance, and 1 incorjiorate therewith a ruby colouring matter of a nature which does not allow the actinic rays of light to pass through, such as red and yellow aniline, or other dyes in the.se colours. 1 also most generally add certain chemical agents which will render the glutinous substance insoluble, such as a salt of chromium ; or I subsequently subject the gelatinised sub- stance to a fixing bath, such as chrome alum or other agent having the same eflfect. I also most generally combine glycerine with the glutinous matter for the pur{)Ose of imparting flexible properties to the same. I more generally pre- pare the glutinous solution substantially as described in my SpeciHcation,12,230, 1890, and I employ the same as a film upon glass or otherwise, or I treat suit- able paper silk tissues or other fabrics with the glutinous solution, sub- stantially as described in the hereinbeforementioned Specification, 12,230, 1890, and 1 apply the products as covers for camera screens, to the manufacture of developing bags in the form of muffs, or otherwise for photographic and for other purposes. But, instead of simply proceeding as above described, I more generally prefer for the purpose of this invention to produce a transparent tissue substantially as described in my Specification, 12,230, 1890, and as above referred to, and then to cover the surfaces of such material with a coat of siccative oil or a suitable varnish, and after drying the material is ready for the purposes herein intended. The desired colour is embodied with the material as herein described, or as described in my Specification, 12,230, 1890, and sometimes, for the purpose of intensifying the colour, I also mix a suitable colouring matter with the oil or varnish with which the material is to be coated. Instead of producing a gelatinised base material as above referred to, I may also prepare a suitable paper, or silk tissue, or other material, with a solution of glycerine. I more generally employ an unsized or partially sized long-fibred paper for the purposes herein intended, and I saturate the same with a solutioft of glycerine in water, more generally a proportion of three to four parts of water to one jiart of glycerine witli which I incorporate any desirable dye, or 1 dye the paper first to the required colour. The material is then dried, and 1 then saturate it with a suitable siccative oil, or varnisli, and I more generally employ a quick-dryiu" fiexible varnish. I then dry the material again, after which it is ready for the puqioses herein intended. With the object of pro- ducing very intense colours, and also to cover any minute holes in the material, I may also combine some of the colouring matter with the oil or varnish with wliich the matterial is to be treated. I wish it to be understood that 1 may also apply the improved material for some of the purposes named in my Specification 12,230, 1890, such as for surgical purposes, and in this case colouring matters are more generally omitted. The patentee claims : — 1. The manufacture and application of material, sub.stantially as herein described, for purposes in photography requiring the- exclusion of the active rays of light. 2. The application of the improveit material for surgical and other jmrposes. 3. The improved material manu- factured substantially as and for the i>urposes herein described. flUeettngs; of Sboct^tteiS, MEETINGS OF SOCIETIES FOR NEXT WEEK. Date of Meeting. Nune of Society. May 15 Camera Club «™ „ 15 Dundee Amateur „ 15 FiUebrook Atheuwum „ 15 Hastings and St. Leouarda ... „ 15 Leeds Photo. Society tt 15 Richmond „ 15 South London t, 16 Birmingham Photo. Society I, 16 Brixton and Clapham >t 16 Hackney ,» 16 North London ,> 16 Paisley , M 17 Brechin y, 17 Bury *• 17 Leytonslone „ 17 Manchester Camera Olnb It 17 Photographic Club , n 17 Southport , ,t 17 Southsea , ** 18 Birming:ham Photo. Society M IS I Ciimeni Clnb M 18 i Glossop Dale , „ 18 » 18 „ 18 „ 18 „ 19 » 19 „ 19 „ 19 .» 19 „ 20 Place of Meeting. Hull London and Provincial Oldham Charing- Cross-road, W.C. Asso. Studio, Nethergate, Dnudee, Fillelu-ook Lecture Hall. Mechanics' Institute, Leeds. Greyhound Hotel, Richmond. Hanover Hall, Hanover-park, S.E. Club Room, Colonnade Hotel. 376, Coldharbour-lsine, Brixton. 206, Mare-street, Hackney. Canonbury Tower, Islington, N. 9, Gauze-street, Paisley. 14, St. Mary-street, Brechin. Club Rooms, 13, Ap:ar-street, Bnry, The Assembly Koom.«, Hifrh-roa*!. Victoria Hotel, Manchester. Anderton's Hotel, Fleet-street, B.C. The Studio, 15, Cam bridge -arcade. 3, Kinp-'s-road, Southsea Club Room, Colonnade Hotel. Charing Cross-road, W.C. 71, Prospect -street, Hull. Champion Hotel, 15, Aldorstrate-st, The Lyceum, Union-street, Oldham. Oxford Photo. Society j Society's Room:*, 136, High- street, Cardiff | Croydon Microscopical i Public HaU,George-street,Croydon, Holiaorn | Leamington Trinity Church Room, Morton-st. Maidstone "The Palace," Maidstone. Hnll 71, Prospect-street, Hull. PHOTOGRAPHIC SOCIETY OP GREAT BRITAIN. May 9,— Ordinary Meeting, — the President (Captain W. 4e W. Abney, C.B.^ F. U.S.) in tlie cljair. The Brixtou and Clapham Camera Club were admitted to affiliation of the Society. Judges for the Society's Exhibition. It "wa-s announced that the following prentlemen had been appointed Judge* for the forthcoming Exhibition of the Society : — Dr. P. H. Emer.sou, Colonel J. Gale, Messrs. F. Hollyer, F. >L Sutcliffe, and J. B. B, Wellington, with, as scientific experts, Messrs. Chapman Jones and Andrew Pringle. Tinfoil as a Sltport for PHom-UTHOGBArHic Transfers. Captain A. M. Mantell read a paper on this subject, describing a process of Mr. Husband, who is employed in the Lithographic School at Chatham, for the substitution of tinfoil for paper in the preparation of transfers, so as to prevent expansion and consequent distortion. Captain Mantell showed com- parative examples illustrating the superior qualities of picture produced by the use of tinfoil. [Wc shall print tite paper i?i r.rfcnso iu a future number.] Mr. Leon Wauneuke, in the coursfi of a discussion which followed, suggested the use of silver foil, which he had successfully employed in another photo- mechanical process. It was easily obtainable commercially. In answer to an inquiry by Mr. Bolas, Captain Mantell said the foil could be used for retrausfers from the stone, having the advantage that it gave no dis- tortion, but he did not lay stress on that, as the foil transfers were awkward to keep. The President said that some twelve years ago tinfoil was employed n! Chatham for the piwpose, and he was enamoured with the results obtained, but Mrty i*, im] THE BiRitisfl Journal bP pkofoaRAi'HY. 801 their grent clifHcnlty which Captnin Mantell had surmounted, was that of olitaining suilabie foil. Ho did not agree with Captain Mantell that proce«s blocks Wire not rcquireil for military work ; he held that they were of the greatest use. A vote of thanVs was jiassed to (.'aptaiu Mantell for his paper. The I'liKsrDKNT then read a paper on The r.ie a/ Rapidly hi.. ■ • <.■..,■.,>;,.,. Surf acts, w\i\\ rcfei-cnce to their anplirabillty to ascertaining the • . y of shutters, the duration of Hiishlights, the comparison of the i :-\ik. effects produced by direct sunlight with the iiniyl. acetate lamp, &c. lie al.so said it was pos.sible by such means to measure tlie duration of the electric .spark by employing a rotating reflector with the instrument. .Mr. G. L. A uiiKN'BHOnKE explained a similar instrument for measuring the speed of shutters, which ho had described before tlie Society some years ago. In reply, the Pkesidknt pointed out that tlie instrument referred to only demonstrated the speed and not the efliciency of the shutter, and was inapplicable to such work as the comparison of sunlight and candlelight. Me also objected to the fact that its results were given in the form of arts, which were not so readily measured. A vote of thanks was passed to the President for his paper. LONDON AND PROVINCIAL PHOTOGRAPHIC ASSOCIATION. ilAY 4, 1893,— Mr. Alexander Cowan in the chair. .Mr. A.shley Cowan was elected a member of the Association. CireiUars relating to the new Central Photographic Club were distributed among the members. Kesiqsation of Mk. R. P. Drage, Hon. Secrktaiit. The resignation of Mr. Drage, Hon. Secretary, having been announced, in conse(iueuce of the action of a jirevious meeting in requesting the chairman of that meeting to enter on the minutes a resolution moved by Mr. Beckett, referring to the remarks made in the spiritualistic press as to the attitude of the As.sociation over spirit photography, The Chaib.man saiil it was an unfortunate thing that Mr. Drage had taken a personal view of a matter which was strictly to do with the Society, He was sure the members would receive the resignation with great regret. Mr. A. Haddon endorsed the chairman's expression of regret. The Society had been in a better .state under Mr. Drage than under his predecessors, and it was to be regretted that he had taken the view of the matter that he had, and should have considered it such a personal insult as to throw them over. He (Mr. Haddon) hoped that Mr. Drage would continue with them as an ordinary member. Mr. Drage had always had a pleasant welcome for both members and visitors, and his resignation must cause them all great regret. Mr. R. Beckktc echoed all that had been said by the previous speakers, and said that, in moving the resolution in question, nothing personal was intended for Mr. Drage. Mr. W. E. Debenham said that Mr. Drage's services had been extremely valuable to the Society ; aild, indeed, no Society could possibly have a better secretary than he had been, but Mr. Drage had, in his opinion, certainly com- mitted a mistake in refusing to enter the resolution on the minutes. A fonnal resolution having been put to the meeting, Mr. Drage briefly acknowledged it. Mr. T. E. Freshwater acted as hon. secretary ^-o tcm. during the meeting. The Association's Technical Lectures.— III. " Developers." Mr. E. J. Wall delivered the third of the series of the Association's Technical Lectures, his subject being Derehpers. Mr. Wall said he would not touch on theory, but he would controvert Messrs. Hurter & Driffield's statement, that a photographer had no control over his results, by saying that a photographer could so control them as to get what he wanted, either by the stain of the developer, fog, or difl"erent colours of the deposit, which so affect the printing qualities of the negative as to give him enormous power over those results. Mr. Wall then proceeded to discuss the practical advantages of the principal develoi)ers, first of all pointing out that a developer consisted of the develojiing i^ent, the restrainer, and the accelerator, and indicating the action of each. Hfaving dealt with fenous oxalate (formulas for which, as well as for the other developers, will be ajipended to the paper when it is published), he jiassed to pyro, both with ammonia and the alkaline carbonates. In regard to the •sidphites he said he thought they had some action on the developed image, as it seemed to him they altered the character of the print by keeping the shadows I. ir.'ind had a tendency to ]irolong the unprintable numbers given bya Warnerke I itometer. For a standard jiyro developer for scientific puraposes he recom- !:)• i..!ed the formula recently published by Mr. Cowan, and by means of diagrams jioiuted out that prolongation of the time of development altered the ratios be- tween the high lights (which he sujiposed to have been developed through) and the half-tones and shadows, es|iecially with thinly-coated plates. Hydro- quinone gave more unprintable number's than any otlier developer. As a restrainer with it lie preferred acetic acid to bromide. Eikonogen gave such softne.'-s that it was difficult to avoid want of contrast with it. It should be employed at a temperature of not less than 65°. Rodinal was a very con- venient one-solution developer, and lent itself easily to modifications. In cases of under-exposure he employed it 1 :60, for over-e.xposure 1 :20, with 10 to 1.. grains of bromide to the ounce, and for ordinary work 1 : 30. Mr. Wall concluded his paper by touching on amidol, which he recommended to be used freshly mixed, with a stock solution of sodium sulphite. He did not see the necessity for using alkalies. Finally, he promised at a future date to treat of metol and glycin, and said developers in use might be ilividcd into two classes, the slow and gradually working ilevelopers, which lend themselves to modifi- cation, and rapid developers, with which the whole of the image appeared nearly simultaueou.sly. The ClLviltstAN said Messrs. Hurter & DrifTield defined a perfect negative a.s the true inversion of the original. Mr. Wall said he obtained what he wanted by the aid of fog, but whether that was the way to get a perfect negative was another thing. Mr. R. OllllJ) Baylbt doubted whether [lyro was the only developer which staineeri- ment on an unexposed plate, showing how, with the aid of ammonia, fog can quickly be obtained. Hackney Photographic Society.— The Annual Meeting was held on Tuesday. A very successful season had- to be recorded, the membership (although several removals had taken place) keeping up to 115. The Treasurer reported a fair balance in hand, and stated the weekly meetings had done much to improve attend.anccs. The election of officers resulted : — Presideul • Mr. F. Houghton.— CoHMcfy.- Messrs. W. F. Barker, G. J. Avent, F. W. Gosling, G. Hawkins, R. Beckett, W. A. Hensler, Dr. Roland Smith, and E. Puttock.— //ort. Treasurer : Mr. J. O. Grant— iSTon. Secretary : Mr. W. F. Fenton-Jones, 12, King Eeculiarities of the Sandell plate, and the treatment of it. For development lie recommended Messrs. Thomas & Co.'s "cyclol" developer, composed as follows : — Hydroquinone, 30 grains ; eikonogen, 100 grains ; rodinal, 9 drachms ; -sulphite of soda, 2^ ounces ; carbonate of potash, 2h ounces ; water, 20 ounces. Use 1 part to 7 parts of water in the summer, and in the winter time 1 part to 3 parts of water. The fixing bath should be as strong as 8 ounces of hypo to a pint of water. A longer time should be allowed for the fixing and washing of the plates, owing to the thickness of the coating. Mr. Fry, in conclusion, claimed the following advantages for the Sandell plate : — (1) "Special merit for hand- camera work ; (2) peculiar fitness for interior work • (3) a practical cure for halation ; (4) a better atmosi)heric effect and a longer 'range of gradation ; (5) exposure is practically unimportant. Examples of work were passed round and examined. A question was asked: '"What is the best background for photographing Mowers for lantern slides ?" It was answered, "A black velvet, brown paper, or a dark-coloured plain background. Two new members were elected, and five nominations were read. Attendance, fifty-two. Croydon Microscopical and Natural History Club (Photographic Sec- tion).— May T). — Jlr. ,1. I!, (iotz exhibited several photographic novelties, and explained their working. Tlie chief one was a pair of lenses with a shutter attached — part of a new camera he was about to introduce — whicli could be used at will as a stereoscopic camera, or as a hand camera witli full-sized finder, or as a double quarter-plate. The shutter liad a considerable range of speed, and althougli worl;ing simultaneously on each lens could, when neces- sary, expose them independently. A changing box for large films was .also shown, the films being carried in thin steel sheaths, and exposed in a single dark slide. Mr. Gotz then demonstrated the new Obernetter positive films, the various methods of toning Obernetter gelatine, and celloido-chloride papers, and their development when jiartially printed.; the great variety of tones obtainable were shown in a number of jirints that were handed round. Birmingham Photographic Society.— May 2, Mr. W. Jones in the chair.— About forty-five members iiresent. Mr. Fry gave a lecture on The Uses and Advantagesnftltr Sandell Plate. Mr. Fry described the advantages claimed for multiple films. They are, briefiy : (1) Freedom from halation even with the most trying ^iibjects. (2) Possibility of giving enormously more than a Jiormal exposure, which, with careful tentative development, would give .all detail and density possibly required, and would dispose of the correct exposure ro tern. — I am, yours, 5, Blenheim-cre.icent, W, GELAHNOCHLOBIDE VKRSUS ALBUMEN. To the Editor. Sir, — I think " B. B.'s " difliculty with gelatino-chloride is due to want of scrupulous cleanliness, without which it is impossible to work the paper satisfactorily. I judge from "B. B.'s" letter that he finds his prints dirty after burnishing — dust is burnished into them. The remedy is obvious : as the prints are mounted, they should be placed on frames covered with muslin, and with short feet attached, so that when piled one on top of another an air space intervenes ; the burnisher must be in good con- dition and well dusted ; the prints carefully dusted and lubricated with Castile soap in methylated spirit before passing through (except a roller burnisher is used, which, I need hardly say, is by far the better instru- ment). To avoid abrading the surface, the prints must be thorouffhhj dry : had " B. B.'s " been so, they would not have been " scraped." "They must not be baked to make them dry, for, if all moisture is taken out of the mount, no gloss can be obtained. With care, which ought to be exercised in every branch of photography, no prints need be spoiled in the burnisliing. at least not more than if they were albumen, for even these. I gather, are sometimes spoiled in " B. B.'s " hands by "ordinary Bcratches." Pyro and amidol should not be weighed out in the printing room ; this is sometimes done, and printers are puzzled to account for black spots on the prints. 1 have never found prints on ready-sensitised paper to spoil sooner than those on the home-prepared article, and I think I am right in saying that, if prints on any paper "mottle," the fault will, in all probability, be found elsewhere than in the paper. As to gelatino-chloride versug albumen, looking at the matter from a purely professional point of view, I consider the odds are greatly in favour of the former, for the following reasons : — It is uniform, the sheets cut more economically into photographic sizes, it is perfectly good to the edges, no watermarks, it is beautifully clean back and front, and is almost invariably free from the .slightest blemish, and for these reasons it is cheaper. It is more permanent, as may be tested practically by putting gelatino- chloride and albumen prints, prepared with equal care, side by side in a well-exposed show-case ; it gives more brilliant prints, washes quicker, prints faster (and " time is money "), both innately, and because thinner negatives can be used. Albumen, on the other hand, is rarely uniform ; in many photographic establishments, where carelessness reigns paramount, the bath is per- mitted to vary (I have known it to be used for months, and never once filtered), the albumenising formula is an unknown factor, or is permitted to be so, and the paper sensitised without regard to it. The ready- sensitised paper often comes, even from makers of repute, dirty, stained, and wasteful. In many instances, where years have been spent in acquiring profi- ciency with albumen, gelatino-chloride is expected to be known in a moment. If those to whom gelatino-chloride is new find it at first a bit intractable, they should remember the blisters and measles of its rival. Albumen (except for breakfast) is out of date; it wants careful labelling and placing on the shelf with the wet plate.— I am, yours, &c., ilatj 6, 18'J3. T. FiTzoiBBON Fobde. To the Editob. Sin,— I notice your correspondent, " B. B.," has got into some dilEculties in working gelatino-chloride paper, and I want, in. all brotherly love, to help him out. I have abandoned albumen paper entirely for more than six months now. I use P.O.P. and work as under. For enamelling it is the best thing I have ever struck, but collodionise your plates first if you dont want opalines. For ordinary work, when the prints are mounted, rub them over with a damp, clean sponge to take off any dirt, and to re- move the fluff which will adhere to them from the blotting-paper that 18 used to press them in contact with the mount. Then, mark this "B. B.," stand them up on end face to the wall till dry, this will prevent dust settling on the tacky surface. Now the burnishing. When I began to burnish P.O.P. on a bar burnisher, I spoilt dozens. I used to heat the bar hotter than Gehenna, as in old albumen days, and, of course, it frizzled aU the gelatine off the paper. Now I find it only necessary to make the bar about ax hot as the hand will just bear for a second, say, about 300* Fahr. Previous to burnishing, I give the print a dose of my old lilvei print lubricator, but when dry mb it all ofT, or the prints may be streaky. The prints should now go through the machine like oil, and have a nice gloss. Kn passant, 1 may say I have never met with the marks referred to by " B. B." Probably these originate in the filing bath ; but the one thing that delights me in gelatino-chloride papers is the entire absence of measles, a malady to which our old friend albumen was very subject. — I am, yours, <&o., '• Otheixo." May 3, 1893. IIEGULATORS. To ihe Editor. Sin, — I must certainly say, when Mr. Birrell asked for information respecting a regulator for oxygen and hydrogen gases, I was under the impression that it was a regulator for condensed gas at high pressure of not less than COO pounds per s(iuare inch. But by his latter remarks, and also judging from a print sent me by him of bis apparatus, he evidently means a low-pressure regulator such as would be used upon the ordinary house gas mains of, say, from seven- tenths to four inches water pressure. Mr. Highley speaks of these for use with oxyhydrogen jets made by Mr. Parkinson as far back a« 1870, but I don't profess to know the date of their origin. 1 only know there are more than I should like to enumerate. Again, Mr. Birrell speaks of his anti-friction cock. Does he suggest a lubricant of any fatty matter ? If so, he will find his anti-friction coek meet with little success. Gas compressors strongly discourage the use of grease of any kind whatever. Before Mr. Birrell proceeds further with his regulator he should get a cylinder of gas from the Scotch and Irish Oxygen Company to test it with. — I am, yours, &c., R. R. Beabd. ()2, Ahcot-road, Bermondsey, S.E., May 2, 1893. "ART VERSES PHOTOGRAPHY." To the Editor. Sib, — At the present juncture of the endleas argument on Art versir Photography (let them both have capitals) it was interesting to read in the Saturday lieview of last week the following in their criticism of Mr. W. B. Davis's picture : — " . . , . Notwithstanding his wonderful sincerity and the almost per- fect photography of his eye . . . ." "i. tr-* Should wc take this as a compliment to Mr. Davis or as a compliment to photography ? — I am, yours, &c., Frederick H. Evass. 158, Osbaldeston-road, N., May !), 1893. EnslDew to CorrcsponHents. „* All matters intended for the text portion of this Joubnai., including queries and Exchanges, must be addressed to " The Editor, The Britlsh JouENAL OF I'HOTOOBAPHT," 2, York-street, Covent Garden, London. In- attention to this ensures delay. \* Correspondents are informed that wc cannot undertake to answer com- munications through the post. ,* Communications relating to Advertisements and general business affairs should be addressed to Messrs. Henby GREENWOOD & Co., 2 York-streeti Covent Garden, London. Photographs Registebkd : — Walter Azemboy Smith, Southampton. — Portrait of Dr. Pcrrin, Bwhoj' 0/ Cotumhia. John Stephen Brown, Bridgwater.— PJiO(oyraph of crayoM draictn^ o/Samiui Taylw Coleridge. Everitt Edward Hiblin^, UaitUtone. — Portrait of John C»ckov!. George Henry Lawrence, Cardiff. — 0ti4 photo^jraph of a Welali Sun day *' Fisid *■ Chih. D. Ross. — We know nothing whatever of the Company. Gil Bi.as.— The ad. I have been given to understand that there will be enough in an old bath by what it has extracted from the coUodionised plates that have been excited therein. 2. In the case of the iodide getting iu excess, what is the result and remedy ? 3. Also of insuffi- ciency ? " — 1. There will be quite enough iodide in solution to warrant the addition of more nitrate solution without any further addition. 'J. Add dis- tilled water, by which much of the iodide will be precipitated, then filter, and lastly, add crystals of nitrate of silver to bring up to the strength required. 3. Coat a plate with collodion, and allow it to remain immersed in the silver bath for one hour. J. T. Kennisu writes: "I forward you a mounted print, which is much spotted, as you will see, and will thank you if you will give me your opinion as to the cause. The paper used was ' double allnmienised ; ' fixed twenty minutes (in hypo, four ounces ; water, one pint) ; hypo neutral to litmus paiwr ; hypo used fresh ; mounted with Glenfleld starch, m,ade fresh, and used as soon as cold ; sponged while damp with clean water. Cartes-de-visite, whole-]ilates, and 12 x 10, produced at the same time, under exactly same conditions, are perfectly free from spots ; washed all niglit in syphon trough. Cabinets only show these spots.." — Seeing that the spots only make their aj^pearance on the cabinet prints, and assuming that in their after-treat- ment there is no difference made, the only suggestion we can make is, that our correspondent test the mounts. It is possible the trouble has its origin in them. During the summer the steamship Cily of Richviond will make several pleasure trips to the fjords and mountains of Norway. The first trii> is from Liverpool on May 20. Messrs. Staveley & Co., of 102, Shaftesbury-avenue, W., are the London agents, and will supj^ly all particulars. Messrs. Adnitt & Naunton, of Shrewsbury, have sent us a short rhumi of objects of interest to photographers visiting Shrewsbury. It is embellishetl with several picturesque views. Should the Conventiou carry out a half- formed intention of holding their meeting in Shrewsbury on an early occasion, such a list as this will prove very useful. Mr. E. II. Fitch, of 34, Angell-road, Brixton, will shortly introduce a celluloid film for photo-mechanical purposes ; also a very light double slide- film carrier, and other novelties. West London Photographic Society's Dinner. — The annual dinner of this Society took place on Tuesday last, May 9, at the Frascati Restaurant, Oxford-street, the President (Mr. J. A. Hodges) in the chair. The ch.allenge cup won by the Society at the recent Crystal Palace E-xhibition was on view. The President, in proposing the toast of " The Society," took occasion to comment on the fact that, although the Society had been adjudged winners of the Champion Cup at the Crystal Palace, no awards had been made to individual members, and thought some explanation of the circumstance was due. Mr. W. England responded for "Kindred Societies," Mr. Thomas Bedding (The British Journal ok PnoTOGRArHY) and Mr. E. J. Wall (Ainateur Pholographer) for " The Press," and Mr. T. R. Dallmeyer for " The Visitors." OONTBNTB. PAai THE rapid drying OF QKLATINE NEGATIVES 289 stripping and REPLACING NEGA- TIVES WITHOUT THEIR EXPAND- ING 2!I0 EXPERIMENTS WITH MULTIPLE- COATED FILMS 290 STUPIO-ISUILDINO.— III. By O. WAT- MOUGH WEBSTER, F.C.8 298 CONTINENTAL NOTES AND NEWS .... 294 PHOTO - LITHOGRAPHY. By W. E. DEBENHAM 295 AMIDOL FOR DEVELOPED PRINTS. By J. PIKE 9C Paox central photographic club 237 photography applied 10 jour- nalism 2ot forfarshire international ex- hibition 2w our editorial table 2f< recent patents 2™ meetings of societies ■"» exchange column ■»' correspondence «« ANSWERS TO CORRESPONDENTS -v- THE BRITISH JOURNAL OF PHOTOGRAPHY. No. 1721. Vol. XL.— MAY 19, 1893. :NOTrCE— PICTORIAL SUPPLEMENTS TO "THE BRITISH JOURNAL OF PHOTOGRAPHY." Tt is our intention from time to time to issue with The British Journal lip rnoTOGRAPiiY pictorial supplements illustrating subjects of popular interest, and reproduced in the highest ■style of photo-mechanical work. We have no doubt this feature will prove very popular with our readers. The first illustration will be given with the JouRXAii of Friday, June 2, and, as tlie publishers anticipate a largely increased sale for that issue, orders for advertisements ind extra copies should be given as early as possible. INVERSION AND REVERSION OF IMAGES OX THE BINOCULAR FOCUSSING SCREEN. "When a stereoscopic image is focussed on the grovmd glass of a binocular camera, the image presented to the eye is seen to have undergone a total reversion, not merely in respect of its heing inverted, for that is the case with every camera image, but also in regard to the relative displacement of the near and distant objects on the screen when viewed stereoscopically, could such be done by the neophite. The stereoscopic photographer cannot, with his unaided vision, ascertain the effect of relief by the inspection of the camera image iw the same way as he can when examining the finished j^rint in the stereoscope; and this to some extent inter- poses a difficulty in the selection of the best point of view in order to secure the degree of relief which an artist of taste invariably likes to characterise his binocular pictures, neither, on the one hand, such protrusion of foreground objects as to cause the scene to look like a model, nor, on the other, such a lack of it as to impart a feeling of flatness to the united photographs. Some who have not bestowed sufficient attention to the subject have imagined tliat, by employing a stereoscope to examine the image projected on the camera focussing screen, the desired end ought to be attained ; but the futility of this is established by a single trial, for it will be found that the effect obtained is pseudoscopic, that is, the near objects appear listant, while the most distant ones are brought near. We >hall apply the "similia similibus curantur" principle to this ;>re8ently, and bhow in what manner, by looking on the groimd -rlass through a pseudoscope, the detired relief can be seen. A pseu-s j.rsrn-", mounted the distance of the ■eyes ajart, with the hypotheuuses to the inside, so that each eye is directed to a surface inclined to its axis. In ours there is provision for an adjustment, by which the reflecting surfaces can be slightly inclined towards each other, so as to direct the eyes without any straining to any object situated from within a few inches to infinity. When a scene is viewed through this, it is neither magnified nor reduced, nor is its brilliance apparently diminished, but the singular effect is obtained that the distant objects are brought close at hand, while the nearest objects — such as a vase of flowers on a table in the window of the room from which the observation is made — is projected into the far distance, the near and distant flowers in the vase obeying the same law, that of visible direction. In virtue of this the nearness or distance of any object is ascertained by the greater or less convergence of the optic axes. Were the mere inversion of a camera image desired, this could be secured by the time-lionoured expedient of placing a mirror at an angle witli the ground glass of the camera, and by looking down into this mirror, viewing in it the image on the focussing screen, not upside down as formerly, but erect, a reversion from right to left being still left uncorrected. This, however, affords no clue as to the amount of the relief or stereoscopeity of the scene focussed unless by crossing the axes of the eyes, the right side being viewed by the left eye and vice versd. An examination by a pseudoscope would effect the same end. The best way to employ this instrument is to view with it the direct image on the ground glass without caring that the image is seen inverted. Throw a large focussing cloth over the camera, and then use the pseudoscope as would be done in the case of an eyepiece held a short distance from the ground glass, and adjust the prisms till only one image formed of the coalescence of the two is seen. But by far the readiest and most convenient method of judging stereoscopic efl'ect in the camera is by the unaided eyes after they have been subjected to a very slight degi-ee of training. Hold the head fiom twelve to sixteen inches from the ground glass, and cover the inter- space with an opaque cloth. Now direct the axes to a point midway betwetn the eyes and the camera screen. This may at first be done by interposing a pencil or the finger at the midway point. It will now be found that the crossing of the axes at this point will have had the eftectof causing tLe right eye to see the image on the left, the same being the case with the left eye. This may prove troublesome ju^t at the first attempt, but after a few trials it will be found to be singularly easy. The combined image thus seen is the stereoscopic one, precisely as it will appear when printed on paper and viewed through a stereo- scope, witii this exception, that the camera image will be upside 300 THE RRITISfl JOUKNAL OF PHOTOGRA.PHy. [May 10, 1893 down, a matter of but small consequence to an experienced photographer, who can in most cases better judge the effect of the uftimate picture when the image is inverted than when it is non-inverted, the consequence, doubtless, of practice. EXPERIMENTS WITH MULTIPLE-COATED FILMS. Resuming these experiments with a view of removing, if possi- ble, certain apjiarent anomalies, a .special collodion emulsion was prepared wliich, while moderately sensitive (for such an emulsion) was capable of giving per se, and with ordinary de- velopment, a perfectly clean image of good vigour and free from fog. The " pellicle " was washed with rather more than ordinary care, in order to ensure the entire absence of soluble salts. In our earlier experiments it was mentioned last week that development was extremely slow in starting, as long as five minutes elapsing in some instances before any action was visible, while in other cases it began almost immediately. This we traced to mechanical causes connected with the collodion film, and it was one part of our new trials to remove as far as possi- ble these uncertainties. In some instance?, in the earlier experiments, the plates were exposed wet, i.e., without drj-ing the collodion film, in which case they were well washed with water before development, in order to remove the ether and alcohol and allow the developer to attack the films in a uniform manner. In other cases the collodion film was dried before exposure, under which circumstances it became necessary to flood the films with alcohol in order to reopen the pores of the collodion, and afterwards to wash well with water. It was this treatment we found that caused the difteience or uncertainty in behaviour, for the gelatine film became charged with varying proportions of water, which, assisted by the same protective action of the collodion film, prevented the free access of the developer. By working constantly under like conditions, it is true that comparative results would be obtained ; but we were strongly of opinion that this preliminary absorption of water by the gelatine film exercised an important action in modifying the general character of the results — a view which we had subsequently reason to believe is the correct one. One way out of the difficulty was to charge the collodion emulsion with a substance of the nature of a " preservative " — using the term in the sense in which it was employed by old dry-plate workers — which, being soluble in water, would render the compound film permeable to the aqueous developer ; but, though this was tried, the introduction of the preservative did not seem a desirable complication, so it was relinquished in favour of the simpler plan eventually adopted. This consisted in coating the gelatine plate with collodion emulsion imme- diately before exposure, and postponing the development until nearly the whole of the solvents had volatilised without leavino- the film absolutely dry. In this manner, and developing in a dish in the manner usual with gelatine plates, the "greasiness" caused by the small remaining traces of ether and alcohol was easily overcome, and the developer passed directly into the films both of collodion and gelatine. Under these altered circumstances, the behaviour of the compound films becomes quite different, and more in accord- ance with what might have been anticipated. For instance the high lights or sky of a landscape appeared,'almost instantly on the application of the developer, owing to the rapidity with which an impressed collodion film produces its image. Under the conditions in which these plates were exposed, the sky or strongest high lights were the only portion of the plate in which the exposure was long enough to impress the collodion alone ; hence these portions only showed reduction as soon as the developer was applied, the remainder of tlie picture being formed by the slower action of the gelatine film. In our article last week we specially mentioned the extra- ordinary behaviour of an unwashed collodion emulsion in pro- ducing an image practically without exposure, or under such circumstances that, if exposed alone, without the gelatine film, it would have been quite insensitive. We have repeateil that experiment several times, with precisely the same result ; but, although there is unmistakably an image formed upon the collodion film, we have arrived at the conclusion that much of the increase of density shown is the result of a general veil that seems inseparable from this method of developing the collodion emulsion. In fact, although, as we have said, the emulsion employed is capable of working by itself without any fog or veil, it will not bear the protracted application of the energetic developer necessary for the gelatine film. It must be remembered that the development proper of any direct image upon the collodion film would be complete in a very short time — certainly under a minute, and probablj- before that on the gelatine had commenced — and consequently, while the gelatine image is progressing, that on the collodion is being subjected to all the influences of fog, which, under the circum- stances, it is unable to altogether resist ; and yet the gelatine film itself reacts upon the collodion in restraining the fog, as may be proved by scraping off a portion of the gelatine film before coating with collodion, when on development the portions of collodion unbacked by gelatine will be found as completely reduced as the sky. In all the experiments made we have therefore been careful to note as far as possible the effect produced by veil or fog as distinguished from a definite image. Before describing the individual experiments we may briefly describe the general character of the results. The collodion emulsion employed is one, as we have said, of moderate rapidity, and requiring, under the circumstances of light, lens, and aperture, from twenty to thirty seconds' exposure, to give a perfect picture when used alone, when the exposures given to the compound films averaged about one second, the subject being an open view from the window in a good light. Under these conditions, it is obvious that the actual exposure received by the collodion portion of the compound films is quite iusutti- cieut to impress it except in the skj- ; but that is done easily, with the result that the sky always becomes visible within three or four seconds of the ajiplication of the developer. Yet iu all mstances, or nearly all, where the development of the compound film has been completed, a developed image has been visible upon the collodion film. In order to prove this beyond doubt, we hiive gone to the trouble of stripping the collodion film from the gelatine when the precise nature of the deposit — image and veil — is palpable ; but this trouble is not necessary, as, owing to the peculiarly metallic nature of the deposit on collodion, the image is per- fectly visible as a positive, and that, taken in conjunction with the alteration in density produced where a portion of the collodion film is rubbed off, will show i)recisely how much work has been done by each film. There is one point that may be noted iu connexion with the rapid formation of the image upon the collodion film that has May 10, 1893] THE BRITISH JOUKNAL OF PHOTOGRArH Y. :J07 some importance as bringing these experiments more into line with the Samlell j)late than would otherwise seem to be the case. In the latter plate the first or outer film is the more sensitive, and therefore naturally develops first, the effect of that development passing on to the next film to modify it more or leas. In the collodion-coattd films, although the first or apparent film is by far the slower, it is the first acted upon by the developer, and in the same maimer the action of this first development is transmitted to the underlying film, and pro- duces most powerfully modifying effects, as we shall show. llather out of curiosity than .as having a direct bearing on the rest of the experiments, a gelatine plate was exposed, and suhsenuently coated with collodion emidsiou before development. According to the experiments of Captain Abney of sixteen or seventeen years ago, the collodion film should have shown an image ; but, bej-ond a slight veil from over-development, no etfect was produced upon the collodion whatever. A second plate, coated liffore exposure, and exposed for precisely the same time, gave an entirely different result ; for, whereas in the first the sky was thinner in the coated portion than on a part of the plate that was left uncoated, owing to the resisting action of the collodion film, in the second plate the coated portion of the sky was very much the denser, though, on removing a strip of the collodion film, it became much thinner than the uncoated portion, proving that the greater part of the image was on the collodion. With the normal exposure the general result was greater vigour, especially in the high lights ; but, as the exposure was increased, the contrast became less increased, but general vigour, more especially in the half-tones, became the rule, that is, supposing the development to be carried out to its full extent ; but, when the latter is stopped at an early stage, the results are very curious, for, if the collodion film be removed, the image of the high lights will be found to be completely in the collodion, the gelatine showing either completely clear glass or absolute reversal. That this is not due to over- exposure, or to any other cause but the bromine given off from the collodion emulsion film, can be proved by leaving a portion of the plate uncoated, when an entirely normal image will be formed. Moreover, if the development be stopped at the early stage on a portion of the plate, and completed on the rest, the first portion will thow the reversal, the second a normal image. Another jjlate was coated over a portion of each of its surfaces, back and front, with collodion emulsion, and exposed through the glass in order to show how much action the absorption of light by the collodion film had. The bare gelatine film exposed through the collodion, beyond its want of sharp- ness from diffusion, showed comparatively little difference from that where the collodion had not intervened. But the collodionised surface exhibited not the least action, for the denser gelatine film through which the light had to pass before it reached the collodion had altogether protected it from the light, and, except the usual slight veil from over-action of the developer, no image of any kind was seen. The result of these experiments shows conclusively that each separate film exercises a very distinct action upon the others in develojjment, and it seems probable that, the greater the difference in the sensitiveness, the greater will be the action set up. It seems also proliable, but that remains for future proof, that, by so arranging the relative rapidities of the difterent films, a film absolutely proof against errors of exposure may be made, as claimed by Mr. Sandell. GUMS AND (iLUPX It will be desirable in our purview of this subject not to ciiit some consideration of the so-called "British gum " or dextrine, a substance of most extensive eniployment for adhesive purposes. It can be purchased of many degrees of purity, but at its best is not available for photograpliic use on account of the imcertainty of its composition, and also the possibility of its containing deleterious substances introduced at the time of manufacture. Dextrine has been called terrified starch, and is, indeed, starch acted upon by heat, acydg, or diastase, the amount of real dextrine, if any, actually contained in a sample of British gum being an \indetermined quantity. Hence, looked at from all points of view, its use for any photographic work, at least where it would be brought into contact with silver compounds, should be deprecated ; of course, for carbon or platinotype pictures, its introduction, either as glaze or mountant, would be productive of no ill effect, and for ordinary adhesive purposes it possesses ixdvantages over both eum arabic and tragacanth. A little salicylic acid is recom- mended to be added to preserve it from mould. It may be interesting to give the formula for the use of dextrine as em- ployed by the United States Govornmsnt for coating postage stamps. It is made by mixing two parts (by weight) of dex- trine, one of acetic acid (free of water), and one of alcohol. When we come to discuss glues, the subject, so expands that very many pages of this Journal might easily be devoted to it ; hence a few leading points most likely to be of use will be named. If we put the question, " What is glue ? " a true answer would be very cumbrous, for it is not by any means a definite chemical compound, and its mechanical or physical aspects are as varied as possible. Briefly speaking, it is the dried jelly obtained by boiling certain animal substances in water for some time, and its colour varies from black when thick pieces are examined down to the patent straw. In the early days of the gelatine process, the use of glue or gelatine was hailed with acclamation as being a substance of so much more certain composition than pyroxyline ; but, when it is con- sidered that the jelly of which it is made is obtained from such widely different sources as we will specify in part, it would not be reasonable to expect constancy of chemical composition. Thus it is made from scraps of hides, tendons and intestines, tissues of bones, cartilages, horn, fishes swimming bladders, rabbit skins, parchment, old gloves, &c. When this jelly is required in the purest foi-m, it is extracted from specially pure materials specially prepared ; it is then dried, redissolved, and again chemically treated, and finally dried and put in form for the public. When it is required for dietetic or medical purposes the utmost care is taken, and the product is, when well selected, not at all likely to be injurious for any photographic purpose. At the time when there was more amateur gelatine plate-making than is now the case, most readers of the journals of the time had almost a surfeit of the properties of tlie various gelatines, British and foreign, and many brands grew to be well known. But at present the dry-plate makers may be presumed to know all about the matter, though there is no doubt of the advantage they gained from the discussions in the technical journals of the day. It was brought into prominence, for example, that the presence of a very minute quantity of grease had a very disturbing effect on the physical aspects of the film. It is not generally known that benzine and bisulphide of carbon are often employed in the preliminary treatment of bones before extract- ing tlie gelatine, so that all greasy matter is removed. Most samples of gelatine of good quality are free from this 308 THE BRITISH JOURNAL OF PH01OGRA.PHY. [May 10, 1893 fault, and, as such articles as this arenothiug if not practical, we may point out a few leading characteristics of a useful photo- graphic glue. First, let us say that chemicals— bleaching agents and mineral acids— at one stage or another are so largely used in the manufacture of glues, that, though glues of most excellent purity are obtainable, a sample of so-called gelatine is far more likely to be pure and trustworthy for photographic use. One of the most important characteristics is the melting point. For sensitive tissue and many photo-mechanical purposes a gelatine with a high-melting point is to be preferred. As ex- planatory, we may remark that an ounce of glue, for example, may require a certain amount of water, at, say, a hundred degrees Fahrenheit, before it will be a firm jelly, while another sample, with the same weight of gelatine and water, will keep liquid until it is reduced to perhaps sixty or seventy degrees. How to ascertain the suitability of a glue for this purpose would involve considerable loss of time, though a glue expert could perhaps give a valuable opinion from personal knowledge. The photographer paying a good price for a pure gelatine, is able to obtain what he requires in this direction simply by asking for it, at the same time ensuring freedom from injurious chemicals and from incipient decomposition so likely to be ruinous to a silver photograph of whatever sort. In conclusion, let us say that, whatever price is given, or whatever brand is bought, a sample first brought into use should be, at any rate, tested with litmus paper to ensure its neutrality, too many of the examples of modem fading being undoubtedly due to the use of acid gums and glues. Silver In Dry Plates.— Complaint is frequently made of the small amount of silver now put iu dry plates. But it is consoling to know, according to a wiiter in the JRenie May 10, 1893] THE BRITISH JOURNAL OF PHOTOGRAPHY. 300 pntionce of any sitter." Tlie continual prominence of colour photo- (rrapliy given by the lay press naturally leads the non-technical public to infer that photography in natural colours is mi fait accompli; hence so many applications to profe-ssional photographers for portraits by the new process in natural colours, ami the scepticism of the would-be sitter when they are told the thing is quite ioipossible. Tbe Bolipse Photogrraphs. — Highly successful as have been the two English expeditions, there now appears to have been a slight hitch in the photogi'aphic department of the one to the West Coast. Mr. A. Fowler says in a report that the English signal of the com- mencement of totality — the discharge of a pistol — wjis not given until ten seconds after the French one, which caused him " to lose three exposures during totality, and reduced the number of Sergeant Kearneys photographs from twelve to ten." In reply to this, Mr. T. E. Thorpe, in a letter to a daily contemporary a few days ago, says, although he did not hear the French sigiml himself, that another observer estimates it at two seconds only, and adds, " It is possible, therefore, that Mr. Fow-ler's estimate of ten seconds may not only have been erroneous, in consequence of the known difficulty of accurately estimating a time interval during the exciting conditions of an eclipse, but may also have arisen from the fact that the actual eclipse was shorter than the calculated one." It can readily be under- stood, with the months of preparation and anticipation, and the thousands of miles travelled to execute 243 seconds' — French calcula- tion two seconds less — work, that there would be some little excite- ment, subdued though it miglit be, during that brief period. The thing can be better imagined than described. EXHIBITION OF THE PHOTOGRAPHIC SOCIETY OF GREAT BRITAIN. The Exhibition of the Society for 1893 will be held in the Gallery of the Royal Society of Painters in Water Colours, 5a, Pall Mall East, London, S.W. The Exhibition will be inaugurated by a conrerxazione, open to mem- bers and their friends and exhibitors, at eight p.m., on Saturday evening, September 23. The Exhibition will remain open daily (Sundays excepted) from Monday, September 25, until Wednesday, November 15. Admission (from ten a.m. till five p.m.), one shilling. It will also be open on Monday, Wednesday, and Saturday evenings, when lantern slides will be shown ; admission (from seven to ten p.m.), sixpence. Members have free admission at any time. They may receive twenty day and ten evening tickets for their friends, and can purchase additional tickets at half-price. Members of affiliated Societies can purchase tickets at half-price of their respective Secretaries. Medals will be placed at the disposal of the .Judges for the artistic, scientific, and technical excellence of photographs, lantern slides, and transparencies, and for apparatus. The undermentioned gentlemen have been elected by the members of the Society to act as Judges, and have consented to serve : — Mr. P. H. Emerson, B.A., M.B. (Cantab), Colonel J. Gale, Messrs. F. HoUyer, F. M. Sntcliffe, and .T. B. B. Wellington. Scientific experts : Messrs. Chapman .Tones, F.I.C., F.C.S., and Andrew Pringle, F.R.M.S. The Judges will select the exhibits before the Hanging Committee begin their duties. Blank entry forms and any further information respecting the Exhi- bition, apparatus, and lantern slides, also nomination forms for member- ship, can be obtained from the Assistant Secretary, P. S. G. B. , 50, Great Russell-street, London, W.C. that, as iilbumen had stood the test of many years' experience, it was not well that an old friend should be discarded in favour of an inter- loper. Well, gelatine ha.s now pasted its novitiate, and has proved to bo all that we anticipated for it. We possess the Brst, or among the tirst, photographs that have been produced on this substance, and can attest their excellence as regards their unfading properties. As corroborative of this, we have just been shown the contents of a show-case which has teen exposed outside .a photographer's studio in Loughborough since May, 1802, and on which the light has been acting throughout the year, with such effect that the plush, originally of a maroon colour, which formed the background base on which the sj)ecimens were mounted, has entirely succumbed to the exposure except where covered by the prints — those known as " P. O. P.' These prints show not the slightest indication of having been affected by sun or weather, notwithstanding their fairly long exposure to this crucial test. INTENSIFICATION OF GELATINE PRINTS. Thk Photographisches Archiv suggests the intensification of gelatine prints by means of physical development. It is unimportant whether the prints have been toned or not, but it is necessary that all traces of the fixing agent should have been removed. Briefly, the prints may be intensified in the same way as gelatine negatives. A print on aristotype paper, fixed and dried, is placed in a solution containing hydroquinone, tartaric acid, and silver nitrate. The pro- portions of these substances can be varied without inconvenience, except that there should be a quantity of the acid sufficient to prevent any reaction between the hydroquinone and the silver. A few drops of ammonia are added to the solution to neutralise it. This will effect a slight deposition of silver on the image, which may be increased by the addition of more ammonia to the solution. Instead of hydroquinone other developing agents may be employed. It is essential that the print before the solution is applied should have its gelatine surface flooded with water, otherwise the silver has a tendency to be deposited in the gelatine on a powdery form instead of acting as an intensifier of the image. ARE GELATINO-CHLORIDE PRINTS PEKMA.NENT? Whkn gelatine was first proposed as a substitute for albumen in the preparation of printing-out paper, we said that on theoretical grounds there was no reason why gelatine should not be made to supersede the other entirely. On what grounds it was at one time stated that it woukl be likely to set up a decomposition of the silver image we never could learn, beyond that it was a mere surmise. We could better understand the good old conservative argument NOTES ON VARIOUS SUBJECTS. Black To>fES ox Rapid BnoMioK Papkb. The difiiculty mentioned by "A. J." in the last number, of getting as good blacks on rapid bromide paper as on slow, is one that I have experienced and surmounted, and therefore, perhaps, a few lines on the subject may not be out of place. Unlike Mr. Pike, who writes in your last issue, I have not made thou.sands of bromide prints and used hundreds of gallons of iron developer, but I have had a eood deal of practical experience of bromide printing, and it confirms me in the opinion that for development on the slow paper ferrous oxalate still has a future before it. "A. J." does not say the developer he employs with the rapid paper; but, assuming it to be ferrous oxalate, 1 find that by acidifying the potash and iron stock solutions with oxalic acid and .sulphuric acid respectively, instead of, as many recommend, acetic acid, the mildly restraining powers of which I have observed have a marked effect on greying the sJiadows, a slight improvement in the tone results. Again, I do not use an unnecessary quantity of solution, but, say, for a 12 X 10, about three ounces, as in my experience of both positive and negative work an excessive quantity of solution leads to loss of contrast. A hint as to exposure. If "A.J." uses the same light for the rapid paper as for the slow, let him diminish the volume of light by a stop rather than simply shorten the exposure, or, for contact work, let him double the distance between tlame and illuminant. For correct exposures I find the proportion of 3 : 1 answer perfectly. Some year or two back I experimented with ammonia-sulphate of iron as a substitute for the ferrous sulphate, and found that it assisted to produce tones of a deep velvety black without any tendency to greyness or rustiness. Of course, I am referring to a slow papr. If " A. J." is using amidol, hydroquinone, oreikonogen,or«uii.xture of the two latter (which I have used with great success), I would 310 THE BKITISH JOURNAL OF PHOTOGRAPHS. [May 19> 1893 recommend him to be as sparing as possible in the use of sulphite, the effect of a large quantity of which seems to me to produce images having a combination of three undesirable qualities— flatness, grey- ness, and hardness. Of the fixed alkalies, carbonate of soda in my hands promotes softness and a good colour, and a sparing use of bromide will prevent the greening of the black, as the Irishman would say, which can so often be traced to its use. Another plan of a remedial character for giving good blacks to bromide prints is that mentioned by you, namely, the immersion of the washed unfixed print in a combined toning and fixing bath. From practical isxperience I can endorse your recommendation to " A. J. to try this useful dodge. It is applicable to either slow or rapid bromide paper, and for those who like rich platinum-like pigment deposits (1 am one of those myself) I would recommend that for this purpose the fixing bath be permanently enriched by the addition of a little alkaline gold solution (y. s.). The Concentkic Lbns. I was interested at reading Mr. F. H. Burton's comments on the letter of Mr. W. J. Stillman, in which the latter gentleman states that, with the Concentric lens in his possession, he obtains as good definition with /-16 as with /-64. I, too, have one of the Concentric lenses, fitted with rotating stops from /-16 to /-S2, so that I am unable to speak as to the quality of definition with the small aperture with which Mr. Stillman's lens has been fitted, but in other respects my experience tallies very closely with that of Mr. Burton. Tho single object with which I should use /-16 would be for obtaining landscapes in which the acme of definition was not required. At that aperture I find the lens give a degree of sharpness which, to slightly traverse Mr. Burton's statement, would only spoil such negatives as those of maps, or of subjects with very fine lines. Mr. Burton appears to hint at having focussed with /-22 and exposed with /-IG. This, in my experience, would give no better definition than by focussing with, and using,/-16 alone, if as good. Indeed, I tested the point by practical trial, and was surprised at the extent at which the focus was altered. Like Mr. Burton, I am an unknown amateur, but I appreciate a lens giving a flat field, even illumination, and fine definition. To obtain such with the Concentric I follow one simple rule, which I recommend to others who have the lens, and that is, to neglect /-16 for critically sharp work, and focus tcith the stop you are yoing to expose by. The principal point Mr. Burton touched upon, namely, that the flatness of field of the Concentric enables the camera front to be lifted or lowered without impairing definition at the edges, is an important one, which should be noted by architectural photographers. A Suggested Backing Medium. The application of such a backing medium as a caramel mixture to 2lass plates, and, indeed, backing generally, involves more trouble than the ordinary amateur cares to expend. There is a species of ever moist rubber solution, I think it is, which, when spread upon a cardboard support, I have used for attaching large films to when exposing such in the camera, and it has occurred to me that possibly the use of such cards, coated with the rubber medium in question, might answer for the purpose, especially if it proved to be readily detachable from the glass. I presume j^erfect optical contact could be obtained. The coated cards, of course, could be used again and again. J. H. HoPwooD, Ph.D. IS THE PRESENT CONSTRUCTION OF PH0T0GR.4.PHIC STUDIOS WRONG IN PRINCIPLE ? [London and Provincial Photo^apbic AsBOciatlun.3 In the construction of photographic studios, whenever possible, the chief light is obtained from the north, and the studio is principally trlazed on the northern side : by this method direct sunlight is cut off from the sitter and steady illumination is obtained. Hence the light most used by photographers is that reflected by the particles floating in the air, for, if no particles were there to throw back the light of the sun, we should have the black sky sometimes witnessed in the Alps when the air is extremely dry, and then might almost as well use the light reflected by an unglazed blackboard. It is the same with the ea. Within a few miles of the shore we get different shades of green which grow clearer as the land is left behind ; but farther out the sea appears of a dark indigo colour, because of the scarcity of floating particles to reflect light to the eye. If, then. Professor Tyndall's plan be tried of puttmg a particle of large size into the sea, by flinging a white dinner plate overboard, that particle reflects green light to the eye as it sinks, and would do the same were it broken into myriads of smaller pieces. Before coming to the practical part of the subject, it is necessary to consider the nature of our reflecting screen in the northen* sky. The floating particles in the air of towns consist of minute drops of water, innumerable spores of small seeds, greasy coal smoke, frag- ments of dried horse dung, influenza and other germs, and dirt of endless varieties, including dust from meteoric stones rendered incan- descent by friction when entering our atmosphere at planetaiy velocities. These solid particles favour the precipitation^ of water, so also in a still greater degi-ee does the sulphurous acid given off from our coal fires. These aggregated varieties of floating dirt are to some extent rendered visible when a beam of sunshine is reflected by them, so as to mark its track when the beam enters a dark cellar through a hole in a shutter; we also see them floating in the light coming from the projection lenses of the magic lantern, and we swallow them wholesale with every breath of air which we take into our lungs. These dirty particles, then, form our reflecting screen in the sky to the north of the studio. Sometimes we get a better reflecting screen, consequently more light in the studio, when cumulus or other clouds in the north are illuminated by the sun. This improvement is but partial, because the clouds present also portions of their shadow sides, and do not cover the whole of the northern area in view. The question I now wish to raise among those present who know so much more about glass studios than myself, who am not the happy possessor of one of them, is whether it would not be better to abolish the floating dirt reflector and diffuser — to abolish even the floating cloud, and to provide a cloud of our own which shall be always there, which shall present to the eye no shadow worth mentioning, and shall be of a pure white. I mean a whitewashed wall, for experience with the lantern has already demonstrated that, as a dead-white reflector and diffuser of light, nothing excels common whitewash. Supposing these ideas to be correct, the result is that we shall have to build studios with a southern aspect, glazed high up on their southern sides. The accompanying diagram will shov,' what is in- tended, for verbal descriptions of mechanically constructed objects are hable to confuse both listeners and readers, unless illustrated by draw- ings to show exactly whac is meant. The suggested stuios will be high in proportion to their breadth ; for instance, let A B be the end of a little studio twelve feet wide, then the whitewashed wall, W B, say, of an adjoining building should per- haps be twenty -four feet high. The southern side of the studio is boarded up, except for special pur- poses, to a height, A K, of, say, ten to twelve feet all along the side, and the glazed portions are at K N \V. Thus, the rays of the sun entering ■" * '' the studio in the direction indicated by the arrows fall upon our artificial cloud or whitewashed wall, W B, which wall under the circumstances then gives the chief light for the illumination of the sitter at H. Into minor details it is not necessary to enter. Of course, the studio, as at present, will have to be boarded at the opposite ends, also along the roof, N W, and the side, N K, for a short distance from the ends. Bhnds for regulating the major light should be of neutral or dark tint, ancl movable along the face of the wall, W B : blinds also af the glazed portion of the studio will be necessary. Incidentally, it may be pointed out that, if A be a garden wall with a street on the southern side at R, that wall can be raised to K, and a good studio built at A B without enabling boys in the street to make remarks for the calming of the minds of the sitters, for street boys not being ten or twelve feet high in these latitudes will be unable to see into the studio. It would be diflicultto build upon the ground a good present- day studio if there were a brick wall and street to the south and a high house to the north. If the glazed roof had the pitch K W, the suggested studio of the future might do nearly as well, and would shoot off snow capitally. This kind of lighting might also he obtained ' ,.•■' N / ,.C K n o May 19. ISJI) THE BRITISH JOURNAL OF PHOTOGRAPHY. 311 by buiUin); a studio of the usual Noah's ark shape, and takinj? the chief working light from the whitewashed side of a dwelling-house to the north ; but. in the preferable lean-to studio pictured, a lower roof and a whit.'washed house-wall outside and above it would not give as good lighting, because the light from the outside wall woulil fall upon the glass roof at such a grazing angle as to be largely reflected off outside without enterin? the studio at all. The boarded side, K A, mi:;lit be made of largo sliding partitions, to be pushed back into the two ends of the studio, and then expose a glazed surface so as to take direct light in from the south upon those winter days during which the photographer is glad of any light he can get. Peradventure those portrait photographers, who hare taken special notice of the extent to which exposures are shortened when the northern sky is tilled with clouds illuminated by the sun, may be able to make some kind of guess as to the extent to which studios of the kind now suggested may expedite exposures, and lengthen the average photographic working day, remembering also that the white- washed wall presents a more uniform white surface than do masses of cloud. In the remarkable weather we have had for the last six ■weeks of almost unbroken sunshine, I have noticed that there have been scarcely anv bright clouds, at least within a circle of a mile or two of the Crystal Palace, for, being engaged in some new investigations in relation to gelatine emulsions, I have specially noticed the absence of clouds when I was frequently out of doors trying plates. Had portrait photographers had a white wall to the north", instead of the grey haze of an average cloudless London sky, they would have received even better light in the studio than during April last. Some comparative experiments on the light from a northern sky and the light from a northern whitewashed wall, made with the sensitometer of Mr. J. B. Spurge, of London, which is one of the most accurate standard instruments we possess in photoeraphy, would be exceedingly useful. They should extend over a considerable length of time, and be made under different conditions of weather and elevation of the sun. Having raised the major question before you — who know so much more practically about glass studios than myself — whether photo- graphic glass-houses should not be glazed on the south instead of the north, and have an artificial reflector and diffuser, it is not desirable to-night to go into minor details about studios. Many of those in existence are too short : there are reasons in portraiture as in land- scape work why more pleasing results can be obtained by using lenses of longer focus than those usually employed ; in fact, if a photographer had light enough, and a studio long enough, there is much to be said in favour of his using single combination lenses of long focus for portraiture. Supposing the studio to be built of glass and wood, there is much to be said in favour of malcing its walls and roof double with an air space between : it would be much warmer in winter and would economise fuel. Some studios are built in this way in St. Petersburg. There are considerable advantages in the use of iron instead of wooden frames for glaiing. The developing room should not be a small death- trap, but. when possible, a good-sized room in the adjoining dwelling- house, and fitted up as a laboratory. When, however, it is built as part of the studio, it should be a large room at the opposite end to that occupied by the sitter, and the door should so open that the camera can be used from inside the developing room, when it is de- sirable to place it at an exceptionally long distance from the person to be photographed. All these, however,are matters which have been previously publicly considered : but the major problem mooted in this paper is new so far as I know, and I have recently made some search into the Uterature relating to glass studios. In photography it is ■dangerous to say that anything is new, Whether the problem before us is or is not new matters little so long as in the discussion it brings forth from your stores of knowledge some information which will be useful to the photographer. W. II. Hahrison. PHOTOGUAPHY WITHOUT .\.N OBJECTIVE. The great advance which has taken place in the manufacture of sensitised films, and the enormous increase in their sensibility to light energy ha.s now brought photography without an objective within the sphere of practical work, and at this time it may prove interesting to note the real position of this method for obtaining photographic images. It will be found that the present literature on the subject is very meagre, and that the accounts of the experiments are so conflicting as to be unreliable. Experimenters have found that, with large a^iertures, some positions •of the sensitised recipient surface in the camera are better than others, and formula; nave been published, mi theories kave been (propounded, on account of this fact. The best known formula) are as follows : — Lord Rayleigh gives /=(■>,•-/■) where /is the least distance of good deflnition, r the radius of the aperture, -i the wave length of O = 0-(XXHJ17 inch. A Frenchman, Captain Colson, also derives a constant from a wave- length ; the constant is O'OOOSl on the metric scale, and his formula, d- = 0(M)8l F, where d is the diameter of the aperture and F the least distance of good definition. This formula means that nine- tenths of a millimetre aperture has the least distance of good deflnition at one metre distance.. J.- Mr, Dallmeyer gives the formula 6"= , where 6 is the least distance in inches for good definition, and ^ the wave-length 0=0-000017 inch, and r the radius of the aperture. Captain Abney gives 2 .Jl b, or, in other terms, the square root of the distance from the hole, multiplied by the constant 'OOS, gives the diameter in inches of the aperture which will give the best definition. The theory propounded by both Captain Colson and Captain Abney is the same ; viz., that the wave-phase from the edge first meets the wave from the centre of the aperture in equal phase at the focus ; the misfortune Ls, that the formulae based on that theory by these two gentlemen are not in accord, as the latter gives the focus about one- half that of the former. Another view held by some experimenters is, that if with larger apertures a shorter focus be taken than the one given by their formula, then each point of the object makes an image on the recipient surface, which has the same shape as the aperture. What I have found is as follows: — 1. All large apertures give soft pictures ; small apertures, sharp pictures, regardless of the focus employed. An aperture of one- thirtieth of an inch will give just as good a ])icture at thirty-two inches, at sixteen inches, at eight inches, at four inches, at two inches focus, and where discs appear in the negative they have much more to do with the illumination of the object than they have to do with the short focus, as they appear like cone shadows. An aperture of one- three-hundredth of an inch will give a sharp image at any focus. •2, The photographic energy passing tlirough an aperture is eight times gi-eater than passes through a lens having a stop the same size as the aperture. 3. The exposure required for ordinary plates can be worked out from the datum, that where the focus is sixty-four times the diameter of the aperture the time is one second. 4. The experimental evidence is rather in favour of there being an infinite number of foci through an aperture: but,if the large apertures have distinct foci, it almost follows that the small apertures must have the same. .5. Apertures above thiee-sLxteenths of an inch in diameter do not produce photographic images in a camera ; an aperture of one-eighth of an incn appears to be in the border-land between holes which will produce images and those which will not do so. (i. The distance of the object from the aperture does not appear to have any influence on the definition or the focus. The only theory which will embrace these experiments is the sup- position that when the light energy from the object grazes the edge of a suitable aperture, then the whole vibrations undergo a change of direction, because the edge of the hole becomes a new source of vibration. In otlier words, the infinite number of molecules on the edae of the aperture take up the vibrations, and they form new centres, from which the vibrations of the light are transmitted on to the recipient surface in the camera. It is not difficult to imagine the result which will follow this idea. The edge of the hole for all practical purpo.«es becomes the object, as it is imagined to be the source from wliich all ethereal vibrations emanate to the .sensitive plate. If the longe.st focus could be a.-cer- tained by direct experiment, it would follow as a consequence that another focus will be found at I, ^, j, i, and so on of that distanc-. As the number of axes of vibration are considered to be infinite, nii that account the number of foci may also be considered infinite. .\^ long distances the foci are remote one from the other, but as th^ distance between the plate and the aperture is approached, the foci become nearer and nearer to each other, until the point is reac'ie,! where the foci follow each other so closely as to escape observuii"' . If there is any truth in this theory, it is evident the value of :hi< method of photography must depend on the accuracy with whicli 1 1>.- edge of the hole is drilled and upon its perfect circular form. Here- tofore little care has been bestowed on apertures, and the designs "f most are faulty. For example, it would be almost impossible to get a perfect image through a cylindrical or conical hole, the liability if disturbances from otner surfaces or edges is too great. As our appliances for drilling holes is improved, the time may be reached when a perfectly circular aperture of one-thousandth of an inch 312 THE BRITISH JOURNAL OF PHOTOGRAPHY. [May 10, 189a may be made, and a hole that size would become the best optical contrivance for enlargements. The skilful use of apertures will enable artists to select any descrip- tion of texture for their subjects, and the skilful use of foci any system of illuminating the field of their pictures. To give a practical illustration of the views expressed in this paper, the writer has put in the market a quarter-plate camera fitted with two accurately drilled holes, the one aperture to give a soft picture on ordinary plates in one second, the other a sharp picture in sixteen seconds ; and yet the focus is only two inches for both apertures. The result of this contrivance is that now, instead of using a magazine eameia or dark slides, all that has to be done is to pack six, twelve, eighteen, or twenty-four cameras into a satchel, and to use a separate camera for each picture. The cameras are so light that nine cameras only weigh two pounds, and twelve cameras pack into the ordinary satchel for a camera. There is no machinery to go wrong, and the plates are in no way disturbed until they are fit to be developed in the dark room. The only requirement these cameras cannot yet fulfil is instantaneous pictures ; the time, however, may arise when plates are so sensitive that even instantaneous images will be within the reach of cameras without an objective. Arch"- C. Ponton. PRACTICAL REMARKS ON PHOTOGRAPHING DIFFICULT INTERIORS. Perhaps there is no class of subject that offers so many and widely different conditions in respect of photography as interiors, for be- tween the well-lighted drawing-room or public hall, and dark vault where little, and indeed it frequently happens, not a ray of daylight penetrates, there is a very wide difference indeed. The remarks which I am about to offer are the outcome of much close study and practical experience derived from an intimate associa- tion with the various classes of subjects I shall refer to, and embrace cases where it was only possible to use artificial light on account of the entire absence of light. One of the most commonly met with kind of interiors, especially on the part of amateur workers, is that of an ordinary drawing-room or other similar apartment in a private house. With many workers the photography of such is looked upon as an undertaking entailing little or no difficulty ; it is so easy to run the blinds to the top of the window, place the camera in the position that will enable the utmost amount of view to be embodied in the picture, expose long enough, and there you have it. In nearly nine cases out of ten these subjects are photographed without due regard being given to the best method of lighting the room. An idea prevails to a very large extent that it is necessary to flood the room with the utmost amount of light possible. Therefore the blinds are run up to their utmost extent, and the time of day selected when the greatest amount of direct light enters the apartment, there being no thought given to the employment of what is really theproper quality of light to employ. I do not wish it understood that I am in any way advocating the •employment of a poor or deficient quantify of fight ; quite the reverse. The more light any one can command, the better, but it must be of the proper quality, a.ni this, to a verv large extent, is a bright diffused light. A very interesting operation for any one desirous of experimenting in this class of photography is the following : — Arrange any well- lighted room, and expose a plate upon it with the blinds run up to the top, so that the utmost amount of light floods the apartment, develop, and print the result. Afterwards expose another plate, with this difference, that thin muslin blinds are hung over the entire window or windows, so that every ray of light entering the room passes through the muslin ; expose, develop, print, and mark the difference in the results obtained. It certainly will be instructive to any one who has not previously studied or become aware of the difference in results obtained by diffused light. _ In some cases it may be desirous to allow a short duration of direct light to enter the room during the exposure, so as to gain a certain amount of force in the high lights, but this is easily accomplished by capping and uncapping the lens, and removing the muslin from the window a short time previous to the conclusion of the exposure. The first efsential, however, is the employment of the proper quality wnd quantity of light. Another error frequently seen in this kind of work is the over- crowding of too many articles of furniture into the room. 1 of.en think were as much pains taken to see hoxo muvh could he done without as is generally taken to cram into the room, better results would be obtained. In this there is a very wide field for the exercise of good if indeed not artistic, taste, and it is a part of the undertaking that always enlists the attention of the ladies of a household, for they invariably like to be consulted in such matters. As a rule, however, I think it will be found they nearly all fall into this same error of crowding too many ornaments and other articles of furniture into the room ; this may not be so very noticeable to the eye at the time when photographing, but after the negative is printed it becomes more apparent in the picture, and then will be seen how much better it would have been had such and such an article not been here and there, and so forth, the result being, try again. Next to taking a picture of one's drawing-room, the amateur worker will be found to have a weakness for securing a picture of the interior of his church, and to a very great extent the remarks I have made regarding the employment of the proper quality of light will apply to this class of subject also, only with this difference, tliat it is almost impossible to resort to any means of acquiring an artificial diffusion of light, and hence exposures are made very probably with the sun's rays streaming through some of the windows, the results being by no means as good as they might be. Let any one carefully note the great difference in appearance which the interior of such a building as a church presents under the following aspects, viz., when no sun- light enters, but the sky is full of white fleecy clouds, and then note the change that suddenly arises when the sun shines strongly in through the windows. In the former case, with a bright, diffused sky lighting up the interior, every minute detail will be observed even in what is con- sidered the dark corners of the edifice; the moment, however, the sunlight comes streaming in, all this suddenly changes, the dark corners appear ten times darker, and muci that was noticeable to the eye before has now disappeared, and nothing but violent contrasts prevail. This is a state of matters that any one can easily see without much trouble, and it stands to reason therefore that sunlight should be avoided, and such times chosen for doing the work when the skv is full of bright, fleecy clouds ; and, should the sun come out during the exposure, the lens should be shut off by placing in the cap until it is obscured again with clouds. If we cannot in such eases assist matters by artificial diffusion, we can at least by the exercise of untiring patience bring to our aid Nature's own method of ditlusing light. In landscape and many other outdoor branches of photography sunlight is a siyie-qud non, but for interior work the photographers' sheet-anchor is undoubtedly a bright diffuse! light. Passing from such subjects as well-lighted rooms, churches, and public edifices, we are often brought face to face with interiors of a totally different kind, such as badly or indifferently lighted workshops, engine-shops, ships' cabins, and suchlike, where the amount of light at command is very small and gives no end of trouble. Quite recently I have taken a series of views of the interior of the magnificent new Atlantic arreyhound, the Campania, and can speak from experience of the difficulty attending the getting of good results in confined and cramped positions, and in many instances where the subjects are lighted by means of port lights only. Nevertheless, by the exercise of thought and patience, much that at first sight appears an almost insurmountable difficulty will to a great extent be overcome. In engine shops there is generally a need for some preliminary arrangements being made so as to secure the best results. These, most likely, will embrace the covering up of some unwelcome window, and in other cases the colouring of some parts of the machinery with a suitable tint, also the toning down of any very bright portions of the engine or machine that is being photographed. Although, in one sense, machinery does not come under the category of interior work, still in numerous cases operators are called upon to photograph engines, machine-", and other heavy portions of work in the positions thev occupy before being taken to pieces or removed. In cases where such are placed in close proximity to a large window or sliding door, a very great difference will be exneriencd in the time of expo-ure neces.sarv as against the time taken of an entire interior. I have known oa^es where the whole interior required a day's exposure, and a machin-* placed somewhat close to a large side window of the shop was well exposed in ten minutes. There is a very wide rantre for thought in this kind of work, and a practi al experience of this class of photography is of great value, differing as it does in a great measure from ordinary studio work. From badly lighted interiors to interiors where no daylight enters at all is the next step down the ladder, and in this class of work may be mentioned bonded stores, warehouses situnted under railway arches, underground workings, &c. T. N. Ahmsteo.no. .May 19, 1893] THE BRITISH JODRNAL OF PHOTOGRAPHY. 313 SELECTIONS. [Holborn Camera Clnb.] The title I have chosen for my paper seems to me to permit a little wandering abont from subject to subject, without inferring an obligation to limit myself to any particular thing, or to bore you by harping on some process or other that would of necessity bo more or less stale. My first selection is to touch on the errors of omission and com- mission often indulged in by photographers, not from the lofty -stand- point of assumed perfection, but rather from that of one who has muddled and messed about in the sloughs of photographic despair, sometimes getting out, but sometimes sticking fast until the friendly help of a brother photographer has landed him on solid ground. There s no disputing that most of us arc, or fancy we are, artistically inclined, or we should not select photography for a hobby, an amusement in which genuine success chieily depends on artistic ability. Whether we become successful photographers or not is determined by the amount of scrupulous attention we give to trifling details, iiiiided by artistic iii-^tinct, or whether we look at the thins^ as only an interesting mechanico- •chemical process, whose ultimate result i-i a so-called pretty-looking negative. There is a gulf between the two ultimates too wide to be bridged over. Just recently an energetic controversialist has denied our right to the ■name of artist, and repudiates in big letters the very idea of photography ■being an art, fine or otherwise. For the sake of argument, we will lassume that photography is an art, and that any of us who succeed in making good pictures, however artfully, are artists. This brings me to talk about the things we do, and those we leave undone in this con- nexion. Since I had the pleasure of last addressing you, I have had the opportunity of seeing much photography by those who take it up for amusement rather than profit, and must confess I am surprised at the small percentage of those who make the best of their negatives. JuDicioi's Doctoring of Negatives. Many very clever manipulators are content to print their negatives jutt as tliey come, and it is not till one puts the finger on such-and-such ■effects, and asks, " ^Vhy this ? " that they perceive there might be some improvement in the direction indicated. The two most striking delin- ■quencies are under-exposure and blank spaces, where there ought to be clouds. The universal desire for rapidity in securing representations of moving objects induces under-exposure and all the evils that follow in its train. An under-exposed neiiative will never make a perfect print, although very often much better results might be secured by judicious doctoring than by printing the negative in its untouched condition. Of the various methods of doing so, some are as follows :— In the first place, make a rough print (which, by the bye, is a much better guide than the negative itself, which is apt to give wrong ideas of its printing capacity), and notice especially those parts in which increased or reduced density would be an improvement, or where masses of shade are broken up by small points of light that would be much better absent. The method to be chosen for treatment depends entirely on the sub- ject. The proof may show that the high lights throiighottt are a little too dense ; this indicates treatment with a weak reducing agent in the bath form, or too weak, requiring additional density, or it may show only portions that would be better for reduction, made by local action chemically or mechanically by rubbing down with spirit. The objection- able points of light may be removed by a sharp-pointed knife. We now cover the back of the negative with tracing paper — " papier mineral " is the best— cutting away the paper over the too dense portions, and work- ing on the darker parts with lead pencil, and strengthening .the. lights on them where it would be an advantage— sometimes merely rubbing a little black lead over front or back with the finger's end— will be found useful to generally reduce a shadow. I have now alluded to some of the different means in general use for improving a negative. An apparently good negative might not probably require all this doing to it, but one or other of the plans might effect an improvement on nearly all the negatives that are made. Sometimes a mere touch or two of pencil on the highest lights on the film side will make a considerable addition to the brilliancy and scalj of tone in the picture, and sometimes covering up one part, whilst another continues printing, will woik wonders. A Word on Two about Papeijs. Now a word or two about papers. I find negatives that are nnexcep- tionally good for albamen-paper printmg much too strong for the best results on the gelatino-chloride papers, that seem to be fast oupeiseding our old acquaintance, albumen. Of what kind a negative should he as regards density ii undoubtedly regulated by the surface upon which it is intended to print it. With th-) pelatino-chloride papers onr old-fashioned ideas of a good negative seem to bo somewhat np«et, a very much flatt«r, thinner cUcIik being required. One that with ordinary silver printing on albumen paper wonld only produce a poor, insipid result seems to be most suitable. With gelatine dry plates there is, undoubtedly, a large percentage of flat, muddy-looking negatives made, quite useless for producing good results by the old processes, but with the new they make excellent pictures. The print I now pass round was from a flat, over-expo^ed-looking nega- tive, and one I should certainly have discarded for albnmen-paper print- ing, but which comes out very fair on the gelatine paper, so much so that the question is. Ought we to make our negatives to suit the new paper as a regular thing, and at once and for all give up the standard of "wet-plate negative" as the ne plus ultra of perfection? At any rate gelatine paper puts pretty negatives at a discount. If no particular faults develop in this kind of paper by keeping (and I see no reason why there should), we may congratulate ourselves on a very valuable addition to our material, as by its means we certainly secure a better exposition of the delicate detail of a negative than was possible with the best albumenised paper, unless it was enamelled with collodion and gelatine afterwards, and even there I think the new paper has an advantage. I have experi- enced some little difficulty in mounting the prints when a fairly large batch has to be dealt with. I, possibly, have not found the best way of sotting about it, not having had much practice with this class of paper. With all the collodion-surfaced papers I have tried there is considerable trouble to manipulate; their curling propensities, when wetted, are simply abominable. They may, however, vary somewhat, according to their manu- facture. Perhaps they do, but the samples I happen to have tried as soon as they are wetted turn from prints into cylinders, and keep so unless forcibly held open, so that toning or working with any degree of satisfac- tion is out of the question. A good collodio-chloride print should, I imagine, be most permanent, if we may hazard an opinion from the behaviour of other collodion surfaces, although from time to time doubts have been expressed to the contrary. Gelatine papers do not curl, but suffer all the treatment of toning, fixing, and washing with the greatest pliability. Whether an abnormally hot summer will introduce diffi- culties remains to be proved. Spectacle Lenses. The last time I had the pleasure of addressing you, the topic was, I believe, on spectacle lenses as used for photography. Since then I have constructed several other combinations of varying foci, and really, for all ordinary work not necessitating rapidity, nothing could be better. Depth of definition, rectilinearity of lines, and covering power seem, as far as I can judge, equal to any orthodox lens. In spectacle combinations intended for wide-angle work I fancy there is less apparent distortion than in the orthodox form. Why I cannot say. Take, for example, cylindrical objects ; there seems to be less disposition to the oval form if situated at the margin of the plate ; not that it is quite absent, but that there is less of it ; also, objects in the near foreground and near to the lens are not rendered so large in proportion to the rest of the picture. These prints I pass round will illustrate my meaning. In the interiors the nearest objects shown were not more than five measured feet away from the lens, and in the church view the tomb in the foreground was about nine or ten feet away. Now, with an ordinary wide-angle lens in the same position, I fancy the perspective would appear much more violent, also the lines forming the upper angle of the tower would be more acute, for the camera was tilted, the lens pushed up high as it would go, and swing back used. Still, with all this, the picture has to me more the effect of being taken with a narrow-angle lens removed to a greater distance. This, I must confess, is not at all a scientific or convincing method of argument; but, as I had no other lens at hand to test the accuracy of my impres- sions, I give you them for wliat they are worth. The combination was five and a half inches focus on a whole plate, with a stop one-sixteenth of an inch in diameter, so you can draw your-own conclusions. The exposure was about ten or twelve seconds ; but, in the matter of exposures, I am somewhat of an impressionist, that is, I trust to judg- ment rather than giving a definite number of seconds, for, with regard to outdoor work, with all its varying lights, I often do not quite decide abont an exposure until it is actually taking place, and then may elect to slightly lengthen or curtail my previous judgment, according to circum- stances. 1 have found a one-sixteenth of an inch stop the best working step for all combinations of spectacle lenses, although, with the long-focus ones, a tenth of an inch is useful. Twelve inches focus and one-sixteenth stop mikes the working aperture /-Mt2. This seems as if it would necessitate very long exposure, but in reality ten teoonds on an llford ordinary plate is ample time in a fair light. The t«o Thames- tiJe vidws I pass round weie taken under pueh conditions; in fact, less time would have done, as I foand they diJ not rs'iuire the full amount of 314 THE BRITISH JOURNAL OF PHOTOGRAPHY. [May 19, 1893 alkali to bring them up to printing strength, and they developed rapidly, indicating that with a normal developer they would have been over-exposed. The advantage of the small stop is getting beautiful defi- mition all over the plate, and, when an exposure is required of more than one or two seconds, it matters, I think, very little if it is ten or twenty. In the old collodion days half a minute was considered an average exposure on an ordinary landscape, such as these are, and it was often very much longer, and even then not considered very protracted. I =am aware that many think the use of an exceptionally small stop preju- dicial to atmospheric effect, an opinion I cannot altogether endorse, as. ynth a proportionate exposure, I have in this respect found no falling off, and I quite believe atmosphere and definition may go hand in hand. Where it does not, I think the fault may be fairly attributed to under- •exposure. ^dwabd Dunmobe. {To he concluded.) PHYSICAL DEVELOPMENT. The substitution of bromide of silver -ivithout free nitrate of silver, and the consequent development of the image from the haloid itself for iodide, or bromo-iodide of silver with free silver nitrate as the sensitive material, along -with its accompaniment of development of the latent imajre, not from the haloid, but from the extraneous silver nitrate, was undoubtedly the especial point of change when about twenty-tive years ago the wet-collodion process was gradually dis- ■placed" by the drv-plate process. In the wet-coliodion process, as well as in Daguerreotype, the silver deposit which constituted the developed image was not the product ■of a chemical reaction, as is the case in modern photography by the use of alkaline developers, but originated by a peculiar physical property of the latent image, called photographic attraction. The developing agent— in the wet-collodion process the free silver, and in Daguerreotype the mercury vapour— formed a compound with the reduction product and not with the unaltered haloid, without altering the chemical constitution of the former. But, even in one of the modern photographic processes, the develop- ment of faintly printed gelatino-chloride printing-out paper, this old method of physical or molecular development plays a part. In this process, as well as in the collodio-iodide process, the sensitive film itself contains the soluble silver salt, which in contact with the exposed «ilver haloid is reduced by the developer. It may, however, be equally well added to the developer, especially if the silver salt of the sensitive film has been exhausted, as, for instance, in the process of intensifying collodio-iodide plates with silver. If any other suitable sensitiser is added to the sensitive film, as in the case of the iodide of silver dry process, the silver nitrate needs to be employed only in the developer. It is intended by the following lines to draw the attention of the readers to a number of interesting applications of physical develop- ment, which, after veiy careful and extensive experiments, have been described of late by Herr R. Ed. Liesegang, in the Pkotoyraphiache Jirchiv : — 1. The Emplotjment of Oallate of Silver in the Process of Developing Gelatino-chloride Printiuff-out Paper. — In developing gelatino-chloride printing-out paper the excessive silver nitrate can be removed from the film by washing, when a mixture of the developer, which may eventually be acidified, with the former can be employed. Upon this observation the following method, described by Herr Liesegang, is based : If faintly exposed aristotype paper is freed from the excessive silver nitrate, and from other soluble compounds by washing in several changes of water, the image printed on it will develop in a ■concentrated aqueous solution of gallic acid to which a slight quantity of silver nitrate has been added, equally well as on paper of the same ikind which is developed without wasliing in plain gallic acid. Whilst, however, in the ca.se of the latter method the prints are reddish-brown 'before fixing, the washed prints will become intensely black by ■development in the gallate of silver solution. Over the older method, with plain gallic acid, thi^t new one bus the advantage, that the deposit formed in the developing solution is considerably flighter. lyiixtures of sliglitly acidified hydro([uinone, pyrogaliic acid, and of •other organic developers with silver nitrate will act in a ^like manner. 2. Acid lJeielo]]er8 fur (Selatino-hromide. — Though, in the gelatino- tromide dry process, the chemical developing method has been ex- clusively used hitherto, the exposed gelatino-bromide film may also be treated with a physical developer, if either a mixture of silver 'nitrate with a developer, which may eventually be acidified, is used, •or if the plate is treated at first with silver nitrate, and then, without washing previously, with the developer. If a normally exposed gelatino-bromide plate is placed in a mixture of — Hydroquinone (2 per cent, alcoholic solution) . . •") C.c. Formic acid "^ » Water • 50 „ Silver nitrate (5 per cent, solution) 5 „ a faint yellowish-brown image will be obtained after eighty minutes. The developing solution remains perfectly clear. To obtain negatives of sufficient density it will be necessary to expose the plates from three to four times longer than those to be treated with a chemical developer. If in the above formula the acid is omitted, a reduction of the silver salt of the liquid soon takes place. As mentioned above, a similar result may be obtained if the plate is at first placed in the five per cent, silver nitrate solution, and then, without washing, in the developer. In the case of taking a one-half per cent, hydroquinone solution as the latter, a brownish-red image will appear after about half a minute, but afterwards a metallic powder is precipitated, which, however, does not in the least adhere to the film of the plate. If acetate of soda is added to the hydro- quinone solution, red fog will be produced. Silver nitrate mixed with metol very soon gives an olive-brown image, whilst, if mixed with para-amidophenol, a yellowish-brown image is produced, development being, however, slower. Gallic acid with silver nitrate does not at all develop, and with amidol at once red staining of the film is pro- duced, together with a considerable precipitate in the liquid. :3. Developing the Plates after Fixing.— It a gelatino-bromide film which has been exposed to light is fixed, the sub-bromide of sdver is very likely decomposed to bromide and metallic silver: but, in a normally exposed gelatine film, the contents of metallic silver are so slight that, after fixing, not the least darkening at the exposed parts will be visible. With nascent silver the molecules may, however, be rendered considerably larger, and the image becomes then visible. _ If a gelatino-bromide plate which has been normally exposed w the camera is placed in a solution of hyposulphite of soda and, after fixing and well washing, treated at first with a ten per cent, solution of silver nitrate, then, without washing, with a developer consisting of hydroquinone and sodium acetate, a blue to bluish-violet image of slight intensity will be developed in the latter solution. The process after fixing mav be carried on at daylight. I'ara-amidophenol, metol, or pyrogaliic acid, may be substituted for the hydroquinone developer, or silver nitrate and hydroquinone may be mixed to a single bath if the latter be slightly acidified. 4. Intensfi/inij Negatives hy Acid Development .—Ji a sensitive him which has been exposed in the camera is treated with nascent silver, the latter is precipitated not only on the exposed silver haloid but also on finely divided metallic silver in absence of halogen silver. For this reason it will be possible to intensify a gelatine negative with a physical developer by separate treatment witli silver nitrate and gallic acid, or hydroquinone, &o. The separate employment of silver nitrate and developer has the advantage over a mixture of the two, that in the case of the former substances may be added by which the keeping qualities of the developer are improved, for instance, sodium 'sulphite, and also substances by which the process is accelerated, for instance, sodium acetate. The following method has been used by Herr Liesegang:— , , j , , j The gelatine negative is very thoroughly washed and then placed in a five to ten per cent, silver nitrate sollition. After a few_ minutes it is tran-sferred, without washing previously, in a diluted mixture of hydroquinone with sodium acetate, known as " aristogen :"— Hydroquinone (" per cent, alcoholic solution). . 4 c.c. Sodium acetate (15 per cent, solution) -8 „ Water 60 „ and allowed to remain until it has acquired the desired density. It it well to place it finally in a solution of hypo. Other organic deve- lopers, in plain solutions or mixed with sodium acetate, maybe sub- stituted for the above hydroquinone developer. The intensihcation which may be obtained by tliis method is said not to be as consider- able as with bromide of copper and silver nitrate. 6. Intensifying Fi.ied Pnn''.<.— According to the same principle as described sub i, also fixed prints on various printing-out papers may be intensified after fixing by physical development. It makes no difference wlietlier they have" been toned or not : but it is, of course, necessary to wa.sh the'm previously verv thoroughly, ■•^ince the least trace of hypo in the film causes yellow" fog. The following experi- ment has been made by Herr Liesegang :— A finished print on aristotype paper was placed in an aqueous solu- tion of hydroquinone, citric" acid, and silver nitrate. The t^opor- tonsof these substances are of no importance; however, a suthcient May 10, 1893] THE BRITISH JOURNAL OF PHOTOGRAPHY. .'{15 Quantitv of acid sliould bo presont, to prevent the reaction betwoon she hyciroquinone and tho silver salt. At first no intensification of the print took place, on account of the fact that no precipitate of silver was produced in the liquid ; but, as soon as a few drops of ammonia were added, so as to render tho bath just neutral, a slight precipitate of silver was formed, and, at the same time, intensifica- tion of tho image took place. If the latter was not sufficient, a few drops more of ammonia were added. In this way the prints may be strengthened to any degree. For hydroquinone all the other silver intensifiers may bo "substituted. It is necessary that previouslv to the above treatment the prints, especially those on gelatine-emulsion papers, should be well soaked in water, in order to prevent the silver deposit adhering to the film. In adding tho liquid ammonia, care should be taken that it does not drop directly on tho print, because it would otherwise produce yellow spots. 0. The Application of I'ltyiical Development, to Various Other Surfttce.f. — I*"rom the experiment described sub 5, it will be seen that not only tlie silver molecules have the property to attract the nascent silver of the developing liquid, for in the case of a toned and fixed print, which therefore contains no more silver haloid, the gold has the same function as the silver. In like manner, in a freshly prepared mixture of silver nitrate with a suitable developer a purely physical intensification will take place : — (a.) Of finished chloride of silver positives in which gold, platinum, osmium, iridium, and other precious metals have been substituted for silver. (6.) Of nnished platinotype prints, carbon prints, Woodbnrytypes, of prints obtained by the powder process, and of similar prints, pro- vided that no greasy substance has been employed in combination with the pigment, as in collotypes, letterpress prints, &c. (c.) On glass, celluloid, ebonite, and on several other substances the silver is deposited, if they have previously been freed from the gas' or water atmosphere condensed on them. 7. Intensifying Finished Platinufi/pes. — As mentioned above, mh fi b, tinished platinum prints may be sutcessfully intensified by the application of physical development. The print, after being wetted with water, is placed in a mixture of— Aristogen (see above, sjib 4) 10 parts. Citric acid (2 per cent, solution^ 5 „ Water 130 „ to which, just before use, ten parts of a five per cent, nitrate solu- tion have been added. After a few minutes finely divided metallic silver will be precipitated in the liquid, which, however, does not alter the qualities of the bath. The platinotype will very soon gain in density, and at the same time it turns intensely brownish-red, the whites remaining perfectly clear. The precipitate of the bath will adhere to tlie paper only in cases where the print has not pre- viously been moistened with water. Afterwards the print is treated either with hypo or with any combined toning and fixing bath. In fixing, the brownish-red tone of the print is preserved, though it wQl be reduced to some degree. With the toning and fixing bath the colour of platinum is nearly obtained. Instead of aristogen, para- amidophenol, pyrogallic acid, metol, and other developers may be em- ploved, if they are previously rather strongly acidified. With pyro- gallic acid the black silver modification will be obtained in place of the brownish-red one. 8. Siheriny Glass. — By aid of a quite freshly prepared, still per- fectly clear mixture of slightly acidified pyrogallic acid, or of para- amidophenol, aristogen, &c.,with silver nitrate the silvering of glass is a matter of great simpUcity, provided that the surface has been pre- viously freed from the adhering gas or water atmosphere by rubbing it vigorously with alcohol or ether. Tlie glass surface will then be covered in a few minutes with a thin layer of tightly adhering silver. Should the thickness of layer be not sufficient, pyrogallic acid or para- amidophenol, aristogen, &c., respectively, and then silver nitrate solution should be added alternatively. The experiment will be still more successful if the glass surface is at first poured over with the con- centrated alcoholic aristogen solution, as it is sold by the manufacturers, and then, after the excessive liquid has been allowed to drain, placed in a diluted aqueous solution of silver nitrate. For the aristogen strong alcoholic solutions of other developers may be employed. The silver deposit is produced within a few minutes. The glass may be equally well silvered if it is at first moistened with an alcoholic solution of silver nitrate, and then placed in a diluted developer; for instance, in aristogen 1 part, water 12 parts. The operation, as a rule, must be repeated in order to obtain a sufficiently intensive deposit. In conclusion, it may be mentioned that Herr R. Ed. Liesegang gives the following explanation with regard to the action of the physical developers :— Soon after the pyrogallic acid, or the para-amido- phenol, metol, &c., has been mixed with the silver nitrate, the silver IS suspended in the liquid in the finest state of division. The result is not a solution as it is generally understood, but a kind of emulsion. The portion of the liquid which encloses the single particles wUl, however, not be able to perfectly separate the silver molecules, the power of the latter for uniting themselves being greater than the adherence with the liquid atmosphere. Consequently, the silver particles unite to form larger particles. Hkbua.vn Schnausb. A KEW TELE-PHOTO LENS. OcB attention has been specially drawn to a new lens of the " tele-photo " (lennx just received by Messrs. George Houghton & Sons, 99, HigH Holborn, W.C, and we have before us quite a number of views that have been taken by its agency. Having been afforded an opportunity of examining the lens in question, we are enabled to give the following description, aided by the drawing underneath. wosswtmw^ TELE-OBJECTIF PANORTHOSCOPIQUE — PARIS — U' In the first place, there is what seems to us a well-made "rapid rectilinear," eight inches in focus, fitted with iris diaphragm, and which, when unscrewed and used alone, fits the flange, A, of the tele-photo system screwed on the camera front. This lens covers a half-plate to the corners, judging from a specimen of its work sent us. When screwed into the outer flange, C, of the tube (which is four inches long), carrying at its nearer end that which is next the camera, the tele-photo system is now complete. The image on thelfocussing screen is seen magnified up to eight times ; but, by operating a rack and pinion, the concave lens B, can be brought nearer to or farther from the rectilinear lens in front, and can thereby be made to increase or diminish the telescopic effect to the desired extent. In the views submitted to show its various powers, there is, first, a print from a negative by the rapid rectilinear alone, and this, we may say, leaves nothing to be desired as] regards definition. We have next four other photographs, taken from exactly the same standpoint, showing degrees of enlargement, respectively three, four, five, and six times that of the primary picture. These, as they ascend in magnifying power, show a corresponding increase of detail, ornamental ironwork which is merely suggested by the original lens now showing its pattern, with very desirable distinctness ; while distant trees, still more feebly suggested in the primary picture, are shown individualised in the tele-photo ones. An engraved scale on the sliding tube which is actuated by the rack and pinion permits one to see at a glance to what extent tlie camera has to be extended in order to produce the degree of magnification that is to be adopted in any special case, and thi3,tin our opinion, is a great con- venience. The lenses, of Parisian make, are by the house of Clement A Gilmer (late Laverne), whose reputation is good. The concave lens, which acts such an important part in tele-photo combinations, is of the same diameter as those forming the rapid rectilinear. It is a crossed doable concave, the deepest curve being to the front, the surface to the back being concave in only a slight degree. They are all said to be formed of .Jena glass, and the price (5/. ai. ), which includes the rapid rectilinear, will be considered strictly moderate. To magnify three times, the camera requires racking out six and a half inches ; six times necessitates sixteen inches, and so on, according to the indications on the scale. Messrs. Houghton & Sons supply the trade and the public in this, country. 316 THE BRITISH JOURNAL OF PHOTOGRAPHY. [May 19, 1893 BIRMINGHAM PHOTOGRAPHIC SOCIETY'S EXHIBITION. This Society held its annual Exhibition last week, nearly 400 exhibits being shown. ,, „,.„. t, i t In instantaneous work the silver medal fell to Mr. William Rooke for a Christiania street scene, and Mr. J. P. Heaton, Mr. H. W. Southall, and Mr T Taylor (Staffordshire) received honourable mention. Mr. J. Simkins was the medallist, and Mr. J. H. B. Manly is honourably men- tioned for cloud photographs. For landscapes Mr. H. W. Southall carried off the chief award with a clever little bit of work— C/ia<«)ur)/ MM. Mr. W. Jones was the medalUst for enlargements. For portraiture the silver cup went to Mr. Leeson. Mr. J. Simkins was the medalhst for interior work, his exhibit being the tomb of SirFulke Greville, in Aloester Church, honourable mention falling to two productions of Mr. G. F. Lyndon and to one of Mr. W. T. Greatbach. Mr. Simkins was again the medalhst for exterior architectural work with a view of the Chapter House, Much Venlock. He was also honourably mentioned, as was Mr. C. J. Fowler, who also obtained the chief award in oenre work, Mr. Southall being also mentioned. In hand-camera work there were only three exhibitors, con- sequently there was no award. In the seascape exhibits Mr. A. J. Leeson ©ur lElJitorial STatle. The Mabtial Annals of the City of Yobk. Bj the Rev. Cassar Caine, F E.G.S. London ; Cbas. J. Clark, 4, Linoolu's-inn-flelds. As a former A. C. to ILM. troops, York Garrison, the author has had exceptional opportunities for qualifying himself for the task he has undertaken, and -which has culminated in this work. The Eboracum of the Romans, York can boast of having been the residence of a Roman Emperor, Severus, in a.d. t'08, having dwelt here while hi.v troops were constructing the great wall of defence across the island. Foi a long period York was the capital of this country, and it, or its vicinity, was the scene of several battles. It is gratifying to find that a historian of Mr. Caine's abilities and powers of research has under- taken to give in a single volume the succinct and methodically arranged account of this ancient city, its martial annals, and inci- dentally its antiquities. It is to be regrett^id that the temples. was the medallist. Mr. M. H. Chubb was the successful exhibitor both in the champion class and in that for three prints, any subjects, any size. Mr. T. Taylor took the bronze medal for the third award in the champion class, the second not being allotted, while Mr. H. C. Manton took the corresponding prize in the class for any three prints, Messrs. W. S. Aston and C. H. Barnsley being honourably mentioned. Mr. William Booke took the silver medal in the section for photographs not included in the above classes, with a hoar-frost picture ; Messrs. J. Simkins, P. T. Deakin, and W. Topham were mentioned. Mr. H. AY. Southall was the medallist for bromide prints, with a view of the Avon at Cropthome. Mr. E. C. Middleton was successful in the class in the survey section for three doorways in Warwickshire, and Mr. E. Underwood, who alone seems to have understood the object of the class, the medalUst for a nonagenarian in Warwickshire Peasantry. The last-named gentleman was also success- ful in another open class in the survey section, while Mr. Middleton obtained a second medal for a view of Stretton-on-Fosse, in Characteristic Villai/e .Si-enes. The medal for church windows was not awarded. Mr. .7. H. Piokard received the medal and two (the only) honourable mentions in the class for architectural details. Mr. E. C. Middleton added one more to his successes by securing the medal for lantern slides. The summer season of the Polytechnic School of Photography will include a series of lectures by Mr. Horsley Hinton, Mr. Charles W. Gamble, Mr. E. Howard Farmer, and Mr. Gamble, particulars of which will be found in our advertisement columns. We are pleased to find the Polytechnic is so popular as an agency for diffusing a knowledge of photography. palaces, theatres, and similar publio buildings with which the Romans adorned their cities, have long ago disappeared, but one cannot take even a brief walk through this city without realising that he is still in the presence of antiquity. As a clever and discriminating photo- grapher, Mr. Caine has most copiously illustrated his book with the archseological remains, for the possession of which the ancient city enjoys a proud pre-eminence over every other town andciiyin this country; and in one or other of the sixty illustrations which embellish the booif we have tbe most of them. Many of the bars or gates through which the city was entered are imposing structures, and make good pictures. This is especially true of Micklegate Bar and Monk Bar, which present the appearance of high towers on the city walls, for York is one of the few walled cities now remaining in this country. In addition to the various bars, Mr. Caine has laid under contribution all the other subjects of interest, such as the Multangular Tower, St. Mary's Abbey, Stamford Bridge, Clifford's Tower, and the Old Baile, the Red Tower, St. Mary's Tower, Marston Moor, Fisher- gate Postern, &c. Of these Bootham Bar is perhaps not the least in- teresting, on account of the fine view of the Minster seen in the back- ground. Of these various illustrations we here present an example, ' the Manor House of King Henry the Eighth, in which Charles the First resided for a brief period in 1639, a few years before the battle of Marston Moor, so disastrous to this king. The work is ^ classified into periods, opening witli the Roman Period, from a.d. oO to A.D. 426, terminating with the Hanoverian Period, from a.d. 1711. May li', IfsSa] THE BRITISH JOURNAL OF PHOTOGRAPHY. 817 AMATKI'b's DkVKLOI'ING and To.Vl.Vfi OfTKITS. Mbssks. Ai^thuu ScHWAnz & Co., of Dashwood Houso, E.G., are ecndinf; out sets of Dr. Andrt'sen's developing:, fixiiifi:, and toning cartridires, -which should bo handy for travellers and amateurs. The boxes include metol cartridges, the contents of which being dissolved in water form the developer : fixing cartridges: and toning and fixing cartridges for use with either albumen or chloride papers. Wo have before spoken of the excellence of these preparations, which in this form will, no doubt, be welcome to many. Thk Dai.u^stypk Shakespbabe. Dnncan C. Dallas, 5, Fumival-stieet. Of the Dallostype Shakespeare, which is a photographic reproduction of the famous first folio (IG'-i'J) edition, the complete play of T/ic Temjiefl has just been published. \Ve have before commended the excellence of the reproduction, which, when complete, should be much appreciated by lovers of the national bard. We understand that Mr. Walter Cmne' is preparing a number of illustrations for the series, which should make it additionally valuable. Thb STurio. 16, Henrietta-street, Covcnt Garden, W.O. Monthly, price Qd. This, the first number of a monthly magazine to be devoted to fine and applied art, is beautifully got up, printed and illustrated, the latter being charmingly unconventional, and, in some cases, highly original in style. Among the illustrated articles are : " Sir Fredericlv Leighton as a Modeller," " The Growth of Recent Art," " Spitallields' Brocades," by Mr. Liberty, and "A new Illustrator— Aubrey Beardsley," whose pecuUarly original style affords Mr. Joseph Pennell material for a laudatory article. Mr. I'ennell says : " The criticism of art to-day is merely the individual expression of persons who mostly know nothing about their subject." His own article is purely critical. The Lombehg Dry Plates. E. Stiepel & Co., 80, Bishopsgate-street Within. .Samples of the " Lomberg " dry plates having been submitted to us for trial, we find them of medium rapidity, yielding, with normal pyro-soda development, images of good quality, cleanness, and density. Their rapiditv, according to Watkins' system of speed measurement, is 80°. RECENT PATENTS. APPLICATION FOR PATENT Xo. 9499.—" Improved Hand Camera, by the U.'se of Hexagonal Drum or Box iu Interior." A. T. Dws.'i.—Dated Maij 12, 1893. PATENT COMPLETED. IMPBOX'EMENTS IK APl'ARATirs FOH RkOULATINC PhOTOOBAPHIC SHUTTERS. Xo. 12,0-211. Hesry Hill, 20, Tradescant-roail, South Lambetli-road, London, and AKTlluii Lewis Adams, SI, Aldersgate-street, London.— .lMn7 1, 1893. This invention relates to apparatus for pneumatically regulating the speed or travel of .shutters for photogniphic purposes, and con.si»ts of a pneumatic regulating device which can l)e readily adjusted or altered so as to give longer or shorter exposure as desired. The pneumatic regulating apparatus according to this invention consists of an air chamber capable of having its internal area increased or diminished as desired, by means of an adjusting device secured or affixed to that end or part fif the appanitus -which is away from, or detached from, any working part of the shutter, while another part of this air chamber is permanentfy attached to -some working part of the shutter so tli,Tt the leveroje l)etween it (the air chamljer) and the spring actuating the shutter is never varied, the regulation Ijeing obtained according to this invention by varying the size of this air chamber — and this may lie done in either of the following manners : — 1. A tube (either cylindrical or of other suitable form) closed at one end and open at the other is permanently connected at its closed enart, and consequently the at«a of said air chamber is ree done with hydroquinone formula (Ilford) in which crystals had not dissolved I" Mr. RnoFE had had markings on his plates under such circumstances. Some dis- casssion ensued, but filtering was eventually recommended. Another question was asked : " Was it necessary to rock during development ?" The rejily was ; "Yes, as particles might cause stains, and mottled apjiearance would sometimes result." Mr. Hensler asked for .amidol formula for lantern plates, and was recommended, by Mr. S. J. Beckett, to use any, but with plenty of bromide. Mr. Grant asked for probable exposure for ordinary room. Several replies were given, but/-22. Sandell plate, ten minutes, was mostly favoured. Mr. A. Barker asked: " Were uranium-toned prints permanent ? " Mr. S. Beckett said it was doubtful. He thought that, if develo]ied in the first instance with ferrous oxalate, they would deteriorate. Mr. Sodeau startled the Society with showing a shilling hand camera. He proceeded to explain it worked at /-22, amidst nuich mirth, and numerous questions were asked of an hilarious kind. Mr. T. H. Smith asked what plates were best to use for cloud negatives. Mr. Hensler had used iso. Mr. R. Beckett said they were good when there is a yellow sunset, but for a bright, blue sky the yellow screen should be used. He made an exposure last week on a Barnet rapid /-18 one-fortieth of a second, and had a good result. Clouds, he said, were often printed in too deeply ; what was wanted was delicate, not hard, clouds. Mf. Cross showed a print from a cloud negative, the negative of which he had taken by cap exposure, using slow jjlate and developer weak in alkali. Leytonstone Camera Club. — May 10, Mr.|H. E. Farmer in the chair. — The advantages of the multiple film known as the Sandell plate was de- monstrated by Mr. Herbert Fry. The lecturer opened by ]iassing round some very fine prints jiroduced by Mr. Sandell. The exposure given evidently showed that the inventor had put the plates to some very severe tests. Their advantages over other plates for hand-camera work was clearly sliown and ex- plained, some very fine snap-shot negatives being passed round, the clouds having been retained in the second film. Mr. Fry classified the advantages of the multiple film in the following order, although he considered that No. 4 was the most important : — 1st, "Hand-camera Work," in which the top film being rapid allowed for slight under-exposure, the second film absorbing the high lights and preserving the picture in over-exposure; 2ud, "Interior Work," in which the top film takes up the shadows, and the second the high lights ; 3rd, "Halation." They almost entirely do away with this bugbear, as the under films catch the rays of light, and, being a very slow emulsion, with a medium exposure, they are retained : but, even if very considerably over-exposed and they have penetrated right through the film, they still have to be reflected back through this very slow emulsion ; -1th, "Gradation." The double film gives a much longer scale of the various tones and half-tones comjiared with the resulting flatness of the single film; 5th, "Exposure." The enormous amount of latitude allowable ; in fact, the best results were to be obtained with extended exposure and weak development. The development recom- mended was that known as Cyclol, consisting of hydroquinone, 30 grains ; eikonogen, 100 grains ; rodinal, 9 drachms ; sulphate of soda, 2A ounces ; carbonate of potass, 2A ounces ; water, 20 ounces. In winter to be used one to three, and in summer one to seven. The Hon. Secketarv asked the (jues- tion as to what extent development should be carried, as he had found that when developing with pyro-ammoniathetop film veiled over, and the back had to be watched as to the progress. The Chaikman said he had had the same difficulty. Mr. Fry in reply said that the developer had been used too strong, and that by tentative development they should come up as an ordinary film, but required a strong fixing liath, eight ounces of hypo to the pint. Rotherham Photographic Society.— May 10. Mr. T. Scottox, of Derby, read a jiaper on The I'kUinutype Fmcess, and afterwards developed a number of whole-plate prints by the cold-bath method. The demonstration was most successful, and the resulting pictures were much admired for their artistic as well as their technical excellence. Dr. Baldwin (President) occupied the chaii. On Tuesday, May 2, the members had under their notice Dr. P. Jeserich's Defection of Crime paper. Photographic Society of Ireland. — May 12, Mr. M. Hedley (Vice-Pre- sident) in the chair. Subject : T. C D. Tercentenary aiul Dublin Views. — A collection of lantern slides, the joint work of Dr. E. MacDowel Cosgrave and Mr. L. R. Strangways, M.A., was exhibited on the screen. Part I. illustrated the tercentenary festivities which took place in connexion with Trinity College last July. Some very good interiors and exteriors of the University buildings were shown ; amongst others the Examination Hall, the Library, the new buildings, &c. ; portions of the procession which took place between the College and St. Patrick's Cathedral were also exhibited, in them many well-known figures can be recogniscl. Part II. comprised familiar and important buikl- ings, monuments, and views in the city, as well as some very amusing scenes in the back streets ; these latter, mostly done by Mr. Strangways, caused a good deal of merriment. Dr. Cosgrave acted as lecturer all through the evening, and kept his audience alive with interest, explaining important and historical facts connected with the University and Dublin City, many of which were quite unknown to the majority of those present. CotiTdponlrence. Correspondents sfiotdd never irriie on both sides of the paper. No notiee is taken of cominunicationa unless the names and addresses of the writers are given. FRILLING OF PLATES. To the Editor. Sir, — During the recent few weeks of hot weather which we have had there has been some trouble caused in my developing room by the frilling of plates, and, after careful observation, I have noticed tliat in nesirly every case there was one or more edge of the film entirely free from any tendency to frill. This is not an exceptional experience, but one which all those wlio are constantly using dry plates will be able to corroborate. It occurred to me that there must be some reason for the plates not frilling on all sides alike, and, after a few experiments, I found that the May 19, 1893] THE BRITISH JOURNAL. OK PHOTOGRAPHY. 319 ermanency of the ]irints?" — We have had no experience in mounting gelatino-chloride prints as opalines. We see no reason why the silicate should influence the permanency of the picture. However, a weak solution of gelatine flowed over the glass, and allowed to set. would secure perfect adhesion, and that would certainly not affect the stability of the print. Arthur Johnson- says: " Having been greatlv troubled with bubbles appear- ing on the prints in first water after fixing, I would be glad if you could tell me the cause and remedy. To prevent tliem I have tried borax in fixing bath, also methvlated spirit in lioth fixing liath and first washing water after fixing, but with no diminution of bubtiles. Streneth of sensitising bath forty grains ; also keep albumenised paper in a cnol, damp place this hot weather, ia prevent it becoming bone dry. Shall be verv grateful indeed if you can help me."— There are several 'auses that conduce to blisters in albumen prints. Sometimes it is in the paper itself, sometimes in the albumeuising, and at others in the sensitising. We should recommend the trial of a stronger silver hath. If tliat does not rrove a remedy, adoot Mr. Richmond's plan, namely, immerse tbe prints, before wishing out the silver, in a bath of methylated spirit. Th's remedy has never failed in our hands. R. Sharp. — Calico, under the name of "unbleached sheeting," suitable for backgrounds, can be had up to seven foot six, if not wider, from any of the large drapers or house furnishers. Brown paper, so far as we know, is not sold wider than about five feet. Any paperhanger would canvas a frame and cover it with paper, which could afterwards be coloured for a background of any size that might be reiiuired. If the background is for outdoor use, to be fixed against the wall of the building, it might be better to convert the wall itself into the background, by having it cemented over and afterwards painted. That is often done. Photographic Club. — May 24, Halation, Us Cause and Cure. Bank Holiday Outing, Burnham Beeches and Stoke Pogis. Photographjc Society ok Great Britain. — Technical Meeting, to be held on May 2-3, at 50, Great Russell-street, W.C. The Ddguen-cottjpe Process, a demonstration by Mr. W. England. Wb are informed that Mr. Thornton, of Messrs. Hunt & Thornton, En- largers, 347, Lorclsbip-laue, Dulwich, having retired from tlie business, it will in future be carried on by Mr. Hunt and his son, under tlie style of Hunt & Son, at that address. Apropos of some recent articles on studio construction, Mi-. Van Dyk, of 20, Ladbroke-grove-road, Notting-hill Gate Station, whose studio is built on the principle advocated by Mr. H. P. Robinson, will be happy to allow visitors to inspect it on production of visiting card. Lettonstone Camera Club. — May 20, Wanstead Park .and Flats ; leader, Mr. D. G. Iliddick. The Club will proceed from headquarters at three o'clock. 24, Demonstration, Meproducinr/ Neyalives, by Mr. Alfred J. Newton. Chair taken .at eight o'clock. 27, Zoological Gardens ; leader. Dr. W. Pickett Turner. The Club will assemble outside Portland-road Station (Metropolitan Railway) at three o'clock. Messrs. G. Houghton & Sons' 1893 Shuttle Hand camera has several im- provements on the original pattern, including a speed accelerator to the shutter, a dial which automatically records the number of plates that have been exposed, and shutters for closing and opening the lens and finder-lenses simultaneously. The camera is now issued in three series — A, for holding twelve plates or cut films ; B, for twenty-four cut films ; and C, with twelve plate sheaths and twenty-four film sheaths. The summer ramble card of the Oldham Photographic Society is embellished with an excellent sm.all group of the members of Council. The following extract from the card may give a useful hint to other societies holding outings : "Parties of not less than ten third-class passengers are granted return tickets at a single fare and a fourth, upon giving two days' notice to the railway com- pany. To take advantage of this concession, members who intend joining .any ramble should advise the Hon. Secretary three days before the date of the excursion." Central Photographic Club.— The capital of the Club Company is 1000^., and not 100/., as we stated last week. We are pleased to hear that a large proportion of the capital has been suljscribed among well-kno\vn photographers and others, and that tlie list of intending members is increasing. The Hon. Secretaries — Messrs. W. Feiiton-Jones, 12, King Edward-road, Hackney, and C. H. Oakden, 53, Melbourne-grove, East Dulwich, S.E. — will be pleased to receive applications for membership or .answer inquiries. A Photographic Society eor Wood Green. — A meeting was held at Wood Green on Saturday, May 6, to consider the advisability of forming an Associa- tion of those interested in photography and other scientific pursuits. It was unanimously agreed that a Provisional Committee be appointed, with power to add to their number, to make all the necessary arrangements for the formation »f such an Association, .and twenty-one gentlemen at once undertook the duties in question. It is proposed that the Association may be utilised by those wishing instruction in photography, and that under its auspices, during the season ther« will be a course of popular lectures delivered by gentlemen of eminence in their respective branches of science. It was agreed that ladies be admitted as members. Forty-cine names were given in to the Hon. Secretary. Ladies and gentlemen desirous of joining the Association are refjueste'd to communicate witli Mr. P. D. Coghill, 252, Wiglitman-road. Hornsey, or with the Hon. Secretary, A. S. Murrow, 32, Park-avenue, Wood Green. OONTB notice -pictorial supplements to -the BRITISH JOURNAL OF PHOTOOUAPHY" SCI5 INVERSION AND REVERSION Olf imaofs on the binocular FOCrsS'NO screen S()5 EXPERIMENTS WITH MULTIFLE- COATEli FILMS S"" oi'MS Asn Gi.rFS so; EXHIBITION OF THE PHOTOOUAPHIC SOCIETY (IF OREAT 11RIT\1N Ri'.l ARE GKI.ATIND.CHLOIUIjE I'l'.INTS PERMANENT" '■'-» INTENSIFICATION OF GELATINE PRINTS IH'II NOTI-'S nN VAHIOI'S SUBJECTS. Bv .1. R. HOPWOOII. Ph I» .';0i1 IS TH'-' PIlESENr CONSTKUCTION OF PHOTOIiRAPHIC STUIIIOS WRONG IN PRINCIPLE ? Bv W. U. HARRISON SIO NTS, Pul PHOTOGRAPHY WITHOUT »N OBJEC- TIVE. Ev ARCHD. C. PONTON SIX PRACTICAL REMARKS ON PHOTO- GRAPHING DIFFICULT INTERIORS. Bv T. N, ARMSTRONG 31» SELECTIONS. By EDWARD DUNMOBE 318 PHYSICAL DEVFLOPMENT.— I. By HERMANN SCHNAUSS 8U A NEW TELE-PHOTO LENS 815 BIRMIN0H>M PHOTOGRAPHIC SO- CIETY'S EXHIBITION 811 OUR EDITORIAL TABLE 8111 RECENT PATENTS .117 MEETINGS OF SOCIETIES 817 CORRESPONDENCE 818 EXCHANOE COLUMN 819 ANSWERS TO CORRESPONDENTS SIO THE BRITISH JOURNAL OF PHOTOGRAPHY. No. 1725. Vol. XL.— MAY 26, 1893. NOTICE— PICTORIAL SUPPLEMENTS TO "THE BRITISH JOURNAL OF PHOTOGRAPHY." Thk first of the pictorial supplements to be issued with The British Journal of Photography will be given with the number for Friday next, June 2, 1893. The subject is A Yeoman of tlie Guard (Tower of London), tlie negative being by Mr. William Brooks. The reproduction is by the process of Messrs. Thevoz & Co., of Geneva, and it is printed on a specially prepared paper, which greatly enhances its artistic effect. As a largely increased sale of the next number of the Journal is anticipated, the Publishers would be glad to receive orders for extra copies and advertisements as early as possible. DAGUERREOTYPING REDIVIVUS. Thk demonstration of the Daguerreotype process given by Mr. Wm. England on Tuesday evening, in the rooms of the Photo- gra])hic Society of Great Britain, convinced those who witnessed it that, although cai-e and skill were necessary, there was no difficulty in producing works of the greatest beauty by this discarded but ever-charming photographic process. Unlike all other systems of photography, the personal skill of the operator is the sole factor in the achievement of success. In other methods much is dependent upon the productions of the manufacturer, as in the case of the collodion or the dry plates employed ; but in this the elementary substances must be applied by the operator himself, and upon his methods of doing so depend the position he occupies in the technics of Daguerreotyping ; for we are for the moment putting out of sight the artistic element, the skill in posing and arranging a sitter, or in selecting a point of view in a landscape. In its simplest form, and as it left the hands of Daguerre, the process briefly consisted in exposing a metallic plate with a silvered surface to the vapour of iodine till it became yellow by the formation of iodine of silver, then transf^ring it to the oamera to become impressed Ijy the action of light, developing the latent image by exposing to the fumes of mercury, finally fixing by immersion in hyposulphite of soda solution, and washing and drying. This was the process as it emanated from Daguerre, but it was slow and required a long exposure in the camera ; moreover, the image was delicate, and could not with- stand the most gentle touch without being destroyed. Both of these objectionable features were speedily removed. An enhanced degree of sensitiveness was imparted by the employ- o:tb«n It is not, we would' have it at once understood, the result of imperfect fixation in the ordinary sense, that is either from too short an immersion in the hypo bath or the use of too weak a solution or one that has become exhausted. On the contrary, if anything, it is more likely to appear with a strong and fresh solution than one that has been in use some time. Nor is it the result of precipitation in the film by the imprudent use of alum or acid " elimination," although in result the appearance is very similar. It seems rather to be due to the deposition in a partially crystalline or precipitated form within the pores of the gelatine of the products of the fixing opera- tion, and in such a condition that temporarily they are not May 20, 1893] THE BRITISH JOURNAL OF PHOTOGRAPH y. 32S readily acted upon either by the fixing bath itself or by plain water. We first noticed the peculiarity some ten years ago, though without considerinj; it a fault, in a particular brand of rapid T*late8. In these, after fixation, or rather after removal from the fixing biith, the negative presented the opalescent appear- ance in the shadows to such au extent that it almost seemed to liave been treated with some semi-opaque varnish, and this effect was rather intensified tiian diminished by prolonging the fixin". Hut directly the plate was washed, especially if under « rose or tap, the veil disappeared, and the shadows became as clear as the glass itself. , Some time after that, we noticed a precisely similar behaviour •on the part of some plates of our own make, the emulsion Laving been prepared by a peculiar modification of the ammonia •i)rocess. Whetlier that circumstance had any bearing on the result we cannot decide, but it is a significant fact that it is chiefly with rapid i)lates, and since the introduction of the amiHonia process of preparation, that the peculiarity has been noticed. In our earlier experiences, as we have said, the opalescence disappeared entirely and without trouble in the ordinary com-se of washing ; but, just recently, we have met with it in an ' aggravated form, in which simple washing has 'absolutely no ©fiFect whatever. In fact, we have a negative which, after washing for half an hour or so, was found to be veiled in this manner, and was returned to the fixing bath, but without result. No alum or other matter had been used, and, though nothing out of the usual way had occiured to cause such a result, we were inclined to set it down to a precipitation of lime in the gelatine. The plate was, however, well washed for several hours and dried, by which time a decidedly yellow tint pervaded it, and this, after a very short time in the printing frame, developed into a strong brown stain. Now, at any rate, the matter began to assume a serious aspect, for we found several other negatives beginning to show similar symptoms. A fresh strong bath of hypo was made, and the result was decidedly worse. Believing that the temperature might be in fault, the bath was artificially raised to nearly 70* Fahr., when the veil was reduced, but did not wholly disappear. As before, neither prolonged immersion in the hypo nor washing efiected any improvement, and we began to suspect the hypo ; but this was from precisely the same stock that we had been using without trouble for a long time past, while it was only with the particular lot of plates that it acted in this manner ! So we were forced to lay the blame, if blame there was, to the plates, and to seek a remedy. After beating about the bush for some time, we found that tbe trouble arose mainly from the use of too strong a fixing bath ; that is to say, that in increasing the strength of the bypo, in order to fix the thicker films within reasonable time, the other trouble was set up ; in reducing the strength of the bath a perfect remedy for the opalescence was found, but then we had to face an inordinately protracted fixing. However, this difficulty was surmounted by fixing in the strong bath raised to the temperature of from 60° to 65°, and afterwards removing the plates to a much weaker solution of not more than three or four ounces of hypo to the pint of water. Another remedy was subsequently found in the acid fixing bath, that is a solution of hypo containing free sulphurous acid. The particular bath we prefer is made by adding two or three ounces of bisulphite of soda to the strong bath of eight ounces of hypo to the pint. Whatever the material may be that composes the veil, it seems to be mechanically combined with the gelatine in such a manner that the tlensi- hypo solution caimot penetrate to remove it. Water has no eft'ect, and it is only by reducing the strength of the fixing solution, and thus giving it greater penetrating power, that it is reached. The free acid, we assume, prevents the formation of the precipitate in the first place. PHOTOGRAPHY AS A BUSINESS PAST AND PRESENT. It is, we believe, generally admitted that photography, com- mercially, so far^as regards portraiture, is^at the present time in a very depressed condition. Any one conversant with pro- fessional photography during the past thirty years can recall a gradual sequence of events that have conduced to this more or less unsatisfactory state of things. It may, however, be inter- esting, if not useful, to our younger readers to refer to some of the points that have led to the depreciation of portrait photography as a business. Let us go back to the early days of collodion, say, to the time when it had generally superseded the Daguerreotype. Up to about 1855 the collodion process was more largely practised for glass positives than it was for negatives. Then the price generally charged for a small positive was from half-»- crown upwards. Several houses who worked the negative pro- cess then charged from three to four guineas for a whole-plate portrait. This was almost invariably on salted paper, and slightly finished in monochrome. About this time a firm com- menced business in the City, and made a speciality of whole- plate portraits on albumen paper for half a guinea, and copies at about three shillings each. Another firm followed soon afterwards with the whole-plate at the same price, and with the half-plate at five shillings, and the quarter at half a crown, with duplicates in each case at half price. These were then jj classed by some of the older houses as cutting prices. For If some time after the carte-de-visite became popular, prices were well maintained — they varied from about twelve shillings to two guineas per dozen, and very large businesses were done at these rates, some establishments taking fifty and upward sitters a day. One house at the West-end we have in our mind did a large business in vignetted cartes:, the price being a guinea and a half for six. Then employes all round were paid liberal salaries. Perhaps the first real step in reducing prices was the intro- duction of the club system. This, as at first worked, w^as not so very objectionable. By contracting to take tickets for a dozen portraits — each of, say, twenty persons — a reduction of twenty or thirty per cent, off the regular tariff was made. Competition in this phase of the business soon increased, and eventually the recognised club system, with its enlarged coloured portrait, came into vogue in second and third-rate houses. Par parenthese, this innovation has now culminated in the " Coupon " business, in which a dozen portraits each of four sitters are supplied for ten shillings. This was in the collodion days, and, as we have just said, employes were, as a rule, well paid, for they had to possess greater knowledge and ability than is requisite for analogous work at the present time. The plates had to be prepared at the time of using, and con- siderable skill — only gained by long experience — was necessary in the preparation of the chemicals and in keeping them in the best working condition. Consequently at that time experienced hands were seldom long disengaged. THE BRITISH JOURNAL OF PHOTOGRAPHY. [May 26, 1893 Twenty years or so ago a good-class photographic business could be commenced with a much smaller capital than now, as then more modest furniture and fittings sufficed. Quality of work counted for more than the appearance of the appoint- ments, and this led many operators to commence business on their own account, generally with prices below those of their former employers. Still, while collodion was the only process, trade, on the whole, notwithstanding competition, continued good and fairly remunerative to most engaged in it. It is often said that, in the early days, the cost of material was higher than it is now. That is true, but only to such a ■fa-ifling extent as not to make more than a penny or two differ- ence in the cost of a dozen pictures ; indeed, it is doubtful, if -the cost of mounts and finishing is considered, if it was so ■much as now. Good plain white cardboard, with a plain black imprint of the artist's name and address, sufficed for the most •expensive portraits. At the period when the highest prices ruled, retouching— an important item in the cost of portraits — ■was unknown. Hence it will be noted that when prices were at the highest the cost of production, except, perhaps, for •labour, was at the lowest. The introduction of gelatine plates has been of immense ad- vantage to photography. Of that there is no question, but whether it has benefited it from a business point of view, as -regards portraiture, is open to question. With a few months' — in some cases weeks' — practice with dry plates sufficient experience is acquired to enable some people to style them- selves operators, and offer their services as such. Consequently, ^he labour market, as advertisements show, is much overr ■stocked, hence reduced wages. Added to this, a system is largely prevailing of obtaining labour for notliing, or next to it, ^by taking " articled ptipils," apprentices, and learners for a term of years, with a premium, at a merely nominal salary. This system is not confined to operators and printers, but ex- tends even to girls for such subordinate work as mounting aud spotting. This, of course, has not only brought down wages, but keeps experienced hands out of employment. It may, however, be mentioned that it is not the cutting houses that resort to this means of obtaining cheap labour, .tliey find it more to their advantage to employ experienced hands. The present unfortimate depressed state of business amongst portraitists is mainly brought about by the continued influx into the ranks of photography both of employers and employis. It ha.s induced undue competition in every direction. Prices have been gradually reduced lower and lower, except, perhaps, in some few high-class establishments, that, unless a large business is done, they are no longer remunerative. Added to this, the demand for portraits is far more restricted now than it was soMC years ago. The contrast between portraiture as a business now and a few years back is great. How is it to be reduced % Sedudngr Sliver Cbloride to the metallic State.— In conversation with the chemist of one of the most important assay offices in the country, he informed us that, for showing this on a large scale, not for analytical purposes, he greatly preferred the use of iron to zinc. He found it mast difficult to remove the last traces of the latter substance, while with iron he experienced no difficulty. Mew Filter. — The Scientific American, a short while since, described a new filter which, though intended for water for potahle use, would be equally serviceable for photographic purposes. It con- Bista of a large porous tube made of exceedingly fine mineral flour ; the water is filtered by passing through the minute pores of the^ cylinders into a compartment below it, into whicli the cylinder is- fitted, the ■water passing from the outside to the inside of the cylinder^ The latter, when beginning to work less freely, can he cleaned by simply brushing the outer surface. The filter as constructed for sale embraces an arrangement for holding ice to cool the v,'ater during: filtration. Testingr for Bromine, Chlorine, and rodime.- There is a useful practical note on this subject in the Journal of Applied^ Chemistry, by Mr. F. P. Uunnington, ■which gives the nectssary routine in a nutshell. His process is as follows : — " From a solution acidified ■with nitric acid, precipitate the silver salts of these acids with silver nitrate solution. Having filtered off and washed this precipitate, test it in a test glass with a few drops of very dilute sulphuric acid on a bit of zinc. When the dark spongy mass of metallic silver is formed, pour off the solution of the zinc salts and examine it for iodine, bromine, and chlorine by the method of Pro- fessor Ed^ward Hart." nXr. Whipple's Successor at K.e'w.- The poi^t rendered vacant by the loss of the Superintendent, Mr. Whipple, -whose lamented death deprived science in general, and photography in i particular, of a valuable helper will be filled by Mr. Chas. Chree, \ Fellow of King's College, Cambridire. It is "one for -wliioh," as \ Nature says, " the combination of high mathematical capacity witii I a practical e.xperienee of the apparatus and methods of physical research is especially needed. Mr. Chree obtained in J 884 the hitherto unequalled honour of a First Class in the most advanced parts both of the Mathematical and of the Natural Science Triposes, and he has since been much engaged at Cambridge in experimental and mathe- matical researches." It is, therefore, evident that the latest additions to the Kew examinations of philosophical apparatus — that of photographic lenses — is not likely to be of any the less value from his accession to office. " Safety Paper " for Bank Kotes, ^c. — The Paper World does not take sufficient account of photography. We read in its columns that " the large and contiimally increasing demand for paper which cannot be duplicated by unauthorised parties for use in printing certificates of bonds, drafts, or notes, has led to the produc- tion of peculiar designs." It then goes on to describe a new patented process for making paper of this description which is said to produce designs of such infinite variety of configuration and shade that repro- duction, except from the original plate, is practically impossible. The process is ingenious enough ; it consists, iu effect, of applying the inked faces of two lithographic or other surfaces, when varieties of more or less regular smears will be produced; and they can then be printed from to form the ground pattern. It ■will occur to any reader of this Journal that such a pattern is one, above all others, that could be reproduced with absolute fidelity by means of photography, and in any colour. Solution of Gold in Cyanide of Potassium.— The last issue of the Chemical Society's Journal contains the full text of Mr. R. C. Maclaurin's paper on this subject. The conclusions he arrives at are that, first, " the presence of oxygen is necessary to bring about dissolution; and, secondly, depends upon the strength, a re- markable fact being that the maximum amount lies between the weakest and the strongest solutions tried." It has been recommended that the gold from waste albumen prints might be recovered by the aid of cyanide, the prints being allowed to soak for some time in the solution, then pressed to expel most of the Uquid, and the gold re- covered by the addition of a suitable reducing agent. There is no doubt that a large amount of gold passes into the " hypo " solution used for fi.xing prints, and may be satisfactorily recovered, for we have seen assay notes for silver so reduced by eminent refiners in ■which the value allowed per ounce for the silver has been, on account of the gold present, almost ten per cent, '•above" that g?ven for the silver from chlorides. May 26, 1898] IHE BRITISH JODKNAL OF 1»HOTOORAPHY. }tar> MM. LUMIEUE'S EXPERIMKNTS IN "COLOUJt PHOTOGRAPHY." Fbndino the publication of the precise details of the modification of M. Lippinnnn's plan, adopted by Messrs. A. & L. Luini6re in their recent experiments in colour photography, tlie results of which have caused some slight commotion in Paris and elsewhere, the following particulars of the fensitive emulsion employed, which were supplied by MM. Lumiere iu a paper recently contributed to the Soci<5t(i PVanv'aiso de Photographic, may be of interest. The novelty, or point of departure, in the preparation of the emulsion consists of mixing gelatinous solutions of silver nitrate and potassium bromide, as recom- mended by Herr Valenta, of Vienna. The emulsion was constituted as follows : — A. Distilled water 400 parts. Gelatine '20 „ B. Distilled water 25 parts. Potassium bromide 2°3 „ C. Distilled water 25 parts. Silver nitrate 3 „ One half of A is added to C, and the other half to B, the silver solution then being added to the bromide. The emulsion is then treated with a solution of a colour sensitiser, such as cyanine, methyl violet, or erythrosine, the plate being coated with the emulsion at a temperature of 40° C. When the plates are set, they are passed through a bath of alcohol, and are washed in water for a brief period, the films being very thin. This method, according to Herr Valenta, obviates coarseness of grain, and gives a film of great transparency. A too great excess of bromide is to be avoided. When the plates are dried, they are treated for two minutes with the following solution : — Distilled water 200 parts, Silver nitrate 1 part. Acetic acid 1 „ which augments the briUiancy of the image and increases the sensi- tiveness of the plate, which, however, loses keeping properties. The plate is again dried, and exposed according to the method given by Professor Lippmann. The developer employed by MM. Lumiere is as follows : — 1. Water 200 parts. Acid pyrogalUc 1 part. 2. Water 100 parts. Potassium bromide 10 „ :i. Ammonia D = 0900 at 18° C. The developer being thus mixed : — 1 lOJparts. 2 16 „ !5 5 „ Water 70 „ The importance of a standard solution of ammonia is clear, as the least variation in strength affects the results. After development the plate is washed and fixed in a solution of cyanide of potassium, 5 to 100. MM. Lumiere say that a developer consisting of an ammoniacal solution of copper chloride has given them good results, but they have had to abandon it on account of its instability. MM. Lumiere added that in photographing coloured objects the ultra-violet rays were cut off, and the violet and blue diminished by placing in the path of the luminous rays, in the camera, a vessel with parallel faces, containing a solution of yellow colouring matter, such as Victoria yellow, uranine, or primuline. This was how they obtained the results that have been recently referred to. AMERICAN NOTES AND NEWS. FecuUarltles of American Joumalljun.— The American journalJHts have a neat way of imputing to their rivals any departure from such a branch of ethics as takes cognisance of the coincidence of phrase with fact. One of our New York contemporaries, the I'hiito- (jraphic Times, is in his current issue admonishing his brother who edits Wilton' » Magazine for his mal-ethics in recording something of minor and local interest. He does not stoop to that direc^ess of expression not unknown to or unpractised by some accredited journalists in the south and west of the American continent, and which provokes the rejoinder, " You're another," but mildly states that the ilagellated rival is losing his sight and must be provided with spectacles. And why ? Because they are not agreed as to the titles on a row of books in the background of a portrait, said titles being altogether illegible. It is the scene in the war between the Big-endians and the Little-endians (vi(k Gulliver's Travels) enacted over again. The Philadelphia ZSxhlbltlon.— There can be no doubt that the recent Photographic Exhibition in Philadelphia must have been a good one. The names of the competitors in the catalogue, and the critique in the American Journal of Photography — a model of terseness— assures us of that. It appears, however, that the exhibits from this country stood out in commercial contrast with those from America, inasmuch as a preponderance of the former were labelled " For Sale," whereas the latter were not ; and it is said that the pictures of the two nationalities could be distinguished each from the other by this label alone without necessitating an appeal to the cata- logue. But has it not long since been said of us that we are a nation of shopkeepers? It behoves us to speak quietly of the Customs Taxes levied in America on goods entered for exhibition, but which are at the same time " for sale." Of the twenty-six medals (silver i awarded, one went to Germany, while thirteen came to the United Kingdom, the other twelve being captured by Americans. Tie Photographic Society of Philadelphia are certainly entitled to the honour of having issued the finest and most ornate catalogue, yet known in the history of the art science. It is adorned with six full-page illustrations Ijy member.^ of the Society. The Photog^raphers of Axnerlca.— A firm of engravers and publishers in Chicago are about to prepare a work on the photo- graphers of America. They anticipate that at least ^"000 photo- graphic artists will visit their city during the Convention of the Pliotographers' Association. It is to contain the portrait, name, address, and biography of every photographer who subscribes five dollars (1/., payable in advance), who in return will receive a copv of the book, which is to be got up iu the highest style of the art, printed on heavy enamelled paper, bound in gold and black, 12 x it inches in size, containing at least 400 pages and twenty fuU-page illustrations from prize photographs. Each photographer furnishes his own portrait and biography, the engraving being done at the expense of the Company. Three hundred and sixty dollars (over 70/.) are to be given in prizes for the best pictures entered for competition. The Kodak Victory. — It is known that for some time past an important lawsuit has been going on in the United States of America. The Kev. Hannibal Goodwin, of Newark, N.J., claimed priority in certain processes in the manufacture of sensitive films as employed by the Eastman Companj', and he went for the latter in the law courts, in one of which he gained the day. Bat the decision has been reversed by the Commissioner of Patents, who, it seems, has decided not to grant Mr. Goodwin his patent, ftobably by this decision something like a million dollars will remain undisturbed in the coffers of the American Eastman Company. METOL. WiTnotJT committing oneself to the absolute statement that the last new developer is better than anything before it, it is, perhaps, poeuble 326 THB BRITISH JOURNAL OF PHOTOGRAPHY. [May 26, 1893 to claim that it possesses good features that none of its predecessors do. I have tried most of, if not aU, the modern introductions that have been intended to supplant pyro, but have not yet found the one that will, to my idea, do so. In metol I think we have the nearest approach to a developer possessing the same range and power as pyro, while it is undoubtedly free from the objectionable features of the latter, notably its dreadful staining proclivities. It has, however, I think, one feature which will be considered by many a decided advantage over pyro, a feature which, although I am not a believer in " one-solution " developers, I cannot help recog- nising as having its value. I refer to the power it gives of modifying the character of the image by simply varying its strength without altering the proportions of its constituents. This is a quality possessed to some extent by pyro, and, indeed, more or less by all the newer candidates for favour ; but in none, so far as my experience goes, is the range of power so great as in the case of metol. By varying the proportions of the stock solutions (where separate solutions are em- ployed) as recommended in the formulae issued] with the metol, a great alteration can be made in the character of the image ; but this is, of course, impossible where a one-solution developer^^is employed. In this case, however, if the stock solution be made of such a strength that, used alone or with a given proportion of :water, it represents the highest degree of energy desirable, and with a given exposure renders the greatest softness, simple' dilution with a further pro- portion of water will effect all thatjis necessary in the] way of giving greater contrast. As regards the necessity for the use of bromide, although I am always partial to a small addition even in commencing development, I think metol shows less absolute want of such addition than any other. For short or normal exposures, indeed, if tlie dish be well shaded during development, I can see little difference if the bromide be omitted from the solution until all the details are well out ; at that stage, or where intensification] begins, bromide is a necessity with every developer, but more especially with pyro. On one occa- sion, after mixing up a fresh stock solution of soda with hot water, I inadvertently applied the mixed developer in a quite lukewarm state, but the only effect was that the image appeared almost instantly and developed as rapidly as one on collodion. A strong addition of bromide, however, instantly checked it, and brought it within easy management. Those who are not greatly enamoured of one-solution developers are more likely to take to the system with metol^than with any other, for, strange aa it may appear, repeated use to the extent of three or four times, at any rate, does not seem to greatly alter its action. But A better plan than relying on the single solution, where economy is to "be practised, is to employ two separate developers, or one developer and one intensifier. Thus, say, half a dozen plates are to be de- veloped, I would set aside one portion of developer sufficient, to cover the plate, with which to bring out the details of the picture, using it at its full energy. To another portion, in more dilute form, I should add a few drops of a ten per cent, solution of bromide, and use that as the intensifier, as it will continue to operate upon the image after the details are out without any further development. This plan can be followed either with single or separate stock solutions, and, if only half the work of finishing the negative be thrown upon each of the two working solutions, they will hold out very well for half a dozen developments, provided always the exposures have been sufficient. In my own way of working, I prefer to use a fresh quantity of solution for each plate, and this I apply at full strength — i.e., the fullest working strength — until details are out, and then dilute it according to the appearance of the image, adding promide as the action proceeds. The latter must be carefully used, as it is very powerful in stopping the action of the solution on the finer details, and if added in excess will produce hardness. The published formulae for use with metol are rather puzzling in their nature, but may bo greatly simplified. I take it that for normal development from two to three grains of metol, and about twenty grains of carbonate of soda to each ounce, form suitable proportions. If a stock solution of metol containing six grains of that substance and a drachm of sulphite, and one of soda crystals containing two ounces to the pint, be used, they may be conveniently mixed to form amy desirable combination. Let the stock solution be : A. Metol 120 grains. Sulphite of soda 1200 grains. Water 1 pint. B. Soda crystals 2 ounces. Water 1 pint. For normal development use equal parts, and add a little water if the subject is one that wants contrast. For under-exposure use more of A than B, and vice versa, bromide also being added in ten per cent, solution in the latter case. A single-solution developer, where such is preferred, is made as follows : — Metol 120 grains. Sulphite'of soda 3 ounces. Soda (crystals) 2 „ Bromide Jof potassium 10 grains. Water 20 ounces. One part of the above diluted with an equal volume of water forms the normal solution, more' dt less-.water being used in proportion to the length of exposure. W, B. Bolton. JOTTINGS. To call an exhibition of photographs a " Photographic Salon " is a piece of affectation bordering on snobbishness. To add another to the already plethoric Jnumber of photographic exhibitions that are held in the autumn in and about London invites and deserves failure. To run an opposition show to the Photographic Society's Exhibition practically at the same date and only about 500 yards away is the mean revenge of a vindictive clique still smarting under their whipping of two years ago, and made furious by the circumstance that the Society they deserted is getting on better without them than with them. To say that the photographs to be hung will be of " pictorial merit " only, and will be selected by a Committee, chosen, of course, by those we can all easily guess at (with power to add to ,their number), and that therefore "the public" will have an opportunity of seeing " the best productions of photography from a pictorial point of view," implies that no such opportunity has before been given to " the public,"_which is untrue. Habitual readers of these "JJottings " will remember that I fore- shadowed the " Photographic Salon " last August — nay, even gave the^name of the street in which it is to have its home, Piccadilly. On one^point connected with it I was, however, wrong — namely, as to the medals. There are to be no awards, it seems. But, to make up for their absence, I know what will happen. The organizers of the Salon will pay special attention to the representatives of the lay press, and trade upon their ignorance to secure effusive and puffy notices, so that the public may be deluded into the beUef that the Salon really has a monopoly of the " best productions of photography," and this of course will send up the commercial value of the pictures, arrangements for the sale of which will be made " at a commission of fifteen per cent." I wonder who will do the Times notice ? Mr. Msskell ? That the Photographic Salon is a deliberate and carefully planned attack on the Photographic Society's Exhibition nobody can deny. This is a free country, thank goodness ! and I am sure the Society and its friends are not the people to be dismayed by a little opposition, so long as it is of a fair and legitimate nature. But that of the Photographic Salon is not. The support which the malcontents and their satellites are giving to it is a thing which causes no surprise, but there are many other persons on the Committee whose presence there I cannot understand, except on the ground that the Society, according to their ideas, has neglected " pictorial merit," and has not shown " the public the best productions of h ography from a May 20, 1893] THE BRITISH JOTJBNAL OF PHOTOGRAPHY. 327 pictorial point of Tiew," a proposition whicli, of course, is absurd. Hence the Socioty hivs a grievance at seeing so many of its best men in league with its enemies, and I therefore b'jg to invite the various members of the Photographic Society of Great Britain who are on the Salon Committee, to explain to the photographic public how it is that, having themselves been successful exhibitors, or judges, of the Photographic Society for years past, they are now sup porting a rival show whose only claim to attention is the coolly impu- dent way in which it is trying to arrogate to itself the right or duty of taking "pictorial merit" in photography under its wing? The attitudes of these gentlemen are so equivocal that explanation is almost imperative in the interests of their own reputations. " Audacious Operator," in the Journal for April 28, does me the honour to ask me for a " critique to the point " on the question of the determination of the speed of plates, and at the same time he points out with some force that the sensitiveness of a plate probably varies witli its age, but that the speed number originally given to it remains. The vastness of the subject deters me from attempting to tackle it in the course of a single paragraph, and I can therefore only deliver myself of a brief reference to it. By far the larger quantity of dry plates made are manipulated by professional photographers and habitual plate-users, among whom 1 fancy the only kind of plate speed required is uniformity of rapidity. Let a dry-plate maker send out plates which do not appreciably vary in speed and quality, and the photographer will be quite content to work them without the assistance of speed and eensltomcter numbers. It seems to me that the adoption of different speed numbers for each batch of emulsion made puts a premium on irregularity of rapidity without assuring that the relative rapidities with which the plate boxes are marked will be confirmed by the camera test. Thus it is conceivable that a given brand of plates may, within the space of a few days, possess half a dozen degrees of sensitiveness, and be put on the market by the maker without a pang, whereas in pre-Hurter & Driffield days he might have hesitated to use an emulsion which sliowed an appreciable decrease or increase of sensitiveness for a plate of standard rapidity. Both sellers and buyers would, I fear, be likely to be confused by the multiplication of speed numbers which would follow upon the univei-sal adoption of the Hurter & Driffield system, which, however, is not likely to happen yet. I must thank Mr. H. W. Peal for his courteous reply to a former jotting of mine, asking for evidence upon which he based a state- ment that amidol allowed one to reduce the exposure to about one-third that required for pyro. It seems that Mr. Peal was not comparing the two developers for general work, but for very slow plates used for copying, the pyro developer against which amidol was pitted being, he says, very well restrained, the amidol having only a very small quantity of bromide. This, of course, is no comparison, and liad Mr. Peal been reported in the sense in which he writes I should not have commented in the matter. Amidol will no mure allow a photographer to successfully give a third of the exposure required with pyro than hydroquinone, as claimed upon its first introduction a dozen years ago, will allow him to give one-half. I have proved both statements wrong by simple experi- ments; and as regards amidol — which possesses many good points, especially in rapidity of working, suitability for bromide paper, and possibly some advantage in bad cases of under-exposure — the opinion I expressed a month ago as to its not allowing one to reduce ex- posures for pyro two-thirds is curiously confirmed by one or two speakers in your report of the meeting of the London and Provincial Photographic Association for May 4, which is given on page 301, May 12. " In pointing out that a plate which has been simply exposed in the camera and, without development, fixed, leaves a deposit which may be intensified as it were by acid development, Mr. Hermann Schnauss, in his paper on Physical Development, suggests the equally interesting fact of the known difficulty of entirely destroying the developed image in a plate. I have applied all kinds of reducing solutions to gelatine negatives without obtaining perfectly clear gelatine free of some kind of deposit which did not admit of slight accretion under Intensification. An iniage of some sort remains behind, the precise nature of which Is open to doubt, although it ia possibly a compound of gelatine and silver. This opens up a field for speculation as to whether development is responsible for the whole of the deposited image, or whether the exposure does not at once reduce a portion of the haloid to metallic silver in some unfamiliar form, which at once enters into combination with the gelatine, the develop- ment of the sub-salt acting as an intensifier of the original image, to which the term latent is therefore a misapplication. At any rate, the undoubted presence and persistence of the undeveloped and developed impression in a plate seems to me to be a point worthy of notice in any theory which seeks to explain the nature of the photo- graphic image. The idea of the Manchester Photographic Society in providing a large camera, with the "usual trimmings," for the use of members, on the co-operative principle, is one that other Societies might adopt. Most photographers at some time or another feel the want of a large camera, and, if it could be obtained from their Photographic Society, the .small fees charged would help to pay for its cost. Optical pro- jection and enlarging apparatus are also things which every amateur cannot afford to possess himself, and for the loan of which he, no doubt, would be willing to pay a fee to his Society. When such things are wanted, they are wanted badly. Certainly Photographic Societies could do worse than add to their attractiveness and useful- ness in such a direction. As regards a large camera, I should think it only the correct thing for a Society to possess a camera of its own for official use, a.«, in case an exposure by artificial light is desired to be made, it is a handy thing to have. Might it not also bo an induce- ment to beginners to join a Society in which a camera was kept with which they could take their first plunge into the small sea of troubles which photography,has in store for all its votaries ? A further addi- tion to the usefulness of I'hotographic Societies would be the general adoption of a'svstematic jilan of laboratory and field instruction for novices,such as I am glad to see put in|practice by the North Middlesex and other Societies. I rub my eyes at reading a complaint of frilling in your last number. 1 do not think that Mr. Lambert's suggestion that the evil of which he has had such recent experience, after all of us had gro^vn to regard it as a thing of the past, can be, except in extreme cases, due to the cutting of the plates. Otherwise every quarter, five by four, half, seven and a half by five, and the many intermediate " odd " sizes issued from the manufacturers would be open to suspicion on that account — an idea which does not hold water. Cosmos SELECTIONS." The Sky Pokhon of a Landscape. Wf. wUl now consider the treatment of the sky portion of a landscape. Many photographers capable of doing most excellent work content them- selves with turning out prints with white, or only slightly tinted, skies, instead of supplying proper cloud effects. The trouble of adding these is so very trifling, in comparison with the improvement they effect, that I am surprised not to see them more universally adopted than they are. Cloud negatives themselves are very easily made, although there seems to be a genuine and wide-spread idea that cloud photography requires some special skill, different from the usual kind. Given clouds, it is quite as easy to photograph them as anything else, perhaps more SO. The only imperative condition is absence of haze. A white dress, covered with white lace, is infinitely more difficult to deal with ; only, start fair, knowing the ;kind of negative wanted, which will be a thin one, with good contrasts. Stop the lens down to /-64, use a moderately alow- backed plate, and give about half a second exposure. Use a well- restrained developer, and the thing is done. A very rapid plate, with a drop shutter exposure, will not produce such nuitable negatives for printing-in skies as the slower process. Plates containing iodide are to be preferred. One preoantion is never * Concluded froa pogs 31^ THE BRITISH JOURNAL OF PHOTOGRAPHY. [May 26, 189S to Iiave the sun itself visible on the negative unless covered by clouds of more or less density, or something equivalent to them. If a sun or moon is wanted in the picture, put a small, round, opaque spot on the negative to do duty for it, using artists' licence as to the size, which will be two or three times as large in proportion as it would be if photographed. More- over, with the sun full on the lens, there is generally fog or a patch of blurring in addition, quite spoiling the negative. Clouds, although less effective as "cloud effects," are more useful for printing in if taken look- ing away from the sun, and at the same time more appropriate, the majority of landscapes being more often than not lighted at varying angles from one side or the other, and not from the front. In a great many negatives the sky is so cut up by foliage that mere indications of clouds are sufficient, and if the lighting of them is different to the land- scape, unless it ia very pronounced indeed, the error would rarely he noticed, if at all. I am afraid I lay myself open to a wigging"_for making such an assertion ; at the same time, I believe it to be a tact. If we are to be so critical in respect of clouds in a. photograph, why not be equally so of those in a painting ? Artists of the brush and palette^I am afraid err as much as those of the camera in this respect. In close connexion pictorially with the sky in the photograph is water, especially large sheets of it. If it happens to be still with a good reflect- ing surface, only sky reflected in it, the clouds should be printed on it lightly in reverse — that is, by turning the negative over and printing from the wrong side— but in proper position with regard to those clouds of which they are supposed to be reflections. If only a small patch of water comes white in the print, that can be rubbed down with spirit or a tint printed on, for a white spot of that kind is always an eyesore. Rubbing down or tinting will harmonise it with the rest of the picture. Exposure and Density. " Exposure and density " has been a somewhat contentious subject, so 1 will say little about it more than that a full exposure for all general work gives us better results than we can possibly get witli the least under- timing. A negative, perfect from a chemical point of view, does not always produce a print perfect, in an artistic sense, with respect to atmo- sphere. I have an idea that the best prints are always from slightly over-exposed negatives, from the pretty negative point of view. It is a popular fallacy that hy fully, not over, exposing a landscape the distance is buried. In an under-exposed negative, this ix generally the ease if the detail in the darker parts is properly brought out. The time of develop- ment necessary to get out detail in these shadowy parts does assuredly over-do the distance ; but in a well-judged exposure the detail in the foreground (unless in exceptional cases) comes up nicely with the dis- tance, and the harmony throughout is retained. In some cases brush development is exceedingly useful, and indifferent exposures may be made to pass by its judicious use. Few rules have no exceptions, and in this matter, if a slight haze exists at the time of taking the negative, a shorter exposure is warranted. The least over-exposure under such con- ditions would be undoubtedly a mistake, tending to over-density in the distance. Development. A word or two about development. A good estimate of the quality of a developer is that it shall with the least density, or rather opacity, print the strongest image. The developer that comes nearest to this standard is the one to choose, for I prefer that the printing qualities shall chiefly depend on the colour of the image rather than on its opacity. Some negatives of a very non-actinic colour are quite ghostly in appearance, and yet produce the most charming prints. There is, in fact, a softness, richness, and brilliancy in such prints that is quite unapproachable by any other class of negatives ; moreover, such cliches lend themselves to almost all processes bettor than other kinds. In development I prefer flooding the plate in the first instance with the developer minus the alkali, adding this afterwards a little at a time, according to the effect produced, my favourite mixtures being pyro-soda for indoor work, and pyro-ammonia for out- door. For very dark interiors rodinal is, I think, as good as anything I have tried; it had rather the advantage in a competitive trial with ammonia on an Ul-lighted room, half an hour being given to each exposure. It produced more detail in the shadows than the ammonia did. The chief objection to the amidol and eikonogen class of developers is, they have to be made apparently denser than they ought to be with pyro developers for a standard, and lose some printing delicacy in con- sequence, as well as being somewhat deceptive as to tbek printing force. Reduction in the Hypo Hath.— Some interest has lately been exhibited m the effect on bromide prints of prolonged immersion in the hypo- sulphate bath. Reduction will take place in a negative, irrespective of the developers, if the plate is left soaking for some" hours in it. I have { several times found soda and ammonia and pyro images almost entirely ' obliterated by leaving them all night in the bath. At the same time, I have let similarly developed negatives remain quite as long in it with scarcely any alteration of density. Why some should fade and others remain unchanged I am unable to say authoritatively, but in all proba- bility the bath was stronger at one time than the other, for with the hypo bath, so that it was snfliciently strong to fix in a moderate time, I have never considered the strength of much importance. HiLATION. The subject of halation or blurring has also been to the fore of late and is a matter to which I have been obliged to give considerable attention, especially since the advent of rapid dry plates. I think you will agree with me that this fault has increased in ratio with the sensi- tiveness of the films. With highly sensitive films, no precaution that I know of will altogether prevent or even mitigate it if the subject is highly reflective or possessing strong and abrupt contrasts. Having at one time or another had considerable experience with interior work, to which I am very partial, I do not think I can over-rate the importance of securing plates and conditions as little liable to this fault as possible. There is no doubt that careful development will mitigate the trouble, but given a very rapid bromide plate, and a subject of a trying nature, neither development, backing, nor anything else, so far as I know, will prevent it. On this account I prefer a rather slow plate, containing a fair amount of iodide, as best for such subjects, and calculated to give as great a freedom from blurring as we can hope to get. It seems to me that a thick film unless heavily charged with silver salts, is worse than a thin one, because there is more probability of, and opportunity for, lateral dispersion of the light in the film itself. Rapid films, from their colour and coarseness, favour blurring. The wider separation of the opaque particles in a trans- parent, or semi-transparent, medium, like thick gelatine, permits of an easier infiltration of the light through its substance than the finer and more dense conditions of the bromide, and therefore slower films. If blurring depended entirely on reflection from the back of the glass, then a good backing would be a certain cure in all cases, which we know from experience it is not. Many plates of considerable density and yellow- ness without any backing are almost free from this fault, for the reason just stated. An additional drawback to very rapid plates is their tendency to reversal, a more annoying fault, if possible, than blurring ; it does not appear so unsightly on the negative, for the image remains clear and distinct, and, unless in some conspicuous place, may be overlooked, but in the print there is no fear of this oversight. I have had some other- wise excellent negatives rained by it, for they set doctoring at defiance, unless of the most elaborate description. When plates are very prone to this effect, they are useless for good interior work, and so for many reasons I prefer to work with a plate of only moderate rapidity, and think bettct general work is obtained on them by far than on those of the very rapid. Edwakd Dukmobe. COMPOSITE HELIOCHROMY. [A Second Paper on Photogmphy in the Colours of Nature, read at the Society of Arts.) Tiie heliochromosoope was first publicly exhibited one year ago in London, before the Royal Society, the Iloyal Institution, and the Society of ;Arts, in connexion with demonstrations of the process of composite heliochromy upon which I have been working for several years. As was explained in my paper of May 25, published in the Journal of the Society of Arts of May 27, 1892, the heliochromosoope and its triple photograph, or chromogram, are calculated to reproduce the colours of nature as readily as the stereoscope and stereogram reproduce binocular perspective. The photographic process by which the colours of nature are repro- duced, was perfected in theory nearly five years ago, and its capabilities were demonstrated at a meeting of the Franklin Institute, in Phila- delphia, in November 1888. In order, however, to operate the process advantageously, it was necessary, not only to provide a special optical lantern for superposing on the screen the three images of the chromogram , but also a special camera which would enable the triple negative to be made by the exposure and development of a single sensitive plate, as in ordinary photography. I designed such a camera in 1891, and by means of the heliochromoscope, a modification of the camera, by which the three images are blended without either lantern or screen, I reduced the method almost to the simplicity of stereoscopic photography. Owing, however, to certain inherent defects in the photographic nega- tive-making process, which have long been known to affect the rendering of gradations in monochrome photography, and, therefore, must also affect the colour-rendering, I have since given mu.oh study to realisi iUj 26, 1393] THE BRITISH JOUENAL. OiT PHOTOGRAPHY. the mo«t favoarable conditions (or reducing such defects to a minimum, and to dotlning the nature and extent of tbo limitations which thejr impose. Much exi)eriment has also been devoted to overcoming other diSlcnUics which I shall mention, and, although a truly astonishing illusion of nature is realised in the heliochromoscope, I estimate that it ma.v take another year to carry out all the experiments, and make all tie nioasureinents necessary to enable me to finally demonstrate the lae-violet, the three images of the triple photograph are not made through red, green, and blue-violet glasses, nor by the action of red, green, and blue-violet rays, but each by the joint action of all rays that have power to excite the respective fundamental colour sen- sation. Not only do the red rays, but the orange, yellow, and yellow-green rays also excite the funda- mental red sensation ; the orange rays aSect it even more powerfully than the pure red. The photograph, to represent the effect upon the red sensation, is, therefore, made by the action of all these rays, and in due proportion, in accordance with Maxwell's .measurement. The photographs of the green and iilae-violet sensations are also made by the joint action of rays of various colours, in proportion to their power to excite the respective fundamental sensations, accord- ing to the measurements of Maxwell and Abney. But, when the images of the triple photograph are blended into one, by means of the triple lantern or the heliochromoscope, the photograph of the red sensa- tion is illuminated by red light only, the photograph of the green sensation by green light only, and the photo. ^aph of the blue-violet sensation by blue-violet only, lln other words, the tliree images of the chromogram jrepiesent the action of all incident light upon the .respective fundamental colour sensations, and the light iby which each image is illuminated in the lantern or heliochromoscope represents the sensation itself. The result of blending into one the three images of the chromogram— each being illuminated by the kind of light intended for it — is a faithful reproduction of the object photographed, in all its subtleties of light, .and shade, and colouring. Last year my projections on the screen were made with the lime-lightr, ;tlie performance of which was very unsatisfactory to me in comparison with sunlight projection which I had employed at my house in Philadel- iphia. Now I am provided with a lantern adapted for electric light, and will repeat my demonstration with it before proceeding to describe the .colonr-camera and heliochromoscope. In this lantern a single arc electric light is the source of illumination. After being collected by a condenser system in the usual manner, the light from the arc is sub-divided into three portions by means of a system of mirrors, some of which are trans- iparent, so as to both reflect and transmit light, snbstaritially as in the heliochromoscope camera, which I shall describe later on. In the palh of .«ach divided beam of Uglit is placed a smaller condenser and a colour- >^acreen ; in front of these a chromogram ; and then the objectives by which the images are projected and superposed. This device differs from .all others that have been proposed for the purpose, in tliat the disc of ittght on the screen remains white when the electric arc varies its crater. The systems formally proposed for use with a single light would be quite useless under such conditions. I commence by demonstrating the produ. Light transmitted by the image of the blue- violet sensation, V, passes through the blue-violet colour screen, V, to the silver mirror, 3, sideways to the transparent mirror, 4, forwards through the transparent mirror, 2, and objective, D, to the inclined mirror, E, and upwards into the eyepiece under which a blue-violet image is formed, exactly coincident with the red image. That portion of the light which passes through the trans- parent mirror, 4, is lost, and also that which is reflected downwards by the transparent mirror, 2. F. E. Iv£g. {To be continued.) MABION'S NEW SUMMEB AND SEASONABLE NOVELTIES. On of a visit to Marion & Co.'s, Soho-sqnare warehouses, a hand camera the invention of Dr. Krngener and the occasion we were shown possessed of excellent features. Numerous are the inventions that have been introduced to solve the problem of the transference of sensitive films to the camera and their exposure with the maximum of certainty and the minimum of risk and trouble. This is claimed by the firm to have been attained in their Simplex Film Camera, an external view of which we here give, and in which pro- vision is made for bringing fifty films into the field, transferring them to the focussing plane of the camera, and, after exposure, storing them in a reservoir, where they remain secure from the action of light. In what way all this is accomplished we shall endeavour to explain. The films are cut to the size required and are flexible. A long band of opaque paper is provided, and is folded to the size of the plate. At certain intervals there are narrow slips of paper pasted on the band, underneath which one end of a film is slipped. The band is then folded zigzag fashion, a, b, c, when the second of the series of paper slips comes to the proper place for receiving another film, which is retained in situ by a repetition of the folding of the band ; and this is repeated until the whole of the fifty films have been put up in a packet, which is then inserted in a recess at the back of the camera. Meantime, the front fold of plane is a plate of optioUy worked glass, and by means of a spring behind the package is pressed against it. On drawing out the projecting end of the band D, the first of the series of films is brought up, hard pressed against the glass focussing plane, B. After exposure, D is pulled, when the exposed film, C, rises, and, caught against the sloping cover, falls forward and flat down into the reserve, C, above. A continuation of the pulling at D results in the next film in the series replacing the previous one, and in due course it, too, is deposited on the anteoedaneous pile, C. This goes on until the last of the fifty films have been exposed and lodged in the- chamber above, when the services of a dark room or a changing bag must be had recourse to in order to affect the depletion of the chamber C and the refilling of chamber B. The other parts of the camera, its lens, shutter (time and instantaneous), focussing details, and other matters, including its two finders, its level, the means for applying tension to the shutter spring, can be easily conceived of. The stand is a species of alpenstock, the limbs of which are jointed a few inches from the top, and which when expanded yields a flat solid table on which to place the camera, with a mechanical contrivance for enabling it to be pointed up^ wards or downwards when the ground is uneven. This stand, we may observe, is adapted for other cameras than this. The Eadial, a camera of Marion will, and after exposure may be returned to the place from whence it came. An addendum to this system consists in having an additional set of sheaths, which may contain quarter-plates or any size intermediate up to those for which the camera has originally been adapted. This- gives an additional power to the holder of this new size, in which the- greater is thus made to include the less. We were shown a large quantity of the fixing and developing cartridge* of which we spoke in a recent issue, and which we are told are bein^ much demanded. We were also shown an exceedingly low-priced hand camera, " Th& Alphoto," the prices of which commence at 8s. 6rf. each, with achromatic lens. In this the focussing is ad libitum from two yards to infinity. The Collapsible Plate Back is one of those handy pieces of apparatus that occupies but little space when folded up, but when expanded it affords space for a dozen plates being racked up for drying. The foregoing cut shows the rack so well as to render further ffescription unneoes- pack away amongst one's travelling to the band has been passed over a roller, and brought out through a slot behind ready to be grasped by finger and thumb. The exposing or focal sary. It will prove convenient impedimenta. A very pretty and simple way of storing and displaying negatives or transparencies was brought under our notice. It consists of a series of sheaths hinged together, capable of being folded up in small space, or of being in a moment opened out, so as to show the negative or trans- parency at a glance. This form of putting up negatives certainly must approve itself to those who in the rush of business desire to pick out a negative or transparency at a moment's notice. It is only necessary to undo the fastening, when at once the whole contents are displayed for examination. In the rooms devoted to frames and mounts, we might well feel excused from breaking down altogether in our powers of note-taking. An exceedingly beautiful example of the adaptation of English-dressed antelope skins, made up as frames with corner piece and entourages in silver, are without doubt the most elegant forms we have seen in which photographs can be set. . . /These range in sizes from cartc-de-vislte midget up to panel. We also saw close imitations of the above in other skins, mounted both in silver and in imitation, at a much lower price of course. We have already, some time since, spoken of a series of artistic prints specially made by Downey which were sold at a marvellously low price (eight shillings a dozen). A third series of these, of larger size, 19 x Ift net size of print, is now in course of preparation, and is expected to be ready in a month. From the specimens we saw, we would suggest their great utility in the show-room. In this depai'tment were also to be seen antique miniatures, which consisted of carbon opals, painted and unpainted, in those old-fashioned flat ebony frames of a former period. These ought to be useful to portrait photographers; ivorine frames and easels suitable for every class of pictures, and made in sizes from cabinets upwards ; also an- May 20, 18tf3] THE BlUTISH JOUKNAL OP PHOTOQilAPHY. 881 Kxoelaior Album with specially thick mounts, but which, alas ! will not be on the market (or two months yet. We must not, however, omit to mention a scries o( direct sepia platinum prints, by Edwards, of English historical buildings, nor of a large variety of designs for IJirthday, Christmas, and New-year's mounts, folding and plain, in which artistio and mechanical genius has been laid extensively under contribution. If these, and quite a large number of chaste and elegant forms of mounts for every size of portrait, and in every variety of tints, including some ^uite new, do not give a fillip to bnsiifess, we know not what will. RECENT PATENTS. PATENTS COMPLETED. lH)-ROVKM£NTS IN PhOTOOHAPHIC LKNSES OR OlURCTIVES. No. 4692. Paul Rudolph, Carl-Zeiss-strasse, Jeua, Saxe-Weimar, Germany. April 22, 1893. This invention relates to photographic objectives, and its purpose is to remove the indistinctness of tlie marginal portions of the image by reducing, as much a.s passible, the "astigmatic aberration. As indicated by their name, these aberrations are caused by " astigmatism," that is to say, the property possessed by the rays of an oblique pencil of light transmitted through an objective of not uniting in one and the same point the rays lying in the primary or meridional section of siich pencil uniting in one point, and the rays lying in its secondary or sagittal section uniting in another ])oint ; or, in other words, tlie focal length of the rays in the primary section differs from the focal length of the rays in the secondary section. Thus are formed two partial focal points. The distance of these two partial focal points, or the difference of the two focal lengths, is called the "astigmatic difference." The latter is termed ix)sitive when the focal length of the ray in the primary section is greater than that of the rays in the secondary section, and it is called negative when the focal length of the rays in the secondary section is greater than that of the rays in the primary section. As it is possible to so compose or construct lenses as to cause them to manifest a predetermined .istigniatic difference, either positive or negative, this astigmatism supplies in itself a means for obviating its prejudicial effects. With this object the objective can be constructed with two distinct or separate lenses, or systems of lenses, for example, one of which is so composed as to produce a positive astigmatic difference, whilst the other is so arranged as to give rise to a negative astigmatic difference, the said two differences being cansed to neutralise each other, Surh a double objective, or " doublet," as it is called, is descrilwd in the Specification annexed to British Letters Patent, No. 6028, dated April 21, 1890. In this double objective the correction of tlie said astigmatic aberrations is obtained by combining an achromatic lens, the positive member of which, being the collecting lens, is made of glass having a higher refractive index than the glass of its negative member (that is to say, the dispersing lens to which it is cemented), with a second achro- matic lens, the refractive indices of the two cemented members of which are contrarily graduated. The neutralising effect obtaineil by this reversed or inverted comimsition of the members of a doublet relatively to the astigmatic aberration is principally dependent on the fact that, in virtue of the said com- bination, the inner surface, or "surface of union," in the one member (that is to say, the surface on which the component lenses of the member are united together), is caused to act as a collecting lens, whilst in the other member the surface of union is made to act as a dispersing lens, and so with reganl to the influence upon the focal length, as well "as upon the spherical aberration of the respective member. Now, the present invention consists in a new organization or combination of juJiromatic lenses, whereby the same neutralisation or correction is brought about within a single system of lenses cemented together. For this purpose the system is composed of three individuJ lenses, iu such a manner that the Inner member is a collecting lens, and has cemented to it on each side a dis- persing lens, one of the latter having a greater and the other a smaller refrac- tive index than the collecting or intermediate lens, or that the said inner member is a dispersing lens and the said two outer niembera cemented thereto are collecting lenses, one of which has a greater and the other a smaller refnu:- tive index than the dispersing lens situated between them. It is evident that by lueiins of either of these two combinations one of the inner surfaces, or "surfaces of union, ' pro,, are formed by collecting lenses being re8i>ectively concavo-convex and biconvex. In either case the lens Li, being the member nearest to the diaphragm B, is assumed to have the smaller refractive index. The letters r, r^ rj r^ denote the radii of curvature of the surfaces of the lenses, and d, d.^ d^ the central thickness of the lenses. 6 indicates the distance between the lenses and the diaphragm B. There is now no difficulty iu obtaining glass of anitable quality for making achromatic lenses of the kinds required for carrying out the present invention. The practical question as to whether, in a combination of the above description, it is possible to obtain a sufficient astigmatic correction, and, at the same time, to comply with the other conditions required in photographic objectives, lias been answered in the alliriuative by theoretical and practical investigation of lioth types of the new triple lens. Guided by the annexed drawing and the following tables, in which are given the elements of construction of two typical examples, an optician skilled in the construction of lenses or objectives will be enabled to numerically determine or calculate according to known methohotograpliers' roll-holders or slides, has for its object to provide a check against more than one exposure of the same length of film, and consequent spoiling of pictures. The invention consists in providing that the shutter, when replaced after ex- posure of a length of film, is locked and is not free to be again withdrawn until a fresh lengtli of film has been unwound from the feed drum or roller. Locking and unlocking are effected by means of a lever catch pivoted to the body of the roll-holder. This lever catch, which is acted upon at its inner enil by a spring, is shaped at the opposite or outer end to form a wedge-shaped hook, which, when the shutter is locked, engages with a fixed stop provided on the shutter. When a proper length of film has been unwound from the feed roller, an arm attached to the winding indicator passes under a lug formed on the lever aforesaid, and the latter is thereby raised, causing its catch end to become clear ofthestopon the shutter. The shutter is thus unlocked and made free to be withdrawn. In replacing the shutter, after exposure of the film the hooked end of the lever is acted upon by a tongue pivoted to the shutter, and by this means the lever is turned on its pivot to a suflScient degree to withdraw the arm aforesaid out of engagement with the lug. The lever catch then falls and re-engages with the fixed stop on the, shutter. Tlie latter is now looked, and is not again free to be withdrawn until a fresh length of film has been unwound from the feed roller. Improvkmskts jn Plate-changing Devices for Photographic Apparatus. (A communication by Dressier & Heinemann, of -15, Theatinerstrasse, Munich, Germany.) No. 11,149. Wiluam Phillips Thomp.son, F.C.S., M.I.M.E., •6, Lord-street, Liverpool, and 6, Bank-street, Manchester, Lancashire, and 323, High Holbom, Middlesex.— ,4^riZ 22, 1893. In this new plate-changing device, the photographic plates intended for ex- posure are inserted backwardly in the camera, and are maintained against a case by means of a spring attached to the removable back of the camera ; this case may be inserted in the camera from above, from below, or from the sides. This case has, at its lower hinder edge, a slot of such a size that a plate or a firame containing the same may be easily inserted in the case, damp springs, acting against one another, are arranged in this case. The case, when inserted' presses down a sheet spring attached to the bottom of the camera, and bent upwards at right angles, which spring, being released when the ease is drawn out, springs up, and thus, as will be hereinafter described, forms a rest for the plates or frames pressed up against it ; the usual opening of the objective is provided, on which a suitable closing device may be arranged. The mode of working of the improved plate-changing device is as follows :— The plates already exposed are contained in the aforementioned case, those to be exposed in the sjwce behind the same. If the front one of the unexposed plates is to be expo.sed, the case is simply raised up. A prqjecting part of the cose, or other suitable device, prevents the case being entirely drawn out. The following takes place when the case is drawn out : — Firstly, the spring attached to the bottom of the camera springs up, which was hitherto lield down by the case, then the plates in the chamber are pressed forward by means of the spring, so that the front one, which previously rested against the hinder wall of the ease, now stands with its lower part against the curved uppart of the ipring, whilst, at the top, It rests against * projection formed by the bottom of the case. Thereupon, if the objective shutter ha re- moved, timed or instantaneous exposures may take place, and then the case is pushed back again into the camera. The foremost plate, which has just been exposed, thereupon passes into the case through the slot in the same, where it is held by the two springs, and places itself at the back of the plates already contained in the case. The two springs, or their points of contact, press against one another in such a way that the plates entering tlie case are pushed slantwise with their lower ends projecting forward, in order to keep the slot free for another plate to enter. The unexposed plates are pushed slightly backwards by means of the tapered surface of the back wall of the case, when the latter is inserted, ani^ the plates again rest against the back wall of the case. If a fresh plate is to be exposed, the above-described process is repeated. Improvements in or rkl^vting to the Manukacture of Sessitisbd Films FOR Carbon Printing. No. 11,254. Joseph Th.icher Clarke, 3, College-road, Harrow, Middlesex. —ApHl 22, 1893. In carrying out this invention I may conveniently proceed by using the apparatus set forth in the Eastman Patent, No. 19,896, of 1889, and carrying out the process set forth in the Eastman Patent, No. 19,897, of 1889, luid I produce gelatino-carbon films of the usual kind made of gelatine and colour- ing matter, with the optional addition of soap, dextrine, or the other iiiateriali-: commonly used in the trade. When the film is to be sensitised in the manu- facture, bichromate of potash is added. In manufacturing such carbon films it has been customary to place the film upon a backing of paper, and after the exposure, which renders portions of the film insoluble, to dissolve out the remaining portions. As, however, this method produced the insoluble surface or image upon the outer side of the film, it was necessary to transfer the entire film to another backing, after which, on removing the original paper supports, the prints could be obtained by treatment with warm water in tlie well-known manner. In carrying out my invention, instead of employing the paper .supports, 1 form such support of a film of celluloid or transjiareiit in.soluble gelatine, suffi- ciently thin to allow of tlie image being received by the sensitive material through said film. The film is ready for use without the necessity of trans- ferring it to any other support or removing the original support, and the soluble portions of the gelatino-carbon film may, after printing, be removed by washing in the usual manner. A further advantage of the method is that the image it not reversed as regards right and left, as i.s the case in the transfer process. Having obtained the carbon image upon the celluloid or insoluble gelatine support, the picture may be mounted upon cardboard of suitable colour, or upon glass, if it be intended to be seen as a transparency. I do not bind myself to use only "carbon" as the pigment or colouring matter of tlie film, neither do I restrict myself to the subjects of the before- mentioned Patents, Nos. 19,896, 1S89, and 19,897, 1889, as the invention is applicable to films prepared by other processes. Having now particularly described and. ascertained the nature of my said invention, and in what manner the same is to be performed, I declare that what I claim is : — 1. The combination with a "carbon " or " pigment " film or tissue of a transparent backing, wliereby the image can be obtained through the back. 2. A celluloid transparent backing to a "pigment " film for photo- graphic purposes substantially as and for the purjiose described. meetinsjS of IboctetiejS* MEETINGS OF SOCIETIES FOR NEXT WEEK. Ipate of Meeting. May 29 >, 29 „ 29 „ 30 ,. 30 „ 30 » 30 „ 30 M 30 .. 30 ,. 31 M 31 >. 31 •> 31 .. 31 Jaoe 1 >. 1 » 1 « 1 » 1 » 1 » 1 .. 2 » 2 » 2 M 2 » 2 >. 3 Muoe o< Socieky. OameraClub Dundee Amateur Richmond Birmingham Phuto. Booiety Hackuoy Halifax Camera Club Lancaster Leith Paisley Warriugrtou „.„. Bath „ Buruley Leytoustoue , Photographic Olub , Southport , Birmingham Photo. Sooiety Glossop Dale , HuU Leeds Photo. Society , Loudon and Provincial , Oldham , Tunbridge Wellfl Cardiif , Croydon Microscopical Holbom Leawimrtoa Maidstone Hull Place of Me«tuig. Charing Cross-road, W.C. Asso. Studio, Nethergate, Dundee, Greyhound Hotel, Richmond. Club Room, Colonnade Hotel. 206, Miire-street, Hackney. Springfield Barracks, Lancaster. 165, Constitution-street, Leith. 9, Gauze-street, Paisley. Museum, Bold-street, Warrington, Roy. Lit. & Se. Inst.,Terrace-walka. Bank Chambers, Hargreaves-street* The Asi^embly llooms. High-road. Anderton's Hotel. Fleet.8treet,B.C. The Studio, 15, Cambridge-arcadc; Club Room, Colonnade Hotel. 71, Prospect -street^ Hull, Mechanics' Institute, Leeds. Chamiuon Hotel, 15, Alderssatc^* The Lyceum, Union -street, Old ham. Mechanio«' Inst., Tuubridge WeUff. Public Hall, George-street, Ck-oydon^ Trinity Church Room, Morton-st. "The Palace," Maidstone. 71, Proepect-street, Halt 1/f^ '20, 1893] THE BRITISH JOUKNAL OF PHOTOGRAPHY. PUOTOOUAPUIC SOCIETY OF GREAT BRITAIN. Ma» a Technical MectiDg, Mr. Horace Wiliuer in the chair. Tklei'Hoto Lbnsks. Mr. G. Houghton exliibited tlio new telescopic len.f, which wc described last week, also examples of enlarged photographs produced by it. Mr. T. liOLAS .said that one of the examples showed slight curvature of the Held, and asked Mr. Dallim-yer whither, m his tde-photo lens, ho had dis- carded the rcctiliniar Un.s as the ^imary lens on that account. Mr. T. K. D.vLi.MKYBK said that two years ago he had adopted a form of the tele-photo lens having a single positive and a triple negative. With a single form it was ini possible to correct it for the excentrical pencils throiighout the field. He had sucniiU'd in doing so, but it gave phicusliion distortion and aberration towards the edges. In tlie later form, knowing that the front Icus was corrected, it was impossible to correct it throughout tlie tield with a single combination. To obviate the drawback of having to correct the excentrical pencils, he eventually decided upon a lens convex on both exterior surfaces, in conjunction with a particular tyi)e of portrait lens. The reason for that was that if the sejwnition was correct for a certain distance, and the positive element be moved, the correction for spherical aberration could not be perfect. In that particular form of portrait lens the correction was perfect for a near object, and if the magnification was moderate those aberrations existing in a marked degree on a high iiower did not manifest themselves. The lens sliown by Mr. Houghton was identical with one described by Steinheil, who employed an antiplanat. The positive element gave a rather pronounced curvature of the field towards the lens, the triple negative employed producing the opposite curva- ture. This tlatteued the field, but the lens still gave prismatic excentrical pencils. The instrument shown wa.s not of a powerful nature ; with a weaker negative he should have expected that the constructor would have made it much more rapid. He had been through this particular construction, and had discarded it on account of its diliiculties ; although stopped down for landscape work, it was, no doubt, a valuable instrument. The Dagdbbbeotype Process. Mr. W. England prefaced a demonstration of the Daguerreotype process by a brief description of it and the exliibition of a number of examples, a collec- tion of wliich was on view in the Society's rooms. Mr. England said that the )ioIisiied silver plate was first treated with tripoli and the buff, and then sensitised in a box for that pui'pose with iodine and bromine in the order named, and finally with iodme, when the plate appeared of a steel-blue colour. Considerable skill w.as re(|uired to get tlie exact tint. If the plate was accidentally exposed to light, treatment with iodine would restore it. The exjiosure required was about double that of wet collodion. Development ■was affected by exposure to mercury vapour at 120° Fahr. for seven to fifteen minutes. The picture was fixed and gilded over heat in a solution as follows, the brilliancy and beauty of the image depending on the success with which this operation was carried out : — Gold chloride 15 grains. Distilled water 16 ounces. 2. Hyposulphite of soda i drachms. Distilled water 16 ounces. The solutions being mixed by pouring the hypo into the gold. After the gilding, tlie picture is washed in distilled water and dried over heat. Mr. England theu went through the practical pail of sensitising a plate, developing an exposed plate, fixing, gilding, and drying, passing round two portraits made in this manner, which were highly admired. He said the pictures were the first he had taken for twenty yeai-s. They had had a minute's exposure in a glass room. In reply to a <[uesticm, he said the mercury was fixed under the gilding. If a D.agueiTeotype got tarnished, it should not be rubbed, but should be cleaned by flooding it with alcohol, rinsed in water, and placed in a weak solution of cyanide, five grains to the ounce ; for bad cases of tarnish a strength of ten grains to the ounce might be used. It should finally be washed in distilled water and dried over heat. To tell whether a Daguerreotype was gilded or not, let the comer be rubbed with something soft, and if it were not gilded the mercury would come away. The Iarge.Ht Daguerreotypes made were probably l.')xl2, by Mayall. Mr. W. E. Debknham mentioned that he had employed pure hydrochloric acid for removing tarnish. Mr. J. TUAILI. Taylor said he had practised the Daguerreotjrpe jirocess a gooer cent. In the course of further remarks, Mr. Taylor said a piece of silvertil gla,ss for the purpose might be cheaply made by porchaning a small piece of looking-glass and reiiioviug the lucking with benzole. A vote of thanks was passed to Mr. England for his paper and demouitra- tion. Mr. H. A. Lawranck said that in his paper on the work of the Congresses, Mr. Warnerke had referred to a suggested mcthotl of determining the sliced ol jilates by the changes of colour they underwent in light. He exhibited several strips which had been exposed to sunlight and had discoloured, and asked for information on the point Some discussion took place, but no information was elicited. LONDON AND PROVINCIAL PHOTOORAPHIC'ASSOCIA'TrOK^ MAy 18, Mr. Charles U. Oakden in the chair. Mr. S. G. B. Dicker was elected a member. Edwards' Varnish. Samples of Messrs. B. .J. Edwards & Co.'s cold varnish for plates and flims' were distributed among the members. Mr. W. H. Barnes exhibited a film negative that had been vi^raished with the varnish, and had been in u.se for printing purposes five months. Mr. Cowan subsequently treated a plate with the varnish, which dried very quickly. The Lombebo Plates. Mr. J. S. Teape passed round two negatives made on the Lomberg plates distributed at the previous meeting. They were exposed in Epping Forest at six o'clock in the evening for three and ten seconds respectively with/-24, and developed with pyro-ammonia. The exposures were about correct, and the negatives were of good quality. Silver in Dry Plate.s. Mr. P. EvEBlTT allnde4 to the recently published results of a French experimentalist who had given the quantities of silver contained in commercial dry plates, and asked Mr. Haddon, who had jiromised to undertake a similar series of experiments, whether he approved of the method adopted. Mr. A. Uaudon disagreed with the method employed, and promised soon to start on his experiments. Astigmatism. Question from the box : '■ What is Astigmatism i" Mr. W. E. Debenham said it was a difference in the focal planes of rays of light which pass from the margins of the field, and are brought to a different plane of focus by different parts of the lens. P. 0. P. .Mr. R. Bkckett exhibited a portrait print on P. 0. P., which had been ex- posed to light for about two months, one pai-t having been covered up. The jiriiit seemed to have gained in colour in the covered parts. A Spray Producer. Mr. Jameson, in connexion with the demonstration of the Air Brush, given some months ago by Mr. Harrison, exhibited a spray producer, the liquid being forced out in the form of a jet by blowing througli a tube. Patterns could be made on paper by the use of a stencil jdate. For making sensitised paper, he thought the instrument would answer perfectly well. Being a Lantern Night, slides by Messrs. Cooke and Freshwater were shown. North London Photographic Society.— May 16, Mr. W. Bishop in the chair.— Mr. Herbert Fry lectured on The .■imde.U Plate.— A collection of prints from negatives on these idates was exhibited, and evidenced that the claims advanced in respect of them were well founded. The long scale of gradation and the freedom from halation were most remarked. Mr. Fry, in reiterating the fivefold advantages belonging to the plate, a statement of which has, more than once, been communicated through "the usual channels of public infoimation," said that the multiple-coated plate was not put forward as the be-all and end-all of photography. The use of it would not make every novice a medal-taker, and it could be misused. But the introduction of it had put a better tool in the hands of the careful worker than coidd be obtained heretofore. If any one thought he could go one better, the sooner he did so the better for photography. Mr. Fry explained the tentative mode of develop- ment best adapted to get good results out of the plate, and inveighed strongly against the practice of using any developing solutiou more than once. The plates could bo intensified or reduced in the usual way, but these processes were only necessary when there had been a slip in the development. In con- cluding, he warned his audience not to follow in the wake of certain experi- mentalists, who advised wilful over-exposure, followed by stripping off the top film. A vote of thanks was passed to Mr. Fry for his lecture. Hackney Photographic Society.— May 16, Mr. R. Becketfin the chair.— The Hon. Assistant Secretary announced that the attendances at Wanstead Park the previous Saturday amounted to twenty-one. From the question-box : "Wanted, a cure for pinholes." The Chairman gave a description of pin- holes as absence of films and silver, dust, and air-bells, and fragments of glass. Mr. Hknsler said he used a deep dish, and gave the plate a sharp knock on the side when developing. Mr. S. J. Bbckbtt said Indian ink was about the best thing to use if pin-holes were caused. Mr. Hensler could not dissolve the metabisulphite of soda as recommended by Mr. Dres.ser. Messrs. Nl'nn and Fexton Jones had found no difticulty in doing .so. Mr. Moobe asked how to clear a negative from green and red fog. Mr. Sodeau said Captain Abiiey re- commended to convert the whole of the silver into its haloid condition, and 334 THE BKITISH JOURNAL OF PHOTOGRAPH X. [May 26, 1893 redevelop. Bromine water would convert, or ferric chloride. The conversion is to a grey fog, which does not matter much. Mr. T. H. Smith asked cause and cure for iridescent marginal stains on plates. Methylated spirit on wash- leather (to rub on plate) will remove it easily. Mr. W. Teuton Jones then proceeded to open the discussion on Plates versus Fihis. He spoke of great portability in Hlms, and use for carbon work— advaalages over plates. Good for-clouds, as they would print either way ; are said to be free Irom halation. On the other hand, one thing which had done much to retard the progress was faulty emulsions, and tendency to curl when developing. Incidentally he said Mr. Dresser had overcome this by the introduction into his developing tray of a square, heavy framing, which rested on the rebate, and caused films to lay flat. A question that occurred was, " When developing, will films stand heat?" Mr. Sodeau explained an Eastman roll-holder, and said he rather favoured films, had easily worked his ; said the films were well •coated, and, by wetting his dish first, easily got them to lie flat. Mr. Hensler Jiad taken out films to New Zealand, and found them a great advantage. Mr. A. Barker had some good films, but others were bad. Mr. F. Houghton ■used them in the Frena with good result, but some of the bits of film had at times blistered or floated oS. Mr. GosUNo asked, " Were films advisable for a beginner ?" Mr. S. J. Beckett said, " No," and generally objected to films ; had thirty-three and one-third per cent, failures on films to five of plates. Mr. TouLSONsaid, in larger sizes there was a danger of backing. Mr. W. Fenton Jones said he had found film emulsion sometimes thin, and gave, as a test for thinly coated plates, the holding of one before a gas flame, and, if the flame could be seen through, it obviously showed thin emulsion. The Chairman had not found films prevent halation, as had been stated. Putney FbotogTapliic Society. — May 18. — The members travelled to Woking, and from there proceeded along the Basingstoke Canal in the direc- ■tion of Byfleet and the Wey Navigation. As there was a bright diff'iised light, a number of good negatives were obtained of the beautiful scenery along the Tonte, additional interest being given by the grouping of a few children, which •the leaders had previously engaged to meet the party. Slclunond Camera Club. — March 15, Mr. Ardaseer in the chair. — The Pre- sident (Mr. Cembrano) delivered a lecture on Architectural Photography. He ■^vided the subject into three broad divisions — Apparatus, Process, and Sub- ject. Under the first head, tripods, cameras, lenses, and accessories, such as focussing glasses, levels, and tlash lamps, were fully dealt with ; under the second were considered plates, exposure, and development ; while the third -comprised hints ae to the choice of subject, whether exteriors or interiors, lighting, and pictorial effect. The lecture was of a most practical nature, and, by way of illustration, some of Mr. Cembrano's well-known architectural pictures were throvra upon the screen, the lecturer remarking that there was no more suitable and effective mode of showing photographs of architecture than through the lantern. Brixton and Clapham Camera Club.— -May 16, the President (Dr. J. Reynolds, F.R.G.S.) in the chair. — Mr. W. Thomas read a paper on A Photo- graphic Picture, and Some Notes on its Production. The paper dealt fully •with composition, light, and shade, balance, printing in clouds, printing pro- -cesses, use of stops, mounting and framing. The lecturer's remarks were illustrated by numerous specimen pictures and blackboard illustrations. Mr. Thomas himself used cold-bath platinotype paper for his pictures, and strongly .recommended its adoption by his hearers as being exceedingly simple to use and beautiful in its results. He advised members to lay in a large stock of cloud negatives, and said that great care should be taken, when printing in .clouds, to see that the clouds were lighted in the same manner as the landscape itself. Considerable discussion took place at the conclusion of the paper, and, in answer to a request, Mr. Thomas promised to take the members out for a ■practical lesson in the field, in order that they might put his principles into practice under his supervision. Ashton-under-Ljme Pbotographlc Society.— May 12 to 15.— An exhibition of over 10(J photographs of the land of the Broads, lent by the Great Eastern Railway Company, who have a great number of these views in their railway ■carriages. The photographs were inspected by a large number of members and •friends with very great interest, and many expressed their desire to visit the places depicted. Many also said they should visit Norfolk with the camera ■so the Society may expect to see more views before very long from that most ■ delightful county. Oosport PbotograpUc Society.— May 16, Mr. W. B. Smith in the chair.— ■Mr. Bblton, of the Paget Prize Plate Company attended, and gave an instruc- tive demonstration on Printing-out Opals and Plates. The specimens handed round were much admired, and at the conclusion of the demonstration Mr. Belton was thanked for the able manner in which he had dealt with his sub- ject. During the evening the Chairman announced that the Rev. E. Paske- Smith had been elected to a vacancy on the Council, and that Mr. Reginald E. ■Green had been chosen joint Hon. Secretary. The Chairman also presented Mr. T. E. Williams with the silver medal, and Mr. A. Fisher with the bronze medal, won in the late National Lantern-slide Competition, and congratulated rthem on their well-merited success. ' C&rrespondenln should twrer write on both sides oj the jtaper. No notice is tak«n of communtcationi unlea the namet ond addreaiet of th« writers ore gioen. THE CONCENTRIC LENS. To the Editob. 8», — I note the letter of Mr. F. H. Burton, ai to which I haye a few 'Words to say. His pretended inference that " Mr. Stillman makes 10 x 8 negatives with an eight-inch lens, attached to a camera ■with a cracked front , and cuts out the centre of his prints," those I have seen. Their insignificant weight is a great thing in their favour. Personally, being of somewliat lazy habits, I have never carried anything larger than a 5 x 4 hand camera on any fatiguing expedition. But I leave such details to the sundry writers who have already given us valuable rorinklce on traveller's work. — I am, yours, &o., Easterton, Parkgtone, R.S.O., Dorset, May 20, 1893. MARSHA1.L TTat.t., » c-REGULATORS. To the Editor. Sir, — In reference to R. R. Beard's communication in yours of the 12th, I really do not know what he means, as I never mentioned "_tiOO lbs. pressure," " lubricant," or, '• fatty matters," and the drawing' of the apparatus I sent him, instead of only four inches, has a possible pressure of thirty inches, and I have never seen a lime that would stand thirty inches of water pressure. What have I to do whether gas compressors, favour or condemn the use of grease ? Then he begins to prophesy about the failure of my anti-friction cock.^thc construction of which he is wholly ignorant of; then he advises me to get a cylinder of compressed gas^ Really, if Mr. R. R, Beard has any friends, they should keep an eye on him. According to published evidence, I am the first person who ever used[a ■ regulator for the limeUght. In conclusion, let me say that a man may be able to make clear to other minds what is clear to himself, but it is very difficult to make clear to others what is not clear to oneself. — I am, . yours, &c. William Birbeu,. Airdrie, May 22, 1893. THE PHOTOGRAPHIC SALON. To the Editor. Sib, — As chairman of the Organizing Committee of the Exhibition or Salon of photographic pictures, to be held at the Dudley Gallery next October, may I say a word to correct the impression that there is in- tention to clash with the usual Exhibition of the Photographic Society? The same reason which actuates the Photographic Society in selecting the autumn compels us to take about the same period, and that reason is the difficulty of obtaining a suitable gallery at any other season. We certainly intend to have the best possible picture exhibition, but not to intrench on the usual lines of the Photographic Society, nor in any way to form opposition. Assurance on those points may be gained by a reference to the influential list of our Committee ; and, further, it may be pointed out that, with one exception, all the Judges at the Photographic Society's Exhibition are prominent members of the Salon organization. The two Exhibitions will probably be complementary, and even • mutually helpful, by taking place at the same time. — I am, yours, &c.. May 20, 1893. Gboboe Davmojj. ♦ iSxcftangc OTolumn* *,* No charge is made Jor inserting Exchanges of Apparatus in this column ; but none will be inserted unless the article wanted is definitely staled. Those who specify their requirements as "anything useful" will therefore understand ' the reason of their non-appearance. The full name of the advertiser must in all cases be given for publication, otherwise the JExchanges will not be inserted. Dnllmeyer'B 2b, in perfect order, offered in excfaanf^e for cabinet lens of longer fooas or for a 3d, Uoss* Universal or oilier rapid leua of abont ten-inch focns. — Address, . H. Pariow, Hythe, Kent. Eois' 10x10 Spanish mahogany camera, complete, long fooassing screw, as new, cost 81. ; exchanf^e for light-pillared balnstrade or ^ledostaL — Address, J. HOBTOS, Central Photographic Studio, Garoline-Btreet, Cardiff. Wray'»8Jx6i view lens, / 8, twelve-inch focns, also Thomton-Pickard special double blind shutter to fit above lens, woiks to onc-two-hnndredth of a second ; exchaug« for quarter or half-plate set Cash adjnstmeot.— Addr«s«, J. Bkssabdi lUl, Gold- - liaffk-road, W. THE BKITISH JOURNAL OE PHOTOGRAPHY. [May 26, 1893. an0toet!5 to OTorrcspottUcntsJ. * * All matters intended for the text portion 0/ ttw Jotonal, including 'tn^ertnd Exchanges, must he addressed to'' The Editor, Thb British S^NAL OF PHOT(^RipBT," 2, York-street, Covent Garden, London In- attention to this ensures delay. * Cm-respondents are informed that we cannot undertake to answer com- ^municcUions through the post. - • Communications relating to Advertisements and general busiv^ affairs "should le addressed to Messrs. Hbnby Qbbenwood & Co., 2 York-street, Covent Garden, London. E_ N. D.— The gold can be precipitated by a solution of protosulphate of iron. H. SnsMANN.— The addrea* is Harrington Bros., Shaudon Chemical Works, Cork. Frank Osbornb.— Better mix the colouring matter with varnish, and apply this to the slides. Perplexed.— Information as to mounting gelatino-chloride prints is given in our "Correspondence" columns this week. L. Clay. Your only course is to proceed against the shopkeeper in the County Court for the value of the picture. LiVBRPOOL.— In selecting a caniera-staad, bear in mind that rigidity is the primary consideration, and portability and lightness a secondary one. W. G. Honey. — 1 . The idea is a useful one, but not, we think, patentable. 2 Communicate with the Prisons Department, Home Office, Whitehall, 8.W. Dr. J. H. Smith & Co. (Zurich).— Messrs. S. Guiterraann & Co., 35, Alder- raanbury, E.C., advertise celluloid in the sheet and roUable form for coating purjioses. W. Cope.— The markings are doubtless caused by impurities in the mounts— we have seen many similar cases. Without analysis it is impossible to indicate the precise cause. r. G. Hill. — It depends upon the nature of the backing whether the stains on the front of the negative caused by it can be removed. If it is soluble in water, it probably may not be difficult to do so by prolonged washing. L. Voss. — No work is published on dark rooms and their fittings, and none is required. Every one fits up his dark room according to his taste or require- ment, or, we might say, more often than not according to the space or apart- ment at command. Jl. C. Goddard.— What matters the appearance of the solution so long as it develops well ? The slight discolouration was, no doubt, caused, as surmised, by the stopper being left out of the -bottle for several weeks. Certainly the pyrogallic acid must not be blamed. IE. MoOKE. — The positive process is usually worked with collodion. Dry plates for the purpose are supplied by Mr. Jonathan Fallowiield. Formulaj for working are supplied with the plates. Any of the dealers in photographic goods will supply dark tents for any purpose that may be required. 'Ghas. Kebr (Colombo). — 1. We are much interested in the photographs of races, which are very good. 2. Probably Mr. Spooner, of the Strand, could obtain photographs of the finishes of races for you. 3. ,We know of no shutter faster than the one you mention. At present one-five-hundredth of a second is probably the greatest rapidity of English shutters. T. Marks. — 1. A half-plate portrait lens will do quite well for enlarging from quarter-plate negatives ; indeed, it will be better than the quarter-plate wide-angle rectilinear. 2. In working with daylight a condenser is quite unnecessary. 3. In making enlarged negatives, ordinary plates will do quite as well as the more rapid ones : in fact, we should prefer them. K. W. — There is no mistake in the matter. Glycerine mixes perfectly well with alcohol in all proportions. It may be added to collodion if necessary. Castor oil will also mix with collodion, and generally is contained in the collodion used for enamelling prints. If you are so dubious iu the matter, why not make an experiment or two to satisfy yourself on the point .* T. Banks sends us some prints, and complains of their lack of sharpness. He says he is working with a fixed focus lens, and asks whether the fault rests with the lens, or the shutter not working quick enough ? — It is quite clear that the lens is not set to the right focus. There appears to be no fault with the shutter, as the moving objects are quite as sharp as the brick walls and houses. •Constant Rkadbe. — There is nothing to hinder you from taking out the patent yourself. The next time you are in London you can obtain the requisite forms, free of exi>ense, on applying at the office adjoining the east front entrance of the Law Courts. You may also apply at the Post-Oflice of your village, but it is doubtful whether you can obtain them in such an unimportant place. T. C. H. — It is impossible to give any idea of the cost of building a studio on tJie top of a house, and a staircase up it, simply from the dimensions given. It often happens that the structural alterations of the main building to re- ceive it, and the approaches to it, entail a much greater cost tliau the .studio itself. We can only suggest that you prepare plans of what is required, and then submit them to one or more of the local builders, who will give an ■estimate for the work. C. B. writes : " Can you give me information respecting Switzerland ? Are the Custom-House officers likely to examine your plates ? Is it necessary to get a pass, if so, from whom ? ' — Perhaps some of our readers will supply the desired information. No passport is required for Switzerland, but in all cases when travelling abroad it is well to be provided with one. It may sometimes be the means of avoiding trouble. R. A. J. — The lighting of the ))ortrait is very good so far as the dominant light is concerned, but the shadows are much too heavy. This may in future be remedied by using a reflector to soften them. A white sheet, or a few news- papers on the domestic clothes-horse will answer admirably. With judicious management of the light, quite as good portraits are to be obtained at a large bay window of an ordinary room as in the orthodox studio. Trfko writes : " We are having the electric light cable laid down here. What candle-power arc lamps (or other lamps) shall we require for lighting studio ? Who could you recommend to fit it up ? Would it coat over 40/ ! — A light of five or six thousand candle-power will do. Messrs. Gwynne A Co., Brook-street Works, Holborn, make a speciality of electric lighting plant for photographers. Better write to them for an estimate. Cypher says : "I had some negatives out printing, and a shower of rain came on, and wetted the frames. They were wiped, and put away tUl next day to fmi;iih printing. On opening the frames, I found the paper had stuck to the negatives, and, on pulling it off, the film pulled away in places, and the other parts are stained. Can anything be done to remedy the evil ?" — No, except to make fresh negatives from any prints that may be iu existence. A. S. King. — If you imagine that you are going to obtain sharp negatives of interiors of cathedrals with a hand camera, if the camera be held in the hand, you will be greatly disappointed. If, however, the camera be used on a stand or other rigid support, then a hand camera will answer i)erfectly well. Pictures so obtained cannot be styled hand-camera work, and to enter it as such in any competition would not be fair. 0. M. says : " In trying the experiment of making chloride of gold, as describsd in last year's Almanac by G. W. Webster, not being able to get a digester, I used a white porcelain jug, with the result that all the gold — twenty shillings' worth — is gone into the jug. What do you advise to do with it ? Is there any way to separate the precious from the vile ? I have succeeded perfectly since by using an oil flask." — It is difficult to see, if a vorcelain ing were used, how the gold could get into the ware. Probably, nowever, the jug was common earthenware. If the gold is still in the ware, it ought to be recoverable. Probably the most practical way will be to reduce the jug to a fine powder, and send it to a refiner. Photographic Club.- May 31, The Daguerreotype Process. June 7, Plates versus Films. London and Provincial Photographic Association.— June 1, Angle of View, paper by Mr. P. Everitt. The studio of Mr. Vandyck, of which we made mention last week, is situated at 20, Ladbroke-grove-road, Netting Hill Station, W. Liverpool Amateur Photographic Association. — Mr. J. L. Mackrell has consented to give a practical demonstration on Enlarging, &c., on Wednesday, June 7, from twelve to half past one, and on Thursday, June 8, from one to half past two. Excursion, Saturday, May 27. Bebington, half day. Leader, Mr. G. A. Carruthcrs. Train leaves James-street Station (Mersey Tunnel) at fifty luinutes past one for two. Amatkdr Photogbai'Hic Society of Madras. — The first Open Exhibition of Photographs will be held in a suitable hall iu Madras during the month of December, 1893 ; it will remain open for a period of one week. All exhibits must be in the hands of the Hon. Secretary by December 1, and all charges for carriage to and from the Exhibition must be paid by the exhibitors. AH ex- hibits should be clearly addressed to the Hon. Secretary, Amateur Photo- graphic Society of Madras, of whom full particulars of classes, kc. , may be ob- tained. The followingclasses are : — Open to the world, Class A. — Silvermedal. for the best set of four landscapes ; silver medal, for best set of four flgnre subjects ; silver medal, for best set of twelve lantern slides ; silver medal, for the second best enlargement ; bronze medal, for second best of each of the first three 'subjects. Open to amateurs only, Class B. — Silver medal, for the best photograph, any subject ; bronze medal, for second best photograph, any subject ; silver medal, for best set of four figure subjects ; silver medal, for best set of four other than figure subjects ; bronze medal, for best set of six lantern slides ; silver medal, for best enlargement ; silver medal, for best set of hand- camera shots ; silver medal, to be awarded by Judges for any exhibit of special merit not included in the above classes. OONTIBNTS, Facm notice — pictorial supplements to -the BRITISH JOURNAL OF photography" 821 DAGUEBUEOTYPING REDIVIVUS SU THE PERFECT FIXATION OF NEQA. TIVE8 322 PHOTOOUAPHY AS A BUSINESS PAST AND PRESENT 323 MM, LUMIERE'S EXPERIMENTS IN ••COLOUR PHOTOGHAPHY" SK tia» AMERICAN NOTES AND NEWS .S25 MEIOL. By W. B. BOLTON. .j sas JOTTINGS. By COSMOS SELECTIONS. By EDWARD DUNMORE i COMPOSITE HELIOCHROMY. By F. H. rvES ass MARIONS NEW SItMMEB AND SEA- SONABLE NOVELTIES I RECENT PA'I'ENTS Ul MEETINGS OF SOCIETIES 932 CORRESPONDENCE 394 EXCHANGE COLUMN 385 ASSWBBS TO CORRESPONDENTS 336 THE BRITISH JOURNAL OF PHOTOGRAPHY. No. 1726. Vol. XL.— JUNE 2, 1893. WHOLE-PLATE BINOCULAR PICTURES, AND HOW TO SEE THEM. It is well recognised that, the farther tlie eyes of an observer are apart, the greater is the increase in the perception of the varying distances of objects. By way of experiment we, some twenty years since, constructed an instrument by which the •eyes were effectively separated a distance of twelve inches, and the effect obtained, while exceedingly instructive, bordered on the ludicrous, especially when the subjects examined were situated at only a moderate distance. But this increase of base gave to distant objects a real charm, inasmuch as the effect of solidity, by which all objects near at hand and seen by both eves are characterised, was extended to those situated at a great distance. Arising out of a number of desultory experiments entered into at the time was a telemeter, by which tlie distance of any •object within one or two miles of the point of o)jservation could be ascertained with approximate accuracy for those most distant, while, for tliose nearer at hand — say about half a niile — the accuracy was sufficient to enable the sighting of a rifle to be effected. We may some day publish this as a •useful adjunct to the employment of fixed lenses of longer range than is usual. By a principle analogous to that by which the previously expressed ideas were carried into practical effect. Sir Howard Grubb had it applied to the examination of stereoscopic pic- tures exceeding in dimensions those of the usual Size, and we willingly accord to this gentleman the credit of tliis applica- tion. It is now known to every intelligent reader of stereo- photographic literature that, in order to the comfortable ex- amination of binocular pictures by one of the ordinary stereo- scopes now so readily obtainable in commerce, the pictures should be mounted at a distance apart not exceeding three inches. Now, three inches is a size of picture (frem side to side, for there is no fixed limit to its iieight) that does not give satisfaction to every one, even when viewed tlirough eyepieces from six to eight inches in focus. Bearing in mind the Grubb principle enunciated two decades ago, and its capabilities, we have constructed, by means pre- sently to be described, a stereosco[)e ([ualified to show dis- tinctly, from centre to margin, a stereoscopic print of somewhat enormous size, seeing it is composed of two whole-plate photo- graplis placed side by side on one sheet of board. Now, seeing that the centres of the elementary pictures composing this monster stereogram measure six and a half inches apart, the height of each being eight inches, the bringing of these into .coalescence evidently cannot be efifected by a prismatic or lenticular stereoscope of the usual form. Those acquainted with Wheatstone's stereoscope are aware that in this instrument the pictures were large, but they had to be mounted on separate boards and had to be inserted facing each other at the opposite sides of a large box, or, at any rate, a framework, capable of holding them in this position. They were viewed by two small mirrors, one opposite to each eye, but inclined at an angle of forty-five degrees, by which, when the eyes were directed straight forward, they saw the pictures that were mounted at the sides of the box quite stereoscopicaUy, but reversed as regards the right and left of the picture. Now, let it be remembered that our pair of whole-plate photographic prints are pasted side by side upon one mount, that they are non-reversed and that their centres are six and a half inches apart. In order to bring each eye virtually oppo- site the centre of each print, two small mirrors must, as in Wheatstone's stereoscope, be mounted diagonally, one opposite to each eye, and at three inches apart. A second pair of mirrors must next be mounted, each parallel, or nearly so, to the first pair, and at a distance of one inch and three quarters from the surface of each. These second mirrors must also be rather larger than those nearest the eyes, else will not the whole of the print be seen. With a pair of prismatic or even ordinary simple lenses in front of the eye tlie stereoscope is completed. What is imperative is, that the mirrors be silvered on the front surface, by depositing thereon metallic silver by one or other of the methods described in so many of our Almanacs, and which need not here be recapitulated. The way to do it is to select a piece of patent plate, and, having cleaned the best surface, deposit the silver on it, and then, when dry, cut pieces the right size from it by a diamond. Sir Howard Grubb's system of employing diagonal prisms, instead of mirrors, to cause the rectangular alterations of the path of the light is to be commended on account of its elegance ; but it is objectionable on account of its necessarily high cost, for the glass of which the prisms are formed must be very pure and free from defects. We have sought to con- struct analogous ones of water by enclosing the fluid in a square tube, the ends of which were cut to an angle, and covered by cementing thereon with pitch squares of selected small pieces of glass, each of the square tubes employed being cut open to permit of small squares of glass being let in at opposite top and bottom ends, so as not to interpose any opaque matter which would bar the passage of light from the picture to the diagonal end pieces, and thence to the eye. Those who have the patience and mechanical skiU to construct such a substitute for the prism will be well rewarded for their pains, for not only will it serve the special purpose for whieh it was made, but it will also answer for inspecting distant 3^8 THE BRITISH JOURNAL OF PHOTOGRAPHY. [June" 1893. objects — the prismatic eyepiece being removed — and seeing tliem under the circumstaDces alluded to in the opening sentence of this article. It is not necessary that the whole-plate picture of which we have spoken he taken direct, for an enlargement obtained from tlie negatives, takeu in a stereoscopic camera of the usual size, will serve the purpose equally well, for poor indeed must be tiie negative that will not bear being enlarged to two diameters, all that is necessary for the purpose now advocated. OUTDOOR GROUPS. The present season of the year initiates a period during which a vast amount of photography covered by this title is under- taken. Much of it is so capable of improvement that a short discussion upon the subject may lead to a fuller understanding of the conditions governing or limiting success. We do not propose to discuss it from an artistic standpoint, for that has been very completely done before ; the mechanical aspect would, perhaps, describe best the mode it has been least treated. Naturally the lens comes in for first consideration ; and liere, at the outset, let us say we have no intention whatever of singling out a particular maker as supplying the most suitable article. As need not be here said, any lens will take a group ; but for general use a landscape lens gives too curved and limited a field, and an ordinary portrait lens too limited a field, hence choice will be confined to one or other of the many symmetrical or rectilinear types of instruments. But, as groups have so frequently to bo taken under conditions requiring very short exposures, it is evident that a lens wh(jBe aperture is f-16 would frequently be put out of court, and an objective "pur- chased specially for group-taking would advisedly be chosen from the doublet type capable of being worked at f-7 or /-8 at will. For important groups, however, /-12 or /-16 will be the most probable aperture, for not only has flatness of field to be considered, but depth of definition. Makers vary much in their statements as to the covering power of their instruments but, broadly speaking, it would be wise, in selecting a lens, to choose one with a focus, at the very least, of about one-half longer than the longest side of the plate it is to be used for. There are lists before us in which sharp covering power is put down at all proportions, from a plate as long as the focus down to less than the proportion we recommend. So much depends upon what is looked upon as sharpness. A degree of definition that would be excellent in a landscape would be very imperfect in a group where, for instance, the figures were not more than an I inch high. We therefore very strongly recommend any lens- purchaser to see the lens itself rather than be guided by the dimensions of covering power as given in the printed lists. We do not here for a moment impugn the good faith of the makers —we draw attention to the need of understanding thoroughly what is meant by covering power. There is another reason for choosing a lens of long focus in comparison with the size of the plate, and that is the curvature of the field. The nearer an object is to the axis of the lens, the less is this curvature perceptible ; but when, say, a twelve- inch focus lens was used for a twelve-inch plate on a group, of people raised, for example, on a long terrace, it would require a very small stop indeed for those sitters who came near the edge of the plate. We must not be understood as suggesting tiiat this benefit from a small stop is produced by its flattening the field, we need scarcely say it would not do ao ; but the depth of definition would be so increased by the small pencils that the departure from exact focus at the edge would not then be noticed. With, however, a lens of focus double or even half as much again, curvilinear distortion would be far less troublesome. So far as to the lens to be used ; we may next discuss how to use it. A group is arranged, let us say, and the image is noted on the screen. If, as would be natural to do, the sitters are arranged mainly in a straight line, or about a line, it will be too often observed when using the full aperture that curved fields are by no means things of the past, and the sharpness will be wonderfully increased by placing the figures about a curved line. The section of a saucer is often suggested ; but with some lenses, and by good makers, it will be found that a section of a horse-shoe will almost be needed for a ground plan of the group. One word or two on this point will be reason- able. Although a great increase of sharpness is discernible when arranging the group on a curved line, such arrangement is not universally applicable. The further the figures are removed from the camera, the less can the curvature of the field be reduced by this means. Many a photographer who has been in the habit of taking groups of a dozen, or two or three, and managed to his satisfaction in this manner, has been puzzled when he has essayed a hundred or two at once. They cover so much ground that, even if he could marshal them to position, they are so near the distance beyond which all objects are in focus, that to effect curvature by bringing those at the margin nearer to the lens to lengthen the focus at that part would make the whole ridiculous. We dwell upon this point, as it is of such importance when using a lens with fairly lar»e aperture. So far we are assuming that the negatives are to be taken direct of the required size, but it is well worth the photo- grapher's while, when he has large groups to take, to consider whether he should not take his first negative on a small scale and enlarge it afterwards. The enlarging of negatives has now been brought to such perfection that, not to speak of direct bromide enlargements, the results so obtained might be of high-class character. The advantages of such a mode need scarcely b^ enumerated. The smaller the lens used the more likely it is to possess crisp defining powers, and the less per- ceptible will be the curvature of field ; the depth of focus will, with equal exposures, be (the standpoint being the same) far greater; and, lastly, a larger number of exposures can be made, and in more rapid succession than with large plates, while when great rapidity is needed, and there is only one available standpoint, the long-focus lens, giving the same depth as a small one, is placed completely out of court. I The Queen's Plate. — Her Majesty has given permission to our contemporary, the Gentleicoman, to photograph her gold plate at Windsor Castle. The pictures if well reproduced by a photo- mechanical method will prove highly interesting, particularly to lady readers. It may not be generally known that Windsor Castle con- tains a well-appointed photographic studio and dark room that would be the envy of many London photographers, and so would its furniture and fittings. It is here that a large proportion of the Royal portraits have been taken. &elica of Ancient Ziondon.— Another of the old City churches is doomed. This time it is St. Mary's in the MinoriM. Amongst many of the City churches that have been pulled dowa during the past couple of decades have been some of Sir Christopher Supplement. June 2nd 1893. The British Journal of Photography. PMolngf§ A TMfoi A Co.. aenwa . Mtgtilt bf W. Bnolia, Kelgtte. A TOWE^ WA^DE^. (Beef Gate?.) Jim.' -J 18!».tl TIIR niJlTISH .lOUllNAL OF PHOTfVlilA I'll Y. 23^ Wren'8 finest examples. Were photographs of them, externally and internally, taken before they were demoliBhed !- If not, why not ? Swely it is not too much to expect the authorities of the wealthiest city of the world to, in their official capacity, secure, and retain, photographic records of all interesting and instructive relics before they are swept away for ever. That the City does think of some- thiu); beyond business and bustle is evidenced by the fact that since the Oilbert pictures have been at Guildhall they have proved a great attraction, from 700 to 1000 persons a day having visited the exhibi- tion. The City is proud of its ancient traditions and relics. Why do they not perpetuate, by means of photography, the latter, before they are destroyed .'' Photogrraplilc Convention of the TTnlted Klng-dom. —The Kight Worshipful the Mayor of riymouth, .Mr. W. Law, will open the proceedings on Monday, July 3, at the Western Law Courts, the Guildhall, after which a conversazione and a lantern «>ntertaiument will be given. On the Wednesday the group will be taken in the Guildhall Square at noon. On the evening of the same day there will be a second reception at Devonport by the Worshipful the Mayor of Deveiiport, Mr. W. Waycott. The dinner and smoking concert will, as usual, take place on the Friday, at the Western Law Courts, the Guildhall. During the week of the Con- vention, an Exhibition of photographs and photographic apparatus will be held in the Art Gallery of the Plymouth Institute. The public will be admitted by ticket obtained at the door. The head- quarters will be the Royal Hotel and the Westminster Temperance Hotel. Coins as Weig'hts and SKeasures. — It has often been pointed out how the current coin of the realm may be utilised as weights. This has recently been done once more by Mr. Newton, late of the Royal Mint, who says that " a sovereign weighs a very- safe quarter of an ounce for foreign postage," while the crown piece is just on the right side of one ounce, and the half-crown, or its equivalent in smaller coins, will do quite well for the half-ounce. With reference to bronze coins, three pennies, five halfpence, or ten farthings respectively, make up an ounce. A halfpenny is also an accurate measure of one inch. It will often be handy to photo- graphers to know how English coins can be extemporised as metric weights or measures. A sovereign equals eight grammes, and a crown piece twenty -eight grammes as nearly as may be ; while a penny, for most practical purposes, may be used as a ten-gramme weight, it being but about three grains less. As measures, the diameter of a farthing is as exactly two centimetres as a halfpenny is an EngKsh inch, while a penny is the merest fraction over three centimetres Thus it will be seen that our coins may be, on an emergency, used (or both English and foreign weights and measures with approximate accuracy. _^.^__^_^__^^_ Trouble at the Chicagro Exhibition. — We briefly alluded a ■fortnight ago to the discontent amongst the foreign exhibitors at the Chicago show, with reference to the system of awards. Instead of subsiding, the dissatisfaction has extended and taken a decidedly practical form. The Commissioners of no less than seventeen foreign countries have withdrawn their exhibits from competition for awards. Their reason for this unusual step is the unsatisfactory replies to their communications on the subject, and that they consider that it is now too late for an International jury to be formed. Amongst the countries who have withdrawn beyond the European ones are mentioned Japan, Siam, and Brazil. The Commissioners' protest is regarded as of considerable importance by the authorities, one of whom, Mr. St. Clair, of Western Virginia, when the matter was under discussion, said that the matter was a serious one, that the Exhibition was threatened by it, and, if the matter were not settled quickly, it would result, he thought, in a lasting injury to the Fair, and bring disgrace to the country. We fancy he is not far wrong. Whoj out of America, evfer heard of awards being made upon a testimonial signed by a single expert ? Ima^ne photographs being so adjudicated upon at an International Exhibition ! However, English exhibitors, photographic and otherwise, may be content that their interests are carefully watched by the British Commissioners and their energetic Secretary, Sir II. Trueman Wood. By the way, the " big ahow " ia not up to the present proving, financially, the great luceesa our American cousins anticipated. A recent telegram stated that the daily admissions did not meet a third of the day's expenses. Since writing the above the Commissiont-rj of the foreign countries hav« decided to establish a board of jurors independent of those in the American aection, and to issue diplomas in disregard of the American awards. * GLASS POSITIVES ON GELATINE PLATES. At a recent Whitsun fete down in the country, one of the attractions was a booth or tent at which portraits were taken, the proceeds to be devoted to a local charitable purpose — the artist being of the sterner sex, while a bevy of fair damsels did the canvassing, flitting about amongst the crowd of country folk with specimens, and bringing the customers " up to the scratch." A brief examination of one of the samples showed that it was of the old glass positive type, but though a very fair picture, it was evidently not on collodion, being wanting in the extreme delicacy and brilliancy of the better class of that style of portrait. Feeling somewhat interested, I accepted the invitation of an acquaintance to accompany him inside "to be taken," not feeling equal to 'facing the ordeal myself. On entering, I found myself in a plain square tent, entirely devoid of ornamentation of any kind, and bare of furniture except for a single chair, and the camera mounted on a tripod stand. One corner was partitioned off, and from the square of coloured medium visible, evidently formed the dark room. The first thing of importance that attracted my attention was a small heap of paper that had been thrown out of the dark room, and apparently consisted of the wrapping of ordinary dry plates; and indeed it soon became evident from the short exposures given that gelatine films were the means employed. One portion of the roof of the tent was open to the sky, in approved country-fair fashion, and there were no unnecessary complications in the way of blinds, screens, or curtains to motlify the lighting of the sitter, all that being left to the chance of the " pitch" — which may, of course, have been intentionally chosen. At any rate, in all the examples I saw, the lighting was fairly good, and free from excessively heavy shadows or contrast. After my friend had been taken, he was requested to call back again in an hour's time, a slip of paper bearing a written number being handed to him for presentation when he claimed his picture. As the business done seemed to be fairly good, I was still more puzzled to account for how the plates were developed, washed, dried, blacked, and mounted in an hour's time ; so we returned punctually, and fortunately found the " studio " empty, a lull having occurred in the business. The portrait — a by no means bad one — was at once handed to its owner, and consisted simply of the glass plate, previously blacked or varnished, and backed up with a piece of dark-coloured paper, and the edges bound after the manner of a lantern slide, an entirely novel style of finish so far as I am aware. Explaining that I dabbled a little in picture-making by photo- graphy, I got into conversation with the artist, who turned out to be a local amateur — one of the hateful " shamateurs " again — though a* there was, I was told, no professional photographer within ten mUes at least, the poor fellow was perhaps doing nobody any great harm. He proved very agreeable, and in no way reticent as to his mode of working, having undertaken the task, as he explained, " for fun," and to add something to the organ or harmonium fund to which the pro- ceeds were to be applied. He employed, he said, no special plates, a fact I had already satisfied myself of by picking up a set of developin^f instructions from the heap on the floor, those he used for ordina*; work answering his purpose perfectly well. In reply to a question as to how he got the necessary positive ap- pearance so comparatively unusual with gelatine plates, he replied that the plates he used, when developed clear of fog or stains, always in his hands gave a fairly good positive after drying when viewed through the glass, but that he had been struck by the great improve- ment in this respect when using some of the newer developers, especially para-amidophenol, which was the one he used. So marked was this effect that he had been induced to try to still further im- 340 THE BRITISH JOURNAL OF PHOTOGRAPHY. [June 2, 1893 prove it for merely experimental purposes long before he ever dreamt of his present task, and this is simply how it was done. The exposure given was a "full'' one, rather over than under, ■what was absolutely necessary, under-exposure being fatal ; the de- velopment was commenced with a solution of normal strength, but containing a good dose of restraining bromide. With this the image was brought out until the picture was visible in all its details, but without allowing a vestige of veil to appear in half-tones or shadows. When the right point was reached the plate was at once dropped into a dish containing a thirty -grain solution of bromide, where it remained for a minute or so. If, on examination by transmitted light, the image did not appear quite strong enough, another applica- tion of the developer was made, which acted as an intensifier only, producing no more detail and no fog unless needlessly prolonged. The fixing was performed in the acid bath, which my informant con- sidered gave clearer shadows, the all-important point. " But how about finishing in so short a time ? " I asked. " You cannot have a very perfect system of washing here under present circumstances, and as for drying " " On the contrary," he remarked, with a smile, "I pride myself upon my system, although it may not be perfect, and with the assistance of an efficient staff — but step this way, sir." I accordingly followed into the partitioned-off portion of the tent, a part only of which was dark room. Here I found the staff consisted of a couple of youngsters of about twelve and ten years, to whom I was introduced as the " manager of the drying department '' and the " chief varnisher." " I am rather short- handed at present, so we have to do the best we can, and I expect my Btafi to make themselves generally useful : but in the early part of the day I had a ' manageress of the mounting department/ but she got tired of it." With this brief introduction my new acquaintance then proceeded to develop, wash, dry, and finish a plate, several of which, of " sitters" he was acquainted with, were put aside for future develop- ment. The development has been described, and, when fixed, the picture was left to soak for two or three minutes (or more if there happened to be anything else to do) in a dish of water. Repeated jugs full of water were then poured over it from a bucket, the same water being used over and over again ; the same operation was then repeated over a second bucket, the water in which he explained was " not quite so thick," and then, after pressing between blotting-paper, the plate was dropped into a dish of alcohol. I hazarded the sugges- tion that that surely was not sufficient washing, especially after many previous plates had been treated in the same water. " No," he re- plied, " it is not finished yet,"' and taking the plate out of the alcohol and holding it up to the light in the open air, he pointed out that the imremoved hyposulphites had been precipitated in the form of a fine opalescent deposit. Upon again placing the plate in water for a few minutes the alcoholic " greasiness " and the opalescence disappeared, and, after again blotting off the surplus water, a secondjsoak in alcohol followed, and it went into the " drying department." Here a small paraffin stove was provided, and also a simple fan rigged upon a wooden framework and worked by treadle. Holding the picture over the stove and vigorously working the fan at the same time, the elder of the two lads, sons of the chief operator, very soon lad the film dry, a careful watch being kept that no symptoms of the film dissolving appeared, in which case less heat and more draught ■were applied. Next it was varnished by the younger boy, and in the absence of the proper mounter it became any one's duty to finish it. The whole process, however, occupied little over half an hour from commencing development. I have brought this matter forward not merely to show that positives can be taken on ordinary gelatine plates, but also because in the modus operandi there are one or two points that may prove useful at a pinch, notably, the combined operations of rapid washing and drying. The use of nlcohol in the removal of hypo was proposed in Paris some years ago, but has never been generally employed, although it may often prove useful. In conclusion, I may add that I have since succeeded in turning out very respectable positives on several different brands of com- mercial plates, but as a rule I find the slower kinds give the best results. W. B. Bolton. CONTINENTAL NOTES AND NEWS. nXessrs. Ziuml^re's Coloured Photograpbs.— At a meeting of the Academie des Sciences last month, M. Lippmanni exhibited several coloured photographs by Messrs. A. & L. Lumiere^ by the interference method, on orthochromatic plates, prepared according to the formula given last week (p. 325). The subjects included the solar spectrum, a painted landscape, a bouquet of arti- ficial flowers, a Newton's disc in coloured glass, and several chromo- lithographs. It is stated that the whites of the subjects were- correctly rendered, but were only visible at the regular angle of reflection, otherwise they were seen as of a brown tone. Absence of Kalatlon ft-om Fhoto-IMCicrograpIis. — Apropos of M. Monpillard's paper on Orthochromatism applied t«Je<< May 18, 1893. June 2, 1893] THE BUITISH JOURNAL OF PHOTOGRAPHY. 349 W. No. 10,001.— "A New Multiple Revolving Photographic Dark Slide.' Wilson. -M<<«i 3/iiy 19, 18!'3. No. 10,0«to< .Vay 19, 1893. No. 10,131.— "An Improvement In Photographic Apparatu.i." W. J. Dm BlS.—JMteil May 20, 1893. ifleettnssS of SocictirjS. MEETINGS OF SOCIETIES FOR NEXT WEEK. Date of Useting. 'i^ue 5 Name ol Society. Dundee Amateur Peterborough (Annual) Putney Richmond South London Stereoscopic Club , Birmingham Photo. Society Brixton and Chipham 6 1 Exeter 6 Hackney 6 , Herefordshire 6 [ Lewes H North London ti Oxford Plioto. Society 6 1 Paisley 6 Rochester , 6 Rothcrham 6 Sheffield Photo. Society 6 , York Edinburgh Photo. Society .. Leytont^tone Photographic Club Sonthport 7 Southsea 7 Wallasey 8 Birkenhead Photo. Asso 8 1 Gloesop Dale 8 t HuU S London and ProTinoial 8 .„ Manchester Photo. Society ,. 8 North Kent 8 Oldham 9 Cardiff 9 Croydon Microscopical 9 Halifax Camera Club 9 Holborn 9 Ireland 9 Maidstone 9 WestLoudon 10 j Hull Place ol Meeting. Auo. Studio, Nethcrgrate, Dundee. Museum, Minster Precincts. High-street, Putney. Greyhound Hotel. Hanover Hall, Banorer-park, 8.K. Brooklands Uot«l, Brooklands. Club Room, Colonnade Hotel. 37*», Coldharbour-lane, Brixton. City Chamber.-^, Gaudy-st., Exeter. 206, Mare-street, Hackney. Mansion House, Hereford. Fitzroy Library, High-st., Lewes. Canoubury Tower, Islintrton. N. Society's Rooms, V.id, Higb-street. 9, Gauze-street, Paisley. Mathematical School, Rochester. 6, Frederick-street, Hotherham. Masonic Hall, Surrey-street. Victoria Hall, Goodrauitrate, York. 38, Castle-street, Kdinburgh. The Assembly Rooms, High-roa^l. Anderton's Hotel, Fleet-street, KO. The Studio, 15, Cambridge-arcade, 3, King's-road, Southsea. Egremont Institute, E{n"emont. Y.M.C.A., Grange-rd., Birkenhead. 71, Prospect-street, Hull. Champion Hotel, 15, Aldersgate-st. 36, George-street, Manchester. Gravesend. The Lyceum, Union-st., Oldham. Public HalljGeorge-street, Croydon Booms, 15, Dawson-street. Dublin. *' The Palace," Maidstone. Ohiswick School of Art. Chiswick. 71, Prospect-street, Htill. LONDON AND PROVINCIAL PHOTOGRAPHIC ASSOCIATION. -May 25, — Mr. P. Everitt in the chair. lareply to a question from the Chairman, Mr. J. Cadett said he was ex- perimenting with the amyl-acetate lamp for standard light purposes. " The Speed of Plates." Mr. R. Child B.ayley exhibited plates that had been exposed to light and xhibited different degrees of colouration, as bearing upon a remarli of Mr. H. A. Lawrance on the same subject before another Society. Differences in colour between the ]ilain bromide and bromo-iodide pKates were noticed, which Mr. Cow AX said wouhl depend on the composition of the films. No suggestion was made as to how this method could be availed of for telling the sen-sitive- nesa of plates. "Rbversal." Mr. J. E. Smith showed a negative made on a Paget plate two ye.ars old liicli had three seconds exposure with/-8, and was developed with pyro and iiimonia, development being rather forced. The plate showed complete versal. The Chair.max asked whether the rapidity of the plate might have increased y keeping, and, aprupoa coloured fog, also inquired whether ammonia-])re- : ired plates were more subject to it than boiled plates ? .Mr. W. E. De;benha.v observed that red fog might be removed by treating the plate with bichloride of mercury. " Flatness or Field— Spherical Aberration in Tele-photo Lenses." In reply to a question as to whether it was possible to produce a lens having a round field which could be flattened at will without decreasing the aperture, Mr. Debenham said a rectilinear lens might be made to have a round fiehl by bringing the lenses together, and flattened by separating them. Some discussion ontele-photo lenses toolc place, Mr. Debbnham remarking at it was an advantage to have an arrangement for adjusting the s]>herical ■erration so as to perfectly correct the combination for degrees of enlarge- •i-iit. Mr. T. Bolas approved of Mr. W. K. Barton's arrangement, which was tuated by a nulled head outside the mount. HALviTioN and Backing. Mr. J. S. Teape showed a plate that had been backed with caramel, vposures behind diamond-shaped openings of from twenty-live inches to sixty inches of magnesium at twelve inches distance being given. No halation was apparent. A quarter of an inch of magnesium would have sufliced for a normal exposure. He also showeil a Sandell plate that haits sliould never write on bofA sides 0/ tHe piiper. No notice is taJMn of conimunicationi uiUess tfie names ond addresses 0/ tfic «Tif«-s are gtoen. THE CONCENTKIC LENS. To ihe Editok. Sib,— I have carefully read Mr. StiUman's letter of May 17, much of which better supporta my contention than his; but the sentence, "On any given object I can focus as sharply with /-16 as with any smaller stop," ia just what I contend is incorrect and misleading. Mr. StiUman apparently proves to his own satisfaction my incompetence because I cannot do this, forgetting that it is open to me to retort, that it is some evidence of incompetence when a professed expert cannot obtain better definition with a high-class lens at /-64 than he can with the full aper- ture. There is no need to confuse the issue by dragging into the Con- troversy the power of printing processes to render the definition. I have a letter from Messrs. Boss before me, in which occsrs this sentence, " For really sharp definition we do not recommend the Con- centric being used with a larger aperture than /-22." Mr. StiUman gives himself away entirely when he admits^ that in making negatives for enlargements he uses the smallest stop. Kow, such negatives are generally of small size, not necessitating the stopping down of a ten-inch Concentric to obtain covering power, so what does he stop down for ? Definition, of course, wliich is not sharp enough for enlarge- ment at /'-Ifi. Ye gods ! Delicacy of touch and eyesight, following the sentence, " I alwavs ' mark,' aXviays focus at /-16," or full aperture, and this. Mr. Editor, after calling Mr. StiUman's attention to your very able article on the -'Focal Peculiarities of Wide-Angle Lenses," for the Con- centric is a wide-angle lens. Did any practical exponent of any art ever before refer to his less- experienced fellow workers as " duffers ? " If Mr. StiUman has any faith in his contention, it should be as safe to use the Concentric at/-16 as at /-22, even for the duffers, for they at least have eyesight. My protest was not made on behalf of experts — they can take care of themselves-— but for the guidance of earnest, if less experienced, workers who were in danger of being misled by Mr. StiUman. Will Mr. StUlman send his lens to the authorities at Kew for report on the single point, " Does this lens define as sharply on any given object at /-16 as it does at /CI ? " If he will do so I pay all expenses if the reply IB adverse to my contention. — I am, yours, Ac, F. H. BuHios. Houndhay, near Leeds, May 27, 1893. FOCUSSING THE CONCBNTEIC. To the Editor. "■ Sir, — I am not surprised that some users of the Concentric lens have found a difiiculty in getting absolute definition with it at /-16, and as most men consider their inability to do a thing as proof presumptive of its being undoable, it is not surprising that the unsuccessful experi- menters denounce the pretentions of those who assert that they have succeeded as mere swagger, or worse, for that is what the denial amounts to. And as I have asserted in the most unqualified terms that the lens is capable of doing perfectly defined work at/-16, 1 am ready to maintain it by the best of proofs, the work itself, done with the lens at that opening. But, at the same time, I will explain to the men who fail the probable reason of their failures. Any perfectly constructed lens wiU have a region inside which the definition is perfect, as lenses go, and with the opening for which they are calculated. I do not say that the defi- nition is as perfect as it would be in a microscopic lens ; it may or may not be. It is as perfect as the needs of photography require, or can profit by, or the eye distinguish on the ground glass. In the old form of lens, in which the field was a concave one, the centre of the field was the point at which the focus was most easUy determinable, but the moving forward of the screen brought other portions of it into focus, so that, witliin a certain range, some portion of the screen always showed definite detail, i.e., the maximum sharpness of which the lena was capable. A slight displacement of the screen did not therefore throw the picture out of the focus, and, as it was the custom to stop down for a flattening of the field, no harm was done by a little inexactitude. While, therefore, the operator found no injury from a slight margin in his focussing, or a trivial inaccuracy in the placing of the screen in the camera (and in one case I found that the screen of my camera was the one thirty-second of an inch out of place), so long as he had the old form of lens to deal with, in the new lens he had na range whatevM, the whole field lying flat as the screen itself, and, like Wordsworth's cloud, "moving altogether if it move at all," so that, it the ground glass is coarsely ground and does not furnish a surface sufliciently fine to render the delioaoy of detail of the image, or the position of the screen is a fraction of an inch ever so small out of the exact position of the focus of the lens, absolute accuracy in ocussing is a matter of luck, a ' ■■ "- trange in which it ia possible to find a satisfactory sharpness being diminished in proportion to the largeness of opening given to the lens, the larger that opening the more precise must be the adjustment of the screen. It will be seen that the accuracy required, both in the racking out of the screen and in the construction of the camera, so that all chance of error should be avoided, is absolutely mathematical, the one-hundredth part of an inch being enough to diminish perceptibly the definition on any given plane. Now, it rarely happens that the screen possesses a surface of the fine- ness of texture that is required for perfect focussing, and in my own case I have had to wax the centre of the ground glass ; and it very often happens that there is in the construction of the camera a trivial inexacti- tude in the adjustment of the screen which would pass unnoticed in the use of the lens with a hollow field, but ruins the definition with the Con- centric. In short, who uses the Concentric, works with a tool which must be employed with a mathematical exactitude, and those who do not find it mathematically exact must find the fault in their own operations. I have not always in my own work, found that I had hit the finest defini- tion, but when I have taken the requisite pains, I have always found that the result proved that the definition at/-16 was as perfect as I can get with a smaller aperture, so far as my eyesight wUl serve me. Of course, when the least error is made in either of the ways I have indicated, the use of the smaller aperture will increase the sharpness of definition, i.e., it diminishes the effect of the error. Eoss it Co. advise that the focus should be obtained with the aperture /'-22 and then, if it is desired to use the larger, that the lens should be opened out ; but begging pardon for the liberty I take in differing from the constructors of the lens, this seems to me illogical, for if the focus is obtained with f-'22 and the image at/-16 is sharp, it proves only that in the other case of focussing with /-KJ directly, the difficulty ia in the adjustment, not in the power of defining, for the lens cannot define the better for the manner of focussing — if the lens will define at/- 16 it will do it whatever opening has been used in the focussing, and if it does not, the fault is in the operator or in the camera. That the planigraphic lenses, as we may call those made with the new glass, giving a flat field, have a shorter focus than the old form of spheri- graphic lens, is certain, and the proof is in the using, as I have satisfied myself by careful comparison on the camera, and the new lens, while it gives its adjusted plane with equal sharpness, also gives the nearer or more remote planes with a closer approximation to perfect definition than the old one, but this is only an approximation, for mathematically, the lens can only give one plane perfectly, which it does with the aperture of /-16 and all assertions to the contrary are based on misapprehension or misapplication, but this faculty of giving greater depth of focus, increases the difficulty of accurately focussing, as it makes the error resulting from a alight displacement, so much the greater as the focus is shorter. The head of the great photographic establishment of the Italian Government, Signor Gargiolli, who employs the Concentric for nearly all his work, and the Zeiss form for the rest, confirms my statement that the former gives perfect definition at/-16, with the additional charm over that given with the small stops of the latter, that it gives a representation more like the actual appearance to the eye. Being obliged by the nattire of his work to exact the most precise definition, he is a better witness to the power of the Concentric than I am, for to most of my work, which is merely picturesque, it is of no importance whether it be of the most perfect definition or not. It is impossible that the difference between the results reported by other experimenters and mine should depend on the accident of a better construction of the lens ; for we know, in the first place, that there is no appreciable variation in the Eoss lenses, and because between the four Concentrics which I have personally used, and am using, and those of Signor Gargiolli there is no difference whatever. It is a matter of prudence for the makers of the lens to advise the use of a small stop for focussing, simply because it is easier to find the focus when so used ; but the recommendation to open out to the larger opening after focussing, implies that they are confident in the definition at the larger stop, which is the question at issue. I do not agree with the advice, nevertheless, for it seems to me that the adjustment of the focus must necessarily be more exact when done with the larger opening, as it is more difficult to hit the exactitude. I see no reason for deferring to vision, which is imperfect, to manipulation, which is careless, or to apparatus which is not exaetl.v fitted for the purpose. And the fact, which I admit, that I do not myself always hit the absolute definition of which the lens is capable, only proves that I am not always careful, while the occasional occurrence of a definition which is ideally perfect proves that it is not the fault of the lens that I do not always get it. — I am, yours, &c., W. J. Stillman. Rome, 27th May, 1893. MOUNTING GELATINO CHLOBIDE PEINTS. To the Editor. Sib, — I notice difficulties are met with in this operation. Let your correspondent get an old linen handerchief, free from fluff. Get some lady acquaintance to sew it roughly over a few pieces of thick blotting- paper, and you have a pad that will leave no fluff on prints and never stick. I have found it invaluable. — I am, yours, &c., Othello. May 29, 1893. June -2. ISOn] THE BRITISH JOURNAL Ot PHOTOGRAPHY. 251 MKTOL. To the Editor. Sir, — Since I wrote last week I discovered too late to add to my article that (or the very highest quality of result with metol you must use ammonia. This gives the most beautiful imaga I have ever seen from any devel^iper, though it docs not answer so well if the solution is to be used over and over again, owing to the volatile nature of the ammonia. I make a solution of one ounce strong ammonia and two drachms bromide in ten ounces of water, using the fluid drachm of this in each two ounces of developer. Say, one ounce stock solution of metol, as given last week, one drachm ammonia solution, and seven drachma water, varying the proportions pro re iiati'i. — I am, yours, *c.. May 2'J, 18'.!3. W. B. Bolton. PHOTOGK.VPHIC CONVENTION' OF THE UNITED KINGDOM. Pi.YsiouTH Meetis^, July 3 to 8, 1893. To the Editor. Sir, — In connexion with this year's Convention to be held at Plymouth from July 3 to July 8, an exhibition of photographs, photographic apparatus and appliances, will take place at the Art Gallery, attached to the Athenirum BuiWings. The charges for wall space will be 3(J. per square foot, with a minimum of 3.^•. ; and those for table or floor space, &d. per square foot, with a minimimi of o». Intending exhibitors will kindly apply for space, not later than June 24, to the Hon. Secretary, Mr. F. P. Cembrano, jun., 10, Cambridge-gardens, Richmond, Surrey ; or to the Hon. Local Secretary, Mr. R. Hansford Worth, C.E, 42, George-street, Plymouth, stating the nature of their exhibit and space required. All applications must be accompanied by a remittance^for the amount of wall or table space desired. Exhibits should be delivered, carriage paid, and addressed, " To the Hon. Secretary, the Photographic Convention, the Athenaum, Plymouth," not later than ten o'clock on the morning of Saturday, July 1. The Executive, while exercising all reasonable care and supervision, will in no way accept any responsibility for any loss or damage to exhibits either in transit or during exhibition. Exhibitors may have an attendant present to look after and explain their exhibits. — I am, yours, &c., F. P. CEMEK.tN0, jun., May 2lj, 1893. Hon. Secretary. SWITZERLAND. To the Editor. Sir, — If your correspondent " C. B." requires topographical informa- tion concerning Switzerland, he will find almost all that is needful in Buedeker'e Guide. With regard to plates passing through the Douane, I have dnly once had any trouble, viz., last July. Travelling by the P. L. and M., on reaching Tallorbes I was interrogated as to the contents of certain boxes, and, learning that they were sensitive plates, they charged me, a small fee. I remonstrated, telling them that I had never had to pay before, but to no purpose. On returning, the Douaniers took no notice of the same boxes re-entering France at Pontarlier. You are con-ect in saying that a passport is not needed in Switzerland, but I have frequently found more civility at the post.oflices, both in that country and in Italy, by showing my name on my passport than other- wise. A passport can be obtained by application at the Foreign Office in London, where a paper, to be signed by applicant and countersigned by a magistrate, will be supplied, and, for a small fee, the passport will be granted. It lasts a life-time, and is always useful in case of any trouble. —I am, yours, Ac, J. Carter Browne, D.D. Thurning Rectory, Oundle, May 29, 1893. PHOTOGRAPHY AS A BUSINESS PAST AND PRESENT. To the Editor. Sii'.,— ^n reply to your article on the above important question, 1 should hke to repeat what I have before suggested in a contemporary, that it is desirable that leading members of the profession should discuss this subject together and endeavour to formulate some course of action, with the object of endeavouring to dissuade the profession generally from pv.L-tites at once unprofitable and undignified — I allude more particularly to that of indiscriminate gratuitous sittings which has so increased in recent years, and has induced, I think, in the pnbUc mind a very erroneous idea of the value of the professional photographer's services, which is greatly aggravated by the mighty army of amateurs practising the art ior amusement with more or less succeas ; and is carried, I hold, beyond ^B legitimate bounds when extended to other than bond-fide public people and professional sittings (or the purpose of studies and pnblictk- lion. Then again the honour which is so continually thmtt npon us, with or without permission or payment, of having our work reproduced by a multitude of illustrated papers in various forms of process work, often the veriest smudges and barely recognizable, is a matter worthy of dis- cussion. These may not in themselves answer your question, but I think they are entitled to consideration, if only members can be brought together to discuss them, when others of greater importance would no doubt arise. — I am, yours, Ac, William Grove. 63a, Baker-street, Portman-square, ^V. i5K|)angf GTolumn. %• yo charge is made jor inserting Exchanges of Apparattts in this column; but none will be inserted unless the article wanted is definitely stated. Those whospecify their requirements as "anything useful" will there/ore understand the reason of their non-appearance. The full name of the advertiser must in all cases be given for publication, otherwise the Exchanges will not be inserted, Will exchange 158 nambers of Pdofography, from No. 15 op, for interior bac'fgionnil or cheap hand camera. — Address, Moore, Backfastleigh. Will exchange Merritt tvpe-writer for half-plate camera.— Address, F. HotwitL, Quay Houae, Bideford. Wanted, an eiohange of backgrounds (interior), 8x7, will send phot graph with pleasure.— Address, A. E. btaslev, Lansdowu stndK), Strond. Will exchange Duchess half -plate camera and three double slides in good condition for good quarter-plato hand camera.— Address, William HEMiNki, Kast Clitl Scadio, Whitbi-, Yorks. Exchange 11x11 square cauiera, three doable dark slides by Dallmeyer for ten ar fom-teeu.inch *' Fernande " or " Globe " enanieller, differences adjnscsd. — Address, M. E. Mallett, 258, Brixton-hill, S.W. I will exchan'je a quarter-plate camera, with rectilinear lens, and s'.x double slides and tripod stand tor halt-plate camera and lens by a good maker. Difference ad- justed in cash. — Address, Y. SiMCO, Ohemist, Wellmgborough. ansttoetis to CorresponDcnts. •,* All vmtters intended for the text portion of this JotlRNAL. including queries and Exchanges, must be addressed to " The Editor, The British JOURNAL OF FhotograI'HY," 2, york-street, Covent Garden, London. In- attention to this ensures delay. ,* Correspondents are informed that we cantwt uruiertake to answer com- munications through tlie post. %* Communications relating to Advertisements and general business affair* should be addressed to Messrs, Henby Gbeknwoob i Co., 2 York-ttreet, Covent Garden, London. %* It would be convenient if friends desiring advice respecting apparatus, faiiures in practice, or other information, would call at the Editorial Office either on Wednesdays from 4 to 6, or Thursdays from 9 to 12 noon, when some one of the EdiUjrial staff will be present. Clifford E. F. Nash. — Ground rice is meant. Bristol Boy. — Nothing ever eventually came of phosphorescent emulsion proposed twelve years since. W. Cope. — Consult an analytical chemist in your town, who will undertake a proper examination of the mounts for a fee. J. Peach. — In the absence of details of the method referred to, we cannot, of course, say anything as to its practical value. S. Thoene. — On the whole, No. 1 is to be preferred on account of the non- repetition of pose in the fishermen. Both are good pictures however. A. Clarke. — Possibly the mottled appearances will not be apparent if tte developing solution he slightly warmed. See articles on the subject in last volume. Ed. Clarke. — Try ordinary negative vami.sh mixed up with lampblack. Othello. — If French chalk fails to prevent sticking, try beeswax dissolved in benzole. MOSTAGUE Babstow. — You are probably thinking of the Optiraus drawing attachment to a lantern. See p. 753 of The British Journal Photographic Almanac for 1892, A. SMitu. — The only way to recover silver from gelatine paper prints is from the fixing bath. For opalines, try the effect of giving a coating of dilute albumen to the glass. This will prevent the peeling ofl. F. Wills. — Granted that, according to your figures, the silver, the bromide^ and the gelatine cost so very much less than the price at which the plates are .sold, you have quite overlooked the glass. Does this cost nothing f Printer. — The spottiness of the prints may possibly be due to the hvpos»lphite- of soda. Be that as it may, hyposulphite tliat is damp and discoloured, and has an offensive smell, is quite unfit for photographic purposes, and shoold not be used. THE BRITISH JOORNAL OF PHOTOGRAPHY. . [June 2, 1893 Mason.— The appearance of the negative is caused by its being imperfectly washed before it was varnished. It i.s quite a mistake to suppose that any varnish is a perfect protection if the film contains hyposulphite of soda, and damp silver jiaper is placed upon it in the the printing frame. W. Sellman. — The print h.as stood well so far, but it has been exposed only six months. If you call upon us, we can show you silver prints that have been exposed, without showing signs of fading, for eighteen years. We also possess the first platinum prints that were made, and can attest the un- diminished brilliance of the same. Collodion. — A sixty-grain bath, that has been used for sensitising paper, is not suitable for the collodion process. In the first place it is far too strong for the purpose. In the next it is charged with organic matter which would be fatal. It might be possible to remove this, but it would not be worth the trouble when a new bath is so easily made. Delta. — If bulk in the apparatus is of no consequence it would be well to have a finder and a focusser in one. But if you can focus independently of the finder, it is only requisite that the image received by the working lens is correlative witli that of the finder, so that when you look on the finder ground glass you know just what to expect in the negative. R E. E. says that, on sensitising some rough drawing paper, according to a formula given in the JounSAL a few years l)ack, it became covered with a number of fine spots, which began to show before the paper became dry. He asks how they are to be avoided ! — The fault is, no doubt, in the paper, and, if so, can only be avoided by using anotlier brand. A. Walleh. — So far as can be .judged from the appearance of the print, we are led to infer that the lens was not sufiiciently shielded from light during the exposure of the plate. From the direction of the cast shadows the sun must have been shining very much in the direction of the lens at the time. There is_ no remedy but to retake the negative. Probably more brilliant prints might be obtained from it on bromide paper than is possible on albumen. N Hos. Sec. — If certain prizes are offered for "the best" photographs in any _ particular class, and those competing in that class are considered by the judges to be below their preconceived idea of excellence, they cannot, how- ever, withhold bestowing a medal for the best of such inferior photographs ■unless there has been attached to the published conditions a statement that they are empowered to withhold medals at their discretion. They could, we believe, be brought to their senses by a court of law. T. A, E. — 1. The front lens of an ordinary portrait combination, worked with an aperture of/-8, will do quite well for taking a group of several persons, but with such an aperture crisp definition must not be expected. 2. With that aperture it will be as quick acting as a rapid combination with similar ■opening. Indeed, theoretically, it will be quicker. 3. The convex side of the single lens should be next the ground glass. 4. The chemical and wisual foci will be coincident, so that no after-adjustment will be requii'ed. Manchester Photographic Society.— June S, Liverpool (hand camera). Mb. Norris B. Steadman, formerly of 30a, Bold-street, has now removed •to 129, Dale-street, Liverpool. Leyton-stoxe Camera Clur— June 3, the Tower of London. Leader, Mr. •G. H. Cricks. The Qub will assemble at the gates at three o'clock. Oldham Photographic Society.— June 3, Saturday, Chew Valley. Depart, "Clegg station, ten minutes past two p.m., for Greenfield. Ketura fare, Sd. Leader, Mr. J. Greaves, jun. ' Received.— The price list of Mr. C. H. Bradbrook, photographic printer and enlarger, of Chapel-street, Colchester ; T. Aston & Sou (Toning Powder) ; i5. hidey (BriUiantine). These and others in our next. -.v*^^; ^'','?"'2^'' ^^"" ^^^ compUed A Few Notes for intending visitors to the World s Fair at Chicago, in which a great deal of information likely to be useful to photographers and others is condensed. Drij Plates for May contains an article by Mr. J. Cadett on " Speed Deter- ■mmation, wliich gives in a clear and popular form an explanation of Messrs mrter & Driffield s system of measuring the speed of plates. We gatlier that Ih-y Plates is to reproduce Messrs. Hurter & Driflield's papers on the subject. "Optimus" 100- Guinea Competition, 1893. -Messrs. Perken, Son, dt Kayraent, of 99, Hatton-garden, announce a series of competitions the pictures •to be taken with Optimus lenses. There are nine classes, open to both pro- i^fir ni y. *%*,"*"'"cJlo''°*X'''5''"r''-'- The competitions will not be closed unti December 31, 1893 The prizes are to take the form of apparatus of Xreat value iuU jiarticulars and conditions of the competition can Ve obtained of Messrs. Perken, Son, & Rayment, 99, Hatton-garden. Exhibition at Hamburg. -An International Photographic Exhibition will be held m the Gallery of Arts at Hamburg from October 1 to 31, 1893 The following foreign representatives have placed their services at the disposal of «e Exhibition Committee for the j.urpose of inducing particii>ation in the torthcoming Exhibition by their respective countrymen and bv amateur photo! eraphic societies existing m the countries represented by them :-Belgium : V, /il'luard Ludwig Behrens, Consul-General. Brazil : Herr Wilhelm P^imp vT X ■ ^'"^' =,"??■ ^^- '°^- «''li*»rtz. Consul. Corea : Herr H. C *i„J^. T'';*^??*"'; D^nniark: HerrHenrik Pontoppidan, Consul-General. france: M. le Comte Leopold Balny d'Avricourt, Consul-General. Great Britain t The Hon. Charles S. Dundas, Consul-General, and Mr. G. Ambrose Pogaon, Vice-Consul. Greece : Herr Aug. William Gorrissen, Consul-General. Japan : Herr Martin Valentin Burchard, Consul. Mexico : Herr 0. M. Velez. Consul. Netherlands : Herr Richard von Schmidt-Pauli, Consul-General. Norway and Sweden : Herr Benit Anker Biidtker, Consul-General. Persia : Herr Carl von Haase, Consul-General. Portugal : Le Commandeur Francisco van Zeller, Consul-General. Sandwich Islands : Herr Ed. F. Weber, Consul. Spain : Herr Tomas Ortuilo, Consul-General. Switzerland : Herr Paul Edward Niilting, Consul. Turkey : Herr Rudolf Hardy, Consul-General. United States : Hon. W. R. Estes, Consul, and Mr. Charles H. Burke, Vice- Consul. Zanzibar : Herr Albrecht Percy 0'Sw,ald, Consul-General. Applica- tions for programmes, forms of entry, and inquiries should be addressed to the above-named Consuls, or to Das Ausstellungs-Comitte des Amateur-Photo- graphen-Verein, Hamburg, Schwanenwik 33. Prokessor W. K. Burton on " Density Ratios." — Photographic Scraps for June contains a letter from Professor W. K. Burton, in which he refers to some experiments that have resulted in proving conclusively that the per- missible Latitude in exposure is even greater than lie had supposed. He says : ** It is possible to vary the exposure as one to forty, and yet to get negatives giving prints that are identical, or that are, at any rate, so nearly similar, that an experienced jihotographer cannot tell which is from the negative that has had the longest exposure. By this I mean that, if one second is the shortest ex- posure that will give a really good negative with a certain kind of plate, I can give a second plate of the same kind an exposure of forty seconds, and get a negative that has no appearance of being over-exposed, and that will give an excellent print. The negatives can generally be distinguished by the dilterence in colour of the image. In some cases I have succeeded with exposures varying as one to eighty. This is, moreover, using the same developer, namely, pyro, with carbonate of soda — my favourite developer now for some years — merely varying the proportions of the ingredients, and without recourse to intensification. By using entirely different developers, it would be possible to compensate for greater differences. Moreover, the subjects selected were ordinary landscapes. By selecting a special subject, mostly very deep shadow, with only a small proi)Ortion of high light, it would be possible again to compensate for greater differences in exposure. I send you herewith prints from two negatives, one of which received an exposure of three seconds (with an extremely small stop), whilst the other, exjiosed immediately afterwards, on a plate from the same box, using the same stop, received an exposure of one hundred and twenty seconds. The plates used were, I may mention, such as are sold as ' ordinary,' but are of very fair rapidity, even as plates of the present day go. There is no great secret in the method used. The first plate was developed with the least quantity of pyro that would give sufficient density, one grain to the ounce of developer, and a mere trace of bromide, one-fifth of a grain to the ounce, used to restrain a slight tendency to incipient fog. In the case of the second plate, the pyro was increased to eight grains to the ounce, and ten grains of bromide of pot.assium were added to each ounce of the developer. The development was complete in the case of the first plate in about five minutes. In the case of the second it took twenty minutes. How, it will be asked, is this statement compatible with the dogma that the density ratios cannot be altered by development ? Even after allowing for the difference between 'density' -and 'opacity' as used by Messrs. Hurter & Driffield, it is not compatible at all, and it is, as a viatier of fact^ possible to vary the density ratios enormoush/ in negatireshydecelopiiunt. To demonstrate this, it is only necessary to expose two plates on a landscape, giving normal exposure. One is developed so as to give what would be understood as a ' good ' negative. That is to say that, amongst other things, it shows all, or nearly all, the shadow detail that is visible to the eye, and that the high lights are represented by a certain density. Now, it is quite easy to develop the second plate so that very little more than the iii"h lights are visible at all, yet these high lights are much more dense than in the case of the first nega- tive. It is evident here that neither the ' densities ' nor the ' opacities ' can bear the same ratio to each other in these two negatives. In fact, if two ' density curves ', were drawn, they Would cross each other." Illustrating the letter are reproductions from two prints of negatives that had received three and one hundred and twenty seconds exposure respectively. The difference in the nature of the results is difficult to detect. With this week's Journal vie present, as a supplement, a pholotypic remriduction by the well-known firm of T/ievoz cfc Co., of Geneva, of a study by Mr. William Brooks, of Reigate, the subject being a " Tower Wanhr," or, as he is more popularly termed, a Beefeater. The excellent qualities of Mr. Brooks's negative receive full justice frmn the process of Messrs. Thevoz, the effects of which are heightened by the grained surface of the paper upon which the impressions have been taken. We understand that photographs of the picturesquely garbed and historically interesting body to whom i/ie custody of the Tower of London is committed are not very common, and our picture should therefore have additional value. OONTBNTS, Paoi WHOLE - PLATE BINOCULAR PIC- TURES, AND HOW TO BEE THEM.. 337 OUTKOOR groups 33S GLASS POSITIVES ON GELATINE PL.VTES. By W. B. BOLTON KM CONTINENTAL NOTES AND NEWS .... 340 NOTi:S OX SOME PECULIARITIES IN THE ACTION OV" HYllROyUINONE lyriNOL] AND PYROGALLIO ACID DEVELOPERS, AND .tLSO OF WATER. ON GEI.ATINE DRY PLATES. Bv T, C. POTTER ', .111 PHOTO-ASTRONOMY AT THE CAPE OBSEBVAlVlBY IN 1892.-11. By C. RAY WOODS 341 ] P.lSJ BACKING AND BLURRING. By EI' WARD DUNMORE I" COMPOSITE HELIOCHROMY. By F. K. IVES ISOCHROMATIC PHOTOGIIAPHY i W.ITSON'S CAMER.1S FOR THE SEASON : OUR EDITORIAL TABLE . RECENT PATENTS • meetings of societies correspondence EXCHANGE column _WEBS 10 COERESPONDENIB I f THE BEITISH JOURNAL OF PHOTOGRAPHY. No. 1727. Vol. XL.— JUNE 9, 1893. VIEWING LANTERN SLIDES BY DAYLIGHT. At a time when, as regards the prolongation of daylight, we are in the month which occupies the position of being the middle one of summer, the exhibition of slides by the lantern is somewhat impracticable unless such be extended far into the night, or, as an alternative, the exhibition take place in a place capable of being especially darkened. What, then, is to be done by way of gratifying oneself or one's friends desirous of inspecting the outcome of camera trips to choice scenery, ancient cities, picturesque villages, or fashionable watering- places 1 The obvious answer is, Arrange to show them by daylight We are, of course, writing in the interest of the innumerable army of hand-camera snap-shottists, or of those wiser ones who, with whatever kind of camera they may have •elected, take special care not to omit taking with them a stand as well as the camera, or those whose " be-all and end- all " is the production of transparencies for the delectation of family and friends. No photographer is fully equipped who, in addition to his camera, is not also the possessor of a lantern for evenings and a table-stand for the parlour or drawing-room table for use •during the daytime, " ere the evening lamps are lighted ;" and, having just risen from taking part in a daylight enter- tainment, in which the last-mentioned of these has played a prominent part, we can the more strongly advocate its universal adoption. The optical requirements for constructing a table-stand for the purpose in question are simple. It is only necessary to interpose a large magnifying-glass, of short focus compared with its diameter, between the eyes and the picture. We are, •of course, assuming botli eyes to be used. But large louses are both costly and clumsy, and the same end may bo equally well attained by employing two portions from the margins of such a lens mounted one opposite each eye, taking care that the thickest portions are nearest each other. This serves the twofold purpose of magnifying the picture and sending the ray transmitted through it, so as to enter each eye under circumstances nearly approaching to parallelism, without which even the healthiest eye would be pained by the strain necessary to see, with both of them, any- thing brought so close to the eye. The prisms with which even the very commonest stereo- scopes are now fitted answer in an excellent manner for viewing with both eyes a lantern transparency ; but they must be mounted in the reverse position to what they are in the stereoscope, that is, instead of having their thin ends next to each other, these ends must be to the outside. Prisms of this nature, however, are open to the objection of being unable to give a great degree of magnification on account of the chromatic aberration necessarily present, eight inches being the focus beyond which it is unwise to go. Here is a curious thing which we noticed in examining a coloured slide. Having painted it so as to give a moonlight effect, a house in the near background and a number of sub- tropical trees by which it was surrounded were painted of a tint between a pale blue and French grey, to keep up the idea of the front not being illuminated by a bright moon almost overhead, although sUghtly behind. The windows were scraped out and painted a warm yellow colour. On examining this through Adams' binocular pautascope, which is without doubt the best of this class of instrument on the market — at any rate, the best we have seen — these yellow windows were seen as if projecting some feet in front of the wall of the house. This is just what any one acquainted with the laws of chromatics would have expected. Had the windows been blue and the walls red, then would the contrary effect have been produced ; the latter would now project, while the windows would retire. It is the application of the same law of chromatics that enables one — as we have long since pointed out and explained the reason — to see the large red flower, with its entourage of green leaves standing out in such stereoscopic-like relief when viewed by the large lens of the graphoscope. This is not the case when the large lens, usually biconvex and invariably uncor rected, is supplanted by an achromatic one, although, as a set- off against this, the latter is preferable for plain, uncoloured photographs. When a pair of round achromatic lenses are employed in an instrument such as the binocular pautascope of Mr. Adams, it is advisable that they be of short focus — say, from five to six inches — while it is necessary that they be mounted so close together as to permit the eyes to be opposite a portion of the lens situated between the centre and the margin. As it is well that the diameter of these eyepieces should be large, it may be, as we have found it the case, impossible to set them sufficiently close together to enable the eyes to be at a distance outside the centre of the lens to see the picture with the requisite displacement for distinct binocular vision, and without that straining of which we have spoken. In this case, nothing remains but to grind away a small portion of the edge of one or both, in order that their centres may be brought neai'er together, for, as just stated, it is the space outside of the centres — that is, between the centre and the outer margin — that forms the real eyepiece through which the picture must be viewed. I In order to conduce to comfort, it would be well that the I instrument were, when in use, inclined downward at a slope 354 THE BRITISH JOOBNAL OF PHOTOGRAPHY. [June 9, 1893 like the microscope instead of having to be directed against the sky. This position can be readily secured by hanging a mirror to the outside lower part of the ground-glass frame backing the slide under examination, and then inclining it so as to reflect the light from the sky. A white sheet of cardboard, laid flat upon the table, answers the like purpose. SOME CAUSES OF DEPRESSION IN PROFESSIONAL PHOTOGRAPHY. No one, we surmise, will question the opinion expressed last ■week by Mr. W. Grove — whose long experience in professional portraiture fully qualifies him to deal with the subject — that the prevailing system of giving indiscriminate free sittings has tended to cause in the public mind an erroneous idea of the value of the professional portraitist's services. From the way these sittings are now given, by some, on almost any pretence whatever, they must certainly greatly diminish what may be classed, if we may apply the term, the legitimate business of the portrait photographer. When this system was first introduced — and that was in the early days of collodion — it was confined for a time, if we remember rightly, to scientific men and men of letters. After- wards it extended to the clergy, the stage, and other persons of eminence, and, subsequently, to the ballet, rceterea nihil. With regard to the reduction of over-printed proofs on gelatine paper, Mr. Lindsay has, in a recent number, some interesting remarks. So far as albumen prints are concerned, there is no doubt the Ijest and only suitable reducer is a five per cent, solution of cyanide of potas- tasium. As to gelatine. I am less able to speak positively ; I must try Mr. Lindsay "s plan. But I shall not find it neces.siry to go to the trouble of dissolving common salt in hot water, and waiting for it to cool, for the simple reason that hot water will not dissolve chloride of sodium any more quickly, or in any larger quantity, than cold water. -Vccording to some authorities there is a slight difference, but it is fractional only. Poor " Cypher!" who writes to know what he must do, for the rain has got to his negatives and stuck them to the paper — the Editor very properly tells him there is no remedy but to retake the views. I would add to that advice, say, when you get your views again, do not print from them till they are varnished. You will then be free from stains on your negatives from your pai)er at any time, and, if the rain does agsrin attack them, you may, by dissolving off the varnish in spirit, have them as good as ever they were, unless the rain beats for a considerable time in this unwelcame proximity. Fees Lance. ANGLE OF VIEW. [London and Provincial Photographic Association.] . ., If we examine the picture formed by a photographic lens upon a screen of sufficient size, we shall find it is circular. This circle is the base of a cone of rays transmitted by the lens. Divide this cone in the direction of its axis. The section is triangular, and the angle at the apex is called the angle of view. Let us suppose the focussing screen is sjuare, and that the circle of illumination touches each side. A plate under such conditions would be unexposed at the corners. Y'et, to calculate the angle enclosed by such a plate, we have been directed by the rules hitherto accepted to take the diameter of this circle as a factor. It is an astonishing fact that these rules have the sanction of a number of writers, amongst whom may be mentioned Shadbolt, Grubb, J. H. Dallmeyer, Traill Taylor. Woodman, Emerson, and still more recently A. Haddon, the respected curator of this Society. To cover a plate such as has been described, it is evident the circliJ of illumination must enclose the plate, and not the plate the circle of illumination. We must therefore measure the diameter of the circle by the diagonal instead of the side of the plate. The perpetuation of the mistake is probably due to the habit, common amongst writers, to take data at second-hand rather than think them out for themselves. There are, however, two noteworthy exceptions. Dr. Eder, in his AicsfiihrlicAes Handbuch der Pkotoyraphie, gives rules and tables for calculating the angle of view included by a lens, and for that included on a plate. For the latter he takes the diagonal as the basis. Pro- fessor W. K. Burton also estimates the angle of view by the diagonal of the plate, according to an article on the Concentric lens in Photographic Work, February 24, 1893. Recently I criticised, before this Society, the rules laid down by Mr. Haddon for calculating the angle of view included on a plate. They were published in The British JoLfRXAL Photographic Almanac for the current year, and may be taken as correctly repre- senting the rules of the writers first mentioned. These rules take the longer side of the picture as the base of the triangle enclosing the angle of view. You may follow the rules and work the problem correctly, but the answer will always be at variance with the facts. Either the angle will be too wide or the focus of the lens too short, when you take the photograph. We mav also have a series of plates such as 15 x 0, 15 x 10, 15 x 11, 15 x 12, yet, by these rules, all will include the same angle, with the same lens, under similar conditions ; or, if we wish to include a given angle from the same station-point, we must use a lens in each case of identically the sami' focus. Further, no matter what position the lens may occupy on the front of the camera, the angle will remain the same. Rules giving such results are evidently wrong, and, as a more rational system, 1 wo lid suggest the adoption of the method used in perspective. The circle of illumination of a lens corresponas with the base cf 368 THE BRITISH JOURNAL OF PHOTOGRAPHY. [June 9, 1893 the cone of visual rays. The lens is the eye and the picture plane is the photographic plate. These are corresponding terms in photo- graphy and perspective. The picture plane is vertical, and must not extend beyond the base of the cone of rays. The angle of view in perspective is limited to sixty degrees to avoid that exaggerated appearance with which we are familiar in pictures taken with wide-angle lenses. But, for the purpose before us, this may be disregarded, since what is true of an angle of sixty degrees is also true of any other angle. In perspective, if the picture _ plane touches the edge of the base of the cone of rays at any point, it is said to include an angle of sixty degrees, and, similarly, we may speak of pictures including any other given angle. On the picture plane there are two important lines, the base line and the horizontal line; the base line is that upon which the picture rests, and the horizontal line extends from right to left at the height of the eye. Upon this line is the centre of vision, or centre of the circle forming the base of the cone of rays. The axis of this cone is called the principal visual ray, and corresponds with the focus of the lens. The artist may select any portion of the base of the cone of rays for his picture, and the photographer does a similar thing when he moves the cross fronts of the camera in arranging the subject on the focussing screen. What, then, are the conditions which determine the angle of view for any given picture ? First, the distance of the spectator from the picture plane, which, in photography, we may call tie focus of the lens. Second, the position of the centre of vision, which, as I have shown, will vary according to the position of the lens on the front of the camera. To ascertain the position of the centre of vision, we must draw a line perpendicular to the plate from the apex of the cone of rays. Where the line touches the plate is the centre of vision, and we must measure the distance thence to the farthest corner of the plate. We can now measure the angle of view by means of the table of natural tangents given by Mr. Haddon, the rule for which should be stated thus : — To find the angle, divide the distance from the centre of vision to the farthest corner of plate by the focus of the lens. Find the reareSf number to this in the table of tangents, and twice the arc opposite it is the angle required ; or, if we know the angle of view, and wish to find the focus, find the tangent opposite the arc, which is half the an^le of view. Divide the distance from the centre of vision to the farthest corner of plate by the tangent. The answer is the focus of the lens required. Mr. Haddon was unfortunate in the selection of the title of his article, " Angle of View included on a given Plate by a given Lens." If the lens is not opposite the centre of the plate, the whole angle of view is not included. But the expression is permissible if we under- stand by it the angle under which the picture is taken. I mention this merely to draw attention to the fact which some may overlook, that the angle is different if the lens is moved by using either of the cross fronts. It must also be remembered that a lens can be used to cover a larger angle if the axial ray is not perpendicular to the plate, as pointed out by Mr. W. E. Debenham when this subject was last under discussion. But, as I have used the term angle of view in relation to the picture, and not to the lens, the rules I have given apply to the picture only. If it is required to calculate the angle covered by a lens under the abnormal conditions mentioned, the necessary modification must be made in the formula. P. Evekitt, NOTES ON STUDIO-BUILDING.* This being the time of year when studio building is usually under- taken, and the matter having recently been discussed in the columns of this Journal, it occurred to me that, having worked in several different studios, and built two which answered their purpose fairly well, but which were capable of improvement, a few notes on their good and bad points might be useful as showing what to avoid, if not what to adopt. The chief matters to be taken account of are : Size, as regards length and width ; height and pitch of roof ; aspect, north, north-west, north-east ; amount of space glazed : kind of glass; near- ness or otherwise of neighbouring buildings, or possibility of their subsequent erection; supports for glass; roof on shadow side; blinds and method of firing ; tie rods ; ventilation. The first studio I worked in had clear glass in roof, and I fancy north-east aspect. We used to get the sun in, and I remember once placing a thermometer on top of camera and finding it registered 120° I'ahr. The next had either Hartley's rolled or else plam glass in roof, with plain glass at side. Aspect, north by northwest. In the middle of summer the sun used to shine in during afternoon, • Mr. Cole's article has been in type for a considerable time, but had to be held over through pressure of other matter. restricting us to the use of one end of the room for the time being. The framework of roof was of T iron, and inside walls painted paie blue. Light was quick, and lighting good. Dimensions about 27 x 12 or thirteen feet, with room to back out at one end when taking large groups. The side light came down rather low, about two feet or two feet six inches from floor, with short curtains along the bottom portion. Ridge roof, light only from one side. Another studio, dimensions about 30 x 1.5, also with ridge roof, had a narrow top light, with long sloping side ; glass all " white cathedral," or similar sort. This is a good kind to use where the studio is overlooked, as it prevents sitters seeing outside objects clearly, and gives a feehng of seclusion and privacy — more apparent than real,however, as from a little distance off any one outside can dis- tinguish objects inside, though not sufiiciently to recognise individuals. To entirely prevent outsiders seeing what is taking place inside, ground glass is necessary. This studio ran out end ways from the house on ground floor, and at opposite end were some fairly highly trees, so that, whichever end the sitter was placed at, the front top light was seriously cut oS. Walls and roof on shadow side painted chocolate, lighting being slow, except when very bright clouds were about, and always hard. There were no cross ties, and I was able to use a head screen for bust portraits. The next studio was in London, glazed at top on both sides of ridge with Hartley's rolled glass. One side of roof generally kept covered by opaque blinds. No side light, but a window at one end, which could be uncovered if desired. With the exception of this window, there was no glass lower than about eight feet, and wall of next house ran up higher than studio. Lighting too much from top, and consequently hard ; and, unless both sides of roof were un- covered (which gave flatness), light was very slow. The nextstudio was atthe seaside. Aspect something like north-west, sloping fight, starting at about three feet nine inches from floor, and running right away above wall on shadow side, a small portion near the wall being ceiled. On the south side were other rooms, with their roof running up above to meet the studio roof. There was thus a con- siderable air space up under the ridge. The studio was cool, except in middle of summer, when the sun used to peep in. Glass was plain, and to keep out sun tissue paper was pasted over it, which, owing to the sitters having to be placed close to the window on account of narrowness of room, gave considerable glare, and caused very large high lights in the eyes. I found four large opaque blinds in use, running on wires horizontally, each one covering one quarter of the glass. As the room was only about 20 x 10 ft. on the floor, and narrower still five or six feet above, the sort of lighting it was possible to get with sun shining in may be readUy imagined. Several smaller black muslin blinds were substituted for the four large thick blue ones (also running horizontally), which subdued the glare and enabled me to modify the lighting according to requirements. In winter time the tissue paper cut off too much light, so it was dispensed with, and when summer came round again mineral paper was used instead, with good results. The supports for the sloping light were of wood, and occasionally the wet found its way through. Ventilation was effected by lifting up hinged portions of the framework, with the dis- advantage that in wet weather the rain drove in. With reference to dimensions, 30 x 1.5 feet is a useful size, and, if there is a room opening out of studio in which accessories not in e very-day use can. be kept, the width will be enough for most purposes ; eighteen feet would, however, be better. The tendency nowadays is towards large work, necessitating large cameras and stands, which require to be kept handy and yet out of the way when not in actual use. I should have made my present studio eighteen feet, but was limited by width of ground. Thirty feet is long enough for most work ; but, if background carriers with projecting feet are employed, and some at each end of room, thirty-five feet would be more con- venient. Height. Up to eaves mine is eight feet, but nine feet would have been better, and, if studio is to be eighteen feet wide, height to eaves should certainly not be less than nine feet, assuming a ridge roof to be chosen. Height of ridge from floor is about fourteen feet, but rather more would have been an improvement, with the eaves at eight feet, and, with the eaves at nine feet and the width at eighteen feet, the height to ridge should be as much as eighteen feet. The steeper the roof the more easily will the snow slip off, and the cooler will the place be in summer. SuppoBT FOB Glass. I can speak strongly in favour of T iron. I have had it in use for seven years, and have never had any wet come in. Glass was painted over at edges before puttying in, and I believe the rabbet of iron also. The first two summers were very hot ones, and after the second June 9, 1893] THE BUITISH JOURNAL OF PHOTOGRAPH y. 3«0 it was fo\ind that a little of the paint and putty was the worse for wear. It was repftinted and puttied where necessary, and went for five summers without anytliing beinjf done to it, then had another puttying and painting, Ixiing apparently as good as when first put up. The framework for side light is of wood, witli a wooden plate. If building again, I sliould liave this also of iron, with an iron plate, which would obstruct less light at the eaves, and be less inclined to twist or warp. For another studio I built, which there was a possi- bility of wanting to remove, wooden rafters were used with patent zinc tubing to avoid fixing glass in with putty. The zincs were supposed not to require any other rafters, and were supplied extra strong for the purpose, but they were of no use as supports. liy fixing them on wooden rafters they answered all right, except for tlie bottom panes next to gutter, which were always slipping and break- ing till I had some iron .stops made and screwed on to plate. T iron has this disadvantage over wood, that, when it is required to attach anything in the way of supports for blinds and curtains, there is nothing to fix them on to ; therefore, at intervals along the frame- work, before the glass is put in, the iron should be drilled, and a few small pieces of iron screwed on inside, to which wooden rails can be fixed. On these rails any fittings can be easily attached. If an iron plate instead of a wooden one at the eaves is adopted, this should also be drilled, and a strip of wood bolted to it for faxing side blinds or cords to. It must be remembered that in frosty weather the roof gets very cold during tlie night, and condenses any moisture there may be in the studio. This moisture runs down towards eaves, and any projections, such as tie-rod connections, are liable to arrest the water and cause it to drip off on to the floor or furniture. All such projections should, therefore, be bevelled off on under side, so as to lead the wet on to the roof instead of away from it. I saw in London not long ago a studio in which the roof and sides were in one continuous curve, bent glass and curved T-iron frame, work being employed. This gave a free, unobstructed hght, and the moisture was led right away to bottom of the side light. The proprietor spoke highly of it. Aspect. Nortli-west is undesirable imless high buildings happen to trap the afternoon sunshine. North by north-east is more suitable than due nortli, as tendency now is for people to come later in the day than formerly. As there is always the possibility of early sitters, it is ad- visable to have the means of screening the morning sun as well as that of the afternoon. I have zinc screens, about two feet wide, attached by brackets to the roof, running up each end and along the ridge. These are screwed up in the spring and taken down in the autumn. Zinc is better than wood. I was once nearly killed by a wooden screen being blown down piecemeal through the glass roof. About ten large panes were smashed. One board came through just where the operator had been varnishing some negatives. Amount of Space to be Glazed. Best to have enough, it can always be screened off when not wanted, and there are occasions when all possible light is required. The distance from floor at which side lights should start is a matter for consideration. My own begins at about three feet six inches from floor, and in a wide room this might do, but in a narrow one the glass might come down lower. Talking to a photographer the other day whose side light begins at about the same heiurht as mine, we both agreed that, if building again, we would make it lower. Short curtains running on wire can be used to screen the bottom portion. When young children are taken standing on the floor, it is difficult to get sufficient light en the legs unless the side light is low. , Kind of Glass to Use. In the roof I have used Hartley's rolled, and like it very well. It certainly cuts off more light than clear glass, but it diffuses what passes through, which compensates for any cut off. There is a good deal of colour in some samples, which are therefore to be avoided. If building again, however, I should be inclined to try ground glass. Hartley's is pretty strong, and although the street urchins are fond of making a target of the roof, and several panes have been cracked in the course of a few years, it has not been found necessary to replace any. in the side I have " white cathedral," which gives a pleasant illumination, but does not diffuse the light so well as "ground." Working in a studio on ground floor, having clear glass in side, the window looking out on to a grass plot, with a one-storied building about twenty feet away, the lighting was found to be hard, and was much improved by fixing up ground glass inside the clear for about two-thirds of the distance up the sides towards eaves. If the side light is quite unobstructed and likely to remain permanently so, and studio not overlooked, then, provided the outlook is pleasing or interesting, a certain amount of glass in the side might be left clear — it affords occupation to sitters or their friends to look at while waiting, and where several negatives have to be taken this is an advantage. For lighting, however, I prefer ground or Jigured ylans up to level of head of standing figure, and above that clear or " white cathedral." As figured glass is expensive and not strong enough for outside use, I should be inclined to glaze the whole of side with "white cathedral" or similar kind, and then have an inside casing of figured about two- thirds the way up to eaves, this to be so fixed that it could be removed or slid along for occasional cleaning. Clear glass could be left at intervals for outlook if preferred. Blinds. Whether these should run vertically on spring rollers or horizon- tally on strained wires depends on individual fancy, and on the way the tie rods are fixed. I have some of each kind. The chief, in fact only, objection to those running on wires is that they have to be moved with a long stick, which invariably causes sitters to look up at the skylight, and they then begin to realise that the light is strong, and perhaps find their eyes dazzled. Those running vertically, moved by a string, do not seem to have this drawback. With those running horizontally more graduated lighting can be obtained. Tie Rods. These are generally necessary evils. They are apt to be in the way of blinds, &c., and, unless eaves are high and the ties arched upwards, they prevent anything in the way of head screens being conveniently used. Screens such as recommended by Mr. Whaley in a recent " Annual " cannot be used if the tie rods are low. The places for these should be well thought out beforehand, so that, instead of being in the way, they may be made use of for hanging a swing or hammock from at a suitable distance from background. When I built one of my studios, not having had much to do with actual building operations, I wanted, as far as possible, to dispense with ties. Builder thought he could manage with two up in the roof only, not braced to the sides, with the result that, as soon as men began putting the slates on, the walls began to spread out, and we had a narrow shave of having to build twice instead of once. They were got back nearly into the original position, but not quite, and the wooden framework of side light remained somewhat twisted. For- tunately there was no glass in, or it would have been smashed. We then had to put ties in where we could, with tlie result that tho.s© attached to the sides did not correspond for position with those in the roof, and rather interfered with the working of blinds. In the matter of choosing a builder, it will be found cheapest in the end to go to the best, preferably a local one, who can be fetched back to make good anything that may not have been done just as it should have been. Coming as a stranger into the town, I thought it would be better to employ a man I had some acquaintance with (a non-resident) rather than take my chance of getting hold of a good one amongst strangers. I made a bad spec. My friend (?) used poor mortar, did not put any damp courses to the new work, put up & gutter to small too carry off the water properly, and fixed it up badly. This side being close to neighbouring property, the gutter had to be kept back flusli with wall, so he jiist bedded it on top of wall with ordinary mortar, consequently it overflowed inside as well as out. I had to call in another builder, who raised the wall to form a parapet, and put down a proper lead gutter. The parapet is a great convenience, as, when we want to get on roof to fix stove-pipe, put on a new slate, fix up .the zinc sun screens, or mop the glass, we can walk along without having to ask permission to take a ladder on to adjoining property. Materials foe Walls. If on own property, or such as there is a long lease on, it is best to have brick — -at any rate, if building is at all exposed to the sun's rays — and, if one cares to afford the luxury of a tiled roof, the room will be all the cooler for it in summer. If sheltered from the sun, wood and iron will do, provided there is good convenience for keeping it warm and dry in winter ; if exposed to sun, an iron building is decidedly hot in summer. Ventilation. I had arranged with the builder just mentioned to have good-sized ventilators in the gable ends, but he forgot, and persuaded me to rest content with a couple of air bricks. Result : operator and sitters baked. Next spring air bricks were replaced by a good swinging ventilator at each end, and the studio has since been no hotter than the generality of such buildings. 360 ITLE BRITISH JOURNAL OF PHOTOGRAPHY. [June 9, 1893 Wabming. Hot water from a Loughborough boiler heats all the jrooms on ground floor, studio itself being warmed by a tortoise stove Hot water savos a vast amount of mess and dirt, besides being more econondcal, and, provided the stoker is intelligent, leaves little to be Sr If, however, the stoker has a fancy for getting the pipes nke and hot on a mild day, and letting the fire out when the weather rschmy, the surplus heat" cannot so quickly be got rid of by opening windows and doors, nor the room quickly warmed, if cold, as when Tstovrin the studio is the source of heat If a stove is used, the fewe bends in the pipe the better. I used formerly to have the pipe tro straight up through the roof, and the stove always drew weU, ^^v^rr&ng sweeping all the winter through, a dight tapping on the pipe being sufficient to shake the soot down. Having moved it to a fresh place, necessitating a bend or two m the pipe, the moisture, which gets into it during the night in damp, foggy weather, cakes the soot, and necessitates frequent sweeping. , ^i, » Thanks to the ventilators at each end near the top, any smoke that may be puffed out when fire is first lit can be readily got nd of. However full of smoke the room may be, by opening the various doors and ventUators it can be aU blown out in abaut five minutes, and a clear negative taken. It is a great convenience to have a good supply of gas near the stove from which aBunsen can be supplied to light up fire quickly when required. For small rooms, or branch places not open perhaps everyday in the week, the new hot-water apparatus heated by paraffin should answer well if means are adopted to lead away the products of combustion into the outside air. Under any circumstances it is advisable to have stoves shut oH from the printmg department. Unfortunately, in my case, the only access to the Loughborough boiler is through the printing room, and the number of black spots due to coke dust that we get on our vignettes during the winter months is somewhat alarming. Doubtless, ■where it is necessary to heat rooms on different floors, a high-pressure boiler will do it most satisfactorily, but of this I have no experienca Some insnrance companies, I believe, decline to insure studios heated ■with water at high pressure. W. C01.K8. PRACTICAL REMARKS ON PHOTOGRAPHING DIFFICULT INTERIORS. II. I.N a previous article I referred to a few of the different kinds of interiors an operator is sometimes called upon to deal with, and instanced a few of the chief points necessary in dealing with weU- lighted subjects, where it was possible to bring into one's aid diffused light. There are very many other cases, however, where the light is so poor as to require extremely long exposures — ranging from hours to days, even when using plates of the most exalted sensitiveness,instances of "which will be found in warehouses under dark arches, such as are only lighted by large windows or doors at one end, and where the interior runs a long way back from the light. This class of subject is generally to be met with in large cities, where the arches under the railway lines are utilised for warehouse purposes, such as bonded stores, and many other similar businesses. I have known cases where, an exposure of twenty-four hours proving insufficient, a further ex- posure of from two p.m. on Saturday until ten a.m. Monday yielded a satisfactory negative, using a stop equal to /-22. One item of paramount importance, when giving such long exposures, is the utmost certainty of the camera and all its fittings being absolutely light-tight; and a further cause of failure, which I have never seen pointed out or referred to by writers, is the necessity for the plates being the full size of the cells. I have known cases where plates, being cut too small in their breadth, although right as to their length, gave no end of bother even to find the cause of failure ; when such happens, the Lglit plays round the back of the plate, and proves disastrous, the appearance of the plate being as if badly fogged. Another frequent cause of failure is using a lens too wide of angle for the camera, or dimensions of plate being used, whereby the sides of the camera re- flect light on to the front of the sensitive plate. Wide-angle lenses, however, are a necessity for this kind of work, but they should be carefully selected, to suit the size of plate being used. I sometimes feel platemakers have a deal to answer for in the careless manner they cut their plates to sizes, and when any one experiences, as I hare done, the annoyance of a plate being just so small as to allow of one side of it being pushed forward of the rebate in the slide by the pressure springs, ne will know to his cost how necessary it is to examine carefully every cell before leaving the dark ' room. This is especially the case when using large-sized plates, such as 12 X 10 and upwards. When a plate is cut too small, it is just about a hundred to one the withdrawal of the shutter of the slide will cause a scratch line straight across the face of the plate, and, worst of all, when the shutter of the slide is fully drawn, the pressure springs of the slide will push forward the plate, and prevent the door of the cell being reclosed. A more exasperating trouble cannot fall to the lot of any one. But these troubles are not only confined to interior work, they happen at Till times ; still, after having exposed a pkte upon a difficult subject for, say, forty-eight hours, it is doubly annoying to have to go all over the routine again. It is highly important that the plates tit the cells thoroughly. With camera and sUdes all being in perfect order, an operator has the utmost confidence that, even with the most prolonged exposure, his plate will develop up free from veil or fog. A very necessary precaution, however, is the backing of every plate with a coating of asphalt dissolved in benzole, as described by me in a former article on photographing stained-glass windows. This should never be omitted where very long exposures are being made, and any extra trouble expended in preparing the plates is more than compensated for by the results attained. Later on I hope to refer to the development of such long exposures. In very dark interiors, such as I have just referred to, it is almost impossible to over-expose a plate when properly backed with a preventive against halation. 1 am a firm believer in utilising daylight for all exposures when at aU practicable. There are many instances, however, where artificial lighting may be employed in combination with daylight. This I hope to refer to kter on. Daylight, with plenty of time, however, will be sure to make its presence felt on the sensitive plate, and, as a rule, yield the most truthful representations. In some cases isochromatic plates are a distinct advantage, but they should be used with considerable forethought, according to the nature of the subject. In dealing with large en^e shops, where the entire structure has to be included, prolonged exposures will generally be found necessary, and a time selected when the works are quite free of smoke and dust. I have known cases where some parts of the machinery required, under similar conditions of plates, stops, &c., an exposure of only twelve minutes, whilst the entire workshop was not overdone when exposed from early morn till dark, the cause being that the portion of machinery was situated somewhat near to a large window. When operating on machinery a considerable amount of preparation is necessary. This includes the colouring of the various parts, and toning down unduly bright portions. As a rule, however, in every well-appointed engine shop the makers and workmen are quite alive to the necessity of such, and generally arrange for this being done before sending for the photographer. Badly situated windows must also be dealt with, and one of the best means of doing so is by hanging outside the windows large tarpaulins ; this should never be neglected, and, although to any one unaccustomed to this kind of photography it may appear a lot of heavy work to arrange for such, still, in engine shops and other similar cases, the workmen are quite accus- tomed to face far heavier preparations than the mere handling of a few waggon covers, or the placing of such in suitable positions. I never yet met a case where the utmost willingness was not shown to assist in and carry out every necessary preparation. Engine work, as I have said, differs very much from all other branches of photography, and, before a young ojierator undertakes the responsibihty of such, he would do well to put in some experience with one accustomed to this special class of work. On doing this he will at the outset feel that he is, as the Yankee says, dealing with the " big in everything ; " he wUl soon, however, come to learn that what previously appeared an almost insurmountable obstacle was easily removed by a few wUling hands, which are always to be found ever ready th help, and this will soon engender confidence. It is seldom, however, especially in the case of photographing machinery, that negatives can be obtained sufficientfy clean or free from adverse surroundings as will permit of their being printed from without a considerable amount of prepara- tion. This to a very great extent means the necessity of blocking out such parts as could not be dealt with in the preliminary arrangement before taking the negative. In striking contrast to large engine worlis will be found such subjects as interiors on board ship. Of course there are large and small ships ; but, even in the case of the newCuiiarder Campama, there are very many interesting parts so cribbed and cramped up for space as makes it a matter of extreme difficulty to overtake. Of course, the magnificent dining saloon, capable of seating about 450 passengers, is one of the big things, and so are many of the other points of interest on board, in- cluding the funnels, which are over twenty-one feet in diameter, and large enough to permit an express train to pass through as it were a June 9; 1893, IIIE BRITISH JOURNAL OF PHOTOGRAPHY. 861 tunnel, are things that require a pretty bip: plnte and wide-nngle lens to •do tliem juetice, hut the cramped and cribbed subjects on board are the alley wavs, state rooms, pantries, &c. To photograph such was a matter of no little diiliculty. So, also, was the library ; although one of the features of the ship, and a magnificent room it truly is, still it gave me no end of bother togt't a good result. This delicious retreat is built some- what in the shapeof a horseshoe, and the semicircular bookcase, entirely filled with a most careful selection of booksjCorresponds in shapeexactly to the curve of the structure, every portion of which, at short distances apart, has little windows entirely round its sides. These windows throw a beautifully soft light into the room, but for photoCTaphic purposes — oh, what a horror! — every light is reflected back from the glass window in the bookcase. Screen oflf the windows, away goes the light. After much thought, however, I hit upon a plan which worked admirably, and, although I did not succeed in getting all the bookcase into the view, still, by cutting off the light all rouni ■one half the circle of the structure, and by blocking out the windows, I was able to 'get rid, to a very great extent, of the objectionable flaws in the bo, 3"i, and 20') 307 288 Number of fields photographed for the chart A 172 Number of fields photographed for the catalogue 271 Total number of fields photographed since the commencement of the work for the chart 176 Total number of fields photographed since the commencement of the work for the catalogue „ 299 It has been made a practice to take a trail on each night on a catalogue plate as a check on oneutation, and during the past year 127 plates with trails have been thus secured." Among the negatives shown were several illustrative of the effect of prolonged exposures, the latter as compared with (comparatively short exposures enormously multiplying the number of stars photographed. Miscellaneous Photoobaphs. The following miscellaneous photographs (included in the total number of 722 given above) have also been taken : — Nova Auriga), 49 ; for zero of scales and orientation, 36 ; North Pole (for adjustments of eiiuatorial), 11 ; Pleiades, with various exposures, 19 ; Victoria comparison stars (for determination of scale value), 12 ; lunar 362 THE BRITISH JOURNAL OF PHOTOGRAPHY. [June 9, 1893 eclipse, 1892, May 11, 4 ; comet Holmes, 2 ; moon, 3 ; Saturn, 5 ; con- iunction of Saturn and y Vlrginis, 16 ; trails of equatorial stars, 3. Four of the plates of the Pleiades have been taken with the group in four different positions on the plate for determination of the optical dis- tortion of the telescope. Some experimental plates of Jupiter, Saturn, double stars and lunar craters have also been taken with the image enlarged about fourteen times by a secondary magnifier, consisting of a triple commented concave lens of one and three-eighths of an inch in diameter and three inches focus, supplied by Mr. T. E. Dallmeyer. The results are very promising. The PHOTo-nELiooKiPH. The telescope and camera of the Dallmeyer photo-heliograph were again removed on September 9, 1892, from the wooden dome, where the new buildings obscured the horizon, to the first floor of the new museum, where they were remounted on stand No. 3, which was simply placed on the floor and found sufficiently steady. From this position it was possible to photograph the sun during about two hours each day. The instrument and stand No. 3 (the proper stand No. 4 having been lent for use in the eclipse expeditions) were taken back to the wooden dome on April 7, 1893, the sun being then visible over the roof of the intervening building. In the year ending May 10, 1893, photographs of the sun have been taken with this instrument on 180 days, and of these 410 have been selected for preservation, besides twenty-two photographs with double images of the sun for determination of zero of position. The photographic telescope presented by Sir Henry Thompson, which has been mounted on the Lassell equatorial, has been in regular use as a photo-heliograph since January, 1893, and photographs of the sun have been obtained with it on eighty-nine days, of which 158 have been selected for preservation. In all, with one photo-heliograph or the other, a record of the state of the solar surface has been secured on 220 days during the year. A new enlarging lens by Messrs. Boss & Co., which appears to be very free from distortion, was fitted to the Thompson photo-heliograph on December 13, and has been used regularly since for the eight-inch photographs of the sun. For the year 1892 Greenmch photographs have been selected for measurement on 197 days, and photographs from India and Mauritius (filling up the gaps in the series) on 1G5 days, making a total of 362 days out of 366 on which photographs are available." For photographs of sun spots an exposure of u^j of a second is given. Magnetic Obsebvations. The following remarks as the value of photography in magnetic obser- vations will be read with interest. "The photographic registration of the variations of magnetic declination, horizontal force and vertical force, and of earth currents, with the accom- panying eye observations of absolute declination, horizontal force and dip, are maintained as in former years. The period has been one of great magnetic activity, and at such times we can appreciate the advantage of the newer photographic processes, as compared with those of earlier days, in the clearness and delicacy of the registration of the many rapid mag- netic movements that occur during magnetic storms. There is also greater general certainty in the photographic work, the loss of register due to photographic failure being now a very rare circumstance." Eecent Sunshine. Photographers may like to know what the Greenwich authorities have to say over the recent remarkable summer weather : " The sunshine registered in the months of March and April has been phenomenal. For March it was 155-1 hours, and for April 231-0 hours ; the greatest numbers for these months in the sixteen years 1877-1892 being 141>i0 (1880, March) and 196i»-3 (1892, April). The greatest values for any month in the sixteen years preceding are 277'''1 (1887, July), 267'' 1 (1877, June), and 237''-8 (1882, May) ; and, if we consider the ratios of sunshine to the total time the sun was above horizon, or to the total time, less one and a half hours each day, during which the sun is too low to give a record on the paper, we find that April, 1893, was the sunniest month yet recorded." Eatio to Total No. Total, less of Hours- IJ boors daUy. 1877, June 0-640 0-594 1882, May 0-493 0-546 1887, July 0-558 0615 1893, April 0-557 0-624 A NEW SOCIETY --THE NORTHERN PHOTOGRAPHIC AND SCIENTIFIC ASSOCIATION. When- a number of amateur photographers and scientists residing in- the more northern suburbs of London decided upon the formation of a society which should prove of greater scope than photography alone could provide, the pleasant and now largely populated village of Wood Green was universally selected as the site of its headquarters. Wood Green in- itself has many amateur photographers and others devoted to scientific pursuits, and these have during the past few weeks being doing advance work in the formation of a society which should embrace not alone photography but other sciences more or less cognate to it. Wood Green, from having a short time ago been an outlying and very small suburb of London, has now become a species of centre, having suburbs of its own, the preponderance of its male inhabitants being engaged in London in business during the day. It is in continuity with Noel Park, Hornsey West Green, New Southgate, and similar populous districts. The inaugural meeting, which assumed the form of a conversazione, took place in the Public Hall, Canning-crescent, Wood Green, on Wednesday evening last week. The Hall was crowded, many ladies- being present. On the tables around the HaU numerous microscopes, showing objects with plain and polarised light, were arranged, together with curios from China, Japan, India, Africa, and the South Sea Islands, lent by medical men and others of the neighbourhood. The walls were decorated with photographs, both of a pictorial and a scientific character. A twelve-foot screen at one end, and a lantern in the middle of the Hall, left no room for doubt as to what one part of the entertainment was to consist of, and which eventually was found to be a display of a selection from Mr. F. P. Cembrano's choicest slides. Mr. J. G. Robins, the President of the Association, occupied the chair, and in course of his remarks spoke of the future of the Society that had just come into existence. Two preliminary meetings had been already held, and that night it was to be launched out to take its chance among the many others of different kinds that already existed. This Society was a scientific as well as a photographic one, and the person who took a practical interest in it found himself perforce dabbling in chemistry, and several other sciences. The promoters of this Society were a few gentle- men who were scientists, and who thought that a very good society could be formed in the district. The audience could judge for themselves as to the success of the inaugural meeting. The aim of the Society was to unite photography and other sciences together, which was plainly de- monstrated that evening by a glance round the hall. The speaker then went on to enumerate the various collections they had lent them that evening, speaking in very kind terms of the gentlemen who had so be- friended them, and expressing the gratitude the Society felt towards them for their kindness. He also spoke in eulogistic terms of the Secretary, Mr. A. S. Murrow, of the hard work that had devolved upon him in that capacity, and of the efficient manner that he had performed his various duties. The Society was indebted to Mr. Murrow for the handsome screen they saw before them, which w as in every respect one of the best that it was possible to get. Mr. Murrow had made them a present of it, and his kindness had been greatly esteemed. With regard to the lantern and photographic slides that would be exhibited by Mr. P. D. Coghill a little later on, the Society owed its thanks to Mr. Cembrano, of Richmond, who had sent, for this occasion, the finest photographic slides it was possible to obtain. Those present would soon have an opportunity of judging for themselves as to the accuracy of his remarks when the slides were projected on the screen. The speaker then went on to announce that the next meeting of the Society would take place that night three weeks, on which occasion a lecture would be given by Mr. C. Coulter on ChemUtnj on Dry Plates. After supplementing several additional fixtures, the speaker concluded his remarks by urging all his heaj-ers who took an interest in any scientific pursuit of any description, to give in their names to the Secretary, who would cordially welcome them on behalf of the Society. The Treasurer, Mr. F. K. Beagley, said that the Association was not being run as a paying concern, and all that was required of it was that it should pay its own way. In view of this the subscription was not a heavy one, namely, ten shillings a year ; and this was very reasonable considering the programme that was in store for them. The exhibition of Mr. Cembrano's slides, each of which was greeted, with encomiums, was followed by a similar exhibition of microscopic projections on the screen. Music, including madrigals, formed an attractive feature in the proceedings, and as some of the members and their lady friends are professional musicians, this element was ably- conducted. ».une 9, 1893] THE BRITISH JOURNAL Oi PHOTOGRAPHY. 868 The committee of management deserve unqualified thanks for the able manner in which everything was carried through. Tlie membership is very numerous, and the Association has our best wishes for its success. PHOTOGBAPHIC SALON, 1893. The following are the particulars of the Exhibition of Pictorial Photo- Braphy, to be hold at the Dudley Gallery, Piccadily, from October 9 to November 11, 18',>3. 1. An Exhibition of photographic pictures, to be called the Photo- graphic Salon, will be held at tbc Dudley Gallery, Piccadilly, London, W., from October 9 to November 11, 1893. 2. Careful consideration will be given to all pictures entered for exhi- bition, and a selection of works of pictorial merit only made by a Committee. 3. Foreign as well as English photography will be represented. 4. The aim of the organizers of this, the first Photographic Salon, is to inaugurate a series of Exhibitions (which it is hoped may be annual ones) bringing before the public the best productions of photography solely from the pictorial point of view. ,5. No awards are offered, and no charges made to exhibitors. G. The usual charge of 1«. will be made to the public for admission. Exhibitors will be entitled to a season ticket 7. Arrangements will be made for the sale of pictures, if desired, and a commission of fifteen per cent, will be charged on sales effected. Particulars as to price and sale will be printed in the catalogue. 8. Each picture must be separately framed, and each frame must bear oa the back name of exhibitor, numler and title of picture, and price if offered for sale, corresponding to the particulars on the entry form. This information must also, for catalogue purposes, be repeated on a label attached by a string, and made to hang over the front of the frame. y. The form announcing intention to send picture should be forwarded as soon as possible, and not later than Friday, September 1. The entry form must be sent with, or previous to, exhibits, and received not later than Wednesday, September 27th, addressed to the Secretary, Photo- graphic Salon, 215, Shaftesbury-avenue, W.C. 10. Pictures sent in packing cases, &c., must be delivered, carriage paid, at 215, Shaftesbury Avenue, W.C, not later than Wednesday, September 27. Frames delivered by hand must be left at the Dudley Gallery, Piccadilly, on Saturday, September 30, and removed, after the Exhibition, from the same place on Monday, November 13. 11. The Committee will unpack, repack, and deliver to carriers all exhibits sent in cases, but will not be responsible for damage. Every care will be taken of exhibits. To avoid damaKe, frames should have no projecting nails. 12. Intending exhibitors are desired to fill up the forms of advice and entry, and to forward the same to the " Secretary of the Organizing Committee, Photographic Salon, 1893," 215, Shaftesbury Avenue, London, W.C. , in accordance with the instructions noted thereon. NATIONAL ASSOCIATION OF PROFESSIONAL PHOTOGRAPHERS. May 26,— Council Meeting— the President, Mr. Thomas Fall (London), in the chair. Present : Messrs. Birtles (Warrington), Warwick Brooks, Hon. Secretary (Manchester), Crosby, Hon. Treasurer (Rotherham), Eddison (Barnsley), Higginson (Bowdon), Whitlock (Birmingham), Yates (Sheffield) ; also as a member of N.A.P.P., T. N. Longton (Sheffield), and D. J. O'Neill, Secretary. Telegrams and letters of apology were received from Messrs, Bromwich (Bridgnorth), Gill (Colchester), Mclver (Leeds), Slingsby (Lincoln), Whaley (Doncaster). Secretary's report was read, and the business transacted may be summarised as follows : — Annual report and statement of accounts, also list of the new Council elected at the annual meeting had been forwarded to the (14G) members. Next annual meeting will be held February, 1894, Birmingham. A dinner to be arranged for the members and friends on that occasion, details of which will be duly announced. Members of Council and members of the Association had paid over to Guarantee Fund for working the Association, 35?. . New members elected by vote of Council, Mr. Lyd. Sawyer (Newcastle on-Tyne), Mr. A. HoUis (Barrow-in-Furness). Several members not having yet paid their 1893 subscriptions {IQ.i. M.), Council requested that same may be forwarded to Secretary, D. J. O'Neill, [ 47, Charlotte-road, Birmingham, as speedily as possible. Secretary continues to receive communications of various kinds from all parts of the world, evidencing the fact that the N.A.P.P. was now fully recognised as the official representative of the profession. The Photographic Convention of the United Kingdom will be held at Plymouth, July 3, 1893. Mr. Coles (Watford) had kindly sent a list of proposed members to Secretary. The various uses to which the Association might be applied (or the benefit of the profession had been frequently referred to in the photo- graphic press. The establishment of a Photographic Club and Institnte was hesrtily approved by the Council, and it was noted that the President, Mr. T. Fall, had been requested to act as a member of the Provisional Committee of the Club. Respecting the very important case of the most unjust proaecation of Mr. Cowley, the Secretary gave full particulars of the correspondence on the subject between infiuential members of the N.A.P.I'. It was felt that, while every member of the Association heartily sympathised with Mr. Cowley, the Association was not in a financial position to take up his case and to isstitute legal proceedings on his account, especially as he tcag not a member of the Assoriatio^i, Council recognised gratefully the active part taken by the President, Mr. T. Fall, in this matter, and he detailed the action which he (Mr. Fall) was taking for the benefit of Mr. Cowley on his own responsibility, and without in any way com- promising the Association or its friends. A desire was expressed that the members should send in to Secretary suggestions and designs for the proposed " Certificate of Membership," which it was agreed at the annual meeting should be issued to members. Referring to suggestion from Mr. W. P. Marsh (Bognor, Sussex) as to traders and manufacturers supplying members on special advantageous terms. Council was of opinion that the present members (146) of the Association now warranted their demanding such advantageous terms for the Association. The President kindly undertook to procure data as to the terms on which makers and traders would be wilUng to comply with this very reasonable request of the Council. Mr. R. Slingsby (Lincoln) having brought forward the subject of cer- tificates of skill and capacity to be issued to assistants, the President dwelt at length on the very unpractical character of the certificates now issued by the London Polytechnic Institution, which were merely good for a limited chemical knowledge. Council expressed strong wishes that some system should be adopted to bring really capable and duly qualified assistants within reach of the professional photographer. Secretary was instructed to communicate with Secretary of Polytechnic Institution, with a view to some arrangement that before such certifi- cates were issued, students should be examined by some representa- tive, capable, and experienced photographer. In reference to the comments of Mr. Battcrsby (Manchester) on the sale of methylated spirit, Council considered that there was now no practical difficulty in the way of photographers procuring same. The President stated he should be happy to assist all members in this matter, and to give them the advantage of his knowledge and experience on the subject. The President reported his intention to visit the Chicago Exhibition Photographic Conference as requested by the Council. Mr. Eddison (Barnsley) brought forward the subject of the present unjust mode of dealing with photographers by the fire insurance com- panies, as regards compensation for loss of negatives. He spoke from painful and personal experience in the matter, and stated that instead of the person insured recovering the amount which he was insured for, the insurance company only paid on a " proved average of the actual sales from negatives in stock over a given period," making the amount refunded about one-fourth of that on which the insurer had been paying all along. The Secretary was instructed to communicate with Mr. Eddison and his assessors, Messrs. East & Haslam, Leeds, with a view to procure some alteration in this most unjust mode of procedure. The next Council meeting will beheld at Anderton's Hotel, Fleet-street, at the time of the opening of the Pall Mall Photographic Exhibition, London. All professional photographers will be gladly welcomed by the Council. ©ur IBtritorial JTaijIe. Qltcin-Hauff. Fuerst Bros., 17, Philpot-lane, Last week we acknowledged receipt of a sample of the newest developing agent, and since then we have had an opportunity of putting it to a trial. Its salient qualities are thus indicated in the makers' instructions. " Glycin-Hauff, with potash, forms a developer giving, without the addition of bromide, absolutely clear and trans- parent negatives of an agreeably grey colour. It is not a rapid de- veloper, hut works slowly, with great harmony and softness. An advantage not to be under-estimated of this developer also consists in its great keeping quality, which will not alter if the solution is sufficiently concentrated and in well-closed bottles. The concentrated developer is made up as follows: — 350 grains of sodium sulphite crystal are dissolved in one ounce of water, 150 grains of glycin are then added and heated to boiling point, and one and a half ounces of potash carbonate are added (begin adding the potash in small quanti- 864 THE BRITISH JOURNAL OF PHOTOGRAPHY. [June 9, 1893 ties, on account of the carbonic acid gas). When cold, this con- centrated developer — forming a thin, pasty solution — may be kept as stock. For use, shake the solution first, and dilute the required quantity twelve times for ordinary purposes. For use when de- velopment is to be left to itself, the stock solution is diluted fifty times," In our own experiments, we made up for use the following solution : — Sodium sulphite 40 grains. Glycin 20 „ Potassium carbonate 80 „ Water 4 ounces. Using this solution as the working developer, we found that, although its action was comparatively slow, with rightly exposed plates it yielded a charmin municalions through the post. %* Communications relating to Advertisements and general business affairs should be addressed to Messrs. Henry Greenwood k Co. , 2 York-street, Covent Oarden, London. *,* It would be convenient if friends desiring advice respecting apparattis, failures in practice, or other information, would call at the Editorial Office either on Wednesdays from i to 6, or Thursdays from 9 to 12 noon, when some one of the Editorial staff will be present. Photographs Registered : — W. Crow Gordon, Nairn.— Pho(osrapHo/JSli« o/ U.R.H. the Prince of WnUf revifirina lii» otrn Yfoinanry Re<^immt ujion Rowtdtcay Ifill, Dtviutf and upon tht occatioii of the H'Utthirt ¥«omnnnj Ctfnttmary. » W. OlBUNO. — Thanks for yours and enclosure. Binocular. — Screw the lenses on the front, so as each to be in the centre of its half of the plate. PniNTEii.— By hoilin? the water, and using when cold, the deposit on the prints will probably not recur. K. — Any good lens of the enryscope class will serve your purpose. The one you sjiecially mention belongs, we believe, to that class. ALmED BoEHM (Burton-crescent). — The agent for Gunther Wagner's trans- parent colours is Mr. C. A. Rudowsky, 3, Guildhall -chambers, E.C. G. B. — Tlie lenses of Lerelmura et Secretan are generally considered good. We do not know the present commercial value of one suitable for whole-plates. P. Newman. — Registration enables you to proceed for infringement of copy- right. The latter lasts for the owner's lifetime, and seven years after nis death. C. J. Emenv. — In the advertisement pages of the Joubxal and Almanac, you will find every type of camera dealt with, some of which you will no doubt find suited to your purposes. C. Y. 0. — Unless you have a copyright in the picture, you cannot prevent its being sold at any price the pirate chooses. It is certainly annoying, after having paid a high price for the negative. (iRamme. — Weights and measures on the metric system can be obtained from any of the dealers in chemical appliances ; or any of the photographic dealers would supply them to order if they do not stock them. W. Heming.— If the prints, after being removed from the toning bath, are first subjected to a good dxsh of water, and are then transferred to fresh water, the toning action will not be continued. This, at any rate, is our experience. E. Myers. — Bichromate of soda is not so good as the bichromate of potash for sensitising carbon tissue. It has been recommended for the purpose, but it is founil not to answer so well, as it has a tendency to render the tissue quickly insoluble. Novice. — There is no necessity to boil the starch for raoauting purposes. In fact, it is not so good if boiled. The want of adhesion in your case is, that the starcli was not rightly mixed. Get a little instruction in the matter from the domestic department. Madame Talbot Wilson writes : "May I ask if you could give me a list of the places in Rome, Florence, Venice, and other towns in Italy and Germany, where an amateur could develop negatives ? " — Perhaps some of our readers can supply the information desired. OxON. — Something must be radically wrong. Five grains of chloride of gold for each sheet of paper is out of all reason. As you are sure that none of the gold is reduced spontaneously, we can only suspect that the salt being em- ployed does not contain the proper proportion of metal. I Craven.— In copying oil paintings or water-colour drawings with plates orthochromatised with erythrosine, a yellow screen should be employed to obtain the best efl'ects. Its depth ought to be chosen according to the character of the work. It is well to be provided with two or three screens of different depths. They are not expensive in small sizes. A. C— It was very unwise to send the money for second-hand goods with- out knowing something about the advertiser. As more than a week has elapsed and the apparatus has not arrived, and you can get no reply to your letters, the matter certainly looks very suspicious. Therefore lose no time in communicating with the superintendent of police for the district, giving full particulars of the affair. Tyler.— The only way to obtain more detail in the darker parts of the interior of the church is by giving a longer exposure. Although twenty-five minutes may seem a long time to you, an hour and a half would not have been a bit too long, under the same conditions as to stop and plate, to get full detail in tlie deepest shadows. The light circle in the centre of the picture is a Hare-spot as surmised. ,', Benjamin.- Unless yon can prove that the negatives were badly packed, we thmk you have no remedy against the enlargers. As a nUe, they state on their prospectuses that they do not hold tliemselves responsible for breakages m transit. Tlie remedy, if any, would be against the carrying I agents. But the claim should have been made at the time. After so long a period they will, no doubt, repudiate it altogether. .. G. HiLLHODSE.—l. While the rates of wages for operators in the United I States may be higher than those here, it is the case that competition for the best positions is as keen, if not keener. 2. There is no such journal there, i <5. If you decided to start business there, we should suggest your going to a J small town, and growing with it ; but whether you would do better there than I here hinges so largely upon personal qualifications that we cannot hazard I any opmion on the question. A. Campbell says: "I have made up some collodion for enamelling, using equal parts of methylated ether and alcohol ; but it does not answer. The film it prorints sticking i." that the jilate was not Rufficiently treated with the French chalk — it was not rubbed sufficiently on the glass. H. A. — We should say that the pawnbroker will have to give up the lens, even if the thief is not caught and convicted. As only twenty-one shillings was- asked for on an instrument costing over twenty pounds, and Ijearing a well- known maker's name, the pawnbroker might well have assumed that it was come by honestly. That, we imagine, would l>e the view taken by the magistrate before whom he might be summoned. As the lens is a valuable one, it may be well, in the first instance, to consult a solicitor. PvRO (Leeds). — It is impossible for any one to give the exposure " for an en- largement on bromide paper from a quarter-plate negative with a lens work- ing at /-8 with daylight" It will depeml upon the sensitiveness of the paper, the density of the negative, the light at tlie time, and the degree of amplification. The liest way to ascertain what is required is, when aU is in position, to make trial exposures on two or three small pieces of paper, and then develop them. With a few experiments of this kind, proper exposures can soon be arrived at. C. Frith. — Your announcement was only received after the preceding portion of the Journal had been sent to press, but we insert here a synopsis. The Harriugay Society will, owing to an increase of member.*, hereafter meet at 8, Station-road, Finsbury Park. They will 0|>en with a concersa:.wne at the Public Hall, Finsbury Park (entrance, 14, Stroud Green-road), on Thursilay, the 15th iiist. Tickets of ailmission, 6(i. , to be had of local chemists. Secretaries of Societies would greatly oblige by sending their reports so as to reach us Ijefore Wednesdays. P. A . G. asks : " Whose place is it to keep a studio in repair, the tenant oi the landlord ? The tenant built the studio, removable at any time, some years ago in the garden, and the premises are held on a yearly tenancy. The landlord has always done the repairs to the house, and makes no demur to- doing so still, but refuses to repair the studio. Can he be compelled to ?" — We should think, certainly not. It is the tenant's property, and put upon the premises by him for his own use, and to be taken away whenever ho removes. We consider it is as unreasonable to expect the landlord to keep the studio, under these circumstances, in rejiair as it would be to expect him to repair the furniture in the house when it requiresit. H. T. writes : " A short time ago I bought a benzoline cask to store waste silver washings, The cask being full, I tried to precipitate the silver with common salt. Finding that it would not separate, tried sheet copper. Tliat not having the desired effect, I have come to the conclusion that the benzoline retained in the wood of casks stops the precipitation. Could you say if it is so, and suggest a remedy > In both trials the wa.shings have been given a longer time than usual to .settle, but it has had no apparent effect, except to slightly coat the copper. Have used jiarafiin casks before, and have had no trouble with them." — The cask is not the cause of the silver not subsiding. The silver in the wa.shings from some papers, particularly ready- sensitised, is more troublesome to predjiitate than from others. In these cases hydrochloric acid is a better precipitant than salt. Try the effect of adding an ounce or two of nitric acid, and then give a vigorous stirring for a few minutes. After this treatment the chloride of silver usually subsides- quickly. PHOToaRAPHic Club.— June 14, Members' Open Night, Manchester Photographic Society. —June 10, Alton (ramble). The Birmingham Photographic Company, Limited, have removed to- Criterion Works, Great Charles-street, Birmingham. We thank Mr, James Paton, 'Greenock, for an interesting photograph of a flash of lightning, obtained on the evening of the 20th ult. It was takea across the Clyde. Change of Address.— The address of Mr. Fred H. Davies, Secretary of the Talbot Photographic Album Club, Birmingham, will in future be 26£>, Coventry^ road, Birmingham. Leytonstone Camera CLua— June 10, "Up the River" to Battersea Park; leader, Mr. A. E, Bailey. The Club will proceed by the first boat after forty- five minutes past two p.m., from Old Swan Pier, London Bridge. Newcastle-on-Tyne abd Northern Counties' Photographic Associa- tion.— Out-door meeting to Ripon and Fountain's Abbey on Thursday, June 15. Train leaves Newcastle at thirty-tive minutes past seven a.in. Mr, H. 6. Ridgway, leader. We are sorry to see from the daily papers that Messrs. Iliffe & Sturmey, the proprietors of our contemporary Photuffraphij, have had two ca.ses of libel decided against them last week in respect of another of their publications, the IMcycling News. It is evident that some cyclists, to borrow our friend's language, have a less tough epidermis than others, hence these actions, which it is to be hoped will not be imjiorted into photographic journalism, some of which body occasionally sail abnormally close to the wind. 868 THE BRITISH JOUKNAL OF PHOTOGRAPHY. [June 9, 1893 Lks Paoc^Dfe MoDEUSEs d'Illustratiox. — Messrs. Thuvoz & Co., of Geneva, are issuing a small monthly publication, illustrated, dealing with modem photo-mechanical methods of illustration. The first number contains a brief article on "ancient methods," wood-engraving, lithography, and copper plate. Crotdou Camera Club. — Wednesday, June 14, Excursion, conducted by Mr. H. Maurice Page ; leaves West Croydon at thirty-two minutes past nine a.m. (vid C'lapham) for Weybridge. Saturday, June 24, Excursion, conducted by Mr. Maclean ; leaves East Croydon at three minutes past two p.m. for Edenbridge. London and Provincial PHOToanAPHio Association. — June 10, Saturday Outing, London Colney ; first train from St. Pancras after half past two. 22, Demoustration by W. D. Welford, Welford's Toning Bath for Chlm-ide Paper. 24, Saturday Outing, Chingford, for the Forest. 29, Annual Meeting ; ■election of officers. Oldham Photographic Socibtv. — June 10, Saturday, Rossett. Depart, ■Central, fifty-two minutes past eight a.m., for Rossett viA Chester. Return fare, about 4s. ; leader, Mr. W. Thompson. June 13, Tuesday, Belle Vue. Depart, Clegg-street, twenty-seven minutes past one p.m. Return fare. Is. 2d. ; leader, Mr. Tom Heywood. Photographic Society of Great Britain.— June 13, Ordinary Meeting, to be held at 50, Great RusseU-street, at 8 p.m. A paper will be read by Mr. William Taylor (of Leicester) on The Constriu:tion of Interchangeabh Lens- screw Fittings ; and Dr. C. P. Goerz (of Berlin) will read a paper upon, and exhibit, A Neii) Anastigmatic Lens. Lens Flanges. — It is already known that Mr. William Taylor, of Leicester, is to read a paper on this subject before the Photographic Society on Tuesday next. In this he will describe the method in use in the Slate-street Works for the accurate making of lens screw fittings. This he will do in the hope of ■improving the general condition of screw making, and all those interested in such mechanical work certainly ought to be present on that evening. Writing upon the recent conviction of a Chelmsford woman for cruelty to a child, the East Anglian Daily Times has the following remarks on the value of photography in this and similar cases : — ' ' The second point is the link in ■the chain of evidence which bound all the others togetlier, and made escape impossible. It was open to the defence to suggest perjury or exaggeration .against any number of people ; but, as Mr. Commissioner Kerr pertinently observed, the sun does not tell lies, and the happy thought of Mr. Kidd, in photographing the poor creature just as she had left her tormentor, removed all doubt from the minds of the jiu'y, who gave their verdict without leaving the box. This is a hint which may be commended both to the police and the Society's officers. Nothing would make the lame excuses for cruelty — which some people accept so easily — utterly futile more than an invariable practice of photographing the victims at the earliest possible moment." In course of some correspondence of a somewhat chaffing nature that was indulged in between Messrs. Alfred MaskeU and Cimabue Brown, jun., in this Journal in the early part of last year, a statement was made by the latter gentleman in which was voiced a belief that the author of a certain article refiecting on the Camera Club was a well-known optician, who, although un- mentioned by name, considered that his identity was unmistakable. As we have since then learned and believe that he had nothing to do with the matter, we can only express our regret that any statement which was calculated to give pain or annoyance to that gentleman should have appeared in our columns. While we allow the utmost freedom of expression to our correspondents, and not uufrerjuently have to tone down the force of their language, still may state- ments be allowed to pass which on intermediate inquiry would have cansed to be eliminated. This is one such case for which we apologise to the person aggrieved. Richmond Camera Club.— Summer programme, 1893 :— Informal Meetings, third Monday in month : June 19, July 17, August 21, September 18. On these evenings members are requested to bring prints from negatives taken during the Club excursions. Excursion : Saturday, June 10, Uxbridge, twenty minutes past two train from Paddington ; leader, Mr. Andressen. Saturday, July 1, Eyuesford, forty minutes past two train from Holborn Viaduct, or forty-five minutes past two from Victoria ; leader, Mr. Williams. Monday, Augu.st 7 (Bank Holiday), Oxted (for Limpsfield), forty-five minutes past ten a.m. train from Clapham Junction ; leader, Mr. Williams. Saturday, Sep- tember 2, Godstone (book to Caterham), trains from Charing Cross, five minutes past two ; Cannon-street, seventeen minutes past two ; London Bridge, ten minutes past two. N.B.— Those wishing to attend this excursion should inform Mr. C. H. Davis, 97 Church-road, Richmond, not later than August 28, so that a conveyance from Caterham Station may be arranged for. WATEB IN DEVELOPMENT. ■ In the process of development, the employment of ready-mixed solutions is customary. In pyrogallic acid, or whatever developing agent is used, we have an energetic reducing agent, i.e., one which is susceptible of oxidation. Air dissolved in the water here comes into play as an oxi- dising agent ; any iron present will tend to strongly colour the solution. The water, therefore, in this case, should be boiled and filtered before use. In the alkaUne solution almost invariably used in connexion with the reducing agent, the impurities are not so important, as the changes undergone on standing would be but slight. Alkaline reducing agents absorb oxygen much more readily than when in the neutral or acid state, hence the two liquids are mixed only at the time of using them, and a few drops of acid are added to the pyro stock solution to correct any alkalinity on the part of the water. Waste from paper mills or chemical factories discharging into the stream from which the water supply is taken may prove very serious at this point. Hyposulphite of soda is used as an antiohlor in bleaching, and even a trace of this substance in the developer leads to disairface deposit, it is well to apply gentle friction to each individual print. In the case of small pictures this is readily done with the fingers in turning them over, or they may be rubbed gently together in pairs, face to face ; but with large prints it is better and safer to lay them singly upon a sheet of * Concluded from page 355. glass and pass a soft sponge, a tuft of cotton-wool, well wotted, or a broad camel's-hair brush, carefully over the surface. The exercise of a little care in the minor details — even in so comparatively unimportant a matter as washing — will tend very greatly to improve the quality of the result, as well, perhaps, as the ultimate permanence of the prints, but particuliirly will it aid in securing uniformity of tone, not only in the same, but in successive batches of prints. Nothing is so likely to bring about an ojjposite result as imperfect or careless washing, for prints containing variable quantities of soluble matter are not only in themselves in an unfit condition for evenness of action, but they introduce into the toning bath substances which modify or perhaps entirely destroy its action. The washing after toning should be performed with equal care, although it need not be carried to the same length as the previous washing. On removal from the gold solution, each print should be freely exposed to the action of a considerable volume of water, either from a tap or in a vessel of large di- mensions, so as to at once arrest the toning action. If a large number of prints are removed in quick succession from the toning bath into a dish of water in which they have little room for the free circulation of the liquid, the toning action is certain to continue irregularly, with the inevitable result of patchiness. Where a tendency to softness of surface is exhibited, it is not well to use the alum bath too soon — that is to say, before fixing ; or very soon after, before the hyposulphites have been removed. As is well known, alum decomposes the hypo- sulphites, and should not therefore be allowed to touch the prints until the soluble salts have been, as far as possible, re- moved. In such cases it is far preferable to add a little sulphate of magnesia to the washing water, which should, of course, be kept at as low a temperature as can conveniently be managed. After a thorough washing in this manner, the alum may be used with perfect safety. In no case, except where prints are to be mounted in contact with glass, should the alum bath be omitted. One of the strongest objections raised against gelatino-chloride prints is the difficulty of liandling them in mounting, on account of the sticky character of the surface. But this is wholly due to neglect of the alum bath, which, if freely used, renders the gelatine surface as easy to manage as the ordinary albumen print. Indeed, a properly alumed gelatine print may be treated in precisely the same way as albumenised paper, even to drying it by heat. Those who have been accustomed to albumenised paper are very apt to be misled with gelatine paper into over-printing, owing to the comparatively slight reduction that takes place in toning and fixing. Where this occurs a convenient reducing agent is handy, and nothing seems more eflScient for the pur- pose than ferricyanide of potassium and hypo used very weak. When a print is seen after fixing to be only slightly over-done, it may be removed directly from the hypo into a dish of very weak ferricyanide solution containing only sufficient of the salt to very slightly colour it, allowing it to remain until the necessary reduction has been effected. Where greater reduc- tion is needful, the print should be preferably slightly washed after removal from the fixing bath, and then immersed in a dish of similar solution of ferricyanide to whicli a few drops of hypo solution have been added. The energy of tlie solution depends upon the former salt, which should not be used too strong or excessive action will take place. The reduction should be gradual, as it is then not only under more perfect control, but is more likely to be uniform. 372 THE BRITISH JOURNAL OF PHOTOGRAPHY. [June 16, 1893 The same means may be adopted in cases where from any cause the tone of the print is irregular. It very ofteu occurs that from misjudgment a print after fixing turns out to be under-toned, the half-tones having reached the cool grey stage while the shadows are still more or less red. In such cases the use of the ferricyanide will very often satisfactorily modify the tone, removing the warmer colour of the unaltered silver, but leaving the gold-toned image intact. Of course, for successful treatment in this manner, the print must be of sufficient depth to bear a slight amount of reduction, though the effect then produced is far less than might be expected, so far at least as toned image is concerned. In most cases the action more closely resembles a continuance of the toning than reduction or removal of a portion of the image as it really is. The Royal Weddingr.— It will be remembered that, last year, when the wedding of the late Duke of Clarence was announced, there was a great run on the portraits of the lloyal couple. An equal demand is now being made for the portraits of the Duke of York and the Prince-ss May. The sale of those of the Princess appears, it is said, to be in no way diminishing by the enormous number that were disposed of last year. A Kew Xiens. — The new double anastigmat lens, described and shown at the Photographic Society of Great Britain on Tuesday evening by its inventor, Dr. Goerz, of Berlin, appears, if we may judge from specimens then exhibited, to be a »tep decidedly in advance. From its large aperture it is entitled to rank as an aplanat ; it is free from astigmatism, and even with a large aperture it has a field that is quite flat. These valuable properties will ensure for it a cordial welcome when it comes to be introduced commercially in this country. It is only by a comparison of its work with that of other lenses formed of the Jena glass that its great advantages can be fully appreciated. Some details as to its nature will be found in the report of the meeting on another page. The Eclipse Photograplis. — The members of the Royal Astronomical Society have now had the opportunity of seeing some of the most interesting of the photographs of the late eclipse. At the meeting last week, with the President, Captain Abney, C.E., in the chair. Dr. A. A. Common, F.R.S., read the preliminary report of the Eclipse Committee, and some of the photographs obtained were described by Professor Thorpe and other members of the expeditions to West Africa and Brazil. At the same meeting some wonderful photographs of the Milky Way, and also of the comets Smith and Holmes, were exhibited on the screen by Mr. Barnard of the now famous Lick Observatory. What would astronomical science do nowadays without photography and the lantern ? The Katlonal AsBOCiation of Professional Photo- graphers.— It appears not a little surprising that this Society receives such scant support from the profession in whose interest it was formed. From the report given in our last issue it seems, although it has now been established some two or three years, it numbers less than a hundred and fifty members. It is obvious that, with this limited roll, with a half-guinea subscription, it cannot achieve much of what it was established to do. There is no question that a society of this description, if properly supported, might be of great service in protecting and furthering the interests of the pro- fession generallj'. Why, then, is it so little supported ? Is it because there is less unanimity among professional photographers than' there is with almost every other profession and trade, or is it that the majority of photographers are too lethargic ? It is noteworthy that the Association appears to receive more support from photographers n the prnvin^Bs thin it does from th isc in the metropolis. Xilg^ht In the Studio. — A question was raised recently at one of the Societies as to the proportion of light obstructed by the glass of the studio. An equally interesting question is the amount of actinism that is filtered out of the light by some glass, and the dirt that is frequently upon it. It is true that this is not such an im- portant matter now with dry plates as it was in the days of collodion, but still it is worth consideration. Some kinds of glass are very prone to turn yellow with prolonged exposure to light, particularly some of the whiter sorts that are often selected for glazing a studio. We have seen several examples that, after a few years' exposure, had become quite of a yellow tint, and cut off a considerable amount of actinism, as proved by their retarding action when laid on sensitive paper. The dirt that accumulates on the glass in the roof of the studio — particularly in large towns — is of a highly non-actinic nature , especially is this the case with that on the inside, when coal fires are used. From these causes the exposures, in some studios, have to be materially prolonged beyond what would otherwise be the case. The Award Troubles at Chicagro. — The trouble with regard to the awards at the " World's Fair " is at an end. This has been brought about by a compromise that has been accepted, with one or two exceptions, by all the foreign commissions. The com- promise is practically a surrender. The awards are now to be made by a jury, instead of upon the report of a single expert — the point of contention — as would have been the case but for the vigorous protests of the foreign commissioners, by the threatened, indeed the actual, withdrawal of the exhibits of something like a score of countries from competition. So far, we may hope the awards will be satisfactory, or, at least, as satisfactory as at most competitions. This gratifying result has been obtained mainly through the instrumentality of the Secre- tary of the British Commissioners, Sir H. Trueman Wood, whose opinion of Mr. Thacher's system, it is said, is still unaltered ; but the notice given on the subject was ample, and the acceptance of the American system was practically completed when the exhibits were sent. We have before mentioned that British interests were in good keeping in Sir II. Trueman Wood's hands. But, there, no ona ever doubted that. STUDIO-BUILDING.* IV. Before proceeding to the act of glazing, it would be well to refer tO' ventilators, a point upon which no branch of the subject gives rise to so great a variety of opinion. The popular idea of ventilation is that, as heated air ascends, if a hole be made near the ceiling of a room, the hot air will go out ; and a further elaboration of that idea is that, for this egress to take place, it is first necessary to make another hole near the floor for the cold air to come in. It too often happen.s under such circumstances that the air will come in at the top and go out at the bottom, the ventilation of a building depending upon such a variety of conditions, both internal and external, as to defy the production of any uniform scheme for self-acting ventilation. When mechanical contrivances are adopted to enforce the egress of air, it simply becomes a matter of paying the required cost and using judgment in selecting an apparatus that is likely to perform in a satisfactory manner. It would make this already long series of articles too long by far to enter into any details on ventilating ques- tions, and, as few photographers would be likely to go to the cost of providing mechanical contrivances, I would briefly say that my own experience has been that, practicallj', the greatest comfort is brought about by having as many windows as possible at the sides of the studio capable of being opened at will, and as many openings in the roof also, not forgetting that a close watch is required to be kept upon the latter against probable showers of rain. During hot weather as many windows and dooi-s will be kept open as conveniently can be. When the studio is overlooked, lattice-work can be placed outside the windows. One set of windows in my present studio is provided with obscured glass and lattice- work, the former opening outside, and the- * ConcluJed from jugc 291. June 16, 1893] THE BRITISH JOUKNAL. OF PHOTOGHAFHY. 673 latter fixed internnlly, the laths being inserted at a suitable slant towards tlie sitter. AU that now remains to be dealt with is the painters', f^lazier's, and decorators' work, and the designing and arranging suitable blinds. The glazier is usually a man of dogmatic turn, who "knows his own business," and resents interference. Painful experience has taught me that he is very far from being infallible, and, as touching the question whether he knows his busine>*s, it would be interesting to learn in how many studios in the kingdom he has displayed, or made use of, that knowledge so as to glaze a wood-sashed roof watertight. There are three main points in which his work may be overlooked First, the window bars should have by preference three coats of paint before being glazed (it goes without saying that the wood should be dry; no skill in glazing can counteract the evil effects of green timber). I have seen many, perhaps through the impatience of the owner, glazed when the wood has only had one coat of " priming : " this kind of work is almost certain to leak eventually. Second (this hint was given to me by a glazier who did know his business) it is greatly conducive to the production of a watertight joint to give a coat of paint along the margin for about half an inch on each face of the glass where the putty is applied. The facility of adherence, or " growlng-to," as they quaintly express it, between putty and glass is iticieased to a very remarkable extent, and, when this is done, the bars painted as described on a dry day, and good putty is used, tlie studio" builder need not have much fear as to future tightness of his roof' provided it be not disturbed or shaken while the putty is settinf. Tiiird, let there be contracted for, and care taken that the agreement is carried out, that putty of best quality, and free from water as an adulterant, is employed. This is very important, as water-weio-hted putty very soon becomes leaky. This part of the subject may now be dismissed by saying that the roof should he periodically inspected, decayed putty removed and replaced by new, and the wliole repainted every year or two. Un- fortunately, the best period of the year to do this is the busiest time — -irly autumn, when the wood is dry and before heavy dews have begun i'lrm, as in the latter case work has to be deferred till the sun dries tiie roof, and the painters' presence occurs at a time when they are more than the usual nuisance. With regard to the decoration of the interior of a studio, the pro- verb, " De gustibus non est disputandum," so strongly applies, that I should not think of laying down any rigid laws. It is often held that the unglazed walls of the studio aid, or should aid, in the general illumination of the sitter, by means of the light reflected from them on to the more shadowed portions of the figure. My present views are that, if the shadows are lightened, when needed, by specially applied reflectors of whatever material or fabric is preferred, there is greater control over the illumination of the sitter, and then the decoration can be done on its own merits. For a long while blue was conadered the proper colour for painting the interior of a studio ; but, fortunately, the plan has been mainly banished to the more elementary kmds of studios and workers. Still, remembering that the question of taste comes in, I would say, if the paper chosen for the waUs be dark, and not striking or garish in pattern — bright yellowish or reddish hues being avoided — the sitters' eyes will experience a degree of com- fort quite impossible when lighter and gayer patterns are chosen. The blinds com'e last under consideration, but they are by no means least in importance. Indeed, it is by judicious arrangement of them in designing the studio, and by artistic arrangement of them in use, that tlie whole character of the work is influenced. It is here where ;ae artist can show himself, and upon his control and power of con- . .1 over them will depend, to a considerable extent, the reputation of the professional photographer. Blinds are mainly worked on two broad principles— curtainwise and roUer-blindwise. 3Iuch depends on the construction of the studio and the various aspects under which the sitter may be arranged. Each has its advocates, and it is usually the case that a photographer, discussing the subject, is ardent in praise of the plan he himself adopts. For myself, I am not prejudiced, as I work both plans ; but I have a very emphatic preference for the curtain over the blind style. I have tried roUer-blinds and spring- blinds— the latter working up, and down, and sideways— and they have many advantage? : but .some' time or other the cords will go wrong, and, as a matter of course, we all know such disaster always happens at a most critical moment. I will first describe the curtain- blinds I use. Many artists use strong metal rods for suspending them ; others use wires. I have tried both, and I most strongly advise the use of the latter. They are cheaper, easier to erect, and they can be always rendered taut by the turn of a screw. My mode of fixing is to attach firmly into opposite walls, or other supports, a specially strong screw-hook for each end of the wire. The latter is, at one end, firmly twisted into a loop, and slipped on one screw-hook ; the other end is attached to a swivel screw, constructed on a similar principle to those in use for tightening each length of wire in wire fences. The swivel end rests on the second hook, and a few turns will make thirty or forty feet of wire as tight as a piano string. These wires are laid in pairs along the lower part of the under side of the glass roof, and at a certain height they are made to run horizontally, as there is no object in screening the whole of a lofty roof. Curtains are suspended along these pairs of wires by means of curtain hooks, firmly stitched at intervals along each of the long sides of the material, and then hooked to rings, placed beforehand, on the wires. At first I used to attach the rings direct to the curtains, and thread them on to the wire, but, when they had to be taken down for repair or during decoration, the labour of re-erecting was greater than any one could imagine who had no experience with them. It should be understood that each length of curtain is divided into three separate independent pieces, ao that tlie light can be brought almost anywhere, as a broad or narrow pencil, this being also facilitated by allowing plenty of length in each curtain, so that their combined length, if stretched to their fullest, would be much more than the lengths of the wires they are suspended from. Liyhter serpens will also be needed for softening and subduin-j- the light, or for killing the direct rays of the sun when early or late they cross the iield of view. I have tried almost everything, but have de- rived the greatest comfort from the material called "tracing cloth." It is close-grained, robs the liglit very little, and can be kept quite clean by a simple duster. The kind glazed on both sides should be asked for, and I can promise those unfamiliar with the fabric whd care to try it that they will be very pleased with its performance. It is infinitely preferable to the more common plan of whitening the glass during summer-time when the light is strong, for it robs the light of less of its actinic effect, and can be instantly brought into play or folded out of sight according to the exigencies of light. These blinds with me are attached to rollers, and work from the ridge downwards almost close to the glass. To avoid swagging thev are each supported by three wires stretched in the direction of thei length from ridge to eaves. 1 now take leave of my readers, trusting that what I have writtd^ may be of benefit to some. I shall be pleased if any one who wishes for further -information would ask me, through the columns of the .louHNAL anything that may tend to further elucidation of what may be insufficiently described in my remarks. G. Watmough Webstbb, F.C.S. AMERICAN NOTES AND NEWS. A Dark Room for Chicagro The Cramer Dry Plate Compan}- are enterprising. They have secured the sole right to erect a dark room on the World's Fair grounds in which photographers may change their plates, and they probably have had to pay a large sura for the concession. This, however, is not all ; the dark room is to be under the charge of a competent attendant, and this spirited Company are to make no charge to the visitors who choose to avail themselves of its shelter for changing their plates. This is a good stroke of policy, as it is certain to be appreciated, and will eventually richly repay Mr. Cramer and his colleagues. This generosity deserves to be noted. An American visitor to this couutry not many months ago complained to us that he had been charged seven shillings and sixpence by a dealer in one of the main streets of London for the use of a dark room in which to change his plates, these pl.iles havihgbeen supplied from the same establishment. We could only reply that the principal of the business was doubtless ignorant of this act, as it was S74 THE BKlTISn JOURNAL OF rHOTOGRAPUV, [June 16, 1893 evidently so contrary to his interests to amerce a customer in such a charge. The money demanded was paid, but aU dealings there terminated. Tlie "Beacon's" Non-appreclatlon.— TheP/Wo-iS^'aro.i is somewhat strongly down on Dr. P. H. Emerson on account of the paper he lately contributed to the Photographic Society of Great Britain. Under the heading " Recantation Recanted," it tries to hold the author up to ridicule, characterising the paper as too silly to be laughed at and as the most absurd matter that ever appeared in a photographic jou'-nal. We, on the contrary, think that there is much that is really good in the paper alluded to. An " Infantometer."— Such ii the title given by the fore- going journal to an extract from an article by C W. CanfieM, in the' Photographic Times. This gentleman claims that composite pho- tography was foreshadowed in 18.3?> by Mr. Mascher, of Philadelphia (where so many things in photography have been discovered), whose circular regarding etereoscopii; Daguerreotypes contains the follow- ing:— " I have taken a gentleman's picture on one plate, and a kdy's on the other, and by placing them in the stereoscope they were blended together, producing the most astonishing effect. The result- ing picture is not a true picture of the one or the other, yet possesses the most prominent features of each, making a picture wonderfully like one of their children. From this it is suggested that those true lovers who wish to see what sort of appearance their children, should they be so blessed, will have, have merely to have either a stereo- graph of this nature, or by preference a true composite photograph taken, and by the union of the lady and gentleman will be obtained a likeness of the desired baby — in fact an ' infantometer.' " We ask with Charles Dudley Warner, Who, after this, dare say that Americans are mentally commDaplac3 and unimaginative ? 'What the Button-preasers tose. — The New York Tribune says that the enjoyment derived from pressing the button and hiring soms one else to " do the rest " is of brief duration, and attended with much expense. The feeling of triumphant success which attends the production of a finished and mounted print by one's own hand is wholly lacking, and with this lacking the chief charm of amateur photography is lost, and there is nothing which can take its place. The artistic treatment of an artistic subject affords a field for work into which few may venture and hope for success unless tbev are fully determined to master all the details of the work. This is absolutely true, but it does not apply to any reader of the British Jou't ml of Phot.ograj)hy, as our readers " do the rest " themselves. Indeed, we have a rather firm persuasion that mere button pressors are ignorant of the exiitence of photographic literature. A NEW DEVELOPER FOR GELVTINE DRY PLATES. Abstbact. 1. A DEVELOPER containing a soluble salt of silver incorporated with gelatine and suitable reducm" agents, whereby in the progress of the development the image is built up electrolytically from the silver con- tained in the developer itself. 2. Preventing the veiling of the image, or fog during development, by the addition to the developing solution of an easily reducible compound of silver; permitting the development of under-timed plates to be prolonged at will, until all detail impressed by the action of light upon the film is brought out and the desire! density obtained. 3. A method of intensification before fixing, enabling a negative worked up to the practicable limit of developrnt-nt by any of the formulae in use to be further developed until sufficiently dense. Introduction. Daring the winter of 18)2, an investigation of the chemical action of the different developing agents employed with gelatine dry plates was conducted jointly by Mr. W. Dinwiddle, of the U.S. Geological Survey, and the writer. In the progress of the experimental work it was noted that, while all soluble sglw of a;ver were rapidly reduced and precipitated by the addition of a solution of ferrous sulphate, hydroquinone, or any other developing agent, yet, if the silver salts were tirst emulsified or combined with gelatine, no precipitation occurred even by the prolonged action of concentrated solutions.* Further, that suitable developing agents incorporated with the emul- sified silver salt constituted a developer of unusual power for gelatine dry plates, specially applicable for instantaneous and under-exposures. An application for U.S. patent was made for this discovery, and is now pending. Dkscbiption. The accepted theory of the action of the developer upon gelatine dry plates is, that the latent image formed by the action of light upon the film becomes visible through the reduction of the photo- ■broaiide of silver to dark-coloured reduction compound.-) and finely divided metallic silver by the chemical action of the developing agent, and that ilie image is further strengthened by a weak electro- lytic action induced, whereby the image is built up from the bromide of silver, unaltered by light, remaining in the film. With a developer containing silver, this electrolytic action may be increased and greatly prolonged, the image gaining additional intensity from the silver derived from the developer. The veiling of the image, or fog, produced by excessive strength of the developing agent, or by its prolonged action, is thought to result from a reduction of the unaltered silver bromide disseminated in the film. This fogging may be prevented by the addition to the de- veloper of a small amount — less than a half per cent. — of an easily reducible talt of silver. The silver salt in the developer is more easily reduced by the developing agent than the unaltered silver bromide in the film, and protects the latter from reduction and pre- vents fogging as perfectly as the coating of zinc given to iron in the galvanising process protects the metal from oxidation. This pro- tective action of the silver in the developer is increased by bromide of potassium, which restrains the reduction of the silver bromide by the formation of adiihcultly reducible compound, without interfering with the action of the argentic developer. Resultant from this is the power of prolonging development indefinitely without danger of fogging. Tliis developer may be prepared in two forms, as an emulsion, composed of the double sulphite of silver and soda, combined with gelatine, suitable for incorporation with any of the developers in use, or as a single solution ready for use, containing in proper proportions the argentic emulsion, developing agents, and alkali. In either form it is an opaque olive-coloured emulsion, miscible in all proportions with water. The silver salts employed are the different double sulphites of silver and soda. These enter into combination with gelatine, with the formation of stable compounds, capable of existing in a chemically passive condition in the presence of the strongest reducing or developing agents. It should not be understood that this developer brings out much more detail than can be obtained by the exercise of skill with pyro. What is actually accomplished is a relatively uniform increase in density all over the plate, and a strengtliening of the delicate detail in the low lights and shadows. The ultimat« object of development is not the negative, but a print obtained from it; and, by the employment of argentic emulsions, detail visible only as delicate tracery in the film may be built up in silver until it becomes printable. Measured by practical results, the time of exposure of all well- lighted subjects may be reduced to from one-fifth to one-tenth normal (f-5 to c-10). This is equivalent to an advance of two or three numbers in the seneitometer number of the plates used. With Carbutt's ortho- chromatic plates. Sen. No. 23, well-developed instantaneous views were obtained in bright sunlight with the exposure given by a Prosch shutter and full opening of lens; also in many successful experi- ments where the normal exposure was carefully determined by Watkins' meter; the exposures actually given were in well-lighted views one-tenth normal, increased to e-4 where detail was desired in the shadow,-. Smill diaphragms can be used in instantaneous views in strong light where there are not deep shadows. With quick plates, a lens of ordinary rapidity (f-d=8), and a shutter speed of one-fiftieth or one- hundredth of a second ; a diaphragm of /-IC will afford, by prolonging * This restraining action of jjelatine and other organic substances, such as sugar, starch, glr.eose, and giini arabic, has been remarked by Abney and Carey Lea. The older text-books on photography describe a method of redevelojinient or intensification of collodion wet flatea before ti.\ing, by the addition of silver nitrate to the acetic acid and pyro developer. June 10, 1893] THE BRITISH JOUKNAL OF PHOTUORAPHy. 376 the derclnpment, negatives that almost equal time exposures in detail and duBnition. The opaque doveloper protects the plate from all action by light in tlip dark room. Precaution should be taken that the plates are not in the least lijrht fosged whil-i in the plate holder.", as on development the fog is intensified. Further, by its use, development is reduced to a mechanical process, requiring little attention and easily carried out by any one. The employment of argentic salts in photographic developers is as yet in the experimental stage ; its pos-tible future evolution cannot be predicted. From want of time, the experiments were confined to the development of dry plates ; the action of argentic emulsions upon bromide paper is unknown. Most of the experiments have been made with strongly alkaline eikonogen and bydroquinone developers, a few tests only with pyro, and none with ferrous oxalate or other ferrous developers. The new developing agents requiring but little alkali, such as amidol and metol, offer the greatest encouragement for investigation. Further, this use of silver salts suggests the pos.sible employment of other metallic salts, such as platinum and gold, in photographic developers. In astronomical work argentic developers will probably prove of v.ilue, and in certain photographic processes requiring negatives of extreme density, they mav find » place. The prevailing rule in landscape photography is to somewhat over- expose, depending upon development to correct the consequent tendency to flatness and lack of contrast in the negatives. It is even -itated that there is a greater latitude on the side of over-timing. The experiments made by the writer indicate that below normal exposure the latitude is at least proportionately as great, and that superior negatives result from exposures, which while sufficient to impress upon the film the most delicate detail in the shadows, are yet far under the time thought to be requisite to obtain the best results. Thk Argentic Emulsion. The Preparatiim of Silver Tartrate. — As silver tartrate is rapidly darkened and decomposed by exposure to white light, this emulsion is best prepared in the dark or under a red light. A solution of Nitrate of silver 200 grains, Distilled water (cold) 12 ounce.', is precipitated by the equivalent weight of tartrate of potash ; the amount varies slightly with different samples, but is, approximately, DistUled water (cold) 2 ounces, Tartrate of potash 105 to 120 grains. The bulky white precipitate of silver tartrate is soluble in pure water. It is not washed, but placed upon a filter and allowed to drain. The filtrate contains some silver, which can be precipitated as chloride and recovered. The moist precipitate of silver tartrate is removed from the filter, paper and dissolved with rapid stirring in a warm solution of Sulphite of soda crystals (pure) 8(X) grains. Distilled water (hot) 4 ounces. Glycerine (pure) 1 ounce. If the soda sulphite solution is not distinctly alkaline, it should be made so by the addition of carbonate of potash or soda, twenty to thirty grains, before adding the silver tartrate, to prevent the forma- tion of a precipitate of the difficultly soluble, crystalline double tar- trate of silver and potash, which separates in neutral and acid solutions. The solution of the double sulphite of soda and silver, is nearly colourless and transparent. It is filtered, to remove a slight precipi- tate of silver sulphide derived from the impurities of the chemicals used. A solution is made on a water bath, with care to avoid over-heating and decomposing the gelatine, of — Nelson's sheet gelatine No. 2 100 grains. Distilled water (hot) 2 ounces. Then add— Pure glycerine 2 ounces. It is advisable to soak the gelatine for one hour in one half of the above quantity of cold water; the swelled gelatine quickly dissolves on the addition of the moiety at the boiling temperature. The silver solution is gradually added to the solution of gelatine, with constant stirring to avoid the precipitation of the gelatine ; both solutions should be warm when incorporated (100' to 120" Fahr.). The resulting solution is made up to a volume of twelve ounces by the addition of water. At first it is clear and transparent, but soon chanires to an oli«e-grey opaque emulsion, that on cooling gets to a thick jelly. When required for use, the emulsion is liquefied by immersing tl e bottle containing it in a dish of warm water. It is best kept in the dark, or in a bottle wrapped in opaque paper, (.'ndersuch conditions this emulsion does not appear to undergo decomposition, the glycerini' and sulpiiites of silver and soda acting as preservatives. On heating to a tem|)erature approaching the boiling point of water, decomposi- tion ensues, with precipitation of metallic silver in the golden-yellow allotropic form described by Carey Lea.* Not infrequently the emuLiun is of a beautiful purple shade when viewed by transmitted li<.'ht, indicating the presence of photo-salts of silver. This formula afTords an emulsion in which the silver salt is strongly restrained ; one part of gelatine is combined with two parts of silver salts and eight parts of sulphite of soda. In order to increase the sensitiveness of the silver compound and accelerate the electrolytic action in development, the proportion of the gelatine should be de- creased to possibly two-thirds or even one-half of that above given. A few experiments indicate that the addition of Rochelle salt or a solution of inverted sugar makes the electrolytic action more energetic. It is possible to make the emulsion so sensitive that it will not Keep, readily decomposing, with precipitation of metallic silver, forming during development a mirror of brilliant silver over the whole surface of the negative and the bottom of the developing tray. In place of the tartrate of silver, tlie metabisulphite may be em- ployed ; the solution of nitrate of silver is precipitated by the addition of a weak solution of metabisulphite of soda or potash as long as a precipitate continues to form. The white or pinkish-white, curdy precipitate of silver nietabisulphitef is washed by decantation with cold water and dissolved in a neutral solution of sulphite of soda, forming the double salt, which finally is incorporated with gelatine and glycerine in the above proportions. The grade of photographic gelatine known to the trade as No. 2 appears to be the most suitable. The harder grades of gelatine afford thick and sticky emulsions, while soft gelatines, such as No. 1, have but feeble restraining power. Glycerine, when forming fifteen to twenty-five per cent, of the volume of the emulsion, is an efficient preservative. The addition of glycerine renders the gelatine more tractable in incorporating the concentrated solutions forming the developer. It has but little restraining action when used alone. W. P. Jenney, Ph. D. {To be concluded.) DENSITY RATIOS ASD EXPOSURE. Thb question whether latitude in exposure exists in a sensitive film, and, if so, to what extent, is of such wide importance that Mr. W. K. Burton's letter to Photographic Scraps on this subject is sure to attract much notice. Anything that Mr. Burton writes is sure to bo useful and practical, and with the information given in his article any one can repeat the experiments for himself, and compare the results. There are one or two points, however, to which I should like to draw attention, as either simplifying the work or tending to confuse the issue. In the first place, I should recommend all experiments to be made either with a screen of some sort or by a series of exposures, as indicated in the last paragraph of Mr. Burton's communication. It is quite easy to compare results obtained in this way, i.e., a series of tints increasing in depth in a fixed ratio. It is, however, practically impossible to do more than give an opinion — 'm which the personal equation is liable to be unduly prominent — upon the similarity of two ordinary negatives, neither of which may correctly represent the natural original, and in which there is no certain guide as to true representation ; that is to say, as to how much deposit should represent a certain portion of the view. For like reasons a series of deposits of silver caused by the un- impeded action of light is much to be preferred to the results with a coloured screen, such as Warnerke's. It is more easy to compare the tints, and, in case accurate measurement should afterwards be re- quired, more'useful. An instrument forthe purpose can be made from a half-plate printing frame with the aid of some pieces of cardboard in a * American Journal of .'Science, 1887-89, 3d aer., vols. ixxuL, xxxviii. t Whether this silver salt is a true metabisulphite is some«(hat,uncertaip. It is different ia behaviour in the emulsion from the silver sulphite pitidace'd by precipitating silver nitrate by sodium sulphite. 376 THE BRITISH JOURNAL OF PHOTOGRAPHY. [June 16, 1893 few minute', anil is alwsis handy for comparing one lot of pliites ■with auutlicr. Further than this, in the direction of laboratory test- ing, I do not think it advisable or necessary for the ordinary photo- grapher to go. Photography has been named an art-science, but, as far as negative-making goes, tlie two branches are far apart. The artist cares little as a rule as to the appearance of his negative, or, at all events, if he does care, he is willing to sacrifice the look of the negative to the appearance of the resulting print, if to secure a good (looking) negative means any loss in the picture itself. The aim of photography, tlien, to ninety-nine percent, of its votaiies and admirers IS idctorial, and is an appeal to the senses through the eye. Whilst, therefore, I am altogether an advocate for the laboratory exposure test as against the negative-making test for ascertaining the qualities and rapidity of an emulsion, 1 think that the practical photograph for final judgment of its qualities ought to be formed, not from this test negative plate but from photographic prints produced in exactly the nsual way from those test negatives rather than by measurement of the deposit. And I think this, on the ground which I expect to have my readers' sympathy upon, that every photographer can form his opinion as to the comparative excellence of two or more prints which ostensibly represent a series of gradations from dark to light, each tint increasing in depth in a known and appreciable degree. Moreover, any limitations of the printing process are self-evident and allowed for in the result. It is a pretty generally accepted fact that no printing process can reproduce all the gradation in a fine negative. The scientific measurement is to that extent misleading, and I prefer to compare prints. AVere photography purely a science, I should prefer the use of measurements for general purposes; but, as I esteem it an art, I prefer to abide by the tribunal to which it ultimately appeals, viz., the visual faculties and critical sense. Scientific measurements are of more use to manufacturers than to the picture- maker ; graphic measurements, if I may so christen my method, are principally useful to the worker. With these ideas in my mind, I have gone over the experiments on Mr. Burton's lines as indicated in his letter, and, in order to get a wider trial, I have not limited myself to one make of plate, although there is probabh' little reason why much difference, if any, should be expected on this ground, except it be on the score of difference in the thickness of coating. My trials amply illustrate this point, viz,, that the thicker the coating of emulsion, the more easily is over- exposure tolerated by the plate. Still, different makes of plates do stand, and even demand, very different methods of treatment. Briefly stated, I do not find that I can, with sensitometer tests (in which one knows what relative density to expect), get negatives, to use Mr. Burton's own phrase, givinr/ prints that are' identical. Not only can the negatives be distinguished by the difference in colour of the image, but the prints also are marked by certain characteristic differences which, in my experience, have occurred in a consistent and regular manner. These differences mainly are that the tones of the pictures upon the long-exposed plates are less differentiated than in • the normal exposures, and that the pictures seemed to be pitched in slower key. I have always noticed that photographers who back their plates, give long exposures, and then trust to restrained develop- ment, get pictures of this character. Now, these are very pleasing of their kind, but they are quite different from, and can be easily distinguished from pictures whose original negatives have been made with wiiat is usually called correct exposures. I mention the point, however, as it confirms me in the belief that it is going too far to say, as Mr. Burton writes, that " an experienced plwtographer cannot tell ■which is from the negative that has had the longest exposure, and which from the normal exposure." A good negative can be made from the plate receiving the longer exposure, and by the method he indicates, but it is different in grada- tion m the middle-tones, and with a sensitometer test, such as I mentioned in the eailier part of this article, can be fairly easily recognised. There is one point which I should like to add to these remarks as to Mr. Burton's method of development, viz , that the developer, strong in pyro and bromide, seems to have but little effect upon a plate if tried in error. For example, suppose one is not sure which plate is the over-exposed one. If it be tried in the strong developer and no image appears, the plate can be washed and development recom- Hienced with a normal solution without, I thmk, any perceptible alteration of tone rendering. I have not referred here to the we of the citrates for remedying the effects of over-exposure— although I am inclined to preferthem to Mr. Burton's method — nor which sort of picture, viz., that obtained wkh normal or prolonged exposure, will appeal most strongly to the majority of photographers, but simply to state the opinion that. as critically examined under conditions which admit of it, the grada- tions in the two cases under discussion are dissimilar. A thicker coating of emulsion, and effective backing, both materially assist in reducing this dissimilarity, but do not overcome it. S. Hbbbkht Fby. "IN DARKEST PHOTOGRAPHY— THE WAY OUT." In reference to the great depression now existing in the businesses of professional photographers, and how to remedy such a state of affairs, it would, perhaps, be as well to seek the causes of the disease (which are, doubtless, many) before suggesting a remedy, and which remedy should be as complete as possible, considering the gravity of the complaint. That a large number of workers have joined the ranks of profession- alism since the introduction of gelatine plates is, alas, only too true ; but, are they possessed of the same amount of skill and ability as the old wet plate workers? There can be only one answer to this question. No ! L'nfortunately, No ! Now, there are numbers of men in most of the large provincial towns in the kingdom who trade as so-styled artists and photo- graphers, when they are, in fact, nothing of the kind. They have no studios, are quite incompetent to take a negative, and much less finish a print. Who are these individuals '? Why, simply canvassers, men who have been previously emplo3'ed by some big firm as travellers for club or subscription portraits, and by some little smattering obtained in the course of their business as to certain items in the same, and by forming a tolerably good connexion, and by saving a little money, have been enabled to dissociate themselves from their employers and make a start for themselves as " full-blown " photo- graphers. They enlist the services of some local man (who possib'y might be better employed), and arrange with him " to take '' for them at a certain price per negative, which is to become their sole property. Possessed of this, they send it firstly to some firm of enlargers for an enlargement to be made therefrom, and secondly send that elsewhere to bo finished either in colours or monochrome, according to their in- structions. These gentry can purchase mounts and frames as cheap and as readily as any professional, and thus they daily, weekly, and yearly compete, with no knowledge, or very, very little, of photo- graphic details, against the man who has served a lifetime to the profession, and who, figuratively speaking, "knows more in his little finger than they do in the whole of their bodies.'' Are they photo- graphers ? Have they the slightest pretensions to be styled as such ? Is it not a perfect anomaly ? Is it not • preposterous that they should be allowed to designate themselves as such ? Is it not time that the closure should be adopted towards stopping such a state of affairs? But these are not the only delinquents who cause professional bad trade. There is another and a very big one, and possibly a more difficult problem to deal with, and that is the amateur. We are con- tinually informed that they do no harm to the professional, that the big guns of the profession suffer in no way bv them. But, for all these reiterated statements, it may yet be said they do no good. Many instances might be quoted where they have supplanted the professional and the services of amateurs have been engaged as against the man whose living it is, much to his detriment and financial loss, and it is quite obvious that a man who earns his bread by the pro- fession that he fo\\o\\s should not be ousted by one who only attempts such work as a pastime and amusement, and draws the means of his support from some other source altogether. It .seems somewhat sur- prising (to those especially who can remember a different state of aft'airs to exist) that the photographic press generally should take so much cognisance, and repcjrt the proceedings of amateurs and their societies. If less prominence were given to their sayings and doings, they would most probably return to that obscurity from whence they came. And now as to the cause of the existence of so many amateurs among us at present. The profession has certain members of their own profession to thank for that. What would you think of a photo- grapher (?) proudly boasting of the following — that he had supplied some 200 cheap camera sets, quite promiscuously to any one that chose to buy, and on the further understanding that if they also purchased their plates, chemicals, &c., from him, ^e would give them free instruction, and supposing that the locality was already over- stocked with legitimate workers, here were another 200 let loose to stiU further undermine the interests of the profession and inevitably cause a reduction of prices of work. There is too great a tendency at present among professional photo- graphers, to add the sale of apparatus, chemicals, &c., to the ordinary June 10, 189a] THE BRITISH JOURNAL OJf rilOTOORAI'HY. 877 branches of their businesses. It is ,-castek A- Soss, Biemisgbam. In the opening pages of their Catalogue for 1893, which has just been issued, Messrs. J. Lancaster & Sons, of Colmore-row, Birmingham, point with pardonable pride to the circumstance that, np to date, they have sold 105,000 cameras and 160,000 lenses. This in itself may be accepted not only as an evidence of the prosperity of Messrs. Lancaster s business, but also as some faint indication of the extent of photography itself, which, though it may be a trite enough thing to say, is nevertheless true, that it has grasped the interest and attention of all classes of people to a degree that characterises no other pseudo-scientific recreation. The Catalogue in question includes, in addition to illustrated par- ticulars of the firms' many familiar specialities, several new and novel designs in photogn^hie apparatus for the current season, many of which were shown us on the occasion of a recent visit to Messrs. Lancaster's establishment. First of these may be mentioned the aluminium- mounted Instantograph, a camera which, by reason of the substitution of aluminium mountings for brass, is ideally light. The camera, which is made out of selected mahogany, of the smallest possible size, with a due regard to strength, has aluminium binding, aluminium front stage, plates, screws, Ac, as well as double swing back, long extension, reversing back, and all recent improvements. The lens is mounted in aluminium, and has the firm's patent aluminium see-saw shutter. The stand has an aluminium top. This stand top is an especially well-finished piece of work. Regarding the working of aluminium, Mr. Lancaster informs us that, in experi- menting with it as a substitute for brass, considerable time and money have been expended. The 1893 special brass-bound Instantograph is a handsome camera of the best finish, designed to meet a general wish for a high-class brass- bound camera having all necessary movements. The 1893 Portable Instantograph is a new hand and stand camera, with which a light stand is supplied for the latter purpose. It will be observed that, folded up, it presents an appearance as unlike a camera as it well could be, thus im- parting to it a character which may easily elude theobservation. Messrs. Lancaster are taking advantage of this happy idea to impart a"detective-camera"-like appearance to their "Ladies' Camera," a camera with but few movements, and therefore eminently suitable to the fair sex. This camera, when folded up and carried in the hand of a lady, looks not unlike a reticule or some similar receptacle which ladies are in the habit of carrying. Among the other varieties of Messrs. Lancaster's cameras which may be mentioned are the 1893 Pocket Instantograph, which is extremely light and portable, has alnminium binding, runners, front stage, dc. and which, with the lens, shutter, and double slides, are packed and carried in a very small leather case. The principal feature of the Extra Special camera is that it has a triple extension, thus enabUng one to obtain a very great length of focus. In reference to the use of alu- minium, Mr. Lancaster showed us samples of the metal, which, for experimental purposes, had been gilded, to give it the appearance somewhat of brass. The Recto- graph series of lenses are now alu- minium-mounted if desired, and are also supplied in cases similar to those in which jewels are placed, thus giving them a highly chast and taking appearance. Among the firm's sets, that for boys at a guinea, which includes every thin necessary to enable a lad to make his first experiments in photo- graphy, is a marvel of cheapness and completeness. Hand cameras also receive the firm's attention, Omnigraph being their latest pattern. the Wy.i Perfect Among its other features, it has horizontal and vertical finders in the same plane as 1*ie lens, registered adjustment for any focus, which is obtained June 10, isna] THE BRITISH JOURNAL OF PIlOTOORAPIl V. 379 by mOTing the lens. It is fitted, at the pleasure of the purchaser, with cither molal elides or a special chacging bos. The slides, which are shown in the cuts, arc made of light metal, and the top of the frame is hinged, so that the plates can be removed without the least danger of asratching or rubbing. The woodcut on the left show^ the slide closed, and that on the right side shows the frame open to receive plates. The plates are placed back to bock in the grooves, with a sheet of opaque material between them. The changing boxes are fitted with raotal carriers, each carrier being con- tructcd to hold two plates, with a division between them ; the frame is then closed and fastened by means of a sliding pin. The three carriers are then put into the changing box. Tluroughout the extensive range of the firm's specialities, a vast deal of ingenuity is involved, all classes of photographers being' catered for, so that it is not surprising that Messrs. Lancaster's weekly output runs to an average of 400 cameras. ATEiNBOii'a Nzw Backorouxds. Mr. J. J. Atkinson, of Manchester-street, Liverpool, showed us some new series of backgrounds which should be welcome to professional photo- graphers on the look-out for novelty and variety in this direction. One of these, the " Children's" series, which are produced by Seavey, of New York, represents a number of artistically painted scenes, interior and ex- terior, which are calculated to suit youthful sitters. The backgrounds are made in the usual sizes, and the subjects are so much out of the common, both in selection and style of treatment, that they are certain to be popular with our professional friends. Seavey's skill is also well exemplified in the Columbian series for adults, curtained windows, divans, artistic furniture, *g., being made to do duty with uniform success. A third series is that of Bryant (for whom Messrs. E. & H. T. Anthony, of New York, aie the agents, but which are also in the hands of Mr. Atkinson, for this country). These represent a number of charming landscapes, unconventional and delicate in treatment. A wider adoption of natural and truthful backgrounds, such as those of Mr. Atkinson, should prove a great service to many photographers in im- proving the quality of their work and increasing their business. The "All-in-One" rLAlEw.isHiNo Backs, Mr. W. Tylar, of High-street, Aston, Birmingham, is introducing a new form of adjustable platewasher under the above title. Its principal feature is that it takes any size up to whole-plate, either eighteen 3J x 3|, 4| X 3^, 5x4, stereo- scopic, half-plate, 7J x 5, or nine whole-plates, being inserted at one time in the grooves, or / B^^^^5^*^ir~~~— ^ fliP^Sifflit "^'"^ whole-plates ; or, for mixed sizes, nine each of cither 3J x 3^ or quarter plate, 5x4 or 7Ax5, &c. It is made of zinc, and packs up into a small compass. In use, the arms carrying the grooves are fixed at different distances on the sides of the rack, which is rendered rigid by ccrews at each end. The " AU-in- One " should prove very convenient where a number ol different platea are desired to be washed at one and the same time. Messrs. Jas. Woolley, Sons, * Co., of Manchester, who occupy Urge and handsome premises in that town which are devoted to the distribution among chemists, doctors, d-c, of drugs, chemical and scientific apparatus, &c., also include among their numerous department! one set aside for photography, which is filled with an extensive and assorted stock of all photographic requisites. Among the recent novelties embraced in their catalogue is the "Sandell" fixing tank, which has been introduced to meet the requirements of the Sandell plate. It has a light and dust- proof cover, and a strong rack, which can be suspended from the top. The plates are placed vertically in the tank, and for draining purposes are held in the rack at the top of it. Calling in upon Mr. J. T. Chapman, of Albert-sqnare, Manchester, when in that town, we were pleased to hear from him that he was ex- tremely busy in photographic apparatus and materials, Ac, a fact of which we had ocular evidence. Indeed, photography generally, or rather that branch of it which concerns itself with the supply of materials, especially to amateur workers, seems m the north of England to be in a very healthy condition — a state of things, no doubt, in some measore due to the recent fine weather. I » ®ur lEtiitorial ^atU. Amatbue Photogkai'hehs' Annual fob 1893. Londou : Hazell, Watson, & Viney. This Annual is illustrated by no fewer than fourteen pictures, and several articles, mainly of a practical nature. These are headed by the editor, who leads off with a good article on the carbon process, in the course of which be tells us as succinctly as possible all that is known concerning it. He is followed by Mr. A. Horsley Hinton, who treats on subjects connected with pictorial composition, and the trimming of priuts. The other articles are "Practical Work," by John A. Hodges {the leading one in the volume), and "Protecting Inventions," bv Naunton. Then follow, arranged in dictionary fashion, a holiday guide, in which, like the ABC Jiailway Guide, the population of numerous places, their distance from London, and other useful in- formation are given. The Annual is well got up and will prove useful for reference. J. Lancaster & Sons' Xew Catalogue. As far as catalogues go, this one for 1893 is a work of art. It con- tains four pictures, taken, as may be well understood, with Messrs. Lancaster's apparatus, besides numerous cuts illustrative of cameras, lenses, stands, lamps, and every other thing required in photography. Lancaster's Catalogue, unlike others, is condned to objects of their own manufacture, and they are very numerous and varied. They fill eighty pages. The Catalogue, which sells at Ad., is a model of excellence. Mills' Mountant. Ma. G. W. Mills, Highgate, sends us a sample of a mountant he prepares for enamelled and similar prints in which the gloss is desired to be maintained. Its basis seems to be dextrine, to judge from the smell. The directions for use are to apply it to the back of the print wi'ti a stiff brush and then rub well in contact with the mount. It w V answer its intended purpose well. Flashlight PoninAiTS. By W. E. Debexham, 46, Haverrtock-hiU, N.W. Ma. Df.benham has submitted to us for inspection a series of portraits taken on the occasion of a fancy-dress ball by means of a Hashligbt. Excepting, perhaps, the presence of the cast shadows, it would be difficult to discover that these portraits were not studio work naturally lighted, the absence of harshness of lighting usually seen in such results being very noticeable. There is a roundness of feature combined with softness of texture which speak well for the management of the light and the accuracy of exposure. As ex- amples of this kind of portraiture, Mr. Debenham's results are very successful. 380 THE BRITISH JOURNAL OF PHOTOGRAPHY. [June 16, 1893 New Shuiteb for Stkkboscopic Photography. >Ib. J. R. GoTZ, 19, Buckingham-street, W.C, has brought out a new form of shutter— the Ariel— -which is simplicity itself, or, as Mr. Gotz expresses it, the redtictio ad absurdum of shutter action. The cut shows its external form. Pressure upon a pneumatic ball drives up a box piston which loosely fits the cylinder, and this, in risino-, enfrages with a double lever by which the shutter blades are opened and closed, either instantaneously or are amenable to time exposure. The blades are cut square, so as to give a square aperture. This shutter is so convenient, and of such pocketable dimensions, as to ensure a large demand for it. * The Ilforu Exposure Meter and How to Usb it. Those who possess an Almanac for the present year are doubtless familiar with Mr. John Howson's article on "The Ilford Exposure Meter," which had not at the time of issuing this Annual been quite ready. A specimen is now before us, and is illustrated by the adjoining cut. The Meter, which has been invented by Professor J. A. Scott, of Dublin , in order to f urn ish a convenient method for performing the various calculations necessary in estimating photographic exposures in a purely mechanical manner, consists of three movable circles or discs, which revolve freely on a central axis, to which are fixed two circular plates, one forming the centre of the front, and the other the back of the instrument. These discs respectively are : " Plate Circle," " Date Circle," "Diaphragm Circle," and "Subject Circle." On the outside is the " Exposure Circle." These are all movable, except the first and the last. The Meter is elegantly made in ebonite, and can be carried in the pocket without the slightest in- convenience, being only three inches in diameter and weighing one ounce. From the well-known reliability of everything that emanates from the Ilford Company, it is almost superfluous to say that this useful exposure meter can be quite depended upon. Wo endorse the statement on the front of the pamphlet of instructions, that it is a common-sense and certain means of gauging exposures. RECENT PATENTS. APPLICATIONS FOR PATENTS. No. 10,971.— "An Improved Construction of Frame for Photographs and other Pictures and Designs." L. Wakk.— /)aferf June a, 1893. No. 11,179.— "Improvements in Magazine Cameras." S. D. Williams- Jtated June 7, 1893. No. 11,210. — "Improvements in Photographic Cameras." S H Brtttain and G. D. Hughes. —i>a(e(i June 8, 1193. No. 11,212.— "Improvements iu Photographic Camera.'." .J F P\nsovs Dated June S,l%9Z. . r. i-.Mi.-,oN.s. No. 11, .303. — "Improvements in the Construction of Pliotogr.iphic and other FoMing Tripod Stands." Complete specification. H. J Spkmt A S SfKATl, and G. A. Si'RATT.—Z)rt.— " Improvements in Photograph .and other like Frames " Com- imnicati'd by S. PoseD. A. Qmis.—Dated June 9, 1893. PATENTS COMPLETED. I.MrnovKMENTS IN Photographic Objectives. No. 4377. Albert Barbioi Paevin, 3213 Powelton-aveuue, Philadelphia. , May 13, 1893. My invention has relation to photographic objectives which are adapted to- magnify the image of .in object or objects at great distance, range, length, or position from the camera, .and -with cliaracteristic sharpness in detail. It is generally understood by those skilled in pliotogi-aphy that tlie size of the image of an object upon the ground glass of a camera depends upon one of three conditions: first, the focal length of the objective; second, the distance of the same from the object to be photographed ; and, third, upon, the size of the ovigin.il. Two of these conditions, under certain circumstances, are subject to variation, that is, tlie distance from the object and the focus- of the lens. Of course, if the object to be photographed can be approached, or lenses of different focal powex are at hand, then an image of the required size can be obtained, but such favourable conditions do not e.\ist in everyday practice of the photographer. Tlie required approach to the desired object is often impossible or impracticable, because the required distance is too great to afford re oguisable detail in the resultant negtvtive, requiring lenses of extreme long focus, which necessarily .are rather circumscribed. Suppose, for instance, a photograph is required of an inscription upon a rock alioiit 300 feet high, to obtain a fair view withoiit distortion the operative woulil liave to locate about 700 feet from the rock, and this would liriugtlie inscription about 800 feet in a direct line from the lens. To .secure distinctness or sliarpness as to detail, the letters of the inscription would liave to appear at least four inches higli on the object in the resultant picture. To attain such a result, say, with a lens of 5x6 deters focus, would require a camera witli about an eighteen feet extensiou. Then, again, small images witli subsequent enlargciiient suffer from the disadvantage of the grain of the plate, for even by slight enlargement such is apt to become so objectionably prominent as tO' destroy all detail. The efl'orts to overcome sucli difliculty in exposure' has suggested the use of a tele; cope as a substitute for a photograpliic objective ; but such in practice was found to be awkward and unstable, and, moreover, witli tlie use of tlie firmest tripod, tlie slightest breath of air or the least tremor was calculated to spoil the image of the object. The principal objects of my invention are, first, to overcome the above- mentioned disadviintages and objectionable features, and to provide a photo- graphic objective of comparatively simple construction and effective action for enlarging the imago of an object or objects at equal or unequal disiances from each other with respect to the jiosition of the camera ; second, to provide a photogra)ihic objective having a non-extensible tube provided with a single negative lens ground a.cording to a inatbematical formula to certain radii, to a compound positive lens ground according to a mathematical formula to difl'erent radii, and the construction and arrangement being such that the image of an object or objects at distant points or positions from each other are appreciably enlarged or magnified with marked sharpness of detail in the resultant ueg.itive or sensitive film or plate ; third, to provide a photographic objective with a non-extensible lens tube, having a slit formed in the wall tliereof for the reception of a perforated slide or diaphragm for correcting marginal rays- and with compound convergent positive lens and a divergent neg.itive lens ; fourth, to provide a photographic objective with a non-extensible tube, having a convergent compound lens and a divergent single lens, respectively ground to- different radii, and the length of the lens tulje being proportioned to the- diameters of the lenses, whereby increased magnification and sharpness of detail of the image of the distant object with respect to its real location auA position are obtained ; fifth, to^provide a photographic objective with a tube having ,". double front lens of c^ertain radii, and a single back lens of different radii ; sixth, to provide -i photographic objective with a single divergent lens- having each face or surface thereof of difi'erent radii ; seventh, to provide a photo- graphic objective with a convergent positive lens, and with a negative divergent lens having different radii in respect to the sides or surfaces thereof; eighth, to- provide a lens tube having two lenses, the radii of each of which have a fixed relation with respect to the length of the tube ; ninth, to provide a photo- graphic objective having a nou-e;(teusible tube, with a concavo-convex lens of certain radii of inside curves, and of certain radii of outside curves, to afford certain focal length, and a convexo-concave lens of certain radii adajited to enlarge and to define with decided sharpness of detail the image of a distant object transferred to a film or plate ; and, tenth, to provide a photographic objective adapted to an ordinary camera, and comprising a non-extensible tube, provided with a convergent compound or double lens and a divergent single lens, and the radii of said lenses with resjiect to each other being different ou the respective faces or surfaces thereof, in order to give, by the combination, greatly increaseness as to detail, and with reuiarkable clearness or distinctiveness of field. .My invention furtlur consists of a photoji^aphic objective provided with a non-extensible tube liaving eonvergentanddivergent lenses of certain or defined railii with respect to each other and the length of the tube, and susceptible of being increased or decreased in len^h proportionately as the diameters of the espective lenses are increased or diminished ; and My invention further consists of the iniprovenients in photographic objectives hereinafter described and clain;ed. The nature and general characteristii' features of my invention will be more fully understood from the following description taken in connexion with the ecompanyiug drawings forming part thereof, ami in which llie figure is a longitudinal central section throngli the photographic objec- tive, showing a non-extensible tube provided with a jective, comprising a non-extensible tube, provided with a detachable perforated slide or diaphragm, a compound convergent front lens, and a single divergent rear lens, of different radii in respect to the faces or surface-s, and of ilill'erent focal length, whereby great magnification or enlarge- ment of the im.ige of a distant object ig ensured with characteristic sharpness of detail, substantially as described. .5. A photographic objective provided with a divergent rear lens having faces or surfaces of difierent radii, substan- tially as and for the purposes described. 6. A photographic objective, com- prising a non-extensible tube, provided with a detachable perforated slide or diaphragm, a single convexo-concave rear lens of certain radii as to inside and outside faces or surfaces, and a compound front lens of certain radii as to inside and outside faces or surfaces, substantially as and for the purposes described. 7. A photographic objective, comprising a non-extensible tube, provided with a compound front convergent lens and a single divergent lens respectively, of different focal length, substantially as and for the purposes described. 8. A photographic objective, comprising a non-extensible tube, with a detachable perforated diaphragm, a compound front lens, and a periscopic rear lens, substantially as and for the purposes described. 9. A photographic objective, comprising a non-extensible tube, provided with a compound front lens of certain radii, and a single rear lens of certain radii, substantially as and for the purposes described. 10. A photographic objective, comprising a non- extensible tube, provided with a compound concavo-convex convergent front lens and a single convexo-concave divergent rear lens, substantially as and for the purposes described. 11. A photographic objective, comprising a non- extensible tube, having a compound front convexo-concave lens and a single periscopic rear leas, tne airan-ement being such that great depth of focus is obtained, and the transfer of the image of distant objects embraced within the field to a sensitised film or plate is ensured with great maguiftcation and witiv characteristic sharp'iess of detail, sii'^staiitially as described. JfleetmgjS of SoctetieiS* » MEETINGS OP POCTP!TISS FOR NEXT WEEK. Date of Meelinp. PlAce o Heeting. June AsBo. studio, Nethergate, Dundee. Fillebrook Lecture Hall. Mechanics' Institute, Leeds. Dundee Amateur Fillebrook Atbeufeum Hastings and St. Leonards , Leeds Photo. Society , ^ Kichmond Greyhouml Hoteir i? South Loncion : Hanover Hall. Hanover.park. S.E. S" Birmmjrham Photo. Societj ...^ Club Room, Colonnade HoteL SX , Bnxtou and Clapham : 376, Coldharbour-lane, Brixton. * Hackney.. | 206, Mare-street, Hackney. SX rjorth London Canonburv Tower, Islington, N. ,X I S'"^i°y. I 9, Gauze-street, Paisley. ;J , Koohester Mathfiuatical School, Rochester. ,} I ""'■y Club Booms, 13, A 90°. Series IV. is intended for reproduction work. The paper concluded with a reference to some comparative trials of the lens against other lenses. A large number of prints in illustration of its capabilities were piissed round. Mr. W. a Dkbexham complimented Dr. Goerz on the fairness of his reference to the work of otht-r opticians, and said that, by the specimens bhown, the lens appeared to him to lie a great additional jiower in the hands of photographers, especially as it enabled them to work over a flat field without introducing small apertures. Mr. Dallmeyer said that, by following up what had already been done in the double form of producing a system free from astigmatism, and by using triple combinations, Dr. Goerz had arrived at a larger aperture with flatness of field and greater rapidity than hitherto. He (Mr. Dallmeyer) had not been able to obtain an intensity ratio of more than 1 : 10 with three samples of Chance's glass, similar to that employed by Dr. Goerz. Mr. Warnerke saw Dr. Goerz's lens last February, and then suggested to him to bring it before the Society. The anastigmatic properties of the lens seemed to him better evidenced in the diagrams shown than on the ground glass, and he therefore suggested that the Kew, or optical, method of testing lenses required supplementing by the camera test. Mr. Goerz expressed his willingness to allow the lens to be tested against English lenses. The English makers' lenses would not be too much behind, but they would be a little. The President, in proposing a vote of thanks to Dr. Goerz, which was cordially given, spoke of the excellent nature of the pictures given by the lens. He combated the remark of Mr. Warnerke that the Kew method of testing lenses should be supplemented with photographic tests, saying that just as good results could be obtained by optical means. LONDON AND PROVINCIAL PHOTOGRAPHIC ASSOCIATION. June 8, — Mr. Alexander Mackie in the chair. Mr. S. U. Fry called attention to a letter in a photographic journal referring to some remarks of Mr. Everitt at a previous meeting on the Saudell plates as to range of gradation. Mr. P. Everitt said the complete rendering of such gradation was not possible. Tae scale on a plate, say, one to fifty, would be one to twenty on paper ; tnerefore the paper renders the range imperfectly. Mr. Debenham thought the terms gradation and density were not clearly expressed. Ordinary and Sandell plates differed in respect of density. Mr. A. Cowan did not see why if one plate gave density another plate should not. Mr. J. S. Teape quoted his experience as to the printability of dense parts of plates on paper, but could get a much better gradation on positive plates. Mr. Fry, in reference to the Sandell plates, claimed that they in themselves were an advance, and that their gradation was an inducement to find a printing process better than that which now exists. Mr. R. Child Bayley considered that, in development, it was possible to have in view the after-process of printing, but this was thought to be a reversal of the order of things. A discussion arose on Mr. W. K. Burton's paper in Photographic Scraps. Mr. Cowan promised to make some experiments with reference to what he said on the latitude of exposure, and bring results up at the next meeting. MANCHESTER PHOTOGRAPHIC SOCIETY. JUNE 8,— Mr. Abel Heywood, jun. (President), in the chair. After the election as a member of Mr. F. W. Masters, Mr. J. Wood opened a discussion on Development, which, in a manner, is a subject that has been pretty well thrashed out time after time ; but for all that there is always something to be learnt from the comparison of methods and results. In spite of the many new agents, ammonia and pyro, from the tone of the discussion, are not yet displaced amongst the Manchester members. The President gave the results of some experiments in the intensification of ]ilatinum prints. He said that; seeing an article in the Journal on the sub- ject tempted him to give the method a trial, and he considered the result he obtained on some under-developed prints showed that a flat picture could be improved to some extent The principle was much after the manner of the silver intensification of a wet plate. Mr. Wrigley gave a report of the first outdoor meeting at Smithell's Hall, which had been well attended and successful as regards photography. He exhibited results of his own work, which were in everj- way excefient. Other me nbers also showed iirofitable results from the outing. THE AFFILIATION OF PHOTOGRAPHIC SOCIETIES. June 6, — Meeting of Delegates, at 50, Great Russell-street, Bloomsbury, Mr. Andrew Pringle (Photographic Society of Great Britain and West Kent Amateur Photographic Society), Chairman, presiding. The minutes having been read and confirmed, a balance-sheet up to April 30, showing a balance in hand of 27/. Is. \0d. , was read by the Secretary, and adopted. It was proposed by Mr. Beckerton (Richmond Camera Club), seconded by Mr. Criswick (Greenwich Photographic Association), and oarried, that a balance- sheet should be prepared by the Treasurer up to December 31 in each year, and, having been audited by two auditors appointed at the first meeting of delegates in the same year, shall be presented at the first meeting in the en- suing year. Messrs. Hodsoll (North Kent Amateur Photographic Society) and Beckett (Hackney Photographic Association) were appointed auditors for the current year. It was proposed by Mr. Marchant (North Middlesex Photographic Society), seconded by Mr. Bickerton, and carried, that Mr. Scaniell be asked to continue to act as I'reaaurer. A discussion took place upon the question of approaching the railway com- panies with a view t» the reduction of fares to photographers. A letter from the Birmingham Photographic Society having been read upon the subject. Mr. HoRTON (Birmingham Photographic Society) detailed the steps already taken by his Society in the matter. The Secretary announced that the ajgri'gite number of members repre- ' sented by the Alliliation was, roughly, oOOO. June 10,1893] THE BRITISH JOURNAL OF PHOTOGRAPHY. 363 A Committee, to consiRt of Messrs. Mackie (Photographic Society of (treat Britain) ami Oakilen (South Lomlon rhotogrH]>hic Society), ami the Secretary, was appointed to investigate the whole question of reduced railway fares to photographers, to rejwrt at the next meeting. A letter from the Hon. Secretary of tlie Phototographic Society of Great Britain was read, annoumnng that that Society was arranging for a Congress, and asking for the consent of the Committee for the words " of Alliliated Societies" to be added to the title, "The Congress of the Photographic Society of (ireat Britain," which was agreed to. The letter also asked the delegates to mvite suitable members of their Sot^eties to furnish papers for the Congress. The Chair.man announced that the jiapers already i>romised were from men of the very highest stanportunities of meeting for the discussion of matters of mutual interest ; (3> Where manufacturers and dealers can meet their agents, customers, and friends. Besides these points, the usual attention will Ije paid to the holding of regular weekly meetings, for the discussion of photographic matters, demon- strations, lantern nights, and the exhibition of photographic novelties in apparatus and inventions. "The promises of support in the way of intending members of the Club are most satisfactory, and fully justify the promoters of the Club in saying that, if the capital necessary to suitably equip and furnish the Club premises is forth- coming, the Club will be a success, both financially and socially. After the premises have been acquired and fitted up by the Company, they will be sub-let to the Club at a rental which, it is anticipated, will be sufficient to pay a dividend of five per cent, on the subscribed capital, and to provide a sinking fund for the sustentation of the premises, and the renewal of the furnishings, &c., and the expenses of carrying ou the Company. Before going to additional expense in the formation of the Company, and the further promotion of the Club, the promoters feel that it is necessary to ascer- tain how far they may hope to be supported by the jihotogTaphic public in the matter of capital, and with this object you are invited to fill up and return, -at the earliest possible moment, the enclosed form, specifying how many shares you will be willing to take in the proposed Company. The liability of the shareholders will be limited to the amount of their shares, and no promotion money has been or will be paid, and, in the event of the non-formation of the Company, the provisional committee will bear all the expenses incurred. Promises to take shares have already been received from Miss C. W. Barnes, Mrs. Welt'oicl, Messrs. Birt Acres, R. Beckett, T. Bedding. Frank Bishop, A. Cowan, Austin Edwards, B. J. Eilwards, Thomas Fall, W. Fenton-Jones, J. T. French, T. E. Freshwater, J. 0. Grant, John Howson, J. Martin, George Mason, T. J. Powell, John Reynolds, J. T. Sandell, Woodham Smith, J. S. Teape, E. J. Wall, H. Snowden Ward, W. D. Welford, W. Wentworth, E. A. Whitby, Britannia Works Company, and Percy Lund & Co. Your particular attention is directed to the fact that, unless a sufficient number of shares in the Company is subscribed for and taken up by those interested in the matter, the Club, which promises to be of such great value to the photographic world, and to which so many promises of membership have been already received, will not be brought to a successful issue. You are earnestly requested, therefore, to give the matter your careful consideration, and to return the enclosed form, filled up, on or before the 24th instant. Date 1893. In the event of a Limited Liahilily Company beini; rormed on the lines mentioned in the Provisimial Prospectus of tlie Central Photographic Club, Limited, of the Xdth day of June, 1893. with such variations as circum*tanccs may render necessary, I mill subscribe for and take up shares in such Company, to a nominal value of not exceediny £ as ami when I shall be required so to do. Name Address To Mb. C. H. Oakdex, 51 East Dulwich, Melbourne-grove, S.E. HALATION. To the Editor. Sir, — I notice a letter from Mr. Stringer in the "Correspondence' column of your last issue respecting halation, in which he disputes the tendency of very rapid plates to this fault. I spoke from my own ex- perience as to the effect of rapid and slower plates for the difficult class of subjects alluded to, and have invariably found the slower plates give the best results. The reason is sufficiently simple. All emulsione, and I have made many, when examined by the transmitted light of a gas flame, are, at the outset, orange. As the emulsifying progresses, this orange colour gradually disappears, and gives place to blue or grey ; at the same time the emulsion becomes more and more rapid to a certain 884 THE BRITISH JOURNAL OF PHOTOGRAPHY. [June 16, 1893 point, the particles of bromide having become, from a very fine closely compacted condition, in which they were when the emulsion transmitted orange light, more loosely aggregated and larger— that is, the silver salt becomes coarser when high sensitiveness is obtained, and in a much less resistent state with regard to the lateral dispersion of actinic light, than before. If we could get the orange or fine state of division, at the same time exalted sensitiveness, there is no doubt I should have reason to alter my opinion, but at present this desirable combination has not, I am aware of, been found. It iodide exists in any considerable quantity m a film, it will impart a creamy yellowness when examined by daylight, different to when it is only in minute quantities or absent, and this larger quantity of iodide I prefer for the work alluded to. Mr. Stringer may produce the best results— that is, negatives entirely free from hala- tion—on the very rapid plates ; I cannot, and I do not think myself singular in this experience.— I am, yours, dc, Ehward Duxmore. THE LIGHTING OF GBOUPS. To the Editor. SiR,_You would add to the interest of your " Groups " article if you would tell me how to avoid the heavy shadows and strong lights I get in outdoor work, as per the enclosed example. — Yours, Ac, YouNO Amateur. [See Leader.— Ed.] a,n0toer0 to (Horrcspontienta. J. Milne (Aberdeen). — Eeceived. Thanks. Lens.— A lens of the Euryscope type i.s commonly employed for studio groups. B. Mitchell. — The best and safest hypo eliminator from prints is water, frequently changed. Nothing is better. "VV. BlEUELi.. — We fear we cannot assist you in the matter. Write to the gentlemen named who may be able to advise. K. S. Beowx. — You .are wrong in your surmise as to the plates having been tampered with in the manner suggested. Some other hypothesis will have to be adopted. ■ r. F. W. — We cannot say the actual pressure in pounds or hundredweights that a print is subjected to in burnishing. Of course, that would all depend upon the adjustment of the regulating screw. T. 0. Fox. — In all probability the lantern you saw in the demonstrations at the Society of Arts last year was illuminated by the electric light. The arc light is, we believe, solely employed in the Society's lantern. SlXED.' — We can give no definite clue to the yellow spots. They may have arisen from particles of hypo in the air that have settled on them in course of preparation, but this is merely a surmise. We do not think the mounts are in fault. K. T. A. — Unless you hsive some chemical knowledge, and we gather from your letter that you have uot, we fear the results arrived at will not be very con- clusive. Y'ou cannot do better than get the works named : Fresenius' Analysis: Qualitative and Quantitative^ 2 vols. A. T. — English plates may be obtained at most of the principal towns on the Continent, but there is, of course, the possibility that they may have been a long time in stock. The only way of avoiding the chance of getting stale plates is to procure them direct from the makers and taking them with you. ■Couktrymax. — You will not be allowed to photograph any of the objects of the British Museum unless permission is first obtained, even with a hand camera surreptitiously, for, unless we are mistaken, parcels are not allowed to be earned about the buililing. There will be no difficulty in obtaining the necessary permission if you write to the Trustees stating your object. T. W. — Although the engraving is your own property, and you liave paid a high price for a proof jirint, it will be illegal to co]iy it, even as a lantern slide, without the sanction of the owners of the copyright, and that, we know, they will give. It is true the print is yours, as you have purchased it ; but possessing the print does not entitle you to infringe the cojiyright in it Alf. Benyox says he recently bought a portrait lens, bearing the name of a well-known maker, through an advertisement, but cannot obtain a sharp image with it. On taking it to pieces, he iinds that the back lena is a single piece of glass, a concavo-convex, and asks if the back should not be made up of two lenses ?— Yes certainly. One of the glasses is missing. The front combination may, however, be used as a single lens for such purposes as it may serve ; but as a portrait lens the instrument, as it is, is worthless. Me. W. a. Bezant writes: "Can you give me any information as to the possibilities of photography— that is to say, of obtaining pictures during a trip to Norway on one of the yachting steamers so much advertised? Of course, some work could be done on land ; but what I want to know more jiarticularly is whether much good could be done from the deck of the vessel with a stand camera, and if the light is good enough to permit of shutter exposures with, say, a Koss rapid rectilinear at ,/'-16 or /-2'2, or would you recoujmend me to trust to a hand camera ? " — Doubtless many of our friends who have photographed in Norway will be glad to give Mr. Bezant the information he requires. S. A. H.— The studio shown in sketch No. 3 will be by far the best for general all-round work. No. 1 is very good in skilful hands, but is seldom used now. With regard to No. 2, it has only been put forth as a suggestion, and is scarcely likely to be adopted— at least by professional photographers. T. Evans writes : " I wanted a dead-black vaniish for the inside of some lens mounts, and mixed some lamp-black with thinned white-lard varnish. The black was dead enough when dry, but the surface was quite rough and covered with small lumps. I cleaned this off and mixed some lamp-black with black varnish, and this also behaved the same. Why is this ;"— The reason is that the black was not intimately incorporivted with the varnish. Had it been ground up in a mortar with the varnish there would have been no iiuevenness. 0. Z. says : " The solar camera I am told can be used, and is used abroad, for- making enlargements from small negatives direct on albumenised paper. If that is so, surely direct enlargements in carbon can also be made, as the sensitiveness is about the same, and thus avoid the trouble and cost ot having to make first a transparency, then an enlarged negative to print from. Has the thing ever been tried, or is my idea original ? It must certainly be practicable."— Well, the idea is not original, as enlargements are being pro duced daily by this means in some countries. As however the solar camera cannot he worked when the sun is not shining, the system is practically use- less in this country. RECEn-ED. — H. L. Morel, John Rowden, M. H. Mh. J. Bishop, photographer, h.as removed from 41, St. George's-road. X.W., to 19, Princess-road, Regent's Park-road, N.W. Leicester and Leicestershire Photographic Society.— June 24 (half day), Barkby and district. July 13, W.arwick. August 10, Chesterfield and Bolsover. September 14, Ashby and Coleorton. Northern PHOTOORAPmc and Scientific Association. — June 21, Lecture on T/te Cliemistry of the Dry Plate, by Mr. Charles Coulter. July 1, Ex- cursion to Natural History Department British Museum at South Kensington. Levtonstone Camera Club. — June 17, Hayes and Keston, Kent. Leader, Mr. F. Lohnieyer. The Club will proceed by the train leaving Cannon-street at quarter to three, arriving at New Beckenham at thirteen minutes past three. The Akkiliation of Photooraphic Societies.— The meeting of Judges of photographic Exhibitions, which has been already mentioned in our columns, will take place at 50, Great Russell-street, W.C, on Tuesday, June 20, at 7 p.m. Manchester Amateur Photographic Society.- June 17, Gawsworth and Marton. Leader, Mr. Fleming. Train, London-road (L. &N.W.), one o'clock p.m. for M,accleHlield. Fare, Is. 6rominences taken with tlie objective prism in Brazil; and photographs of the stations. These pictures, all taken together, greatly assisted those inspecting them in forming im idea of I eclipse work, its ends, and the difficulties connected with the meai s. i Interference Bands. — Among the exhibits at the conver- sazione was one which possesses a special interest to photographers. Since the advent in a pructical form of pinhole photfgrnphy much has been said about interference bands and their tffect upon th» image, indeed, the theoretical minimum diameter of a pinhole, capable of giving the best definition without interference bands de- stroying it, has been worked out by Lord Raleigh ; but what these bands are is not very well understood. In the example we refer to light was allowed to fall on a mirror thinly silvered, so that about half of the light is reflected and half transmitted. The two ray* pursue paths which are normally perpendicular, are reflected back by two ordinary mirrors, and, on meeting, interfere. The interesting part of this arrangement is that, by its m^ans, the bands can be re- flected on a screen; and this fact., together with the simplicity of the arrangements, will make the method a very useful lecture illustration. Professor Thorpe on Past and Present Astro>- Photography. — Professor Thorpe, lecturing on the Eclipse Expe- dition at the Royal Institution, explained how photography had altered the whole process of ob-erving solar eclipses. Siri.ce the red- letter day, he said, in 18C0, when Warren de la Rue fir^t applied his photo-heliograph to the observation of the eclipse, the camera and its various modifications had come into use so as to practically supplant ocular observation. The camera was not troubled with nervousness, and, having no imagination, simply set down actual facts. The selection of an appropriate site for viewing the eclipse was not with- out difficulties. As everything depended un getting right under the moon's shadow, they had to follow that shadow about all over the earth for each new eclipse. Professor Thorpe entered into considerable detailed explanation of the arrangements, and said that the observa- tions weie very successful. The various prominences, rifts, and configurations in the great gaseous envelope of the sun were most clearly brought out, while some most important results were expected from an examination of the spectroscopic slides. One interesting question had been practically settled by these observations — namely, that the corona suffered no change of structure during short periods, for the Brazil photograph, taken one hour and a half later, wa» identical with the African one. PIIOTOGR.\PHIC CONVENTION OF THE UNITE!) KINGDOM. Plymouth Mekti.ng, July 3 to 8, 1803. The following is an official synopsis of proceedings : — Monday, July 3. No excursion. Openinn; of the Convention, and Reception by th» Right Worshipful the Mayor of Plymouth (Mr. W. Law) at the Art Gallery and Lecture Hall of the Athenaeum (6.30 p.m.). Presi- dential Address (7.30 p.m.). Optical Lantern (9 p.m.). Tuesday, July 4. Steamer excursion to the Yealm and the River Tamar ; Tavistock. Wednesday, July 5. No excursion. General Meeting, 10 a m. Meeting of General Committee, 11 a.m. Convention Group at the Guildhall-square, 12 a.m. Papers, to be read from 2 p.m. to •'5.30 p.m. : — Recent Developers, by Mr. E. J. Wall. Lantern-Slide Making, by Mr. C. L. Mitchell, il.I). Artiitic Expression with the Hand Camera, by Mr. J. Guardia. Multiple Films, by ilr. S. Herbert Fry. Reception at the Guildhall, Devonport, by the Worshipful the Mayor of Devenport (Mr. W. Waycott), 7 p.m. Optical Lantern, 8 p.m. Papers, to be read from 8.30 to 10.30 p.m. : — Some Slides from tlie Marine Bia logical Laboratory, by Mr. J. T. Cunningham, U.K. The Special Properties of the Zeiss Aaastigmutic Lenses, by Dr. Paul RiiJoIph, read by Mr. J. Stuart. Photography in llelation to Medical liecori and Demonstration, by Mr. A. Pringle. The morning and afternoon meetings will be held at the Western Law (Jourt. The r^'Cept on and. papers in the evening will take place at the Guildhall, Devonport. June 23, 1893] THE BRITISH JOURNA.L OF PHOTOGRAPHY. Thubspay, J iri-Y 6. ICxcursion to Launceston, Totneo, nnd down the Dart. Ijender. Mr. H. Hansford Wortli (leaving Millbay at ".•').') a.m.). K.vcursion Id Looc. Leader, .Mr. O. Barnston (leaving Millbay at 9.10 a.m.). Excursion to Cboeawing. Leader, Mr. J. S. llawker(leaving I'ly- inouth by steamer about 8.4-5 a.m.). Paperu to 1»> read from rt p.m. to 10.30 p.m. i—'S'oOTi- Points in Connexion imth Development, by Mr. C H. Bothamley. ()n the Power of Compemat.imj in Development for Vaiiution in ICrjMmre, by Profes.«or W. K. Burton. Latitude in Kifxfttie and Speed of PUt'ten, by Dr. F. Hurter and Mr. V. C. Driffield. Our Pictorial Failures, by the Kev. F. C. Lambert, M.-'V. The papers will be read the Western Law Court. Friday, .July 7. Excursion to Lydford. Leader, Mr. R. Burnard (leaving Millbay, North-road, or Mutley at 7.6.') a.m. Excursion to Bickleigh Vale, Leader, Mr. Crook or Mr. Moore (leaving Plymouth at 8.2,") or 11.20 a.m.). Excursion to Dockyard and Keyham, Cattewater. Leader, Mr. Tweedy (leaving Plymouth at 8.2.5 or 11.2"> a.m.). Dinner and Smnking Concert at the Western Law Court at 6.30 p.m. Saturday, .Ivly 8. Council meeting, 9.30 a.m. Excursion to I'rincetown. Leader, Mr. Burnard (leaving Millbay, North-road, or Mutley at 8.4.5 a.m.). Excursion to Ivybridge (leaving Plymouth at 10.40 a.m.). Excursion to ^"irtuous Lady Mines. Leader, Mr. II. Alger (leaving Millbay at 11.20 a.m.). All communications after June 27 should be addressed, the Hon. Secretary, Photographic Convention, Art Gallery, Athenajum- buildings, Plymouth. K. A NEW STUDIO. ^K, Mkssb.s. Hills & Saundeus, the well-known photographers of ^t. Oxford, Eton, Harrow, &c., have recently opened a new photographic ^^ studio in London. It is situated in Sloane-glreet, in the very heart of H ithe fashionable quarter of the town, among the denizens of wliieh the ^^ quality of Messrs. Hills and Saunders' work entitles them to expect a good sliaie of patronage. The suits of rooms occupied by tlie firm is entirely on the ground floor, two tastefully furnished reception rooms, adorned with a good collection of specimens, and presenting a most agreeable coup-d'ceil to the visitor, being immediately reached from the front entrance. To the right of the second of these is the dressing-room, an unusually attractive and spacious apartment, the appointments and decorations of which are in faultless tast3. This admits a sitter to the studio. The studio is of une.xceptionable size, being seventy feet long and twenty-three feet wide, and of proportional height. It was formerly, we were told, the music room of a town mansion. Around the walls are arranged a large number of groups representing the Eton and Harrow cricket and football teams for a great many years past. The studio has evidently been arranged with an eye to handsomeness of effect, and the accessories, backgrounds, &c., are of an artistic nature. The electric light is exclusively employed, a Pilsen lamp, with a con- cave radiator, being swung so as to bo readily adjustable. Power is derived from the Company's mains a light of eight to fifteen thousand candle power being obtained, the average exposure being from one to two seconds, which may, on occasion, be considerably reduced for children, &c. The new studio, which we understand was arranged partly in accordance with the ideas of Mr. A. Cowan, is. illuminated throughout with the electric light. It is a most elegant and luxurious addition to metropolitan studios, among which it is in several respects unique. ♦ • REVERSED NEGATIVES. AxL who have had any experience of the different photo-mechanical processes, or of carbon or pigment printing are aware of the impor- tant part whicli reversed negatives play in such processes ; and there is no doubt that many workers have been deterred from taking up the carbon process, in spite of its beauty and permanence, by the necessities represented by reversed negatives on one hand, and double transfer on the other. In ordinary practice, such negativea as I have referred to are prepared either by making a negative in the camera from a tran.sparency (a carbon transparency by preference, or else by stripping the original negative film and reversing it), the process being often varied by mounting the stripped film on a collodion or gelatine skin, so that it may be conveniently handled, and, if necessary, used from either side. It has been hoped that the use of celluloid films would enable the negatives taken upon them to be used either direct or reversed; but, although this may be possible with some " rollable " films, the ordinary cut films show a marked loss of a defini- tion if printed from the wrong side. Having occasion to deal with some cases in which reversed nega- tives were needed, I have been much impressed by the advantage that would be gained could such be produced from original negatives by one process instead of by two or three, and some experiences which had occurred to me in connexion with the reversing action of light (now so fully recognised) led me to think that assistance might be found in that direction. I remembered that a good many years ago I carefully prepared a batch of emulsion for lantern plates, which was supposed to be very slow, but with which I could only print nega- tives. I wondered at the time what was wrong, and in my inexpe- rience I threw the emulsion away, but since then I have learned to put the trouble down to the then practically unrecognised action of light reversal. Remembering this, and calling to mind what has been more recently written on the subject, I took up a series of experiments which have led me to a successful result. I find that the process of making a negative from a negative by direct contact printing is as simple as printing an ordinary trans- parency or making a bromide prmt, the only difference being that the print is made on an ordinary bromide negative plate, and that the exposure is extended so as to secure the reversal of the im^e without over-doing the operation. Working with Ilford ordinary plates the exposure required with a good crisp negative I find to be about five seconds in strong daylight, not direct sunshine, the exposure being increased if the fight be poor, even up to thirty seconds at about sun.»et. It is here, of course, that judgment becomes neceasary, both as to the quality of the negative to be reproduced and the actinic power of the light employed, but only in the same degree as in bromide paper printing. Jly earlier experiments were with the ordinary hydroquinone developer, and were successful, though development was slow. I prefer for this purpose to use pyro and ammonia, or best of all the new metol-Hauff, which, with a little bromide, works like a charm, the reversed negative coming up with all the crispness and force of an original. In the case of over-exposure, the image sometimes appears first as a ghost of a positive which sinks in and dies away as the negative comes up, but in such cases the result will not be satis- factory. If the exposure has been about correct, the negative will develop out in just the ordinary way, except that, the light having penetrated the film so deeply, care must be taken in judging density by looking through the film. I find that I can depend definitely upon obtaining good reversed negatives every time by being careful, and I very cordially invite all who may be interested in such matters to take up the process, which theoretially should be a perfect one, and with the experience to be gained by more extended trial may, I believe, be made perfect in practice. Wm. Bishop. COMPENSATION IN DEVELOPMENT FOR VARIATIONS IN EXPOSURE. [ London and Provincial Photo<^rapliic Association.] AcooBDiNO to promise, I have brought to show you to-night the result of a few experiments on the question of " Compensation in Development for Variations in Exposure," on the lines suggested by Mr. Burton's paper. When the question was brought up at the last meeting, I ventured to say that, from my own experience, I did not think it was possible to get negatives giving identical prints, or so nearly similar, that an experienced photographer could not tell the difference between two negatives — one having the so-called correct exposure, and the other forty or eighty times more — unless the range of tones was practically limited to, say, two tones or little more. In the examples I have developi <1, one plate may be considered to have had a normal exposure, viz., u -eries of light intensities varying from half a second to thirty-two seoonds, each step being double that of the previous one, and-in the others an over-exposure of thirty-two times, viz., the first having sixteen seconds, and the last of the seven 1024 seconds. I here show you the results, the negatives themselves, and also the curves of the densities as measured by the photometer, and 300 THE BRITISfl JOURNAL OF PHOTOGRAPHY. [June 23, 1803 I scarcely think any one can imagine that the various negatives can by any possible means be considered identical. The first one (the normal exposure) was developed with — Pyro, 1 grain ; anhydrous sodium carbonate, 4 grains ; and potassium bromide, i grain ; and the three over-exposed ones respectively by doubling the pyro and bromide each time, the last one having eight grains of pyro and eight grains of bromide to the ounce, the alkali in each case being kept constant. The time of development varied from six minutes in the case of the normally exposed plate to one hour and forty minutes in the case of the eight-grain pyro one. I should explain here that what I tried to do was to make the lowest tint in the scale of each as nearly of the same density as I possibly could, leaving the higher ones to go on in their own way. I notice tliat Mr. Burton in liis article says his statement is not compatible at all with Messrs. Hurter & Driffield's, where they say the density ratios cannot be altered by development. Xow, I think it should be clearly understood what they did say, which, if I under- stand them, is this: They first define what they consider to be a perfect negative, as one in which " the opacities of the gradations are proportional to the light intensities," and, after many pages of mathe- matical reasoning and records of many experiments, they say : — " We have thus arrived at an answer to the question. Can nega- tives be produced such as we defined to be theoretically perfect ? and the answer is they can be produced, but only by so carefully adjust- ing the time to the intensity of the light that the exposures may fall between the period of correct representation." I must say, from my own trials of Mr. Burton's method, I cannot upset this contention. I may say here that I sent to four members of this Society duplicate pieces of each of the plates here shown, and 1 hope we may be favoured with the results of then- experiments in the same direction. All I can say, in conclusion, that, at the present time, I am not able by Mr. Burton's method to upset the theory that correct exposure is the principal determinary factor in the production of correctly graduated negatives. That abnormal] exposures can be made by alteration in development to give certain pictorial results, I am perfectly open to admit ; but, in a subject of this kind, that is not the question. But what we are talking about is. Can forty or oighty times the correct exposure be made to give identical results by modification in development ? A. Cowan. SUMMEE NOVELTIES IN APPAEATUS, ETC. E. & T. Underwood, Gbanville-street, Birmingham. When present at Messrs. Underwood's works, we were shown not merely specimens of their tourist cameras in the finished form, ready to be sent out, but the bodies and slides in various stages of completion, so that we could see the kind of work that is put in them. This we have little hesitation in sajing is of a very liigh degree of excellence. The cameras, brass work, lens mounts, &c., are all made on the premises. Messrs. Underwood profess to keep their makes of cameras from J to 15 x 12 in stock, but recently a difficulty has been experienced in adhering to this rule on account of the pressure of orders, which even while we were present were coming in by post. An especial favourite appears to be the "Club" camera, which, with all the requisite movements, is marked by great lightness and portabihty. Among Messrs. Underwood's recent introductions are several hand cameras, which are distinguished by great simpHoity of movement. ♦' The Argosy " takes twelve plates in sheaths, the changing being effected from the outside. The sheaths being filled ready for exposure, lo remove the exposed plate the camera is held with the shutter end slightly down, and the small knob at top of right side pulled out. The plate then falls forward on to the floor of the camera. The knob is pushed in again, and the second plate is in position. Every time the knob is drawn out a plate is released, and every time the knob is pushed in a plate comes for- ward ready for release. The sheath is held in position at each of the four corners, and, when released from the top corner, it is not allowed to go loose into the body of the instrument, as is the case in many cameras. The lower corners are provided with pivots, working in grooves, the leturn of the plates being prevented by suitable springs, and the plates cannot in travelling get comerways, orossways, or in each other's way. The' "Argosy," which is fitted with finder, the ever-set shutter, and a single achromatic lens, is well made, and is exceedingly cheap. Two other varieties of hand camera are the " City " and the " Sphynx," the latter being of a superior variety, having a rectilinear euryseope working at /-6-7, fitted with an iris diaphragm. The shutter is a roller blind working between the lenses. The focussing gauge outside is set instantly from five feet to forty feet, or infinity, and the camera has finders for horizontal and vertical subjects, accurately centered and deeply sunk, and measures 9J x 5J x 4^ inches. To both the " City " and the " Sphynx " cameras a bellows changing arrangement of great neat- ness and excellence is fitted, by which the front plate is removed to the back with ease, smoothness, and certainty in a few seconds, and without possibility of hitch, dust, or undue wear. The door at the under side of camera is unfastened and allowed to hang down, and the larger knob at the end of camera is pulled out firmly. This draws away the spring pressure, which keeps the front plate up to register, and allows it to drop into the bellows. The plate is then grasped through the fiexible end of the bellows, conveyed along guides to the back, and pushed into place. The second plate of the series is then in focus and ready for exposure. The plate drops inside the bellows, clear of, and not touching, the folded sides, so that there is no wear or fric- tion, no dust, scrapings, or loose plates. The mouth of the bellows is attached to a metal frame, fitting in a groove, and is kept in place by a small milled head outside back of case. This milled head being screwed out a short distance, the bellows are raised, the sheaths taken out, fitted with plates, replaced and screwed in. Great simplicity is displayed in Messrs. Underwood's hand cameras, a feature which, with excellence and inexpensiveness, distinguishes all their apparatus. A handsome and serviceable 15 x 12 studio camera that we were shown exhibited these two latter qualities at their best. W. I. Chadwick, St. Mary's-street, Manchester. "What Lancashire thinks to-day England will think to-morrow," was a saying at one time frequently quoted, and that seems not unlikely to have some measure of application in the photographic world at the present time. To form an exact idea of the extent which what has been termed the stereoscopic revival has proceeded in amateur photographic circles, would be a dilHcult task that would, perhaps, not pay for the accomplishment ; but we are probably not far wrong in the conjecture that, be that extent great or little, the immediate future will witness a still more marked popularity for stereoscopic work of possibly greater endurance than tlie present rage for the hand camera. If only some exalted personage would set the fashion for binocular pictures, society at large would be sure to follow, with, maybe, more fcsthetic profit than is obtainable from the gentle art of pressing the button. Photography is under a debt of gratitude to Mr. Chadwick for his efforts to revive interest in binocular photography and the stereoscope, and that considerable success has rewarded those efforts is due to the by no means common circumstance of the advocate understanding liis case. For Mr. Chadwick not merely points the stereoscopic aspirant the way he should go, but lends him a helping liand. How valuable such assistance is, coming from an admittedly practical stereoscopist, everybody can appreciate who has encountered the vague apprehensions of abstruseness and difficulty which are commonly tliought to be involved in stereoscopic work. To sit under Mr. Chadwick for half an hour, however, is to have stereoscopic photography presented in an aspect that looks, as the phrase runs, as easy as shelling peas. It is not to be wondered, therefore, that Manchester, under the in- fluence of Mr. Chadwick, has developed quite a stereoscopic colony ; indeed, while in that town the other week, we were surprised at the number of amateurs who had adopted tliis fascinating branch of photo- graphy. That their number is so great is, of course, due to the presence in their midst of one so competent to instruct and advise as Mr. Chad- wick. The Chadwick stereoscopic camera, of which we spoke in terms of commendation two or three years ago, remains the perfection of what such an instrument should be. It takes plates of the size OJ x 4f , has two fronts, one for two lenses and one for a single lens, that are simply placed in situ by fitting under a brass cross piece on the front. These lens boards are reversible, so that the lenses may be packed inside the camera. The camera has a landscape-shape body ; swing back, with tlie centre of motion in the axis of the lens, and a spring roller for the June 2S, 1803] THE BRITISH JOURNAL OF PHOTOGRAPH V. 891 stereoscopic division. It is made rigid by pushing the baseboard for- ward, anil by an elonxntion of the sloVih which the camera screw is placed it is attached to the head with a minimum of difficulty. Bamett's single dark slides are used, and altogether the camera, which has a rising and falling front, and may at will be utilised for uprighl single pictures, is the heau iiUal of a well made, practicable instrument, without a single superfluous or complicated movement. Thb Chadwick Improved Hai?p Camera. The Chadwick Hand Camera embodies several features of a nature sufficiently distinctive to stamp it as possessing the character Mr. Chad- wick claims for it, namely, practical. As we have previously pointed out, it is not' a magazine camera, slides being used. It is of variable focus, from ibree to about six inches, focussing being effected by rack and pinion, ioperated by a milled head outside the camera, an aperture on the former showing a disc having an index for various distances. The lens fitted is either a single landscape at /-ll or a rapid rectilinear at/-7, the shutter being Kershaw's Instantaneous. For time exposures Mr. Chad- wick recommends the use of the cap, with, of course, the camera on the stand. The view meter consists of three pin heads on the top of the camera in the form of a triangle, with its base on the extreme edge, by which the picture is sighted. The camera has a focussing screen, and may b§ ^sed for both vertical and horizontal pictures. The lens front is removable and reversible, and the board having a boss when the latter operation is performed and a very short focus lens is used, the cap acts as a kind of plug. The size of the camera is 7 J x 5 J >c 4J, and the body is mahogany, polished black. Several improvements have recently beea applied to the camera. A rise and fall front, and a swing back for both upright and horizontal pictures, have been applied, and also a side swing; these adjustments do not in any way add to the size or weight, the only visible difference being two little screw heads on the side. Scott's single dark slides for plates, or the double variety for films, are used with the camera, and as these slides are extremely light and port- able, a Qopsidierable number of them may be carried about in the pocket for use as oeoasion demands. Like alt Mr. Chadwick's productions, the Practical hand camera is at once simple and effective, and has the advantage of having been worked put by one whom experience has given a grip of the requirements of amateur photographers. PniLir Harris &■ Co., Birminoiiaji. The Cytox Hand Camera of Messrs. Philip Harris* Co. lias many points of novelty. It is of the fixed-focus type, and a small aperture in the front cuts off light from the lens, which is fitted with the usual diaphragms. A shutj^r of the oscUlating-plate pattern, giving a minimum exposure of one-twentieth of a second, is employed. The plates are contained in ■i.,,!i . ,: sheaths which may be bent to admit plates of any thickness. These sheaths are covered with a dead black of peculiar excellence, the prepara- tion of which we are informed is a secret. The lens has iris diaphragms adjustable from the outside, and the camera may be used vertically or horizontally. To remove a sheath with an exposed plate a button on the top of the camera is pressed. The camera is used as follows : — Having placed the dry plates or films in the sheaths, place the camera on the table, front downwards, then pack the sheaths one on the top of the other, inside the camera. The first one must be carefully placed, so that the front of sheath touches the wooden (c) stop in camera ; when this fii-st sheath has been put into position one hand should be placed in the camera, and the back of the fingers of this hand should slightly press the bottom of the sheath to keep it in its proper position, while the other sheaths are being put in with the other hand ; the wires of sheaths must be in the grooves (n) on either side. When the twelve plates (or any less number) have been placed, insert the spring inside the camera, seeing that the wires of plate follow the grooves (ii). To change the plates, press the button a on the top of camera, which presses the plunger inside and forces the front plate below the stop c. The plate then falls to the bottoip of the camera, face downwards, protected from the light by the sheath and screens. Tlte second plate is now pressed forward automatically by the sjaring tit back, and is removed just like the first. When the camera is used in the vertical position the exposed plate must be fixed by screwing up the button II. The shutter is very simple, bat very good. For instantaneous exposures pull the string as far as it will go, the shutter is then set','and may be released by a very slight pressure of the button at aide. For tibae- exposures pull the string to the first catch, then, after exposure, press the button to close aperture. It is the habit of Messrs. Harris before selling a Cytpx to a onston^^ to exhibit its capabilities by taking a picture with it. . : Among the firm's other novelties is an electric lamp for the dark room, in which the battery consists of five cells, with an arrangement for raising or lowering the carbons and zincs of all five cells simultaneously, and fixing them, when raised, by means of side screws to allow carbons and zincs to drain, and stop action and waste of zincs. When required for use, carbons and zincs are lowered by unscrewing side screw. The lamp is five-candle power, and when ruby light is required the niby cylinder is over it. When required for lighting, the cylinder is removed. Bichro- mate solution is to be used in the inner cells, and dilute sulphuric acid (1 j^n 35) in the outer cells. The framework is mahogany, polished, and the outer cells glass. Any number of cells may be used up to five, or any cell may be used separately. As showing the great utility of photography to business firms, we may men- tion that at the time of our visit Mr, Belcher, the manager, was busily engaged in piiotographing chemical apparatus for a new catalogue, be explaining to us that this would obviate the engraver misdrawing the specimens, which was probable, as they were required to be arranged in a particular way. The pl^ojtpp^plup catalogue pontawQ patttoolMS of cheap and useful sets, &o. ■.!,. ..i. . .;..!i.i; „•■.,..;.•;; 'ft ■: ;v.i".v, " ' ■ .•.;!.■ J. !) r.j Abcher & Sons, Lord-stbeet, LrvERPodii;' '■'■■"'''' ■ . . .■ .■.,--:■; •■;•,- i-.' : ■•: .i* The " Archer " combinedhand or stand camera, hashad seveM iiilprd*M] ments applied to it since its introduction a few w;eeksago, among others, tlie slides are held at the top and sides of the box, in wliich the camera proper is contained, thus economising space. For closing the hack and fronb spring catches are applied. Messrs. Archer are also introducing an exceedingly light tripod stand, the legs of which, when opened up, are ^epuiedl by a simple spring ca^h,' . The stand is made of polished walnut. ©ut iEJritorial STatle. «;■ -■ : ■■ The Champion Folding Lamp. In the following cut we show, both folded and erected, a lamp (prt>- curable of all dealers, price one shilling), which occupies very litd© pace when folded for travelling, wbile^ when well ventilated. set up, it is roomy 8 D^ £92 THE BKITISH JOURNAL OF PHOTOCmAPHV. [June 23, 1893 itfiCJS-JrT i'ATENTB. APPUCATlONS FOR PATENTS. Xo. 11,789.— "Improvements in Ptotqgraphic Cameras." A. W. PococK.— Dated June 15, 1893. - ; "" ' No. 1 1 , 796. — " An Improvenient in Photography. " F. STBSSSEitG. —Dated June 15, 1893. .. . . • : . No. 11,823.— " Improvement in Cameras." Communicated by E. Decker, P. R. J. WiUAH.—haUd June 15, 18J3. No. 11,841.— "Improvements in Pliotograpbic Cameras." G. D. HtJSRES. —Dated June \%, 1893. ' No. Ii;8e9.— " Changing Arrangement for Hand Cameras." G. S. Whit- viKUi.— Dated June 16, 1S93. ' • No. 11, 87i— "Improvements in Photographic Developers." Communicated by the Actien Gesellschaft fur Anilin Fabrikation. C. D. kVKl..— Dated June , 16, 1893. • • PATENTS COMPLBTED. TMPBOVKMINTS in AMD RELATING TO TBK COLOUBISO OK PHOTOOBAPHIC Pkints, Transparencies, and Nkgativks. No. 7343. Charles Klaby, 22, Rue de Beaune, Paris, France. Mi^yXi, 1893.. The object of this invention is to provide a method and means for colouring photographs, which diHers from othi i irnthods in the beauty of the effects which may be obtained without any previous preparatibn of the photograph to receive the colours. • ^ The invention is applicable to photographic prints onpaper as well as to transparencies and lantern slides on glass, and is also suitable for the retouch- ing of negatives. The improved method consists in colouring the photograph, if a paper print, ■ by the application of colours, prepared as hereinafter described, to the back of the photograph, so that they penetrate the paper and appear underneath the photographic tilm as seen from the face of the picture. This process, which I have termed " Chromophotophane," does not require ■ any previous preparation of the usual paper print, eithet for rendering it trans- parent or translucid, or for removing the paper wholly or partly from the back of the film. The colours are applicable to trau.sparencies, lantern slides, and negatives, in fact, to any photographic film either on glass, or paper, or without, being applied to the back or front as may be most suitable. It does not interfere with the subsequent burnishing of paper prints. The colours are prepared as follows : — Aniline colours are taken and dissolved either in water or in alcohol, such solutions being made as strong as possible whether by use of heat or in the cold. It has been found that some of the aniline colours so prepared will not soak properly into or through the paper aa this process requires, and in such cases, which can be found by experiment, it is necessary and suHicient to add acetic acid to the alcohol. The number of colours, natural or by mixture, which can thus' be prepared is practically without limit, and will afford every necessary colour for this purpose. The colours so made should be put up in bottles, which should be kept tightly corked. The vehicle or medium for the emjiloyment of these colours is alcohol, or a mixture of alcohol and acetic acid. By use of this medium the artist may reduce any of the different colours to any state of tenuity that may be necessary to give the desired tint. lo colour a photograph, the latter is placed face downwards on a retouching desk or the like, so that it may be viewed by transmitted light, and the design on the face may be sufficiently visible from the back to guide the artist in colouring the photograph. The colours are laid on in the usual way with a brush or pencil, care being taken not to pass over the outlines. The colours immediately soak through the texture of the paper, and act more as dyes than surface colours. They quickly dry through evaporation of their solvent. The photograph may be lifted from time to time to ascertain the tint appearing beneath the film, so that the amount of colour used may be made proportionate to the tint desired, a second coating, or several if needed, being added until the desired depth of colour tint is obtained. Photographs coloured in this manner exhibit a delicacy of tint combined with photographic clearness unattainable when colour is applied to the face of the photograph. Ne^tives may be touched by colouring with the described colours according to their actinic absorbent capacities, and the use of such colours offers to the retoucher opportunity of delicacy of treatment unattainable by the ordinary process. They are applied to the face of such negative. The claims are : — 1. The method of colouring photographic prints on paper consisting in applying to the back of such prints colours dissolved in a medium adapted to soak through the paper, and appear beneath the photographic film on the face thereof. 2. The method of preparing colours for use in the colour- ing of photographic paper prints as described, or for the colouring of other photographic prints such as transparencies, optical slides, or lor retouching negatives, consisting in dissolving aniline colours in water, or alcohol, or a a mixture of alcohol and acetic acid. 3. The method of colouring photo- graphic prints on paper, transparencies, optical slides, or glass, or other carrying vehicle, consisting in applying to the back of paper supported films, or to the face of glass supjjorteil films, or to the back or face of unsupported films, aniline colours dissolved in water, or in alcohol, or in a mixture of alcohol and acetic acid, and diluted with a medium composed of alcohol, or of a mixture of alcohol and acetic acid. 4. The method of retouching negatives consisting in applying to their surface aniline colours in solution of suitable tenuity, and of more or less actinic 'absorbent nature substantially as described. iMPBOVKMENTS KKLATING TO PHOTOGRAPHIC APPARATUS. No. 10,796. Hermann Mackenstiin, 6, Rue du Havre, Paris, France. Man 13, 1893. This invention relates to an improved mode of constructing photographic frames with rollers, in which the sensitive material (pellicle, paper, fabric, and the like) iorm a continuous strip of any length, previously »"ound upon a cylinder fioni which it is unwound to a suitable length for winding upon a second cylinder when it is necessary to bring in Iront of the aperture of the frame another part of the strip in order to make a new plate. All the parts of my improved frame have been carefully thought out, and are combined in such a nianner that, while reducing as much as practicable the size of the frame, I ensure the regular operation ol the system, prevent the light from deteriorating in any case the roll of sensitive material, and render the use of the frame as convenient as {M)8sible. The said Irame is also provided with an automatic counter, which indicates to the ojierator the numher of exposures he has already given, and con8ee marked 1 to 12, and 3, and so on ; thus all together I 4>btelonging thereto, and m lieu of this employ a ratchet device which at the proper moment will automatically prevent the continuation of the movement lor winding up the sensitive material, this ratchet device being actuated by the winding-up mechanism itself. After the system has thus betn fixed, it wdl be sufficient for releasing it to move the ratchet device by hand back to its original position. The series or mark number which the light produces upon each plate at the -same time as the number of the exposure is obtained iu a similar manner to the latter by combining, every time when this may appear useful, two alphabets or two series of figures or signs, so that each letter of one of the alphabets may serve for marking a great number of plates, by employing it alone first, and ithen with each of the letters of the other alphabet successively. Thus, for example, the frame may be provided at the upper or lower part with a rule bearing the letters from A to Q. all the plates of the first series— that is to say, obtained with a first roll of material — may be marked simply with A at the top. Those of the second series may be marked with A at the top, and with A telow those of.the third, fourth, fifth, and sixth, and further series may always bear A at the upper part ; but B, C, D, E, and so on respectively, at the lower jiart. There are, therefore, eighteen series of plates marked with A at the top. I replace the A by B at the upper part for the following eighteen series with the ring the desireil letters or numbers, and which is turned through a division in each change of aericii so a« to more to the upper part the ebaracten which are suitable. Th««« chanettn, beioc then ezpoied at an aperture piereeense with what I have termed the series-numbering device — that is to say, rules or the discs— and retain only the ezpoanre- numbering device by augmenting the number of the discs, the numbered wheels and the apertures, and also the actuating wheels, as mnch as may be necessary. On the other hand, instead of using wheels with twelve teeth and putting twelve numbt^rs upon the discs and upon tlie wheels behind the ajwrtures in the box, I may provide these discs ana wheels with the figures from 0 to 9, and employ wheels having only ten teeth, so that the first disc marks the uuitx, the second the tens, the third the hundreds, the fourth the thousands, and so on, and in the same manner for the wheels placed behind the apertures. Kach plate will then be designated only by a single number indicatmg its order in the plates made since the commencement of the excursion and by the invariable number of the frame. I will now proceeil to describe the s)iecial construction of the delivery and receiving cylinders, upou which is wound the pellicle or other sensitive material. Each cylinder is made of two parts, connected by a longitudinal hinge. After opening the cylinder 1 introerndtting the turning of the receiving rollers in order to give a movement of translation to the atrip or band of materiaL This arrangement consists in providing the rod of the key with a shoulder where it passes through the centre of a small cylinder, against which shoulder acts a spring, which tends to push it back to the outside, but prevents its complete removal by means of a screw or other stop. On the other hand, the extremity of the rod of this key is screw-threaded, and it is sufficient to turn it by pressing above, so as to overcome the resi.stance of the spring for enabling it to be screwed upon the axis and unite it therewith without danger that it will turn the axis the wrong way, because, if turned to the left, it would be unscrewed. It will be readily understood that the system herein described may be applied to frames of any dimensions and any proportions, and that tke rollers and axes, which are in this case parallel with the narrow sides, luight, on the contrary, be parallel with the large sides. In either case they may be mounted upon the box itself, and also the whole mechanism and the frames might lie dispen.sed with, which would not make any material difference in the system. On the other hand, the position of the delivery roller and of the receiving roller might be reversed ; that is to say, I might place that which is below at the top, and cic* versd. This would simply necessitate the placing of the key and ot the exposure-numbering devices on the ielt of the box in lieu of placing them on the right-hand side. Instead of the words attributed to him at the meeting of the London and Provincial Photographic Association, on June 8, .Mr. K. Child Baylcy said "tbat it was quite possible, by suitable development, to produce a uegaiive which, showing the full number of gradations the plate could register, was printable throughout. A negative which possessed a scale of densities greater ", than could be printed was simply improjierly developed." S94 THE BRITISH JOURNAIi OF PHOTOGRAPHY. [June 23, 1893 ' '■flf/'' mtHitiQ^ Of §:otittu0* MEETINGS OF SOOT^.TTKB ^OK NEXT WEEK. Date of Meeting. Name of Society. Place of Meeting. Asso. Studio, Nethergite, Dundee. „ 26 North Middlesex ......; Richmond ; Birmingham Photo. Society ... Great Britain (Technical) Jnbilee Honse, Homsey-road, N. 26 Greyhound Hotel, Kiohmond. .. 27.'. Club Room, Colonnade Hotel. :; 27:::::::::::: 50, Great llussoU.st., Bloomsbury. 206, Mare-street, HackBey. " 27".'.'.'....... Halifax Camera Clnb ,... 27 Springfield Barracks, Lancaster. ,' 87.!. 165, Constitution-street, Leith. .. W " ■ ho**' Paisley Warrington i,, ; ; Bath ..;.:. > 9, Gauze-etreet, Paisley. . Museum, Bold-street, Warrington. Roy.Lit. & Sc. Inst., Terrace-walks. ' !! 28 . Bank Chambers, Hargreaves-street. " m:::;::: The Assembly Rooms, High-road. :: i-::;;::: Anderton's Hotel. neet-8treet,K.C. The Studio, 15, Cambridge-arcade; Glcsop Dale .. Mechanics' Hall, Halifax. .. 29 Wnll ;.. 71,' Prospect-street, Hull. :: i9.;.:::.:.::; Liverpool Amateur. Percy-buildings, Eberle-street. „ 29 Champion Hotel, 15, Aldersgate^st. ;; 29 Oldham ; ■. •The Lyceum, Union-street, Oldham, „ 30 30 Public Hall.George-stroet, Croydon, .. 30 :: ;■■ ;; So" ** The Palace," Maidstone, „ 30 Tenby Hotel, Swansea.- Julyl Hull 71, Prospect-street, Hull. LONDON AND PROVINCIAL PHOTOGRAPHIC ASSOCIATION. June 15, — Mr. A. Haddon in the chair. , Receipt of a copy of the Amateur JPhqtographei'a Annual for -1893 was acknowledged. Prospectuses of the new Central Photographic Club Company were dis- tributed. Mr. J. Howson passed ronnd the original prints from whicli the reproduc- tions in the June number oi Photographic Scraps illustrating Mr. W. K . Burton's rem^ks on density ratios were made made. Compensation in Development for Variations in Exposure. Apropos of Mr. Burton's recently published experiments, Mr. Alexander Cowan read a paper on the above subject [see page 389]. Mr. W. E. Dkbenham said that Mr. Cowan had not quoted the part of Messrs. Hurler & Driffield's theory which Mr. Burton had called in question. One might have subjects which were not within the range of correct exposure. The question was this : Seeing tliat we could not ensure a. subject which sliall only have its intensities within the limit of correct gradation, when the expo- sures are beyond the limit, can we by development differentiate so as to show considerable difference between tlie brightness of one high light and another high light ? If we can differentiate those light.s which are out of wliat is known as the liiiiit of correct exposure, and make tliem show gradation .something resembling the original, that is a valuable achievement. Mr. Burton sliowed an instance of it in direct contradiction of Messrs. Hurter & Driffield. Mr. P. Everitt disputed the claim that the prints shown were identicai. Mr. Howson said Mr. Burton's point was, Can we alter tlie ratios of the densities by a difference of development ? He (Mr. Howson) contended that the prints shown proved that it could be done. Dr. Hurter, some time time ago, stated at the Photographic Society of Great Britain that the ratios could not be altered, but it W.1S the general opinion of photographers that they conld. The difference of opinion lay in the meaning of the terms, density and opacity. Mr. Cowan asserted that the ratio of gradation was not altered' by any known developer. Mr. Burton had said that two identical negatives could be obtained with varying exposures. Mr. Everitt thought that possibly the assertion of Mr. Burton had a double meaning. Did Mr. Burton mean that it was im'possible to say which was the over-exposed one in the sense that both prints were identically alike, or was it that you could not distinguish between the two which was which ? Mr. T.'BoLAS was of opinion that most photographers would conclude that of the prints shown the short exposure was the longer. Mr. DebEnham asked Mr. Cowan if there was atiy reason to suppose that, Carrying development a little le.ss far, he could have got a result that apjieared less exposed ? Mr. Cowan replied that in his experiments he had developed two interme- diate slips, and they bore out the contention that the curve was shortened. Mr. Everitt challenged Mr. Debenham to take the other side and .say there was no reason to suppose that by carrying development a little less far a less- exposed result could be obtained. Mr. S. Herbert Fry- had made tests whicli bore out the contention that there was a shortening of the scale. He had made twenty-five experiments, and had matched the prints, having used Thomas's Extra Rapid and Ilford Red Label. The universal average, as judged from the prints, was, the longer the exposure the shorter the distance where the prints went black, and where there was no detail at all,-thns -confirming the contention that over-exposure shortened the scale and compressed it. Mr. J. S. Teape showed results from the strips forwarded to him for testing by Mr. Cowan. He had erred slightly on the side of full exposure. Nos. 1 and 2 had normal exposure, one being developed for two, and the other for two and a half minutes. No. 3 had been developed by Burton's formula, sub- stituting four grains pf anhydrous sodium carbonate "to the ounce, one grain pyro, four sulphite, ami less than half a grain of bromide. No. 4 had been put for ten minutes id a twertty-grain solution of bromide, and then in a developer of 8 grains pyro, 20 bromide, 3 soda, and 96 sulphite. The imag« appeared in three minutes "and was complete in twelve'. It 'appeared to him' that it was only in the densest portion there was a little difference from the normally developed strips. Tlie normal exposures were from A second to 32' seconds ; the abnormal 16-1024 seconds. No. 5 had to the eye very little difference. It was put for thirty minutes in a twenty-grain solution of bromide, and developed the same as No. 4 ; the image appeared in six minutes attd was- veiled ; it was then jnit in the bromide solution for another five minutes, and then in the developer for seven minutes. He had also some negatives which he thought beat Mr. Burton's results. They had had 1 and' 40 secoUiis* exposure on a similar subject to Mi'. Burton's, and with his developer. Hft (Mr. Teape) would be inclined to take the one which received the longest expo- sure as the one which had had the shorter. '•'• Mr. CowAK remarked that he did not see how the range of gradations ti a negative could be tested without measurement. Quoting a. recent article-of Mr. Burton's on tentHtive development, itf which the writer stated having given forty times the nbrmal exposure, and the moment the image appeared' he instantly put on a very powerful developer. Which immediately intensified the image, Mr. Cowaii said he thought this of more-use than Mr. Burton's other article. ■ - , . . ■ Mr. Debenham said, years ago Mr. W. B. BoKoii had recommended one to- start with over-exposure and a normal developer, and, as soon as the image .ippeare'd, to remove the developer and apply bromide, keep that on for a short time, and then Jilace the plate in pyro and add ammonia, when density woiild-i be obtained without proportionately bringing up the weaker parts of tie nega- tive, which should be restrained. He often used the plan with success. Mr. Teape and Mr. Cowan had also found it priSeticable. Mr. Everitt said Mr. Cowan had sent him two normally and four over- exposed strips. Using anhydrous soda, after the lapse of a qdarter of an bour- no image appeared^ — possibly the soda was not anhydrous, or the bromidt ex- cessive. Washing off the developer, and using ordinary soda crystals as 4 : 1 of aiihydrons, and reducing the bromide to Mr. Burton's proportion, the plate developed in five minutes, the image being thin throughout. No. 5 was developed in 1 grain pyro, | bromide, 4 sulphite, and 4 soda to the ounce; it had more pluck throughout, taking five minutes to develop. No. 2 was de- veloped with 8 grains pyro, 8 bromide, 32 sulphite, 16 soda carbonate,; the image appeared very rapidly, and -was complete in twenty minutes. No. 3 ha d 8 pyro, 10 bromide, 32 sulphite, 12 soda crystals ; no image appeared for five minutes. Ten grains of soda were added in successive doses, and in seventeen- miniites the image appeared, and was complete in twenty-two minutes. No. 6' was tried with ammonia, and was developed in about five minutes. "What. struck him as peculiar was that there was no marked difference between the- normally and over-exposed plates. Mr. CfoWAN said that Dr. Hurter had stated that a range of 3 : 60 could not be detected pictorially, but was apparent on measurement. He did not think, the eye cotild detect these differences. Mr. Frt said that was an argument in favour of Mr. Burton. After other discussion the meeting closed. Holbom Camera Club. — .June 16, Mr. J. F. Stevens in the chair. — Mr, S. Herbert Fry gave a practical demonstration on the Sandell plate. Mr. f*Y said he had made it a practice never to develop a plate at a club meeting, but as most of the advantages of the Sandell jilate had been published, and the- members of the Holbom Camera Club were nothing if not practical, he had. decided to break that rule and develop a few plates. He passed round a number of prints from Sandell plates, and made a few remarks on the advaur tages and peculiarities of that plate. Two plates were afterwards developed, Mr. Fry demonstrating in a most practic-il way the method of developing these plates. On Saturday last, on the invitation of the President of the Hol- bom Cycling Club, the members of the -Camera Club visited Mill Hill, and sat- dow-n to tea with the members of the Cycling Club. North Middlesex Photographic Society.— June 12.— A question was askedi as to the best way of copying ;t Dagucrreotyjie, it being very difficult to avQid^ reflections. One member recoilimended that it should be done by artificial light by using two lamps, staiidiiig them at the sides some distance away, so that the light falls from each siile of the picture. Copying could often be done this way which w-ould be quite impossible by daylight. Mr. Stewart sug- gested that the method adopted in photographing .silver plate might be success- ful, viz., to form an artificial dew on the surface, which would prevent the- reflections from the bright surface of the plate. The paper of the evening was one by Mr. C. 0. Gregory on Dodc/es. He covered a very wide field, giving; hints on ever}- conceivable topic, such as exposure^for which he constructed, out of a small weight and piece of string a second iiietre — developing, dodging by means of a brush, intensification dodges by matt varnish, tissue paper, colours, pencils, &c., reduction by rubbing with spirit, printing, vignetting, printing in skies, &c. The paper was full of matter, and the simplicity of his- methods caused a good deal of amusement. Six new members were nominated. Harringay Photographic Society. — On Tlntrsday evening last the above Society held its first half-yearly conivrsan'one at the Public Hall, Finsbury Park, which was in every way a great success. It copsisted of a ]irogramme- of vocal and instrumental music, also an oxyliydrogen lantern entertainment. Tlie President (Mr. Dudley Towers), in his opening remarks, said tliat, owing to the great increase of its members, they had moved to larger premises and a more central position at 8, Station-road, Finsbury Park, where they had much, better accommodation for meetings, which in future will be on the second and- fourth Thursdiiys in each month. Tlie musical portion of the programme was- much appreciated. During the evening a set of beautifully coloured views of.' London and Paris were exhibited on the screen by Mr. Towers and Mr. BaU. Hackney Photogrraphic Society. — June 13, the President in the chair. — Mr. Hudson showed negatives developed with his modification of pyro-soda. Mr. Beckett showed three negatives, each having had a diffarent exposure varying from three to nine seconds,- the density in each being equal. Mr. S. J. Beckett showed and explained the Ilford F.xposure Meter. The Hon . Secre- June :23, 1893] THE BRITISH JODKNAL OF PHOTOGRAPHY. 306 TARV saiil wlien he wiw away from home he liad iiseint of it two ounces of common salt and half an ounce of hydrochloric acid are added." I do not know how I managed to transpose the alum and salt, or use " ounce" instead of "pint;" but, as compositors are not, as a rule, chemists, I suppose I must be to blame for it. I learnt all about the solubiUty of salt in hot and cold water when I was commencing chemistry. — I am, yours, etc., W. Lindsay. « GLASS SCREENS. To the Editor. ' Sib, — In reference to patent No. 9721 (Lauder Brothers), the speoifica. tion of which appears in your issue of tlie 12th inst., this idea has long ago been carried into practice. Apart from cases in which I have seen such screens in actual use, I may mention a large floral foreground upon glass which was some years ago in the stock rooms of Jlessrs. Percy Lund & Co., of Bradford. — I am, yours, &c., W. Ethklbert Henry. Samia, Ontario, May 29, 1893. Enscluerst to CorresponHents. PHOTOaBAPHS Rkgistebed :— Charles Walker Clarke, Devizes P;io;o!jra}ih of Prince 0/ Wales at Deviiet. Herbert William Hugrhefl, Dudley. — P/tofoyrapfis ofmineis at work. William Ernest Parkin Haiph, Taunton. — l^wtoyraph of a ijrouy of skeletons, Augnsftua Frcdoriok Perron, Bath.— PHotoi7rap?i ofW. Clark Russell, JBirj. James Thomson, Fermoy, 00. Cork.— PJiofo'jrap/i of Oie Duke of Devmshire ani oto<7ra]>ka of Dr. Andreve Wilson, F.R.a.E., CoomU Trmt Lecturer, Edinburgh. ?BON. — Tron phosphate is not used in photography. J. H.— Apply to Messrs. Avery, 81, Great Portland-street, W. T. S. II.— The address i> Edward L. Wilsou, 863, Broadway, New York. C. Lksty.— Vex, as unfixorts, which the landord is going to the expense of, but the studio is mine. Would the fact of the studio being on his posts give him any claim to it ? and will it he necessary to have an agreement or guarantee .' 3. The studio has met with the disapproval of the neighbours, inasmuch as it hinders the view, but does not stop the light. The house and ground are tlie landonl's, who i» quite in with it (or willing), they (the neighbours) have tried to frighten me by saying it will have to come down ; have I anything to fear with respect to it?" — fn reply : 1. If the value of any property is increased, as it will !» by the addition of new buildings, so will the rate value be increased accord- ingly. 2. A definite agreement had better be made as to this point. 3. If the new building obstruets any "ancient lights," it will certainly have to come down if the neighbours object. As we do not know what bye-laws the local authorities may have, we cannot say whether the erection contravenes them. Our correspondent, to be on the safe side in the matter, had better consult a solicitor who is familiar with bye-laws of the local authorities.. They vary in different towiis. 400 THE BRITISH JOURNAL OF VIIOTOGRAPHY. [June 23, 189y Jl. WpJUJiSON.— Though the fact of your having photographed a royal prince no doubt permits you to use the words " Under Koyal Patronage, ' the ac- ceptance of a copy of the picture by the Queen does not entitle you to dis- play the royal arms, by doing which you run the risk of a penalty. If you dissolve partnership, it seems to us that your partner, eiiually with yourself, may claim to have bad royal patronage. TThornhili, Square asks: "If I send a negative to a professional printer to have a donen prints made therefrom, and the negative breaks after a tew prints are obtained, cannot I sue the printer for the value of the negative -. In my case the Negative is a valuable one, as I cannot retake it without making a journey to the West of England to do so. I have made a claim for five guineas, and this the man repudiates entirely."— Th 3 printer can be sued for the live guineas, or any other amount for that matter, but we expect that nothing will l)e rcKovered. It is a recognised custom of trade that printers and enlargers are not responsible for breakage of negatives while in use or in transit This is usually stated on all prospectuses. Vbry Puzzled writes : " I should feel much obliged if you will kindly explain the ditticulty herein met with. The enclosed print is one of the interior of the parish church here, taken with a Ross lens. No. 3 stop, fifteen minutes exposure. On the right-hand side of print appears an inverted image of the east window. Ilfotd Ordinary plate used, backed with lampblack and gly- cerine. The same phenomenon appears in every negative taken with this lens of the church. Camera carefully examined and covered with focussing cloth during exposure."— There is a minute hole in the camera, probably in the front, cTos« to the lens flange, which produces another image after the manner of » "pinhole camera." This will easily be discovered by examining the interior of the camera in strong sunlight, with the head shielded with the focussing cloth. ♦ : — Skvebal correspondents in our next. . . Photogbaphio CLtiR— June 28, Leases up to Date. Received.— Glycin-An prints that have already been toned with gold, unless they happen to be so bad that any method of improving them is welcome, so we start with the idea of treating prints that have been passed through the hypo bath without gold toning. Most of our readers will have met, at some time, with the ^o-called " magic photographs," which make their appearance upon an apparently clean piece of paper upon immersion in .. ater in contact with another piece equally clean, or which uay be developed by the smoke of a cigar or cigarette. But aany are, perhaps, not aware that these are simply untoned ulViumen prints, bleached with bichloride of mercury, the in- visible image being reproduced by the action of very weak lij'po, ammonia, or any of tiie reagents employed under similar circumstances for the intensification of a gelatine negative. The tones produced by weak hypo, following bleaching by mercury, are of a most pleasing sepia tint, and for albumen paper, where brown tones are desired, this treatment answers well. But for gelatine papers, in consequence of the hardening ictiou of the bichloride and the persistency with which it clings to the gelatine, it is not to be recommended ; although, given thorough washing between the different operations, it will answer as well as with albumen. Sulphite of soda, in place of hypo, is, however, better, as it gives, perhaps, a better colour, with less risk of staining. A preferable bleaching solution is found in chloride of copper, or, better still, in bromide of copper. These salts may not be found in the ordinary photographic dark room or laboratory, but are easily extemporised out of readily obtainable materials. Sulphate of copper is obtainable at any village chemist's, and if half a drachm of that salt be dissolved in two ounces of water, and the same quantity of bromide of potassium or twenty grains of common salt be added, a solution will be formed containing bromide, or chloride of copper, as the case may be, either oi which will rapidly bleach the positive image, and convert it into bromide or chloride of silver. With either the mercury or copper salts there will, of course, be other metallicproducts formed in the bleaching process, though these do not appear to materially afifect the final result, provided a sufficient washing be given. A better solution consists, per- haps, in a weak mixture of bichromate of potash and hydro- chloric aci'l, ten grains of the former and twenty minims of the latter to the ounce of water. This bleaches the image with great rapidity, and, if the print be washed until the yellow tint of the l)ichromate is removed, it will be free from any foreign matter in the shape of metallic salts other than those of silver. , The bleaching is a merely mechanical operation, and the result does not greatly vary whatever may be the agent employed. The reduction or redevelopment is, perhaps, equally a mechanical process since the solution employed cannot possibly go beyond a certain point — that is, the complete re- duction of the silver haloid present. But a great difference may be made in the colour produced. If the image is con- verted into chloride, it will behave much in the same way as ordinary chloride paper under development — that is to say, it will with every developer we have tried, unless very powerful, produce a yellowish-brown colour that requires toning with gold or platinum in order to make it acceptable. If, however, a strong, fresh ferrous-oxalate developer be used, fairly good black and grey tones may be obtained if the paper be not exposed to a strong light before treitment. By ex- posure to light and treatment with a weak solution the result is precisely the same as with Alpha or other chloride paper. With a bromide-bleached image, amidol or metol, if employed of the usual negative strength, will give good black tones, but if reduced in strength, as for ordinary development of bromide papers, the colour shows a strong tendency to return to the yellow-brown of the fixed untoned print. Ferrous oxalate ex- hibits the same tendency, though not to the full extent of the two first named ; but in every case the strength of the reducing solution must be much greater than for ordinary bromide paper, more nearly that usually employed for negatives. The fixing, bleaching, and redevelopment of prints, instead of toning with gold, may seem a round-about way of arriving at a result ; but, as a matter of test, we have found it more rapid and less trouble than the ordinary process of gold-toning. The Japan Sxhibltion.— The recent exhibition of photo- graphs in Japan was chiefly composed of contributions of well-known pictures by English photographers, including a collection from the Camera Club. The credit of oru^anizing the E.\hibition belongs to Mr. W. K. Burton, who, according to opinions expressed in the native press, should be pleased at the result of his labours. About 300 pictures were hung, and the catalogue of them is a tasteful and artistic production. It was printed on tinted crape, with decorative designs on each page. Auxiliary Zilgrhtingr. — Every now and again the advantage, or otherwise, of a supplementary lighting of the plate in shortening exposures crops up. It did only last week amongst a few photo- graphic friends, when an animated discussion was carried on for an hour or more. Now, although it was denied by some that any extra detail could be obtained by secondary lighting, the effect being to cause fogging, contrary to the opinion of others all were agreed that in the case of some under-exposed plates, such as " snap- shots," a little judicious fogging of the shadows would often be an advantage, particularly when the negatives were to be used for stereoscopic transparencies or lantern slides. The Patent Office.— The Comptroller-General of Patents ha.» just issued a new series of abridged classes relating to agricultural and horticultural appliances. These abridgments are exceedingly useful as guides to the various specifications. They are, or rather used to be, issued on almost every subject, but unfortunately they are now in a very backward state. The latest issued relating to photography 404 THE BRITISH JOURNAL OF PHOTOGRAPHY. [June 30, 1893 only brings us to the end of 1833, though it bears the date of a couple of years later. The number of patents taken in connexion with photo- graphy during the past ten years is very large, and an abridgment of them would be of service to would-be patentees. Considering the profit realised by the Patent Office, it might be surmised that the compilation of the various abridgments would not have been allowed to fall so much in arrear as they are at present. " Our Climate." — The moderated temperature of the past week or so has been a great relief to the majority of photographers, and certainly to all workers of processes dependent upon gelatine in conjunction with the alkaline bichromates. At elevated temperatures, such as have recently been experienced, some of them, such as collo- type, Woodburytype, and the carbon process, are only worked with difficulty, even when the ordinary conditions of working are consider- ably modified. "With the thermometer at 88° in the shade, Wood- bury printing becomes almost, if not quite, impracticable, and collotype only workable when the plates are specially prepared to meet the exigencies of the ciise, which, by the way, may be changed in a few hours, and then the plates are no longer suitable. Few countries but ours can boast of a climate that can show a difference in the mid-day temperature of 27° in twenty-four hours, and, we might add, so far as gelatine photography is concerned, would desire it. PbotOe'raphing' the Voice. — Professor Hermann has recently succeeded in photographing the vowel sounds. The method employed was speaking them into a phonograph that reproduced them slowly. The vibrations were lecorded by a micro-telephone, in the vibrating drum of which was a smaller mirror, a ray of light from which recorded its vibrations on a travelling strip of sensitive paper. The idea of photographing sounds, however, is not new, for, when the phonograph first came out years ago, the late Professor Jenkin, of Edinburgh, together with Professor Ewin, made similar experiments to those of Professor Hermann. The phonograph, how- ever, used by these gentlemen was the original tinfoil instrument, and the sounds reproduced were somewhat crude. Notwithstanding this, some very interesting results were arrived at, and were published at the time. What would have been thought, prior to the invention of the phonograph, of any one who might have suggested that sounds could be photographed ? Colour Blindness. — The latest suggestion as to the cause of defective colour sense is that of Messrs. Blake and Franltlin, of Kansas, who have recently investigated the subject, and who attribute it to a product of civilisation, with the use of tobacco as a possible factor. It is said that colour blindness has been found to occur in about four per cent, of civilised European and American males,and with the Finlanders and Norwegians it is said to rise to five per cent., while the Butch go dowu to 1'43 per cent. According to these authorities, only seven-tenths of one per cent, of the full-blooded Indians of the Haskel Institute at Lawrence are colour-blind. It is not stated whether these Indians abstain from tobacco or not, but it is certain that the Dutch, who have a very low average assigned to them, do not. Colour blindness is suffered by many who really are not cognisant of the fact. Some photographers cannot possibly tone a batch of prints to anything like a uniform colour. One gentleman we know, who is an artist in every way, so far as photography and monochrome goes, occasionally colours a picture, and the result is little short of ridiculous. Although the execution is excellent, blues pre- dominate to such an extent that the picture is completely spoilt. Use Of Dark Rooms.— A few days ago we received a letter from a correspondent, an amateur touring with a camera in the West of England, complaining of the churlishness of some professional photographers in refusing the use of their dark room for the changin"- of plates or the development of a trial plate. Curiously enough, within a few hours we had letters from two photographers in the provinces complaining, in the one case, of the " impertinence," and in the other of the " nuisance " of amateurs with regard to the use of a dark room. Both of these gentlemen say that a large proportion of amateurs seem to demand the use of a dark room as a right rather than ask it as a favour, and invariably they will not tell their busi- ness to the reception-room attendant, but insist on seeing the principal, however busy he may be, to state their requirements. One also com- plains of the mess made when a plate is developed, and the litter left behind when plates are simply changed, the tourist often departing without even expressing thanks. Each year we receive similar com- plaints to these, on both sides. Amateurs en route should remember, and we believe the majority do, that in asking the use of a dark room they are asking a favoui^, and at the same time to bear in mind that they may be causing inconvenience to one whose time during business hours is money. —*■ A NEW DEVELOPER FOR GELATINE DRY PLATES.* The best experimental results were obtained with the tartrate and the metabisulphite of silver. Sulphite of silver, produced by precipitating nitrate of silver by its equivalent weight of sulphite of soda, is but little soluble in water, and is easily washed. The precipitate readily dissolved in a strong solution of sulphite of soda, but when combined with gelatine is less sensitive to electrolytic action tlian the tartrate. An impure double sulphite of silver and soda can be readily prepared by the addition of a solution of nitrate of silver to a saturated solution of sulphite of soda, as long as the precipitate formed dissolves on stirring. The nitrate of soda produced by this reaction, if not removed, seems to have a restraining action when the developer is prepared witli hydroquinone. As pyro is not as strongly influenced by the presence of nitrates, it may be fotmd practicable to prepare the silver salt in this manner in developers in which pyrogaUic acid is the reducing agent. In like manner ammonia may be used in argentic emulsions with pyro, though the addition of ammonia to a hydroquinone developer instantly arrests all reducing action, Developer No. 1. Formula. A. Argentic emulsion (prepared with silver tartrate) .5 ounces. Metabisulphite of soda 120 grains. B. Eikonogen 500 grains. Hydroquinone 100 „ Metabisulphite of soda 120 „ Distilled water (hot) 4 ounces. Pure glycerine 1 ounce. C. Carbonate of potash 144 grains. D. Caustic potash 270 to 300 grains. Distilled water (hot) J ounce. E. Bromide of potash 72 grains. Solution A is prepared by warming the argentic emidsion gently on a water bath in a glass or porcelain vessel of a capacity of about sixteen ounces. The metabisulphite of soda is stirred in dry im- mediately before incorporation with B. The eikonogen, hydroquinone, and metabisulphite (B) are mixed together dry, the water, heated nearly to the boiling point, is mingled with the glycerine and poured over the mass, which im- mediately dissolves if rapidly stirred, forming a clear golden yellow solution. The incorporation of A and B requires careful manipulation to avoid the precipitation of the gelatine or the reduction of the silver salt. These solutions are mixed at a temperature of 110° to 140° Fahr., a few drops of B are added to A, with rapid stirring continued for several minutes, until the emulsion, which at first darkened, becomes of a lighter shade. The remainder of B is then poured gradually, a little at a time, into solution A, stirring constantly. The emulsion should show but little change in colour ; it is at once neutralised by C, mixed dry. Carbonic acid is evolved, the emulsion * CoDcluded from page 375. June 30, 1895] THE BRITISH JOUKNAL OF PHOTOGRAPHY. 4M chftnpps to a dark drnb colour, and oorae gelatine separates as a dark- coloured precipitate. T) is then added in succesaivo portions, the colour of the emulsion changes to yellowish olive, and the precipitated gelatine redissolves. The amount of caustic potash required varies with the purity of the chemicals, and with any change in the formula. It is best to add to each ounce of the developer from two to four grains of caustic potash in excess of the quantity required to dissolve the precipitate. Care should be taken to determine tiie least amount that will form a permanent emulsion. If the proportion of potassium hydrate is too great, the combined silver and gelatine are precipitated. E is dissolved in the emulsion, and produces no apparent change in its appearance. Water is added sufficient to make the volume twelve ounces. The developer is bottled and cooled in a stream of water, with frequent shaking. Thus prepared, this developer is permanent, and but little affected by a moderate exposure to daylight. It is kept in bottles of dark- coloured glass wrapped in paper. The density and colour of the resulting negatives are much affected bv the relative proportion of eikonogen and hydroquinone in the above formula. In the proportions given, of two parts eikonogen to one part hydroquinone, the negatives produced are brilliant black in the high lights and of extreme density. With i40 grains of eikon- ogen and 80 grains hydroquinone, a ratio of three to one, the negatives are grey black, with relatively less density, but with extreme detail. Composition per Ounce of Developer No, 1. Eikonogen 16'7 grains. Hydroq\iinone 8'3 ,, Gelatine So „ Sulphites of soda 48' „ Carbonate of potash .... 12- „ Caustic potash 2o' „ Bromide of potassium ... C' „ Tartrate of silver 4'8 „ = 1 per cent. Glycerine 1'.5 draclim3 = 19 per cent. It should be noted that the object of using metabisulphite of soda in the above formula is to make the solutions A and B acid when incorporated, in order to diminish the reducing action of the eikonogen and hydroquinone upon the silver salt. It is more difficult to combine these solutions when alkaline; not infrequently metallic silver is precipitated. By careful manipulation, however, an equivalent quan- tity of neutral sulphite of soda may be substituted for the metabisulphite. Carbonate of potash is employed to neutralise the metabisulphite of soda ; it also greatly diminishes the action of potassium hydrate upon the gelatine film, preventing, at a temperature not exceeding 60' Fahr., the frilling or cutting of the edges of the film by the caustic alkali. Bromide of potash, in the presence of the great excess of alkaline salts in this developer, keeps the shadows clear and transparent, even with prolonged development. It has no restraining action, but, in the proportion of five to eight grains per ounce of developer, appears to act rather as an accelerator. This developer is adjusted by a trial development upon an extreme under-timed plate. The picture should appear in twenty-five to thirty seconds ; if longer, two to three grains of caustic potash and one to two grains of bromide of potassium are added to each ounce, to accelerate the action. There are evidences that this emulsion undergoes ripening if kept in a warm place, or if heated to a temperature of l^O" to 160° Fahr. for some hours ; the effect of this ripening remains to be investigated ; in some experiments a grey precipitate of silver bromide formed, and the electrolytic sensitiveness of the developer was increased. The objections to the above developer are the complicated formula and the large amount of the caustic alkali used, nece«itating develop- ment at a low temperature, not exceeding 60° Fahr., to avoid cutting the film. It also requires, to form a permanent emulsion, careful manipulation in compounding, and is much affected by any change in the purity of the chemicals used. Developmbnt. If the preparation is complicated, the development is correspondingly simple, and it is practicable, with a little experiance in its use, to obtain results that are unapproachable in density, and can only be equalled in detail by skilful manipulation with pyro. For instantaneous and imder-timed exposures ii^ developer is used without dilution; if desired, the action may be .restrained by the addition of water. A somewhat larger quantity of the developer is quired to properly cover the plate, owing to the viscidity of the emulsion. Two trays are used in development, the larger filled witk cold water, in which the smaller tray containing the developer partly floats. The negative is placed in the developer, and disappears from view Ijoneath the opaque emulsion; the tray is rockea until the picture comes up. It is only necessary, during the development, to occasionally rock the trays, the viscidity of the developer preventing unequal chemical action or the settling in spots upon the film of any sediment. The progress of the development is judged by the colour and ap- pearance of tlie plate when viewed by transmitted light ; the low lights and shadows are indicated by white spots in the film, whick become yellow-brown as the action proceeds; the development is stopped when the plate is opaque and a walnut-brown colour throughout. The negative is thoroughly washed, and the surface of the film is rubbed with the hand under a stream of cold water to remove tho adhering emulsion ; it is then fixed as usual. When working with plates that have received nearly equal ex- posure, tho time of development furnishes the best guide in obtaining the desired detail and density. There is a wide margin in time when instantaneous views and extreme under-exposures are developed. A good negative may be obtained in si-x to twelve minutes ; if the de- velopment be prolonged to half or three quarters of an hour, no harm is done, save that the negative, from mcreased density, will print very slowly. When desired, the development may be prolonged for one or two hours by changing the water in the outer tray, so that the developer is kept cool and the film uninjured. This developer may be used repeatedly without exhausting its power or staining the film. Intensification. Negatives that have undergone development may be intensified before fixing. For the primary development there is probably nothing better than pyro and soda ; no bromide is used, and the de- velopment is conducted so as to bring out all the detail possible, keep- ing back density in the high lights, in order that all parts of the image may be nearly uniformly dense. "When no more detail can be obtained, the negative is thoroughly rinsed in a stream of cold water and the secondary development conducted with any of the argentic developers, preferably with No. 1. The action is quite rapid and should bo carefully watched, lest the negative be over- intensified. The time required for secondary development is from three to fifteen minutes. The best guide is the appearance of the plate when viewed by transmitted light ; the development is finished when the negative becomes brown and opaque, without any light spots in the film. It is then immersed in cold water, the surface of the film is gently rubbed beneath the water with the hand or with absorbent cotton, to remove any adhering emulsion, and the negative is fixed with hypo in the usual manner. In this 8econd!ary development the action of the argentic emulsion appears to be an electrolytic building up of the image in metallic silver. This view is confirmed by the fact that a negative after fixing and washing may be slightly intensified by immersion in the argentic developer. In this case the electrolytic action is very slow, and could probably be made more energetic by increasing the sensi- tiveness of the emulsion, and indicates that it would be possible to make an argentic intensifier for negatives after fixing, by employing a very sensitive emulsion with ferrous sulphate as a reducing agent. Dbvblopkb No. 2. Formida (apothecaries' weight). A. Argentic emulsion (prepared with silver tartrate) 6 ounces. B. Sulphite of soda crystals (pure and neutral) 2 ouneas. Water (hot) 8 „ Amidol 120 grains. D, Bromide of potassium 8 grains. The argentic emulsion is gently warmed and the sulphite of sods solution B gradually mixed with it. If a precipitate of gelatime forms from too concentrated a solution, warm the emulsion on a I water bath and add gradually hot water until it dissolves. The emulsion, which is of a light olive colour, is allowed to cool ; C and D 406 THE BRITISH JOUENAL OF PHOTOGRAPHY. [June 30, 1893 are added dry and quickly dissolve ; the volume is made up to six- teen ounces by water, and the developer is immediately bottled to avoid absorption of oxygen. Tested with litmus paper, it should show a faint alkaline reaction. Composition per Ounce of Developer No. 2. Amidol 7-5 grains. Gelatine 3'1 „ Sulphite soda (free) 60- „ Sulphite soda (combined with silver salt) 25' „ Bromide of potassium O'S „ Silver tartrate 4'4 „ Glycerine I drachm = 8 "/„ This formula is less complicated and more easily prepared than No. 1. Only a minute quantity of alkali is required, the sulphite of soda acting as the accelerator, and in consequence, in prolonged development, there is little danger that the film will be attacked. It is also practicable to use a more sensitive argentic emulsion, prepared with the least propor- tion of gelatine that will restrain the silver tartrate, in order to in- crease the electrolytic action. This developer has been but little investigated ; it is probable that metol, or a mixture of matol and hydroquinone can be substituted for the amidol in the above formula, . and other alkalies employed, such as caustic lime, lithia, or baryta. Development. 'In hot weather, or when the development is greatly prolonged, it is .-advisable to keep the developer cool by an outer tray containing ice water, as heretofore described. Usually, with formula No. 2, this is not necessary, and the development is carried out much in the same manner as with pyro. The action is started with one ounce of the developer mixed with three to five ounces of water, two or three drops of a solution of Carbonate of potash 120 grains. Water 1 ounce, are added to each ounce of the mixed developer to accelerate the development. The strength is increased by the addition of fresh developer as the operation proceeds. It is only necessary to occasionally rock the tray. The action is less energetic than developer No. 1, and the negative does not so rapidly become opaque. The point at which to terminate the development is judged in the same manner as with pyro, save that, as there is no danger of fogging, it may be prolonged until the negative is dark and opaque. The plate is rinsed in water and fixed as usual. The negatives developed with amidol emulsion much re- semble in appearance those produced by pyro. With a developer of this class it would be practicable, when many negatives were developed, to employ a grooved rubber bath (such as are used for hypo) filled with the developer, and immersed in a vessel of cold water. The vertical position of the plates would prevent any sediment in the developer settling upon the films. Conclusion. The formulae here given are selected from nearly fifty experimental developers, prepared with various emulsified silver salts, combined with different developing agents. They illustrate the preparation of argentic emulsions and the combination, in a chemically passive condition, of such emulsions with reducing agents, in photographic developers. Much experimental work remains yet to be done to determine the formulae best adapted for use. The gelatine and the silver salts have . a tendency to slow the action in development. It is desirable that the time of development should be shortened, and the electrolytic .JtctioQ of the silver salt made more energetic. W. P, Jsnnct. « 'ON THE USE OF TIN-FOIL AS A SUPPORT FOR PHOTO-LITHOGRAPHIC TRANSFERS. [Photographic Society of Great Britain."] In the execution of photo-lithographic work, considerable difficulty is sometimes caused by the fact that a transfer prepared in the usual way on paper expands when damped, and also is stretched when pulled through the press in the process of transferring, The image on stone or zmc is tnerefore distorted, and, in cases in which it is im- portant that the reproduction should be to scale, elaborate precautions must be taken to ensure this. This difficulty is frequently met with in the Lithographic School of the School of Military Engineering, Chatham, which is in my charge. A considerable number of plans and drawings are there reproduced, and in all cases it is desirable that distortion should be avoided. In some cases this is of special im- portance. It has recently occurred to Mr. Husband, who is employed in the school as lithographic printer, that tin-foil might be used instead of paper in tlie preparation of transfers, so as to prevent distortion, and he. together with some of the military lithographers, have been working out the idea. Incidentally various other advantages in the use of tin-foil (besides that of non-distortion) have come to light, as will be seen presently. Mr. Husband was for many years iu charge of the Lithographic School while he was a non-commissioned officer and warrant officer in the Royal Engineers, and his name is known in connexion with his " papyrotint " process for photo-lithography in half-tone. He there- fore brings a very large amount of experience to bear on the question. It should be said at once that there is no new principle involved in the process. For line work it is merely a modification of the " papyrotype " process, introduced at the School of Military Engineer- ing by Captain Abney when he held my present appointment, while for half-tone work it is a modification of Mr. Husband's own "papyrotint " process. It is, in fact, quite possible that this identical tin-foil process is in use in other establishments, but I believe that no account of it has ever been published. The method of procedure is as follows : — (A) Papybotype Transfehs (fob Line Subjects). A zinc plate, such as is used for zincography, is damped with a dilute solution of gum arable (say one part in sixty parts water). A sheet of smooth tin-foil of the size of the transfer required is laid on the zinc plate, and the two are pulled through a lithographic press to- gether. The tin-foil adheres to the zinc plate, which thus enables it to be conveniently held during the process of coating with gelatine. A solution of chromated gelatine is prepared as follows : — Gelatine, common flake 1 ounce. Glycerine 2 drachms. Bichromate of potash 40 grains. Water (measured independently of the other constituents) 8 ounces. The gelatine is soaked in the water for half an hour (the water being cold) ; it is then dissolved by heat. When it is thoroughly dissolved, the glycerine and bichromate are added, and the whole stirred up together ; in three or four minutes the bichromate is dis- solved, and the mixture is ready for use. The above quantity is sufficient to coat about eight sheets of the size of half a sheet of foolscap. The surface of the tin-foil is then cleaned with a solution of caustic potash (strength about one part to forty parts water) to remove all grease, and the chromated gelatine solution, while still hot, is poured over it in the same way as collodion is used to coat a glass plate in wet-plate photography. The beaker containing the solution is covered with a piece of muslin, so that the liquid may be strained while it is poured out. The zinc must be slightly warmed to prevent the solution setting too quickly. The excess of solution is drained off, and as soon as the gelatine has set the plate is stood up to dry in a dark room. The process of drying takes about four hours at the ordinary temperature.^ If the room is warmed, it requires, of course, a much shorter time, but the results are inferior, as the transfer does not roll up so clean. The tin-foil is then peeled oS the zinc plate by lifting one comer of it with a knife. It may be kept in this condition about twelve days, or it may be used as soon as it is dry. It is placed in a photographic printing frame, and printed in the daylight behind a line negative in the ordinary way until the image is visible in all its details. After printing it is placed in water for three minutes, and then rolled in as usual with a rather soft lithographic ink of the following composition : — White virgin wax 1 ounce. Stearine 1 „ Common resin 1 „ Palm oil i „ Chalk litho printing ink 4 ounces. The transfer is immersed for three minutes in a solution of bichro- mate of potash (strength five grains to one ounce of water) and dried in a dark room. It is then exposed to daylight for a period of three minutes or upwards, according to the strength of the light, so as to harden the celati'.ie all over. This action should not, however, be carried too far. June 30, 1893] THE BRITISH JOURNAL OP JPHOTOORAPHY. 407 Before trAnsferrinjr, the trnnsfor is damped for about three minutes in a " dumping book" (iisin^ water only), and it is then pulled throujrh the press on a prepared stone or zinc plate. The after-processes are the same as when a transfer on paper has been used. Willi care, each sheet of tin-foil can be used a dozen or more times. Various examples are shown of subjects which have been photo- lithoffriiphed or photo-zincojfraphed under identical conditions, except that tin-foil has in some cases been used for the transfers, and in other cases paper. The stones or plates are quite vmtouched, and it will be seen that the results given by the metal transfers are sharper and cleaner than those obtained by paper. There is also decidedly less distortion in the former case. In the case of these prints, the images on stone or zinc obtained from the foil transfers are absolutely the same size as the negatives. The images obtained from paper transfers are all stretched to the extent of ^V to t'i? of an inch each way, i.e., ^\ to iV of an inch in a length of four to eight inches. The prints could, of course, be greatly improved by cleaning up and working on the stone or zinc, but it has been thought better to show the results obtained without any retouching or cleaning whatever. The cost of the work is practically the same in both methods of transfer. The advantages of the new method of preparing the transfers (as compared with paper transfers) are : — (1) The image on stone or zinc is not distorted. The' print, therefore, only has the distortion due to the stretching of the print itself in the press, and this can be eliminated by using a sufficiently stout paper and pulling the print dry. (2) The work is finer. (3j The work is cleaner, as specks, &c., can be more easily removed from the transfer. (4) The transfer does not buckle in the printing frame even when it tako^i a long time to print and the weather is damp. (o) Le«- "olution is required to be made for coating a transfer of any given size. (6) The transfer dries in about half the time. There is the slight dimdvantage that, m tlie case of zinc work, it is rather difficult to get broad lines to transfer solid ; they are apt to require retouching. It is thought that with more experience this difficulty will be over- come, especially if a softer ink is used in rolling up the transfer. (B) Papyiiotint Tbansfbes (fob Halp-tonb Subjects). The tin-foil is laid on a zinc plate and prepared as if for a line sub- ject; it is coated with a solution made up of : — Gelatine, common flake 2 ounces. Bichromate of potash 40 grains. Common salt 70 „ Calcium chloride 70 „ Ferricyanide of potassium 30 „ Chrome alum 8 „ Water (measured independently of other constituents) 8 ounces. The gelatine is dissolved in the water as in the previous case, and the other ingredients are then added ; the foil is dried at a tempera- ture of 70' to 80° Fahr. The coated tin-foil keeps in good condition for about twelve days. The transfer is printed under a half-tone negative, rolled in as for a line subject, and then dried. It is not necessary to immerse in a second bichromate bath. The transfer is damped in a " damping book," using dilute nitric acid (one part to sixty or eighty parts water) ; this tends to prevent the work becoming blurred through spreading. The transfer is then pulled through the press on a prepared zinc plate or stone, and the after-processes are carried out as usual. Examples are passed round showing how the tinfoil transfers com- pare with paper transfers. The cost is practically the same in both cases. The adoantages of the use of tin-foil as compared with paper are : — (1) The image on stone or zinc is not distorted. (2) The transfer can be cleaned more easily. (3) The transfer does not buckle in printing. (4) Less gelatine solution is required. (5) The transfer dries in about half the time. There is one very slight disadvantage, viz., that, if there are any inequalities in the roller u?ed for rolling in the transfer, the marks produced by them show up more thon in the case of paper transfers. Tin-foil transfers give more contrast in the prints, and this is an advantage as compared with the papyrotint process previously used at the School of Military Engineering, which very often produces too flat a print. (C) Kktbansfbiis. Tin-foil may also with advantage be used for retransfer work, by coating it with the composition ordinarily used for retransfer paper. The distortion, which with paper is unavoidable, can in this way be prevented, and this might be a matter of considerable importance. The re.«ults are somewliat better than those obtained with ordinary composition paper ; but the foil, when coated with composition, has the disadvantage, that it is not quite so easy to store without rbk of damage. (D) Obtiining Several Retbansfebs of Owe Subject. If a reversed negative is used, and a tin-foil transfer is prepared as described above, and, if this transfer is inked in as usual with transfer ink, a print can be taken from it on transfer paper as in the process of collotype printing. The paper print becomes, of course, a retransfer, and can bo transferred to stone or zinc. From the same original tin-foil transfer a number of paper retrans- fers can similarly be obtained. If these are all transferred to stone or zinc, the various stones or plates can, of course, be printed from at the same time. For line subjects this method has no advantage as regards the final result over the ordinary method of transferring the tin-foil transfer to a stone or plate ; but for half-tone subjects it seems to give much sharper and better results than the ordinary method. Also, in any case the retransfer method takes much less time, as the foil can be printed from while still wet, otherwise it has to be dried. The experiments are not sufficiently advanced to speak positively as to the retransfer method, because up to the present time there has been a difficulty as regards getting a suitable transfer paper. It is believed, however, that this difficulty has now been surmounted. (E) Process Work. One other use of the tin-foil transfer suggested by Mr. Husband is, as a means of preparing a half-tone process block. If the method is a practical one, it certainly might be of very great importance. I am not able to form an opinion as to whether it could be worked, and we have no facilities at the School of Military Engineering for testing the method. In any case, as process -^^ork does not appear to be of any use from a purely military point of 'view, we should not be able to expend time or money on such experiments. If a sheet of tin-foil is coated vi-ith It; gelatine solution as described above for the half-tone process, a mucb'thicker layer of solution being left on it than is required for lithographic work, the transfer obtained from such a sheet will have a much coarser grain. If such a transfer were transferred to zinc, and the metal etched with an acid, it seems possible that a half-tone process block could be obtained. Assuming that this would give satisfactory results, the method appears to be decidedly simpler than those ordinarily used. A coarse-grained transfer when printed from zinc gives a print such as that now passed round for your inspection. Those who have a practical acquaintance with process work will be able to judge whether Mr. Husband is right in suggesting that such transfers couJd be utOised in this way. Kind of Foil to be Used. The most suitable kind of foil vet found for this work is the "4B foil," supplied by Messrs. Betts & Co., 1, Wharf-road, City- road, N., price \Gd. per lb. Three and one-half sheets of size 25 x 18 inches weigh 1 lb. The foil can be obtained up to 3 feet by 2 feet 6 inches in size, and no doubt still larger sheets could be got if required. The foil contains a considerable quantity of lead. Foil made df pure tin has been tried, and has failed entirely, owing to its being too- springy to be manageable. Several samples of pure lead foil have beea tried, but without success. In contact with the lead, the chromated gelatine becomes of a greenish colour, and loses its sensitiveness almost entirely. In the process above described, an immense number of variations are, of course, possible. The formula) and method here given are those which have been found to give the best results, and they may possibly be of interest to some of our members. It is in the hope that this will be the case that I have obtained permission from tiie military authorities to read this short paper before the Society. [Captain Mantell remarked that the degree of fineness of grain 408 THE BRITISH JOORNAL OF PHOTOGRAPHY. [June .'30, 1893 might Ve regulated by the thickness of the gelatine solution employed, and he exhibited proofs showing the fine grain obtained by using a thin coat of chromated gelatine, and the coarser grain resulting from employment of a thicker coating. Referring to the end of paragraph D of the paper, he said it sometimes happened that the transfer paper adhered to the tin-foil, but he believed that difficulty had now been surmounted. He explained that the present communication was adapted from an official report which he recently had occasion to make to the military authorities on the subject of the experiments, ■which were 'being continued for certain military purposes.] Captain A. M. Mantell, R.E. A RAPID TONING BATH FOR GELATINO-CHLORIDE PAPER. London and Provincial PhotograpMc Association. liAST year I had the pleasure of bringing before yournotice an exceed- ingly rapid and simple method of toning gelatino-chloride prints, by nsing a much more concentrated solution than usual. At the time I was seeking rapidity of action merely, and, as the means necessary proved to be of the" utmost simplicity, that point was added also. IJpon the question of the resulting tone, I also claimed an approach to platinotype, and, though my results then fully bore out the claim, I Jhink it would be wiser now to describe the tone as of a neutral nature, neither too warm nor too cold, but ranging between the warmth of ft silver print and the coldness of a platinum or bromide. But the matter of tone altogether is so much a matter of taste, that it would be better to merely put the one obtained by my experiments as the result, without claiming anything for it. Complaints were made that the workers could not get warm, brown, and red tones •with jt, which caused me to wax wroth at the idiots who used a bath specially devised for cold tones, with the idea of getting warm, and then thought the bath no use in consequence. Therefore, for the present, I claim the following points as the features of my method of ioning : — 1, Great speed of action ; 2, absolute simplicity ; 3, no trouble to work. The idea has often occurred to me that we are sometimes too hasty in accusing a man of being old-fashioned and stick-in-the-mud, Jiecause he prefers old methods and won't change, as we, perhaps, have done, to newer ones. The point is often overlooked that the new method, however excellent in many directions, may yet lack any improvement in the particular one appreciated by the older worker. The above bath is an illustration, and one no doubt applicable to many workers. If rapid work and simplicity be to them no attraction, then it cannot be expected that they will forsake an old friend which perchance gives them a tone they like better. To make a personal application of this thought, I should hardly be attracted by any toning bath that was no improvement upon mine as regards speed and simplicity. Our pet ideas govern our thoughts and wishes to a greater degree than we imagine or would be willing to allow. It therefore matters but little how vast the improvement be ; if it is not in our own direction, we perhaps prefer to stick in the old groove. All my experiments have been made with the direct object of ebtainirg speed in toning. This I have decidedly accomplished, as I shall prove to you later on. But only those who have left the beaten track of toning baths for that of experiment know the great variety of tones obtainable — or, rather, obtained — for they are not always obtainable ; at least, it is difficult to ensure the same tone again, and I have settled down into the conviction that batches of paper must vary considera,bly. With exactly the same bath, and under precisely similar conditions, different tones are obtained. I have practically tested this by using four pieces six months, four months, and two months old, and a piece bought the day before. These, when toned together in the same bath, have not resulted in the same tone. It may be that some gradual chemical action takes place in the emulsion upon the paper in the com-se of storage. I am convinced that it is apt atmospheric influence at all, because I have carefully stored pieces nine months, and then exposed to air for a week in a dark comer pieces of absolutely new paper. The result was that the new paper did show traces of the treatment, but the old did not. It IS therefore either a difference in the emulsion or a chemical action Airing storage. _ The range of tones obtainable upon gelatino-chloride paper is simply marvellous. The fact strikes the experimenter most power- fully. Upon many occasions the results have caused me to use language which was quite warranted by the exigencies of the case, and was good English, but quite unfit for publication. The density ol the negative, its colour, the length of time printinar, and even the degree of washing before toning, all had a hand in the tone. How- ever, as tone is to me at present a secondary matter, we will dip at once into actual experiment. I fully intended last year, during the autumn, making a complete attack upon the question of rapid toning, but business did not permit, nor, for various reasons, have I been able to do much till lately. Even now, living in chambers, the opportunities end conveniences of work are most limited. Still I have convinced myself of several points. When I first introduced the bath, the extremely rapid action seemed likely to be a boon; but, when scant attention to it followed, it not being even thought worthy of insertion in the annals of pro- gress published at the end of the year, it struck me that perhaps there wasn't very much in it, after all, and for months, though using it exclusively myself, the subject did not bother my head. Recently, however, occasion arose, after three or four months' complete absence from any printing work at all, that batches of 100 to 1.'50 prints every night were necessary. The same bath was used, and the fact that it was a good thing came most forcibly to my mind. I determined to experiment further, and the present paper is the result. The experiments were all made with two main objects — rapidity of toning and finality of result, leaving the resulting tone to be the un- known factor. The principles laid down were : — 1. Each print must tone completely in two minutes as a maximum. 3. There must be a definite tone (finality) which no reasonable amount of after-immersion can alter. The reason of the first is obvious. By the second, I wanted to get the power of what may be termed " careless work," that is, that, if the print be unevenly toned, it can be put right afterwards. As a matter of fact, my first point in starting a batch is to see that they will readily tone unequally. Two kinds of paper, " Solio " and " P. O. P.," the former in white and pink tints only, owing to inability to obtain the mauve ; and the latter in all three. Prints from the same negative were toned in the four following baths : — - Bicarbonate Bath. Gold 1 grain. Bicarbonate of soda -o grains. Water 1| ounce. Acetate Bath. Gold 1 grain. Acetate soda 20 grains. Water IJ ounce. Phosphate Bath. Gold 1 grain. Phosphate soda 2.5 grains. Water I^ ounce. Borax Bath. Gold chloride 1 grain. Borax 40 gi-ains. Water I5 ounce. All these baths worked rapidly enough, but the acetate one re- quires mixing at least an hour before use, whereas the others can be made up immediately. The first result arrived at is, that the tint of the paper governed the tone more than any differences in the bath. I will detail the actual results : — Pink paper (P.O.P.) .... No difference in tone at all. White „ , The acetate bath gave a slightly redder tone ; the rest, alike. Mauve „ „ .... No difference. Pink „ (Solio) .... No difference. White „ „ .... Bicarbonate, grey black ; phos- phate, a warmer tint; borax, warmer still ; and acetate, quite a purplish pink. Upon the whole, the best results were obtained upon white Solio, mauve P.O.P., and white P.O.P. The latter, with the bicarbonate and borax baths, gives a tone very closely approaching that often obtained in platinum toning, viz., a very warm sepia. As a general rule, white paper should always be used if a grey black tone be desired. Leaving, now, the question of tone altogether, to deal with rapidity of action, there is not much to choose between bicarbonate, phos- phate, and acetate. But I certainly prefer the bicarbonate bath as the best of these four at all events. Mixtures I did not try, as I was aiming at simplicity. The less mixtures in photograpliic formulas the June ao, 1893] THE BUmSH JOURNAL OK PHOTOGRAPHY, 400 better is my maxim ; and, certainly, in toning batbs for ffelntino- •chloride pai)eM we can do with a littl'o more simplicity. Some of the •concoctions put forward are a credit to the inj^nuity of the chemist, viz., the number of ingredients possible to be put in without injury. They are .simply preposterous. You will see inter on that my assertions as to the speed of toning •will be borne out by the demonstration. I noted down the other nig-ht the time occupied by a batch. A whole-plate tray was used, and the following bath : — " Bicarbonate of soda ] ^ drachms. Chloride of gold 4 grains. Water (i ounces. The prints were merely laid in the tray and kept under the solution by touching with the lingers; the tray "itself wa.s never moved. Until the last few prints it took all my time to get them in and out fait ■enough. Even then I lost time by having to light my pipe. Total toned lOo quarter plates. Full time 28 minutes. First print 23 seconds. Last print 70 „ l>ne that occupied about forty seconds to tone was left for nearly an hour in the bath, and the resulting tone was no different. If we" say fifty minutes, that means a period of time which may be roughly stated as twenty-tivo to one. The print was certainly flattened or bleached a little, but the tone was not different. This jfroves that my claim to a finality of tone is quite within reason. By this means the power of what I have termed " careless" toning is acquired. A print can be half toned, the other half not touching the solution at all, laid aside for a time, and then finished. There will be no mark apparent. Or spots and streaks can be dealt with in the same way. Of course, I in no way advocate such treatment, nor that prints should be toned for fifty minutes when forty seconds will suthce. These are merely extreme experiments, but they serve to show how easy this method of work renders the toning of gelatlnu-chloride paper, which it must be admitted in some toning hatha is certainly not the esse. There is one point worth reference, which is that the actual amount of bicarbonate of soda in the bath is not, within limits of course, a matter of much importance. At least experiments with three-quarter drachm to two and a half drachm, the gold and water remaining the same have not produced any different results. The only thins.- 1 can fancy to have noticed is that the more bicarbonate the slower the toning and the greater tendency towards warmth of tone. But one and a half drachms is a fair workable proportion. The mere relation of the advantages of the bath impresses no one. Every one fails to grasp its advantages to a considerable extent; but, when shown it in actual work, it is altogether different. For that reason I shall proceed to demonstrate it before you to-night, and in doing 60 will work completely in my usual fashion. _ I claim for the bath that it is the most rapid in action and most simple in working of any one ever introduced, and the resulting tone is to me and to many others a pleasing one. W. D. Wklford. ♦ DODGES. [North Middlesex Photograpliic Society.] The subject of "Dodges " is one that should be of great interest to the amateur photographer ; in fact, it goes a long way to complete his photo- graphic education. To the profession I presume it is impossible to mention anything under this head that is not in their every-day practice ; but the beginner in the art regards anything outside the elementary instructions of procedure as dodges — at least, I do. That the best workers among us indulge in dodging is admitted. One will toll you he is obliged to dodge all his negatives, another that good negatives are the exception ■with him rather than the rule, or another tliat he has no good negatives, mostly failures, and so on. Of course, a good deal of this is modesty ; but it leads one to the conclusion that the production of superior work is, as of course it must be, the result of careful manipulation at every stage of the process, and knowing the means by which to avoid or overcome defects of every description as they arise, and to many of us they arise often enough. It is my intention, therefore, with your permission, to refer to a few rough-and-ready dodges that in my own limited practice of photography have been found useful, and I will also offer you a sugges- tion or two which I trust will be worthy of your consideration ; but I would add, that my remarks (coming as they do fcom rather a raw recruit) are intended for the less-advanced workers chiefly. The most interesting part of dodging refers, no doubt, to work on the negative ; but before we come to that I pnrpose mentioning a few other items, and will commence with development, and thence of a brush. I first saw a brush used in this room for the purpose, as I understood, of preventing air-bells and keeping the developer in motion. I tried it for the latter purpose, and soon accustomed myself to use it in literally painting out under-exposed parts (after pouring off the developer), and by this method worked up detail in the weak parts without causing uiidae density in the high lights— to me a most important point. With u-ual development, when a plate was any way underexposed, or the contrasts great, I was always liable to get the high lights developed right through to the back of the plates (when they begin to spread and cause halation) before sufficient detail was obtained in the shadows. On the other hand, with a brush, when I find the high lights progressing favourably, I pour off the developer and work out all detail, then pour on_the whole of developer again, rocking the dish until sufficient density is obtained, and stopping development when the high lights are quite through the plate and before they have time to spread. The negative I pass round for your inspection was produced in this way. The white garments of the cricketers and tent came up at once, and were fully out when the lower part of the plate was bare ; the black coat in central figure was also bare glass without detail ; but by pouring off developer except a small quantity, and tilting the tray so that the developer only covered the bottom part, with the brush I was enabled to get out all detail of grass and black coat without losing detail in the highjlights. With the ordinary mode of development I think the result would have been far different. As a curiosity, I also show you another negative of the same subject, worked up in the same way, but over-exposed, the exposure being in the propor- tion of three to seven ; the developer was, of course, very different. You will notice there is ;a difference in colourjof the film, but the printing quality is the same, and in this case I think the developer has modified the action of exposure, for I doubt if you^ can tell which is the over- exposed plate. I also pass round two other negatives, exposed and developed with the idea thatidevelopment with the brush will go a long way to prevent halation. In the first the distance came up at once, but the near buildings were certainly under-exposed, being in heavy shadow. It took twenty minutes to get out detail ; but the distance or central part was only a minute or so under the developer, irregularity being avoided by occasionally sweeping the wet brush over thejwhole of the plate. The other negative was an instantaneous exposure, treated in the same way ; but you may observe that the edges of thejtrees are perfectly sharp, and the negative with a little other dodging gives a fair print. Another advantage of the brush and local development is that clouds can be saved in the negative if there are any in the landscape ; or, in other cases, it may be desirable to keep the sky thin, and work clouds on the back in the manner to be presently described, and I feel confident, after twelve months' trial, that the brush'gives great power over the quality of the negative, and I mention it to you as a most useful dodge. Before I leave development, I would also mention the use of the warm finger in more energetically bringing out particular parts. In lantern slides this is very useful, but it' can' be [easily overdone. Gently move the second finger over the i)art you wishj.to bring out stronger. When the second finger gets cold, use the third finger on the place, and, by the time the third is'cold, the second will be again warm enough to continue the operation, and so on until the desired effect is obtained. Intensification is, I think, almost outside our subject, especially as the matter has been so ably dealt with on other occasions. I am tempted, however, to say my own opinion is that, if thin negatives are cases of vexation, intensification, unless performed with great judgment, is, nine times out of ten, quite as bad ; but there is a dodge or two in connexion with it worth mentioning. The first is, dry your negatives quickly and in a strong light ; it gives (or prevents them losing) density. You wUl be surprised at the difference in a negative dried in a strong light, or even in the sun, if the negative has previously passed through the alum bath, and one dried in the dark in a cold- situation. The first will be of a rich brown colour, the other of a greyish tone, and of less printing density. Another dodge is slight intensification by the clearing bath, but it must be a clearing bath containing uron. The iron immediately changes the colour of the film, darkens the high lights, and at the same time clears the shadows, and so gives a crispness not possessed by the negatives before. A weak solution of plain iron, or the usual u:on developer, will also intensify by changing the colour of the film. In some instances it becomes a necessity to reduce parts of a negative. a strong light through the branches of trees, or a bright ray of light through a window, or an archway, generally causes halation, to the detriment o£ the negative. In most of these cases it is possible to con- 410 THE BRITISH JOUK^^AL OF PHOTOGRAPHY. [June 30, 1893 sidcrably modify the evil, or even entirely overcome it, by chemical or mechanical means. I recommend methylated spirit (it must be neat, not s.jirit and water), and must be used, after the negative is dry, by applying a little to the part to be treated until it softens (don't be in a hurry about it) ; then, with a piece of chamois leather, rub the part until it comes off on the leather, changing the leather when it gets black, and continue until the desired effect is obtained. I only recommend this treatment for small patches, say, not excee.ling the size of a sixpence. For larger surfaces the remedy is often worse than the disease, as the result often appears unpleasantly smeary. It is effective on faces when too dense, also to bring details out in the folds of a white dress ; but, like all remedies of this description, it must be used with caution and patience. Another method I have tried, rubbing down with brickdust, and find it effective on thick films. The way to use it is to rub your finger on a piece of bath brick until the ribs on the skin are worn down, and the finger quite smooth. The finger will then have adhering to it suflScient of the fine dust to reduce density on the face, &c. This will not do for thin films. It is sometimes desirable to use quaiter-plates in a half-plate dark slide, but it is a, nuisance bothering with quarter-plate carriers in addition to being obliged to get a separate box of plates. Both of these troubles can ba avoided by cutting a half-plate in half with one of the cheap glass cutters. Place one half in centre of dark slide, filling up the side spaces with cardboard the same thickness as plate. In this way two quarter- p'.ates can be used back to back, or one quarter-plate and one half-plate. (To he continued.) C. 0. Gregory. SUMMER NOVELTIES IN APPAR-iTUS, &c. Walter Griffiths & Co., Union-passage, Birmingham, In the Zodiac camera of Messrs. Walter Griffiths & Co., which, they say, signalises their entry into the manufacture of general photographic apparatus, the substitution of metal, and that in a tubular form, for several parts usually made of wood, is not only calculated to make the camera of peculiar service in trying climates, but does so without adding to the average weight— indeed, it is claimed that it actually reduces it. The first cut shows a front view of the camera, with rising front and ex- tending base. The camera has either a leather or a cloth bellows, and all the usual movements, long extension being obtained by means of the screw which, it will be observed, runs the whole length of the base. There is no woodwork where the joints can open, the few wooden parts that are re- tained being bound with brass. The double slides are entirely of metal, and, besides being only an eighth of an inch larger than the plate, are only three-eighths of an inch thick. They carry films as well as plates. Placed in the camera, they drop into the recess from the back, and are held in position by spring clips. The construction of the slide is of the simplest, it consisting, in brief, of a species of double sheath, with two shutters. The second illustration shows the method of fixing the camera to the stand ; head, screw, and loose parts thus being obviated. Th9 camera, when folded up, is very compact. A stereo camera of the Zodiac type is also supplied by Messrs. Griffiths. Espacially in such climates where wood is liable to be affected, the substitution of tubular metal will probably be found an advantage. Upon their premises in Union-passage Messrs. Griffiths place a studio, dark room, and reading room at the disposal of amateurs. Miller's new Adelphi hand camera, which was shown us by Mr. F. V. Lloyd, of South John-street, Liverpool, has now a simple but ingenious attachment in the shape of a movemant which both releases the shutter and elevates the flap that intervenes between the senaitiva plate and the lens. This is a very happy idea. The Thornton-Pickard Manufacturing Company, Altrinchaji. The recently erected works of the Thornton-Pickard Company at Altrincham, near Manchester, which are chiefly devoted to the manufac- ture of the famous shutters with which the name of the firm is identified, are in all senses interesting, not only from their extent and completeness, but as showing the great amount of ingenuity and skill which has to be specialised and concentrated upon the produi tioii of tae r rm's specialities. The workshops, as indeed the premises generiliy, ar- situated entirely on the ground floor, and in the first-named, which radiate, as it were, from the office as a. base, it is instructive to follow the growth of a shutter in the various hands tlirough which it has to pass. Under the guidance of Mr. Edgar Pickard, such an opportunity was recently given us. The preparation of the mahogany boxes in which the mechanism and blind of the shutter are contained is first noticed. The parts are glued up under pressure, and the boxes as made are double, and are therefore split into two. A sand-papering machine imparts the necessary finish to them, the particles of mahogany dust created by the revolving stones being carried off by fans. For the wood in the rough a planing machine working at 5000 revolutions a minute is used. Passing by several circular saws for light and heavy work, we stop to watch a workman pressing the little indicator wheels out of sheets of brass; an upright moulding machine for ronnding off the corners of the boxes, and a cutting machine for turning out the small connexions for connecting tubing to the shutters. Other machines are devoted to polishing the pins of the shutter, turning, holes in the shutter cases, etc., the machinery being driven by a seven horse-power Otto gas engine. In one corner a lad is at work at a sewing- machine preparing the blinds. One side of the workshop is practically devoted to lacquering and blacking the various parts and the fitting together of the shutter. The spring of each shutter is tested by a weight before it leaves tlie shop for the testing department. A separate shop is devoted to the polishing; and in the stock-room, behind a series of carefully "blinded" divisions.'stock June 30, 18U3] THE BRITISH JOUKNAL OF PHOTOGRAPHY. 411 of the numerons parts is kept. Taking a line by the enormous numbers of each individual part — such as the indicators — which wo saw in pre- paration, one is driven to the conclnaion that the output of the Thorntcn- Pickard Jshuttora is very largo. This rapid and imperfect sketch of the firm's workshops does not in any way do justice to one of the completest and most interesting installations in connexion with photographic in- dustry which we have recently inspected. Since its first introduction, the well-known Time and Instantaneous shutter has undergone some slight modifications, although its action and principles remain the same. Among recent additions is a speed indi- cator, which consists of a dial, marked in fractions of a second, attached to the side of the shutter, and a pointer on the end of the spring-roller spindle. The speed is indicated on the dial in fractions of a second by the pointer, which can be set to the speed desired by means of the nob. A similar type of shutter, the " Snap Shot," is very popular for hand cameras. The Focal Plane shutter is designed for use where the maximum degree of rapidity is required. It is made upon the roUer- bUnd principle. It fits into the back of the camera in the place otherwise occupied by the dark slide, the dark slide itself being placed in the baqk of the shutter. The shutter blind, therefore, works just in front of the plate, and has a narrow slit in it the tall width of the plate, which gives the exposure as it passes rapidly across. The speed is regulated by the small knob. The shutter is set for exposure by winding the large knob at the top, and to show how far to wind there is a winding indicator at the opposite side, not shown in the engraving. In the bottom end of the blind there is an opening the full size of the plate, by means of which the picture may be focussed on the ground glass if the blind is wound to the top. A new patent adjustable slit is now added to the focal plane shutters in addition to the adjustable spring roller. This improvement adds greatly to the range of speed of the shutter, which now extends from one-twentieth of a second to one one-thousandth of a second. The speed is varied by means of a chain at each end of the slit, which can be lengthened and shortened at will, making the sides of the slit perfectly parallel without skill, the directions for use being as follows : — After removing the focussing screen, take hold of the two struts which form the parallel sides of the slit in the blind, and turn them askew, at the same time drawing them forwards out of the shutter. The chains at the ends of the slit can then be manipulated. One end of the chain is fixed permanently to one strut, while the other part of the chain is linked on to the extreme end of the other strut, the end of it passing inwards along the length of the strut. This part may be pulled out and linked on to the end of the strut to make the slit wider, or allowed to spring back into the strut which makes the slit narrower. All that is neces sary is to see that the same number of links are used at each end of the slit. The speed of the shutter is found by dividing the speed given on the indicator by the number of links in use at each end. That is to say, with only one whole link the speed is that given on the indicator ; with ten links (which is the extremity) it is one-tenth of the same. The safety blmd which Messrs. Thornton-PIckard fit either to the Time and Instantaneous, or the snap-shot shutters, when fitted to the shatter, will automatically cover the opening during the act of resetting the shutter for the next exposure, 60 that the sensitive plate may always remain uncovered in the camera. It only adds five-eighths of an inch to the thickness of the shutter, and does not increase the dimensions otherwise. The illustration shows a section of safety blind attached to an ordinary shutter, either Time and Instantaneous or snap-shot pattern. In action, when the tassel is pulled, the exposing blind D is wound on to the top roller A, by means of the cord C, and at the same time the sifett' blind K is pulled up over the top roller M by the cord N. It will be seen from the illustration that the safety blind K, and the opening H in the "^ ' exposing blind, both pass across the aperture in the shi.'.ter together, so that no light can pass throu -'h. When the K9T SUfOStO tassel ii released, after palling the cordi as far as pcsaible, the safety blind immediately rewinds on to the spring roller Q, leaving the ezposiiig blind set ready for exposure. The annexed llustration shows a small and useful device for enabling one to see at a glance which plates have been exposed, thus preventing the possibility of two pictures being taken on one plate. It consists of a small hinged plate or lid, which lies down fiat before exposure, bat, as soon as the shutter of the slide is withdrawn to expose the plate, the lid files open and discloses the word " Exposed," and remains in this position until the slide is again charged with a fresh plate in the dark room. The " Becorder " may then be set ready for the next exposure by simply closing down the lid with the forefinger, at the same time closing the shatter of the dark slide. Whenever the shutter of the slide is withdrawn without exposing the plate, the "Becorder" lid may be closed again at the same time the shutter is pushed home. The " Euby " camera is an exceedingly light, rigid, and portable instrument, fitted with a turntable, the centre of the latter being cat away so that the lens and shutter fold up with the camera. The front can be quickly erected, and is rigid and firm when in position. The cut shows how to fix it. After opening the camera, place the front in the position shown, leaning backwards, so that the bottom corner hooks of the front are over the pivots marked P. Press the front down between the pivots, and then place it in the vertical position, as shown in the figore. Fasten in position by turning the winged clamping screws marked W. The camera has double pinion for focussing ; it allows of the use of very wide-angle lenses, rising and sliding front, and all the other usual move- ments, obtainable with a minimum of trouble. In the way of tripods the firm have very recently brought oat a stand having automatically locking joints, which, while being perfectly rigid, is easily set up, and is adjustable to various heights. The lower section slides so as to be adjustable in height. On paUing out this section as far as possible the spring bolt marked by the arrow in (he engraving springs out and instantly locks the oint. To close again, the spring bolt is pressed with the thumb, which allows it to slide back again. A thtunbscrew is provided at this joint, so that the section may be adjusted to any height, as above mentioned, and may be used in addition to the spring bolt to give extra rigidity if desired. The upper joint is locked on exactly the same principle, but it folds instead of slides ; the spring bolt is larger and stronger, and snaps into position as soon as the upper section is nnfolded. The two sections are 412 THE BRITISH JOURNAL OF PHOTOGRAPHY. [June 80, 1893 therefore wedged together in a very practical manner, and the utmost rigidity is secured. The rapidly increasing specialities of the firm show that a great deal of mechanical tliought and application have been expended on them. AU have a degree of finish and carefulness of construction which stamp them as the products of great skill, while of the practical efficiency of the series of shutters, and their adaptability to the needs of various classes of photography and shutter-users, there can be no doubt. The Chadwick Impkoved Hand Camera. The annexed cut was omitted from onr notice of the Chadwick hand camera last week. It shows the camera on a stand, and the swing back in use. As may be observed, the back swings from its centre, which, in theory, it should do. ©ur lEDitorial Catlt. Dr. AxDiiESF.N'"s Glycin. Arthur Sdiwartz & Co., Dasbwood HouFe, E.C. Thk directions for using Dr. Andresen's glycin are as follov^s : — I. For soft development : Solution A (warm slightly). Glycin 4 parts. Carbonate of potash ; li „ Sulphite of soda (crvst.) 12 „ Water ". 100 „ Solution B. Carbonate of potash 10 „ "Water 100 „ For use, mi.x one part of A with two parts of B. II. For hard development : Glycin 5 parts. Carbonate of potash 2-5 ,, Sulphite of soda (crvst.) 2-5 ., Water '. 100 „ For use to be diluted three times its volume. Employing the developer in accordance with the first-named formula, we find that, although it is rather slow and deliberative in action, yet it yields negatives of great harmony and softness, and of a charming colour. It is an elegant developer, likely to be of service in special cases. Bakeks Toukists' Developing Tent. Mn. C. Bakeh, of Wallington, Surrey, has modified the developing tent he brought out some time since. The illustration shows its con- struction and general appearance. The tent when open is about IM use. 26 in:;^ I2XIO CLOSE forms a box twelve inches square by three and a quarter inches, iis which there is room for several small articles. The sides of the tent are- composed of ]3erfect]y opaque material, and as the light can only enter by the red window, which is guarded by a blind, its amountcan be- regulated as desired. The tent is simple and efficacious in use, and should be popular. "PilOTOGKAPHY" ANNUAL, London ; lliffe k Sou. Mb. Henby Sturmky, the editor of this ponderous annual, may con- gratulate himself upon having this year issued a volume exceeding- both in quantity and quality any of his two former annuals. It opens- with a section devoted to reference tables, a feature that is always useful. I'ips for tyros follow. Mr. C. II. Bothamley discourses on "Progress in Photographic Chemistry during 1892,"" and Mr. A- Taylor similarly on " Progress of Astronomical Photography." There are other articles on various phases of photographic pi-actice, and quite a number of illustratioHS both of a pictorial and diagrammatic nature. Recefved : — Sixtieth Annual Report of the Royal Cornwall Poly- technic Society; The llluftrnted Archaroloyist, No. 1, edited bv J. Romilly Allen (Chas. J. Ciarli, 4, Linooln's-inn-fields, W.C). RECENT PATENTS. APPIJCATIONS FOR PATENTS. No. 12,008. — "An Improved Plate Rest for Supporting Negative or Positive- Photographic Plates in .a I''i.\lEg or other Bath." J. B.iRNEs. — Dated June 1£>, 1893. No. 12,287. — " Ira))roveincnts in Photographic Apparatus." Coramunicatecl by P. Meyer. A. J. Boult.— Dated June 22, 1893. No. 12,296. — " Improveioeiits in the Manufacture of Half-tone Gelatine Reliefs for Process Blocks." Complete specification. J. HusNiK.^Ocite/ June 2'^, 1893. No. 12,304. — "An Impiovement in the Manufacture of Sensitive Plates or Filnis for Photographic Purposes." Complete specification. F. W. Edwabds- and H. R&hsom— Dated June 22, 1893. No. 12,443. — " ImproveineBts in Photographic Apparatus." W. J^ Greatorex. — Dated June '2i, 18'.i3. SPECIFICATION PUBLISHED. 1892. No. 13,857. — " Photographic ChaBging Boxes." Newman k Guardia. ifletttKisiS Of SoctetteiS, MEETINGS OF SOCIETIES FOR NEXT WEEK. twenty-four inches long by ten inches wide and ten inches high without the sink, which is two and a half inches deep; AVhen closed, it Date oi Meeting. Jnlj 3 3 3 3 3 3 4 ■i 4 4 4 4 4 4 ... 4 4 4 4 5 5 5 5 5 6 0 6 6 6 6 fi 7 7 7 7 7 8 Nanio ot Society. Dundee Amnlour Ptiterborowgh Putuey Eiohmomi South Londoo StereosGopii; Clnb Birmiugham Photo, Society Brixton auU Ohipham Ezeter Hackney Hereford^ihire Lewo8 North Loutlon Oxford Photo. Society Paisley Rochester Rothorham Sheffield Photo. Society York LeytoDhtoue PhotogTaphic Club , SoTithport , Southsea , Wallasey Birmingham Photo. Society GlosKop Dale Hull Leeda Photo. Society_ Loudon and ProTincial Oldham Tnnbridgo WcUb Cardiff Oroydou MioroBOopical Holborn Leamlni^toa Maidftono Hnil '. PlAce of Meeting. Abso. Studio, Nethergato, Dundee* Museum, Minster Precincts. High-stroot, Putney. Greyhouud Hotel. Hanover Hall, Hanover-park, S,E, Brooklauds Hotel, Brooklands. Club Room, Colonnade Hotel. 376, Coldharbour-lane, Brixton. City Chambers, Gandy-st,, Exeter. 20G, Mare-streot, Hackney. Mansion House, Hereford, Fitzroy Library, High-st., Lewes. Canonbnry Tower, Islington, N. Society's Rooms, 136, High-street. 9, Gauze-street, Paisley. Mathematical School, Rochester. 5, Frederick-street, Rothorham. Masonic Hall, Surrey-street. Victoria Hall, Goodramgate, York. The Asseml^ Rooms, High-road. Anderton'a Hotel, Fleet-street, E.C, The Studio, 15, Cambridge-arcade^ 3, King*8-road, Southsea. Egremont Institute, Egremont. Club Room, Colonnade Hotel. 71, Prospect-street, Hull. Mechanics' Institute, Leeds. Champion Hotel, 15, AJdersgate-at-- The Lyceum, Dnion-st., Oldham. Mechanics* Inst., Tnnbridge Wells.. Public Hall, George-street, Croydoci Trinity Church Room, Morton-at " The Palace," Maidstone. 71 Prospect-street, HolL June 00,1693] THE BRITISH JOCKNAL OF PHOTOGRAPHY. 418 PHOTOGRAPHIC SOCIETY OP GKEAT BRITAIN. ! . NE i7,— Mr. G. Soamell in the chair. Mr. W. E. Ueeenham gnvo a, demon.itmtion of Tlic Carbon Process, pre- i.vjiug it with .% brief ilescription of its essential principles. Speaking of the sensitising of the tissue, he said he preferred to use the bichromate in the pro- portion 01 one ounce to a (juart of water. He found no advantage in the addi- tion of aiiiniouia, except when an excess of chromic acid is present. In diying, he recoinnieuded squeegeeing the sensitised tissue on to tlie glass, and leaving it thereon until it is wanted, as if dried by hanging the tendency to curl was objectionable. Having dealt with the uses of the safe edge, and demonstrated both single and double transfer, he said that for exposure he preferred the actiuomcter he himself devised some years ago, and which was .•ulopted by the late Mr. Sawyer. He, however, used a portion of a portrait negative, various tints from which were made on gelatine or albumen paper, and could be matched in printing. In development, if the print was too dark, hotter water could be used. A brief discussion followed on the continuating action of light. Mr. H. J. BuBTON remarked that, in the print developed, which was said to have been ovcr-priuted, the continuating action had taken place. There was plenty of time since the afternoon, when Mr. Debenham had made the print. Mr. T. BoL.vs agreed with Mr. Burton, and said that, if a trace of damp was present in the tissue, the effect of keeping the exposed tissue a little while in a hot place was easily recognisable. Mr. H. C'HAP.MAX JoxEs, when exposing tissue to be kept a day, would only give it a quarter of the time as against the full time when exposing and developing the same day. After other discussion, a vote of thanks was passed to Mr. Debenham, and the meeting closed. LONDON AND PROVINCIAL PHOTOGRAPHIC ASSOCIATION. J f.NE 22,— Mr. W. E. Debenham in the chair. Mr. \V. D. Welford passed round the catalogue of the exhibition of photo- graphs recently held in Japan, also two books of pictures by Mr. W. K. Burton of snapshots and enlargements in collotype. The Universal Hand Cuiera. Mr. H. B. Sharp (Messrs. Sharp & Hitchmoiigh, Liverpool) exhibited and explained the Universal hand camera. This is a quarter-plate camera con- tained in a box, the back and front of which let down, or the camera may be entirely removed from it. Focussing is effected by means of a rack and pinion attached to the body, thus rendering the camera useful for co]iying and lautern-slide making where it is desired not to move the lens. The camera iias swing back and rising front, time and instantaneous shutter. An I.MPBOVED Ketoochixo Desk. Mr. Sharp also showed a retouching desk having a spring, .attached to which was a diaphragm, with inner diaphragms, for ]>lacing round the head or any part of a negative, and thus coucentnating the light upon it. Chamois leather on the diaphragms protects the negative. At the side of the frame a small glass is let in, which is illuminated by the same light as the neg.ative, and is used for matching tints. " Welford's Toniso Bath fob Gelatejb Prints." Mr. W. D. Welkord read a paper on this subject [see p. 40S], afterwards toning several prints by the bath. Toning was completed in less than a minute. Prints the halves of which were toned at intervals gave no indication of "joins." Untoned patches subsequently toned were indistinguishable from the parts tirst toned. In the discussion which followed, Mr. T. BoLAS observed thiit he preferred a more thorough washing between the fixing and the alum solution than Mr. Welford gave. , Mr. J. S. Teape tried the bath last year, and found that, after toning a dozen prints, the others had a certain tendency to mealiness, and finally they lost quality altogether. He used the same batch of paper tliroughout, and noticed that many of the prints had a tendency to pinkiness. Mr. T. E. Freshwater had succeeded well with an acetate bath for gelatine paper. The latter seemed to require much more careful washmg than albumenised paper. The bath, which was supposed to be kept twenty-four hours after being made, and which he had used at once, was as follows : — Acetate soda 1 ounce. Gold chloride lo grains. Water 20 ounces. Of this stock solution he had used two ounces in eight ounces water. Mr. P. Everitt thought the rapidity of action of Mr. Welford's bath might be a disadvantage to many ; he himself would not care to use a bath that toneil so quickly. If one wanted a variety of tone, there would be a consider- able difficulty in obtaining it with a very quick toning bath. He himself used one and a half grains of gold chloride in twelve ounces of water, to which a pinch of borax was addetl. Mr. A. Haudos asked if Mr. Welford had noticed any difference of result between carbonate and bicarbonate of soda. Mr. J. Weir Brown pointed out that the tones of some experimental prints Khowu were not the same as those of some prints which Mr. Welford had made with the bath last ye.ar. Mr. S. Herbert Fry thought it a misfortune that Mr. Welford should advocate such a process, as the double colour in the prints was most detestable. It appeared to him that the bath had no other advantage but rapidity, and the fact that it toned so quickly proved that one h.id no control over it. The colours that one saw with the gelatino-chloride process were very nice, but he W.1S inclined to think there were other processes which yieldeosure. The Chairman then showed and explained a Wynne's exposure meter. It appeared to him to be a very good and cheap article, and he said he would try and report further on it. Mr. Penny showed two negatives. One had been enlarged by the cresco-fylma method, and the other by using hydrochloric acid two draclims to four ounces of water. The result was precisely the same. Owing to the unavoidable absence of Mr. Hensler, Mr. Gosling started a discussion on Toning. He was in favour of plenty of gold, and the use of the sulpho- cyanide bath, for P. 0. P. Mr. NuNN said he had obtained yellow tones when using borax. Mr. Barnes used a lead toning Imth, but the colour w.is too slaty. The Chairman said he had read tliat chloride of ahmiinium was recom- mended in place of alum to hanlen the gelatine in the prints, the great recommendation being that they could be the more readily handled without injury. Brixton and Clipham Camera Club.— June 20.— Mr. C. Gowlwin Norton gave a demonstration on Phctoiira^hy hy Arliricial Light. He advocated the use of five or six blow-through jets arranged in a cluster, and enclosed in a box, in front of which a tissue or prepared calico screen should be stretched. The exposure averages from eight to twelve seconds, and the results are very good. The average cost per sitter is about threepence for the limes and com- liressed oxygen. Reflectors of some white material will be necessary in order to lighten the shadows a little. The light should be suspended from the ceiling of the room by a coriacticc to dtuceiid to the level (■/ ci shiipkeejnr." The italics are mine. Now, I would be glad if •' Pioneer" would point out wherein consirts the degradation of a shopkeeper as compared with any other member of society, not excepting even the aristocratic professors ut photography. I take it that, whatever occupation a man follows, if he does liis duty and conducts himself in a becoming manner, he is worthy of our respect and admiration, and I fail to see what there is in the business of photo- graphy to make a photographer such a very superior person, so far above the level of a shopkeeper. "Pioneer" should have lived in the middle ag-s, when wealth and power, class and lineage, were the chief factors in giving a man a status amongst his contemporaries ; but in the nineteenth century people are a little more enlightened, and honour a man for what he is, and for what he makes himself by his conduct and abilities. I would be the last to cast a slur on the business — call it profession if you like it better— of photography, and 1 consider I do it no dishonour if I place it on the same level as shopkeeping. There is far too much nonsense talked of the status of the profession of photography, and it is time the " low shopkeepers " had an innings. It is also entire nonsense to talk of Excise licenses or Acts of Parlia- ment helping to give a status to photography, and limiting the number of photographers. An ordinary hawker has to have a license, but that does not make him a superior or inferior person more that he was before. Ills character that tells. Photography in these days is easily acquired by one year's careful study and practice, and those who are so contemptuously referred to as shopkeepers often beat, by their amateur productions, the work of a lot of professional photographers. So long as professional photographers can turn out superior work, they have no need to fear amateur compe- tition, and " Pioneer" should remember that in this world everything is governed by natural laws, and when artificial law clashes with natural law its efforts are useless. 1 have a large amount of sympathy for those professional photogi'aphers who cannot make their business pay. Here natural law comes in — the supply exceeds the demand. They must, therefore, turn their hands to some other work. And we must remember that if the amateur does injury to the professional, he does a large amount of good to photo- graphic manufactureis and dealers; therefore, those who cannot make_ a living as professional photographers should take heed of the signs of the times, and make a living by catering for the increasing army of amateurs. It is merely diverting trade into another channel. Ko honest work or business can possibly be degrading to any man, but idleness is most reprehensible, and so is pride of class. — I am, yours, &c., William James Farmer. 68, Blackburn-street, London-road, Blackhiini, June 20, 18'i)3. PHOTOGRAPHIC CONVENTION OF THE UNITED KINGDOM. To the Editor. Sir,— It may interest those of your readers who intend attending the Convention to know that the Great Western Hallway issue third-class excursion return tickets to Plymouth for 2U. by the trains leaving Pad- dington on Saturday, July 1st, at 7.55 a.m. and 1.55 p.m. Passengers can return on the following Saturday, Monday week, Saturday week, or Monday fortnight. Times of return trains on Saturdays and Mondays, 8 a.m. and 12.30 p.m. — I am, yours, Ac, 10, Cambridge-Hardens, F. P. Cemeb.vno, Jcn., Hon. See. liichmond, S.ir. • DE\'ELOPMENT OF OVER-EXPOSED PLATES. To the Editor. Sir,— Many readers of The British Journal of Photography for June 2, 1803, p. 251, and those of Photographic Scraps for this month, must have been greatly interested in the record there given of Prof. W. K. Burton's experiments respecting the successful development of greatly over-exposed gelatine plates, and will be looking forward to the time when full details of his system of treating such long exposures are pub- lished in the photographic journals. I understand that he will read, or send to be read, a paper on this subject to the Photographic Convention for 1893, which will give full details of his method, no doubt, which will greatly assist any one who is interested in this important matter, for the speed of the gelatine dry plates is being increased by some maker or another almost every week, which, of course, will tend to favour over- exposure greatly ; therefore a reliable method of overcoming it will, or should, be welcome to all photographers. Judging from a description I read a short time ago, the new develop- ing agent known as " Glycin-Hauff " appears specially adapted for the successful development of greatly over-exposed gelatine plates. It may also interest many readers to know that a saccessful method of develop- ng both iinder-txpiiied and orrr-crpoted gelatine platen was published in TuK British Journal of I'lioKMinAPHv for May 29, 1H8.5, pp. 842 and Siii. also in the Almanac of the same Jocbnal for 1887, pp. 197 to 199 ; in the latter, additional details were given. The developer used waapyio, bromide, and ammon'a. I have tried the formula given there for under- exposure, and found it work well, and have no doubt but what thote recommended by the writer of the article referred to, Mr. F. P. Leon, would be found equally satisfactory. He said the formulic he gave suited all the gelatine plates then upon the market, theretoie ii is very probable that they would be equally successful if tried at the present day ; indeed, I intend to do so at the earliest possible uiomeiit, and may send you a report of my success, or otherwiuc, for publication, should you be able 1o spare space for it. — 1 am, yours, Vc, J. j. Hacketi. Fleet, Hauls. iEictangc (ZToIumn. •»* iVo charge is made Jot inserting Exchanges of Apparatiis in this cohimn ; but none vnll he inserted unless the article wanted is definitely stated. Those who specify their requirements as "'anything us'faC will therejore understand the reason of their non-appearance. The full name of the advertiser must in all cases be given for publication^ otherwise the Exchanges will not be inserted^ Will exchange I2s. 6l1. set of Xameit (new) for r'aotogrcxihy, by A. Brothers.— Address John Weie, photographer, MoHat, X,0. WR-nted, changinBT bag; -will give Luncasler's patent foldinaf lamp in exchange. — AddiN:88, H. Ward, tne Stratford Studio, the Dulph, Bri^rrley Hill. Will exchange embossing press and four dies for cabinets and C.T>.V.'s, by Marion, cost 51. OS., for other photographic apparatus.— Address, W. Walker, lo6, >oel- street, Nottingham. Wanted, whole-plate modern camera and three dou>»le slides, in good condition, in exchange for tricvele in good coudition. Can be seen any day.— Addres?, A. Ij. Smith, 233, Uxbrjdge-road, W. Will exchange quarter-plate camera (by Talbot & Eanier), three donble book »1tde» three-fold tripod, also silver Geneva watch, tor half-plate camera, three donfal slides, and tripod. — Address, J. K. Smith, Little London, Kawdon, Leeds, Yoric^. Will exchanore a Robinson's iniarter-plate single laLdscape lens and a enryscope, /-6 quarter-plate rapid vecciliuear lens, and 5s., for a rea ly decent wbole-plate lens. — Address, Charles J. Harris, 3, Pentyre-tori ace, Sea-viow, Plymouth. Will exchange Mofs k Milton's twelve-inch enamellor, nickelled roller, perfect as new for 12x10 outdoor camera, with all movements, three double alided, tripod, «tc., posing char, or first-class backgi-ounds. — Address, Thompson, 72, Market-street, Uradtord. Will exchantre a rigid brown waterproof campra ca*e, nine and a half inches in height, eight and a half inches wide, and fourteen and a half inches long, never used, also changing bae and half -plate sliding mahog»uy tripo The glory of discovery is the reward. The love of the work is ample re- payment." That's all v.-ry well, and I believe that he who says so has perfect confidence in his statement. Yet, " What is it worth ? " is really the point to be solved on the introduction of any new thing. It may seem a very poor platform on which to place the work of the en- thusiast and the investigator, embracing as it does years of experiment and labour that on which is marked ■' What is it worth?" but I fear that with but few exceptions it comes down to that at last. There are exceptions to every rule, and all of us have met the enthusi- ast who, for the love of the thing only, goes on working untiringly in one groove or another, using both time and money for the advancement of. the art-science, anticipating no profit from his labour, the pleasure of overcoming difficulties and the joy of " finding out " being his end and aim. But, even in such a ease, what has been discovered, if to spread and flow, it must come to the river of commerce. If one happen to have- income enough so as to render his position independent of any thought of repayment, he may sneer at the position herein taken up ; but, never- theless, it is a fact that commerce is the stream into which all the- tributaries flow. Looking bock to the beginning, we find Niepce straying along the country roads trying to gather stones suitable for his photolithographic experiments ; liis correspondence with the I'aris litho- grapher and his partnership with Daguerre all have a commercial leaning. We also find his brother, who, in his own time, was as great a. scientific enthusiast as himself, determine to leave his home, and resolve to come to England, feeling sure that it was a better field for the success of his inventions. And have we not the notable cases of Daguerre and of Mr. Fox Talbot protecting their inventions? What for?' For a profit, of course I Whether we agree regarding the position I take up, that the end and. aim of all our work tends to commerce, I have no doubt we will be at one on the various items that I intend to touch upon to-night, for they are in their very essence the work of the business. And, first, I would make a few remarks upon the Convention itself and its membership. Last year was tbe most ^successful of all our meetings ; but the Con- vention meetings, since the very start, whether large or small, have ever shown great vitality. Still, the professional has not given it either the attention or the support that I feel it was his duty to do, and that the institution deserves. The greater part of the success of our meetings is due to the support, and enthusiasm of the amateur element, and why should this be? Surely there ought to be some equality of representation. The pro- fession, as a body, is large enough and influential enough to at least treble its present representation ; but I fear that it is the spirit that lacks energy and enterprise. At first there was a considerable outcry about the time the meeting was held being unsuitable for many in the profession. To meet this objection, the date has been changed two or. three limes, I think ; this with some little advantage perhaps, but not^ much. Taking professional photographers collectively, I feel that if they tried they could make this meeting for themselves the most pleasant and . profitable outing of the j'ear. Every one that has been with us- knows that this is an honest statement, and, if they would only gather round in numbers, they would find it a gain both in health and business. The lines on which our Convention is run commend themselves, and are better, in my opinion, than those adop'ed by our American friends. To a great exttnt the American Convention is a dealers' show, a good enough thing in its way, but the platform upon which we meet is more inde • July 7,1893] THE BRITISH JODRNAL OF PHOTOGRAPHY. 431 pendent, and the principal bnainess of oar gathering ig educational and social, the dealera' part heinR a mere detail, and never interfering with the more salient points for which we meet. The profeBsional who joins us in this week's outing, by personal con- tact and general interchange of ideas and experiences alone, is bound to learn more than he would in very much more time spent in less con- genial and less favourable circumstances, so that, even as a paying speculation, I look upon the Convention as a profitable investment to any member with his eyes and his ears open. Hence I would that the pro- fessionals bestir themselves, and make a fairly representative turn out. If they but did this, the institution would be, beyond doubt, an assured success for all the coming years, a centre where the representatives of all the various societies might meet in a broad union once a year. The National Association of Professional Photographers should find the time and places of the Convention a fitting opportunity for their meetings. There they could be in numbers, and could easily arrange to bold their own special meetings during the week, to suit [themselves without in any wiay interfering with the general arrangements of the Convention. All being in one town at one time, more meetings could be held, larger audiences could be got, and they would be far more likely to command Attendance than where they have to travel, in many cases, long distances for single meetings. Last year Messrs. Fall, Whitlock, and O'Neill made a move in this direction, and I have no doubt that their endeavours then tended to the growth and influence of the Society. This Association, worked on broad lines, should be a power for good to the whole profession, there are so many questions of importance, such as insurance, copyright, holidays legal defence, prices, and many other subjects that are of great com- mercial interest to the whole profession alike. One thing might here be noted : that the obtaining of a closer union between the individual members of the profession is what should be aimed at if success is to be the result in this as well as all otlier like institu- tions ; and this is the greatest difficulty to be overcome, for the photo grapher does not take so kindly to unity as most other professions do. Here I would say a few words on behalf of the Photographers' Benevolent Association. This Society should have much more consideration and sympathy from the photographic worker. On investigation, I find that most of the funds and the greater proportion of interest and work is undertaken by the kindly well-wisher, and that don't-care-about-it apathy still belongs to the working photographer. As I have elsewhere said, every employe in the photographic trade in the United Kingdom holds a special interest in this Society, and half-a-crown a year is all that is necessary to be paid up by any one to place himself in the position of membership, which, in cases of need, gives him the advantage of becoming a participator in the funds of the Society. About a halfpenny per week ! just think of it ; and for this fraction, if paid by the body of employers, the income of the Society would be raised to 400i. a year, and, if the employers also joined, the return shown could not be leas than 500/., at the very minimum, of our outlay. Look at the power for good this would place in the hands of the Executive. If every em- ployer would interest himself to induce his employes so to assist them- selves, the feat would be accomplished, for they could not fail to be successful, and thus the many rivulets would swell the greater river. For the promotion of union in the profession, I think that the institu- tion of the " Central Photographic Club" is no mean factor. It opens up an avenue of social intercourse and information, and any- thing of such a nature must help to advance a man in his business ; it gives him the opportunity of being up to date, and that is one of the essentials of successful trading. A place of meeting where, at all times, the country member comes in contact with his compatriots in the city, and where he at once gets into the centre of that which most interests liim — and the friends from the provinces will also keep the city members ac(iuainted with what is going on in the country districts — and these advantages are to be obtained at a merely nominal outlay. This Institution should have the fullest support of the profession. The Affiliation scheme of the Society of Qreat Britain is also a march in photographic progress that should help to draw photographic societies together, and, if taken up with a will, must result in an intercourse that is bound to be beneficial to all, the interchange of papers and slides alone being of great moment and importance, especially where societies are too small or too young to be able to produce new subjects or original matter without help from wider fields. The progress of the year shows steady advancement ; nothing startlingly new, but there's not a week passes without the introduction of some in- genious device or discovery which tends to save labour or to perfect results. It has been stated that there are more patents taken ont in conoezion with photogriphy than in any other trade of like dimensions, and, looking at the continuous stream of applications for protection, it is easy to believe. Printing-out papers is one phase of photographic work that has made a marked advance in the currency of the year. Uelatino-chloride paper has come into almost universal use, the beauty of the finished results se- cured by the use of this paper tending greatly to its growing popularity. Collodio-chloride paper has also grown considerably in demand, as it is considered by many to allow of a greater variety of tone, and also that it is more permanent than the gelatino-chloride, but to prove the latter re- quires the test of time. The new cold-bath-process paper introdnced by the Platmotype Company has also made a rapid stride to the front, and is now almost universally adopted. The advantage of local development by its use being rendered sure and easy was a great recommendation to its success, and, where it has been fairly tested, the hot bath baa been laid aside for this more perfected process. Stereoscopic photography, which, like the sleeping beauty, bas been lying dormant for so many years, Jives and breathes again. A great ad- vance has been made, and considerable work has been done in this de- partment during this last year, and it still goes on increasing. A big future may be anticipated for it. The hand-camera competition still runs on without impediment. The originality and ingenuity displayed and expended on the construction of these little instruments is perfectly astonishing, and the excessive number of forms placed upon the market— each professing to be the best— is marvellous. By their results ye shall know them. The work produced by them is to be found broadcast in all sorts and conditions of illustrated papers, photographic and otherwise, ranging from very bad impressions up to charming productions. So much in favour has the hand camera become, that I have no doubt but that the larger proportion of the apparatus brought for use by the members of the Convention will be fonnd of this description. If the advances daring the year have not been made by leaps and bounds, they are at least sure. In lenses, the Zeiss, the Dallmeyer Tele-photo, and the Boss Coneentrio are increasing in demand. Isochromatic plates are taking a firmer hold, and the Sandell has been adopted by many. The journalism devoted to the profession seems to be oat of all propor- tion to the extent of the trade it caters for, bat I suppose time will try them, and the weakest will go to the wall. Since last we met we have had to mourn the loss of one of our beat friends — one of the most genial and gentle of men, foremost in every good work, an able artist, and thorough experimentalist — Mr. William Bedford. I pay this tribute to his memory as one of our previoas presi- dents and the friend of all. And now I will leave the various members, in their various claaiM, daring the Convention, to thrash out their varioas themes, one by-one, scientific or chemical, each in his department, be it development, speed, light, colour, or optics, each of them needing its own specialists to do it justice. I hope you will aU spend a happy and enjoyable week. On the motion of Mr. James Martin, the President was thanked for his able address, and the Mayor for his cordial welcome. Light refreshments were then served, and the rest of the evening ■was devoted to the admirable exhibition arranged in the art gallery, and to views shown by the optical lantern. The exhibition, a fuller notice of which we will give next week, contains much that, in the estimation of the Wsaitem Morning Neies, \a a revelation for the west. Kastman has a grand and tastefully displayed exhibit illustrative of the capabilities of their Solio paper and of their Nikko paper, a de- velopment paper which may run bromide paper very hard. Morgan & Kidd have remarkable bromide enlargements (one eight feet long in one piece), and specimens of the beautiful collotype process. Mr, W. Scorer, of Havant, has two direct landscape works, 36 x 20, and two of his very ingenious cameras with double eccentric fronts. Elliott & Sons have a splendid portrait of a lady from a direct nega- tive live feet by three. Mr. E. H. Micklewood has works illustrative of his shutter for securing clouds naturally ; and Messrs. li. W. Thomas of the Sandell plate. 0. Sichel & Co. have a fine collection of moulds and mounts and elegant studio accessories, and a very complete studio camera. Byrne & Co.'s portrait of an infant Battenberg prince is one of the choicest things shown. Mr. W. t«. Tweedy sends inter- esting results of panoramic photography, and J. Martin & Co., New Soutbgate, an ice picture. There is a very neat collection of 422 THE BRITISH JOURNAL OF PHOTOGRA,PHY. [July 7, 1893 Dr. Andresen's chemicals, many of which are in handy cartridge form. Local photography is admirahly represented. Mr. Heath, of Plymouth, includes a more than life-size autotype carbon print of the Prince of Wales, from a negative taken by command during his Royal Highness's recent visit at Admiralty House, Devonport; Mr. Hawke, of Plymouth, sends a score of photographs of the Duke of Edinburgh ; Mr. R. F. Yeo, of Plymouth, has charming studies of children ; and Cox & Durrant, Torquay, send a delightful portrait in sepia. There was a lantern display at the close of the reception. Among the slides were several by Dr. Mitchell (of Philadelphia), Major Lysaght, Messrs. York, Cembrano, Bothamley, Welford, Hindley, Forsham, and Brier (of Bollington, near Macclesfield). On Tuesday there were excursions to Tavistock and up the rivers Yealm and Tamar, landing to visit Mount Edgcumbe Park and Gardens, and Cothele, by the kind permission of the Earl of Mount Edgcumbe. About seventy members with several ladies and local amateurs attended the invitation excursion of the Devon and Cornwall and Devonport camera clubs up the rivers Yealm and Tamar. A fine steamer had been chartered for the purpose, and an excellent luncheon was served. CoL Barrington Baker and Mr. R. H. Worth (local Hon. Sec.) were indefatigable in promoting the comfort of the visitors, who, early in the day, experienced heavy rain. Wednbsday. The weather, which on Tuesday had been very rainy and had some- what interfered with the excursions, improved as the forenoon of Wednesday wore on. A very large number of members had arrived to swell Tuesday's total, and more were expected, so that, numerically speaking, the meeting promises to be as successful as several of those that have preceded it. The group was to have been taken at mid-day in the Ouildhall-square. The past President (Mr. George Davison) was conspicuous by his absence from the Convention, for which no explanation was forthcoming. Next Y'eab's Convbntion. At the committee meeting held on Wednesday morning it was decided that the Convention of 18!)4 shall be held in Dublin. "ON A FAILURE OF THE LAW IN PHOTOGRAPHY THAT, WHEN THE PRODUCTS OF THE INTENSITY" OF THE LIGHT ACTING AND OF THE TIME OF EXPOSURE ARE EQUAL, EQUAL AMOUNTS OF CHEMICAL ACTION WILL BE PRODUCED." [A Communication to the Royal Society.] It has been generally assumed that, when the products of the intensity of light acting on a sensitive surface and the time of exposure are equal, similar amounts of chemical action are produced, and, with the ordinary exposures and intensities of light employed, such, no doubt, is practically the case, and any methods of measurement hitherto practicable nave been insufficiently delicate to discover any departure from this law, if such departure existed. In some recent experiments, however, I have discovered that this law breaks down under certain conditions, and I think the fact worthy the attention of those interested in the subject, since it is possible that these conditions may arise ■with other experimenters. Quite lately I have described the method of comparing the photographic value of sunlight with that of candle light (VhotHjraphic Journal, June, 189-3), which was as follows : — A beam of sunlight, after three reflections from plain glass mirrors, was admitted through a narrow slit to sensitive bromide paper stretched round a drum of about four inches in diameter. The drum could be caused to rotate round its axis at any speed up to about sixty revolutions per second by means of an electro-motor. A small exposure with this light was given to the paper during the lotation of the cylinder. Subsequently an amyl-acetate lamp was placed in position at any convenient distance from the same slit, and a fresh portion of the same sensitive paper exposed to its action during a much longer period, the rotation being continued as before. The slit was next replaced by a small square aperture of some half- inch side, and further portions of the - ime paper exposed to the amyl- acetate light at the same distance, for varying or unknown exposures, with the drum at rest. On develvment the paper showed three images, a narrow band of deposit of the width of the slit caused by the sunlight, a second band of the same width due to the light from the amyl-acetate lamp, and a third row of squares of varying blackness of deposit due to the different exposures given with the drum at rest. If the width of the slit be accurately measured, the band formed by the amyl-acetate lamp is evidently superfluous, supposing the usually accepted law to hold good under all circumstances, as by measuring the blackness, or rather want of whiteness, of the different squares, and using them as ordinates to the absoisssa which were the times of exposure, and drawing a curve through them, the blackness produced by the sunlight could be referred to that produced by the light of the amyl-acetate lamp, and its equivalent value in terms of the latter light be calculated. The band of deposit produced by the amyl-acetate lamp was introduced as a check, for its black- ness could also be referred to the curve, and the width of the slit be calculated from it. On making such calculations I was surprised to find that in every case the calculated width of the slit was always considerably less than what it was in reality, the difference being far beyond that which would be caused by any error in the measure- ment. This led me to commence an investigation into the cause of this difference, and what has already been carried out is sufficient to show that there is a failure in the usually accepted law. It may be pointed out that, if it held good, the sum of any number of very short exposures should be equivalent to a single exposure for the same length of time. The experiment which naturally suggested itself was to expose a sensitive surface to the action of the light of an amyl-acetate lamp passing through a slit as before, the drum on which it was stretched being caused to rotate at high and low speeds, and also to place on the same paper a scale of exposures with the drum at rest. These were all developed together. An example of one of many experiments is given as an illustration. The circumference of the drum with the paper stretched round it was 12-2.5 in. The width of the slit was arranged to be 0 012 in. The amyl acetate lamp was placed 2 ft. from the sUt, and a rotation of 30 per sec. was given to the drum for one exposure and 1 per sec. for a second exposure. In the first case the time of exposure during each revolution was c^-^t x --, sec, or about 1/30,000 sec. 12'2o 30 The sum of the exposures during 20 mins. was thus 1-176 sec. In the other case the exposure was ?^, or about 1/1000 sec, 12"2o and the sum of the exposures was, as before, 1'176 sec. Thus the first individual exposures had only 3'ti of the duration of the second exposures, though in the aggregate they were thf same. A scale of blackness was made on the same paper, through a square aperture, without shifting the lamp, the exposures being |, \, \, 1, 2, 4, and 8 sec. On developing it was apparent to the eye that the first band was much lighter than the second. The scale and blackness of the bands were measured accurately, and the times of exposure which had been given to each band, on the assumption that the law enunciated held good, was calculated and found to be for the first band O'O sec, and for the second band 0-91 sec, instead of 1'176 sec, which was really given in all. Another example is where the slit was opened to Oil in., and the time of exposure reduced from 20 to 10 min. It was found that in this case the exposures given on the same assumption were 3'7 sec. and o'28 sec, the real exposure given being 5-30 sec. The last experiment shows that if the slit had been slightly wider, or tha rotation slower, the law would have been approximately obeyed. Another experiment was made by throwing an image of the crater of the positive pole of the electric light on a hole bored in a plate about YTi in. in diameter by means of a lens, and allowing the emergent beam to fall on the slit and paper, the drum being made to rotate as before. The same kind of results were obtained. As it might be thought that this difference was caused by some action other than chemical, another series of experiments was under- taken. In these different sensitive surfaces were employed in order to eliminate any possibility of the effect being due to any phosphor- escence of the paper, though none could be detected. Plates were held stationary and exposures made by admitting light to portions of them through slits of known angular aperture, cut in a disc which could be rotated at any desired speed. Similar resulU were obtained to those already described. The quickest rotation gave the least density. It may be remarked that the more sensitive a surface is to radiation the less marked are the differences observable for the same speeds of rotation. This is what might be e.xpected. As an outcome of the experiments so far made, it seems that, when exposures less than -ixrVir sec. are made on a sensitive surface, and the source of illumination is an amyl-acetate lamp (Von Altneck's) placed 1 ft. from the sensitive surface, the law quoted ante fails. Tlie question of a very low intensity of light acting and of the sensitiveness to different spectrum colours is now occupying my attention. Captain W. de W. Abnet, C.B., F.R.S. July 7, 1893] THE RIUTISH JOURNAL OF PiIOTOORAPflY. 423 MY FIRST DAGUERREOTYPE. Thk interesting demonstration, by Mr. William Enpflnnd, of an almost forjfotten procefis, but of which he wss n most ilistinguislied exponent about forty yenra ago, surely must have been very (ittractive to those who were fortunate enough to witness it. At least, I know it would have lieen to me, and, indeed, to any one who had ever marred the pure surface of the silver plate by a failure ; for I never knew any one who had ever attained any proticiency in the Daguerreotype process who did not retain a lingering yearning for the revival of this lost art. In the recent editorial remarks on " Daguerreotyping," the editor said that " unlike all other systems of photography, the personal skill of the operator is the sole factor in the achievement of success." How true this is will be seen by the narrative of my early struggles with this difficult process; indeed, I might, with justice, use stronger terms, and say obstinate and refractory process, for so it proved in my hands just thirty-nine years ago. During the latter years of my apprenticeship, I had passed through the cigar-box-and-sixpenny-lens struggles with photography, and was rewarded by most complete and entire failure, but was more fortu- nate, however, in my printing efforts. Some paper negatives were fpven me by an amateur— who was, by the way, the instructor of Buckle, of brush fame — and I showed him my verj- imperfect results. A few hints helped me on, but the fearful price of the chemicals cleaned out the shallow pocket of the apprentice, and there were long and serious waits until sutKcient funds enabled me to replenish my photographic stores. In those days hypo was sold by the country chemist at sixpence per ounce : but, to encourage me, he let me have it at threepence ! Even at that price, however, the cost, from my point of view, was simply ruinous. In a very short time the serious business of life was before me, and I went to London to face the unknown. Of course, photography had to go overboard to lighten the ship ; in fact, the ship became too light, for frequently a biscuit, eaten m the National Gallery, was the sole furniture of my mid-day meal. The eye was fed, however, and that was something. I read every scrap relating to photography that came in my way, and thus theoretically got to know a great deal more about it, and patiently waited for liappier times when I might hope to ripen theory into practice. About eighteen months after my arrival in London I made a new friend, who absolutely had a practical knowledge of the Daguerreotype process. He had just returned from America, where he nad taken lessons in the art, and was looking about for premise? in oi-der to commence business. When he finally got to work and put out his specimens, I am compelled to say there was a marked difference between the examples of the art brought from America and those produced by himself, the artistic metit being most evident in the foreign productions. As time went on, his work improved, and his clientele rapidly increased. We lodged in the same house, and therefore I daily heard of his photographic doings, and I determined the moment I could get together sufficient money to make a start. I would take le.?sons of him, and try my luck also. After patient waiting the long-looked-for day came, and I took my first lesson in " Daguerreotyping." I need scarcely say this was a memorable day for me. .\fter eagerly watching the whole process through, from the poUshing of the silver plate to the final gilding operation, so well described in the article in this Joubxai,, already referred to, I saw that all I had read and done — or rather had not done — in photography would avail me nothing, and I had to com- pletely start afresh. The first business was to completely master the by no means easy art of buffing the plate, for upon the perfect doing of this depended the success of the final result. An absolutely " black " polish was necessary, and the faintest visible scratches, therefore, made the attainment of this impossible, and, in consequence, weakened the force of the shadows. It will be seen by this that, unlike most of the other photographic processes, black shadows W(;re necessary in order to obtain a brilliant as well as delicate Daguerreotype. Day after day I worked at " buffing," and found it hard work, ana, though it was winter-time, the coat had to come off in order to lighten the labour. The rubbing up and down on the plate with the long piece of wood, covered with buckskin, and treated with the finest rouge, seemed easy work enough at the start ; but, as the hours went on, the operation became tedious, as well as tiring, and I decided that buffing could not lie the most interesting part of Daguerreotyping. I sus- pected that my friendly instructor found this irksome part of his business quite as well done by proxy. At any rate, as time went on, with no change of employment, I mililly suggested that I wished to be something more than a photographic "buffer," and that the number of lessons agreed upon were rapidly coming to an end, and that only one stage on the photographic journey had been reached. I was assured that, when I had fully mastered this most difficult operation, I had little else to learn, as all the rest was comparatively simple. I thought of the master who kept hi« pupil at scales for seven year.^ when teaching him to sing, and, in reply to remonstrance, said, "Go forth, thou art the finest singer in Europe!" Perhaps, when I became an absolutely perfect buffer, I should astonish the world with mv unrivalled Daguerreotoyjie productions, so 1 worked on patiently. 1 think, if the truth were told, my friend was so busy, that not only was I useful, but I was less in the way when occupied by this neces-sary operation. ' My friend hail brought all his apparatus with him from America, and, as he had several surplus article.", he sold them to me. Amongst them was a camera of .\merican make, and I must say that, though it would be regarded as clumsy now, it was far in advance of the English cabinet work of that period. It was a bellows camera, and the woodwork was rosewood. The focussing screen was inserted soma distance in the camera, and was protected from the light, so that a focussing cloth was not necessary. A little trap-door admitted the former as well as the dark slide. When the latter was in position ready for operation, the shutter, which was of sheet iron, was pulled entirely out, and the lid of the camera shut down until the exposure was over. In those days a little extraneous light was not heeded, and the small amount that could get down the groove during the opening or shutting of the camera lid did not appear to affect the plate. The bellows portion of the camera was beautifully made ; in- deed, the whole instrument was a marvellous contrast to the clumsy wooden boxes made in England and sold as cameras. It would be interesting to learn when the first bellows instruments were made in this country. I can simply say that in 18.54 I had never seen one of English make. All the American silvered plates were slightly bevelled downward, and in appearance were not unlike miniature reproductions of the Venetian bevelled looking-glasses. They were lighter and cheaper than the Birmingham electro plates at first employed in England, and in consequence the name of Scovell — the American manufacturer of these plates — became known all over the world. This slight bending downward of the edges prevented any cutting of the tine leather surface of the buff, and also enabled them to be more readily fixed in the slight grroove of the screw block to which they were attached in order to hold them tight during the process of buffin". The American arrangement for holding these blocks of various sizes was very ingenious. The instrument was of cast iron, and in general appearance was not unlike the modem American burnishers. There was a broadish flat bar, slightly tapered and bevelled on the under side, so that the block carrier of the plate, which had a corre- sponding tapered groove, could be pushed along it until it was held tightly. The ends of this bar were bent upwards at right angles, and were furnished with pivots wliich fitted into sockets provided for them in two uprights, which formed portions of the more solid part of the apparatus, and which had to be screwed down to a solid bench in order to secure the necessary rigidity. When the pressure of the buff came on to the plate, the socketed bar took the necessary angle to ensure even contact between the buff and plate, and thus the friction was even all over its surface. A moment's consideration will show the use of this arrangement Had the plate been rigid during the process of buffing, the silver surface would very soon have been scrubbed away from the copper support at the edges. In those days there were .iome failures, even as now, and the cost of these plates made it imperatively necestary to use them over and over again as long as possible, for replating was nearly as costly as new plates. The American coating boxes as they were called were far superior to the English apparatus for applying the iodine and bromine vapour to the silver plate. As the constant inhaling of the iodine and bromine vapours would have in a very short time seriously affected the health of the operator, it was necessarj' to devise some efficient way to keep them imprisoned, and get always ready for work. The Americans employed two square shallow porcelain pans with the edges ground perfectly true. These were placed side by side in a box that was provided with a framed top which fitted closely on to ground tops of the pans. A sliding carrier with inner frames for the various-sized plates travelled from pan to pan along grooves in the wood work, but there was plenty of wood at each end of the carrier, so that, when the plate was over the iodine pan, the bromine one was tightly covered, and viae versa. This American contrivance was so much superior to all others that it finally drove all the rest out of the market. I wish I could speak with equal praise of the .\merican mercury bath, but I cannot, and for reasons which will appear later on. My friend had not one to spare so I proceeded to get one made on the 424 THE BRITISH JOORNAL OF PHOTOGRAPHY. [July 7, 1803 American model. The matter seemed so simple that I did not appre- hend any difficulty. All that was needed was a hollow cast-iron pyramid which had to be fitted on a retort stand, and made to slide up and down so as to adjust the flame of the spirit lamp in order to get the correct temperature of the mercury. Of course, the pyramid was fixed with its hollow base upwards, and on this was fitted the carrier with the silrer plate downwards, to receive the fumes of the mercury which was placed at the bottom of the well thus formed. A thermometer with metal index plate was attached to one of the outer sides of the inverted pyramid so as to record the right temperature of the mercury necessary for the development of the latent imag;e. Valentinb Blanchaed. {To be concluded.) DODGES.* The Printing Feame. A QUABTEB-FLATE picture Can be vignetted into cabinet or half-plate size by using a half plate printing frame with a piece of cardboard, the same size with an aperture cut out for the quarter-plate negative, covering the join with yellow or blaek paper, as in the example I show you ; the same arrangement applies to larger sizes. Plain and Fancy Bobdebs. At times yon may wish to have a margin round a print, perhaps a plain one round a landscape, or a fancy one for a portrait. For that pur- pose a mask must be provided of opaque paper, cutting out an oval, square, or any other chape desired ; place the outer portion on the nega- tive in its proper position, then the sensitised paper, and priut. By using a larger frame, and filling up the space round negative with card- board, a much wider border can be obtained ; a plain white border gives, I think, a neat and bold appearance to a print. It may, on other occasions, be desirable to print a fancy border, and it will be necessary then to make a negative of the design required, marbled paper or imita- tion morocco paper will answer the purpose. After printing with the plain border, the part already printed must be covered with the piece of opaque paper cut out of the mask ; slightly stick it in its place on the print, and print the border from the border negative provided for the purpose. There are several modifications of this style of double-printing which will, no doubt, suggest themselves as occasion requires. The Neoative. I now come to dodges in printing from the negative, and will suppose that, on examination of the negative, unpleasing defects are observed. There may be shadows too intense, one side thicker than the other, the foreground too thin, &c. All these matters want attention and correction, and for these and similar faults I prefer simple to more elaborate means, and I don't think there are many faults but what can be corrected by means of semi-transparent material, tissue paper, and the like. Use it in this manner : suppose the lens does not cover the plate sufficiently, the corners of the negative arc then thin and print dark ; in such a case, gum pieces of paper on the comers of the frame, to shade off the corners and 80 prevent any unpleasant appearance. A road is perhaps too dense : cover all except the road with tissue or yellow paper, one side of negative thinner than the other, and so print quicker, paste tissue paper over one Bide. Perhaps a central portion of the negative is thin, cover the whole of the negative with tissue, and a second or third piece of the centre, and so on — in fact, I know nothing more generally useful than tissue paper. It is also invaluable for thm negatives ; use one, two, or more thick- nesses ; in fact, any negative is better for printing under it. As an example, I show you a print from a negative of an interior, about the worst I can find, another print from the same negative dodged with tissue and yellow paper ; I think the superiority of the latter over the former is apparent. Another example is of a workshop ; the light at the window is rather strong ; consequently, printed as usual, it is unsatisfactory, but, if after printing to usual depth a piece of opaque paper is taken with an aperture cut the shape of the window, and the window is printed deeper, a great improvement is made. For landscapes a bent cardboard shade is very useful, and is a simple means to dodge a negative with a thin foreground. If any clouds are in the negative, it will help, if not entirely bring them out. I show you an instance of a print from a negative without a shade, and another using a shade, and I recommend you to try it. I first saw this idea mentioned in a paper by Mr. Blanchard, and I consider it a valuable dodge. • Coiiti::uc3 fro3 ra;e 410. Negatives are further dodged by working on the back. In the case of a group some of the faces may print too dark, in which case a light touch of pale blue paint on the back of the negative will improve the print ; also, tissue paper can be pasted on the back or gummed by the edges, and worked on with a pencil or crayon to increase the high lights, cutting away parts of the paper to increase shadows. I show you a portrait which I think treatment of this kind has improved. It is from the negative of one of our members, who kindly lent it me to experiment with. No. 1 is a print from the negative in its first state ; No. 2 the same after iotensification with mercury and ammonia ; No. 3 is after the negative had been backed with tissue paper and worked on roughly with pencil to take out the brick marks, also vignetted. The cabinet is from the same negative, printed in a half-plate frame as before described. Matt varnish on the baek of the negative is also another means of improving a print ; but, unfortunately, it is a dodge of itself how to get the varnish on the plate, and I do not think it will be out of place to describe how it is done. When you first try it, you will perhaps get the varnish oq the under side of the plate, or over your fingers, up your sleeve, and on the carpet ; in fact, anywhere except the right side of the plate. To practise the trick, I can recommend you thin gum water ; it doea not cost much if wasted, and it will flow in about the same manner aB varnish if not too thick. To coat a plate with matt varnish, the plate must be cold ; with spirit varnish, warm. Take the plate at the left-hand near comer by the thumb and finger of the left hand, hold it in a horizontal position, supporting it by the tips of the extended second finger. Pour the varnish in a pool in the middle of plate, then gently tilt the plate so that the varnish slowly runs to the corner held between the thumb and finger ; then tilt it to the other left-hand corner, then to the right outside corner ; finally, with one gentle sweep, pour the surplus off at the corner nearest you on the right-hand side, gently rocking the plate at the same time, to prevent lines forming. The plate must now be laid at one side to dry, and, when dry and hard, can be worked upon with pencil and brush, and parts scraped away with the knife to increase the shadows it necessary. This mode of doJging is useful to put clouds in a weak sky. Get a suit- able cloud negative as a guide, and, with pencil or crayon and stump to shade off, copy as well as you can the cloud negative. With a little practice it is easy to get passable results. A blue pencil is also one of the easiest articles to work with I have ever tried. When thinking over this matter, it occurred to me to try ground glass itself, and I think (after trial) that it has some advantages. It is remarkably easy to work upon, and can be used over and over again. To use it, take a piece of ground glass and place it, ground side up, on the top of negative, film side up. Work on it to increase high lights as usual with black and blue pencil, blue for medium effects. To increase the shadows it is not possible, of course, to scrape away the matt, but the same effect can be obtained by thin gum water. Put it on lightly with a small brush, the thinner the better (this is important, because, if thick, it will have a diminished effect), and let it dry. After doing what you think necessary, place the ground glass at the back of negative, the ground side next back of negative, then print as usual. A softer effect will be produced by placing the ground glass on the back of the negative, working on it and printing in the same position. In the former case only one thickness of glass intervenes between the ground side of glass and the film of negative, in the latter case there are two thicknesses. If you wish to use ground glass again, the work can easily be removed by that useful kind of soap that "won't wash clothes." Matt varnish is very inferior to ground glass in its liability to damage. Vignetting. There are many ways of doing this, and many effects to be pro- duced. A good plan is to make a cardboard screen for the purpose to go on top of printing frame, leaving a space between negative and cardboard. Cut a hole half an inch smaller than you wish your vignette to be, then gum tissue paper round the edges, also a piece of tissue paper over the whole aperture. This softens the effect to a large degree. It is also advisable — in fact, with gelatino-chloi ide paper, necessary — to stuff wool between the cardboard and glass to prevent the light unduly spreading over the whole print. Double Pbintino. I give you an example of this. On looking through my negatives I selected one with a cow, and decided to transfer her from Chingford to Hampstead Heath. I then printed the cow on a piece of sensitised paper, cut out the animal with a penknife on a piece of glass, and stuck tne piece cut out on the Hampstead negative in the position in which I July 7, ItiOS] THE BRITISH JOUhNAL OF PHOTOGRAPHY. 42S wished the cow to appear. The other part of the print was stack on the negative of the cow, so that tlie cow could be seen exactly in the aperture; the other part of the negative was then covered with opaque paper. The «ow was then printed on a piece of sentitised paper in the position re- quired, then a second print from the other negative, taking care that the resent is practically unknown, but which is one of the most Interesting in Europe. Fuller details of both tours are given in a pamphlet • supplied by the Association. Mb. Henry Blackburn's Studio for Instruction in Drawing for the 'Press. — The well-known art critic and journalist, Mr. Henry Blackburn, has opened a studio devoted to this purpose at 123, Victoria-street, S.W., which we hope to have the pleasure of visiting shortly. From an Educational Review ■reprint on the subject, by Mr. Arthur Montefiore, we learn that Mr. Black- burn is meeting with considerable success in teaching artists the requirements of work for photographic reproduction. We cull the following passage from Mr. Montefiore's brochure with much pleasure : — " This brings me to a question on which Mr. Blackburn is properly emphatic. Critics are continually inveighing against these 'cheap and nasty' processes, entirely forgetful or ignorant of the fact that it is 7Wt the process but the drauroces8es of toning after fixing. Emotions of THE Heart in Photography. — "Recently," says Mr. George Davison, in the Photographic Gazette, " addressing some art students, Mr. W. F. Yeames, R.A., sought to give photography its proper place in the training and work of the draugtitsman. It is something to find a painter admitting the actual use made of photography by draughtsmen. Almost without exception they get practical assistance in their drawing from it, and, in most instances, at the same time abuse and misrepresent it. Mr. Yeames admitted that photography lightened the labour of the draughtsman and extended the ranije of his subjects ; but, he averred, ' in no photograph did one see any expression of the emotion of the heart, which were qualities artists had to deal with.' How far a painter may legitimately or with advantage use photography will always be a matter of personal opinion. The tendency of all photography is to educate the eye of the public as well as that of the artist, and to raise the standard of excellence and correctness. As to expressions of the emotions, Mr. Yeames would probably find considerable difficulty in so defining his meaning as to exclude photography from getting such qualities into its produc- tions. The character of a worker may be shown in his photographs, and the more he learns of his technique the more subtle may be the signs of his individu- ality and perception. Photography, as Mr. Yeames stated, deals in facts, and expression of emotion is one of these facts. The kind of emotion one sees in ninety-nine out of a hundred of our Royal Acidemy pictures is certainly not out of tile range of the susceptible and capable photographer. Mr. Yeames may not know so much about ' emotions ' as about the use of mechanical photography. The brush will do mechanical work as well as the camera. When jiainters iliscuss such subjects, they generally find it convenient to use terms vaguely and without definition." Photographing in Norway. — Mr. Edward J. Smith, of Park Royd, Halifax, writes : " I have not sooner responded to your invitation for inform- ation on the above subject, hoping that some one having a wider experience would reply, but, a fortnight having elapsed without response, perhajis ray limited knowledge will be better than none. Writing, then, from personal experience, extending only so far north as Sogne Fjord, I should decideiUy say there is not much scope for a stand camera placed upon tlie deck of a steamer. In the first place the Fjords, though exceedingly grand as viewed with the eyes, do not lend themselves well in a general view to picture-making ; and, secondly, the deck of a steamer is about the worst place that could be chosen upon which to erect a tripod, unless the camera is pointed directly at right angles to the side of the vessel, which is the most trying position from which to take moving objects ; it is almost impossible to get the field of view free from ropes or spars, and, if the deck be at all crowded, one's fellow- passengers vote the sprawling legs a decided nuisance. There are a few ' bits ' that may be taken from deck, such as passing vessels, and the little landing- stages with their picturesque groups of natives, &c., but these are far more easily secured with a hand camera, which may be either rested upon, or held right over, the side of the vessel. When, however, there is opi>ortunity of going ashore, by all means take the tripod, and give as long exposure as jmssible. The special features of the barren hills arc entirely lost with snap exposures, whereas time exposures give in beautiful detail the bare limestone rocks and dwarf herbage. Trees in our sense of the word are unknown on the west coast. In August, I found that a Ross RS., used at/-ll, gave good droji-shutter exposures, but in Norway, as everywhere else, the only good exposure meter is * brains.' My best results were with /•64, and exposures from tliree to twenty secomls, according to light, llford oi-dinary. In passing, I may just mention I took two makes of plates; every llford expoaeu gave a good result, my failures were entirely confined to the other make. Some steamers are fitted with dark rooms ; but, if there is not this accommodation, a changing bag of some sort is necessary, as for some months there is not any night." 426 THE BRITISH JOURNAL OF PHOTOGRAPHY. [July 7, 1893 Fkaud by a " PHOTOORArHER."— On Friday, June 30, John Wilson, 48, described as a photographer, and formerly of Ipswich, was charged with having obtained by false pretences 4s. , the moneys of the Bev. W. R. Tate, at Walpole ; 2s. 6('., the moneys of Harry Sallows, at Halesworth, and Annie Booth, at Huntingfield. Mr. Blofeld appeared for the prosecution, and de- tailed the facts in the first case. The prisoner drove up with a horse and cart, and boy, to Walpole Vicarage, and told Mr. Tate that he had taken a photo- graph of the church, and .should like to take one of the house. At the same time he handed the Vicar a card, giving' an address, 5 Tintern-terrace, St. John's, Ipswich, and stated that all photographs must be paid for when onlered. Witness gave the man 4s., and he went through the form of photo- graphing the house, but no photograph was ever received. Ultimately the prisoner was apprehended by Superintendent Andrews, of Halesworth, at Lynn. The superintendent, who understands photography, searched the house, and found some twenty-six negative plates, but none of them relating to Walpole. He also found a camera and lens, but they were in such a dilapidated state tliat he was of opinion they were incapable of being used for the taking of a photo- graph. The inspector afterwards visited Tintern-terrace, and found one table left on the premises, but that was all. There were no signs of photographic processes ever having been carried out there. In his evidence, the superin- tendent added that he found at prisoner's lodgings at Lynn a cigar bo.\ containing some chemicals in boxes, but not sufficient to take one plate. Prisoner, in defence, handed in a photograph of a country seat at Lynn, and said that, if his apparatus were dilapidated, ne could not have taken that. The superintendent replied significantly that he saw those photographs on sale at Lynn. Prisoner emphatically declared the photograph was his own production, andhanded in another of another kind that he had bought to prove a difference. Charging the jury, the Chairman said the prisoner seemed to think, or would have them believe, they were trying the question whether he could photo- graph ; but that, of course, was not the issue. The real question was, whether he got the money by false pretence.';, and it appeared from the evidence that he had never supplied a photograph of the house as he had undertaken to do. ■The jury promptly returned a verdict of guilty. The prisoner mentioned that he had been locked up for three months. Mr. Blofeld did not proceed with the other two cases, but said he held in his hand a document showing that the prisoner had been carrying on the same practices in various parts of the county. The Chairman said he was aware of this, although, of course, he could not tell the jury. Complaints had been made about the prisoner in his (Lord Rendlesl'.am's) neighbourhood. Taking into consideration his detention for three months, the Court now sentenced prisoner to a further term of three months' hard labour. MtHinQ^ of SbocutteiEf* MEETINGS OF SOCIETIES FOE NEXT WEEK. Date of Meeting. July 10 „ 10 „ 10 „ 10 ,. 11 .. 11 .. 11 ., 11 .. 11 ,. 11 .. 12 .. 12 ,. 13 „ 12 » 12 ., 12 .. 13 „ IS .. 13 .. 13 ,. 13 » 13 ,. 13 .. 14 .. U .. 14 ,. 14 ., 14 .. 14 ., 14 .. 15 Name of Society. Darlington Dundee Amateur North Middlesex , Richmond Birmingham Photo. Society Derby , Great Britain Hackney , Manchester Amateur , Stockton , , Leicester and Leicestershire Leytonalone , Munster ..., Photographic Club , Southport , Stockport Birkenhead Photo. Aaso Glossop Dale , Hail London and Provincial Manchester Photo. Society .. North Kent Oldham Cardiff Croydon Microsoopical , Halifax Camera Club.... Holbom Ireland Maidatono Wast London HnU Place of Meeting. Trevelyau Hotel, Darlington. Asso. Studio, Nethergate, Dundee. Jubilee House, Homsey-road, N, Greyhound Hotel, Richmond. Club Room, Colonnade Hotel. Smith's Restaurant, Victoria-sl. 50, Great Ruasell-st. Bloomsbury. 206, Mare-street, Hackney. Lecture Hall, Athenseum. Mason's Court, High-street. Mayor's Parlour, Old Town Hall, The Assembly Rooms, High-road. School of Art, Nelson-place, Cork. Anderton's Hotel, Fleet-atreet,B.C. The Stndio, 15, Cambridge -arcade. Mechanics' Institute, Stockport, Y.M.C.A., Grange-rd., Birkenhead. 71, Prospect- street, Hull. Champion Hotel, 15, Aldersffate-st. 36, George-street, Manchester. Gravesend. The Lyceum, Union-street, Oldham, Public Hall,George-atreet,Croydon, Rooms, 15, Dawson-street, Dublin. ** The Palace," Maidstone. Ohiswick School of Art. Chiswick, 71, Prospect- street, Hull. LONDON AND PROVINCIAL PHOTOGRAPHIC ASSOCIATION. June 29,— Annual General Meeting,— Mr. Alexander Mackie in the chair. Mr. T. E. FitESHWATER read the annual report of the Committee :— Blevknth Annual Report ov the Lohdon and Provincial Photographic AsaociATioN. In submitting this report the Committee have to congratulate the members on the very sound basia on which the Association stands. There is a good balance on the right Bide, though this balance would have been much greater but for the large sum spent on the bindmg of so many volumes of the photographic journal* ; l)ut we have tne value, though not the cash, and, if we go on increasing the libraiy to the extent we have lately, we shall soon want another bookcase, so I will ask you to look around and see It yon can finrl another kind friend to give us one. There have been large gather- ingsof members and visitors. Many valuable discussions fcave taken place, arising ?™«i,- i^,"* *^'^^° ^^^ papers read by members and others well known in the photo- s'SwiTi.'AT"^^^ °^^^" being :~7nfensi/ifaf. 07), by Mr. Teape, the discnssion HaJ?™ ■*^it'"^,?^®"^°8ra; On a Sivvple Apparatui^ for Testing Oxygen, hj Ut, Haddon, assisted by Mr. Grundy ; Photographing Paintini 6y ArtHkial Light] by Mr W. K. Debenham ; On the Calculation of the Angle of Vie-w, by Mr. Everitt ; Retouch- ing, by Mr. Redmond Barrett; Investigations in Spirit Photography, by Mr. Traill Taylor, which has caused no small stir in the photographic world ; The Sandell Plate, by Mr. Fry; Determination of the Speed of Plates, by Mr. Williams; The Infumce of the Hand Camera, by Mr. W. D. Welford ; Is t:ie Present Construction of the Photo- graphic Studio Wrong in Principle ? by Mr. W. H. Harrison ; Development of instantaneous Exposures, by Mr. Parfitt ; Stereoscopic Photography, by Mr. Dando j Photographic Limits, by Miss Catharine Weed Barnes ; Various Rapidities of Printing' Processes, by Mr. Fonlkes Winks ; Flashlight Continuous Lamp, by Mr. Hudson; On the Difference in Bulk of Liquid Ammonia, by Mr. Haddon ; T}ie Hurler & Driffield' System of Testing the Speed of Pint es, by Mr. A. Cowan ; The Toning of CJdoHde Papers, by Mr. Welford. A course of Technical Lectures have been started, which at some future time it is hoped will be put together in book form. We have had one on The Lens, by Mr. Traill Taylor : On Camera, Tripods, and Dark Slides, by Mr. Clifton ; Or. ■ Developers, by Mr. E. J. Wall; and we hope this nest year to get through a good many more. The Lantern and Musical Evening was attended by nearly 350 members and their friends ; in fact, the large I'oom in the hotel was not big enough for the gathering. The Lantern Evenings have been much appreciated, and when Mr. Hindley showed his Irish slides the room was over-crowded. The Fortnightly Outings have not been so well attended as they might have been. The Library has had many additions and valuable gifts of books from the friends- of the Association, and they have been very carefully arranged by the Librarian, Mr. F. W. Pask. The Affiliation scheme seems to be successful. The Association has been ably represented on the Committee of Delegates by Messrs. Everitt and Pask, and much good work has been done- We have lost one of our most able members through death— that is Mr. William Bedford, and I think the last photographic meeting that he attended was that of this Association. There have been a good many new members elected during the year and several' resignations, and the Committee ask the members to do all they can to increase the- number and look around to see who they can bring into the ranks of this Association ; also, they ask the members to do a little more in way of getting papers to be read and subjects for discussion, and fifty-two meetings in the year are a great many and entail' a large amount of work in this matter. We cannot close this report without expressing our great regret that our late- Secretary, Mr. Drage, has been compelled to leave us. The Association has grown and made great strides during his three years of office, and we can only say that we- hope the long holiday that he is about to take will do him much good, and that we shall see him back again safe and well. The report, together with the balance-sheet, which showed the Associatiom to be in a healthy financial condition, were adopted. Two or three alterations in the rules were made, and votes of thanks to thfr various officers for their services during the past year were adopted. Mr. P. Everitt proposed, and Mr. W. E. Debenham seconded, a vote of thanks to Mr. R. P. Drage, for his services to the Association as Secretary" during the past three years, in recognition of which the same gentlemen pro- posed a resolution that Mr. Drage be elected an honorary member of the- Association. Both resolutions were carried by acclamation. The election of officers for the ensuing year resulted as follows : — Committee :. Messrs. G. W. Atkins, Thomas Bedding, J. Weir Brown, C. H. Cooke, P. Everitt, C. H. Oakden, J. S. Teape, W, D. Welford.— i:/^^a?-ia?i .• Mr. F. W.,, Pask. — Curator: Mr. A. Haddon. — Tmstees : Messrs. J. Traill Taylor and J... B. B. Wellington. — Ho7i. Secretary and Treasurer : Mr. T. E. Freshwater. A vote of thanks to the Chairman coacluded the proceedings. North London Photographic Society.— June 20, Mr. A. E. Smith in the^ chair. — Mr. Oakley referred to the meeting of the Affiliation Committee oiv June 6, which he had attended as one of the delegates of the Society, and.' reported that, stated shortly, the business transacted consisted of a balance- sheet being presented, and two sub-committees, each consisting of two dele- gates, being appointed and respectively commissioned to tilt with the English.- railway companies on the subject of reduced fares for photograpliers, and to consider what the Affiliation rules meant. Mr. Oakley had no doubt that the affiliated 5000 awaited the reports of these sub-committees in nervous expect- ancy. Mr. Walker showed prints on gelatine paper, the toning results being unsatisfactory. Mr. Bishop advised the use with this paper of the combined toning and fixing bath, made according to the formula recommended for Solio ■ paper. Mr Williams advised workers to make the chlaride of gold they used; and, preferably to others, from Australian gold coins, as these contained nO' copper alloy. Mr. Morgan then gave a lecture and demonstration on the Amidol, Metol, and Gtycin-Hanff Developers. He stated that amidol was essentially a developer for all-round work, whether for negatives, lantern ■ plates, or bromide paper. He especially urged the formula in which the dry orystals were added to the solution of sodium sulphite immediately before use, and, in cases of over-exposure, adding water and bromide according to require- ments— the last-mentioned even to the extent of three grains to the ounce of develoi^er. He. averred that a gooil printing negative could be made witKi amidol as a developer which had received only one-third of the exposure- neces- sary to produce one when pyro was used. Metol was a developer to be used in two solutions, one being the free alkali. It was not so powerful as amid(il, and any amount of tentative work could be done with it. For bromide-print.^- it bid fair to supersede the ferrous-oxalate developer altogether. He had been experimenting at the works of a large photographic company that day, and, as a result, it was admitted that metol developed a print equally well with half the exposure required when ferrous oxalate was used as the developer. The lecturer did not enlarge much on glycin, it being a more recent introduction ; but, from what he intimated, the audience concluded it would be a kind of automatic developer, such as the button-pressing fraternity would gladly hail' if they ever dared on development. You only harl to put the exposed film im. the solution and take it out when it was reduced to a perfect negative. Northern Photog^raphic and Scientific Association.- On Saturday, July 1, through the kindness of Mr. George Murray, F.R.S.E., F.L.S., a visit was paidj to the Natural History Museum at South Kensington, and a most enjoyable- afternoon was spent. It has been arranged to have an excursion every Satur- day afternoon throughout the sunmier. Next Saturday, July 8, there will be an outing to White Webbs Park and Enfield. Train leaves Broad-street ati five minutes to three ; Finsbury Park, twelve minutes past three ; Harring^y. July 7, 189:J] THE BRITISH JOUKNAL OF PHOTOGRAPHY. 427 ^G.N.R.), lit'teen minutes past three ; Ilorasoy, seventeen minutes jiast three ; Wood Green, twenty minutes past three ; and Bowes Park, twenty-two minutes past three. Eaat London Photograpblc Society. — June :^7.— A (luestion from the r. W. Pickett Turner, E.C.C.) in the chair.— Mr. Albert E. Bailey, Hon. Secretary, read the report for the jiast year, which was higlily satisfactory, accounting for weekly meetings during the winter, and weekly ■outings during the summer; a brief resume of the lectures, demonstrations, and public entertainments showed a very varied and interesting programme ha iui<- No. 1'2,65.^— "Improvements in Apparatus for Trimming PhotOKranhs " Complete specification. A. O.RKrns.—/)aledJune'iS, 1893° ' No 12.656.— " Improvements in and in connexion with Saturatore for use in Signalling, Optical Lanterns, and for similar Purposes." J. G Pahvin _ />«/(■(« y«n/; 28, 1893. 'Ainiiv. „T^m- 1^.734.— "An Appliance for Washing Photographic Plates and Print« "' W. Thcmson.— />ato;yu7ic29, 1893. ■•<:» aim rnnw. No. 12,839.—" Improvements in Tripo. KmK.— Dated June 30, 1893. ' " **"'"'"^- No. 12,840 —" Improvements in Apparatus for Storing and Exhibitinit Transparent P.ctures, Photographic Negatives or Positives, and the like'' y«(t'30'']893' "' ^''■''"'^■''' ^- •'^'^"*"'' *'• ^""°'"' ^"'* •'• P- KinK.-Dated No. 12,860.— "Improvements in Photographic Cameras." H H vov HocHUEHG, Piu.N-CE OK Vless.— Dated June 30, 1893. CorrejSiioiiDrence. IV OorrespoiKimts thovXi never write on hoih sides of tlie poper. No notice is lakta of coimiiitnications unless the name« and addresses of f/w writers are giwn, THE DOUBLE ANASTIGMAT OF 0. P. GOEEZ. To the Editor. Sib, — In The British Journal of Photography of June 23, page 396, Dr. P. Rudolph, of Jena, makes an attempt to submit to an unfavourable criticism the comparison prints published by Mr. C. P. Goerz. At the outset of his critique, hints are thrown out as to the validity of the patent, with the evident intention of favouring misconceptions by sup- pressing the true facts of the case. The type of construction which forms the basis of the double anaatigmat had already been made the subject of an application for patent in England on December 19, 1892, a fact which was well know to Dr. Rudolph. The latter had made experiments in March, 1892, with tie object of obtaining landscape lenses of good illuminating power, and claims to have, in the course of these experiments, arrived at the form of the separate lenses on which the double anastigmat is based. These trials have, however, not led to satisfactory results. Dr. Rudolph has not only admitted this fact in private conversation, but has also stated it in public. In his lecture, given on March 18, 1892, before the Freie Photographische Vereinigung in Berlin, on the subject of the Zeiss anastigmats, the elements of which he had calculated, he has made the following verbatim statement : — " The doublet type invented by me, is doubtless the only one by means of which anastigmatic flatness of field can be obtained without injury to the other properties expected from a good photographic objective." (See Photographisches Wochenblatt, Berlin, 1892, page 153, a.f.) If, therefore. Dr. Rudolph in his letter says that already in 1892— the time of his lecture — experimental objectives of the type of the double anastigmat had been made, I can only understand from that statement that such trials have produced negative results. I find my assumption confirmed in the work. Theory of Optical Instru- ments after Abbe, by Dr. S. Czapski, scientific co-operator at tlic optical works of Carl Zeiss. Breslau, 1893. Dr. Czapski writes in this work, after commenting upon the most important types of construction of photographic objectives, page 205, the f ollowing : — " At length en- deavours have been made, after abandoning restriction to two single component parts, to obtain improved effects by a combination of three lenses, single or cemented. These attempts, made in various quarters, have, however, not yet been rewarded with undoubted success. " In his specification for the British patent, dated March 3, 1893, Dr. Rudolph certainly says : " The practical question as to whether in a combination of the above description it is possible to obtain a sufficient anastigmatic correction, and at the same time to comply with the other conditions required in photographic objectives, has been answered in the affirmative by theoretical and practical investigation of both types of the new triple lens." But nothing is mentioned about the time when this affirmation took place, and only a sufficient astigmatic correction is spoken of — a rather elastic term. By calculating the elements of construction given by Dr. Rudolph in his specification for patent, I have been able to ascertain that both the detailed constructions show insufficient astigmatic and spherical correction. I have only closed my investigations, which have led to the construc- tion of the double anastigmat, at the end of last year, after years of preliminary labour, which, as far as I can show, takes me back to the middle of 1889, and after correction of astigmatism of the radial lines and of spherical aberration, I have found not only that there exist kinds of glass which induce achromatism, but also that these kinds of glass possess the property of reducing the secondary spectrum, and fnrthec, that astigmatism is not only eliminated from the radial lines which come first into consideration, but from the whole surface of the image, and 428 THE BRITISH JOURNAL OF PHOTOGRAPHY, [July 7, 1893 finall; that np to an angle of seventy-two degrees absolute flatness of field has been obtained. Not until I had safely recognised all these advantages did I feel myself at liberty to declare that I stood before an important inveniion, of which I do not intend to allow my priority to be removed by the incomplete labours of others. Lastly, I feel it my duty to make the following statement : — When we entered the double anastigmat at the Patent Office, neither I nor Mr. Goerz had the slightest notion of similar labours in this direc- tion on the part of Dr. Rudolph. We did not gain cognisance of this fact until we paid a visit to .Jena at the end of December last. On that occasion we were informed that it had then been resolved to apply for a patent on the basis of Dr. Kudolph's investigations. The circumstance, therefore, that Dr. Budolph, nevertheless, postponed his application until March 3 last, requires further explanation. I did not think myself justified to omit this remark, and the less so be- cause the communication on the part of Dr. Rudolph opens the widest field to misconceptions. As regards tbe critique on the comparison prints published by Mr. C. P. Goerz, I will now show that Dr. Budolph, though laying claim to the construction of the double anastigmat, has not even conceived the impor- tant advantages of the same. Dr. Rudolph asserts that the antiplanat and euryscope had not had a fair chance on account of the free aperture of /-6. What on earth has free aperture to do with astigmatism ? That with objectives possessed of un- avoidable astigmatism the effect of the latter can be diminished by a judicious arrangement of aperture and distance of lenses, whereby through timely vignetting a large portion of disturbing rays is cut off, was un- doubtedly known to the constructor of the lynkeiosooije ; he well knew how to successfully utilise this experience, and attained thereby that his aplanat, by employing larger stops, gives much better results than other objectives of a similar kind with the same size diaphragm. And that this is so the photographic prints are intended to show — nothing else. While, on the one hand, according to Dr. Rudolph, the antiplanat and euryscope are at a disadvantge by reason of their free apertures being too large, the anastigmat of f-1 '2 on the other hand is at a disadvantage on account of not being corrected for a larger aperture. There could be, surely, nothing more natural than to select from the price lists of the various makers objectives intended for the same pur- pose, and which in aperture and focal length approach as nearly as pos- sible the double anastigmat ; and of the Zeiss arastigmats No. 3 of series III. is that which in the just mentioned conditions almost com- pletely harmonises with the double anastigmat, while Series II. of the Zeiss anastigmats does not include a suitable focal length. Now, Dr. Rudolph asserts that no disadvantages would have resulted to the Zeiss anastigmat against the double anastigmat, if instead of a Zeiss anastigmat of N7-2 one of /-() -3 had been drawn into competition. But instead of supplementing the published comparison prints by a corre- sponding photograph taken with a Zeiss anastigmat of A6-3, which would at once have decided the correctness of his assertion, if founded, Dr. Rudolph produces in evidence of his statement certain prints which have been obtained under chosen conditions of disadvantage to the double anastigmat. Even though stopping down to/-15-5 cannot be admitted as a measure for the examinations of systems of strong illuminating power, the result in favour of the Zeiss anastigmat is still further removed by the circum- stance that Dr. Rudolph approaches the object to the short distance of 1-2 meter with an objective lens corrected to an infinite distance. Of what worth such manipulations are I leave to the judgment of any unpre- judiced person. I am prepared to repeat the photographic exposures as represented by the prints with a Zeiss anastigmat of Series II., under the assistance of Dr. Rudolph or his representative, and declare emphatically that such exposure can only lead to further confirm the superiority of the double anastigmat. The reproach that the two first objectives of the photographs have a shorter focus than the three others may have some justification, but as only specimens of this focal length are in commerce, nothing remained for Mr. Goerz than to use them. Moreover, any one with a technical knowledge can easily appraise and take into account the amount of the defect which may arise from the slight difference of the focal lengths, from the data given with each of the prints. From the unequal definition of the two sides of the photographs. Dr. Rudolph infers that not the centre, but one of the sides, of the plate had been focussed. This assumption is erroneous. The unequal sharpness has much more its cause in the fact that the iron rails by which the Stegmann apparatus for reproduction used for the production of the originals was guided, though accurately directed upon the centre of the trial plates, were placed, as I could ascertam after closer scrutinv not completely vertical to the plate. Tliis circumstance, which affected uniformly all the exposures, cannot, however, in any way be considered a fault which might induce erroneous conclusions. On the contrary it 18 particularly well adapted to demonstrate the difference in the lateral want of definition with objectives more or less corrected for astigmatism Finally, Dr. Rudolph objects to the omission of the author's name on the prints. In producing the originals for the photographs, we have been assisted in a most amiable manner by Professor Dr. Gustavo Tritsch, privy- medical counsellor in Berlin, for which assistance we acknowledge our- selves to be greatly Indebted to him. Professor Dr. Tritsch, to whom the- prominent qualities of the double anastigmat at once became evident, exhibited such lively interest in this new objective, that he has sacrificed several days in testing them, and was not only present at the production' of tbe originals, but also at most of the extremely painstaking, and sometimes tedious, preliminary labours. The placing of the plates was separately executed by all persons present, in order to render ourselves as much as possible independent of personal! errors, and exposure was nnt made until the placing by all agreed. Present were : 1, Privy Medical Counsellor Professor Dr. G. Titsoh ; 2, Mr. Paul Goerz ; 3, the undersigned ; 4, Mr. Biffarth ; 5, the operator of the Institute for Reproduction of Messrs. Meissenbaoh, Riffarth, & Co., who developed the plates. With each of the objectives taken for trial at least two exposures were- made, and the best only used for the prints. If Mr. Goerz has omitted to attach to the prints the name of Professor Dr. Tritsch as author — this Dr. Rudolph no doubt has meant — it was done- chiefly for this reason, that such a notification could only produce the im- pression of an advertisement, which in my opinion our double anaatigmats are not in need of. With a subject of such importance it cannot fail that, very soon, scientific authorities who have no interest in either side will comment fully upon the questions which here come into consideration. I can only welcome this in the interest of my good cause. Asking you. Sir, to kindly admit the contents of this letter to youc- esteemed Journal, — 1 am, yours, &c., Emii, von Hoegb. Berlin. THE COls-CENTBIC LENS. To the Editob. Sia, — I had not intended troubling you further in this matter until some reliable independent testimony was obtained, but I am unwilling to- let Mr. Stillman's letter of June 8 remain so long unanswered in face of the unfair charge he makes against me in his postscript. Mr. Stillman is no ordinary controversialist. I was provoked, in the first instance, to lodge an emphatic protest against a statement that seemed to me inaccurate and misleading, twice repeated — a claim for thet lens that is repudiated b.v the makers and has no foundation in fact. That 80 insignificant individual as myself should presume to question Mr. Stillman's accuracy, and suggest that his facts are fancies, seems to- have roused his indignation, but we Yorkshire folks are a plain, practical lot, and have a habit of sticking to a point until proved right or wrong No amount of indignation will crush us, and if we get into a dispute we; accept the responsibility. Just note how Mr. Stillman has performed the operation known as: " climbing down." At first he contended that the concentric defined as- sharply at/- 16 as at/- 64 over a plate as large as the focal length of lens. Then he changed to " any given object," and now he has watered that; down to " such definition as meets his requirements." Had he said this- at first, this controversy would not have arisen. Then Mr. Stillman's style of argument — a long letter, not to me, but certainly at me, in which he commiserates other users of the lens for not achieving the impossible because -we have not a nice delicacy of touch, or^ our cameras are not sullioiently well made, while Mr. Stillman proves his superiority by admittedly sending you a partially developed negative- taken in a camera with a cracked front. Our cameras must be very bad. Mr. Stillman's own interpretation of my protest was, that if I was right his contention was " brag, or worse." Now, he says I may take any course I like to prove my case, as "it does not concern him in the. least." This is the same gentleman who contended that the instructionsr sent out by Messrs. Ross with the concentric were " illogical " because- they did not support his views. Mr. Stillman is an excellent judge of what is illogical. In conclusion, I regret I am unable to accept any advice from Mr. . Stillman in the matter of courtesy. My letters have been very much on the same lines as his, and if I have sinned in this respect he is not en- titled to reproach me. I take it as a little ruse to cover his retreat. I will send a concentric to Kew, and submit the report to you in due course. Whether for or against, we will have proof, which will be the one graii*. of wheat in this mountain of chaff. .».j - ^^i Thanking you in anticipation, — I am, yours, itc., F. H. Bcbton. j Roniulhay, near Leedf, June 27, 1893. IMPROVEMENTS IN PHOTOGRAPHIC LENSES OR OB JE CTIVES. To the Editor. Sir, — Apropos of new lenses that are now being issued, permit me t^)- say that in Patent No. 1261, of 1889, it was not my intention to place- upon the market a new lens of such formation and advantages as that. existent objectives, single or double, rapid rectilinear or wide-angle, should thereby become obsolete, but, on the contrary, by the use witU- July 7, 1803] THE BRITISH JOURNAL OF PHOTOGRAPHY. 420 thorn of my patented combinations of greater public utility, that this end should be attained by aimple, yet correct, means, and, at the same time, that a great saving to the photograpliic artist should be eflcoted. That these desired results have been, and can be, obtained by the series of combinations specified in my patent cannot truthfully be denied. They are partially placed on the market in the French goods of F. Darlot & Co., and brilliant results are secured when, in workshops of British experts, the lenses arc carefully centred and ground or selected exact to specification. That such combinations are absolutely corrected is proved by the fact that in the proportions specified no alteration can be made witliout detriment to their symmetrical definition, either in the centre or in the outer edge. Owing to the facilities afforded by such a formation for obtaining a deep globular field (with the smaller stops in use), or, reversed, a flatter field (with the larger stops in use) ; or for obtaining an exceptionally deep, long narrow field, such as the cabin of a steamer or a long corridor (when, in such case, they can be placed one in front of the other in the spiice between the plane of the diaphragm and the front collecting objective of a half-plate rapid reatilinear doublet, or of an Optimus 10 x 8 rectilinear, wide angle, or other doublet) ; or, again, a narrow angle for obtaining a view of a dist.'uit subject (when, in such case, they may be placed at point, so called, of principal focus, outside and at rear of any photo- graphic doublet, or single ordinary achromatic lens, and whereby, also, " instanto " effects may be obtained) ; the combinations, by preference, consist of four parts or pieces, two positive and two negative lenses, after a manner described in my specification, and divided into two separate cells, which whole combinations can, as aforesaid, "be applied in or irith any photographic achromatic lens ; astigmatism being corrected for, it follows that a correct media being added to any correct media the whole is correct, whilst a symmetrical and " the most accurate resemblance between the object and the image is secured," as shown in copies of finest engravings. Consequently, as before written, it was no point of mine to interfere with the construction of an outer front collecting, or, in doublets, rear dispersing objective on lines as made previous to date of my patent, but to provide combinations to become, as it were, handmaids to render them increasingly effective and useful. Such being my case, it becomes my duty to, on the foregoing and on other grounds hereinafter stated, again present the claims of my Patent, No. 1261, of January 21, 1S8!), befor the public photographic world. I. It would be superfluous to correct that which is correct, and these absolutely correct media are found specified in the first series mentioned in Patent Xo. 1261 ; they form the key to guide the construction of equivalents, as mentioned in following series, which were purposely inserted by me to prevent infringements. British opticians do not, of necessity, require the aid of other experts to calculate in two or three part the equivalents of the faid series of four parts (as, for convenience, placed in plane of diaphragm front and rear of a doublet, with an air space between such, as is afforded by the stop-slot, width of angle being attained and retained, together with increased or decreased size of object, at will of the operator). To many the various series quoted in my patent seemed to be superfluous ; but, upon examination with the first key-guide series, they will be found, I am well assured, to cover all needful ground. Some months back a Resident Barrister mentioned to me that, in experimenting with an ordinary achromatic lens, instead of a stop, he placed behind it a piece of tinfoil, and, no matter in what part of that piece of tinfoil he pricked a minute pin-point hole, he found a perfect picture delineated on the screen or ground glass behind. This, in the minds of most people, will argue ill for the correctness of calculations dogmatically describing the formation of lira partial focal points, formed by rays passing through " the meridional and sagittal sections respec- tively (why so called, one ray shoots as much like an arrow as does another wherever it gets through?). It follows, then, that that form of lens, or combination of lenses, which in practical work gives the best all-round results, will commend itself for use. II. Correction for " astigmatism" will, in the rapid rectilinear doublet, be found to be a correction for " residual error," lying between the points A (at top-slot) called " principal focus," and other points between it and the points B (at rear-objective), called " conjugate foci ; " this, in a very complete measure, is got rid of by insertion of my combinations at A, making these combinations principal to the front collecting objective, and transmittents to the rays passing through it ; and B, the rear objective, become principal to the combinations at A, whereby " residual error " is so removed. This will be found to be the case with any rapid rectilinear doublet by a conscientious maker of repute ; and is proved, by the interior (15x12) of the Crystal Palace, taken by Negretti & Zambra with my whole-plate, eleven and three-quarter inch focus, rapid rectilinear doublet (Fallowfield), the focus being increased by my combinations to fourteen and a quarter inches e(iuivalent focus, stop of a quarter inch orifice. Lines — of the multiplicity of iron pillars of the vast building — rectilinear ; and girders sharp to outer edge of circle of the image, received through the front collecting objective, and whereby great width of angle is obtained, to manifest advantage. III. By placing the combination of four parts, contained in the two separate cells, in the plane of the diaphragm, they act either as a collect- ing or dispersing lens to the front or rear lens of a photographic doublet. Used singly with them, as may be desired by the operator, rectiline&r lines being in marked measure still secured, and with a comparatively small stop, objects from twenty feet to over three miles are delineated in good definition or focus. Again, the " compensating " part of my com- bination in cell by itself may be allowed to remain in its position in the plane of the diaphragm, and the other portion, in a cell by itself, be placed at the point previously occupied by the front or rear lens (of the doublet), whicli had been unscrewed and removed for that purpose, and the correction for " residual error," mentioned above in Section II., becomes distinctly marked and observable. Therefore it appears clear that the position at point called principal focus, in which the combina- tions are placed in their connexion with "an ordinary achromatic lens," has to be considered rather than a fixed system of calculations as to " radii of curvature of the surfaces of the lenses," and " central thick- ness of the lenses." As, again, as a general rule, the radii of curvature of combinations must perforce have that relation to the radii of curvature of the " ordinary achromatic lens," or lenses, in conjunction with which . they may be used — as have the various inner skins of an ordinary Spanish onion in varying "radii of curvature" to meet the require- ments of the radii of curvature of each outer skin to which it is. adapted, be that onion of what size or shape it may. But the shape of the human eye might, under the same conditions, be followed to- advantage, and Professor George Butler Bradshaw (Gold Medallist in Science) Informs me that the eye of the sparrow sees the hawk before the hawk's eye discerns the sparrow. The variation of radii of curvature of positive and negative meniscus lenses of from three and a half inches to seventy-two inches focus has been offered to be done for me by a London . maker of such lenses, whilst it will scarcely be disputed that ho optician would rightly be considered as an " expert " who was not an fait as to the methodical fulfilment of such requirements with the "ordinary achro- matic lens," or lenses of any diameter with which he purposed to use combinations of lenses. IV. The question, then, of correction for the astigmatic aberration of simple ordinary single meniscus lenses may be tested by taking any pair of positive meniscus lenses of, say, sixteen Inches focus, either of. which, viewed through by a person of normal sight, will "neutralise " a negative ordinary single meniscus lens of same focus, in such a manner as that a series of parallel lines, a quarter of an inch apart, will be found of exactly the same distance apart whether seen through the two neutralising lenses or on either side of them. Similarly, this pair of positives of sixteen inches focus— placed one on either side of a negative meniscus lens of eight inches focus, and found to neutralise it in such measure as that the same series of parallel lines will also still appear equidistant, whether viewed through the three neutralising lenses, or on. either side of them (at points of impact and epact, so to speak, respect- ively) ; then either one of those two positive lenses may be used with that eight-inch negative as its corrector for astigmatism, subject to (after a similar process of testing) a positive ordinary single meniscus lens of forty inches focus, placed with a negative meniscus corrector lens of eighty inches focus, being together used with the previous mentioned pair as a compensator. These four parts, inserted in two separate cells (or cemented together or in pairs), as described in Patent No. 1261 ; the curvature* regulated as mentioned in Sec. III. herein ; used in or with an ordinary achromatic lens or doublet, "with a single or divided objective tube," and placed at the point called principal focus, which may be either in the plane of tbe diaphragm, or in front, or at rear of either a single ordinary achromatic lens, or rapid rectilinear, or wide-angle doublet. It will be found that no one of these four parts can be replaced by any other lens of a different focus, even a shght variation shovring a tendency to • introduce spherical or other aberration. It will also be found that the positive may be separated from the negative at certain varying distances, if what are called " tele-photo " results are required with a short-focu& camera. To borrow, then, a simile from Lord Salisbury's speech at Derry : — Should "Infringerites" attempt to introduce into the British land of. Canaan improvements in lenses which are already effected under a British, patent of January, 1889 — now that these plain facts in connexion with . the patent (No. 1261) are agiin pressed upon British opticians and the scientific world, specifying a mathemotically exact principle of construc- tion and correction, I hold that a syndicate of experts behind Patent. No. 1261, as a rampart, would be unassailable before any court. Be this as it may, my desires have never extended beyond re3. Pioneer. AMATEUBS AND PEOFESSIONALS. To the Editor. Sir, — I beg to express my thanks for permitting me in your issue of June 30, to defend the occupation of shop-keeping from the imputation of degradation made against it by one of your contributors. I would further like to make a few remarks on the vexed question of amateurs and professionals. One of your correspondents suggests that amateurs would be wiped out if they had to pay a tax of ten or twelve guineas a year; undoubtedly they would. Seeing, therefore, the remedy is admittedly potent, why is it not applied ? Well, in the first place, photography was not invented for the purpose of giving a body of professionals a monoply of the art, and one man has as much right to practise it as an amusement as another has to practise it as a business. Can your correspondents be so childish as to suppose that Parliament will pass such an absurd law — they are surely joking? Only a short time ago a Lancashire County Council or Local Board proposed to the Chancellor of the Exchequer that cyclists should be taxed five shillings per year. The proposal was not entertained for a moment. Undoubtedly there is much to be said on the professional side. The amateur does, to a small extent, affect the trade, but the remedy is not Acts of Parliament. The only way in which amateurs can unfairly compete with pro- fessionals is in the line of underselling them, or in giving photos away free. We must appeal to the good feeling of amateurs not to act so thoughtlessly. If they must take photos for money let them charge the proper price, and if they can afford to do them without receiving pay let them carry round a subscription card for some hospital or charitable institution. Then, when a person wants a portrait doing, do it on condition that a subscription for its value be given to the charity. Of course there will be exceptions to this rule ; there are times when it would be correct and proper to make presents of photos to our friends, such as views, and special subjects of a like nature. But let no amateur practise the indiscriminate free giving of photos. It will only tend to make them common and unappreciated, and when a charge is made let it be the usual professional charge for the same class of work, whether the amateur keeps it himself or devotes it to charity. Then, in my opinion, professionals will have no need to complain of the amateur, and the problem will be solved. They have just cause to com- plain of the amateur who undersells them or gives away his work for nothing without discrimination. Could an association be formed of amateur photographers binding each member to those terms, it would help to bring about the result so much •desured.— I am, yours, &e., William Ja.mes Farmer. 68, Blttckhurn-street, Lundon-road, Blackhurn, July 1, 1893. To the Ediiob. Sir, — I am sorry to see so many foolish utterances in the Jocrnal on this question. It is so evidently impossible to restrain amateurs from the use of the camera, or from selling their productions if they find buyers, that it is the veriest waste of time and material to print the absurdities which have lately been written on these matters. As well might the professional bakers seek to restrain home-made bread, dressmakers to prevent unlicensed infringement of their sphere, authors to tax the unprofessional essayist, and so on with every trade in the country ! Is it not true that most trades are at present depressed, and people of all mercantile pursuits complaining ? There are causes for the depression in photography which are very plain to be seen do we but look for them. " To him that hath more shall be given." Yes, if he does good work, and spends largely in advertising. Nay, sometimes it is bad work that pays best ; the flattering retouch- ing, the untruthful effect of unnatural lighting, possible only in a studio furnished at great cost with an elaborate system of blinds and reflectors ; these, and the magnificent " get-up " of the studio of the monied man, take a large slice from the general run of photographers. A little lower in the scale commences the system of price cutting, of taking small orders and making up for it in number of sitters, overwork- ing and underpaying assistants, running a number of branch studios for the profit which should be obtainable from one. Panic fear of each other is a large factor in the present crisis. If it happens that the next stand, however unpromising, is working at lower prices than, say, mine, down must go my prices, however inferior hia work. Grabbing at one another's business, competing for estimates where the lowest tender is always accepted, and other things not so patent to the public, all combine to make our position what it is. We are largely paying the penalty for our own sins, and it is purblind folly to lay the blame on the amateur. A certain man took transfers for 3s. 6(2. minimum. Being one day asked for a block, he took the transfer, paid 2.v. 6(/. for etching, and fur- nished the block for 3s. 6d. Why? Because he heard that somebody in that trade was doing them for so much. (I generally publish my name, but wish not to do so in the present instance.) Some of the very best work I have ever seen has been done by ama- teurs, and some of the most valuable discoveries of photography have been made by amateurs. To deny it is to plead ignorance of the history of photography. But what is the cause of these causes ? How comes it that we find ourselves in the toils of advertising monopolies, price-cutting, falsifying, labour-sweating, seven-day working, neighbour besting, toiling for nothing? The answer is to be found, but it has nothing to do with photography ; therefore, unless at special request, and by special licence of the Editor, I shall not divulge it. Indeed, to many correspondents on the subject, it would, I fear, be unintelligible. — I am, yonre, &c., June 29, 1893. Individcal. To the Editor. Sir, — No one can fail to sympathise with the unfortunate professional pliotographers who, while suffering tlirough the laws of political economy, lay all or most of the blame on the amateurs. The recent suggestion that the latter class should pay a heavy licence for the privilege of carrying a camera points out the most practical way of dealing with the matter. There may, however, be a good deal of conservatism to overcome before such a tax could be imposed, and as the ranks of our legislators include a number of amateur photographers it is to be feared that a certain amount of class prejudice will oppose the scheme. The suppression of the amateur will, doubtless, seriously damage the manufacturers of plates, cameras, Ac. The latter will find it to their interest to pay the tax for the amateurs so as not to lose such good customers. If this happens the National Association of Professional Photographers will, of course, have to buy off the opposition of the manufacturers. The financial results may prove complicated. The principle of taxing those who amuse themselves with any occupation outside their own trade or business is too good to be applied only to photographers. As soon as the public have been educated up to it, we shall of course tax amateur carpenters, gardeners, soldiers, ei hoc genua oiime. They all interfere with those engaged in the corresponding trades. The Chancellor of the Exchequer would be only too delighted, and many vexatious duties (including perhaps the income tax) could then be taken off. I would only suggest that the snap-shottist be exempted from the proposed licence. Such a large proportion of his shots are failures that he greatly benefits plate-makers, without doing any appreciable harm to the professional photographer. — I am, yours, Ac, Econoiiisi. July 1, 1893. July 7, 1893] THE BRITISH JOUKNAL OF PHOTOGRAPHY. 431 LEYTONSTONB CAMERA CLUB, SECOND ANNUAL EXHIDITION Ti) tlu Editob. Sir,— Owing to the great snccesa and overcrowding attending our First Annual Exhibition held on last November 10, 11, and 12, the Conncil o( this Club liiive decided to extend the time this year to a week. The date is also lixcd, and itwill be held at the Majonic Hall, High-road, Leytonstone, opening on Monday November, 20, and closing on Satur- day, November 25. Further ))artioulars will be duly announced, and it is earnestly hoped that our numerous photographic friends who sup- ported us HO well last year will do so again this year, when we hope to eclipse our previous efforts. — Yours faithfully, Ai.hebt E. B\ii.ev, Hose Bank, South iVentronil, Lei/tonstone. Hon Sec " MUSIC HATH CHARMS." To the Editob. Sib, — My attention was lately attracted by an advertisement which appeared in a popular photographic journal demanding the services of a "musical retoucher,'' the particular quality of voice required being soprano. This appears a novelty in the way of orders, but one which, I am sure, will be readily filled. In the mean time " wonderment guesses " why is such a combination desired, and to what more or less useful pur- pose will it be applied when found ? Perhaps the best way to satisfy my curiosity would be to wait until a retoucher with a tenor voice is applied for, when, perhaps, it will be my good fortune to be selected to take part in a "retoucher's madrigal " or a " stripper's roundelay." Whether or not such happiness will ever be mine, this idea of combining two hitherto widely separated vocations seems a happy one, and is rich in suggestions. Attending, first, to such as are quite utilitarian, and therefore business- like, one might suppose that the system of having a retouching depart- ment conducted on harmonic principles would answer very well. I know by experience that singing is a great relief to the nervous tension caused by prolonged application to such tedious and monotonous wprk as retouching. I knew a surgeon who had a habit of whistling softly the air of some old ditty — a cross between a jig and a country dance — when performing the most skilful and perilous operations ; doubtless he did so in order to keep himself cool and his hand steady. Many employers think that yon cannot do two things at once, and discountenance talking and singing whilst at work. Talking may be bad, as it is apt to become controversial and take up too much attention ; but there is not the same objection to singing, as long as it is not of that class which requires the accompaniment of gestures and poses, or too many " runs " and " shakes." Singing acts beneficially on the circulation, remedying in some measure the ill effects of sitting ; moreover, the energies receive that stimulus which the work cannot give, activity is sustained, one is prevented from falling asleep, or quarrelling with his neighbour, unless it be over a ques- tion of "tempo" or " pitch," the work receives less begrudging attention, and the result is — progress. Shakespeare says, " The man who has not music in his soul is fit for treasons, stratagems, and spoils." He does not particularly allude to re- touching, unless in the last part of the sentence he refers to spoilt nega- tives. In connexion with this notion of employing stippling songsters, or singing stipplers, many amusing thoughts present themselves. One can picture the spectacle of an energetic foreman wielding the baton, which might in this case consist of a retouching pencil, and seeing that the bows — I mean the other pencils — keep time with the music. He prefers pieces that have an "allegretto" movement, deprecates anything like " adagio," but has a partiality fbr " accelerando al presto." A " photographic establishment choral society " might do double duty, so many birds might hit two objects with one stone — by being placed in proximity to the studio their harmonious breathings would serve to evoke that lively and amiable expression of countenance in the sitters which it is the aim and endeavour of all good operators to obtain. Experience would soon show whether the best singers turned out the most artistic retouching, which we might expect them to do by dint of their mental faculties being elevated and quickened to a perception of the beautiful, whether it be found in the graduated tones of a negative or in a modu- lated scale. Certain it is that amateur vocalists are so fond of exercising their voices and their talents that many would be found anxious to acquire the art of retouching in order to gain admission to such musical salons as the retouching-rooms of the future promise to become. Finally, we can imagine the fashion extending to other departments, until at last it becomes a sine-'/ «« -now in an operator that he be also operatic, and it may even lead to a solution of our present " Depression in photography " problem, for if once the public takes to the new photo- musical fad it will only patronise those establishments which are ready to add to the allurements presented by a system of rendering the harshest and plainest of features soft and agreeable, the further attraction of being dissolved into ecstasies by strains of the sweetest music, vocal — and it may come to this— instrumental whilst waiting one's turn in the reception-room or undergoing the process, which will no longer be stigmatised as the " ordeal " of being photographed. The subject is so charming; bat I must tear myself away from it, sufiicient to say that by the time that th« last-named state of thtng.s shall be unfait ncrompli, the- profession shall have been subjected to euch complete and remorseless action of the laws of natural selection and the survival of the fittest, that the unmusical among them will have disappeared, leaving the fiddling photographer more elbow-room for his scrapings and the photographic flautist freer space and air as he " softly purling glides on the even tenor of his way." Simultaneously another vexed question will be settled, the last element of discord will be eliminated, and all photographers hence- forth will hold the undeniable and inestimable privilege of calling them- selves artistes, with or without the "e." — Yours, >l-c., July 1, 1893. The Piriso BvLrtscB. COLOURED LANTERN SLIDES. To the Editob. Sir, — We notice in the Jane issue of " Supplement " to Tbe Banam Journal of Photooraphy an article taken from the Photographic Timet, written by Mr. L. C. Laudy, and must say we fully endorse what he says about " the need of more trained artists in the slide-colouring line." He very properly denounces the " rubbishy painting extant — harsh, wild, and sensational colouring, and that those who are induced to try their hand may avoid the above, and restrain that childish appetite for lurid and glaring effects, and be guided by a rhante and educated taste." He then, adds, "The field of lantern-slide colouring is an excellent and tempting, one .... will bo delightful and bicrative in its results." (The italics are ours. ) Now, we wish to add a few remarks, the result of nearly half a century's experience in painting slides by hand, and colouring photographic slides. The majority of the public refuse to pay a fair price nowadays for the - colouring ; the cheap ISjj. a dozen complete (photograph and all) have done it. Our dealers say they " cannot sell the true artistic work, and that a ifood slide bij an educated artist would be passed by as tame and poor, r tricycle, as nevr, cost 26i. n^t, or 24x18 hot rolling proas. Addi-esa, J. Aston Brioos, Whitby. Wanted whole-plate studio cameni, with two doable back^ and carriers. Will ex- change a 15 X 12 enlarging, &c., camom, with full set oarriors for same. — Addreaa, H. Wii.Kiiisoif,2, Church-greeu, Harpend«u, Herts. Will exchange Thk British Journal of Photo»eapht from 1989 to 1898 (indniiTe)' and a fow odd numbers of Vfwtoijraphy lor graduated background or interior. — Address, Fredk. Hcbd, Photographer, 'Shepton Mallet. Will exchange a IS x 12 reversible camera, long extension, with two double and one- single slides, for a 10x8 folding bellows camera, with three 9Ude«, doable. —Addnas, JoHH BaooKS, Photographer, 40, Parliameat-atreet, Bnmley, Lnno. 432 THE BRITISH JOURNAL OF PHOTOGRAPHY. [July 7, 1893 Ensftoer^ to (ttorrcsponUcntB. -*,* All matters irUmded for the text portion of this Journal, including mwries and Exchanges, must he addressed to " The Editor, Thb British Journal op PHOToaRAPHT," 2, York-street, Covent Garden, London. In- attention to this ensures delay, *,• Correspondents are informed that we cannot undertake to answer com- municalions through the post. •,* Communications relating to Advertisem/ints and general business affairs should be addressed to Messrs. Henry Greenwood & Co. , ii York-street, Covent Garden, London. ■*^* It would be convenient if friends desiring advice respecting apparatus, faitures in practice, or other information, would call at the Editorial Office either on Wednesdays from i to 6, or Thursdays from 9 to 12 noon, vihen some one of the MditwuU staff will be present. Constant Reader. — You omitted to give your name. Knowledge is Power ; A. J. ; and others, in our next. Accessories. — Mr. W. H. Redshaw, of Bourne, Lincolnshire. G. Wright & Co. — Why not adverti-^e the solution for that purpose .' JEbor. — Apply to Mr. W. I. Chadwick, St. Mary's-street, Manchester. Xux. — The simplest and, in the end, the cheapest plan will be to purchase a new dish. W. M. — It is doubtful if the stains can be removed, dilute hydrochloric acid, or, failing that, oxalic acid. Try the effect of very G. Reynolds. — Yes ; the chemicals are measured out by avoirdupois weight — sixteen drachm3,;of twenty-seven and a half grains each, to the ounce. T, Ray.ment. — So SJ- as we are aware the collodion transfer for the so-called " Club Picture " is extinct. Therefore, if you must have them, we suspect you will have to learn how to make them for yourself. Spots. — ^We know seve^i ways by which the stains may be taken out, but none that will remove them without also removing or changing the colour of the fabric, so that the remedy would probably jjrove nmcii worse than the disease. R. T. Watson. — The best way will be to obtain instruction from a practical worker of the process. If you desire to work the process as a business, the best way will be to "article" or apprentice yourself to some of the firms who take apprentices, and many do. E. Hopper.— A portable studio such as yon desire will be constructed by any of the horticultural builders in your neighbourhood. If you require one second-hand, no doubt an advertisement in the columns devoted to such puqjoses will secure what you desire. E. R. Newman. — Whether the emulsion was defective or not we, of course, cannot say. The negiitive sent (which arrived in fragments) was not sharply focussed, which may in some measure account for its apparent lack of detail. Its appearance is not inconsistent with over-exposure. •E. Walton.— Your friend is quite right, the boiling point of water is 100", but that is on the Centigiade scale. On the Fahrenheit scale, with which you are familiar, it is, of course, 212°. On the Reaumur scale, the boiling point of water is 80°. The latter is the scale most used in Germany and Austria. 'H. R. P. a.'iks : " Can I, as an amateur photographer, let photographs of mine be .sold for a charitable purpose, thereby receiving no benefit for myself, without infringing the laws for exhibiting as ail amateur. Kindly answer this."— This query is on all fours with that put by C. Moore, and the reply will apply in both cases. Each of these correspondents appears to be anxious not to lose the privilege of being bond-fide amateurs. C. E. CoE writes : "Will you please answer the followimc : What is the best way to vignette bromide paper and opals, by artificial light, when printing in contact ? I have tried several dodges, but up to the present cannot get a reliable result."— Ma.sk the negative as in silver printing— that is, with it placed some distance from the negative— and keep the frame moving during the exposure, so that the light is diffused between the mask and the negative. Bromide. — 1. If the manipulations as described were carefully carried out, there ought not to be any spots at all. Obtain a fresh batch of paper and compare with the old. 2. If the glasses be clean, and are in goo PRESIDENTS ADDRESS 4^ "OS A FAILURE OF THE LAW IN PHOTOGRAPHY THAT, WHEN THE ■ PRODUCTS OF THE INTENSITY OF THE LIGHT ACTING AND OF THE TIME OK EXPOSURE ARE KyUAL. EQUAL AMOUNTS OF CHEMICAL ACTION WILL UE PRODUCED.' By CAPT. W. DE W. ABNEV, C.B., K.R.S... 422 PlOl MY FIRST DAGUERREOTYPE. By VALENTINE BLASCHABD 4i3 DODOES. By C. O. OBEOOBY 444 NEWS AND NOTES 4»5 HBETINGS OF SOCIETIES 440 FORTHCOMING EXHIBITIONS 487 RECENT PATENTS 487 correspondence 417 EXCHANGE COLUMN 481 ANSWERS TO C0BBESP0NDENT8 4S2 THE BRITISH JOURNAL OF PHOTOGRAPHY. No. 1732. Vol. XL.— JULY 14, 1893. RA.TIO OF GRADATION. Mr. Bothamley did good service at the Convention in en- deavouring to remove what might not inaptly be termed the deadlock on this question between highly skilful scientific theorists and skilful practical workers. He disclaimed any in- tention to introduce new facts into his lecturette, but led his hearers into paths from which they could look at old facts from different standpoints. He pointed oat that, while it was patent that in this gradation question photographers appeared not to agree, it yet might turn out they were talking really of different things when they imagined they were discussing the aspects of one only ; and he did not hesitate to point out the folly of using loose nomenclature in discussing scientific re- sults. He strongly accentuated the fact that nothing that Messrs. Hurter & Driffield had written was contrary to the contention of practical men that the printing value of a nega- tive was greatly under control. Messrs. Hurter & Driffield, rn their valuable researches, required to discover the relation that existed between the amount of silver deposited and the amount of light to which it was owing. Put into simple language, their experiments, in their view, go to prove that, if a certain amount of light results in a certain amount of silver being reduced, twice as much light will give twice as much silver, and so on. By means of two simple diagrams, representing a set of four gradations, Mr. Bothamley showed how the printing value of a negative might be vastly improved by altered development, and yet the proportion or ratio exist- ing between the highest, the lowest, and the medium tints remain the same. Some difficulty was felt in accepting to the full his valuation of the important position as regards the ratios held by fog. Fog, he pointed out, was rarely, if ever, absent from a negative. The typical perfect one, with "absolutely clear glass in the shadows," rarely, if ever, was: absolutely clear glass in the shadows, and this would be readily seen by placing the plate upon a piece of white paper. To every one conversant with mathematics it is a truism to state, that, by adding to each term of a geometrical ratio, the ratio is altered. If fog deposit be added to the light deposit, ihe ratio that wo\il(l be obtained by a fog-free plate is interfered with, and the printing value may positively be a function of actual fog. When a plate is over-exposed, and it is said that the ratios are altered by the usual mode of counteracting over-e.xposure, Mr. Bothamley pointed out that what happened Wiis that all the alterations worked for less fog, while with under-exposure the correcting methods introduced fog. A great part of the interesting discussion that followed turned upon this view. Mr. Cowan, while quite ready to believe that he was not really at issue with the lecturer, claimed that fog had not the influence claimed for it. Dr. Mitchell, Mr. R. H. Worth, and Mr. Watmough Webster joined in the discussion, the latter gentleman introducing to notice what he considered a neglected factor in fog valuation. Messrs. Hurter angle of from 30° to 40°, and the board be set in even motion, the gradation will be as perfect as in diftused light. But it must be borne in mind that any irregularity of motion or de- parture from the horizontal will, with a fixed] light at close quarters, produce a corresponding want of uniformity in the gradation. A further means of softening and equalising the gradation by whatever means obtained consists in interposing a sheet of tissue paper or ground glass midway between the vignetting screen and the negative in such a manner that the intervening screen itself becomes, in a measure, the illumiuant. This, of course, gives much greater softness, though it necessarily in- creases the exposure. A simple frame of three-eighths of an inch in thickness, to fit in to the front of the printing frame, will suffice to carry the tissue paper on one side and the vignetting: screen on the other, and can bo made attachable to any frame. Some little more attention might well be given by dealers in this country, as is the case in America, to the provision of special frames and appliances for vignetting, and more especially for vignetting bromide and other films that necessitate the- use of artificial light. . ^ The Chlcagro Exhibition.— We learn by a telegram just received that the Judges appointed to make the awards to the- exhibitors are to commence their labours to-morrow (Saturday). It is to be hoped that they will prove satisfactory to all concerned.. Anyhow, exhibitors must be better satisfied to have their works- adjudicated upon by a jury than reported upon by any single indi- vidual. Had this system been adopted in the first instance, much) unpleasant friction would have been avoided. The " Benevolent."— During the outings of the Convention last week, especially when these took place on a steamer, Mr. Hedley Smith rendered excellent service to the Photographers' Benevolent Association by going frequently round with the contribution box. After a song, say hy Mrs. Mason, W. D. Welford, Birt Acres, or others, off on his rounds among the passengers would start Mr. Smith, whose appeal for the " smallest donation " was seldom disregarded. In this way the goodly sum of five pounds was collected and handeds over to the President of the " Benevolent." Gold. — A great many professional photographers prefer to make- their own chloride of gold, and usually, notwithstanding it is illegal, employ the current coin of tlie realm for the purpose. From a return just made, it appears that no less than 1(5,000,000/. worth of worn, gold was withdrawn from circulation last year. In making the chloride new coins should always be selected. This should be mani- fest to every one ; hul we recently saw some about to be used which,, upon being -weighed, showed a deficiency in weight of several grains in the bulk. New sovereigns cost no more than worn ones, and they yield more chloride. ^^^^^^_^_______ An Incomplete Novelty The Literary World, alluding to. an American work, Titled Americans, which gives a Ust of Ame- rican ladies who have married titled Englishmen, and some of those who have married titled foreigners, says : " The most remark- able feature of the book is the list appended of the unmarried scions- of our nohiUty, with their estimated incomes— a sort of vade mecum for Chicago miUionaires." Surely, such a work would be far more complete if it were illustrated with the portraits of the titled bachelors and widowers. We imagine there would, in some instances, at least, be no difficulty in obtaining them if the object were ex.- plained. Here is a hint to further " American tn erpiise." July 14. 18»M] THE BlUTISH JOUKNAL OF PHOTOGRAPHY. 43« The Royal Academy.— A ro.solution has been submitted to the Council of this body, and has been discussed by it, accordinjf to which Academicinns and Associates will have to limit the number of 'their exhibits at the annual show to six, while outsiders are not to send in more than four. This, if the resolution be adopted, will con- siderably lij^hten the labours of the committees of selection, while it may induce some artists to concentrate their energy on fewer [works instead of expending them on a larger number, sometimes at the expense of execution. Would not some such regulation with regard to photographic exhibitions be an advantage, particularly some of those held in provincial towns and the suburbs of London? In many instances an exhibitor would figure to better advantage by showing half-a-dozen pictures than he does by exhibiting twice or thrice that Dumber. The Silver Market.— Photographers are less directly inter- ested in the value of silver now than they were formerly when the nitrate was required for baths in the collodion process and for sensi- tising paper. Now the silver nitrate is rarely required, if at all, by many photographers. Still, the market value of the metal largely •concerns dry-plate makers and those who supply ready-censitised paper. Silver has been depreciating in value for many years past, and the announcement of the lowest record has often been made. The record lias, however, again been broken, for a fortnight ago it was quoted at 29Jrf. per ounce. About five-and-twenty years ago it stood «t something over (lOrf. per ounce. The market lias recovered some- what, but is still in a very excited condition, and the value of the metal has fluctuated as much as ."ieveral pence an ounce from dav to day. Unless the new regulation with regard to the Indian mint be relaxed, or more mines are closed, it is clear that even the present price •of silver will not be maintained for any great length of time. Show Cases. — In connexion with the lack of enterprise shown by some portrait photographers, we have on more than one occasion commented upon the small attention given to the specimens exhibited in the show cases and shop windows. These are shown to attract sitters, and therefore, one would think, should be in keeping with the times. To exhibit portraits in summer attire when the snow is upon the ground, or in heavy winter attire during the dog days, is certainly a mistake from a business point of view. We were forcibly reminded of this one day last week, when the thermometer was registering over 80° in the shade. While admiring some excellent pictures in a show case in one of our fasliionable West-end thorough- fares, we overheard one young lady remark to two others, "Just look at those people in furs ! Ugh ! how horrid ! " Furs in photographs are always effective, and there is little doubt that the same pictures would be looked at by these same people with admiration a few months hence. With ladies the immediate style and fashion tell for much. Soyal Cornwall Polytechnic Society's Exhibition. — The sixty-lirst annual Exhibition of this Society will open at Fal- mouth on Tuesday, September 5, 1893. As heretofore, medals and prizes are offered in various departments, including photography, the •class being open to professionals and amateurs, and a section being •devoted to photographic apparatus. List of prizes and all further information may he obtained from the Secretary, Mr. Edward Kitto, F.R.Met.S., the Observatory, Falmouth. Information respecting the •photographic department may be obtained from Mr. W. Brooks, Laurel Villa, Wray Park, Reigate (member of the General Com- mittee). Medals are offered by the Society for meritorious produc- tions in the following subjects: — Outdoor photography (professional) : 1. Landscape, not less than :20xl6 inches. 1'. Landscape, 12x10 inches, and under. 3. Genre. 4. Architectural (exterior), -j. In- stantaneous, including marine. 6. Animals. 7. Enlargements. Indoor photography: 1. Portraits, not le.?s than 20x16 inches. 2. Portraits, 1.5 x 12 inches, and under. .3. Home portraiture. 4. Still IlLfe, flowers, &c. o. Interiors, architectural or otherwise, 6. Photo- micrographs. 7. Enlargements. Amateur: I. Landscapes. 2. Aichitectural, exterior or interior, '-i. Hand-camera work, not less than twelve examples. 4. Instantaneous, including marine. 6. Still life. C. Enlargements. The Aoyal Wedding:. — Probably on no previous occasion in a single day were so many plates exposed, and with so little reralt, aa on the day of the marriage of the Duke of York and the Princess May. We are told by dealers that, at the beginning of last week, there was quite a run on the most rapid brand of plates of the various makers of the quarter-plate size. The day, as far as light was con- cerned, was all that could be desired, and hand cameras were to be seen at all points on the routes of the processions. Yet how dis- appointingly small is the proportion of really good pictures that were secured as compared with the attempts made ! \ large number of novices have by now realised the fact that obtaining even fairly good negatives of events, such as that referred to, in the streets of London is by no means easy of accomplishment. Where there is a large crowd of people packing a thoroughfare, with high buildings on either side, there is always a considerable amount of haze and dust, which brilliant sunlight makes painfully conspicuous, that quite obUterates distance, though that may not be far off, unless there is a strowr wind blowing. It is this that has caused so many of the negatives to appear fogged when developed. However, many of the negatives obtained, though they may not be good photographically, will serve as interesting souvenirs of the occasion in time to come to those who took them. PHOTOGRAPHIC CONVENTION OF THE UNITED KINGDOM.* On Wednesday morning the General Meeting was held at 10 a.m., the President in the chair. Mr. Cembrano read the minutes of the last meeting, which were approved. He then read a list of societies which had sent delegates. These included the following : — The P/ioto- ffrajMc CM, J. Guardia and S. H. Fry ; Richnond Camera Club, R. L. Kidd and P. Ennis ; North London Photographic Society, J. Traill Taylor; Leicester Club, J. Porritt; Munster Club, Major J. D. Lysaght; Mandiester Society , 3 . Brier and E. Woodward; Tooting Club, Mr. L. E. Morgan ; London and Provincial Association, W. D. Welford and S. H. Fry ; The Photographic Society of Ireland, A. Wanier. There were also a large number of other ladies and gentle- men present from all parts of the kingdom, among the latter, not members of the council, being Messrs. J. W. Webber, Bromley; A. Iladdon, Greenwich ; Birt Acres, Barnet ; W. M. Ashman, Bath ; J. S. Hawke, Plymouth; E. J. Ilumphery, London; F. W. Hindley, London ; and E. Marlow, Birmingham. On the proposition of Mr. C. 11. Rothamley, the General Committee with the addition of a few fresh names were re-elected. Invitations from the Photographic Society of Ireland to hold the next meeting in Dublin, and from the Shropshire Camera Club to nieet in Shrewsbury were submitted to the meeting. A vote having been taken, it was declared that a large majority was in favour of Dublin. The President then asked the meeting to accord a very hearty vote of thanks to the Mayor of Plymouth for his most generous reception of the Convention, to the Plymouth Institution for the loan of their premises, to the Local Committee • for all they had done to make the meeting pleasant, and to the leaders of the excursions. If Tuesday's excursion might be taken as a sample, then they had a store of interest and beauty to come. Of course, the weather could not be commanded, but, inspite of the thunder and lightning and the torrents of rain, all managed to enjoy themselves, and the little sing-song in the saloon was by no means the least enjoyable feature. A cordial vote of thanks was given Mr. Cembrano, the Hon Secretary ; and Mr. C. H. Bothamley, in proposing it, said the pro- spects of the Convention had never been so bright, and that was due largely to the efforts and tact of their 1 Ion. Secretary. Mr. Cembrano, in acknowledging the compliment, said with this meeting his first year's service came to an end, and he was pleased to say that, for the first time in the history of the Convention, there waa * Continued from last namber. 43G THE BRITISH JOURNAL OF PHOTOGRAPHY. [July 14, 1893 a balance on the right side. (Applause.) It amounted to l-V. I9s. Qd., and next year he hoped it would be doubled, although the number of members was certainly a good deal less. So far he had received sub- scriptions from US, which was a good deal more than he expected, considering the great attractions in other parts of the country this week. Messrs. John Howson and S. B. Webber were elected auditors. The following motion, submitted by Messrs. II. Snowden Ward and E. J. Wall, was recommended by the Council for adoption :— " Resolved, that the Photographic Convention of the United Kingdom acknowledges the courtesy of the Photographers' Association of America in inviting British photographers to attend its Conference this year as honorary members, and this Convention wishes its Com- mittee to add to its rules one to the following effect:— That all members of the Photographers' Association of America be considered honorary members of the Photographic Convention of the United Kingdom, and, if travelling in the United Kingdom at the time of the Convention, are invited to take part in its proceedings." Mr. Wall, in proposing the adoption of the motion, regarded it as a first step towards a Photographic International Union. The Hon. Secretary seconded the motion, remarking that he had received courteous and encouraging messages from the Photographers Association of America. The motion was carried unanimously. Mr. J. Traill Taylor, whilst in full accord with the desire to culti- vate brotherhood with their American brethren, would point out that some of their brethren at home had a feeling of soreness towards the Convention, and th.it others regarded it with apathy. When the Convention was at Birmingham a debt was incurred, not perhaps wisely, and doubtless without due authorisation, by the brethren there, but in the interests of the Convention. Some, and he himself among them, looked upon this as a debt of honour, and he would suggest that, now the Convention had funds in hands, the Council should try to defray that debt as soon as possible, and thus remove the feeling of soreness, and also to overcome the apathy of places like Manchester. Mr. Taylor's suggestion was adopted. It was moved by Mr. A. Werner, and seconded by Mr. H. M. Smith, that the following be elected members of Council for the ensuing year: — F. A. Bridge, Dalston; J. J. Briginshaw, London ; C. H. Bothamley, Taunton ; A. A. Carnell. Plymouth; A. Cowan, Southgate ; J. P. Gibson, IJexham; M. J. Harding, Shrewsbury; II. M. Hastings, West Kensington; A. L. Henderson, London ; T.C. Hepworth, London ; R. Keene, Derby; J. A. King, Bath ; W. Lang, jun., Glasgow; P. Lange, Liverpool ; A. Levy, London; C. Phipps Lucas, Kent ; A. Mackie, London ; W. W. Naunton, Shrewsbury ; J. Porritt, Leicester ; A. Pringle, Bexley Heath; B. J. Sayce, Liver- pool; A. Seaman, Chesterfield; H. M. Smith, Stroud Green; J. Stuart, Glasgow; H. Sturmey, Coventry; J. Traill Taylor, London; A. Tate. B^lfan ; L. Warnerke, London ; G. W. Webster, Chester; J. B. B. Wellington, London; A. Werner, Dublin; R. H. Worth, Plymouth ; F. P. Cembrano, Richmond ; E. Appleby, Bath ; J. L. Lyell, London; E. G. Humphery, London; J. Fergus, Largs; W. Taylor, Leicester: R. L. Kidd, Hampton; T. Mayue, Dublin; and , Major Lysaght, Queenstown. At noon the official Convention group was taken in the Guildhall- square by Mr. Heath, of George-street, Plymouth, and the President announced, in the course of the afternoon, that the negative had turned out very satisfactorily. Mr. Scorer, of Havant, also took a group on a plate 28x20 with a camera that would take a plate 30 X 24. Numerous other " shots " were had at the group, one by Mr. Kidd, giving a fine picture which will be presented to our readers next week. Wednesday Evening. This evening the Slajor of Devonport (Mr. Alderman W. VV aycott), along with some of the Aldermen and Councillors, together with Mr. Croydon, the Vice-President, Mr. C. H. Moore, the Secretary, and with other members of the Devonport Camera Club, received the members of the Convention. The President of tlie Club, Colonel Stewart, was unavtiiably absent on duty in another part of the country. The Mayor s iJ it gave him muc'i pleasure to offer the Convention a hearty welcom'>, especially in their Council Chamber, whose walls were adorned with interesting examples of the photographic art taken by a former official of the Corporation, Mr. C. B. Rowe, their late borough librarian. It was with regret that he saw that the Con- vention excur.-ion up the River Tamar on Tuesday was sadly inter- fered with by the rain, but he hoped fair skies would favour them during the rest of their sojourn, so that they might see in tlieir fullest glory the beauties of the district of which the residents were so proud. They would, doubtless, be interested in knowing that at Devonport was born Robert Hunt, one of the earliest and most pains- taking investigators of the principles and chemistry of photographic operations. He apologised for the absence of the Town Clerk, who was on a holiday, and of several members of the Council, who were busy preparing for the Royal wedding celebration on the morrow. The President, in a genial speech, acknowledged the heartiness of the Mayor's welcome, and said it was an added pleasure to know that they were assembled in the birthplace of Robert Hunt, to whom photographers owed so much. Mr. C. Croydon then, in the absence of Colonel Stewart, the President, offered the Convention a hearty welcome on behalf of the Devonport Camera Club, paying a tribute to the memory of Robert Hunt, with whom was associated John Towson, another Devonport man, so well known as the originator of great circle sailing, mention- ing that Colonel Stewart was the inventor of tlie Panoram camera, and graphically illustrated the great uses of photography in astronomy, microscopy, and natural history. 3Ir. A. Tate, J.P., of Belfast, acknowledged the Club's welcome of the Convention, remarking that everywhere in the district they had been received with kindness and cordiality, and, in allusion to Mr. Croydon's remark, said photography was now the trusty handmaid of every science, seeing more than the eye of the astronomer, the physician, and the naturalist. Wines, tea and coffee, and other light refreshments were then served, and an adjournment was made to tiie Town Hall, where a most interesting optical lantern exhibition was enjoyed. Following this was a lecture, copiously illustrated by the lantern, by Mr. J. T. Cunningham, M.A., of the Marine Biological Laboratory, Plymouth, descriptive of the developments of soles, crabs, jelly-fish, and of the habits of the angler tish and the hermit crab. A paper on the Special I'ropertirs of the Zeiss Anastiymatic Lenses, by Dr. Paul Rudolph, with diagrams and specimens, was taken as read. A lecture on Photography in Relation to Medical Record and Demonstration was down on the programme to have been delivered by Mr. Andrew Pringle ; but, owing to the absence of that gentleman from illness, it was not given. Thursday. This day was devoted to a most enjoyable excursion to the ancient town of Totnes, and thence down the Dart to Dartmouth. The party, nearly seventy in number, started from Plymouth shortly after nine o'clock in the morning, and Totnes was reached about ten o'clock. The town looked gaj* with many Hags, while in the streets were people, young and old, in holiday dress, making ready for the festivities. The keep of the old castle was ascended for the view, and many pictures were taken of the gate in Fore-street and of the church, whilst a score of photographers all in a row were seen intent on making pictures of the well-wooded island. Ere Totnes was left the- children assembled on the Plains and sang the National Anthem,, and some snap-shots of the scene were taken from the pedestal of the monument to Wills, the Australian explorer. Most enjoyable was the trip down the River Dart. It was made in a steam launch, and a roomy boat and two smaller ones towed by the launch. The English Rhine, with its grand woods sloping down to the water's edge, and with its many windings, was seen at its best. Lirtle could be done photographically on the way down, but the hand camera was in constant use as soon as Dartmouth Harbour was reached. J3y H.M.S. Britannia, naval cadet training ship, the launch went slowly, that photographs might be taken ; then at grt ater speed the party proceeded to the harbour's mouth, to view the castle so picturesque!}' situated on the shore. Yachts, some dressed rainbow fashion and others in full sail, the Kingswear horse ferry boat, and the high banks, with beautiful residences nestling among woods and gardens, and the castle itself weie t':e oirstant objects of member^' tittentim. Retu-ning- July 14, 1898] THE BRITISH JOURNAL OF PHOTOGRAPHY. 487 from the harbour mouth, the party landed on the quay, and, pro- ceeding to Bodley's Hotel, enjoyed a substantial luncheon, after which the President, in sympathy with the feelings of tlie company, gave expression to the hope that the Duke of York and his bride would be blessed with a long and liappy life, and heartily thanked Mr. Barnston for acting as leader of so interesting an excursion. Then the party separated to photograph the Butter Walk (in one of the quaint houses of which King Charles If. held court), the Church of St. Saviour, scenes in the harbour, and the softening effect of a sea fog which drove over the hills above the town was seen. All were agreed that the borough and its land-locked harbour was truthfully described by the Queen on one of her visits as " Beautiful Dartmouth." The return to I'lymouth was by train, n'd Kingswear and Newton, Torbay and Torquay affording charming views in the bright sunlight. In the evening then- was a fair gathering at the Plymouth Athenaeum, when >Ir. Bothamley gave an address on Some Points in Connexion with Deiel'jiment, on which Mr. G. W. Webster, Mr. A. Cowan, and others made remarks. Other papers, on The Power of CompentaHnr/ in Development, for Variation in Krposure, by Professor W. K. Burton ; Latitude of Exposure and Speed of Plates, by Dr. F. Hurter ; and Our Pictorial Failures, by the Kev. F. C. Lambert, M.A., were taken as read. The members then adjourned to the Hoe, to witness the great pyro- technic display (including the burning of a ship) in connexion with the Royal Wedding celebration. Friday. There were three excursions this day, respectively to Lydford, Bickleigh Vale, and Dockyard and Keyham, Cattewater. The annual dinner was held in the evening, and was numerously attended, many ladies, as usual, being present. The toast hst, which was laudably limited, comprised the Queen and the Royal Family; and The Convention, proposed by the Presi- dent, was responded to by Mr. R. H. Worth, local Hon. Secretary, and Colonel Barrington Baker, who then, in the name of the I'lymouth Club and in a few fitting remarks, presented the Club's medals to Mr. Mason, President, and Mr. Cembrano, Secretary, as a memento of the Plymouth meeting, both of whom acknowledged the graceful gift. Songs, speeches, and recitations were contributed by Mrs. Mason, Mrs. (Dr.) Mitchell, Messrs. A. Cowan, S. H. Fry, A. Werner, C. H. Bothamley, G. W. Webster, A. Tate, Fuerst, Laurence, Welford Newman, and MowU. The dinner, taken all in all, was a great success. Saturday. A meeting of the Council was held this morning to elect a presi- dent. 5Ir. J. Traill Taylor said that, as the meeting next year was to be held in Dublin, it was fitting that a representative Irish gentleman should be elected. The name of Grubb had for a long course of years been honourably connected with photography, both through the father, the late Thomas Grubb, and the .son. Sir Howard. He therefore begged to propose that Sir Howard Grubb, F.R.S., be elected presi- dent for the next year. This was seconded by Mr. Alfred Werner, who observed that Sir Howard's high position in Dublin would ensure the success of the Convention. This was carried by acclamation. A telegram was'received from Sir Howard, accepting the position. This terminated the proceedings. THE CONVENTION EXHIBITION. We now give a more detailed account of the exhibits :— Messrs. Jlorgan & Kidd.— We have referred to the large portrait of the lady which occupied the place of honour in the room. It was trimmed down to 8 ft. by 4 It., having been taken G ins. larger both ways. It was supported by two large portraits of a lady and eavalier, somewhat inferior in dimensions, but equally excellent in technique. Pictorially speakirg, Mr. Kidd's Mixty Mominy, an enlargement from a hand-camera view taken on the return journey from the Edinburgh Convention last year, was probably the best land- scape in the room. Their works in carbon challenged attention, especially a portrait of a lady seated in an ornate chair. Several of these were nicely coloured. They had also a fine exhibition of works in collotype, a department into which this firm is now going extensively. Mr. Heath, Plymouth. — Among this artist's exhibits was an " At Home" portrait of H.R.H. the Prince of Wales; also portraits o( their R.H. Princesses Marie Victoria and Alexandra of Edinburgh. There were also various carbon prints. Messrs. Elliott & Son, Bamet. — A singularly fine portrait of a lady, enlarged from a negative by Werner & Son. This was a direct print in carbon, produced from a plate of the krge dimensions of 04 x 38 inches. .Air. .fohn Hawke, Plymouth. — This artist's exhibit consisted of a frame of eighteen portraits of H.R.H. the Duke of Edinburgh, which bore the announcement that they were from part of a series of thirty- one negatives taken in forty-two minutes. Mr. W. C. Tweedy, Plymouth. — This exhibit consisted of a number of views, some of them embracing an exceedingly wide angle They are entitled " Experiments in Panoramic Photography." Mr. II. Yeo, Union-street, Plymouth. — Mr. Yeo is evidently a master as regards the taking of children, of which this formed one of the most charming collections to be met with. Some are enlarged and are skilfully coloured. The Eastman Photographic Materials Company had an imposing exhibit which occupied one entire side of the room. The leading feature in their exhibits was soliotypes, plain, burnished, and enamelled, mainly in rich purple and black tones, and in every size from twenty- two inches downwards. The capabilities of solio paper have never before been so well illustrated. This firm exhibited for the first time specimens on their new Nikko paper. The tones of these are of a peculiarly warm and brilliant character. The various exhibits are from negatives by Lafayette, Dublin; Brown, Leicester; Yeo, Plymouth ; and several by American photographers. M. & T. Scott, Edinburgh. — Several excellent enlargements from negatives by Wameuke, Glasgow ; Hawke, Plymouth ; Ellis, London ; Heath & Bradnee, Exeter; and Villiers & Quick, Bristol. O. Sichel & Co., London. — Two good enlargements from negatives respectively by Byrne & Co., Richmond; and Cox & Durrant, Torquay. W. Scorer, Havant.— Direct prints of Netley Abbey and Portsmouth Town Hall, taken on plates .30 x 24 inches. The Sandell Plates were well represented by numerous scenes, groups, interiors, and other subjects, prominent among them being St. Mark's, Venice ; A lioyal Vinery ; Froymore ; Dean Stanley's Tomb, &c. Messrs. Benthall & Co. exhibited their ingenious simplex camera stand, of which we gave an account a few weeks since. Messrs. Geo. Houghton & Sons showed Clement & Gilmer's tele- photo lens in brass and aluminium, together with the well-known shuttle hand camera. Beale's Non-Actinine had a prominent place on the table, and the albums, frames, mouldings, backgrounds, and other exhibits of Sichel & Co. were well to the front. This last firm also exhibited a portrait camera for 15 x 15 plates, and an outdoor camera expand- ing to fifty inches. Messrs. Taylor, Taylor, & Hobson had appliances in the shape of a camera front fitted with flanges and lens moimt showing their system of perfect screw attachments. The new developers were in good display. Messrs. Fuerst, Leblanc, Morgan, and Haussmanu were present to impart informa- tion when required. Messrs. Geo. Mason & Co. showed a model of a singularly compact projection lantern, believed to be the smallest practical lantern that has yet been seen. The catalogue of this firm now forms quite a thick volume. The following are the papers that were read : — RECENT DEVELOPERS. Bt E. J. Wall. A WRITER in one of the journals lately said, " On what grounds and to what purpose this eternal pu£f of the most recent ? Is there a ' fashion ' in photography that we must all betake ourselves to the last haute nouveaute or proclaim ourselves slovens ? Amidol 1 metol ! glycin t These are ' the only wear,' and the old clothes are gone to the ragman I But snpposo that the old should be better ? " I think possibly in the last sentence we may find the reason why we have " this eternal pufl," or, I would rather say, this eternal experimenting with new things. I take it 438 THE BRITISH JOURNAL OF PflOTOGlRAPHY. [July 14, 1893 that there is a general feeling of a desire for progress, whether in technique or art, and that to this desire we must put down the craze for the last new developer, the latest lens, and the latest printing process. If some snch healthy feeling did not exist, photography would not have made the progress it has done in the last fifty years. To our professional brethren who, when working in the studio, may be said to work practically under given conditions, not the least of which is to turn out good work which shall remunerate him suitably for his skill, his time, and outlay, there is possibly not so much temptation to experi- ment, especially when experimenting may mean increased expense without any increase of revenue ; but to the amateur, to whom expense is possibly not so much an object, and who firmly believes that he may yet discover a panacea for all ills of under or over-exposure, or careless or ignorant working, there is a very strong temptation to exchange " old lamps for new." One of the subjects which has claimed no small amount of attention since our last happy meeting in Edinburgh is that of the new developing agents — amidol, metol, and glycin — and I propose to summarise the results of a few experiments which I have made. The number tablet of Wamerke's sensitometer was used as a con- venient subject to expose with. The light chosen was a Welsbach or incandescent gas burner, the supply of gas being passed through two governors to regulate as far as possible the supply. Commercial plates marked with one batch number and one speed number were bought, and exposed one after the other as quickly as possible, and then treated with the various developers. Mr. Bothamley's standard pyro-soda developer was used for the pyro to obtain a standard. The other developers were modified to try what was the effect of modifying the proportion of the constituents of the various chemicals. Amidol IS a salt of di-amido-phenol, and is fairly soluble in water, form- ing a slightly acid solution. It is far more soluble in solution of sodium sulphite, and with a saturated solution it is possible to get as much as sixteen grains of amidol dissolved in every ounce. The distinctive feature of amidol is that it forms a very energetic developer in conjunction with sulf)hite without the addition of an alkali, and for this reason alone I think it is worthy of consideration as obviat- ing any chance of frilling, which was not unknown with eikonogen and hydroquinone when used with caustic alkalies. The first method of using this developer, suggested by the makers, was to prepare a stock solution of sulphite and amidol, and dilute as required. Such a solution, however, has, I think, given rise to some of the contra- dictory statements we have heard about this developer, but it is now generally accepted that keeping it in this form is certainly not the best way of using it, and I have here a negative which fully bears out this idea. A plate exposed in a studio was cut in two, and part developed with a freshly made solution, the other part developed with a similar solution three weeks old. The difference is so striking as to need no comment to those who see it : the one part, that developed with fresh solution, is dense ; the other, developed with old solution, a veritable ghost. As amidol is readily soluble in water or sodium sulphite, there is not the slightest difficulty about making a solution up as required. Coming now to practical tests, I have tried the addition of varying quantities of sulphite, amidol, and bromide, and I will summarise the results I have obtained. The normal developer used was amidol, 1 ; sulphite, 10 ; water, 100. In this the image appeared in 10 seconds, and development was complete in 5 minutes. Increase of sulphite in the proportion of 15, 20, 30 merely reduced the time before the appearance of the image and the time of development, but when over 20 parts of sulphite were used the plates fogged very quickly. Increase of amidol also accelerates the appearance Of the image, and enables one to obtain density very readily, and I may here state that, with some plates I have tried, the amidol has to be increased to the extent of 10 to 15 grains per ounce before sufficient printing density could be obtained. Dilution of the developer with water delayed the appearance of the image, and tended to thinness of image, though this, of course, can be compensated for by developing longer. The addition of bromide in small q'"ntities— that is, up to about 1 grain per ounce of developer, seemed t. lave little or no influence, but in larger quantities to the extent of 8, J ., and 20 grains per ounce', the appearance of the image was enormously delayed, and, notwithstanding a development protracted to over six hours, neither density nor as many numbers could be brought out. So far, I think that a more certain and reliable restrainer will be found in the use of a weak acid, such as citric or acetic. - The influence of the temperature of the developer was tried as follows : A developer was cooled by means of ice till it registered 35* Fabr. In this the image appeared in ten minutes, and took one and a half hours to gain anything like reasonable density, and was then finally too thin. A developer of the same constitution was heated to 70° Fahr., and the image appeared almost the instant the developer touched the plate, and development was finished in two minutes, the plate being slightly fogged. I have here two negatives developed with amidol, kindly made for me by Mr. Beckett, of Hackney, as examples of ordinary studio work, and he says that negatives developed with amidol or metol do not require so much retouching as pyro-developed negatives, and, as he does the best part of his own work, he ought to know. I hand these round specially for the benefit of our professional brethren. Finally, it has been said that plates for development with amidol require less exposure than for pyro. This I cannot believe ; I have made a series of very careful tests, cutting exposures down, and I have not found that amidol will fetch more out of the plate, it will not fetch out what is not there, but what it will do is to flash the image up and give far softer results, which are more amenable to after-treatment than the harsh negatives so often yielded by pyro with under - exposed plates. It has also been recommended to use amidol in conjunction with metabisulphite of potash and an alkali. So far my experiments have only enabled me to obtain a filthy mess of a developer, and magnificent examples of dichroic fog, but I intend to try it with other plates, be- cause all plates do not require or stand exactly the same method of working. It seems to me to be absurd to suggest the use of an alkali when we can get such excellent results without it ; but Dr. Stolze suggests keeping a stock solution of amidol and metabisulphite, and then at the moment of using neutralising with bicarbonate, not carbonate of potash, but so far I have not been able to obtain better results with this than by dis- solving the amidol in plain sulphite just before use. Metol is the sulphate of methyl-para-amido-meta-cresol, and is a glisten- ing powder of faint buff tinge. It is soluble in water to the extent of two and a half parts — 100 of water. In solution with sulphite, it forms a colourless solution, which keeps its developing power, so far as I can see, unchanged, thus having the advantage of amidol in this respect. Like amidol, it develops without the addition of alkali when used with sul- phite, but the images are extremely thin and weak. The alkaline carbonates of potassium and sodium may be used, and of the two potash gives a quicker developer and rather more density, soda having a tendency to a slower development and softer results. Bromides act in small quantities merely by delaying the appearance of the image and prolonging development. I developed some plates with eight to sixteen grains of bromide to the ounce of developer, and with the latter quantity the image was twenty minutes in making its appearance, and, after six hours' development, only four numbers were rendered visible. In small quantities, however, bromides seem to have far less action than with pyro and some of the other developers. A normal developer may be considered to be one containing metol three grains, sodium sulphite thirty grains, carbonate of potash or car- bonate of soda fifteen grains to every ounce. If distilled water be used, there is no necessity to use so much sulphite, and I have not been able to detect that the omission of the sulphite has any ill effect on develop- ment beyond a slight tinge given to the gelatine. Increase of the alkali tends to produce harder results, that is, the higher lights are denser than the lower. Dilution with water produces greater softness, whilst increase of metol causes again greater density. Testing as to the influence of temperature, I found that at 35° Fahr. development was unduly protracted, and only thin images obtained, but in no case could I get a lower number, whilst heating the developer caused fog. I again tried with metol to see whether it brought out more than pyro, or, in other words, whether it permitted of a re- duction of exposure, and I am compelled to say that my results were distinctly contradictory to this statement. The main advantage of these two new developers is that within reasonable limits, in fact, I do not think I should be far out if I said it was impossible to obtain that hardness which is so easy to obtain with pyro and slight under- exposure. Glycin is oxyphenyl-glycin, and is a pinky, salmon powder, smelling strongly of carbolic acid, not very soluble in water, and more soluble in sulphite solution or an alkali, when it forms a colourless solution, which seems to keep well as a normal developer. I have used glycin five grains, carbonate of potash twenty-five grains, water one ounce,2and find that diluted with water or addition of bromide gives far more transparent July 14, 1893] THE BRITISH JOTTKNAL OF PHOTOGRAi»HY. 4.'i9 negatives. It is characteristic of glycin that it requires no addition of bromide in order to give negatives absolutely free from fog under condi- tions and with plates, that with amidol, metol, and pyro invariably gave fog. It is, in its action, I think, more like ferrous oxalate than any other developer, and should be useful for black-and-white work, and I have used it for this purpose with excellent results. I have not used it so much as metol and amidol, but am inclined to tbink it is less useful for landscape and portrait work than the others, though for plates over- exposed in the field I have obtained some capital results by using a very weak glycin developer, in the proportion of glycin one and a half grains, potash carbonate twelve grains to the ounce, and allowing plenty of time for development. Of these three new developers, I think the one that will find most favour is metol, because it is more akin to the older developers, in that it is used in two solutions with an alkali. All of them are applicable to bromide paper and transparency work, but I must confess thnt so far my use of them for this purpose has been so small that I am loth to say anything about them. Within the last two months yet another developer, reducin, has been announced, whicli, like amidol, requires no alkali, and it is quite possible that we are by no means at the end of our list yet, and that thanks to the energy and researches of our German friends, we may be blessed with still more tools to play with. I have, of course, condensed my remarks, and I have not brought down any experimental plates, though I had intended to do so, but I thought it would hardly interest you to look through between 1.50 and 200 nega- tives. Nor liave I in any case tried for what Messrs. Hurter & Driffield have defined ad a perfect negative. I have tried these developers from the same standpoint as a man in practice would use them, but I hope I have said sufficient to prove that it is worth while giving the new-comers a fair trial, even if it is not found that they will oust our dirty old friend pyro. Since tlie above was written, Messrs. A. <1- L. Lumiere's paper, read before the Societe Franvaise on June 2, has been published, and I briefly sammarise it. They suggest the use of the oxalate of di-amido-phenol as preferable to the chlorhydrate, which is one of the commercial forms of amidol, and the oxalate is formed by them by double decomposition of potassium oxalate and chlorhydrate of di-amido- phenol. The one is of course, well known to you all, and the latter is amidol Hauff : 20 parts of this dissolved in 200 parts of water, and mixed witli 19 parts of oxalate of potash dissolved in 200 parts of water gives a solution containing 21-5 parts of oxalate of di-amido-phenol. This salt is sparmgly soluble in water 1 in 2000, but far more soluble in sodium sulphite solution, and by means of this it is possible to get a concentrated solution. A 2 per cent. [solution of sulphite will dissolve IJ per cent, of oxalate of di-amido-phenol, a 5 per cent, sulphite solution dissolves 3 per cent., a 10 per cent, oj per cent., and a saturated solution 7 per cent. Messrs. Lumiilre state that increase of the strength of the di-amido- phenol above 3 per cent, gives no increase of energy of the developer. A very few drops of 10 per cent, solution of ammonia accelerates very much without giving any fog, but that with larger quantities of ammonia a general black fog is produced. A few drops of 10 per cent, solu- tion of acetic acid is the best restrainer, small traces of bromide having but little effect. Finally, they suggest the following formula for instantaneous work :— Oxalate of di-amido-phenol . Anhydrous sodium sulphite , Distilled water 5 parts. 30 to 40 „ 1000 „ For time exposures reduce the quantity of Bulphite to ten to twenty parts. The advantages of the oxalate salt are that both in the solid and liquid state it is more stable, considerably less sulphite is required, which, from an economical point of view, is not to be despised, and, finally, it will not stain the skin. I only received the number of the Bulletin containing this paper last Tuesday, and have not, therefore, had much opportunity of doing more than try the method suggested by Messrs. Lumiire, but I have tried it both with amidol-Hauff and amidol-Andresen, and find it certainly workable, and I tliink it will prove to be in practice an advantage, and for those who would like to try it I suggest the following rough-and-ready formula : — Dissolve 20 grains of amidol in J ounce of distilled water, add 80 minims of the normal 1 in 4 oxalate solution as used for ferrous oxalate developer, then add from 1 to 2 ounces of 1 : 3 solution of sodium anlphlte, decant or filter from any precipitate, and the developer is made. I had hoped to have been able also to make acme mention of the method of developing plates with gelatino-silver emulsions, as suggested by Dr. Jenney, which has appeared in several photographic journals during this last month ; but, whilst I have only just had time to concoct tlic awful mixtures suggested, and try them for about a dozen plates, I am unable to say anything for or against because of such few experi- ments; but it is certainly a promising field for experimentalists, and the process may prove yet another valuable assistant in practical work (or obtaining pictures. Mr. L. E. Morgan did not agree with the statements as to the reduction of exposure by means of amidol. If they were going to use amidol, the exposure must be reduced very much. Taking pyro as a standard, the reduction must be one half. Mr. Birt Acres found that with a very weak pyro developer he could get everything he desired. The negatives just shown appeared to him to be fiat. Mr, Cembrano thought that they could get a softer picture with pyro than with anything else. Dr. Mitchell said his impression was that the new developers at present offered no advantages over pyro. He felt there was a strong reducing power in them, however ; but, as yet, it was like the task of cliaining lightning to bring them down to the practical uses of photography. Mr. A. F. MowU thought they could not judge as to the printing qualities of the old and new developers, as one bad to be made more dense than the other. Mr. Sturmey considered that amidol should be used rather as an assist- ant to pyro than to its exclusion. The two combined had given him the best results he wished for. Mr. Henderson thought they were simply working in the dark with regard to new developers. The President was inclined to the belief that pyro negatives, if well worked, were to be preferred to any other. In replying to the discussion, Mr. Wall said the new developers had the advantage, that was much as it required a great deal of training and ex- . perience to get good results with pyro, anybody could succeed with the former. LANTEBN-SLIDE MAKING. By Charles L. Mitchell, M.D. The preparation of lantern slides is a subject upon which so much haa been both said and written within the past few years, that it would seem almost impossible to say anything new. And yet, notwithstanding this, the number of really good lantern slides made bears but a small propor- tion to the entire amount produced, or to the large quantities of plates, &c., used for their preparation. So that it seems, perhaps, after all, something might be still said on such a trite and commonplace subject. Having, during the past few years, occupied much of my time in lantern- slide making, I have acquired considerable familiarity with the different- methods usually employed in America, and also made some modifications' of my own, so that, while not pretending, in the limits of the present paper, to give a complete remm€ of the subject, it may be of interest if I detail, in a general way, the methods mostly in use by American lantern- slide makers. The vast majority of lantern slides made in America by amateurs' are prepared from gelatine plates, collodion emulsion being very little used, and wet collodion being employed by but few outside the regular com- mercial slide manufacturers. Perhaps this may be partly explained by a prevailing fondness for the black and grey tones, so easily obtained with gelatino-bromide emulsions. There is, however, a rapidly growing taste for warmer tints in brown, and even sepia, or Bartolozzi red. Quite a number of different brands of lanternsHde plates are found in our market, and of varied excellence. Of these, those prepared by the Eastman Company are probably the most popular. I have always used gelatine dry plates for preparing my own slides, and I am a firm believer that, all things being equal, it is quite possible to prepare as good, if not, perhaps, even a better slide upon a gelatine plate than can be obtained by any other procedure, while its convenience and readiness for im- mediate use render it much to be preferred. The size of the American lantern-slide plate is always 3J x 4 inches, thus differing from the English size, which is usually square, and 3J x 3J inches. We in America think the oblong shape the best, as it allows of a rather larger picture, gives ample room for the label, and also for taking hold of the slide when placing it in the lantern. We can hardly expect in a country Uke England, where customs are firmly established, that a change of size would readily be adopted. And yet it is highly desirable, in view of the growing interchange of slides between not only England and America but also with other countries, that some one standard and uniform size for all should be adopted. The presen difference often leads to considerable annoyance on account of fitting the 440 THE BRITISH JOURNAL OF PHOTOGRAPHY. [July 14, 1893 varying sizes into the carriers generally used for the lantern. This difficulty is less in America, however, than in England, for it is always easier to put a small slide into a large carrier than it is a large slide into a small carrier. I notice, indeed, that one English photographic periodical has announced that in future it will receive no slides for competiaon unless made of the uniform size of 3Jx.3J inches. This is much to be regretted, for it would seem possible iu such cases to use an ordinary " push through " carrier, and I hope the example will not prove contagious, for it will tend to check these international exchanges and competitions, and prevent many on each side of the water from becoming acquainted with the best examples of well-known workers. In the preparation of lantern slides I believe that the majority of our best workers in America prepare their slides by reduction in the camera. I have been informed that in England the reverse is true, the larger number being prepared by contact. I think this difference may partly be ascribed to the fact that the sizes of negatives adapted for contact print- ing m X 3| and 3J x 4^ inches) are not as popular in Americ i as they are in England. We do not use the SJ x 3J size at all, and for all small work the most popular size is 4 x 5 inches. This does not lend itself so well for contact work, and hence the reducing camera is more frequently brought into requisition. My own preference is unquestionably for reduction by the camera, even when preparing slides from small negatives. There seems to be a certain quality gained which is some- times missing in contact work, and, in addition, the process affords many facilities for shading or vignetting different parts of the negative which may need either holding back or prolonged exposure. The character of the light used is also another prime factor. In my own experience I use two different lights — a south light, where full sun- light falls directly upon a ground-glass window; and a north light, where the window is of clear glass and at an angle of about 45° to the horizon, thus securing an even, soft illumination all over the negative. I use one or the other of these lights, according to the character of the negative, as will be detailed later. Beturning again to the subject of lantern-slide plates, I may say that I do not believe it possible, when using all varieties of negatives, dense or thin, to obtain uniform excellence with one grade of plate. This would stand to reason, for a slow landscape plate will give a different negative from one made with an emulsion of high rapidity. I therefore use two grades of plates, one quite slow, giving great contrast, the other several times as rapid. In the former I use the Eastman plate, for the latter the transparency plate made by the Cramer Dry Plate Works, of St. Louis, Mo. These two varieties are used as follows : — Given a very strong, perhaps even harsh, negative, quite dense, and yet with plenty of detail. In order to bring out all the best points of the negative, a strong, intense light is required, and nothing but sunlight seems to answer the requirement. A weaker light will not penetrate the dense portions of the negative, and the corresponding parts of the positive will lack detail. Furthermore, the negative probably possesses too much contrast already, and the endeavour should be to reduce this contrast, and at the same time obtain all the detail possible. I therefore use here the fast lantern- slide plate, and fully time the exposure, using a diluted developer. The harshness of the negative is thus materially reduced in the positive, and the rapidity of the plate makes it more susceptible to the weak light coming through tlie dense portions of the negative, and thus renders the detail properly. Lantern slides made in this manner are usually quite warm in tone. Now, on the contrary, suppose a soft, thin negative full of detail, but with comparatively little density. Here the advantage of the slow plate and the soft north light becomes appaurent. This soft, even illumination is amply sufficient to penetrate any part of the negative, and yet, not being so intense as the sunlight, does not so rapidly overtime the plate. The slow lantern- slide emulsion is amply sensitive enough to render the detail perfectly in all parts of the negative, and with a moderately short exposure gives good contrast and brilliancy much exceeding that of the original. It is thus possible to obtain from an inferior negative quite a crisp and brilliant lantern slide. The tones obtained by this method are usually grey or black. For a developer, I use a mixture of eikonogen and hydroquinone in the proportion of fifteen parts of hydroquinone to eighty-five of eikonogen. Eikonogen by itself does not always give the brilliancy or the density desired, but this is easily obtained when a small percentage of hydroqui- none is added. The development of a lantern slide is an entirely different matter from that of a negative. In the latter, the time of ex- posure, and the intensity of the light, are always, to a certain extent, unknown factors, and the developer must be modified according to the necessities of the case. With the lantern- slide plate, the developer, as far as regards the proportion of reducer and alkali, is always the same, so alsa is the lighting of the negative. The developer should, therefore, be of a standard strength ascertained to give the best results with a normal ex- posure, and then, when making the exposure, it must be shortened or lengthened until the desired result is obtained. It will not do here to give a short exposure, and then push development by adding more alkali. The plate will soon fog, and an amount of fog which might perhaps be allowable in a negative would be fatal for a good lantern slide. Nor will it do to overtime, and then restrain development with a bromide, for we will be apt to get harshness, much density, and opacity in the shadows, all fatal defects for a good slide. What should be sought is a correct exposure, then a normal developer, and as the former is always under our control, it is better to reject a few plates and change the time of exposure until we have it just right, than it is to attempt to modify the developer. The question of tone here comes in for consideration. This is a matter influenced, first, by the plate, next by the developer, next by the character of the light, next by the exposure, and, lastly, by the negative itself. As I have before remarked, the cool grey and black-and-white tones are pre- ferred by many in America. There we use eikonogen, hydroquinone, ferrous oxalate, or pyro soda— all developers producing black or grey tones. The warmer tones in most of the slides made by English workers are, I am told, due largely to the use of pyro and ammonia as a developer. Still, for true warm tones gelatine can hardly be made to equal those ob- tained with collodion emulsion, either washed or dry. It is quite possible ^ however, with a strong negative, a sunlight exposure, a little over-timing, and a developer well diluted with water, to obtain quite warm tones with an ordinary gelatino-bromide emulsion. As far as regards fixing, there is nothing superior to the acid fixing bath, now so well known. It prevents staining and clears the plate thoroughly. The plate should always be varnished, to protect it from the effocts of moisture. I use for this purpose the "Zapon" varnish, a solution of nitro-cellulose in amyl-acetate and wood alcohol. As regards matting, the square opening, with rounded corners, is used by us for all commercial slides. Amateurs who make their own slides vary the opening, however, making it oblong, upright, oval, or round, accordmg to the artistic treatment of the picture. In labelling the slide, a thumb label is placed on the lower left-hand corner of the face of the slide, while the descriptive label is placed on the opposite end (right hand), sometimes on the face, but more usually on the back of the slide. Much might yet be said regarding the arrangement of the negative, apparatus for varying its position (so that either the whole or but a por- tion can be used , the choice of lenses, varieties of cameras for reducing purposes, Ac, but it would occupy too much time. The few extremely general remarks that I have made on the subject of lantern-slide making will, I trust, serve to indicate some of our most usual methods of working, and present, perhaps, one or two novel modifioatiens of the orthodox and regular modes of procedure. After some desultory observations respecting the relative advantages of the American and Enghsh sizes of lantern slides. The President said that, on a commercial scale, (he wet-collodion pro- cess was the only method by which uniform tones could be obtained. AETISTIC EXPRESSION WITH THE HAND CAMEEA. By J. GUABDIA. At this period in the history of photography, when every user of a camera is sorely puzzled to know whether his work is fine art or not, it seems to me useful, now we are assembled here, to pause a few moments and con- where we stand and whither we are drifting. While some writers claim for photography the highest artistic possi- bilities, others quite as strenuously assert that it is but a mere mechanical process, admitting of no variation in the hands of different workers, and therefore unworthy to rank as an art at all. Now, I think that the truth here lies, as is so often the case, midway between the two extremes, and that we should rather say that, though photography as generally practised is not an art, yet artistic expression is not impossible to photography. Further, if we admit, as I am afraid we must, that photography has not as yet realised its proper sphere as an art, we may at least hope that the day is not far distant when, acknowledging its limitations and under- stinding its possibilities, photography will at last gain an honoured place among the fine arts. But are we really doing anything towards this wished-for end? No, for the principles of art are order and culture, and in photography — in July 14, 189SJ THE BRITISH JOURNAL OF PHOTOGRAPHY. 441 the photographic world of to-day — nothing bat disorder and confusion, yes, and ignorance too, prevail. I am not now speaking of the great majority of people who " dabble in photography " — who go about the country securing pleasant mementoes of the places they visit, with the sole aim of amusing themselves and entertaining their friends. They are quite right in what they do, for, after all, they stick to what will always be the most popular side of photography — photography as n mechanical procegs, in which good appa- ratus and dexterity of hand are their own reward. Neither, of course, am I addressing myself to the select few (real artists at heart) who are, «ach for himself, earnestly trying te find a clear path out of the diffi- colties which photography is constantly setting before them. Their work bears the seal of their strong individuality, and is, therefore, truly artistic. But I am speaking of the general body of photographers, whom you may see at our clubs, who often write in our papers, who cram our exhi- bitions with their worthless productions. There is not one of them but thinks himself a born artist. But look at their work, and you will see no ait at all — merely a weak imitation of ^ome other art by means of photo- graphy. And this work is turned out in cart-loads, and is bemedalled by omnisapient judges, and crushes out any real pictures that may have strayed amongst it. What wonder that in the end artists merely laugh at us ! Our photographic world is chaos. We are all authors, publishers, and readers ; artists, critics, and judges. We elect scientists to decide weighty questions of art, and artists prattle about chemical problems. We all know so much that we are always quarrelling, and we only unite to bowl down any man who shows a little originality, and who strives to rescue us from our slough of despond. There are men abroad who, before they bought a camera, had never even stopped to consider that there was such a thing as art in the world, and who, probably, have not seriously studied a single word about it since ; but their fingers were deft, and they pro- duced negatives beautiful to look at, and which earned them a goodly show of medals. And, lo ! one day they issue forth past-masters in high art. Other foolish people, after years of deep study and constant work, hopelessly exclaim, " Art is long, and time is fleeting." Not so our facile photographer ; he masters it all in a few months. We clamour to be recognised as artists, but the bulk of the work at our exhibitions shows nothing but our absolute lack of taste. To select two samples only. Take first what we are pleased to call a " genre picture." How is it done ? You begin by placing the cart before the horse, i.e., by first selecting your title, and then looking around how to construct your work of art. Some figures are now more or less gaudily dressed and stuck in impossible attitudes before an impossible background, and the chef-d'aiuvre is accomplished. The result is applauded by the general run of photographers as a marvellous feat— a wonderful inspira- tion. To a person of taste such productions seem eminently absurd ; in fact, when they happen to represent historical subjects, the effect is often 60 incongruous that the authors themselves must at times feel ashamed of their own work. A particularly mistaken class of genre pictures is that which results from " double printing." Although this has enjoyed the advantage of being practised by some exceedingly clever people, their very best results have only served to prove that such tricks are entirely out of place in photography, and that nothing will ever be gained by these efforts to mimic methods which are legitimate and admissible in painting and allied arts only. Another proof, if one were needed, of the bad taste displayed by photo- graphers is to be found in the mounts they use. We need not mention the wonderful green and chocolate bevel-edge enamelled cards on which the professional fixes his perishable productions. No one has ever called the ordinary portrait-taker an artist, except himself ; but let us consider the mounts patronised by the " artistic amateur." Where could one find a more glaring proof of his incompetency to make photography a fine art than the " plate-sunk " mounts to which he consigns his efforts ? What on earth a plate-mark has to do with a silver or platinum print, I presume, BO one has asked himself. We have here a deliberate fraud — a confession on the part of the man that he distrusts the art he practises, and an attempt to make people believe that what he is showing them is not a photograph. This affectation is not art, and can do us no good. If a plate-mark is essential for our work, let us have real one ; let us print in photogravure. Fault-finding is an unpleasant task, and I do not intend to continue in this strain. I think, however, that what I have said may account to some extent for the contempt which photography is experiencing from painters and other artists, who should be, and may yet prove, her best friends. It seems to me that artists have not taken photography aeriously at all at yet, but how can we wonder at it when to the majority of photographers themselves a camera is only a plaything, and photography but a joke. My work of destruction having ended, I will attempt to explain the path which I think we shall have to follow when wc clearly undertand the nature of photography and her only true sphere of action as an art. That photography, an invention little more than half a century old, should have so quickly spread throughout the world, and should be prac- tised with equal enthusiasm by persons so different in temperament, position, or education, it must have something in its very essence which supplies a universal want, or gratifies some feeling which all civilised men share in common. The love of beauty in nature is more general than one is likely to suppose, and the very feeling which finds its loftiest expression in our great painters is but evolved from the unconscious efforts of primi- tive man, and, in fact, arises from tendencies inherited from our animal ancestors. As Professor Baldwin Brown so aptly explains: — " On every grade of his being man possesses an ideal sel^-determined life, existing side by side with, but apart from, his life as conditioned by material needs. This life expresses itself in, and is nourished by, various forms of free and spontaneous expression and action, which on the lower grades of being may be termed simply ' play,' but on the higher grades take the shape of that rational and significant play resulting in art." Now, I think we may readily admit that the success of photography is due to itj having given us an easy means to satisfy that desire for " play," that wish to forget the troubles of our daily labours which, as we have seen, is natural to us ; or to its having made it possible to everyone to express by his unaided efforts whatever artistic feelings he may have acquired through natural dispo- sition or education. The foregoing remarks, while explaining the wide popularity of photo- graphy as a pastime, give us no gauge of its merits as an art. That photography can be made an art we need not waste much time in assert- ing. As Nadar recently said : — " Why should photography not be an art, considering that, in copying nature, the painter, the draughtsman, the sculptor, and the photographer all aim at the same goal? Why should we trouble about the means employed if this reproduction of nature awakens in us the same impressions which we felt when looking at nature itself ? The superiority of the painter, the draughtsmen, and the sculptor would seem to consist in their power to create. But the use of the palette gives of itself no more right to the title of work of art to any reproduction of visible objects than does the employment of a camera. Photography is in itself a science and an art, and, above all, a means to an end. Its results essentially depend from the taste, the artistic know- ledge, and the temperament of the worker." In forming an estimate of photography as a means of artistic ex- pression, and in accounting for the unfavourable attitude which the general body of artists preserves against us, the enormous disadvantages which artistic photographers have had to contend, and are still contending with, should not be lost sight of. These are disadvantages which, in the nature of things, could scarcely be avoided in the early days of the new art, and which are now being rapidly overcome, and will, no doubt, soon entirely disappear. The principal difficulties which retarded photography in its progress as a fine art were — (1) The low sensitiveness to light of the materials employed, requiring long exposures, and (2) the inadequate nature and unmechanical construction of the apparatus used. The speed of plates has enormously increased within the last few years, and manu- facturers are even now vying with each other to turn out plates of greater and greater sensitiveness. With regard to a more correct rendering of the different colours, however, much remains to be done. Celluloid films also promise considerable advantages over glass plates, though they are as yet scarcely perfect enough for the best work. But it is the old apparatus which must bear the greater part of the blame for the low position which photography still occupies as an art. Lenses, it is true, have long been perfect enough, especially since the in- troduction of Jena glass. If the lenses generally used are of too short a focus, as undoubtedly is the case, the opticians are not to blame. In shutters, too, the photographer has been fortunate to secure the services of the highest mechanical skill, and though the modem shatter is a com- paratively new creation (called into life by the increased sensitiveness of dry plates), it is already, both in speed and efficiency, well in advance of the present requirements of photography. With cameras, however, the case is very different. Designed originally by incompetent persons, they have remained to this day the evident production of cabinet-makers and carpenters, whose only improvements during fifty years may be said to be the substitution of the shaky bellows camera for its steady but ponderous sliding-box ancestor, and the addition of simple movements, like rising front and swing back. The same type of apparatus has been adhered to, 442 THE BillTISH JOORNAL OF PHOTOGRAPHY. [July 14, 1893 not by a few, but by all makers, and this, not only in the early days when the slow processes employed demanded nothing better, but long after plates had reached a high degree of sensitiveness. For fifty years photo- graphers have had to carry about bulky implements, necessitating the use of a strong stand, and requiring long delays for setting them up ready for work. What wonder, then, that photography never reached its proper province among the fine arts— «/ie representation of life in nature, with all its beautiful but evanescent phases and movement, which has only now become possible, thanks to the modern hand camera. " Fine art," says Euskin, " is that in which the hand, the head, and the heart of man go together." What chance has the hand, the head, or the heart with a 15 x 12 field camera, and a tripod weighing five pounds ? Before hand cameras were invented, what was the aspect of nature as recorded by photography? A dead maze of trees, and fields, and build- ings. The rivers and lakes showed no ripple ; they were merely a mass of glaring white. The streets were deserted, and tenantless houses were but a mockery without reason. The beauty of cloud and atmosphere was nnknown— was represented by acres of white paper. Here and there a group of soulless caricatures of human beings were, indeed, to be seen, all stuck up in constrained attitudes. Not breathing, and moving, and palpitating with life and energy, but either blurred out of all recognition or fixed in unnatural poses, like wax dolls glaring at nothing — " puppets without muscles, and silhouettes without substance." Such was the world as depicted by the slow exposures of the old photography— an inane reiteration of topographical notes, or a spiritless multitude of lay figures in Sunday clothes. But, with the advent of the modern hand camera, all this has changed. The ripple on the water can be seen and almost heard ; clouds, fleecy or heavy, float across the sky; the elegant movements of the swiftest animals are recorded ; bustling crowds of men, women, and children are shown to us, picturesque in their ever- varying, unconscious attitudes in the course of their daily occupations, their toil, or their play. The tra- veller to distant countries will no longer bring uninteresting records of rains and desert solitudes, but animated pictures of the life, the troubles, and pleasures of the whole human race, from the tropics to the polar regions. A hand camera, ever ready, easy to carry, and able to with- stand all changes of climate and vicissitudes of travel, will help photo- graphy to outstrip the other arts in the representation of all the evanes- cent phenomena of nature, in making nations know and understand one another, in furthering the brotherhood and union of the human race. Useful to every one in indelibly recording what he sees, it will help the stay-at-home to portray his friends in familiar and natural attitudes, the traveller to bring back living records of his wanderings, the artist to show us nature as he sees it, deprived of its ugliness, and with its beauty enhanced. This, then, is the true sphere of photography as a fine art. Creation is impossible to us, let us therefore leave this to other arts. But ve still have the great power of selection, and of showing our good taste and artistic feeling. Let us cultivate this to the highest pitch we can attain, and employ it in the representation of life, and movement, and beauty of form in nature ; a field large enough, and one which the other arts cannot touch. We shall then be doing good and useful work — work that will live. The course which we should follow in our aim towards artistic perfec- tion is, I think, clear enough, but to foUow^it means hard work. Let us bo ti"ue to ourselves, always willing to learn from others, but doing what we honestly think right, whatever the uneducated multitude may say. Let ns study nature, for it is the fountain-head of all beauty. Let us cultivate art, that we may improve our good taste. There is no reason whatever why we should not photograph everything that interests us, whether it is a picture or not ; but let us acquire sufii- cient practice and knowledge to be able to see and secure a beautiful pose or subject whenever nature unexpectedly presents it to us in the course of our rambles. In order to do this with certainty, we must not only use good tools, but must gain great skill in using them. But let us never forget that tools and skill arejbut means to an end. I should like to see the day when a photographer only shows as pic- tures one ot tvio ol the very heit photographs he has taken during the year — when he does his utmost to make these as perfect as possible, by carefully enlarging them, if necessary, by printing, mounting, &o. Let us have exhibitions of such selected work, let it be judged by trained artists, and then we shall stand a chance of proving that photo- graphy can be made a fine art, for artistic expression is possible by means of the hand camera. Mr. E. Keene, alluding to;,the remarks about the plate marks in the mounts, considered that they were frequently a great improvement to a photograph. Mr. W. M. Ashman thought it might not possibly be known to Mr. Guardia that in former times streets could be photographed without being perfectly desolate. Skies also were not cloudless. Mr. Traill Taylor asked Mr. Guardia how long it was since hand' cameras were invented, in virtue of which such a revolution in artistic photography had been effected. Mr. Guardia. — Five years. Mr. Taylor appealed to Mr. Guardia, for his own sake and that ot accuracy, to strike out from his paper all those mis-statements about deserted streets, clouds and atmosphere being unknown, soulless cari- catures of human beings, with like statements equally devoid of truth, as well known to every one who was acquainted with the state of photo- graphy much longer than five years ago. Mr. Mowll, too, could not agree with aU Mr. Guardia had read. It required much greater intelligence and skill a few years ago than was imagined in these " press-the-button " days, and the work turned out- now was not better than it was then. Dr. Mitchell said that while artistic pictures can easily be made by the hand camera, much depended upon the man who was using it. Hand cameras were often very useful on account of their compressed bulk. After remarks by Mr. Birt^Acres and Mr. Fry, The President had to differ from Mr. Guardia, and alluded to the high art merit of the works of Wilson of Aberdeen, Wortley, and numerous others, produced long years before hand cameras were known. MULTIPLE FILMS. By S. Herbert Fry. The subject of compound or multiple-coated films is so new, and suppUes so many fresh ideas for practical work, that I cannot pretend in this paper to do more than deal in a touch-and-go fashion with it. My re- marks will only be valuable, if at all, for some practical suggestions as to the best methods of utilising the advantages which the principle of combining emulsions of differing characteristics and speeds into one film offers. Novelty. Although it would, perhaps, be safer to say that, for the preventioa of halation, multiple films in gelatine emulsions are rather the result of a happy thought than an entirely new idea, yet, as far as a practical manufacture is concerned, there is, I think, little doubt of their absolute novelty. Experimentalists may have drealmed of some such thing; as, indeed, of what have they not? but it has not hitherto- become a realisation. Still, we have in the old collodio-albumen dry plate a compound film consisting of a collodion bath plate with an albumen sensitised film placed on top of it, and one of our veteran workers, Mr. Forrest, of Liverpool, only a few days since, spoke to me most eulogisticaUy of thati old method, and hopefully of the multiple gelatine film for sympathetic reasons. That process is not only beyond my recollection, but probably there are few in this room who had any practical acquaintance with it. Manufacture. In making a multiple film dry plate, a coating machine may be said, to be necessary to secure a regular flow of emulsion for the second and third coating. With this exception there are no technical difliculties but. such as are common to the manufacture of dry plates generally. Each coating is dried before the next one is laid upon it, and the mos im- portant consideration for the emulsion-maker is to provide an emulsion, with as small a proportion of gelatine to silver salt as possible. Theory of the Film. In determining the relative speeds and characteristics of the different films a large field for experience and experiment is open, and time alone can determine whether the present an-angement is that best suited to attain the end in view. This may roughly be stated to be the nearest approximation to a single film in which the top surface shall be of the highest possible speed, and the bottom of the film of a density-giving silver salt, an emulsion slow and dense in the highest degree. The film should gradually change from one characteristic to the other. In theory the lowest portion of the film should perfectly resist the passage of actinic light. Bolas has, I think, referred to this point in some of his recent writings, and I take it to be the ideal of a sensitive film suitable for all purposes. Such a film, with our present knowledge, is not possible. We must be satisfied with the best substitute for it. I refer to this especially because it has been asserted that there are steps or jumps in the sensi- tiveness of a multiple-coated film which are ascribed to the difterence in speed of the various separate coatings. I do not propose to do more than allude to this for a simple reason. An examination of the pictures. July 14, 1893] THE BRITISH JOURNAL OJf PHOTOGRAPHY. 44S prodiicod by the films does not, I think, reveal any obvious faolt answer- ing to this criticism. I can conceive that, were a mnltiple film wrongly used, as, for instance, were the top film stripped off witli the idea o( securing a negative upon the lower film only, then, in such a case, there might be a lack of detail due to the removal of the top layer, and this might appear to be a jump in the sensitiveness between the two films. Such a method of working is not to be recommended, and I do not pur- pose to seriously consider improper uses of the film. It not infrequently happens that dangers or difficulties anticipated in theory do not occoi in practice. This is such a case. As to the part played by the underlying films, I regard them as pre- pared to take up and usefully employ such actinic rays as fall beyond the scale of correct representation in the overlying films. DiBIRlnUTION OF TUE ImAGE. Let us assume a case in which the range of contrast is great, such as a ^rk interior with a light and bright window. Let us also assume that which, I think, is generally the case, that for such a subject an exposure upon a dry plate is more or less of a compromise between the time necessary to properly photograph the deep shadows, and that necessary for the bright lights. Indeed, if it be not so, where is the difficulty in making such pictures? In the multiple film the image of the window will be formed upon the lowest film, and the middle tones upon the second film, whilst the details in the deep shadows will be upon the top film. In other words, the image will be distributed in a selective manner, and this can be easily demonstrated by stripping oS portions of the film of such a negative, and ascertaining the action of light upon the lower films. In the example given I have supposed that the exposure has been abnormal, that is to say, that the exposure has been made to act upon the sensitive material so as to sufficiently impress the details in the deepest shadow upon the top film, leaving the brighter portions to act selectively upon the lower and less sensitive emulsions. It is with such an exposure that the best value can be obtained from the multiple film. It is possible that, because better effects of light and shade are produced upon a multiple film by abnormal exposures, some have considered it a matter of necessity that such films should be, in a photographic sense, slow. This is an inference not warranted by the premise, as there is no reason to believe that the top film in any way loses speed by being imposed upon a film ef emulsion instead of a glass plate. Without hazarding any conjecture as to the why and the where- fore, I think that, in a pictorial sense, there wiU be found a greater range of gradation and more roundness, and, if I may coin a word, more stereoscopicity, of effect, with an increased (or abnormal) exposure than obtains in a homogeneous film with any exposure. It must also be borne in mind that, with the ordinary dry plate, the effect of more exposure than will influence the region of correct representa- tion makes for flatness of image and loss of true gradation. With the multiple film, however, it tends towards increased roundness of image. With an exposure calculated to reproduce the shadow details to their fullest •extent, and which I describe as abnormal because it is more than can be usefully given to a homogeneous film, are the best results obtained with the new tool. I am disposed to suggest that this is only a natural result of the ability of the multiple film to successfully render a longer range of contrast. In other words, the sensitive film which will reproduce in natural ratio the widest range of light and shade may be expected to produce at the same time the best pictorial effect. It is for this reason that I am entirely opposed to the idea of over- exposure and stripping the top film, a method which I regard as an indica- tion of failure to properly understand the principle of the compound film. We are, by this method, only able to make a picture upon one of the lower films. Now, for this purpose, it is best to use such a one in its simple form,, and not to risk failure by exposing through some other film, which has to be wasted. Wilful waste makes woeful want, as the old alliteration has it. In point of fact, the useful detail of the negative will be found upon the top film, and this detail we cannot afford to lose in our negatives. Halation. The question of the freedom of the compound film from halation or light reflected from the posterior surface of the supporting glass plate, depends upon two points— first, that the difference in sensitiveness between the top and bottom films shall be at least as great as the differ- ■ence in the value of the light reflected from the brightest and the least bright portions of the object to be photographed; and, secondly, upon the | method of development employed. There can be little doubt as to the efficiency of the principle employed, viz., that the light shall be inter- cepted and 'usefully (in the photographic sense) employed by the loner film. When " backing " is resorted to to prevent reflections, it is hut a makeshift method of obviating the disagreeable effects of light in the wrong place. The principle of the multiple film is to prevent the light passing into the glass or support. In actual work a triple film gives practical freedom from this defect in most trying circumstancea, and that without backing. This is not the place to discuss whether a commercial article is effective or not; but I am compelled to add, that if the difference in sensitive- ness between the top and bottom films in the commercial article be not now sufficiently wide to secure without halation the most violent contrasts which may present themselves for representation, the principle still ap^ plies, and it is but necessary to lower the photographic sensitiveness of the bottom layer to perfectly effect th; object. Or, as an alternative for extreme ranges of contrast, a fourth film might be added. So mnch depends, however, upon the method of development, that I believe tbreei films to be ample for all practical purposes. Exposure, I now pass to the question of development and practical treatment of the films. There are two exposures for multiple films. First, the normal, is the correct exposure for the top film,'snpposing it to be coated upon a glass plate by itself in the ordinary way. For such an exposure development will be normal, and precisely the same as it would be supposmg the sensitive film to be of_ a homogeneous rapid character. That I need not discuss further. The second exposure is one which I prefer to call ahwrmal rather than, over-exposure. It will be apparent that, with underlying films of less rapidity, and each underlying film protected by a light-absorbing filter of emulsion above it, without recourse to any devioeiin develop- ment for restraining or retarding the effects of the light action, the lowest films are capable of absorbing and using a largely extended exposure. I am informed that the relative rapidities of the three emulsions in the triple films are as 1, 4, and 30, and, when to tliis'margin of speed which exists between the top and bottom film is added the" resistance tojlight passage of the first and second films themselves, it will be obvious that there is a considerable available margin of latitude in'exposure. The point, there- fore, when over-exposure in the usual sense of the word begins, is so far away from the normal as to render it unnecessary to take it into immediate consideration. Development. With an abnormal exposure, development must be " tentative." There* are two methods : — First, by working with solutions of suitable>nergy to develop the image until sufficient detail be obtained, and then, by the liberal use of a soluble citrate, to develop up density and contrast from the lower films, in which there is a store of density-giving emulsion to which the ordinary worker is quite unaccustomed; or, secondly, to begin with a very dilute and restrained (with bromide) solution, so as to secrue^in the lower film suffi- cient density first ; afterwards, if necessary, acting upon the top film with a more energetic developer, to bring out such detail as may be desired. I am not quite certain as to which of these methods I prefer, but I am largely influenced by the fact that it is the second method which the in- ventor of the plates relies upon to make his pictures. I have had the pleasure, on more than one occasion, of seeing him develop 15 x 12 interiors by this method with such ease, and so much regular success, as to make me doubtful of the propriety even of mentioning the first method. I cannot do better, therefore, than give his method, premising that the same principle appUes whatever developing agent be employed. The developer Mr. Sandell prefers is a mixture of hydroquinone, eikonogen, and rodinal, as follows : — Concentrated Solution. Hydroquinone 30 grams. Eikonogen lOo „ Bodiual 9 drachms. Sulphite of soda 2J ounces. Carbonate of potassium,,,,, 2J „ Water to make 20 ,, Supposing we have to develop a plate which has received, say, three times a noinuJ exposure, generally the best results can be obtained 444 THE BRITISH JOURNAL OF PHOTOGRAPHY. [July 14, 1893 with from three to six times a nominal exposure. Commence develop- ment with a weak solution, thus : — Dilute Tentative Developer. Stock solution 1 part. Water ._ 15 parts. Bromide of potassium (10 per cent, solution) About twograim of the latter to the ounce of solution. This will probably begin to produce an image in from two to four minutes. The highest lights should appear first (although they are in the lower films), and density and detail should grow steadily. The important point to keep in mind is that the high light should be developed by the first solution, rather than the detail. If detail comes beely, the developer may be considered too energetic, and the remedy obvious. II detail comes but little, it is of no importance, for being within the topmost film it can be readily acted upon and drawn out by a more energetic solution, and that without there being time enough for the stronger solution to affect the density-giving sub-film. Should detail grow faster than density, then, as we can only attack the density-giving sections of the plate through the top film, we are forced to resort to the first method of development, viz., the use of restraining citrates and bro- mides to enable the solution to get down into the lower films without overdoing the top layer. But by this procedure we risk making a thicker negative than by cautious development by the second method. In developing abnormal exposures in multiple films, if there be any error, let it be on the side of a too dilute developer to commence with. The manifest simplicity of Mr. Sandell's method should, I think, com- mend it, and I suggest it as the easiest one and the most reliable. In case, of need, however, density can be obtained by the first method with certainty, but it may become a little difiicult to watch the action of development. By the second method, the progress of development can be easily followed, and it is not only not necessary for the image to be lost sight of, but it indicates the use of a too strong and energetic solution, or an insufliciently restrained one. The notion that with a multiple film development must be a closed book I ask you to remove from your mind. There is no such necessity, and, should the image be lost tojsight, it is the clearest indication of injudicious procedure. I never expect to see any indication upon the back of a triple film of the image, and when I lose sight of the progress of development I know that it is because I have been impatient or unfortunate in my judgment. In such a case, however, with the reserve force of the multiple film a negative will be the result, where with a simple emulsion extreme flatness would be expected. I have not mentioned pyrogallic acid development, nor do I propose to advocate any particular developing re-agent. Whichever be the reducing agent with which you are best acquainted, will be for you the right one to use. It is not the developer (the reducer), but the developer (the individual), which makes the negative. For pyro development, however, I think there is nothing better than the following : — A. Neutral sulphite soda 55 ounces. Boiling water to make 10 ,, B. Pyrogallol 1 ounce. Nitric acid 20 minims. Water to make 10 ounces. C. Bromide potassium 1 ounce. Water to make _ 10 ounces. D. Carbonate soda (anhydrous) 1 ounce. Water to make 10 ounces. E. Citrate soda 1 ounce. Water to make 10 ounces. B, C, D, and E are not exact ten per cent, solution. I prefer the sulphite in a separate solution, and concentrated. Normal Developer, Pyro solution 20 minims. Bromide solution 10 ,, Sulphite solution 60 ,, Carbonate solution 40 to 80 „ Water to make , 1 ounce. Tentative Developer. Pyro solution 5 minims. Bromide solution 5 „ Sulphite solution 60 „ Carbonate solution 10 „ Water to make 1 ounce In place of this latter, the normal developer may be diluted from one quarter to one-tenth strength, although I prefer to have a larger pro- portion of bromide than is in the normal, and an equal strength of sulphite. The latter because, whilst doing no harm by its presence, it enables one to add stock pyro and carbonate to form a more energetic solution, without discolouring the film. Fixation. There is only one other point to which I need call attention, and that is, that the fixing bath should be new and strong— eight ounces of hypo' to a pint of water, and fixing should not be performed on white light. An acid fixing bath works well with multiple films, both hardening the gelatine and brightening the negative at the same time. The best form is : — Hypo 8 ounces. Acid bisulphite soda 2 „ Water 1 pint. With such a fixing bath, complete elimination of the soluble silver salts is quickly performed unless the solution is unduly cold. In this case the remedy is obvious. Warm the fixer to 55° to 60° Fahr. SOME POINTS IN CONNEXION WITH DEVELOPMENT. By C. H. BoTHAMLEY, F.I.C., F.C.S. At a meeting at which so many papers on the all-important subject of development are to be read, it is difficult to deal with the matter without in some way encroaching upon the ground covered by the other writers. Apart from the introduction of new developers, few photographic ques- tions of late have attracted more attention or excited more discussion than the relation of the gradations of a negative to the time of exposure on the one hand and the mode of development on the other. At present it cannot be said that any final decision has been arrived at as between the theory that the gradations depend only on the intensity of the light and the time of exposiure, and the theory that the gradations may be- modified by the mode of development. One of my scientific friends rarely troubles himself about any energetic scientific controversy whilst it is still going on. He generally says that he will go into the question " when the dust has settled a little." He is a busy man, and his attitude in this respect is quite intelligible. It iS' clear, however, that if every one were of the same mind the dust never would settle, for the dust of a scientific controversy, heavy though it may be, does not as a rule subside by its own gravitation. The views that I have the honour of submitting to this Convention you will, perhaps, with your usual indulgence, be good enough to regard as a small attempt to- act the part of Aquarius, and to help a little towards the settling of the dust of the controversy that is now being waged over the relation between exposure, mode of development, and the gradations of negatives. I. cannot, I regret to say, lay before you any new facts ; but I will venture to ask you to look at some of the old facts in a way which, if not new,, has, at any rate, not received the attention that it seems to merit. The controversy, in its present aspects, has been excited by the re- markable papers of Messrs. Hurter & Driffield, and the no less able papers of Captain Abney. Now, in the first place, it has not been sufficiently recognised that- Abney, and Hurter & Driffield are quite agreed on the main point, that the amounts of silver reduced at different parts of a negative are deter- mined by the amount of light action, and not by the mode of development. The question between them is really limited to the precise form of the equation that connects the two quantities, Hurter & Driffield holding that the deposit of silver may be regarded as homogeneous, whilst Abney holds that it must be regarded as heterogeneous, and consisting of solid, particles distributed in accordance with the " law of error." Many photographers, however, on the basis of their accumulated ex- perience, contend that they have the power, by altering the mode of development, to alter the gradations of their negatives, Ac. It will not be very difficult to show that both of the parties may be right. To a great extent the confusion and misunderstanding arises from the use July 14,1893] THE BRITISH JOURNAL OF PHOTOGRAPHY. 44S of tlie same words in different senses ; it is the old story of a difTerenoe in lan^aage and not in facts. Not a little of the difficulty arises in the first place from the fact that Hurter tt UrilVield use the word density in a sense that is quite accurate and justifiable from a scientific point of view, but which unfortunately is not the sense in whicti the word is commonly used by the photographer. By •' density " Hurter * Driffield mean the absolute quantity or mass of silver in the film at a given point ; the photographer means the opacity of the film at that point. The two are intimately connected, but they are by no means identical, and one cannot but regret that photographers should have adopted the word density when the correct word, opacity, was already coined. It is an important example of the folly— I ask no pardon for using so strong a word — the folly of which the practisers of any art whatever are guilty, when they use in a loose and inaccurate sense words which already have a definite and recognised meaning in any of the sciences on which the art in question may happen to be based. Hurter & Driffield's fundamental result is that the ratio of the densities corresponding to different amounts of light action cannot be altered by changes in the mode of development. So far as any quantitative evidence goes, that statement must at present be accepted as correct. Photo- graphers say that they can alter the gradations of their negatives. There is really no necessar;/ antagonism between the two statements. At the outset you will probably admit that the way in which photo- graphers, as a rule, estimate the gradations of their negatives is, at the best, somewhat rough-and-ready, and cannot claim any special degree of JKSCuracy. What a photographer has in his mind when he talks about gradations is, in ninety-nine cases out of a hundred, printing qualities. Of course, this is the all-important point in actual practice, seeing that the negative is but a means to an end. Now, the printing qualities depend on the ratio of the opocitie) of the different parts of the negative, and it is quite possible for the ratios of the densities to remain constant, as Hurter & Driffield say they do, whilst the ratios of the opacities vary widely. It is not necessary to enter into a detailed explanation of the law that governs the relation between the quantity of an opaque substance, such as the silver in a negative, and the quantity of light that it absorbs ; the law is a simple one. May I ask your attention to the following table : — First Case. Second Case. Thkkneis Ratioa Qmntity Ratios 'iliii-.kness Badoi Quantitii Eatitw of the o/tht of Light 0/ ih.' of the of the of Light of the Silver Venii. Trans- Liaht Silver Densi- TrnM- LigM Layer. ties. mitted. Transmitted. iMyer. tiee. mitted. Transmitted. 11*4 2 1 i 64 2 2 i 3 4 2 ,V 16 3 3 J 2 6 3 „', 4 4 4 ,\ 1 8 4 ,J„ 1 It appears that in the two cases the ratios ot the densities are the same, but the ratios of the opacities, or, in other words, the printing qualities, differ widely, because the absolute values of the densities are different. The two cases represent the same negative, development in the second case being carried on longer, so that the quantity of silver deposited at any part of the negative is, in the second case, just twice as great as in the first. What it seems to come to, then, is this, that according to Hurter & Driffield we cannot in development alter the ratios of 1 the densities, but, by stopping the processes at different stages, we do alter the absolute values of the densities, and thus very considerably alter the ratios of the opacities, that is to say, the printing quality. It may be asked, however, how this explains the apparent effect of the usual modifications in the composition of the developer. The reply in the first place is, of course, that some of these modifications simply have the effect of making development slower, and thus making it easier to stop the process at any desired point. It is, however, for a full discussion of the problem, essential to take into consideration a point that is often neglected : Is any one prepared to contend that sufficient attention has hitherto been paid to the Influence of general fog — a uniform deposit of silver all over the negative — in modifying the " gradations " and altering the printing qualities of a negative ? We frequently meet with or hear the statement, " beautifully clear in the shadows ; " but how often is this an accurate statement of fact — how often does it represent inaccurate observation ? It is very easy to be deceived by contrast, but, if the plate is put in contract with white paper, it will in the great majority of cases be found that there is really an appreciable deposit where there seemed to be no silver at all upon the negative when it was examined by transmitted light. The term "general fog " is here used in the ordinary sense to denote a uniform deposit all over the negative, produced by the action ot the developer independently ot any action of light. Then comes the question. What is the effect ot general fog on the ratios of the opacities, or, to use the common phrase, the "gradations?" Since to add a constant quantity to the terms ot a ratio diminishes the ratio, it is clear tliat the fog will lessen the ratios ot the opacities, and thus tend to make the negative flatter or softer. The greater the amount of fog, the smaller and smaller will the ratios become, or, in other words, the flatter or softer will the negatives be. In all Hurter & Driffield's experiments the inflnence ot tog was elimi- nated by subtracting the value of the fog from all the measurements before calculating the ratios. It is noteworthy that in almost all cases the fog value was altogether too distinct to be negligible. In actiukl prac- tice, however, whatever fog there may be is not eliminated or removed, but exerts its influence all through the various uses to which the negative is put. As a matter of fact, very few of the developers commonly used can be allowed to act upon ordinary plates for four or five minutes without pro- ducing an appreciable amount ot general tog. The amoant of tog is increased by — (1.) Increasing the proportion of alkali. (2.) Increasing the concentration of the developer. (3.) Eeducing the proportion ot bromide. (4. ) Prolonging the time of development. Whilst, on the other hand, the amount ot fog is reda:ed by — (1.) Beducing the proportion of alkali. (2.) Increasing the proportion of bromide. (3.) Shortening the time ot development. The proportion ot pyro does not seem to exert any marked influenoe in this respect. Diluting the developer acts in two ways ; the dilution of itself tends to reduce the amount of fog, but the prolongation ot develop- ment, necessitated by dilution, tends towards the production of fog. When the photographer endeavours to compensate for over-exposure, he reduces the amount of alkali, and increases the amount of bromide ; but, as we have just seen, these are modifications which tend to prevent the production of general fog, and consequently increase the contrasts ot the negative. When, on the other hand, the negative is under-exposed, the proportion of alkali is increased, the proportion of bromide is- reduced, and sometimes the developer is diluted ; but all these modifica- tions tend towards the production of fog and a consequent reduction of the contrasts of the negative. It is scarcely necessary to point out that so long as fog remains slight there is a tendency to continue development, {ind thus, as pointed out at the beginning, to increase the ratios ot the opacities, that is, to increase the contrasts by increasing the absolute values of the densities. When, however, fog makes its appearance, there is a tendency to stop development at a stage when the absolute values ot the densities are comparatively low, the ratios of the opacities are low, and the negative is " soft " in its gradations. To sum up, it would seem that, so far as present experimental evidence goes, the photographer cannot by modifications in development alter the ratios of the densities of the silver deposit at different points ; these are determined by the amount of light action. He can, however, and does, alter the ratios of the opacities, or, in other words, the printing qualities; (1) by stopping development at a particular stage, (2) by making such modifications in the mode of development as tend either to reduce th» general fog and thus increase the contrasts, or to increase the amoant of fog and thus lessen the contrasts. The two kinds of modifications are- designed respectively to meet over-exposure and under-exposure. A discussion followed. i^-etos anti i^otcs. Manchestkr PHOTOGBArHic SOCIETY. — July 15, Rowsley (ramble). Northern PHOTOaBAPmc and Sciextific Association. — July 15, Batterse* Park. Hackney Photoobaphic Society.— July IS,' Meld- Hauff. Photographic Club. — July 19, The Permanency of Gelatine Prints. 26, CoUodio-chhride Printing. Chanqe of Address. — Mr. Redmond Barrett has changed his address to 129, The Grove, Hammersmith, W. Gosport Photookaphic Society. — July 15, Chichester, leaves Portsmouth Harbour at fifty minutes past one, p.m. BiRMlN-GHAM PHOTOOBAPHIC SOCIETY.— July 15, Last day for sending i» photographs for the Meriden Excursion Comi>etition. 18, Social evening. 44C THE BRITISH JOURNAL OF PHOTOGRAPHY. [July 14, 1893 Rrbatcm — Tn Mr. HuRh Blackwood's letter last week, "F. Darlot & Co.' aliouW reaa"" F Darton I Co.," the firm's address being 142, St. John-street, ClerkenweU, E.C. -THE PHOTOGRAPHIC TlME3."-We understand that Mr. W. E. Woodbury is now Editor of the Photographic Tinies (New York). That journal is to be -increased in size, and prize competitions are to be instituted. The Japan Photographic Exhibition.— It was arranged that Her Imperial Maiestythe Empress was to visit on June 23 the Exhibition being held m Tokyo, by the Photograpliic Society of Japan. To the Exhibition a separate exhibit of Japanese photographs has been added. New Premises for the PHOToaBAPHio Society ok Great Britain.— We understand that the Photographic Society of Great Britain will shortly remove from their present premises at 50, Great Rassell-street, to more convenient and less loftily situated rooms at the house of the Institute of Chemistry in Bloomsbury-stpiare. "Fair Holidats."— We understand that, by an arrangement among the principal photographers in Greenock, most of the studios in that town were closed for one week, from Mondav last, July 10, thus enabling both emplot/es and assistants to have a week's holiday. Some such arrangement may commend itself to professional photographers in other large towns. Metol-Andresen.— The following new formula is recommended for the use of metol-Andresen :— Dissolve in 8 ounces of water, Andresen's metol. 10 grains; then add, carbonate of potash, 60 grains ; sulphite of soda, 30 grains; bromide of potassium, 2 grains. For over-exposure add a few drops of a ten per cent, solution of acetic acid. For under-exposure add a few drops of a ten per cent, solution of carbonate of potash. Photographic Exhibition .\t Hove. — In connexion with the sixteenth annual Exhibition of the Hove Industrial and Horticultural Society, to be held at the Town Hall, Hove, on September 20 and 21, 1893, there will be a photographic section under the auspices of the Hove Camera Club. Particulars .and entry forms can be obtained of the Hon, Secretary of the Industrial Society, H. Emery, 142, Church-road, Hove, Brighton. An Ootino. — Messrs. Adams & Co., of Charing Cross-road and Aldersgate •street, inform us that the whole of their factories as well as their retail establishments will be closed on Saturday next, July 15, the occasion being the outing of the staff numbering forty-eight persons. Messrs. Adams say : '.' In order to cope with a very heavy season the majority have been working from eight a.m. till nine p.m. since Christmas last, and deserve a little relaxa- tion." We trust an enjoyable day will be spent. SoniH London Photographic Society's Exhibition. — The South London Photographic Society will hold their fifth annual exhibition at the Peokliam Public Hall, llye-laue, Peckham, S.E., on November 7, 8, 9, 10, and 11 next. In addition to the members' classes there will be open classes for the following ; Medalled pictures ; medalled lantern slides ; pictures that have not received any award ; lantern slides that have not received any award. It is under- stood that the number of pictures and slides which any exhibitor may send in will be limited. Ashton-under-Lyne Photographic Society.— July 15, to Chew Brook' Leader, Mr. C. E. Redfern. Waggonettes will leave the Society's Rooms, Henry- square, at 1.30 pr'ompt. Tickets, Is. 6d. each, to be had at the rooms, or from the Secretary, up to Weilnesday evening, July 12. Mr. Carrodus, from the Technical School, has promised to accompany the party and give the members any assistance he can in the choice of pictures, &c. 29, Ramble to Liverpool, &c. Leader, Charles Lord, Esq. Further particulars later. Robert T. Marsland, Hon. Secretary, 74, Blandford-street, Ashton-under-Lyne. How TO avoid Blisters. — Mr. Williams R. Kenuan, of Dame-street, Dublin, •writes ; " The following I find the best way to avoid blisters in albumenised paper. After toning in the usual way, mix some liquor ammoniae with hypo bath and fix prints as customary ; but when fixed leave the prints in the hypo ■bath with some of the hypo, and dilute very gradually with water, keeping •the prints moving. The secret is in not making a sudden change from the hypo to the plain wa.shing water, givingplenty of time to eliminate the hypo. When this is done, blisters are a thing of the past. I send you this, as it may prove useful to some of my brother professionals who like myself believe still in albumenised paper, - Photographing at Raglan Casti.k.— " View Finder " writes : " Last week I went to Raglan, in Alonmouthshire, for the purpose of photographing ■the fine old ruined castle. On arriving at the castle enclosure, I found that, in addition to an entrance fee of sixpence, half-a-crown extra for the privilege of photographing was demanded of me. I told the person in charge that it was an exorbitant amount to pay ; but he denied this, stating that, having ^photographs himself for disposal, he had lost the sale of them (so he said) through so many amateurs coming to the place, and remarked, 'people, instead of buying my photographs, now take them for themselves.' This seemed so absurd that I pointed out to him that, on an average, not one person in a hundred was a photographer, taking the population of the country ; but all argument was useless, as he only referred me to a notice board, ou which was painted : ' Amateur photographers wishing to take photographs of the Castle can do so upon payment of2s. 6d. ; professional photographers, 21s.' Although I had undergone a hot and tedious journey — the light was perfect — and I nad come specially to photograph, I determined not to do so, and I hope my example will be followed by others." *»* IVUh the iovmiM, of Fridayiiext, July 21, will lie presented a group of inembera of the Photographic Convention of the United Kingdom, taken at Plymouth on July b last. Tlie picture is revroduced in coHotype by Messrs. Morgan ox of the character such as herein- before desoribed, iu which a pack or series of plates or sensitised sheets are successively passed round from front to back or bark to front, substantially in the nianiicr and for the purjioses hercinbeforo deseribeil, and illustrated by way of example iu the drawings hereunto annexed. Mutino^ of JboctetteiS. MEETINGS OF SOCIETIES FOR NEXT WEEK. DatooIUMting. NHme of 3oci«t7. Place of Meeting. July 17 Asao. Stndio, Nethemte, Dundee. „ 17 UaftiDRs and St. Leoua'rds „ 17 17 Oreyhound Hotel. Hanover Hall, Hanover.nark, S.K. Club Eoom, Colonnade HoteL „ 17 18 Birmiusham Photo. Society ... , 18 „ 18 206, Mare-Btrect, Hackney. Canonbury Tower, Islington, N. 18 „ 18 Paisley 18 „ 19 Club Rooms, 13, Apvr-strect, Bnry. The Assembly Rooms, Hiirh-road. Anderton'3Hotel,Fleot-stre8t,K.O. The Studio, 15, C.ambi-idge-aroade, 3, King's-road, Southsea. Clnb Eoom, Colonnade Hotel. 71, Prospect-street, Hull. Champion Hotel, 15, Aldersgate-st. The Lyceum. Uuion-st., Oldham. Society's Rooms, 136, High-street, Public Hall, George-street, Croydon „ 19 „ 19 „ 19 19 „ 20 Birmingham Photo. Society ... „ 20 „ 20 „ 20 „ 20 Hull London and Provincial „ 20 „ 21 Oslonl Photo. Society „ 21 „ 21 „ 21 Trinity Church Room, Morton-st. „ 21 „ 22 Hnll 71 Prospect-street, Hnll. North London Photographic Society. — July 4, Technical Meeting, Mr. J. R. Williams in the cliair. — Consequent on the demonstration given at the last meeting, a discu.ssion took place on amidol and nietol as developers. Mr. A. E. Smith showed prints from duplicate negatives, one develoj)ed with amidol by Mr. Morgan in the course of his demonstration, and the otlier developed with pyro by Mr. Smith. The prints from the latter were far superior. Mr. Spiller obtained better results with amidol than pyro in developing instan taneous exposures, especially when the light had not been very strong. Mr. Brewer showed some excellent cloud negtitives developed with amidol. When required, he had no ditficidty in obtaining density, using plenty of bromide. The negatives were on isoohromatic plates, one or two yellow screens being used as occasion required. He had had a special lens flange made, with a slot in it to take the screen, a band passing over the slot to keep out light. Mr. Groundwater had used metol for negative work, and, diluting the normal formula with an equal amount of water, obtained satisfactory results. There was a good show of hand cameras, mostly of well-known brands, but Mr. A. E. Smith showed one of liis own nuvke with a verj' ingeniously contrived shutter. Two wooden drop pieces, actuated by springs, work in a rebate ; they are released by a lever attachment in succession, and more or less quickly according to the length of a toothed catch adjusted to the lever. Mr. Douglas had one made by Turnbull, of Edinburgh, which had focussing screen, and would rack out far enough to allow the use of one combination only of the rapid symmetrical lens with which it was fitted. It was considered a matter of great regret that the word "detective " should ever have been applied to the hand camera. It had given the dog a bad name, and the public now looked upon any one carrying a hand camera with suspicion, which, moreover, recent advertisements iu the photographic press had tended to accentuate. North Middlesex Photographic Society.— July 10.— The subject of Cresco- Fijbim Knlariiing w.is dealt with by the Secretary. He fully explainep the negatives, which were most suitable for treatment by this process, and how to go about the actual work of enlarging, and showed numerous examples of successful work, both negatives and positives, opals, transpjirencies, sc. A discussion followed, which was sustained by most of the members present. The result of the outing to Scwardstone was that Mr. A. J. Golding was first, the I'rcsident (Mr. J. W. Marchant) second. Hackney Photographic Society.- July 4, Mr. Puttock in the chair.— Messi's. Uita, Low, Kort, and Dr. Harris were duly elected members. Tlie popularity of the Society was truly demonstrated, as application for member- ship was made from Burmah. Messrs. T. H. Smith, Dear, Gosling, Hudson, Koofe, showed work. The Hon. Secretary then showed Spratt Brothers' new camera stand. It was easily set up, the principal advant;ige being that in place of screws at the first joint it automatically locked and fixed itself. Mr. Gosling showed a view finder which he had fixed in a small black box. The image could be seen iu any light clearly. Mr. Rooke asked. Could halation be reduced in any way ': Mr. Beckbtt thought methylated spirit nibbed on the negative with wash-leather would do it tolerably. Mr. Cross showed a negative which he had intensified, but which was much stained. The general opinion w.as that it was not thoroughly fixed. Mr. NuNir asked if halation was not sometimes caused by stopping down. Mr. Beckett suggested that halation was not showu so much with a large stop because "camera fog" was more evenly difi'used. From the question-box: "How to obtain brown tones on lantern plates 1 " Various replies were given, such as using printing-out lantern plates. Alphas, using carbonate of ammonia. A good reducer wa% asked for,, and that given by Howard Farmer was recommended. Mr. Iloofe asked what to do to avoid metallic de]>osit on plates '! Tlie Ho!«. Skcrktaky uitl methylated spirits woulil reduce it and advocated for old plates fall exposoiv and less alkali than usual. South London Photographic Society.— .July 3, the President, Mr. F. W. Edwards, in the chair.— Mr. W. J. BEf.TON gave a demonstration of the manipulation of the Paget print-out lantern plates and opals. He eipkioed the various stages in a very lucid and able manner. For printing the opaU in ordinary printing frames he showed a simple cardboard mask and frame which the Paget Company were |>lacing iu the market for sale for a few pence. He also showed a frame specially constructed for printing the opals, and gave the formulie of the toning and fixing bath (both combined and separate) which he used. At the conclusion of the demonstration the results were passed round, and the lantern slides shown iu the Society's lantern. During the course of the evening tlie President, on behalf of the Koyal Humane Society, presented Mr. Charles Farrant, one of the members, witti a testimonial for saving life. It appeared that on May 25 last Mr. Farrant, in company with another memljer, were photographing along the banks of the Thames at Greenwich, and noticed some children playing on one of the landing-stages. Thinking they would with but little aiTangenient make a good picture, Mr. Farrant and his friend pro- ceeded to get his camera ready, when all of a sudden a cry for help was raised, and it was seen that a lad was fast being carried out into mid-stream. Without stopping to divest himself of any of his apparel, Mr. Farrant swam to the rescue, and succeeded in bringing the boy safe to land. Attendance, forty- eight. Brixton and Clapham Camera Club,— Tuesday, July 4 (Dr. J. Reynolds, F. R. G. S. , in the chair). — It was decided to afford members systematic assistance in the more elementary principles of photography. With this object in view the Club elected a Committee of Instruction, consisting of six members, each- member of which will give the first half-hour of each general meeting for the purpcse of answering any questions on elementary photography that may be submitted to him. A Committee was also formed for the criticism of negatives and prints produced by the less experienced members. Anyone will now have an opportunity of submitting his work to the Committee, who will report as- to the composition, development, and exposure of the negatives, also on the- development, printing, toning, and mounting of the prints. In the event of lanteni slides being submitted for criticism, it will be nscessary in every case for the niember to furnish a description of the scene, the nature of the process- by which the slide was produced, i.e., collodion, gelatine, &c., exposure, development, and mode of toniug ; also to submit the negative from which the slide was produced. As soon as the usual business of the Club had been transacted the President gave a short but interesting description of some of the- extinct monsters that inhabited the earth iu the pre-historic period. The description was illustrated by some beautiful lantern slides which were very kindly lent for the occasion by the Rev. H. N. Hutchinson, B.A., F.G.S., some- of whose PaliBontological and geological researches are embodied in his works on Extinct Monsters, The Autobiography of t)ie Earth, kc. Birmingham Photographic Society.— July 4, Mr. J. H. Pickard in the chair. — A number of negatives taken on the recent whole-day excursion of the Society to Dovedale were staged on racks on the table. These negatives were inspected with great interest, not only by those gentlemen present, who had' gone the excursion, but also by the general body of members, and the display aflorded convenient means of comparison of results and notes as to the obtaining of those results. A full and useful discussion was evoked by this means, about fifty negatives and prints being shown. Bournemouth Scientific and Antiquarian Society.- July^, Excursion to Beaulieu Abbey. — Theparty, consisting of about thirty of the members and their friends, including the President and one of the Vice-Presidents of the section, also several ladies, took train to Brockenhurst, and, after a delightful drive by way of Lady Cross Lodge, and Hatchet Gate, reached the picturesque village - of Beaulieu. The old Abbey (founded in 1'204 by King John), the village aiid. the scenery by the river proved of great interest to the photographers, the weather being most suitable for securmg excellent pictures. Photographic Society of Japan.— A regular Monthly Meeting of the above- mentioned Society was held at the Rooms of the Geographical Society of Japan, Nishikonyacho, Kiobashi, Tokyo, on Friday, June 2, Mr. Edmund R. Holmes in the chair. — Messrs. Bnulfish and Pierce had sent in some ready- sensitised paper of two difi'erent kinds. One had a polished surface, aud- appeareil to be a gelatino-chloride paper, the other had a matt surface. Mr. K. Arito was able to state that the paper was in no way discoloured, so that there was evidence of its good keeping qualities, and that it printed brightly and clearly. He had not, however, had time yet to tone any proofs. Mr. I.. Tanaka was instructed to experiment with the paper, and to report his resulte to the next meeting. Work done by the anastigmatic lens of Carl Zeiss, of Jena, was shown. The examples showed a most remarkable uniformity of definition from the centre to the extreme comers of the prints. Mr. W. K. Burton explained that these lenses were of large angular aperture, of tlat field, and, at the same time, without astigmatism. There were various lenses that combined any two of these qualities ; but, so far as he knew, this was the first that combined the three. The form of the Zeiss anastigmatics, even of large angular aperture, was such— being mounted in a short tube— that they could be used as wide-angle lenses if stopped down. He would, however, be in, a position to report more fully to the Society on these lenses in a month or two. There was a discussion as to the manner of dispo.-sal of the iloaation maile to the Society by H.I.M. the Empress on the event of her visit to the Exhibition, there beingageneralfeelingthat this money should not go into the ordinary funds of the Society, but should be used to provide some permanent memorial of the visit. It was eventually decided that the money should be used to pay for the striking of a small silver medal to conmiemorate the event, and to be presented to each member of the Society. After the regular meeting there was an extra- onlinary meeting to consider the matter of the Secretaryship. It was pro- posed, seconded, and carried that Mr. W. K. Burton be elected " Corresponding-, 448 THE BKiTlSH JOURNAL OF PHOTOGRAPHY. [July 14, 1893 Secretary " in addition to Mr. I. Ishikawa and Dr. Augustus Wood, ordinary Secretaries. May 20.— Annual Meeting. Professor D. Kikuchi, M.A., in the chair.— Mr. \V. K. Burton was elected Viee-Chairman, and Dr. Augustus Wood, Foreign Secretary. Prince A. Tokugawa, Dr. Professor J. Scriba, Professor John Milne, F.R.S., Mr. 0. Keil, and Marquis T. Konoye were elected Vice- Presidents. ♦ FORTHCOMING EXHIBITIONS. 1893 August *. Welsh National Eisteddfod. The General Secretary, Pontypridd. Sept. 25-Nov. 15 ... Photographic Society of Great Britain, 5a, Pall Mall East, S.W. Assistant Secretary, B. Child-Bay ley, 50, Great Russell-street, W.C. October 1-31 Hamburg. Das Ausstellungs Committe des Amateur Photographen Verein, Schwanenwik, 33, Hamburg. „ 9-Nov. ... Photographic Salon, Dudley Gallery, Piccadilly, W. Hon. Secretary of Organizing Committee, A. Maskell, 215, Shaftesbury-avenue, W.C. December Madras. The Hon. Secretary Amateur Photographic Society, Madras. « iEK!)angc atolumn. ExchaKge cabinet ^portrait leas hj Laverne, cost 67. 68., for hand camera, or pair of stereoscopic lenses.— Address, W. H. Gbddes & Son, Applegate, Arbroath. Wanted a 15x12 camera slide and lens, if out of repair would do; will excbanfre Harrison's head ami body rest, Fallowfield oold rolling press, and Dallmeyer's aluminium No. 3 portrait lena. — Address, J. Mullens, Geneva-road, Winsford. Ens(tDet0 to (jrorresponHentg. *,* All matters intended for tht text portion of this Journal, including mieriea and Exchanges, must be addressed to " Thk Editor, Thb British Journal op Photography," 2, York-street, Covent Garden, London. In- attention to this ensures delay. *,* Correspondents are informed that we cannot undertake to ansioer com- munications through the post. ",* Communications relating to Advertisements and general bicsiness affairs should be addressed to Messrs. Hbnby Greenwood & Co., 2 York-street, Covent Garden, London. *,* It would be convenient if friends desiring advice respecting apparatus, ^aitures in practice, or other information, would call at the Editorial Office either on Wednesdays from 4 to 6, or Thursdays from 9 to 12 noon, when some one of the Editorial staff will be present. E. J. Cab. —The book has not yet been published. W. T. M. Davidson. — Wilkinson's book, or Burton's Printing Processes Marion &, Co. E. R. C. — The term is quite misleading. The prints 'are simply collotypes printed in colours after the manner of chromo-lithography, separate plates being used for the various colours. T. Biggs.— If upon testing the gelatine with litmus paper it strikes a red colour at once, it should not be used for mounting silver Sprints in optical contact ■with glass, as, sooner or later, it will have a deleterious action on the picture. G. Edwards.— Tlie fault is what you were told, the pictures are much out of focus. As the camera is a " fixed focus " one it is clear that the lens is not at the right distance from the plates. The one who supplied the instrument will see that the fault is remedied. A. J. — We have found no such tendency. If the prints are properly manipu- lated they should not change colour in the way mentioned. As no details of the method of working or the toning baths employed are given, we are unable to say what is the cause of the trouble. Novice. — We do not make a practice of recommending any particular maker's goods. Consult the advertisement pages of the " Lantern Record," or pro- cure the catalogues there advertised. By indicating your requirements to any one of those firm.s, you will easily get what you desire. D. Lloyd. — 1. Use a small stop, and give a full exposure— say, six seconds, with/-32. 2. Possibly forced development of ammonia-prepared plates, but it is difficult to say with certainty. 3. About 18°, we believe. 4. It would be lusloss to attempt to obviate " movement " of the head by the aid of retouching. C. Hearley asks how long black varnish ought to take to dry on a negative, as he has some, obtained from a first-class oilman, that does not dry in less than three days. — A photographic black varnish dries in, comparatively,! a few minutes. Procure a bottle of Bates' black. It may be had at any photo- graphic wareliouse. T. H. VVHarton complains that the surface of opal glass is verv different from what it was some years ago, and is not nearly so nice to work upon with colour. He asks the reason.— Most of the opal glass at the present time is grained by the sand-blast method, formerly it used to be hand ground. It is that which makes the difference in the surface. C. Granville Wood. — Precisely in tlie same way as prints on albumen paper are washed. The size makes no more difference in one case than in the other. S. Blake. — To make a thin solution of indiarubber, take masticated rubber which may be obtained at such houses as Hancock's or Macintosh's, and dissolve it in benzole. Perhaps the simplest way is to buy a small tin of solution and thin it down, to tlie consistence desired, with benzole. This is less trouble than dissolving the rubber itself T. W. — In publishing photographs like two or three of those forwarded, it would be sailing very close to Lord Campbell's Act. Such works could never be classed as "Artists' studies." They are too coarse and vulgar for that. "Artists' studies," if indecent, will render the producer and venders liable to prosecution. Prints returned as desired. R. T. F.— We know nothing of the people referred to. Carry out your threat to communicate with the local Superintendent of Police. If you habitually read this Journal, you would have seen that we have, time after time, cautioned assistants against sending original testimonials, and have strongly advised them to write their names and addresses ;icro3s their specimens. S. A. G.— The cause of the prints on P.O.P. paper sticking to the glass is that it was not sufficiently chalked, or that the French chalk was not rightly applied. It is not stated whether the prints were aluined or not. But during the very hot weather it is advisable to do so as this treatment, acts as a great preventative of sticking. If the prints are alumed, and the glass rightly treated with the chalk, there will be no further trouble. X. Y. Z.— If the Postal authorities repudiate liability for the injured photo- graphs, on the ground that they were insecurely packed, we fear you have no remedy. 'Two thicknesses of stout brown paper is not sufticient protection for 10x8 prints on plate paper. Such pictures should always be pro- tected with thin packing boards or stout millboards. Possibly the photo- graphs can be soated off and then remounted. This would, to an extent, mitigate the loss. A. Sayers.— It is impossible to say if gelatino-chloride prints are more per- manent than those on albumen paper, as time has not been long enough to test them. There are many prints on albumen that were produced thirty years and upwards ago, that are as good now as when they were first made. Of course gelatine lias only been on its trial for a tenth of that time. Some albumen prints show a yellowne-ss in a year or two, and so have some on gelatine. Time is the only reliable test. H. SroDE. — Several formuhTJ for carbon tissue have from time to time been published, all of which will yield good results, but they require a certain amount of judgment in applying them. As a beginner, we should recommend you to abandon the idea of making your own tissue, or at least until you iiave gained some experience in working the process. It will save you a lot of trouble and facilitate your mastering the process. The advice proifered will apply equally well to the idea of making transfer paper. Druid says : " A friend of mine has a lens bearing the name of a London firm, bearing also the word ' Caloscopic,' but no one can tell us what it is for. The front lens is about two and a half inches in diameter, and like a single land- scape lens, or the front glass of a portrait lens, while the back is much smaller — less than an inch. Tliis is composed of two lenses, but seems to have no focus, yet the thing seems complete as it is. Can you enlighten us on the subject ? "—The lens is simply the old orthoscopic lens under another name— that adopted by its maker. Knowledge is Power writes : " I should be very mucli obliged if you would inform me the best thing to put the card backs on opalines with. It must be free from anything that would act on the prints as the glue I used did, but it wants to set as hard and quickly, so as to hold the back in position without being weighted separately. Gelatine is not tenacious quickly enough." — Gelatine is quite as tenacious as glue, and sets quite as quickly — some kinds much quicker. Evidently our correspondent has tried an unsuitable sample. Nothing will answer so well as good gelatine. A. Z. , who encloses a cutting from an advertisement they are issuing, offering to make "splendid likenesses" from inferior pictures, writes as follows : "As you will see by enclosed, we are making rather a speciality of copying and enlarging. Of course we should not knowingly meddle with anything copy- right, but, as we often receive commissions by post from strangers to us, we might without knowing it happen to get hold of something in this way that was copyright. Should such occur, could you inform us whether we should be liable for the infringement, or the party that employed us ? Everything we send out not from our own photographs bears our name and address, aud is stamped ' Copy.' If you will kindly give us your opiuion on this point, you will greatly oblige." — If our correspondents reproiluoe a copyright picture, they must take the consequences of their act ; the mere stamping of a piracy "Copy" does not relieve them in any way. The only way to protect themselves is to have a proper agreement for indemnity from those for whom they execute the commissions. OONTSNTB, Paob RATIO OF OUADATION 483 vignetting by artificial light 434 PHOTOGRAPHIC CONVENTION OF THE UNITED KINGDOM 486 THE convention EXHIBITION . . 487 RECENT DEVELOPERS. By E. J. WALL 487 LANTERN-SLIDE MAKING. By C. L. MITCHELL. M.D 489 ARTISTIC EXPRESSION WITH THE HAND CAMElt.V. By J. OUARDIA 440 Paoi MULTIPLE FILMS. By S. HERBERT FRY 44a SOME POINTS IN CONNEXION WITH DEVELOPMENT. ByC. H. BOTHAM- LEY. F.I.C., F.C.S 444 NEWS AND NOTES 415 OUR EDITORIAL TABLE 448 RECENT PATENTS 440 MEETINGS OF SOCIETIES 447 EXCHANGE COLUMN 44S ANSTTEBS TO C0RBESP0MDENT8 448 THE BRITISH JOURNAL OF PHOTOGRAPHY. No. 1733. Vol. XL.— JULY 21, 1893. PALLACIES CONCERNING PHOTOGRAPHY IN THE PAST. TiK idess so freely expressed in the paper read at the meeting of the Photojr^phio Convention by Mr. J. Guardia, with regard to the alleged shortcomings of photography anterior to the introduction of dry plates and hand cameras, are but a reflex of those entertained by many others who have only en- listed in the ranks of photography during the last few years The new recruits are too often given to referring to what they glibly term the dark ages of the art, without knowing anything at all of what used to be done in them, and wliat is still possible with what are now classed primitive means. On former occiwions we have found it recinisite to direct attention to the fact that long prior — say, twenty or five-and- twenty years, or even longer ago — to the bnlb-squeezing and button-jiressing era, results, both as regards artistic merits and instantaneous effects, were obtained that have not yet been sur- passed. But the recent paper by Mr. Guardia, reiterating that all the present excellence of photography is due to modern appliances, coupled with the prominence given it through its being read at the Convention, where, of course, the discussion upon it was brief, and even that not reported in full, renders it once more requisite to point out what was actually the case, and what was done, daily, long before their introduction. In doing 60 the prevalent idea with many will, to an extent at least, be dispelled, that all the good work now produced is only possible with modern resources. The author of the paper, referring to the aspects of nature i\a recorded by photography before hand cameras were invented, says it was a " dead maze of trees, and fields, and buildings. The rivers and lakes showed no ripple, they were merely a mass of glaring white. The streets were deserted, and tenant- less houses were but a mockery without reason. The beauty of clouds and atmosphere was unknown — was represented by acres of white paper. Here and there a group of soulless caricatures of human beings were, indeed, to be seen, all stuck up in constrained attitudes ; not breathing, and moving, and ])alpitating with life and energy; but either blurred out of all .recognition, or fixed in unnatural poses, like wax dolls glaring .It nothing, puppets without muscles, and silhouettes without subbtance." This is how photography is described as depicting the world before the introduction of the hand camera. Now, it is perfectly true that hundreds of bad photographs were taken before the advent of the hand camera, and it is equally as true .that thousands, nay, tens of thousands, of bad ones have been taken since ; also that some of the early workers, like many later ones, were ill advised enough to show their inferior work, and even, like many at the present time, to send it to public exhibitions. Most of our older readers will remember the excellent sea and cloud studies of Le Gray, taken something like forty years ago, and those by Colonel Stuart Wortley at a later date. The waves in these were not a mass of glaring white, neither were they devoid of cloud and atmosphere. These ])ictures were not of hand-camera sizes, but fifteen by twelve, or larger, and what is more, if we remember rightly, the former were from paper negatives. Sky and atmosphere, even at that remote period, were not necessarily represented by "acres of white paper." Clouds were frequently printed in, and usually with discretion. It was seldom then that a landscape was seen lighted from one direction, while the clouds were illumined from another. Clouds were then, as now, obtainable in the negative with the subject. Apropos of this point, and the neighbourhood in which the paper was read, we have now before us a couple of stereoscopic negatives of Saltash Bridge, each of which contains excellent natural clouds. The bridge is not here depicted, as it is familiar to the members of the Convention, but is shown with one tube in situ, and the other about midway between th^ ground and its final resting-place, while the piers of the viaduct portion of the structure are seen in course of erection. There- fore the negatives must have been taken in the late fifties. But examples like these were common enough even at that period. Old apparatus is condemned wholesale, and is charged with being designed by incompetent persons such as carpenters and cabinet-makers, and credited with many of the shortcomings (i) of photography before the hand camera. However, many will remember the instantaneous stereoscopic pictures of breaking waves by the late Mr. G. W. Wilson, which have not yet been excelled. The " instantaneous " shutter Mr. Wilson employed was nothing more than his Scotch bonnet deftly used. We have in our mind, while on this topic, a fully exposed 12 x 10 instantaneous view of Regent-street, taken about 18.''>8, which showed the wheels of vehicles, and the feet of pedestrians crossing the road sharply defined. The exposure, we were told, was made by one person uncapping the lens while another immediately thrust a black cloth over it. Those who have seen Mr. Frank Haes' photographs of the animals at the " Zoo," taken something like thirty years ago, and those of Mr. York, of a somewhat later date, are fully 4J0 r.THE BRITISH JOURNAL OF PHOTOGRAPHY. [July 21, 189S aware that they will hold their own against any of the modem work With regard to street scenes, and the like, we have the instantaneous views of Paris by .Mr. William England, and those of London by Mr. Blanchard, and others, produced a quarter of a century ago, that still have to be excelled. These workers, it is true, had not the advantage of more or less com- plicated arrangements for making their exposure^, a.id they worked the "messy" wet-collodion process. The earlier photo- graphs of Muy bridge, and which obtained for him his reputation were also by this, by modern workers, much-decried process. Li whatever direction one may look, it is difficult to see, in modern work, anything that has not its equal in what was done years ago. It must, however, bo admitted that, to accomjilish that, much greater skill was necessary than is the case now ; consequently the greater credit should be accorded to those who were successful. There is no gainsaying the fact that modern dry plates, with their extreme sensitiveness, have conferred a great boon upon photography by enabling it to be worked with greater ease and comfort than was possible with any previous process. They have also permitted the use of more convenient appliances. But for this it must be conceded that the majority of those who now produce excellent work would not have taken up photography at all. This article is not intended in any way, even for an instant, to dispai-age the ability of modern workers, but simply to dispel some of the fallacies that are constantly being promul- gated by many, that the quality of the present work is entirely due to the introduction of modern processes and appliances, and that, prior to their introduction, good pictures were an impossibility. ♦ EXPOSURE, DEVELOPMENT, AND FOG. There can be little reason, after the most recent contributions to the discussion of the question of ratio of gradation, to doubt the correctness of the views held on either side when considered from their respective standpoints, the apparent discrepancies being rather those of expression than of fact. In other words, while Messrs. Hurter & Driffield are, there can be little doubt, correct in their contention that the gradation in a negative is produced by the action of light alone, regardless of the compo- sition of the developer — so far at least as normal conditions prevail — still the practical man is equally accurate in his claim that he can modify the character of his negatives in develop- ment by departing from those normal conditions. The extreme care with which the researches of those gentle- men have been carried out is not more strongly evidenced than by the fact of their recognising the necessity for making due allowance for the effect of the fog, or abnormal reduction in- variably present under even the most favourable circumstances. Such fog, unless varying in the same ratio as the image itself — in which case it can scarcely be abnormal reduction — must necessarily alter the gradation, and Messrs. Hurter &, Driffield in all their experiments have made allowance for the fog in- herent in the film as measured from an unexposed portion of the plate. In making this allowance, they have necessarily looked upon the fog as equally pervading every portion of the film, irrespective of the additional effect of light ; but, as was pointed out by Mr. G. Watmough Webster in the discussion following Mr. Bothamley's jiaper at the Convention, it is questionable whether that view is the correct one. Mr. Webster's contention, as a practical man, is that fog is morc' likely to show itself iu an unexposed plate or in the unexposed portions of a plate than where light has partially acted, while- Mr. A. Cowan, an equally practical man, dissents from this view. Possibly even here, as we shall endeavour to show, both gentlemen are in a measure accurate from the particular stand-- point each takes. It is now some twelve or fourteen years since we first saw an example of this in connexion with a gelatine plate. In the dark room of a well-known professional pliotographer — after- wards a plate-maker — we witnessed the development of ai whole-plate upon which two cabinet exposures were supposed to liave been made ; but by some accident one half of the plate had received no exposure at all. For a considerable time uo' sign of any reduction whatever was visible upon the unexpostd portion of the plate, but towards the close of the development when the solution was finally strengthened for the production of detail and density, the blank half of the plate began to veil,., and, by the time the negative on the other portion was com- plete, dense fog had obscured the otherwise clear glass. At the same time, the shadows of the negative and the rebate of the dark slide on that portion of the plate were perfectly clear, or as near it as the best negatives usually are. It was at firat assumed that the one half of the plate had been fogged by the admission of light into the camera by some- means but that was negatived by the fact of its remaining clear for so long a time, and also by the portion protected by the- rebate of the slide being equally veiled, no less than by the impossibility of such an occurrence on one half only of the plate. Upon due consideration there seemed no possibility of escaping the conviction that the unexposed portion of the plate had suc- cumbed under a greater strain tlian the other half was subjected to. Collodion workers will,nodoubt, remember similar effects, more especially with dry plates and silver development. The latter form of development, iu fact, was particularly liable to abnor- mal action under the least suspicion of under-exposure, since- the soluble silver salt it contained would only remain in that condition for a limited period dependent on the restrainer present ; and when it was deposited, if the exposed portions of" the plate did not exert a sutliciently powerful attractive force to draw the metal to themselves, it had to deposit itself uni- formly over the surface of the negative, whether exposed or not This was notably the case with negatives exposed in a bad light, or with subjects possessing biit little contrast, for if the reverse conditions prevailed, although the plate might have been insuf- ficiently exposed to make a good negative, the brilliantly illuminated portions of the image attracted to themselves more than their due portion of eilver, and thus kept the shadows free • from fog, at the same time producing the eft'ect of harshness. It has occasionally been our misfortune iu these days, when working with a binocular camera, to find on development that' one half of the stereogram had not been exposed, and in such cases the unexposed portion was invariably more or lees fogged,, as in the case quoted above, although the shadows of the other half might be perfectly dear. It seems clear, then, that there is a tendency for fog to appear in inverse ratio to the action of light that has touched the ])late — that is to say, if there be any inherent tendency in the film to produce fog, for it is here where we think Messrs. - Webster and Cowan differ. If the plate be a good one, and quite free from latent fog, and the development be carried on. in a " safe" light, there appears to be no reason. why it shouldi July n, 189a] THE BRIIISH JODKNAL OF PHOTOOBAPHY. 4«I not stand the application of a developing solution of reason- able strength for an uulimitcd^time. But the case is different where a tendency to fo^r exists, for the application of a develop- ing solution of any strength is bound to brin^ it out if allonred sufficient time. That the fog may not make its appearance in the case of a fully exposed negative may depend on differ- «nt circumstances, it may be that the ncgiitive image is •complete before the fog has had time to develop, or it may be held in check by the bromine given off by the reduction of the adjacent portion of the image. At any rate, a foggy plate will undoubtedly often give a clear negative, when it will not remain clear when entirely unexposed. To test the matter, a plate of a brand known to work in a remarkably- clean fashion was exposed in the camera, one half 'being covered with a sheet of opaque paper. The exposure -was such that a developer of full strength iiad to be applied for a rather prolonged period ; ia fact, it may be said to have been under-exposed. After Bxing, however, there was no more sign of veil on the covered portion of the plate than in the shadows of the exjxjsed parts, and the same result was obtained on repeating the experiment with variations. Another plate, of a different make, which usually requires very careful treatment, was submitted to the same test, but in this case the unexposed half of the film was unmistakably and liadly fogged. With tliis make of plate the experiment was varied by exposing one half of a cut plate fully — that is to say, •sufficiently to ensure that it was not under-exposed — and the -other for half the time. The two were then developed in the same dish, and for the same period, being removed when the longer exposed half was sufficiently developed. After fixing, while the latter was perfectly clear in the shadows, the other half, although not showing any great lack of exposure, was distinctly veiled, although submitted to exactly similar treat- ment. In another experiment one of the cleaner, workingjplates was ■ intentionally fogged by a brief exposure to artificial light with . The •Exhibition will be inaugurated by the usual conterfozione and recep- •tion by the President (Captain W. de W. Abney,C.B., F.K.S.) at the - Gallery on Saturday, September 23. Forms of entry and all necessary .particulars are obtainable from Mr. R. Child-Bayley, Assistant Secre- ' tary, .jO, Great Russell-street, W.C. Volatility of Silver. — We recently referred to the experience of one of our correspondents who believed ha lost a large quantity of •■alver by volatilisation when reduing residues, and in connexion with this subject, in a recent number of Compttt Remlwi, M. Moisaan give* an account of some remarkable^ezperimenti in the melting of metaU by the aid of electricity. Whether our correnpondent was right ot not in his belief in the manner of bia loss, it has long been known that silver is volatile, and some of theae experiment* we refer to oooaiated in bringing the silver to a state of ebullition, which was done in • few momenta, diatiHing the vapour, if we may use the expression, and then condensing it in the form of small globules, varying in nze Imn amall shot to microscopically small spherules. Gold also was distilled, the condensed product being in the form of powder exhibiting a beantif nl purple sheen. Hefractory BXetals for FhotOKraphic Use.— M. Moi^ sen's paper contained also accounts of experiments with other metala which were pregnant with interest Taking, for example, molyl^ denum, by the electric furnace he obtained an easily detachable regains of the metal combined with carbon which was of extreme hardneat. This molybdenum carbide is so hard that it scratched glass and steel, and it was not attacked by moist air. If it were posaibie to face the steel plate of a rolling press and burnisher by some such material as this, the plate would be invaluable, for there can be no doubt that many an imperfectly glazed or surfaced print can be traced to the use of a steel plate, which, through long use or accident, has lost its original burnished surface. Possibly, also, ziroonia cylinders for the optical lantern might be obtained by means of the electrical furnace; for M. Moissan was able to reduce this earth to vapour, and condense it into a fine white powder, the individnal particles of wbidi were hard enough to scratch glass. Action of Ziierlit on Cobalt.— Messrs. Augnste & Lotus Lumiere are continuing their experiments in this direction, and, in the journal above quoted, describe a process founded on their previous discovery that cobaltic oxide is rapidly reduced to a cobaltoos salt when exposed, in presence of organic matter, to the action of light. They impregnate paper with a cobaltic compound, expose to light undtT a negative, and by means of certain reagents — preferably potassium ferrocyanide — bring out an image. AuiattUitsaiidTlieir Specimens. — Numerous complaints of the detention, by photographers advertising for assistants, of the specimens and testimonials submitted to them by applicants are again reaching us. We should scarcely have been surprL-«d at this had we not previously dealt with the matter on several occaaons, denouncing the dishonesty shown on the one hand, and the stapiditv and carelessness on the other. W^e again strongly advise operators or assistants when submitting specimens to write their names and addresses on some prominent part of the photographs. This will prevent improper use of them by unscrupulous persons. Again, copies of testimonials only, and not the originals, should be sent. In neglecting these precautions assistants are largely to blame in not securing the return of their specimens and testimonials. As for those photographers who male a practice of wilfully not returning specimem, &c., submitted to them, we may remind them that we have a black list in which their names are entered, and which we use in the interests of defenceless assistants. Pbotogrraphle Stvdy of Sources of &irht. — M. Janssen first made a special study of this subject bv photographing the solar surface with exposures of gradually diminishing length. M. Crova has applied the same method to the standard Carcel light and the electric arc. The true proportion of the constituent parts of the flame to one another is only seen when reduced exposures are given, four such photographs having lately been shown at a meeting of the French Academy. The flame was shown thus to be divided into several zones, separated by distinct lines of demarcation, and «inn»1«T photographs of flames of a candle, an amyl-scetate burner, and a batswing jet exhibited similar phenomena. Most interesting phe- nomena were observed when the image of the electric arc was examined on the groimd glass of the camera. The positive carbon showed a 452 THE BRITISH JOOKNAL OF PHOTOGRAPHY. [July 21, 183.3 surface riddled with dark spots, and granulated like the surface of the sun in M. Janssen's photographs, the granulations being distinctly ob,served in a state of violent motion on the ground glass. The important deduction is drawn that, in estimating the potency of these light surfaces, it is not admissible to screen off all but a very small portion of the luminous source in order to reduce the amount of light in the same proportion as the area of the luminous surface. With very small surface elements, both the amount of light and the temperature, and hence, alao, the tint of the light, may be constantly changing. Kew Focussing' Arrang-ement.— The advances made in the construction of the camera proper and the mechanical motions in connexion with its working have apparently entirely displaced the rack and pinion in lenses of very long focus. Few photo- graphers of the present day have ever seen, for example, the once-used Hook's Universal handle for turning the pinion of the lens when the latter was placed at a considerable distance from the ground glass. It was a very useful addition, the pinion projecting through the milled head to form a square head on which the handle fitted, and the joint itself was a most ingenious piece of mechanism, which might with advantage be utilised for modern work. There has, however, been recently invented a focussing device which is capable of advantageous practical appli- cation to the huge portrait cameras so much to the fore of late years. The first practical application of the device has been to the eye- piece of a five-inch trletcope belonging to Mr. Beach, one of the proprietors of the Scientific American, and it has been found to answer its purpose most admirably. Briefly, it consists of an attachment to be applied to the sleeve of the rack and pinion of the lens, to be moved to and fro for focussing, and when not in use does not interfere with focussing in the ordinary way. An ingenious and not too complicated mechanical arrangement works two levers, which are actuated by a pneumatic pear, and the motion is so com- municated as to work the pinion in a forward or backward direction as required. We have not yet heard of the device being applied to photographic lenses : but, as it appears to possess such advantages over ordinary means for large instruments, there seems every proba- bility of the adaptation taking place. » CONVENTION NOTES.— I. It was feared by some that, owing to the geographical i-ituation of Plymouth, the Convention would be but sparsely attended this year ; but, although its distance certainly prevented some hitherto regular frequenters of its meetings from being present, yet, all things con- sidered, it was well attended, several having come from Belfast, Dublin, Glasgow, Liverpool, Manchester, Chester, Derby, and localities not less distant, not to speak of London. The kindness of Plymouth, in which we include Stonehouse and Davonport, could not possibly be surpassed, and the attention be- stowed upon the visitors by the brethren there will not readily be forgotten. Plymouth and its environs team with delightful subjects for the camera, but tliose who go there for pictures alone have not the same chance of obtaining them during a busy Convention week that thev would have were a quieter time selected, when they could go where- ever they pleased and stay as long as they preferred. There is much of historical interest that centres in Plymouth. None now need to be told that it was in this port— at that time the chief naval arsenal of the kingdom— the English fleet lay in waiting for the appearance of the Spanish Armada ; that it was from Plyt mouth the great colonising expeditions set out, one of which annexed Newfoundland ; that from here, over 270 years since, sailed the Mayflower with the Pilgrim Fathers who founded the American Republic ; much less do t'ley require to be told that in the Ilamoaze, an important estuary in the immediate vicinity, lie peacefully slumbering at anchor a mighty navy, replete in every respect with everything that can conduce to destruction — formidable ramming warships of the latest construction, numerous torpedo vessels — all reposing side by side with specimens of the " wooden walls of Eng- land"— the once formidable Timeraire among them — spending the evening of their existence as training ships. The town of Plymouth is neat and clean and its streets are busy. In several druggists' shop windows are sjen the inevitable camera, mainly of the ''hand" genus, with announcements as to pliotographers, requirements being procurable within. The windows and interiors of two photographic establishments in George-street, those of Mr. Heath and Mr. Hawke, are wortliy of examination on account of the real ex- cellence of the numerous portraits — largely of members of the Koyal Family — there exhibited. Mr. Yeo, too, who lately obtained a medal at the Pall Mall Exhibition, has a fine exhibit at his gallery. Indeed, all through the town the works exhibited by photographers are equal to any we have elsewliere seen and are superior to those in many large towns. The group which we issue with the present number was taken by Mr. K. L. Kidd. Mr. Kidd deserves special commendation for the enterprise displayed by him on that occasion, for after developing and drying the negative it was despatched by him to his works at Kich- mond, where it could not possibly have arrived till the forenoon of the day following (Thursday), and yet on the morning of the succeeding day (Friday) numerous copies, printed on bromide paper and mounted with a sunk plate mark, were on exhibition in Plymouth ere the memljers of the Convention had breakfasted. The print we give, however, is not a bromide one, but is printed by the firms' collotype process. Apropos, the members of the Convention portrayed in the group do not by any means represent all who were present at the meetings, nor, for that matter, all who were present when the group was taken, for the temptation to have a "shot " at their fellow-members proved too great for resistance by several who had their cameras, and who " blazed away " regardless of the fact that they themselves would inevitably be left out in the cold. At the Convention dinner oni Friday, a largo, and what may be designated the official, group, taken by Mr. W. Heath, was placed on exhibition. We had only a hurriedi look at it, but it seemed to us as being absolutely faultless. Is it not a mistake in the Cjunsil to receive sucli a large number of papers to be read ? It is altogether impossible that every one of these can be brought before the notice of the meeting. Imagine three or four, or even half that number, of long papers on topics- more or less important being brought before a stance, which can last at most but an hour or an hour and a half; and this, too, after a day pretty actively spent in other Convention duties ! A I'resident. would be something more than human if he could curtail discussion on any one of these to, say, half an hour, and then what is to become- of the other papers yet in store, and down on the programme for that evening's proceedings? The system usually adopted is, doubtles-", the best, viz., when the usual hour of separation has come, to tike those papers as read the authors of which are not themselves present. In our last issue we gave all those that were really read ; in present and succeeding numb^Ts we shall give all thosj whic''. having been actually read, were taken as such. th» , not GELATINO-CHLORIDE NOTES. Much doubt and difficulty appears to exist in connexion with the mounting of gelatino-chloride prints, though why it should be so, if the instructions were carefully followed, is not clear. The new paper,. July 21, 1893] THE BRITISH JOURNAL OP PHOTOaRAPHY. 4ra of course, requires some little different treatment^from that given to albumonised, but those who have become accustomed to the latter refuse to changre their habits. The most important jx)int is, of course, the use of the alum bath, which should never be omitted, however little tendency to softening the film miiy show, but it sliould always be used last thing after fix- ing and well washing. When so applied it forms, in addition to hardening the gelatine, a safeguard to the permanency of the print, and the trouble involved is not worth counting. It should never be used before toning, as recommended in some of the instructions, for it not only leads to irregularity of tone, as mentioned in a recent leading article, but, to my idea, spoils the tone, or, at least, renders it difficult to get the rich tones otherwise obtainable. But I would go further than merely insist on the use of alum, and would make a point of invariably drying the prints before pro- ceeding to mount them. This completes the hardening process, and removes any last traces of "stickiness" their surfaces may have, and even when rewetted they are no more difficult to handle than albumen. Instead of mounting the prints direct from the last washing water, blot them off and lay them out to dry in a warm room, which will not take very long at this time of year, and they may be finished off at the fire. If they are properly alumed, there is not the least danger of their sticking to the blotting-paper or of " fluff " adhering to them. Then, before mountii^, soak them in water again to soften and swell them, and proceed. Tlie drying before mounting is, of course, a necessity if the prints are not trimmed to size before toning, and even in the case of cut sheets the operation of trimming has to be performed at some stage It puzzles me to know why the manufacturers send out cut sheets the e.xact size of the negative instead of a quarter of an inch smaller each way. The margin has to be trimmed off in any case, unless the finislied prints are to be improved by being mounted with a black margin, representing the rebut of the dark slide. There is, however, one advantage, namely, that the edges of the print are cleaner after trimming before mounting than would be the case if cut sheets the exact size of the final prints were used, for then the handling in the course of manipulation is liable to loosen the gelatine and cause ragged edges. As to the style of mounting, let those who like the "bon-bon-box glaze continue to use plate glass, and allow the mounted prints to dry before stripping. But, for oidinary purposes, ebonite or ferrotype plates will be found better. The latter, indeed, if of the best quality, have a surface little inferior to glass. Some of the papers on the market now, however, require no squeegeeing on to glass or anything else, but dry with a surface equal to superior albumen prints when mounted in the same manner, though they are improved by burnishing, which is an operation beyond the reach of most amateurs. Celluloid, however, is my favourite where a squeegee support is used, and either sort of surface— matt or polished— can be got, ac- cording to the side of the celluloid used, the prints stripping as easily from the smoothed or grained side as from the polished. The trans- parency of the celluloid is aL-o an advantage, especially when the plan of mounting to be described is adopted, and it is one I have found very convenient. I have sheets of celluloid cut to the exact size of the prints when ready for mounting, and the damped prints are squeegeed on to these. ITie celluloid sheets may, in fact, be utilised as trimming shapes, the untrimmed print being squeegeed in contact, and then cut to the exact size with a pair of s/iarp scissors ; in fiict, this is the more con- venient plan. This having been done, the back of the print is starched or gelatined, and together with the ceUuloid placed on the mount and left to dry. There is no danger of the prints sticking together if placed in a film under pressure ; indeed, thev are all the better for such treatment. When quite dry, the celluloid' comes away easUy, and is ready for another batch of prints after polishing with talc or wax. If I might make a suggestion to the dealers in photographic goods. It IS that they should send out cut sheets of celluloid prepared for thU purpose with rounded comers. If put up in packets of a dozen, I should think they would be opprtciatcd. VV. B. Bolton. MY FIRST DAOUERUEOTVPE.* In process of time my lessons came to an end and I was supposed to be ready for operations on my own account. I had done a great amoimt of buffing and had seen the rest of the operations verjr frequently, but had actually never completed a picture without assistance. I had not money enough to build a studio, but my friend assured me that the Americans preferred a large window to tke top light of a glass roof, and he bad been fortunate enough to secure a large room with a few windows, and in this ready-made studio he produced portraits the lighting of which could not be surpassed even now. I searched far and wide for a suitable locality, but found not one with the much-desired bow windows, and finally had to be content with a large upper room over a shop. There were two windows, but by darkening one I thought I might be able to manage with the other. I had a north light, and that was at any rate .something in the right direction. For many days I was busily emploved in fitting up my dark room, and in other ways getting ready for the serious operation of admitting the public, who would without doubt rush in with the money in their hand eager to pay in order to be practised upon, and this eager anticipation and active work made time go like lightning. At length I deemed the place ready for work, and proceeded to try my apparatus. I had no trouble with the buffing, and the faultless plat"?, with its black polish, was first put over the iodine vapour, and then !>]ld on — when the right change of colour had been obtained — to the bromine compartment. Apparently all went well, and the plate had success- fully passed through the various changes of colour then deemed necessary for the highest state of sensitiveness, and I exposed my first plate on a plaster copy of the " Greek Slave," for in her I had a model I could trust not to move. I gave what I judged to be the right exposure, and with great eagerness watched the dawn of my first picture. Alas, there was no dawn for all remained night, and the fair slave was still captive, hopelessly imprisoned within the fair film of the sensitive plate. Surely, thought I, a white subject must make some impression if every operation had been correctly carried out, and I proceeded to prepare another plate. I felt certain I had removed the cap of the lens, but doubtless I was in error on that point and must therefore be more particular next time. Needless to say that, at the next experiment, every possible pre- caution was taken to ensure success ; but, alas ! it did not come. The plate was lifted from the mercury bath more times than I can count, but still no trace of an image whatever. In my lessons I had been taught that something dreadful would happen if I exceeded the regulation time in the bath. I became desperate, and dared every- thing. The time was doubled, and again doubled, but still no picture. I had been told that something equally dreadful would result if I increased the temperature beyond the fixed limit. As desperation increased, 1 recklessly pulled up the wick of the spirit lamp, and ended by bursting the thermometer. It was not made for very exalted temperature, so what could it do when the mercury filled the tube to extreme limit but crack its sides? Clearly there was nothing more to be done that day but rush off to my tutor and cry out for help. He could offer no explanation, but promised to come over at the close of the day and examine matters for himself. I rushed off to buy a new thermometer, but found I could get none of the pattern needed that would record very high degrees of heat. When I ex- plained ray difficulty, the assistant assured me that the instrument was more than sufficient for my requirements. When I reached home — for my studio was " kitchen, and parlour, and all '' — I made the patient slave submit to three more exposures, varying in duration, and this she did with stony indifference. In due time my friend appeared, and, after a careful examination of all my arrangements, he proceeded to develop the exposed plate. Failure attended his first and second efforts, and then he declared that it was absolutely impossible that I could have exposed the plates. I might have taken off the cap of the lens, but I had failed to pull up the slide. I assured him that I had pulled the slide entirely out, and shut down the lid of the camera, and had held the metal slide in my hand as well as the cup of the lens, in order to be perfectly sure of my proceedings. lie scratched his head at this, and then an idea struck him. The mercury was oxidised, and wanted filtering. Had I a piece of chamois leather ? I rushed out, and in a few minutes had procured a piece, and then the mercury was duly filtered and replaced in the bath. The last plate was tried with the mercury, as recorded by the thermometer, far above the extreme regulation limit, but with the same negative result, so my instructor in turn wa!% hope- lesfly beaten, and was compelled to admit he could offer no explana- tion of the mystery. * Oonclnded from page 424 454 THE BEITISH JOURNAL OF PHOTOGRAPHY. [July 21, 189a He departed, and I was left alone with my own gloom}* thoughts Was this, then, to be the end of all my efforts — ignoble failure ? Were all the bright anticipations that had buoyed me during all my exertions to be submerged in this "Slough of Despond?" Surely this was a fitting reward for my overweening conceit; for, like many other beginneis, I never fur a moment doubted myself, and though I had not been furnished with as much practical work as fairly belonged to me during my period of tuition, I felt that, once started and left entirely to my own resources, I should find no difficulty whatever. The veil was removed from my eyes — indeed, torn from them bj' this utter collapse. The next morning I was at work before breakfast, hoping against hope that my luck would change. The Greek Slave once more endured the audacious gaze of the lens, but the plate remained proof against her charms, I left it in thc^ mercury bath, and tried to drown my trouble in a cup of tea. I could not eat, but tried to forget my troubles for a moment by reading. The subject of the book caught hold of my mind, and held it for how long I cannot say ; but all at once the remembrance of the plate in the bath came back, and I rushed eagerly into the dark closet. The lamp had flared up unusually high, and the thermometer was again broken. With fear I lifted up the plate, but, oh, joy ! there was my first Daguerreotype. There was the fair Greek delineated with a purity and beauty I had never seen before. Surely such a Daguerreotype had never before been offered to the gaze of man, for to my gladdened eyes it was indeed beautiful. The key to the enigma was at length furnished. The mercury baths of American manufacture were wonderful examples of fine iron casting. Mine was a clumsy imitation, and almost a furnace was needed to get up the necessary heat to properly vapourise the mercury ; the bottom of the bath was cut down to the necessary thinness, and my first great photographic trouble was at an end. Valkntine Blanchahd. JOTTINGS. 1 SKE that the next meeting of the Convention will be held in Dublin. Writing on the subject twelve months ago, I suggested that, in the event of the Home Rule Bill being carried, the title, " Pliotographic Convention of the United Kingdom " would stand in need of altera- tion. The Bill seems to be in a fair way of becoming law before long, and I therefore hope the Convention Committee are prepared with a new title. lieading through several accounts of the Royal Wedding and its incidents, as published in the daily papers, I came across the now stereotyped references to the " inevitable " photographer, the " ubiqui- tous " Kodaker, and other sneers of a similar nature. Why the photographer should be singled out for reference in this manner on «11 festive occasions passes my comprehension. To my thinking, photographers taking views of great historical gatherings, cfcc, are placing posterity under an obligation to them, and be the results never so poor, it is to be hoped that, in the interests of historical accuracy, ■as many of them as possible will go down intact to future centuries. Ridiculous writers in daily papers, however, do not think of this : in trying to be funny or smart in their references to photography, they too often only succeed in being foolish, as witness their sempiternal denunciation of process reproductions of artists' drawings, process illustrations in magazines, &c. On that point I am glad to notice that Mr. Henry Blackburn emphasises the fact that the faults so loudly complained of by the daily press critics are not those of photography, but of the artists themselves in not preparing their work according to the requirements of photo-mechanical workers. It is singular that topics such as those headed " Depression in Photography," and " Amateurs and Professionals," which are just now in course of discussion in your pages, should crop up at a period of the year when one would imagine professional photographers wanted all the time they could get for looking after their businesses. Apparently, however, a great many of them have no business to speak of to attend to, so that they take advantage of your kindly columns to proclaim that fact to the world, to assign causes therefor, and to discuss more or less plausible remedies for bettering their condition. CMef among the causes generally assumed for the undoubted depression in professional circles is the growth and influence of amateur photography. There is, I fear, no denying the fact that there [ are thousands of amateurs who do landscapes, groups, architecture, copying, printing, toning and fixing, mounting, &c., quite as well as the average professional, and whose work, being gratuitously dis- tributed, is bound to act as a deterrent on the general public patronising professionals. Do we not all prefer something for nothing instead of paying for it ? Then as to portraiture, the professionals' chief buttress and support. It is all very well to sneer at the portrait productions of amateurs as being crude and poor, but this does not apply in nearly all cases, for in this branch of work there are undoubtedly large numbers of men who, in posing and lighting, provoke and justify comparison with an average professional, and whose productions, be they good or bad, please and satisfy their friends, and so prevent the latter from going to a professional. All this, and more, tells against the professional, who, I am bound to say, in a great many cases is either too ignorant, too careless, or too poor t; keep himself abreast of the times in taste, novelties, new processes, and all reasonable means for attracting and retaining public patronage. What wonder, then, as one of your correspondents neatly puts it, that he should " suffer through the laws of political economy ? ' The struggle for the sur- vival of the fittest is going on iu photography as in everything else, and at present it looks as if the lower grade professional, the man of limited capital and limited knowledge, will have to go under. The " tin-type " man and the " large direct man " seem to flourish well enough ; the middle-class man is apparently being squeezed out of existence. All the talk about licensing and boycotting amateurs, making them pay more for material, &c., is simple waste and nonsense, and to think that any considerable number of them will refrain from photographing their friends, their o.xen, their m lidservants, and their other belong- ings because it might injure some professional unknown is nearly as bad. I take too pessimistic a view of the matter to suggest any remedies. Professionals might combine — but they won't ; they might abstain from cutting each other's throats in the matter of prices — but they don't ; they might, as a rule, turn out better work — but they won't. They will not help themselves, so how can anybody else help them ? The only hope that I can give them is a poor one, and that is time ! Time rights all things^or some of them. In course of time the great amateur craze may die down, and then tlie poor pro- fessional will come to his own again. But pigs might fly if they had wings. In the meantime I should like to say that I and many of my friends and thousands of others have for years grown our own potatoes, our peas, our lettuces, and other succulent vegetables, and still the greengrocer's remains a flourishing trade. The greengrocer usually is a good man of business, and — must I say it ? — your photo- grapher usually is not. It is a pleasure to note from time to time, among the lengthy commonplace records of the commonplace doings of the photographic societies, little items of news indicating the existence of a desire to impart to their members objective photographic knowledge. The Birmingham Society, for instance, set an example at its last reported meeting which merits imitation on account of its undoubted practical value to photographers, especially amateurs of limited experience. A series of negatives taken by the members on an excursion were staged for examination, and appear to have had instructive effects on those present. If particulars of plate, exposure, stop, developer, &c., are given, no better method of imparting a lesson in development could be given, and it is in the hope that the Birmingham Society's lead will be followed that I venture to applaud it. Different methods of intensification, reduction, and other processes might also be demon- strated in the same way. Cosmos. STEREOSCOPIC PHOTOGRAPHY. X Replv to " Tkchni;jUB." [Road at tho Stereosoopio Club, July 5, 1893.1 SiNCK the last meeting of this Club there have been many things done and published on photograpliic matters that might well occupy our attention as fit subjects for discussion. At tie present time I July 21, 189a] THE BKITISH JOUKNAL OF PnOTOGRA-PHY. wish to call your attention to an article on " Stereoscopic Photo- graphy" pubhsliiHl in the April number of I'Aotoyrn/thic Scraju over the name of " Technique." As most photopfrnpherf arn aware, PAofo- (fraphic 5<,/y(/w is a private journal, published monthly, under the control of the Rritanuia Works Company, and " Technique" is their editorial contributor. No doubt many of our members liave read the article in question, but by this time may liave forgotten nuich of tlie particular statements it contained. First of all, " Technique " is of opinion that the headinjr of his article — " Stereoscopic I'liotography — would have eiven " greater gratification " to readers of photographic literature thirty years ago than to readers of the present day. If he infers, as I presume he does, that there were more amateur photographers interested in the stereoscope, or more stereoscopic cameras in the Held, at that time, then I must bog to differ, since I believe there are more stereoscopic photographers (amateurs) to-day than tliere ever were, and I shall be prepared to submit some particulars and to argue my own case before a committee of three gentlemen, and to back my opinion to the extent of a very good dinner for the committee, " Technique," and myself. Next we are told that the stereoscope did give a great impetus to photography at the period alluded to (thirty years ago), and that "there were abundant reasons for this; not the least was the apparently wonderful character of the pictures, which it was imagined were only possible as photographs, whereas in reality very good stereoscopic picture-? can be made by pen or pencil by any one understanding the principle of the stereoscope and of perspective drawing." Now, if a tyro in photography had made such a statement, it would have been excusable, from the fact that he had not studied the sub- ject : but when a professional scribe, one who writes on scientific matters for the guidance of others, and who sets liimself up as an authority, displays such total ignorance of the subject, then 1 say there is not much room for excuse. As a matter of fact, there has never been an artist clever enough to maice " a good stereoscopic picture by pen or pencil," and nobody who understands the principles of the stereoscope would be so foolish as to try. It is quite true tliere are outline designs — geometrical figures in white lines on a black ground — made for the stereoscope, but to call these "good stereoscopic pictures, drawn by the pen or pencil," would be a deliberate intention to mislead. If we leave out of the question the absolute impossibility of making two pictures stereoscopically dissimilar, and therefore ignore the whole principles of binocular vision, I say again there has never been a man born who could make two pictures so near alike as not to have their differences detected by the stereoscope. The stereoscope is used as a test for suspected forgeries in bank- notes, a photograph of a g<)nuine note being placed in the instrument along with another photograph of the suspected note, and a difference in the engraving so slight as not to be detected in any other way is at once made manifest by the stereoscope. Next we are treated to some historical matter which is equally in- correct ; and, as " Technique " would have been a very little boy at the time alluded to, I must remind him that dry plates were not intro- duced commercially at '2s. '2d. per dozen for half-plates, I remember paying 12s. per dozen ; so that the price of commercial dry plates had nothing whatever to do with either the popularity or the decline of the stereoscope. Next we are told that " one great complaint that always clung to stereoscopic pictures was the smallness of the view and the extreme minuteness of the object, not all subjects being alike suitable subjects for the stereoscope." With respect to size, it has been demonstrated in this Club that when these small pictures are viewed by properly constructed instru- ments we get the apparent natural size of the object, and there were properly constructed instruments even so far back as twenty-five years ago. I admit that thousands of improperly mounted pictures have been placed upon the market, and long-focus stereoscopes were intro- duced with a view of meeting the defects in the slides ; but because this was done for commercial gain, or by those who do not under- stand the principles, is no sound argument against the stereo- scope. To say that " all subjects are not alike suitable for the stereoscope " just amounts to saying that all subjects are not suitable for binocular vision, or that, to look at certain subjects in nature, we should close one eye, wliich everybody will admit to be ridiculous. A comparison is then drawn in favour of the " pleasure of turning over the leaves of an album and the efforts and the trouble of twisting about to peer into a stereoscope." This is rather funny, for, as a rule, amongst my photographic tnewU I don't often find many albums worth looking at ; but I have taken some trouble to produce a decent one, and I have tried the experiment scores of times by giving my friends first the album, whicii they usually finish with in about ten minutes. After this I give them the very same pictures by the stereoscope, and these excite their admiration for an hour. But, continuing, we have another comparison between the " selflsb stereoscope" and the "popular lantern sUde." Well, as regards selfishness, the same argument might be used against the microscope, but it would not detract from the merits of the instrument. I re- member reading somewhere that a stereoscopic slide was always in season, daytime or night, winter and summer, in company or alone, and we cannot say so much for a lantern slide ; besides, I wonder it it ever occurred to "Technique" that from stereoscopic negatives lantern slides were just as easily made as from quarter-plate negatives, and very much easier than from half-plate or larger-size negatives, or did it ever occur to him that a stereoscope could be passed round amongst a few friends, or that two or three stereoscopes were possible to be in use at one time when friends were present ? Next we are told that " the majority of stereo slides are printed on paper and mounted on cards," and another comparison unfavourable to such stereoscopic slides is given bv showing the rapidity and con- veniences of printmg lantern slides. Now, here again, " Technique" has overshot the mark, for, so far as amateurs are concerned, only a very few make paper slides, because stereo transparencies on glass are so much easier to produce. Quite recently I had the honour to adjudi- cate upon a stereoscopic slide competition organized by the editor of the Amateur P.'totor/rapher, and out of twenty-three competitors only four sent paper slides. The other nineteen sent glass trans- parencies ; but, apart from that competition, I happen to be in perhaps the very best position to know what amateur photographers are doing in stereoscopic photography, and I do not think that more than five or six per cent, of them make paper slides. But now we come to some personal e.vperieyice of " Technique," who tells us that he has made stereo pictures by a quarter-plate camera at two operations, " the camera being placed upon a simple arrangement known as Latimer Clark's parallel bars, which permitted a side-to- side motion of the camera in order to obtain the requisite angle for stereoscopic effect." In reply to this, it must be said that Latimer Clark's " parallel bars " do not permit any angle at all, they keep the a.xis parallel; some modifications of this arrangement were made in years gone by, and these did permit an anijle, but they were wrong in principle and in practice too, and the difiiculty complained of, by the two halves of the negative being unequal, is just what might have been expected by anybody who had studied the subject. But " Technique " concludes his " personal experience" by his observance of these and some other defects in a number of slides published in the Stereoscopic Magazine of 1862. The next paragraph treats of " the number of people who cannot see pictures stereoscopically because there is something wrong with their eyes." This is a tale I have heard hundreds of times, and in at least ninety per cent, or more I have had the pleasure of proving that it was not their eyes that were wrong, but the badly mounted slides or the defective stereoscopes that caused all the trouble. Here is a case in point. Just a little time before this article from the pen of " Technique " was published, Mr. John Howson, the managing director of the Britannia "Works Company, called upon me, and, in the course of a very pleasant chat on general photographic matters, he told me that he had never in his life been able to see a stereoscopic slide stereoscopically by a stereoscope because there was something wrong with bis eyes. " They are not of equal foci," he said. " Oh, is that all?" I replied, and I examined his eye-glasses. Seeing they were about like my own, I picked up a stereoscope from the table, and the first stereoscopic slide I could put my hands upon. After adjusting the instrument to my own sight, I handed it to Mr. Howson, saying, " You ought to see that; " and " I do," he replied, " I never saw any- thing more beautiful; show me another," &c. In conclusion. Air. Howson paid me a very pretty compliment. But " Technique " has a most wonderful control over his optic axis that leaves both Mr. Howson and myself in the shade, for he states that he can not only see slides stereoscopically without a stereoscope, but that he can " look at them from top to bottom of a window in Cheapside or Regent-street, and see every one stereoscopically at six inches to ten feet distant." I admit there are a few people who can see slides stereoscopically without a stereoscope, but, out of a good many people who stat« that they can do this, at least ninety per cent, are mistaken. Inste.id of seeing the right-hand picture with the right eye, and the left-hand THE BRITISH JOUEXAL OF mOTOGRAPHY. r.)ulv21,1803 picture with the left eye— which, with slides mounted at three inches centre would entail a considerable divergence of the otitic axis— they really see the right-hand picture by the left eye, and the left picture by the right eye ; this is done by converging the optic axis (squinting), lius they see" the very opposite to stereoscopic, \\z,,pseudoscopic. But, in either case, stereoscopic or pseudoscopic, pictures viewed in this wav— without a stereoscope— look very much smaller than they really are, and by the stereoscope they look larger than they really are. But to be able to see slides stereoscopically at six inches or ten feet distance, as " Technique " says he can, is a most extra- ordinary performance ; and, it the proposed comraitt»'e and the dinner be arranged, I should like to have something extra on that. Finally. " Technique " sums up the " essence of his remarks " by advising his readers to put their money in monocular cameras, and get as much solidity and relief as they can. Now, allow me to sum up the essence of his remarks. I could do it best in two words, but will manage it in one word — Pbkjudtck W. I. Chadwick. SOME POINTS IN CONNEXION WITH DEVELOPMENT. Thr tables given by Mr. Bothamley (page 445, .fuly 14) are well calculated to show the power of control in development, but are mis- leading when the effect of fog is considered. From the following paragraph it seems to be assumed that, because in the second case an alteration in column 1 has produced an alteration in column 4, that therefore any other alteration will produce a similar result. " Since to add a constant quantity to the terms of a ratio diminishes the ratio, it is clear that the fog will lessen the ratios of the opacities." • Now, it is quite possible to alter column 1 without making any difference whatever in 4, but this can only be done by adding equal amounts to column 1, e.'cactly what is done by adding fog, and the ratios of light transmitted remain unaltered. Tables 1 and 2 are as given by Mr. Bothamley (correcting the mis- prints in column 4), and 3 and 4 are the same with fog added. 1. 2. Thick- netw of the silTer layer. Ratios of the densities. Light trans- mitted. Ratios of the Ught trans- mitted. Thickness of the silver layer. Ratios of tho densities. Ratios of the light trans- mitted. 1 1 i 8 2 1-0 i 8 2 2 i 4 8 1-5 h 4 3 3 i 2 4 20 iV 2 4 4 iV 1 6 2o A 1 8. 4 . 2 1 i 64 3 10 i 64 4 2 A 16 5 1-66 aV 16 6 8 A 4 7 2-33 iU 4 8 4 ^ 1 9 3 00 zh 1 From the above we see that the only effect of fog is to reduce the amount of light transmitted in a given time, the gradation remaining unaltered. J. Stebhy. ♦ PHOTOGRAPHIC CONVENTION OF THE UNITED KINGDOM.* The following papers were taken as read : — LATITUDE IN EXPOSUBE AND SPEED OF PLATES. By F. Hurtek, Ph.D., and V. C. Deiffield. It is generally assumed, because onr researches have led us to pronounce exposure and not development to be the determining factor in photo- graphy, that therefore the production of similar prints from a series of negatives which have received widely varying exposures, and have been Bubmitted to widely different treatment in development, totally upsets ibe whole of our conclusions. Onr attention has been called from time to time to Buoh series of negatives, and, in all the instances which have come to our notice, there bae been no difficulty whatever in arranging the negatives in the order of * Continued from last number. their exposures, nor has it been much more difficult, by mere inspection, to so arrange the prints. If, however, such negatives be measured, and their density ratios ascertained, the order of the negatives, with respect to duration of exposure, is readily decided beyond all possibility of error. As an instance of such a series of negatives we give our measurements of four plates, sent to us two years ago by a gentleman in Ireland, as an illustration of the latitude in exposure obtained by appropriate treatment during the operation of development. The subject was the same in all four plates, and consisted of a field bordered by trees. In the middle distance was a grey house, one side of which was illuminated by the diffuse lij^ht of tlie sky, and the other side by the sun. We measured the densities of the sky, the two sides of the house, the most transparent shadows in the trees, and a spot in the grass. In order to ensure the measurement of precisely the same spots in all four plates, masks with circular openings were fixed on each negative, so that the circles coincided when the subjects coincided. The four plates respectively received ex- posures of 1, 10, 30, and 60 seconds, and the resulting negatives yielded prints differing so little in quality that they were deemed to have com- pletely demolished our contentions. The following table gives the results of the measurements : — Densities. Exposures. Dsrkcst shadow in trees , House (shadow side) ... Grass House (sunlit side) Sky 1" 10" 30" •378 •558 -973 ■833 •750 1-371 •930 1005 1-706 1-721 1-571 2 121 2-598 2-236 2-578 1-028 1-315 1-581 1-921 2-308 A glance at the densities of these negatives, particularly those indi- cating the extreme range (darkest shadow and sky), shows how widely they differ from each other ; whilst a glance at the negatives themselves surprises one by revealing the inability of the eye to readily appreciate these differences. The eye is still less capable of appreciating the great alteration in the density ratios given in the next table. Density Batios. Exposures. 1' 10" 30' 80" Darkest shadow in trees ... House (shadow side) Grass 1 2-2 2-46 4-55 6-87 1 1-35 1-81 2-84 4-04 1 1-40 1-75 2-17 2-65 1 1-28 1-53 1-86 Sky ■24 These ratios decrease with increased exposure in perfect accordanoe with all our experiments. The negatives are very different indeed in this respect, and fully bear out our contention that the density ratios are a function of (he exposure, and not of modifications in development. We have no hesitation in asserting that such negatives may always be arranged in the order of their exposures by any one acquainted with the subject. In printing quality, as regards time, these negatives also differ considerably. It is clear, therefore, that these negatives do not illustrate in a very striking manner what they were intended to illustrate, namely, the great latitude in exposure. They do, however, illustrate another point, namely, the great latitude there is in the quality of prints accept- able to the eye, and the carious iuabiUty of the eye to judge numerical values of density differences. In this faulty perceptive power of the generality of eyes lies a great deal of the latitude of exposure. Various authorities give wholly different limits for this latitude in ex- posures. Professor Burton has given it as 1 : 30, but states that he has succeeded with some plates with exposures ranging from 1 : 80. We ourselves stated in our original paper that the plates which we used in our experiment! (Nos. 21 and 22) would have given good pictures of sub- jects with contrasts varying from 1 : 80, though the exposures had varied from 1:2; that is, the plates were capable of recording truly contrastB ranging from 1 : 60. Latitude in exposure depends — (1^ Upon the quality of the plate. (2) Upon the range of contrasts in the subject. (3) Upon the degree of truth with which the contrasts are to be pre- sented in the positive print. July 21. IW).^ THE BRITISH JODKNAL OF PHOTOGRAPH V. 457 The quality of the plate is the most important qnostion. There are «ome plates which have no latitude of exposure at all, or which are, at any rate, incapable of rendering any range of contrasts in this subject with any degree of truth, whatovor exposure may be given. There are other plates capabte of recording truthfully a comparatively wide range of contrasts, though exposures may vary from 1 : 5 or 1 : 6, and, if troth- fulness of the intermediate tones be not absolutely demanded, such plates Are capable of yielding useful negatives within such ranges as 1 : 20 or 1 : 30. These different qualities of photographic plates are best represented ^aphically by the curve which we have termed the " characteristic carve " of the plate. The method of obtaining this curve will be presently described. Diagram No. 1 presents two characteristic curves of two well-known brands of plates wliich we will call A and B. We at once perceive a characteristic diflference between these two plates. While the carve belonging to plate A is nearly straight from exposure 0-(>25 <;m. to exposure 80 cm. , plate B yields a curve which has hardly any straight part in it. Now, we have shown that, if a plate must truly represent the contrasts of the subject, it can only do so if it possesses a perfectly straight portion within its characteristic curve. The longer this straight part is, the greater is the latitude of exposure for that plate. Plate A woald represent a subject with contrasts varying from 1 : 20 «with a high degree of truth, though the exposures varied from 0-625 : 4, from 1:6. If several exposures were made upon several plates, the •exposures ranging from 1 : 6, they would yield negatives of very difierent appearance, giving, however, identical prints, though the negatives were all simultaneously developed in the same dish for the same length of time. But, though all these negatives yielded identical prints, the pro- fessional photographer would discard them all but one, which to him, at all events, would be the only really good negative. There is one exposure, ^lnd only one, which yields a true representation with minimum density. Plate B, on the other hand, would never give a correct representation of any subject. Such plates could not be sold or used if the eye were <:apable of readily detecting photographic untruth in prints. It is owing to this defect that such a plate can be used at all. But the unsatis- factory nature of the plate, as revealed by the characteristic curve, makes •itself evident in practice by the very limited range of exposures which •will yield satisfactory negatives. With such plates Professor Burton -would have tried his art of altering density ratios in vain. Next in importance to the quality of the plate is the question of range ■of light intensities, which have to be recorded truly. Plate A is capable of representing light intensities lying between 1 and 70. If intensities bad to be photographed embracing a greater limit than 1 : 70, it could only be done by sacrificing truth or proportionality to truth altogether. In the case of plate B, the limit would lie between 1 and 2. The ques- tion arises, What are the usual variations in light intensities which have to be considered in photographic practice ? Many photographers appear to have highly exaggerated ideas upon this subject. We do not exactly know what Professor Burton's opinion is ; but it would appear, from his remarks, that the power of altering density ratios by variations in the developers can only be exercised in the case of plates which have received light intensities varying from one to at least several hundreds. From this we are led to assume that he supposed that the two prints he has recently published represent light intensities varying from one to at least several hundreds. Now, it is an easy matter to a^icertain the limits of light intensitiex which have to be dealt with in any given subject, and the following is the outline of the method we adopt in «noh an investigation. We cut • plate into two parts. Upon one part we make a series of exposare* to the standard candles so as to determine the characteristic curve, the other part of the plate is exposed in the camera to the object of which it is desired to ascertain the range of light intensities. We give such an exposure as will produce a correct negative, but it is not necessary to hit this very accurately. The two parts of the plate are then developed together for the same length of time, and with the same developer, and the highest and lowest densities of the negative, and such others as are of interest are measured, as are also the densities resulting from the candle exposures. It will be evident that this graded plate, produced by exposure to the candle, serves as the scale wherewith to measure the light intensities actually at work in the camera, and which produced the densities of the negative. For such experiments it is, of course, desirable to select subjects which present sufficient areas of uniform density in the negative. A useful subject, because it comprises the entire range of tone which a paper print admits of rendering truly, is an ordinary folding screen, upon each of two folds of which are fixed a sheet of white card- board and a sheet of matt black paper. The screen is so placed that one fold is illuminated by directsun light, and the other by the diffused light of the sky, and so that the sky itself is included in the picture. This sub- ject gives us five densities on the resulting negative, namely : — Sky. White, illuminated by the sun. White, ,, „ diffused light. Black, „ „ the sun. Black, „ „ diffused light. The following are the details of such an experiment, and diagram No. 2 illustrates graphically the method of ascertaining the equivalent of the light intensities in candle-meter seconds. A plate was cut into four parts ; three of them were exposed in the camera to a subject as just de- scribed, and the fourth was exposed to the standard candle, the exposures ranging from 0-312 cm. to 160 cm. The three exposures given in the camera were 08, 4, and 24 seconds respectively, and all four plates were developed together in one dish for the same length of time. The densities of the negatives and of the graded plate were found to be — Densities of Negatives. ExpoBnre. 0 8" 4" 2*" Sky Wiaite in sunlight White in shade Black in sunlight Black in shade 0-940 0-940 0-620 0120 0060 1-695 1-735 1-360 0-530 0-320 2-260 2-280 2-080 1-290 1-025 Densities op Gradep Plate. Eiposnre. cm. Density. Exposure, cm. Density. 0-312 0-625 1-25 2-5 5-0 0-150 0-275 0-440 0-700 1-040 1 10 20 40 80 160 1-360 1-665 1-935 2-160 2-295 The densities of the gradations obtained by these ten exposures were plotted as a curve, the logarithms of the exposures as abscisses, and the densities as ordinates. Parallels corresponding to the densities of the three negatives were then drawn, and where they intersect the charac- teristic curve perpendiculars were drawn through the points of inter- section. These perpendiculars indicate at one the equivalent exposures in centimetres which produced the corresponding densities. In diagram No. 2 the densities of the negative which received an exposure of four seconds are thus plotted, and it will be seen that the respective equivalent exposures are — !Sky 20-80 cm. White in sun 22-50 „ shade 1020 „ Black in sun 1-62 „ Black in shade 077 „ a 458 THE BRITISH JOURNAL OF PHOTOGRAPHY. [July 21, 1893 It ?riU thus be aeen that the whole range of light intensities, from matt black in the shade to the sky or white cardboard illuminated by the sun, is as 0^77 : 22-5, or as 1 : 29. Similar results were obtained with the other two negatives, and the following table gives their equivalents, the highest light being put = 30. RelatiTe intensities of light As shown by neg:atives exposed. emitted by 0^8". 4". 24". Sky White in sun 30 30 15 1-83 1-16 27-7 30 13-6 2 1 102 29 30 13 0 1^78 1-01 28-9 30 „ shade Black in sun 13-8 190 „ shade 1^06 We learn from this experiment that an object illuminated by direct sunlight is about twice as bright as the same object in the shade ; and that the whole range between a matt black object in the shade and a briMiantly illuminated sky is about as 1 : 30. It will also be aeen that the exposures given in the camera vary as 1 : 30, and yet the same rela- tion as to light intensities is revealed by the shortest, as by the longest, exposure. If we now examine Professor Burton's statements in the light of this, to him, evidently new knowledge, we have to point out that, according to his own confession, he cannot alter density ratios between limits of ex- posures 1 : 10 ; and he would not, we presume, undertake to seriously alter density ratios between such narrow limits as 1 : 30, since he says that " it is necessary to have ranges of exposures of at least several hundreds to one to be able readily to vary the density ratios." Now, assuming certain conditions, actiially never present in photographic practice, it seems, according to Professor Burton, true that it is possible to vary density ratios when the exposures vary between at least several hundred to one. Such variations do not occur in ordinary subjects ; the light intensities vary between limits of 30 : 1 at most. Professor Burton's faculty of producing negatives which yield similar prints is not due to his mode of development ; it lies wholly in the latitude of the plate and in the narrowness of the range of light intensities in his subject. He could have obtained identically the same result, and possibly a better, by means of one developer, and by simply varying the time of development for the shortest exposures. Two negatives are alike in their printing quality when the density differences are alike throughout, whatever the density ratios may be. Two negatives may have totally different density ratios, and yet be equally true to nature and yield identical prints, whatever printing pro- cess may be employed, so long as it is the same in both eases. Thus, so long as the light intensities of a given subject lie within a certain limited range, and the time of exposure is such that the densities produced fall within the straight part of the characteristic curve, so long will the density differences for the same subject be independent of exposure, and alike. Suppose the length of the straight part of the curve cover a range of exposures 1 : E ; and the light intensities to be photographed lie between ■p the limits 1 : 1, the latitude of the exposure would then be 1 : -v ; and within these two Umits any exposure wocld prodiuoe negatives which,, developed in the same developer for the same length of time, would yield negatives giving identical prints. Take the case of plate A. The straight part of its characteristic curve may be taken as extending from exposure 1 cm. to exposure 80 cm., i.e., 1 : 80. If a subject had to be photo- graphed which was illuminated by diffused light only, and in which the light intensities varied from matt black to white or even more, say a range of 1 : 20, the plate would yield negatives, with exposures varying from 1 : 4, almost identical in printing quality, though' they were all developed together. If a little deviation from truth is permissible, and the portion of the characteristic curve lying between exposures 0-312 cm. and 160 cm. (a range of 1 : 512) be considered as sufficiently accurate, the same subject would permit a latitude of exposure of \V = 25, and there would still be very little differences in the negatives, particularly if development be prolonged in this case of the shorter exposures. For a sunlit landscape the latitude would be %\^ = 17. The experiment we have described was made on a plate, the straight part of which only extended from an exposure of about 1^5 cm. to one of 50 cm. For an ordinary sunlit landscape its latitude of exposure is, 50 therefore, small, namely, r^—5jr = 1-1; and consequently, if a correct negative be required on such a plate, the latitude of exposure would have to Ue within ten par cent, of its own value. The negative which was exposed for four seconds is the truest of the three ; the one which received one-fifth of this exposure renders the high lights correctly, but not the shadows ; and the one which received six times the exposure of the first- named negative renders the gradations as far as white in diffuse light correctly, but not the highest lights. The following table shows the density differences for the various parts of the negatives, which would have to be all alike if the negatives must yield identical prints ;— Exposure ... 0-8" 4" 24" Density of clearest spot ... -060 •320 1^025 Density difference — Black in shade and black -060 -500 •320 •880 •21ft •830 •375 1-415 •265- „ „ Black in sun and white in shade •790i _j „ White in shade and white •200' Total range of negative— Black in shade and white in sun 1^255. It will be seen that the negative which received four seconds, the correct exposure, gives for all parts of the subject, with the exception of the highest lights, practically the same density differences as the one which received twenty-four seconds' exposure. In prints from these two nega- tives all gradations lying between black in shade and white in shade would be exactly alike, though the exposure was, in the case of one negative, six times as much as in the other. The negative which received' one-fifth the correct exposure only renders the high lights with equal truth. If, however, this negative had been developed for a longer time than the other two, its range could have been considerably improved ; the ratios remaining the same, the density differences would have altered,, and it could easily have been brought to the following :— Exposure 0^8" 4" 24" Density of clearest spots •100 •320 1 1^025 i Density difference— Black in shade and black in sun ... ^_ „ Black in sun and white in shade ... White in shade and white in sun ... Total range of negative— Black in shade and white in sun •100 •830 •.530 1^460 ■210 -830 •375 1^415 ■265 •79o -2Qo. 1-255 In this case the resulting prints would have differed little from each, other, since all the main gradations lying between black in shade and white in shade would have been represented by the differences -. — 0-8" 0^930 1-040 2i" 1-055 which are so nearly alike that the eye could not detect the difference:. July 21, 1893] THE BRITISH JOURNAL OF PHOTOGRAPHY. 460 Only in the highest lights, beyond white in shade, would the difference be at all apparent. The three negatives differ, however, very materially in the time they require to yield prints of equal depth in the shadows. The last of the series (twenty-four seconds exposure) requires six times, and the second (correct exposure) nearly twice (J the time which is needed for the first to print to the same depth.) From these experiments it is clear that latitude in exposure is not inherent in modifications of the developer, but in the plate itself, and in the comparatively narrow range of intensities which are ordinarily met with, combined with the inability of the eye to judge of the more or less truthful rendering of the various gradations. As already pointed out, among the many negatives which may be pro- duced by mere variations in exposure, there is only one which combines truthful rendering of tone with minimum density ; and it is this onn which the practical photographer aims to secure. For the more accurate and certain production of this particular negative, it is necessary to ascertain the speed of the plate with tolerable accuracy ; and we now propose to give a short practical description of the method we have adopted for this purpose. We believe that many amateur photographers would be glad to be in a position to determine speeds for themselves, and to obtain that knowledge of the properties of their plates which can only be derived from a study of the characteristic curve. The course we pursued in our original investigations was to expose portions of the sar^e plate consecutively to the light of a standard candle, doubling each successive exposure as we proceeded, and we naturally adopted this course when we came to make our first determinations of speed. The errors to which we found the candle liable, however, when we had not the experience in its use which we have since gained, showed that much was to be desired in order to secure a constant ratio of illumination between the different exposures, and, in order to secure this, we adopted the plan of making our exposures which we are about to describe, and which we believe to be the most satisfactory. By this method the whole of the exposures are made simultaneously, so that any fluctuations taking place in the light of the candle proportionally affect all the exposures, and the determination is consequently more decisive and less liable to error than if fluctuations in the light were to take place during one or more of the individual exposures. Moreover, the possibility of error arising from the difficulty of accurately timing very short exposures is wholly eliminated. We will, in the first place, make a few remarks upon the standard candle as a unit of light. While we candidly admit that the candle is by no means an ideal standard, we must say that we are not at present aware of any satisfactory substitute. We adopted it, in the first instance, because it was ready to our hand, well known and recognised as a standard, and easily obtained. And we may perhaps be forgiven for entertaining a somewhat higher opinion of it than some of our friends, inasmuch as it was, at any rate, reliable enough to lead to the discoveries we have made. It is asserted that the amyl-acetate lamp is a better stan - dord than the candle, but the practical difficulties in its use are such that we can only say it has not proved itself so in our hands. Altogether, we know of nothing, as yet, better as a standard than the candle, and, if the suggestions for its use which we are about to make be adopted, we do not think it will lead to serious errors. Two determinations of the inertia of tliis same plate which we have just had occasion to moke, on two different evenings, differed only by 0-04 cm., a discrepancy of absolutely no practical moment. We have unquestionably found that the standard candles of different makers do vary, and for this reason we think it well to say that the candles we have used throughout our investigations were supplied by Messrs. Sugg & Co., Vincent Works, Westminster. The normal height of the flame of these candles, measured from the lowest point at which the wick blackens, is about forty-five millimetres. Our method of using the candle for the purpose of speed determination is as follows. We will assume that the candle we are about to use has been used before. We light it, and then, with scissors, snip off the hardened tip of the wick ; the flame of the candle will now be found to grow steadily in height, and as soon as the distance from the tip of the flame to the lowest point at which the wick blackens has reached forty- five millimetres the exposure may commence. The candle flame may now be relied upon to remain sufliciently constant for about ten minutes, and tliis is amply long for our purpose. If after this time, for any other purpose, the light is required, it will be well to again trim the wick, and start de novo. The height of the flame may be measured by a strip of cardboard, upon which two marks are made at a distance of forty-five millimetres apart. It is, of course, obvious that these experiments should be made in a room free from draught, and it is often a wise precaution to pitkce the candle in a tall box, open on one side and well blackened inside. We are strongly in favour of keeping the candle well in view during tho entire exposure, lo that, should any fluctuation in light take place, we may be aware of it. If the candle be used in the open room, all white or bright surfaces capable of reflecting light should be removed. If a plate be examined by placing it between the eye and the red lamp, it will be found that the opacity of the film falls off at the edges. The edges should, therefore, be scrupulously avoided, and the strip should be cut from the centre of the plate, or, at any rate, well away from the margin. The operation of cutting the plate should be conducted as quickly as possible, and as far away as possible from the red Ught, so as to avoid all fogging action of the Ught upon the plate. The width of the strip may conveniently be made about one inch. When the plate is securely placed in the dark sUde, the latter is placed in its position behind the disc. The distance from the candle to the place occupied by the plate is carefully adjusted, and the candle is lighted and trimmed. When the flame has reached the requisite height. tHe exposure may commence. The disc is caused to revolve, and, at a given moment, the slide protecting the plate is drawn, and the exposure continued for the requisite length of time. Now, as to the best range of exposures to decide upon in the case of a plate of the speed of which we know nothing, we should advise a series commencing with 80 cm. down to 0 312 cm. This range will be fonod to include as much of the characteristic curve of the majority of c<>m- morcial plates as is required for a speed determination. A little con- tideratioa of the revolving disc, however, will show that, in order to give 460 THE BRITISH JOUKNAL OF PHOTOGKAPHY. [July 21, IdW an actual maximum exposure of 80 cm., it wUl be necessary to continue the exposure for twice 80, or 160 seconds, the candle being placed at a distance of one metre from the plate. The reason of this is that the actual maximum exposure only proceeds during half the revolution of the disc, the light only reaching the plate during the passage across it of 180° out of the 360°. Though we prefer to work with the candle at a distance of one metre from the plate, it may be brought nearer to it if it be desired to curtail the exposure. At a distance of 0707 metre, the light of the candle is equal to 2 cm., and at a distance of half a metre it is equal to 4 cm. Having exposed the strip, we next proceed to develop it ; and here we must say a word or two upon the subject of the developer. We do this knowing perfectly well that we shall meet with considerable opposition ; but we, nevertheless, again assert that, for all ordinary photographic worli, there is no developer superior to ferrous oxalate. We prefer it because of the uniformity of the colour of the silver deposited by it, a point of very great importance when we come to the operations of printing and enlarging by developing processes, in which the exposure is arrived at by calculation : we prefer it because we never yet found a plate with which it disagreed, and this is more than can be said of other developers. It will also develop an old plate which may have been care- lessly laid by for years ; whUe, with another developer, it would be hopeless to obtain a passable result. We prefer ferrous oxalate because, of all developers, it is least liable to attack silver salts, which have not been acted upon by the light, and because it will not lend itself to the production of foggy messes. We do not wish for a moment to imply that other developers may not have their special uses ; on the contrary, for example, we have found rodinal of the greatest value in the case of certain plates, when dealing with extremely short-shutter exposures, and also in flash light work. However, to proceed with the operation of development. It is advisable that this operation be conducted at a fixed temperature, and we find 65° Fahr. the best to adopt, as it is easily obtainable both in summer and winter. The developer itself should be brought to this temperature, and maintained at it by placing the developing dish in a water bath of the same temperature. The constituents of the developer are intimately mixed by stirring, and, at the moment of pouring on to the plate, the time is noted. The dish should only be rocked for a few moments, in order to expel any air bubbles from the surface of the plate, and should then be covered up, so as to expose the plate no more to the red light than is absolutely necessary. Examination of the plate during develop- ment should be avoided as far as possible, as no red light whatever is safe in the case of even a fairly sensitive plate ; and we believe that too frequent exammation, prompted by curiosity or impatience, is to some extent responsible for alleged alterations in density ratios. About five or six minutes will, as a rule, be found the best length of time to continue development, in order to obtain that range of gradation most suitable for subaequent measurement. But, however long development may be continued, the time occupied should be carefully noted. The object of the fixed temperature, and the exact time a given plate takes to reach a certain development factor, is of the utmost importance, if we afterwards desire, upon a similar plate, to produce another negative having a different range of density gradations. After development, the strip is fixed and washed in the ordinary way, and, after wasliing, it is well to wipe the surface of the film gently with a plug of wetted cotton-wool. The plate may be treated with alum if de- sirable, and both the alum and fixing baths should be fresh and perfectly clean. As the films of some plates are liable to loosen from the glass when submitted to the heat of the lamp in the photometer, it is some- times well to soak the plates for a few moments in a weak solution of glycerine after washing and before drying. When the plate is dry — and this may be hastened by means of alcohol if desired — the back of it ihonld be thoroughly cleansed, and the film wiped with a silk handker- chief. It will now be found advantageous to define the dividing lines of the smaller densities with a pen and ink on the film. This will materially assist when we come to measure the plate, which operation may now be carried out. We do not here propose to enter into any description of our photometer and the method of using it ; this will be found in our original paper in the Journal of the Society of Chemical Industry. The nine different densities and the " fog strip " having been measured, and having deducted from each exposure density the density of the in- cipient fog of the plate and that due to the glass and film as given by the " fog strip," we proceed to plot the characteristic curve on one of the skeleton diagrams supplied for the purpose by Messrs. Marion & Co. Assuming that our actual maximum exposure was 80 cm., we mark on the ordinate corresponding with this exposure this density, minus fog, due to the 80 cm. exposures; and so on till we reach the ordinate corresponding with exposure 0-312 cm. Having thus plotted all the nine densities, we take a piece of black thread and stretch it along that part of the curve which practically forms a straight line, and which indicates the position and extent of the correct period. This enables us to decide upon the position of the straight line before we actually draw it on the diagram. We now draw the line, and continue it till it inter- sects the inertia scale at the bottom of the diagram. The point at which the intersection takes place gives the inertia of the plate, which is then converted into the speed by dividing it into the constant 34. For ex- ample, inertia 1 = speed 84. We may now join up to either end of the correct-period curves passing through the remaining points of the deter- mination. The curve at the upper end will represent a portion of the period of over-exposure, and that at the lower end of the period of under- exposure, the whole representing tlie most important features of the characteristic curve. The details just described will be better understood by a reference to diagram No. 1. We should here like to express the importance we attach to obtaining, in every speed determination, distinct evidence of all three periods. It is only by so doing that we can be quite certain as to the position of the correct period. It would be quite possible for the higher densities in a series of under-exposure gradations to be mistaken for a portion of the correct period in the case of a high development factor — in fact, we have known this mistake to be made when, had there been evidence of the three periods, mistake would have been rendered impossible. We generally have some idea whether the plate we are about to'examine is a rapid or a slow one, and after a little experience it is easy to decide upon that range of exposures which will most probably yield evidence of the three periods ; but should we, in the case of a plate, of the speed of which we have no idea whatever, find that the exposures we have chosen yield a series of densities which leave room for doubt as to the position of the correct period, it will be necessary to make another determination, a more suitable range of exposures being chosen. The first determination will indicate whether a longer or a shorter exposure be desirable. We must here call attention to a diiBculty which may possibly arise ; but its occurrence is fortunately so rare as to speak well for the perfection of the machinery used for coating the plates. If, on plotting the densities, they are found to lie irregularly, so as to preclude the possibility of drawing through them a regular curve, there is serious reason to suspect an unevenly coated plate. In such a case as this, the best thing to do is to cut another strip from the plate from which the first was taken, and running in the same direction of the plate as the first strip. The second strip should now be uniformly exposed to the candle and developed the exposure and development being so timed as to produce an easily measurable density of, say, 10. If the plate have been unevenly coated, the density of the second strip, when measured in different places, will be found to vary. As an example, we have been able to lay our hands upon the record of a case which occurred in our own experience. The irregular series of densities obtained in the first instance led us to make a second exposure as described, when we found that the density measured in different parts of the strip varied from 1-335 to 0-820. When we remember that this means that one part of the strip transmitted more than three times as much light as another, the serious nature of such a fault as inequality in the thickness of the film will be apparent. Reference has been made several times to the development factor. It is beyond the scope of this paper, however, to enter fully into this sub- ject ; but, as the numerical value of this factor is one of the data to be derived from every speed determination, we will state how it is graphically ascertained. From the point 100 on the inertia scale of the skeleton diagram, aline, parallel to the straight portion of the charasteristic curve, is projected till it intersects the development factor scale. The point of intersection gives the factor which expresses the extent to which the development of this psirticular plate was carried. It is best for the pur- pose of speed determination to aim at reaching a development factor of I'O, or a little more. It will be seen, on referring to diagram No. 1, that the development factors of the two plates A and B are 1-18 and 1'52 respectively. We believe we have now explained the method of making a speed determination in sufficient detail to enable an amateur to carry out the operation We trust, however, that any amateurs who take the matter up will not content themselves with plotting the characteristic curve of a plate for the sole purpose of ascertaining its speed, but will take an interest in tracing, in the conformation of the curve, the results which they obtain in their photographic practice. It is a knowledge of this curve alone which can give the photographer complete control of the materials July 21, 1803] the: BRITISH JOURNAL OF PHOTOORAPHy. 461 he employs. On some other occasion we hope to show more fully than heretofore the part which the characteristic curve plays in the calculation of the exposure for transparencies and printing processes generally, as also in the production of negatives and positives having a special range of gradation. ON THE POWER OF COMPENSATING IN DEVELOPMENT FOR VARIATION IN EXPOSURE. By W. K. Borton. The experiments I am ahont to describe were certainly suggested by opinions expressed by, or at any rate commonly attributed to. Dr. F. Harter and Mr. V. C. Driffield some three years or so ago, but I wish to make it amply plain that I do not intend this paper to be taken as a refutation of any opinion that they hold — at the present time at any rate. In the first place, I admire so much the method of investigation that these gentlemen have pursued, that I should be very sorry to write any- thing that might tend to lower the estimation in which these investiga- tions are held, even if, as may be the case, the conclusions arrived at are not exactly in accordance with fact ; and in the second place, because, if there is any refutation to be done, there are plenty of people on the spot much more able to undertake it than I am. As far as I have followed them, Messrs. Hnrter & Driffield at first stated that it was impossible, by development, to alter either the density or the opacity ratios in a negative. In other words, that were the thing represented graphically, with light as abscissae, and one of them having density and the other having opacity as ordinates, then, the abscissae remaining constant, the ordinates might be altered by variation in the developer, but that their ratio to each other could not be altered. It is, however, as a matter of fact, very easy to so alter the ratio by variation in development that two curves, representing either density or opacity, would intersect each other, in which case the ordinates would, of course, not be proportionate. I understand, however, that Messrs. Hurler & Driffield have considerably modified their views since their first statement was made, and it may be that I do not here represent fairly even the first position that they took up. Be all this as it may, it is undoubtedly the fact that, some year or two ago, it was the general impression that it had gone out on high authority — with a sound of trumpets almost — that it was impossible to compensate for variation in exposure at the time of development, and that with the same exposure it was impossible to control in any way the result, except in so far as density was concerned. Now, I hope to be able to demonstrate that we have power, by variation in development, to compensate for enormous differences in exposure, and that with the same exposure we have enormous control over the results. The experiments that are to be described were begun some two years or so before the time that this paper is likely to be read, but were inter- rupted by work of one kind and another that seemed more important, the truth being that I felt no great enthusiasm to prove a thing that was a matter of every-day experience. It was like proving, by the aid of a shokojimeter, that if you got no dinner you were likely to be hungry, if you had enough to eat your appetite would be appeased. When I got thoroughly into the experiments, however, I found them of the greatest interest, because I began to find that our power of compen- sation is even greater than I had ever supposed, and I found it possible to work out at least an approximate rule for the variation in development that had to be made for a given variation in exposure. I wish to state my very strong opinion that experiments on gradations of density (or of opacity) are not of any real value, as throwing light on the probable result of exposure in the camera, unless they include such a range of gradation as is commonly met with in actual camera work. I find this range to be generally, at least in ordinary cases, as several hundreds to one, often as a thousand to one, and sometimes as several thousands to one. What I mean is, that the plate has received at the time of exposure several hundred, or a thousand, or several thousand, times as much light at one point as it has at another. In this connexion it is to be noted that the range of light reflected by the object photographed is always greater than the range of light that reaches the plate ; that it is often much greater. Thus it is practically possible to have the nearest possible approach to absolute black in the object photographed, otherwise an approach to zero of light, in which <:a8e the range approaches infinity. In the case of the light actually reaching the plate this cannot be the case, on account of the unavoidable (liffused light in the camera. For the preliminary experiments a sensitometer on the principle d that of Messrs. Mucklow & Spurge was made. The areaa of the apertures varied in the ratio of 1, 2, 4, 8, 16, 32, CA, 128, 256, 612, 1024, and 2048. The holes were bored by a watchmaker, the largest being one inch in diameter, and, as far as I can make out, the diameteri are very nearly what they ought to be. The instrument it a convenient one, using quarter-plates, and many experiments were made with it. It was, how- ever, considered that these could not be taken as conclusive, becanae plates could be exposed only in succession, and no standard light was available. Moreover, it was found that a gradation varying from 1 to 2048 was not sufficient for a thorough investigation of the subject. It was, therefore, decided to construct a sensitometer in which plates could be directly exposed to hght, each half having the same exposure. The plates were then to be cut in two, and the two halves were to be developed in any two developers, the effects of which it was desirable to compare. This sensitometer is shown in the two photographs, L and II. It is of very simple construction. Photograph II. shows a back view of the sensitometer. It has a door A, which is shown open. Through this door a plate 12 x 2} (one quarter of a 12 x 10 plate), B can be introduced. The plate is held in a brass frame or carrier, D, that can be raised or lowered by the bar E, having a toothed or serrated edge. This bar is pressed by a spring in the direction of these teeth so that it will remain at any ol fourteen different heights, holding, of course, the plate vrith it. The spring, F, presses the film side of the plate very nearly into contact with the front of the sensitometer. In fig. 1 will be seen a slit, G, two inches in length and a quarter inch wide. This slit is covered by the flap, H, unless the same is held open by hand, as seen in the photograph. The apparatus is designed to give exposures to different transverse strips of the plate of the size of the slit, G, in the'ratios of 1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096, and 8192. Many of the results of experi- ments will show that this range is not at all too long for investigating the effects of different developers on the two halves of the same plate, though the range is far greater than can be registered correctly. With any plate so exposed and developed, the strip having the shortest exposure is visible. It was found by experiment that the shortest exposure that could be given with the flap varied very little, and was nearly exactly one-quarter second. A half-second could be guessed with some approach to correct- ness, one second with more, and two seconds could be measured roughly with a stop watch, four seconds with but a small percentage of error — all this after some practice, of course. It was, therefore, decided to make the exposures begin with a quarter- second, and work up doubling. It needs, however, only a very little arithmetic to discover that, even beginning at this short length of time, the last exposure must be con- siderably over half an hour, and to make hundreds of exposures of plates, in which the last item alone came to more than half an hour, was not to be thought of. For this reason the first exposures were all made a quarter-second each, but the distance of the plate at the time of the first exposure, 10 feet, was made 7 feet for the second, 5 feet for the third, 3 feet 6 inches for the fourth, 2 feet 6 inches for the fifth, and 1 foot 9 inches for the sixth and all others. These distances vary very nearly as 1. fJh, sJi, s/h< s/i\, and Js\. That is to say, the quantity of light was doubled at each approach of the sensitometer to the source of illumination, all the exposures at 1 foot 9 inches from the light needed only Jj of the time they would have needed at 10 feet, and the longest exposure was reduced to 64 seconds. It is not pretended that the successions were really actually those mentioned above, and it is of no consequence that they should be. Whatever irregularity there might be was bound to effect one half of the plate exactly as the other ; and, as the after-process consisted in cutting the plate in half longitudinally, and developing the two halves in different developers, the only thing essential is that the two halves of the plate should have exactly the same exposures. Nevertheless, I venture to state that the exposures of all those strips that were exposed at different distances gave very nearly the ratios mentioned, as the rapidest possible opening of the flap was found to remain very uniform, and a dead black screen was placed behind the light to prevent reflection, which would considerably modify the law of the quantity of light varying inversely as the square of the distance, at any rate considering our light as the centre of illumination. The ex- posures i and 1 second are, of course, the most uncertain. From two seconds on, it may be considered that the acceleration is that stated within very narrow limits of error. In no case did the light vary more than about ten per cent, during the making of one set of exposures. The result of one set of exposures might thus be roughly compared with eaefa 462 THE BRITISH JOURNAL OF PHOTOGRAPHY. [July 21, 1893 other, even comparing different slipa, but the necessity for this has been avoided by always developing together, in a developer that will be stated, one half of each slip, so that any difference in exposure can be I have signed my name across each slip, before it was cut in two, that there should be no mixing up, and lest any should doubt the genuineness of the results. These plates would form a condrmation, were any needed, of the recent statement by an expert in handwriting, that no one can sign his name exactly the same twice, and that, if two supposititious sig- natures that exactly superpose each other are discovered, it may be concluded that one is a forgery. To return to the plates, however, as the vendors of various sauces and other goods remark, " Without this signature none is genuine." As a light an oil lamp was used. I have found a common oil lamp, with burner in good condition, well trimmed, with a fairly large reservoir, and with a good quality of mineral oil, to be much more constant for several hours than any candle that I have been able to find, if it is first allowed to burn till all parts that heat have become hot. Of course it is not so good for making comparisons on different days, because the light of a lamp is very liable to vary from day to day. I wish, however, here to remind you again that the results of my experiments are in no way dependent on either the intensity or the uniformity of the light. It was found that, using a well-known brand of commercial plate, sold ai " ordinary," a small lamp of five to six candle power was just capable of giving a developable image with an exposure of one quarter of a second at a distance of ten feet. I have certainly at times worked exceptionally rapid plates that needed only one-fifth to a sixth of the exposures of these. We may, therefore, deduce the fact — by no means bearing on these experiments, but of some interest — that the most sensitive plates made will be visibly affected by an exposure of a mere fraction of a second at ten feet from a candle. The greater number of the exposures were made with such a lamp as this ; but, in some cases, where it was considered advisable that the first figure in the sensitometer, in the sense of the first exposed, should develop ont quite markedly, the exposure was made to a lamp with a burner giving a nearly spherical flame (called, I think, a " rose burner ") having a power of some twenty to twenty-five candles. Where numbers of strips exposed are stated, it is to be understood that No. 1 is the strip that was first exposed, and that had the shortest ex- posure. The "first four strips," or Nos. 1, 2, 3, and 4 means, for example, these strips that received each quarter-second exposure at distances of ten feet, seven feet, five feet, and three feet six inches from the lamp. I wish to state here that nearly all development was done by my assistant, Mr. K. Arito, from written instructions given to him by me. without comment. I had distinct reasons for this. In the first place Mr. Arito is a very careful operator, much more careful than I am — though that may not be saying much. In the second place, although, o^ course, he knew the general drift of the experiments, he knew nothing Oj what had given rise to them, or of the exact lines that I was working on He was, therefore, much less liable to be carried into the inaccuracies that I distinctly state most of us are liable to be carried into un- consciously, or nearly so, when we wish experimentally to prove a particular fact. Still farther, it enabled me to make sure that the experiments could be repeated by any intelligent operator from briefly written descriptions. Wherever " normal pyro and soda" developer is referred to, it is to be taken as referring to the developer that the writer has most commonly need for several years past, that is to say, one compounded as follows : — To each ounce of developer — Pyro (either dry or freshly mixed, without pre- servative) 2 grains. Sodium carbonate (crystalline) 12 „ Sulphite of soda 12 „ This generally works without fogging, but sometimes, not always. When a new batch of plates is bought, a sample is tried, and the quantity of bromide needed to prevent any hurtful amount of fog is determined This never exceeds half a grain to the ounce of bromide of potassium with any plate that would generally be pronounced workable. In all these experiments a quarter of a grain of bromide of potassium was used to each ounce of " standard pyro and soda developer." I do not wish to reopen the old discussion as to ammonia against other alkalies for development with pyro, but shall merely say that I have, for some time, considered that it was possible to get more out of a short exposure with soda, considering not detail only, but the whole of the negative, than with ammonia, and that the present experiments confirm this ; that, moreover, I thought till recently that there was greater latitude of exposure with soda than with ammonia, but that these experiments have made me change my mind in this respect, as I have been able to get greater latitude with ammonia than with any other alkali that I have tried. Here it may be mentioned that a set of experiments incidental to the main experiments was made to discover the relative quantities of bromide of potassium and of bromide of ammonium that were necessary to h^ve the same retarding effect. It was found that, for unit quantity of bromide of ammonium, it was necessary to use that quantity multiplied by between IJ and 2 of bromide of potassium. Probably, the exact multiplier lies very nearly half way between these two — perhaps 1-875. It is near enough for all practical purposes to state that it takes nearly twice as much bromide of potassium to do the same restraining work as any given quantity of bromide of ammonium. It will be seen that the difference is much greater than the different weights of actual bromide contained in the same weights of bromide of ammonium and bromide of potassium. After a somewhat random set of experiments, conducted to decide on the best line? to work on, more systematic experiments were undertaken^ I here give the results of the most interesting of these, not by any means necessarily in the order in which they were carried out. In all cases the temperature of the developer was kept at as nearly 65° Fahr. A. The instructions were : — " All plates to be developed with a developer containing two grains pyro, twelve grains carbonate of soda, and twelve grains sulphite o soda." " One-half of each plate, to be marked 'A,' to be developed withoat bromide, till the last figure is distinctly visible, till there is fair density, but development to be stopped before there is distinct fog." " No. 1. Develop the B half with a developer containing one-half grain of bromide of ammonium per ounce, but stop when strip 2 only is of the same density as strip 1 in the A half." " No. 3. One grain of bromide of ammonium to the ounce, stop- development when No. i only is of the same density as No. 1 in the B- half." " No. 6. Eight grains of bromide of ammonium to the ounce, stop development when No. 7 only is of the same density as No. 1 in the A. half." There were intermediate numbers, and also numbers np to and inolnding No. 8. I select, however, and send you the results of these three only, as being typical. These were exposed to the large lamp, and the results must be taken as illustrating those of over-exposure. In the case of all other results sent, exposures were to the small lamp. It will be seen that, in the case of No. 1, the density of the first few strips is, to all intents and purposes, the same in A and B, but that the density rises, after a little, more rapidly in B than in A. Farther than this, tlie opacity reaches a maximum at about the ninth or tenth strip in the case of the half A, whereas it keeps increasing till nearly the end of strip B. At the end the opacity of B is much greater than that of A at any part. It will be seen that the compensation for over-exposure here has been considerable, and that the curves, both of density and of opacity, cross each other, so that the density ratios are changed. In No. 3 the same thing is to be remarked, and, besides that, the first strip or two of B are less opaque than the corresponding strips of A. Here there is greater compensation for over-exposure, and the curves of both density and of opacity cross each other, so that the density ratios are changed. In No. 6 the same thing is to be noticed, with the complete suppression of the first four, and nearly the complete suppression of the next two strips of the B side. It must, however, be explained here that intensifi- cation was resorted to. The reason for this was that, with the large quantity of bromide here mentioned, corresponding, say, to fifteen grains of bromide of potassium to the ounce, the image was white by transmitted light. I mean the deposit. It had no printing value at all, and I had not time to discover even if it was of silver. At any rate, it blackened, or rather browned, under intensification. It will be seen here that, at any rate, the curves of opacity cross, and that the opacity ratios are very much changed. This is, however, by the use of an intensifier. The next plate, with double the quantity of bromide in the developer, showed the same peculiarities even more strongly than the last, and it was found im- possible even to " brown " the image. July 21, 1893] THE BRITISH JOURNAL OF PflOTOORAPHY, 468^ A great number ot expertmenta here intervened, having for their object the invcHtigntion of the effects of varying the quantity of pyro as well as that of the restraining bromide, and also to discover to what extent com- pensation tor variation in development can be carried by combined varia- tion in the developer with the after-application in the intensifiers. The results of all these experiments being summed up in those got with ammonia as an alkali (the experiments just referred to were all carried on with carbonate of soda), I therefore prefer to leave them out, as the recounting of them would be tedious, the more especially as I found the results, in the matter of compensation for variation in exposure, much better in the case of ammonia than with soda, in great measure on account of the whiteness of the deposit with soda, when much bromide was used, that has been already mentioned. A set of experiments was now made to compare what I have called the " normal pyro and soda developer," in its results, with those of pyro and various proportions of bromide and ammonia. As I have said, I came to the conclusion that, vary the ammonia developer as I would, I could not get out as much witli it as with soda without fog, and it is to be observed that the advent of fog is the limiting line of the action of any developer. The developer that is the most powerful reducer is not by any means of necessity the most efficient developer. It is that developer that can differentiate the most between bromide of silver that has, and that has not, been affected by light that is the most efficient. B. This series of experiments is intended to show the power of varying the effects of a uniform exposure, in a manner that would correspond to compensating for variations in exposure, with the ammonia developer, varying the quantities of each of the three constituents, and intensifying in certain cases. I think these experiments are conclusive as to the enormous control that we have over ouc results by variation in develop- ment. The instructions wore : — " Develop aU halves A with a developer containing half a grain of pyro, half a grain of bromide of ammonium, and two and a half minims of ammonia to each ounce. Develop either till slight fog shows itself or till all action has, for some time, ceased." " Develop all halves B with a developer containing four grains of pyro, [four grains of bromide of ammonium, and four minims of ammonia to [each ounce." (It is to be observed that these quantities had been determined on from [the results of previous experiments. ) " No. 168B, restrain one figure (i.e., stop development when the density t No. 2B is the same as that of No. lA)." " No. 169B, restrain two figures {i.e. , stop development when the density ' No. 3B is the same as No. lA)." "Noa. 170, 171, and 172B, restrain three figures." " Nob. 173, 174, and 175B, restrain four figures." " Nos. 176, 177, and 178B, restrain five figures." " Nos. 179, 180, and 181B, restrain six figures.", " Nos. 182, 183, and 184B, restrain seven figures." "Intensify Nos. 171, 174, 177, 180, and 183 with bichloride of mercury KoUowed with ammonia." " Intensify Nos. 172, 175, 178, 181, and 184 with bichloride of mercury, ollowed by sulphite of soda." Prints from the whole of this series are sent. It should be remarked bat, in making all prints from these long sensitometer-exposed plates, he effect of fog is, so far as possible, eliminated where it is present, by hading the unfogged half of the plate during development, so that the DOst transparent part of each half is, as nearly as possible, represented ' the same tint. It will be seen that, except in the case of No. 182, the curves of opacity Bore or less distinctly cross. Tlie meaning of this, in the particular ase referred to, is that, whereas the first strips of the A halves show ater opacity (and consequently print lighter) than the corresponding rips of the B halves, the last strips of the A halves show less opacity land consequently print darker) than the corresponding strips of the B halves. In many cases the first strips of the B halves are not visible at all, whilst they are even printable in the A halves ; nevertheless, the opacity of the last strips of the A halves is greater than that of the B halves. It will be evident that, even in the case of No. 182, the curves of opacity would cross were the gradation of light longer. On account, however, of the fact that seven strips have been restrained in the case of B, the gradation of light capable of giving a developable result is only 1 to 128 in B, as compared with 1 to 8192 in the case of A. Certain irregularities will be readily noticeable in these results. They arise from the difficulty in following exactly laoh instmotions as ■• re- strain 4, 5, or 6 strips." On this account (he whole system of compen- sation in development, for variation of exposure, and of varying the results with constant exposure, may be condemned by some. I shall only remind those who incline to do so that it is always a diffionlt matter in photography for even the most skilled to get the exact result they wish. I considered that the last set of experiments described indicated powers to compensate, in development, for exposures varying as one to con- siderably more than 100 without resort to intensification, as one to several hundreds having resort to intensification, hence experiments to be described presently. C. These experiments were undertaken as introductory to a set of experi- ments witli the ferrous-oxalate developer. The instructions were as follows : — " Prepare a saturated solution of oxalate of potash, and another of ferrous sulphate (each at a temperature of 05° Fahr.), and make each acid enough, with sulphuric acid, to turn litmus paper quickly red." " Develop all A halves with normal pyro and soda developer." "Plate No. 17B, develop with one part iron solution to three parts oxalate solution." " Plate No. 18, one part iron solution to four of oxalate." " Plate No. 19, one part iron solution to six parts oxalate." "Plate No. 20, one part iron solution to ten parts oxalate." " All plates, both A and B, to be developed either till slight fog appears, or till all action seems to have ceased for some time." One result of these experiments is to show the very slight difference in the action of this developer, by variation in the ingredients, except in so- far as time of development is concerned. As the developer becomes more diluted, the opacity throughout is slightly increased ; but this is really because the fog point came comparatively earlier with the concen- trated than with the dilute developers, and in each case development with oxalate had to be stopped because the fog point was reached. Another thing it shows most strikingly is the inferiority of ferrous oxalate, at any rate without the addition of bromide, in the rendering of gradation. A print from plate No. 18 is sent to illustrate this. It will be seen that, in the half B, the greatest opacity is reached at about the eighth strip, after which reversal takes place, whereas in the case of the half A (pyro-developed) opacity increases nearly to the end of the line. Here both the opacity and the density curves cross, and the density ratios are not the same. D- " Develop all halves A with ' normal pyro and soda developer.'" " AU oxalate developers to be made up of one part of the iron solution already mentioned to four parts of oxalate of potash solution." " No. 87B to be developed with the above normal ferrous oxalate solu- tion, without bromide, till slight fog appears, or till all action appears to have ceased for some time." " No. 88B to be developed with ferrous-oxalate developer having one grain of bromide of potassium per ounce. " " No. 89B to be developed with ferrous-oxalate developer having two grains of bromide of potassium per ounce." " No. 90B to be developed with ferrous-oxalate developer having four grains of bromide of potassium per ounce." " No. 91B to be developed with ferrous-oxalate developer having eight grains of bromide of potassium per ounce." " No. 88B to have one strip restrained." " No. 89B to have two strips restrained." " No. 90B to have three strips restrained." " No. 91B to have four strips restrained." Prints are sent of the results of all these exposures. It will be seen i that, by stopping development before it is complete, in cases where bromide has been added, we have the power of compensation for varia- tion in developing, or of varying the results of constant development, as in the case of the pyrogallol developer, though I am not prepared to say that the curves of either opacity or density actually cross in the cases ander consideration. E. So far all experiments described have had for their object the alteration of the results with fixed exposure. The next experiments were intended - to investigate to what extent it was possible to get identical results witii varying exposures. It was decided to rely on exposures In the cameri for this, although some preliminary experiments were made with the.- sensitometer, using the long plates of glass. 464 THE BRITISH JOURNAL OF PHOTOGRAPHY. [July 21,1893 It was soon found possible to produce, with exposures varying as much as ten to one, or even twenty to one, negatives so nearly identical that ■they were both pronounced, by experienced photographers, good negatives, neither over nor under-exposed, and that, moreover, were of such a nature that these photographers would not undertake to state which of the two negatives had had the longer exposure. This was not enough, however. The experiments already described indicated the possibility of compensating for a variation of at least one to 100, and an attempt was made to systematically investigate the variation in the developer that was necessary to compensate for a given variation in exposure. In the first place exposures were made on a well-lighted landscape •varying in the ratios of 1, 2, 4, 8, 16, 32, 64, and 128, and attempts were^ made to discover the variation in the constituents of the developer that would give similar results with all these exposures. For various reasons it was decided to keep the quantity of alkali— for reasons already stated ammonia was preferred — constant, whilst the quantities of pyro and of bromide were varied. The first thing to do was to find the best relative quantities of pyro ammonia, and bromide for the production of a normal negative by a normal exposure. A normal negative I can only define as the kind of negative that an experienced photographer wishes to get. This, I con- sider, must remain a matter of opinion or even of taste. A negative with -opacities directly proportional to the light reflected by the different parts ■of the subject would be a perfect negative (apart from the rendering of ■colour values) if all printing processes were such that different parts of prints made by them reflected quantities of light proportionate to the ■opacity of the negative. This is not, so far as I know, the case for any printing process through any great range, and is far from being so in the ■case of many of them. There is a still farther objection to the above definition of a perfect negative, namely, that no plate that is made has the power of producing such a negative with ranges of light nearly as great as are common in landscape work. We must of necessity make up our minds to sacrifice something either of the shadows or of the high lights, and it is purely a matter of taste which we prefer to sacrifice. A close examination of the photographic pictures recently sent from the Camera Club to Japan, for -exhibition in the latter place, and representative of the most artistic work done in the Occident, seems to show me that workers of the most advanced school tend to turn out work that would have been spoken of as ■" under-exposed" some few years ago. That is to say, they see fit to abandon that so-called " golden rule " — in any way supremely idiotic — ■" take care of the shadows and let the high lights take care of themselves,' and often, at least, prefer to sacrifice something in the shadows for the '.sake of the high lights. Normal exposure I shall define as the shortest exposure that will give the negative that the photographer wants to get. Normal developer might perhaps be defined as the best developer for producing this normal negative with normal exposure, but it looks rather like giving definitions in a circle. Let me state here, parenthetically, that the prints you are to see just now are not by any means from negatives of the kind that I like to get. The negatives are altogether too hard. This was because I assumed that ^be developer that was " normal " for certain quarter-plates that I had >been using would also be normal for 12 x 10 plates of the same brand, but A different number. This was not so, however. Of course I ought to have repeated the experiments, but I had already exposed over a gross of 12 X 10 plates, besides innumerable quarter-platea, and the time was getting short for putting my material in form, so I let the negatives slide as illustrating my point quite well enough. To return, however, to the plates exposed in the ratios mentioned above, the ammonia was kept constant, and various multipliers of bromide and ammonia were tried for each doubling of the exposure. My first impression was that the bromide ought to be increased in a rapider ratio than the pyro, but this seemed to be a mistake. It appeared 'that better results — that is to say more uniform— were to be got by increasing the pyro and the bromide in the same ratios. At first I tried using half as much again more pyro and bromide for ■each doubling of the exposure, that is to say, multiplying the quantity ■of pyro and of bromide each by f for each doubling of the exposure. It was found that with this increase of the quantities of chemicals mentioned rthe contrast increased greatly with the increased exposures, and the negatives from those that had had the longest exposures appeared actually >nnder-exposed as compared with those that had had the shorter exposures. Next was tried using one -third as much again more pyro and bromide for each doubling of the exposure, that is to say. multiplying by |. The result was the same as in the last case, but to a less marked degree. This entirely knocked on the head a theory I had formed that the proper multiplier was probably ^2. Next was tried using one-fourth again more pyro and bromide for each doubling of the exposure, that is to say, multiplying f . It was found that tliis multiplier was somewhat too small. That is to say, the nega- tives that had had the longest exposures were thinner than those that had had the shorter. The falling oft in density was not, however, perceptible through the first five negatives. It is evident that the proper multipliers, if a constant multiplier is what is correct, and it is evident that such is very nearly being the case, must lie somewhere between J and J, or IJ and IJ ; between, that is, 1'2 and 1-25. Let us say it is 1-3, the thing might be put in the form of an equation, as follows : — Let C = quantity of pyro (or of bromide) used for right exposure. Then, if exposure = 1 Pyro = C = 2 •,, = C X 123 r, „ = 4 „ = C X (l-23)» „ = 8 „ = C X (1 23)3 „ = 16 ■... „ = C X (1-23)* „ = 32 , = C X (l-23)» . r„ „ = B „ = C X (l-23)» ■ ■ I When 2n = E Therefore, n = ;=|^f logJE .-. Pyro = C(l-23)i»K.a 1 Then, since (1-23) '"s- ^ = 2 Finally, pyro = C x (2)1''8-e From which equation a curve, or a table, might be made for practical use. • This law is, at least, approximately true for several brands of plates, for sundry initial variations of developers, at least, within limits of the normal exposure, and this multiplied by 100 or so. Your attention is now asked for a set of prints from negatives that have had exposures varying as 1, 2, 4, 8, 16, 32, 64, and 128, the same brand of plate being used, and the exposures being made about mid-day — as a matter of fact, from a litUe before till a little after, as quickly one after another as was possible, the weather brilliantly clear. I should like to know if any one, seeing these prints, will undertake to place them in the order of their exposures. I cannot myself. I cannot, in their present form, even tell which is the first and which the last. They are, however, cut from 12 x 10 prints, and it was pointed out to me by a very " cute " friend — he ia from the United States of America— that it was possible, in the original condition of the prints, to tell the two that had had the longest exposures, on account of the effect of the motion of the overhanging branches of a tree that gave a little beauty to the other- wise very uninteresting little bit of landscape — uninteresting, unless it may interest some old friend to know that the vehicle in the foreground (put there to get a bit of really dark shadow, to help the judgment in development) is that in which his humble servant is ignominiously trundled about the streets of Tokyo by a blue-coated, bare-legged oooUe ! I cannot tell the first six negatives one from the other by inspection, but the last two I can tell from the others, and from each other, on account, not only of the yellowness of the image, but on account also of a yellow deposit (I do not know what else to call it) in the shadows, or rather, all over the plate, including those parts of the plate protected by the rebate of the printing frames. This discolouration is one of the only two reasons that I know of why compensation for variation in exposure should not be indefinite. It makes the time taken for printing very long. I have, in experiments with quarter-plates, got results without this stain and objectionable colour of image, with exposures varying more than those mentioned, and thought, at one time, that I had got to the bottom of the matter. I find, however, that I have not. Its appearance is un- certain. Perhaps it is due to impurity in some one or more of my chemicals acting for a long time. I somewhat suspect the sulphite I am using. Another reason why compensation must be limited in practice is the outrageous length of time that development takes when the exposure is much above normal, and is compensated for by variation in the developer. The plate of the eight, from which the prints that are shown were made, that took the longest exposure, took two hours to develop. It may be urged that the prints are not identical ; it is quite true that they are not. I only point out that there is no uniform variation, and remind you how very diflicult it is to make even two really identical July 21, 1803] THE BUITISII JOUUNAL OF PHOTOORAI'IIY. 466 negntives (assnmini; that the conditions are such that it in possible), if ■only one factor varies, say, the rapidity of the plate. I should like to see any one malie eight identical Degatives on eight plates, varying in sensi- -tivenesB as 1 to 128 at the first attempt, and it must be borne in mind that this vas the first experiment made after I had concluded that tite formula given above represented approximately the variation in developer necessary, that the brand of plate used was somewhat dilTerent from any we had been using before, and that the only instructions Mr. Arito had were, " Use these developers for the different plates, and make eight negatives as like each other as you can." I am sure it would have been possible, by several trials, to get negatives practically identical.* As to the actual developers used, I must confess that to avoid the trouble of multiplying the quantity of pyro and of bromide by a much awkward fraction, 1-23, which I had not then arrived at, for each incre- ment in exposure, or of integrating from the initial quantities, by the use of a table of logarithms, I multiplied in the first three cases by four- thirds, in the last four by five-fourths, the result being not much different from what would be got working by the actual formula. The nearest quarter grain and, towards the end, the nearest half grain ■was taken in every case. The following were the actual developers used : — r L 16 32 64 128 Pyro, 3 grains, Bromide of ammonium, J grain, f Pyro, 4 grains. I Bromide ammonium, 1 grain, f Pyro, 5 grains. X Bromide ammonium, 1^ grains. I Pyro, 6 grains. ) Bromide ammonium, IJ grains, j Pyro, 8 grains. \ Bromide ammonium, 2 grains. !Pyro, 11 grains. Bromide ammonium, 2} grains. fPyro, 14 grains. Bromide ammoniam, 3^ grains. j Pyro, 19 grains, j Bromide ammonium, 5 grains. > B a o P to 3 a' i' The sulphite used was only five grains per ounce in the first six cases, ten in the last two. The reason the quantity was kept so low was that, with the long times of development necessary in the case of the longest •«xposure8, the plates were found to partly fix out before development was ■over if the sulphite were kept at four or five times the quantity of the pyro. I do not yet know whether this was due to impurity of the sulphite I -or not. The exposures actually given were as follows : — ins. Sees. 14 3 6 13 2i 48 1 36 3 12 They were made by myself, by the aid of a stop watch, with such care I Tis I am capable of. There may be an error of a fifth, or even perhaps a quarter of a second, in any one of them, but I think not of more. It is \ "true that this amounts to a considerable percentage in the case of the -shorter exposures ; but the error is as likely to be in one direction as in I the other, and, is any case, it leaves the range of exposures as one to fully I « hundred. In a sealed envelope, wliich I hope will not be opened till any who have { liad patience enough to listen to this paper as far as this point have tried I to put the prints in their proper order, are given numbers corresponding to letteis on the backs of the prints. It is to be understood that No. 1 orresponds with the shortest exposure, and so on. Conclusion. 1 hope I have proved by these experiments thai we have power both I to vary in development the results of uniform exposures, and to com- * The print marked ** 9 " on the back was from a neKative that had an exposure the j same as the longest of those mentioned, and that was developed with the first of the I •developers ^ven. It was removed from the developio}? dish ns sooa as marked fog I Mt in. Another plate was exposed for the same length of time, and was developed iu > the same developer, bnt was given the same time in the solution that hjid beea [ veoeesar; for the plate that bad an exposnre of one and a half seconds— namely, J fire minates. The resnlt is almost complete blackness, but with some reversal. If I ^here were a week to spare, and certainty of sunfbine all day long on everj day, I ^ «hoald make a print from this negative too. pcnsate for difTcrences of exposure. I should not have thought it right to trouble you with so long a paper on the matter, but that the possible variations, and the possible compensations, have proved so much greater than I imagined them to be, and so much greater thin they are, I think, commonly supimscd to be. It will be seen that throughout these resalts, in bo far as they consti- tute change in ratio of gradation, are brought about only by stopping development at certain stages before it has gone as far as it would go. I doubt if it is possible to change gradation of density or of capacity at all, if development be carried as far as it will go. At any rate, the change that can be effected is but slight. This is leaving out of the ({uestion the reaching of, or approaching to, a maximum possible density. When some twelve or thirteen years ago I stated that " bromides restrain both the increase of density, and the increase of detail, bat the former to a less degree than the latter," I believe I stated, in somewhat crude language, the reason why it is that bromides in the developer give us the power both of varying our results with constant exposures, or of compensating for varying exposures. Before that time, if I remember rightly, I had found, to my own surprise, that it was possible, if only time were given, to bring out the same figure on plates exposed under the Wamerke sensitometer, however great the quantity of the bromide added to the developer, within pretty wide limits. The results of these experiments were communicated to The British Journal of Photographv in one, or I think more than one, article that I have not access to here, and were, I remember, discussed at the rooms of the Society of Arts, probably before the South London Photographic Society. After that, a more elaborate set of experiments was made, investigating the results of varying each of the three ingredients of the alkaline developer, the results being communicated again to The British Journal OF Photoqraphv, aad the actual plates being handed to the Camera Club, after that institution had been founded. The results of these experiments are referred to by Mr. H. J. Channon, in a very interesting paper in the International Annual for 1891, p. 25.5. I also received much information from this gentleman, and various papers, all of which courtesy has, I fear, passed unacknowledged, for which omission I crave forgiveness. I have given the results of only a fraction of the experiments that intended to describe. These include the comparisons of the effects of hydroquinone, eikonogen, rodinal, amidol, and "cristalos," using various alkalies, or, in some cases, none, with what I have called the " standard pyro and soda developer ; " but this paper has grown to such an uncon- scionable length, that I must leave the results of these experiments to some other communication, or to limbo. I wished to say something about Messrs. Hurter & Driffield's method of determining the sensitiveness of plates, but shall merely now say that it seems to me by far the nearest approach that.has yet been made to a perfect means of determining the sensitiveness of plates, taking into account, as it does, the useful densities, instead of the faintest detail, as heretofore — yet not perfect. The reason why I consider it not perfect will be understood from the objection that I have to any definition of a perfect negative that has yet been given, other than that negative thAt appears perfect to the man who makes it, the assumption being that he is a man of skill, and of something more, and knows what he wants eventually to produce, to wit, a picture. I wish, finally, to express my gratitude to my colleague, Mr. C. D. West, M.A., Mr. K. Arito, and Mr. 0. Kondo, for their invaluable as- sistance in all the experiments described. I'.S. — Just a word about there-reversal that we read of as arising from very prolonged exposures. I have tried to get this often enough without success, and determined to make a supreme effort this time. The long sensitometer was used, and plates were exposed to the full blaze of sunshine Ifor times from quarter- second to 34 mins. 8 sees. There was not a trace of reversal, developing either with pyro or with ferrous oxalate. This correspouds to an exposure in the camera, to a brilliantly lighted landscape for many days, with the conditions as they common^ are. I think that, if it is possible to prove a negative, these experiments prove the non-existence of reversal in the ease of gelatine dry plates. I should like to know of any one who has had actual experience of re- reversal in the case of gelatine dry plate.', or of any other plates, for the matter of that. Bhiurks on Professor Burton's Paper dt Mb. H. M. Bldeb. A ORKAT many of Professor Burton's earlier remarks seem to be due to the unfortunate confusion caused by the special meaning given to the word " density " by Messrs, Uurter & Driffield. His opinion as to the range of gradation commonly met with in camera work differs very 4C6 THE BKlllttH JOURNAL OF PHOTOQRA.PHY. [July 21, 1893 largely from that of Captain Abney, who, at a meeting lately held at the Camera Club, said that as a rule this range did not much exceed inten- sities of light in the ratio of about thirty-three to one. In the example quoted at the time, it was asked what was the ratio of the light reflected by the white and black in the case of a figure draped in black velvet with a white shawl. t, . Passing on. however, to the main object of his paper. Professor Burton has abundantly proved in a qualitative manner that the ratio of gradation in a negative is dependent on the time and method of development, and his numerical formulic for the strength of pyro developer to compensate for increased exposure is a very interesting one. It seems, however, that a mere qualitative proof of this fact is not of very great importance, except in so far that it will tend to reassure those photographic weaklings who have been frightened by Messrs. Hurter & Driffield's much-misunderstood paper into disbelieving the evidence of their own experience. What would seem now to be wanted is a complete quantitative investigation of the whole problem. It is, of course, a long and laborious task, but it may be lightened by working systematically at it. I would point out, that from Professor Burton's paper it is almost impossible to really repeat his experiments, since certain important factors are left almost unnoticed. The prints themselves, as the author has pointed out, show many irregularities, and this was inevitable from the method of work. It is easy to see that in the feeble light of the developing room it is a sheer impossibility to carry out such instructions as were given to Professor Burton's assistant with any certainty, and I think that it speaks very highly for Mr. Arito's care and ability that the irregularities are not more marked than they are. Then, again, it is impossible to draw any very definite conclusions from mere inspec- tions of negatives and prints. It is an absolute necessity, in carrying out such work as this, to make actual measurements of the transparencies of the resulting negatives. No doubt, if Professor Burton had done this, the irregularities would have been more marked than they are, for it has been pointed out again and again, by Captain Abney and others, that the eye is utterly untrust- worthy as a measuring instrument by which to judge of the density of a deposit on a photographic plate. If there is any truth in a formula which I put forward at the Camera Club Conference of the present year, to represent the action of light and development upon a photographic plate, it ought to be capable of accounting for such results as those of Professor Burton's ; and, if any one will take the trouble to examine the effect of varying the two constants that depend on development in this formula, I think it will be easily seen that it will account in a large measure, and, I believe myself, entirely, for these results, and that even the complete formula of 'Messrs. Hurter & Driffield fails to do so. Professor Burton's paper is an interesting and very valuable one, and would have been far more so if he had not trusted so much to human judgment, both in making his experiments and in interpreting the results. By this I mean, what is wanted is a series, and a long one, of definite experiments on plates definitely exposed, developed in deve- lopers of known constitution for known times (not until a certain appear- ance most difficult to seize is shown), and then measured carefully, so that the results can all be numerically expressed. OUR PICTOEIAL FAILUBES. By the Ekv. F. C. Lambert. Let me commence my remarks by a confession. In a moment of vanity I was induced by the irresistible suavity of the Hon. Secretary to promise a paper for this meeting on some art topic. Little did I then think how difficult it would be to find a suitable subject. Thns once more the old saw is illustrated, " Pride goeth before a fall.' At the moment of my rash promise I had failed to realise the numerous conditions of the case ; and thus more time than I care to tell has been consumed in search of a subject — in a way, too, that has made me feel the force of one who describes his fruitless chase after a certain all-too- familiar, but unmentionable, insect. " No sooner you put your finger on him, but he isn't there at all, and the reason of that same is directly you catch him you miss him." Thus, again and again have I thought I had hit upon something new, only to find it not true ; or again on something old and true, but so very conventional that it could no longer be held to interest a conventional gathering. Or again, if a subject presented con- ventional and convivial features — for the two are in our case somewhat closely akin, if not interchangeable terms— then I grasped it, only to find it was neither new nor true. Hence I reach the crux of my apology. In our " failures," we each may hope to find some conventional, i.e., extenu- ating or mitigating, circumstances. Our failures are, alas ! only too true ; their truth is only too deeply driven home by their painful frequency. And yet the cloud has a silver lining. Our failures are ever new ; their newness and freshness has all the doubtful charm of being very much " up to date." I shall presume that most of us when visiting a photographic exhibition have at least two objects in view : Firstly, to see and as faras possible enjoy the work of others ; secondly, to gather hints and information from the work which has most favourably impressed us. The second of these only concerns us for the present moment. I venture to think that I am speaking for many others as well as myself ^ when I say the general impression, after visiting an ordinary photographic exhibition, is one of failure rather than success. To put the matter in other words, the number of pictures that one thinks about afterwards, or would care to possess for constant companionship on the walls of our living rooms, is exceedingly small. Would half a dozen out of every hundred exhibits under or over-state the mark ? Leaving a liberal margin for per- sonal taste, the nett result is that the majority — a saddening majority — are, if not failures, certainly not definite successes. There must be some grave reason for so significant a conclusion. Nor should the inquiry fail to interest, stimulate, and add to the value of the discussions of this gathering. On this point I would suggest the following points as being contributory in varying degrees to the general product of non-successes. The free discussion of the topic, whether leading to rejection or aeeeptanoe, cannot fail to draw some attention to the subject, and hence tend to diminish the number of failures. But I am not without hope that the results may be distinctly positive and fruitful in producing a greater number of distinct successes. Some suggested reasons of our pictorial failure : — 1. The Commonplace. — I venture to put this first because it seems to include — in somewhat free-and-easy terms, I admit — the majority of the nnremembered. This includes the characterless many, who neither please- nor pain — everything about them, selection (save the mark! ), exposure, printing, mount and frame, are simply " middling." Hence we are utterly indifferent as to their future fate. Why are they entirely lacking in interest, in the general absence of any positive conspicuous defect, you ask ? I reply, the worker in his so-called selection has exactly failed to select. He has taken things as they are. Selection surely implies rejec- tion as well as acceptance. In the cases before us it has been all ac- ceptance and no rejection. Nay rather, may we not say that the general tendency, where it shows any thought at all, points to over-crowding rather than selection ? Perhaps collection would be a better word. The " art of leaving out " in many cases, if known, is sternly ignored. A large element in the commonplace is the presence of so much which is utterly unessential, immaterial, uninteresting, and hence discursive and generally weakening. It acts like a diluent. A teaspoonful of the best and ' purest and strongest whisky would have but a poor chance in a gallon of the purest agua-puminhus, negative and innocent as that diluent might be. 2. Next oomes Indefiniteness. — By this I do not refer in any way to the method of producing the out-of-focus or so-called fuzzygraph method of working. The indefiniteness here indicated is that due to lack of definite aim or intention. This is the man who " aims at nothing and hits it." We are assisted to recognise this class of work when it appears with such delightfully bewildering and vague titles as " a study," " a nocturne," " an effect." The only, if any, effect generally produced is that of bewil- dered inquiry, or perhaps a reminder of some recent puzzle picture sub- scribed, "Find the dog, the policeman, and the baby." Impressionism may be all very well in its proper place, provided always that the artist has an impression and some reasonable power of express- ing it. But if the would-be-impressionist desires to snatch applause by feeble imitation, or shelter his incompetence under vague titles, then he is in no way a true friend to the progress of photographic art. The third place maybe assigned to the defects duetoimifafwH. The old saw which says that "imitation is thesincerest form of flattery " requires- its "teeth setting" more in a line with actual fact. Experience seems to show that it is only those seeking spurious greatness in the cloud of dust they raise who find any acceptable flattery in the mimicry of a tail of followers, who, in turn, having no ideas of their own, arc ready and willing to accept such ideas of their leaders as require the least, if any, effort to assimilate or digest. It may well be doubted if any one who has thoughts, methods, or ideas, of his own of any real value would accept on any terms the fulsome- flattery of brainless imitation. Would Shakespeare, Milton, or Tennyson, Reynolds, Constable, or Turner, have turned aside one hair's breadth to win a following of those who at best could only accentuate the defects of their leaders, and dilute beyond recognition their choicest merits. We may look, and look in vain for any great artist in form, colour, song, or stone, who has wrought hit way to lasting greatness by imitation, sueh as is not altogether unknown by those who are eager to be dubbed photographic artists. Earnest, con- scientious, and laborious study and analysis of the greatest works of the greatest men is no doubt of inestimable service to those who aspire to be July 21, 18)3] THE BRITISH JOUKNAL OF VriOTOGRAPHY. 407 tlieir compeers, but true atudy points to principles rather than rales, results rather timn methods. The student will be as anxious to avoid the semblance of imitation as he is desirous of reaching, if not outstrip- ping, the triumphs of the masters who inspire him, at the same time there will be an equal anxiety to make his work his own beyond the chance of merit it may possess being suspected of having been filched, or even borrowed, from the work of another. Much has been said, some- times with truth and sense, and sometimes otherwise, on the subject of schools in photography. Tlie pages of the history of painting teach us that " fchooU " are not to be manufactured at the whim and fancy of in- dividuals. The causes at work were deeper-seated and more fruitful than ■the passing popularity of an eccentricity or novelty. Furthermore, this difference tietween painters and photographers seems to lie on the surface, ■whereas among the schools of painters each and all profess (and practise with varying degrees of truth) to study in and appeal to nature — each school professing itself to be a more faithful exponent of nature than the others, and in that sense all are impressionists — while, on the other t^and, photographers with an equally charming candour, one and all pro- fess to study in and appeal to the same great school, nature ; yet it would seem as though not a few were content to have their seeing and thinking •second-hand, since by their productions, their efforts show an industrious Rand not always unsuccessful effort at imitating the productions of each Pother. 4. An inversion of the means and tlie end must be held in part respon- sible for some misspent energy. An all-consuming anxiety to display to pts utmost limits the possibilities of some instrument, the capabilities of Dme process, is a terrible temptation to many. Microscopic definition, biting sharpness, topographical precision are phrases that have had their May and due regard. Tlie transitional phase of differential focus is pass- Jong into further development of astigmatic distortion, or the suppression lof definition by diffraction. In those of an independent or experimental turn of mind, their means ■ may, and do, at times, produce results which are not only extremely in- teresting, but also have a value as being expressions of a personality, but the counter- balancing disadvantages come pari passu. No sooner does one see a success snatched by some pioneer, but it is quickly imitated and diluted ta such an extent that its virtues, even though few, are ■ignored, while its defects, no matter how many, are each and all repeated until the unfortunate founder, or leader, of the school is saddened by " ading that the world only sees his excellencies or his multiplied detects. The " fatal facility " of production tempts the great unthinking crowd to nsh headlong down the course of destruction, leaving in their trail i" wrecks and ruins " of wasted material. Kow do they rush for the (iotorial crown through /-61 of a highly corrected symmetrical doublet, now through a pinhole, now it is a spectacle lens, now an astigmatic lens, laving tried and found wanting any and every lens, and finally no lens fct all, inspiration whispers, " Try a new printing process." Tnus, from tiocolate-boxlid polish and gloss to roaghest sand-paper is but a step I each and every case an anxiety to display the means, rather than use be means according to the end desired, meets us again and again, and cconnts for gome proportion of the pictorial failures. 5. Lastly, some small place must be found for the failures due to mis- Urected rivalry. That a certain picture obtains a measure of notice is aongh to set some at work to outstrip this picture by some slight advance lither in subject, pose, lighting, or other method or means employed. The results of such rivalry must of necessity be unhealthy, as being the l^ro juct of jealousy and imitation. All thinking art workers are agreed at the first quality of success is that the work attempted shall be felt worthy of the effort expended on it for its own sake. In other words, if man's heart is not in his work, there will be very little art in it. )bviou3ly, then, where one attempts to imitate and rival the productions of another, if is not a case of trua affsotion, bat the green-eyed monster •that is secretly at work. To sura up briefly, our inquiry seems to point to a handful of causes lending to produce work which, if not distinctly and definitely failures, are undoubtedly not successes. Let us go, In imagination, five times sound the walls of a photographic exhibition. On each journey we shall weed out such pictures (or rather prints) as show the following short- •eomings : — 1. The commonplace, due either to overcrowding of entirely extraneous, ■uninteresting, unessential elements. For the most part, if they are not positively offensive, they are absolutely uninteresting, dull, and character- less. They are " tlw jeU^-jith order." 2. The indefinite or meaaingleas, that have nothing to say, and say it ■a silent elo-iuenoe. Their result, if any, is ooly to irritate. These are ' tlie pennt/ piizik-card orUnr," S. The feeble imitation class, wherein what little excellence (often dinicult to find) has been obtained by other than honest, straightforward, individual, and personal work. These we may dub the "petty larceny ctann. " 4. Means v. end, where the worker is anxious to display bis dexterity in the use of his tools, perhaps with the hope that, as " fine feathers make apparently fine birds," so, possibly, artfulness may pass current for art. Let us call these " llic conjurimi-lrick clann." 5. Rivalry, where one worker endeavours to build a fame upon the head of another worker ; not because he cares about the subject, but because he is anxious to try and make himself the larger by ungenerously belittling another probably more modest worker. As it is not easy to find a name for these, perhaps we may best pass them over as the " nameless unirorthies." Having removed, gently but firmly, the foregoing five siftings, it may be reasonably hoped that whatever, if any, are now left will have suffered no loss, but gain rather, by having passed into " Standard Six." PHOTOGRAPHy AND THE GREAT£BAREIER BEEF.' Mb. Saville-Kent's work is the outcome of an eight years' residence in the Australian colonies in the capacity of Inspector and Commissioner of Fisheries, and he has been fortunate in securing much valuable assist- ance from scientific and oflicial persons. The scope ofjthe book " is to render an account, in clear and popular language, of the most highly attractive subjects, from a commercial and biological standpoint, that are associated with the Barrier region, and in the former connexion more especially to indicate the lines on which, through the application of scientific methods, more remunerative returns than heretofore are to be realised." It may be explained that the Great Barrier Beef of Australia is an enormous coral region between Torres Straits and Queensland, " built up by the direct and indirect agency of soft-fieshed polyps of multitudinous form and colour, and teeming with animal organisms of myriad form and hue representative of every marine zoological group." Necessarily the book is largely, although not exclusively, of scientific interest, the general reader being here and there kept in mind in some of the descriptive sections of the volume, while, when Mr. Saville-Kent comes to discuss the potentialities of the fascinating region he has so ably laid bare for us, the commercial spirit of the age will find plenty of food upon which to feed and thrive. After discussing the various theories as to the formation of the Great Reef, Mr. Saville-Kent proceeds to treat of and describe its corals, coral animals, and allied organisms ; the pearl and pearl-shell fishery ; the BCche-de-mer or Trepang fisheries ; com- mercial oysters of the Barrier district ; turtles and the turtle and tortoise- shell fishery ; the Dugong fishery ; commercial sponges ; food and other fishes, &c. That which imparts photographic interest to the work is a series of forty-eight large coUographic plates illustrating the text. It is safe to say that few, if any, recently issued books are more indebted to photo- graphy for the beauty and technical charm of their illustrations than Mr. Saville-Kent's splendid volume. The pictures are from Mr. Saville- Kent's negatives, which have been coUotyped by the London Stereoscopic Company and Messrs. Waterlow ; and, while paying every tribute to the undoubted excellence of the originals, we are free to declare that seldom have we met with such delicacy, fidelity, finish, and studied carefulness of printing as in the work of the firms named. Views are given of coral structures of various kinds under natural conditions, of the pearl and pearl-shell fisheries, the Trepang fishery, anemones, oysters, the fishing industries generally, marine fauna, Ac. Of many of these illustrations it is claimed that they represent the first occasion on which the camera has been employed for the systematic delineation of such subjects. It is only at rare and uncertain intervals that the reefs are uncovered to the extent in which in many instances they are here depicted. Two of the illustrations show Mr. Saville-Kent with his camera, the lens of which is pointed to the object contained either m a small pool or in an improvised aquarium in a bucket, with other objects of interest scattered about. To employ the camera in this manner, it is fitted in a frame to which the stand is attached. In addition to the collotype, sixteen chromo pictures of fishes, i&c, from Mr. Saville-Kent's own water-colotir drawings are given, these being by Messrs. Riddle & Couchman. We have no doubt Mr. Saville-Kent's finely got-np work will take • Th4 Gnat Borrin- S«f of AiutraUa : \l» Produci* and Pi)(«t>al>(MS. By W. SarlUe-Kent, F.L.S F.Z.S. London: W. U. Alleo k Co. Limited 13f Waterloo- plaoo, 8.W. 468 THE BRITISH JOURNAL OF PHOTOGRAPHY, [July 21, 1893 high rank in the library of the biologist, and in contributing to this result it is pleasant to note that, both in his own camera work and in the re- productions from his negatives, the part played by photography is con- spicuously paramount. i^etos anlJ Botes. NORTHEBN PHOTOOBAPHIC AND SCIENTIFIC ASSOCIATION. — July 22, Eich- mond. Hackney Photographic Socistt.— July 25, Exposvre Meters and Tables, by Mr. W. F. Feiiton-Jones. GosronT PHOTOiiHAPHic Sociktv.— July 22, Bishopstoke; leave Gosport at twenty-four minutes past two, p.m. Mr. C. Crescknt, of 20, Paternoster-square, E.G., has sent us a small sample of the "Crescent " sensitised paper, which we have found to be of good quality. Photographic Club.— July 2G, CoUndin-chlaride Printing. August 2, Report of the Convention Delegates. 7 (Bank Holiday), Outing to High Wycombe. Mfs.srs. Percy Lund & Co., St. John's-street, Bradfonl, have sent us a sample of gelatine, which retails at Is. 6rf. p»r pound, which is intended for collotype work. It appears to be suitable for the purpose. East London Photographic Society. — August 8, On the Desirahility of Suitinij the Printinij Process to ihe Negative, with illustrations, by Mr. Bennett. 22, Demonstration upon chloride Printing and Toning, by Mr. Copping. "Thk Pbinck of Wale's Smilr."— Mr. F. G. Smith, photogrrapher, of the Quadrant, Richmond, S.W., sends us a cabinet size portrait of the piiiice of Wales, in which H.R.H. is lifting his hat and smiling heartily in acknowledg- ment of a salute. The picture is evidently .an enlargement from a small negative. Birmingham Photographic Society.— July 2'i, Social Evening. Members are invited to bring prints and negatives to all the Tuesday evening meetings when no special paper is announced. 26, Lajt day for sending in photographs for the Charlecote Excursion Competition. Photogeaphic Society ok Great Britain.— On July 25 there will be a Technical Meeting at No. 50, Great Russell-street, when a discu.ssion will take place on The Use of Uncorrected Microscopic Objectives v'ith Coloitr-correctcd Plates, Mr. Piingie will introduce the subject, and show specimens. Messrs. J. Bishop & Co., of 19, Princess-road, Regent's Park, N.W., were recently honoured with a letter from Princess Victoria Mary of Teck, accepting a picture, a platinotype enlargement of the Royal Family in Windsor Park, framed complete, as a wedding gift, and they have just received from the Duchess of York a letter thanking them for it and saying that it gave Her Royal Highness great pleasure to receive it. Mr. W. T. Whitehead, of 7, St. Paul's-churchyard, formerly with Mes.srs. Downey, Mr. Van der Weyde, &c., is making a speciality of designs for the backs of card mounts, headings, initial letters, &i'., of which we have .seen many artistic and tasteful examples. Photographers who may desire to have designs specially prepared for them could not do better than communicate with Mr. Whitehead, who also undertakes the working up of bromide enlargements, and tuition of the Air-brush, in the use of which he possesses a very high degree of skill. London and Provincial Photographic Association. — The following are the arrangements of the London and Provincial Photographic Association during .Tnly and August :— July 20, Members' Open Night. 22, Outing to Totteridge Station, three o'clock ; over Mill Hill to Hendon. 22, Less Cvsto- mnry Ortlwchromatic Photor/rophy. August 3, Members' Open Night 7, Bank Holiday Outing to High Wycombe. 10, Film Working, hy Mr. W. M. Barnes. 12, Outing, the Zoo. 17, Delegate's Repoit of the Convention, by Mr. W. D. Welford. <= i , i Midland Camera Club.— The first Annual Exhibition of the Club will be held at the Botanical Gardens and College Grounds, Moseley, Birmingham, to open on .Monday, October 2, 1893, and close on Saturday, October 14, 1893. It will be under the patronage of Bight Hon. Joseph Chamberlain, M.P., Sir John Jaffray, Bart., Sir Walter Fo.ster, M.P., Sir James Sawver, Right Hon. Jefte Ceilings, M.P., Austen Chamberlain, Esq., M.P., &c. There will be clas.ses optn to professionals, amateurs, and manufacturers. Particulars and entry forms may be obtained of the Hon. Secretary, 4, Woodstock-road, Moseley, Binninghaui. "Many people," says Dry Plates for July, "are greatly in doubt as to the coirictness of the U. end D. methcd of speed readings through a series of densitits, instead of the last faint indications of deposit in the feebly exposed liortions of the plate. To them we would ask : Why did speed-testing with thcWaintrkcsensitometer fail to give even an appioximate indication unless the last few faint numbers visible were not taken into account? Yet such was the cafe, and this point generally agreed on. Negatives, as a rule, consist of a series of densities extending over a considerable range ; surely, then, a system which rtads through the whole extent of that range must, as a matter of con.mcn Einse, be the right one, and to the point." The Convention Exhibition. — In our notice of this Exhibition last week, the enlargements from negatives by Messrs. Byrne, Richmond, and Messrs. Cox & Durrant, Torquay, should liave been included among the exhibits of Messrs. M. & T. Scott, Edinburgli, instead of those of Messrs. 0. Sichel k Co. A Prize Medal for Beb Slides. — At the Royal Agricultural Society's Show- at Chester, in Class 345, " The most interesting and instructive exhibit of any kind connected with bee-culture," a sUver medal was awarded to Messrs. Newton & Co., of 3, Fleet-street, for an exhibit of lantern slides of bees and bee-culture, made from negatives by Mr. T. E. Freshwater. We have before referred to this series of slides as being of great interest, especially to bee- keepers, &c. The Imperial Dry Plate Company announce the following awards in the competitiou for negatives on Imperial plates, which closed June 30 : — First prize of 4?. 4s. to Mr. F. Cherry, Vice-President North Middlesex Photographic Society ; second prize of 3/. 3.s. to Mr. P. H. Lamberts, Amsterdam ; third and fourth prizes are divided between Messrs. .*.. H. Duncan, Glasgow, and F. G. Heseldine, Leeds. A series of competitions, closing October 30, will be an- nounced during the month. Mr. J. Hubert, the well-known photographer, of Mare-street, Hackney, ha become the editor of the Hackney Jiecord, a small local sheet from which we extract the following unique obituary notice : — "On Monday, July 3, Mr. ■ was solemnly conducted to his last resting-place, accompanied by thirty-five carriages, whose occupants ought to feel deeply grateful to the departeil for having been permitted to don their best holiday attire, and pass in state through an admiring multitude." The "Talmer" H.vnd C.\meba.— Messrs. Talmer & Earner, of Blackburn, have issued an illustrated price list of the various forms of the "Talmer" cameras which they are now manufacturing. These include hand, stereo- scopic, field, .and studio cameras. An eight-page pamphlet supplies a clearly written guide to the use of the "Talmer" hand camera, from which we make the following extract relative to the means employed to avoid the omnipresent enemy, dust: — "In most hand cameras the plates are contained in roughly blackened tin or zinc sheaths, which, during the operation of changing, are shot up or down, or fall from the vertical to the horizontal, rubbing against each other, raising an incredible amount of dust, and filling the interstices of the camera, and finally settling on the jilate. Nor is the amount of dirt reduced by the continual scraping of tke sheaths against the bare wood of tlfce- interior, nor by the wear and friction of other working parts inside the body of the camera. Comprehending these drawbacks, and following the adage that prevention is better than cure, we have adopted sheaths of thin pen steel of smooth and dull surface. Being made by special tools, they are absolutely uniform in size, iind hold plates of any thickness up to register. Tlie inside of the chamber in which the sheaths are contained is faced with brass plates, the sheaths and other metal parts work metal agains 'metal, ensuring absolute freedom from dust and uniformity and certainty in action." ©ur IBlittorial Cai)lt. Snap-shots at the Convbntion. J. A. SlNCLAIfi. The har.d-camera yiews token by Mr. Sinckir at tlio Convention at once indicate the hand and head of a master — the head to select and the hand to manipulate. Tliese chefs ctoeuvre of hand-camera ■nork are printed in platinum. The first to claim attention is a small group, taken on board the boat the Princess Royal, in which, on the memor- able rainy Tuesday's excursion, such a large number of members availed themselves of the kind invitation of the local camera clubs to visit the Yealm and Tamar rivers. The scene represents the Presi- dent of the Convention with a surrounding of ladies, to whom he has been engaged in telling one of his ever-ready, genially funny stories. The amusement depicted on the ladies "faces shows that the humour of the story is beirg well appreciated. This, we venture to predict, will turn out to be one of the most popular of all the pictures taken during the Convention week. Others represent Holes Hole, a landing- stage on the Tamar. In this picture the steamer is seen made fast to the pier to afford the members an opportunity of visiting Cothele- House, a venerable ivy-clad mansion dating from 148.'), and its very beautiful grounds. This is the most perfect example extant of the- Tudor fortified mansion. Sir. Sinclair's collection includes a charming view of this mansion, which is buried in oak, ash, and chestnut-trees. Other pictures — for they are pictures rather than mere snap-shot; photographs — represent Saltash and its famous Bridge, the Pool, Plymouth, and its shipping. These were all taken with an " Ideal,'^ with a five and a half incli lens capable of focussing. Walter D. Welfoed. Mb. Wklfobd is well known ai en expsrt snapshotist, ani hi ha.?- employed h's hand camera with evcel'ent effect in carryirg away reminiscences of many humorois ■;r.upings. Ileie we haveagroip of five members listening to the e'o ^uenc* of Mr. Bir.' Acres, who, witb I July 21, 1893] THE BRITISH JOUBNAL OF PHOTOGRAPHY. 469 animation, is adducing reason:) why this scene rather than that other should be selected for ii short walk out. There is a fine view of the steam launch and the little flotilla by which the members were conveyed from Totnes down the Dart to Dartmouth. Another shows one of the most modern men-of-war at anchor in the Ilamoaze. Here we have a great concourst; of people assembling on the IIoo to secure pood places from which to witness the fireworks that are to be let oft after dark, and there we have individual specimens of the genu* homo armed with camera and stand, or of ladies with hand cameras. These are all in Mr. Welford's usual excellent style. USttHino^ of Sboctette)e$* MEETINGS OF SOCIETIES FOR NEXT WEEK. I>»t« of MraUnll. Name of Society. Place of Meeting. July 2* Abso. Stndio, Nether^te, Dundee. Jubilee House, Homsey-road. N. Greyhound Hot«I, Richmond. Club Room, Colonnade Hotel. 50, Great Russell-st., Bloomabury. 206, Mare-stroet, Hackney. 21 „ 24 „ 25 „ 25 25 Binuintrham Photo. Society ... Groat Britain (Tochnical) „ 25 „ 25 Springfield Barracks, Lancaster, 165, Constitution-street, Leith. » 25 .. Leith .... 25 „ 25 „ 26 . Bath Roy.Ltt.&Sc. Inat., Terrace-walks, „ 28 Bank Chambers, Hai^reaves-street. The A.S9eml>ly Room.s, Hipb-road. Anderton's Hotel, Fleet-street,E.C. K 26 „ 26 . . „ 26 .. 27 ;: 27 : ; Halifax Photo. Club Mechanics' Hall, Halifax. „ 27 Hall 71, Prospect-street, Hull. Rooms, 15. Dawson-street, Dublin. Percy -build ins: s, Klwrle-street. Champion Hotel, 15, Aldorsirate-st. The Lyceum, Uaion-street.Oldham. « 27 „ 27 Ireland „ 27 „ 27 „ 28 Cardiff „ 28 Public Hall,George'Street,Croydon, „ 28 „ 28 "••The Palace," Maidstone. „ 28 Tenby Hotel, Swansea. Ohiswick School of Art. Chiswiok. „ 28 West liOndou „ 29 Hull 71, Prospect-street, Hull. i LONDON AND PROVINCIAL PHOTOGRAPHIC ASSOCIATION. JOLY 13,— Mr. J. S. Teape in the chair. The Chairman showed results of a recent onting to Fobbing, Essex. GETTixa Rid ok Halation in a Negative. Mr. T. E. Fkkshwater asked the best way of getting rid of lialation in a negative of an interior with a large window. Sir. P. Everitt would vignette the window in the frame. He had found the use of methylated spirit unsatisfactory for reducing purposes. Mr. G. W. Atkins had used emery powder in oil with satisfactory results. Mr. Fueshwatbr asked whetlier it was essential that the halation should be got rid of. In the photograph to which he referred he got the window just as looked in the subject. The CHAIB.MAN suggested the reduction of halated negatives and workiag them up with a pencil. He had trietl the ii.se of a knife for scraping away parts of a negative, and said that it seemed to make tho.se parts much denser. Mr. W. E. Debrnhah remarked that varnish restored the parts to their onlinary density. The meeting was largely occupied in the .irraugements for outings and subjects for discu.ssiou. Hackney PhotogrrapMc Society.— July 11, Mr. R. Beckett in the chair. — A question was asked, "What is the best way to restore old negatives stained yellow!" Mr. HuDSONadvised the use of a weak hydrochloric acid bath. Mr. MooBK thought bleaching with mercuric chloride and redeveloping with ferrous oxalate better. The Chairman said often stains were caused by insufficient fixation. A cjuestion was asked as to the approximate exposure for enlarging on slow bromide. The Hon. Secretarv said there were many things to con- sider, such as stop, rapidity of paper, &c. If for lantern enlarging with slow Eastman paper, aperture /■4 for a fairly developed negative, enlarging from a quarter to 10 x 8. he would give about two minutes as a standard from which to work. Mr. Harversox had (by daylight) on rapid paper given one minute witli/-16, enlarging from a half plate to la x 12. Mr. Grant advised testing by using one piece of paper and giving varying exposures. Mr. NuNN then read a paper on Rcducliun of Lantern Slides. He preferred always to reduce his sliiles as grain was lost, and to do them by daylight, as they could be done much quicker. In developing always be rJean — have clean dishes, fingers, and filter the develojicr ; dust your plates. He then showed a long tunnel-shaped apparatus which he used for reduction. When using daylight a white reflector was placed so as to reflect evenly on negative. Aim at full exposure and full density ; forciug was a mistake. Clearing was advisable. Mr. Gosling asked if much advantage was gained by reduction rather than contact, and was informed that every defect was reduced correspondingly. Mr. I'KNBV asked whether thin negatives were better tlian dense ones. Hr. NuftR said he had found them so. The Chair.man saiil copying always sharpened np more than when in contact. The Hon. Secretary thought Mr. Nunn's ap)>aratus too cumbemonie, and ailvised a bellows, as it could lie shut up and take lens room. Aahton-under-Lyne PhotOKrapbic Society.— On Saturday last, July 15, th» above Society's ramble was to Chew Brook, near Greenfield, with Mr. C. K. Redfern, .I.P., as lea MY PIRST DAOIERREOTYPE. By VALENTINE BLANCHABD 468 JOTTINGS. By COSMOS 4i4 STEREOSCOPIC PHOTOGRAPHY. By W. I. CHADWICK 4M SOME POINTS IN CONNEXION WITH DEVKI.OPMEST. By .1. STKBBY .... 456 PHOTOGHAPHIC CONVENTION OF THE INITED KINGDOM 455 W LATITUDE IN EXPOSURE AND SPEED OF PLATES. By F. HUW- LZoK^TEB, PU.D., ASU V. C, DKIFFIELD 4G6 Paoi CONVENTION—rnnliinKJ. ON THE POWER OF COJIPE»- 8ATISO IN DEVELOPMENT FOR VARIATION IN EXPOSURE. By W. K. BURTON 4 o u o o ►J c > O s t^'.t'ig-Ha.- 5 c ON 00 > X a. < o o H O X 0* o ►4 < •z a! O X m ca w X H ?: w P. ►J c C- • 3^ ."3 .5 -^1 = 5 . . . = s s JOhS .s §: 6c^ S- iSiXS I = X S £ H a^AZ S S :<: ^ OS ai Jot 2- 2 i 2*2. ii^ 6*6 '^ A m "* ■* t ■* -^ ^ ■* -r in tn tfi •/> J3 4) II ^ O S d M ft rortromrtcnc^ m c?i r*) ir ^ cj . ;^ • "3 r" Ed "-^-^ :s. vi f-liM -C ^ ui o c/j »n«o r*.oo a> o >• ci A ^ ino fioo •-•H.H,^„e,ciciNnn«e*ci |il Hi "o B a g.S-r 2 • u » a i ? >•<;'' = =• 3 -J ^H^. , i g «=« g<: *^ 1 I THE BEITISH JOURNAL OF PHOTOGRAPHY. No. 1734. Vol. XL.— JULY 28, 1893. CORRECTING MICROSCOPIC OBJECTIVES FOR PHOTOGRAPHY. The American Journal of tlie Medical Sciences for this month •contains a paper by Professor Henry G. Piffard, ALA., "On a Suggested Improvement in the Correction of Lenses for Photo- micrography, Photography, and Photo-aatrography," a copy of ■which he has kindly sent to us. Twenty-five years ago, while microscopic object-glasses are admitted by the learned author to have been of excellent con- struction and well adapted to the revelation of the structure of minute objects to the eye, yet he says the photographs made by them were greatly inferior in clearness and sharpness to the virtual image appreciated by the retina, this being due to the lack of coincidence of the visual with the actinic focus. Dr. Pift'ard reminds us that, at the period mentioned, the art of photography was almost exclusively practised on iodised collodion plates, which, while very sensitive to the blue, violet, and ultra-violet rays, were but feebly so to the rays of less refrangibility. But, as these latter are more luminous, they impress the eye so forcibly, that the effect of the more refrangible rays is almost obscured when mingled with the others as in ordinary white light. It follows that, in order to obtain a sharp photographic image, it was necessary to either shorten the anterior conjugate focus or move the plate to a point nearer the lens where the actinic rays came to their posterior conjugate focus. Dr. Piffard, who is an expert photo-micrographer, is doubtless well aware of the system that was — nay, still is — practised by some in this country to utilise their objectives so as to ensure their acting both visually and photographically ; but, as he does not mention it, we shall, pending the publication of his excellent paper in externa on an early occasion, take occasion here to describe it, in the interests of those who are entering this fascinating branch of photography for the first t)ime. For reasons deduced from the foregoing, microscopic object- glasses must be slightly over-corrected for colour. AVe are now referring to such as are constructed of ordinary flint and crown glass, and in which category is to be found the majority of those in use at the present time. But under-correction for •colour is a condition for obtaining the sharpest photographic image. It is just forty years since the subject of photo-micrography was brought before the Society of Arts by the Rev. W. Towler Kingsley, and he met the then acknowledged difficulty of the non-coincidence of foci by recommending that a new front lens be made for the objective, so that it might be employed visually with the original one, and photographically with the new under-corrected one. This system is, however, very costly as compared with one which was suggested several years after- wards by Mr. F. H. Wenham, if wo remember aright. By it the object-glass itself is not altered ; but from its upper end, in which is usually screwed a diaphragm to prevent reflections from the interior of the brass mount of the objective, this dia- phragm is unscrewed, and its place taken by another cell, con- taining a simple convex lens, usually cut out from the centre of a spectacle glass. By having a few of these of different focal power it is then easy to select one which, when screwed in, shall, by its non- correction, impart to the objective the requisite amount of under-correction to ensure the coincidence of the chemical with the visual focus. When once the correcting glass has by trial been found, it is marked, and is always afterwards used when the special object-glass for which it was selected is employed for photo-micrography. The angular aperture of the latter is very slightly increased by this adaptation, but no one will consider this as a disadvantage. The system here described for securing the desired coinci- dence of the foci is, in oar opinion, greatly superior to that for attaining the same end by displacing either the anterior or posterior conjugates. Any working optician will, at a moderate cost, supply such a cell as we have described, and adapt to it a variety of uncorrected lensis of sucii variety of focus as will serve to correct, photographically, one's whole stock of objectives. Dr. Piffard says that tlie photographs of microscopic objects made twenty-five years ago " were crude and unsatisfactory, and were all made with what we would call low-power objec- tives." In justice to an eminent worker on this side of the Atlantic, Dr. R. L. Maddox, we must point out that this gentleman had, considerably anterior to that period, achieved great success in photographing, with a one-fifth of an inch objective, Polycystina from Barbadoes, together with several diatomaceous forms which accompany them ; several frustules of the Triceratium favus ; front views of the Surirella bi/roiis ; various specimens of Coscinodiscus, and other objects. We mention this ilpi-opos of Dr. Piffard's remark as quoted above, for we feel assured that this American scientist would be the last to withhold credit to an equally eminent English brother for what he has achieved in the early days of our art-science. 474 THE BEITISH JOUHNAL OF PHOTOGRAPHY. [July 28, 189 COMPARATIVE DEVELOPER EXPERIMENTS. A LARGE number of earnest workers in the field of photography find a pleasure in the class of work indicated by the title of this article ; but iu too many cases the results are either worth- less or too indefinite to be placed on record as serious results. Some hope of remedying sucli a state of affairs is the motive for the remarks that follow. The causes are mainly to be placed in two categories. First and foremost must be placed that most detestable — no other word is so suitable — method adopted by so many platemakers and writers of instructions and formula;, of giving the proportions of the ingredients in a manner that renders comparison of one with another most difii- cultj and wasteful of time to a degree that is most irritating. This is, of course, no new complaint ; but, if constant iteration will lead to its destruction, then "Delenda est Carthago" should be the watchword of all who would put an end to its incon- sistencies and its annoyances. We have lately set ourselves to try a series of experiments with one of the later developers — metol — and a good share of half an hour was wasted in arrang- ing for ready comparison the various instructions published, either by the makers themselves or in other ways. Percentage formula; were useful ; but, until the metric system is more commonly employed by the public generally, we think that grains per ounce will be understood and felt to be most practical by a larger number of working photographers. The manner in which every formula is set down should show at a glance how many grains per ounce, or per pint, or half-pint if preferred, of the various constituents are contained in the given quantity of developer when mixed ready for use. What a boon this would be, if all makers and formula-producers would adopt it, those only who are in the habit of making comparative experiments can say. To all such it is a familiar experience to find a couple of rival formulas being argued about which, upon being reduced to a standard, are found to be practically identical. The second of these two main causes is the hasty and in- complete manner in which conclusions are drawn, or rather jumped at, from the briefest of premisses. An experimenter tries, say, a new developer side by side with the one he usually employs ; the new solution flashes out the image at once, the Conclusion is rushed at and published that it is a " find," excellent for under-exposed pictures. Another is tried, and the image is only beginning to appear when the plate by its side is finished. The new solution is worthless, requires too long exposure, &c. Yet in each case the ultimate developing power may turn out to be the same, and no more exposure value can be got from one than the other. Then, again, it must be remembered that the ex- perience of many years has so narrowed down the range of fOrmuUc for pyro that the working limits are well known- strength of pyro, proportion of alkali to same, as also the value of alterations in the amount of bromide permissible. But to obtain such ready command of proportions of the various ingredients and their effect on results when an entirely new substance is used would require many trials, and it is the absence of trials of these variations that may make or mar for a time, at least — the future of any newly introduced developing agent. Before any decision can be fairly made as to the merits of such new substance, it should be tried in various strengths, with varying proportions of alkali and of bromide, and notes made as to the rapidity or slowness with ■which the image appears, and of all phenomena varying from ordinary experience. Let us now refer to one of the latest developers, metol. Any one trying it for the first time would be very apt at the outset to think that exposure could be reduced when it is used, for the image will flash out, and the surface of the plate present an appearance to that given by a fully developed pyro negative, while a companion pyro- developed plate has scarcely begun to show the high lights. How very needful to avoid rash conclusions here. Then, taking the published formula, we have been at the trouble to extract the data and reduce to an ounce standard (avoiding complex fractions by giving the nearest small one) the formula sent out by tlie maker, and those given in the reports of eminent experimenters. Pringle. Water . Metol Carbonate of potash . Sulphite of soda . . Bromide of potassium. FormnljB by j Agents. Agents.* Sexton. Eder. New. Old. 1 oz. 1 oz. 1 oz. 1 oz. ligr. aiKr- Sfgr. Sigr. ^5 ,. l'5i „ 11 » 11 „ 3i „ 10* „ 33 „ . 31 „ ¥ » None. i „ None. 1 3^ 11 31 1 oz. By this means a glance shows the peculiarity of each. In the first formukc published, the metol is to be used at a little over three grains per ounce, but now the agent recommends only one-third that strength. Messrs. Eder, Pringle, and Sextort give formulas almost exactly alike, save in the use of bromide. The first-named uses none, the second one grain per ounce, and the third a third of a grain. The new formula; of the agents in this country give six times as much potash as metol, the others only three times as much. There are two conclusions- that might be drawn from these fluctuating and varied for- muliB : First, that metol is so valuable that it can be worked almost hap-hazard; second, that its actual value is not yet ascertained, as the proportions of the given ingredients for a. particular purpose would not have such wide limits as above shown. Let pyro and ammonia be taken, for example ; if the ammonia of some formula; were doubled, hopeless fog would result ; if it were halved, the utmost value would not be ob- tained. We conclude by saying these remarks are neither for nor against metol ; they are made to show the necessity for care in forming judgments, and for varying the modes of using or mixing the developer before a logical conclusion can be justly formed. City and G-uUds of Xiondon Institute. — Uur attention has been called to several alterations that have been introduced in the programme of examinations for the session 1893-4, and other arrange- ments. Some new subjects are added, and others divided into two' sections. The honours examination in photography is one of them r (1) pure photography, and (2) photo-mechanical processes. And the practical examinations wiU be held in connexion with the honour* grade only. There are several other alterations with regard to th» examinations and regulations. For example, the practice of returning, or giving credit for, half-fees is to be discontinued. Some fees have been reduced while others have been revised. Furthermore, the list of teachers has been revised and rearranged. The Institute is making strenuous eflforts with regard to technical education, and it is to be anticipated that the new regulations will strengthen them particularly with reference to the really practical side of subjects taught. * For ordinary use ; variations are given for hard or soft negatives. July 28, 1893] THE BRITISH JOURNAL OB PHOTOGRAPHY, Art in Business Centres.— Since Sir John Gilbert gave wwral of his line works to the Guildhall Art Gallery, several other projeiits of pictures have been received. Now Mr. W. A. Murphy-Grimshaw has given his picture of the Haunted Mill, At present in the Royal Academy, to increase the collection. The Birmingham Art Gallery has also lately been enriclied by the acquisition of some fine examples of art metal and wood work, not in this ca.se by donation, but by purchase at the late Spitzer sale. Miinchester, as is well known, owns a large collection of fine works of nrt. While on the topic of art, The Academy says that the famous collection of drawings and sketches by old Masters, formed by the late Mr. John Malcolm, lias been deposited on loan by his son in the British Museum, whore it will soon be made accessible to students. A present of a colossal cartoon by Michael Angelo has also been made by Mr. Malcolm's son. If good photographs of such works as these were forthcoming, they would be of inestimable value to students ; many are, it is true, but they are usually issued at such a price as to be prohibitive to the ordinary struggling art student. Discoloured Glass Positives. — Amongst the odd work that photographers are frequently called upon to do is to produce •copies or enlargements from old glass positive portraits, If the picture happens to be in a good state of preservation, nothing is easier to copy in camera than a glass positive : but, in the majority of instances, it is not. These pictures, from being carelessly produced, and seldom or never being Tarnished, after a time become discoloured unevenly by a highly non-actinic tint, which causes camera copying to be very unsatisfactory. Most old hands know, though the new ones evidently do not, that, if the black varnish be cleaned from the back of the glass, the stains show but little, if at all, by transmitted light. There- fore they then use the positive as a negative, though a weak one, to print a transparency by contact on a dry plate, and from that make a negative for the end desired. The other day we were consulted as to the best way to produce an enlargement from a badly stained positive. On removing the black varnish, we found, as we expected, that the stains scarcely showed in the centre of the picture when it was looked tlirough. At our suggestion the positive was placed in the enlarging camera, and an enlargement made direct from it, as a vignette, on bromide paper. The result was a picture quite as good as if it had been made from an average ordinary negative. So good was it, that the method deserves a passing note for the benefit of novices. metric WeigrlitB and Measures.— The vexed question of weights and measures as regards photographic formula; seems to be as far off a settlement as ever. Whenever any new formula appears from the Continent, whence, by the way, the majority come, it is given in grammes and cubic centimetres, while English ones are written in grains and ounces. Now, notwithstanding that tables are given in the Alman-ac-s of the equivalents in one system to those in the other, we, and perhaps other journals also, are being csntinually asked bj- correspondents to convert a formula according to one system into that of the other. A few years ago the Photographic Club went to some considerable trouble to get other photographic societies to adopt the metric system entirely ; but this has not l)een generally followed. We were recently shown a set of gramme weights stamped "with their equivalents in English grains, but we were told by the owner of them that he had to do it himself. Of course, beyond the gramme weight, for photographic purposes, the nearest whole number is near enough. Fluid measures are to be had at some shops graduated on one side with ounces and drachms, and on the other with cubic centimetres. Thermometers are regular articles of commerce with the Fahrenheit scale on one side and the Centigrade, or Koaumur, as the case may be, on the other. Why, then, should not weights and measures marked with the two systems be universal ? The additional cost, particularly with the weights, would be merely nominal, and that would be repaid to many photographers by the general con- Fhotosraphs of the ZMEUky "Way.— Professor E. E. Oarnard, who has recently been on a visit to Europe, has brought with him some wonderful photographs of the Milky Way, which are simply a revelation to man}* of us. Ihese photographs (says the Obtervato)-y) were taken at the Lick Observatory with a lens made by Mr. Willard, of New York, in IS."*!), which ia one of large aperturn (six inches) and short focus (thirty-one inches). Such a lens tends t> compress, as well as intensify, the characteristic features of these stellar clouds, the large field allowing one to embrace any of thewj forms as a whole, and not in detail, as ifl the case when they are viewed with a telescope. The first photographs, showing the cloud form.i, were taken in August of 1 890, the portion of the sky being that situated in Sagittarius, and the exposure three hours fifteen minutes. A most interesting picture is that of a section of the constellation of Cygnus, near y Cygni ; this photograph shows some of those curious and almost weird dark spots and dark lanes the origins of which are very doubtful. Mr. Ranyard supposes them to be due to an obscuring medium between us and that part of the Milky Way, but Professor Barnard's opinion is that they are real holes in the cloud structures themselves. Two photographs, with different lengths of exposures (two hours forty-five minutes, and four hours thirty minutes), of the region about M. 11 in the constellation of Sobeski, raises an important point as regards the different structure of the Milky Way. The second picture exhibits details which considerably altered the con- figuration, not at all brought out in the first one. Not only in these photographs, but in several others of the Milky Way, this fact ha-s been noticed, and Professor Barnard suggests that there may be different orders or kinds of cloud structure implying distance or near- ness, or possibly an entirely different order of stars in point of actual size. Chicagro ZSxbibition. — A recent telegram informs us that the jurors in the Fine Arts Department have elected an Englishman, Mr. W. B. Davis, as president, and Signor Delnero, of Italy, and Signor Delcampio as first and second vice-presidents, with Mr. Dielman, an American artist. Mr. Thacher's plan of awards has been rejected in toto, and the following adopted : — A member of the jury will pro- pose a medal to a certain artist. Then this motion must be seconded and supported by a majority of the jurors before the medal can be awarded. As, however, the French, Danish, Russian, and Norwegian Commissioners were not present when the President of the Committee on awards made these concessions, it is understood that the countries named have decided not to enter their fine art exhibits for the jury's examination. This decision wUl, of course, to an extent, rob the competition of its international character. This " big thing" among international exhibitions seems to have been a more or less unfortunate affair from the very beginning. There have been the strikes and accidents during its building throughout, its chaotic state at the time of opening, and the allegations of "jobbery." Then there was the irritating monopoly with regard to photography, and the unpleasant friction about the awards. Next, the late lamentable fire. Lastly, and that will weigh heavily with our American cousins, the prospect of a financial failure in proportion to the magnitude of the undertaking. Bv the way, we learn that the American liner companies are not reaping the harvest they expected from British visitors to the West. Last year, in almost every family circle, some one was going to Chief go; now, it is surprising how many, for some reason or other, have abandoned the idea. RATIO OF GRADATION ON POSITIVE PAPEltS. The invaluable researches of Messrs. Hnrter & Driffield in connexion with the exposure and development of negatives should stiidulate photographers to inquire more closely into the character of the various descriptions of films employed in the production of their prints or positives. Not only do these, as is well known, vary in actual sensi- tiveness, but also in the way in which they render the gradations of negatives of different densities, some giving the best rendering of generally dense images, others again behaving better with thin or delicate negatives. * With no printing surfaces with which I am acquainted does this difference exist to so great an extent as wi th ge latino-chloride paper TC THE BRITISH JOURNAL OF PHOTOGRAPHY. [July 28, 1893 which can be made by varying the formula to work to perfection with either hard or delicate negatives, though generally it may be accepted that the commercial papers work better with a rather thin negative, and give a good result with negatives too thin to print satisfactorily upon albumen paper. The latter of late years, since the introduction of ready-sensitised papers, has materially changed its character, being both more sensitive and more generally applicable to thin negatives than was the case when the home-sensitised article was in use, the alteration being, no doubt, due to the introduction of new organic salts of silver. But, though the poative papers are known to thus vary, little or no attempt has ever been made to adapt the paper to the character of the negative. In days gone by, if a man had to print from very thin negatives that were worth the trouble, he would use a stronger sen- sitising bath than usual, perhaps also employing a more heavily salted paper if obtainable. Tliat was about the only direction in which the chemical treatment was varied, except perhaps in carbon printing, where exactly the reverse means were adopted to produce the same result ; in other words, for thin negatives a weaker bichromate solution is employed in sensitising. Beyond this, there were various methods of .shading the negatives with tissue paper, or matt, or coloured varnish, when the image was too thin to print satisfactorily; but, though many, myself among the number, believe that improvement results from such treatment, others strenuously deny any advantage. It is many years since the idea first struck me to apply direct measurements to the printing gradations of various papers, but the more I thought about the matter the more I became impressed with the magnitude of the task and the inutility of only half doing the thing. The accounts of Messrs. Hurter & Driffield's researches, and even of the experiments reported in his paper before the Convention by Mr. W. K. Burton, only prove that I was right, though, what a single individual ma}' not do, photographers collectively might very well undertake, especially as in the case of positive paper the require- ments in the matter of apparatus are not so great as for the more sensitive negative films, nor is the task one of such intricacy. In the case of all print-out films, for instance, we are spared the complications surrounding development as distinguished from exposure, while, with developed prints, in all probability the same laws established by Messrs. Hurter & Driffield would be found to hold. In fact, the work might be confined entirely to a study of the relative gradations pro- duced upon papers of different kinds, and by light of varying strength. For this purpose it would be necessary to establish a scale of grada- tions representing those of a " perfect " negative — if there be such a thing — but at any rate a scale of some sort by which to compare results ; and here again Messrs. Hurter & Driffield have already supplied us with the necessary data upon which to proceed in constructing such a scale, as well as the details of its construction, for which I would refer to the two diagrams given in connexion with their Convention article in last issue. Although no detailed descrip- tion is given, the diagrams, T think, sufficiently explain the principle, which may, of course, be modified in a variety of ways to suit cir- cumstances. The apparatus there figured is intended for the exposure of plates to the light of the standard candle, but for use in connexion with paper, and almost necessarily to daylight, a different and much simpler arrangement will suffice. Such a one I constructed some years ago consists of a printing frame or dark slide, with closed front, in which a revolving disc, similar to that in Messrs. Hurter & Driffield's diagram, is fitted, the motive power being a driving wheel and band, attached to the instrument after the manner of a chromo- trope slide. The disc is arranged to carry movable masks, having openings representing different series of gradation, so that either the general sensitiveness of the sensitive film may be tested or its capa- bility of rendering gradations, either coarse or delicate. The im- portance of this power of varying the character of the gradation is more important in the case of paper than of films. With such an arrangement it is only necessary to place strips of the papers to be tested or compared side by side in the prmting-frame portion of the apparatus, and to cause the disc to revolve for a given time, orjuntil a given depth of tint is obtained, as the case may be, when not only the relative sensitiveness but also the relative power of rendering gradations will be shown at a glance. Absolute sensitive- ness is of no importance in such an experiment ; if it be required, of course a standard light will have to be chosen, and this is rather more- difficult for slow exposures on paper than for negative work. Such an apparatus might be constructed and put on the market at a very small cost, and would prove useful in a variety of wavs in connexion not only with papers but with negatives, but more especi- ally would it assist the amateur in selecting the best paper to suit his general style of negative. \V. B. Bolton, CONVENTION NOTES.— II. What a blessing it is that Plymouth is not nearer to London than 216 miles ! If it were, we tremble to think of the inunda- tion of its streets and surroundings by the metropolitan photo- grapher, who would invade the place in shoals. In the history of Convention outings, there is no one place which can offer, in its immediate vicinity, so many delightful scenes for camera work as can Plymouth. Contrasted with Edinburgh, the town of Plymouth has so few- objects of quaint historical interest as to be nowhere in affordino- food for the camera of the archxologist ; but, unlike Edinburgh, one has only to take a comparatively short walk to reach Sutton Pool— the whilom harbour of Plymouth. This Creek of the Catte- water was formerly protected by having a chain stretched every night across its entrance. In this vicinity the Barbican, with its innumerable fishing boats and other shipping, affords excellent themes on which to practise with either the stand or the hand camera, and during Convention week it was difficult to walk many paces in this locality without running agwnst one or the other of these. It is, however, outside of the town wherein lies the great value of Plymouth to the photographic tourist. It would be difficult to find a more enchanting place for an excursion than the river Yealm (pro- nounced indifferently Yem or Yam). On the second day of the Con- vention the kindness of the local Clubs in providing a steamer enabled some seventy or eighty members to visit this river, the entrance to- which is two or three miles outside of the Breakwater, an artificial, strongly built erection which stretches well across Plymouth Sound for more than a thousand feet, and protects its shipping inside from the heavy ocean waves. No sooner, however, had the steamer got inside the Yealm, and realised the placidity of its waters compared with the turbulence of those outside, than rain began to fall, and, although soon this was accompanied by lightning and thunder, it failed to damp the spirits of the excursionists, who, well sheltered from the storm, beheld with admiration the beautiful stream with its romantic turnings and richly wooded banks. Had there come a gUmpse of sunshine, if but for a minute, many mementoes of that visit would have been carried away, for there were over sixty cameras on board, and their owners were only too anxious to have a shot at such scenery, but the Fates did not so will it. Having cast anchor, advantage was taken of a stay of over an hour to have a lunch, of which it is enough to say that, in excellence and variety, it surpassed all that could have been expected at any well-appointed hotel on shore. We do not know what local arrangements exist for visiting the Yealm, but our advice to all artistic tourists who find themselves in Plymouth is not to return without seeing this river, and selecting for their visit a day on which there are neither rain nor thunder- storms. Returning to Plymouth via the Mount Edgcumbe end of the Breakwater, and being thus afforded an opportunity of seeing the grounds of thi.-i far-famed place, which we may remark, par parent /lese, are generously thrown open to the public by the Earl of Mount Edgcumbe, we picked up a few who could not, either from business arrangements or anticipated mal-de-mer, take part in the forenoon excursion, and proceeded up the Tamar, the mouth of which is con- tiguous to the town. Here let us pause for a moment to say how July 28, 1893] THE BRITISH JOURNAL OF PHOTOGRAPHY. 477 much the excursionists owe to Colonel Birrington Baker for hi4 assiduous attention throusjhout the day. His intimate acquaintance •with the Royal Navy, witli which he is officially connected, enabled him to impart valuable and interesting information respecting the numerous war ships through which we threaded our way up tlie Hamoaze. A temporary cessation of the rain permitted of several exposures being made at some of these ships, and of Brunei's master- piece, the Royal Albert Bridge, wliich at Saltash connects Devon with Cornwall. Much rain fell during the passage up the Tamar but towards evening, after tea, the weather cleared, although too late for much good work. If tb.e weather was unpropitious on the occasion of the Tuesday's excursion, ample amends were made on that of Thursday. At a moderately early hour a very large party left Plymouth bv" train for Totnes. The town was en fife, and the sun shone brightly. After witnessing local processions in honour of tfie marriage, we embarked on a steam launch in waiting on the Dart to convoy the party to the pretty town of Dartmouth at the mouth of the river. The launch proving totally inadequate for the accommodation of the lai-ga party, a second boat of like dimensions was provided and also filled the surplus finding accommodation in a third boat. These were taken in tow by the launch, and a merrier party was never seen on the Dart. When a few miles down still another boat, with a small contini'ent ■which had preceded the main party, was seen waiting for us in the middle of the river, and it, too, was taken in tow to swell the goodly pro- cession, wliich, when we reached Dartmouth, must have presented a singular, if not a semi-formidable, appearance. What numerous pic- tures may be obtained here ! But to secure them one must go alone or, at any rate, with a much less numerous party than constitutes a Convention outing. On the boat nothing but hand cameras could be used for sheer lack of room in which to erect a stand, but on shore and with stand cameras, pictures will be found everywhere, lyin" as thick as the proverbial blackberries. Plymouth and the adjacent towns have given many good men to the world. Mention has already been made of Robert Hunt. He was one of the early investigators into the photographic properties of several substances. We owe to him the knowledge, inter alia of the developing powers of ferrous sulphate. He was the earliest and most competent historian of things photographic that we have had. His Hfsearc/ies on Light is a classical work ; so, for that matter is his Poetry of Science, together with other equally charming works. His memory will always be green in the recollection of all photographers •worthy of the name. To Plymouth also we owe such early Fellows of the Royal Society as Joseph Glanville and Dr. Yoiige ; such painters as Sir Joshua Reynolds, Sir Charles Eastlake, James North- cote, Benjamin Robert Haydon, Samuel Prout, Samuel Cook, and others. In fine, in mathematics, surgery, horology, electricity engineering, and literature, Plymouth, -with its immediate surround- ings, has produced many gifted and eminent men. In naming some men of mark belonging to Plymouth, we must not omit special mention of J. T. Towson, subsequently Marine Examiner at the Sailors' Home at Liverpool, and the discoverer of Great Circle sailing. He was early engaged in prosecuting photographic experi- ments, and in 18 j8-1», along with Robert Hunt, 11. Fox Talbot, and Sir John Ilerschel, was probably the only one so engaged. Dissatisfied •with the slowness of the achromatic lenses of that period, he wrote a paper, •which appeared in the London mid Edinburgh Philosophical Magazine for November, 18:jO, on the proper way to focus for Daguerreotyping witli simple lenses, in •ft-hich he pointed out the difficulty of using the common achromatic lens, the luminous focus being different from the chemical. Towson was also instrumental in preventing the success of Talbot's application for a patent for photo- graphing on glass: for, in 1838, he (Towson) had produced a photo- graph on glass which, with the k-nowledge of Hunt, he had sent to Ilerschel at the time. This was referred to by both as a proof that Mr. Talbot had no claim to an exclusive enjoyment of the privilege of producing photographs on glass. TELE-PHOTOGRAPHIC SYSTEMS OF MODERATE AMPLinCATIONS. If the positive element of a tele-photographic system have a large angular aperture or a high intensity, say /-."i or/-4, it i» possible to produce a combination of considerable magnification (in a short compass), maintaining at the same time sufficient rapidity for all ordinary purposes. With such a positive element, however, it becomes necessary to introduce a means of correction for spherical aberration when the compound system is used for any but one exten- sion of camera and one particular distance of object. The advantages of this type of lens have already been described, as also the manner in which the necessary corrections referred to have been carried out. Now, if the positive element have only a moderate intensity, say /-8 or less, and the magnification required be not great — in other words, if the focus of the negative element combined with it to form the tele-photographic system is not too small a fractional part of the focus of the positive element — the compactness of the tele-photo- graphic system i.< maintained ; and, further, the amount of spherical aberration introduced for planes other than that for which it is con- structed Ijecouies a negligible quantity. Again, with a comparatively weak negative, the latter can be made of considerable diameter, so that there is the compensating advantage of a greater angle than it is possible to include as against the loss of magnification. I was at first inclined to think that a special construction involving comparatively weak magnification in ordinary lenses of the rapid rectilinear type was unnecessary, as most cameras, for a given size of plate, will permit of sufficient extension to utilise one combination only of the doublet designed to coyer that plate, and so obtain an image of double the linear dimensions. Further consideration, how- ever, has led me to think that there are advantages of sufficient weight to merit a special construction. The chief disadvantage of using one- half of a doublet is that it requires stopping down in order to cover tlie plate properly, and, a^ain, there are, of course, only the two definite focal lengths possible with the one lens, i.e., both combina- tions or one alone. By the use of a negative attachment to the doublet lens the full aperture can be maintained, and a wide range of foci can be obtained by the employment of one negative lens only, in conjunction with it. controlled only by the separation of the nodal planes of the two elements (but in practice by the camera extension). Moreover, the one positive lens, used in conjunction •with a battery of several negative lenses each of different foci, can be made to give any focus one chooses longer than that of the positive used alone, and to include any less amount of angle that one may choose. After careful investigation I recommend that the rapid rectilinear type of lens (/-8, or even f-7) should be combined with a negative lens of half its focus, to form a really useful tele-photographic system. (If the negative is less than half the focus of the positive, there is danger of introducing outstanding aberration for any but one exten- sion of camera, and for other than parallel rays ; this aberration is only removed by stopping down the positive lens, reducing both angle included and rapidity.) Negative lenses, in this proportion of foci, can be made of larger diameter than lenses of the positive element, and a considerable angle can be included, and necessarily greater equality of illumination is attained than when the negative lens is of smaller diameter than the positive. With the proportion of foci recommended, the attachment to the positive lens is not inconveniently bulky. Weaker negative lenses can also safely be employed, or, in other words, the focus of the negative lens may be more than half that of the positive ; in this case the attachment is shorter, the magni- fication less, but the angle included greater. The figure illustrates the combination of a six-inch focus rapid rectilinear combined with a three-inch focus n^ative combination. When the foci are known, it is only necessary to know, or set the separation of the nodal planes N, K, to completely determine the equivalent focus and back focus {i.e., tlie distance of negative lens to screen). If / and f^ represent the foci of the positive and negative lenses respectively, a the separation, F the equivalent focus, and £F the back focus, then the following simple numerical formula) give the required information : — for the case in the illustration ; 6x3 18 24 3J + 3-6 } 3(6-3?) _6j *^=3| + 3-6 J "'' 4- 478 THE BKITISH JOURNAL OF PHOTOGRAPHY. [July 28, 1893 Kule I.— To FIND THR Equivat-knt Focus of the combination : Multipli/ the foci of the two elements together and divide the result by the sum of the focus of the negative lens and the separatioti, after Imoing fubtracted the focus of the positive lens from this sum. Kule II.— To FIND THE liACK Focus : Multiply the focus of the neqatiie lens by the difference between the focus of the positive lens and the separation, and divide the result (as in the last case) by the sum of the fvcits of the negative lens and the separation, after having sub- tracted the focus of the positive lens from this mm. [Note the importance of the separation as affecting the equivalent and back foci. If, instead of makinf? the separation 3|", we had chosen J of an inch more— t.e.,4"— the equivalent focus of the lens would be 18", and the back focus 0" only ; and if, on the other hand, we had made the separation ^ of an inch less, or 3|", the equivalent focus becomes 36", and the back focus 15". If the sum of the focus of the negative lens and the separation is equal to or less than the focus of the positive lens, then no focus is formed.] It is interesting to examine the capabilities of combinations by the above rules, and thereby to determine for one's self the suitability of the ratio that must exist between the foci of positive and negative lenses for any particular purpose. The separation between the nodal planes of the two elements is easily written for this purpose, but in practice is more difficultly measured. The object of this paper is to place the matter in the simplest light focus for a given extension of camera, the next step is to find the in- tensity of the tele-photographic combination. This is measured by the clear aperture of the positive element divided by the equivalent focus, as in all cases. The intensity values or their equivalents are now always marked upon the diaphragm notation of positive lenses, so that the intensity of the compound system is most readily deter- mined by reference to the intensity of the positive system and the magnification. It is expressed thus : — Calling /the intensity of posi- tive lens and M the magnification as before. Intensity of system = — in the particular type of case illustrated; I 1 Intensity = = _- In the actual example illustrated, the intensity of the rapid rectili- near is /-7, and the intensity of the tele-photographic system /-28, for the particular extension. [Note. — With less magnification and less camera extension, the in- tensity increases.] Rule v.— To FIND THE INTENSITY for a given extension of camera when magnification is known : Divide the intensity of positive lens by the magnification. I TIlBiUmeyer fqurvALEH Qe^sJI^EQENTfTQa jlj^NGE To^CTEEM \2 k ijrucus. of LoNs 2+ "( (E) pofl^bk, And happily there is a simple means of setting to work with- out any fear of mistake as to the conditions under which the instru- ment is used. It rests on the determination of the magnification of the image as compared to the positive lens ttsed alone. Calling M the magnification, v the back focus, wai/^ the focus of the negative lens : — M = l + v_ in the particular case M-- -I- So that, calling F the equivalent focus and / the focus of positive lens as before, F=fM = 4x0" =2i" as illustrated in the diagram. Rule lit.— To Find thr Magnification for any chosen extension of camera : Divide the distance from negative lens to screen by the focus of the negative lens, and add one. Rule IV.— to Find the Equivalent Focus of the combination for any chosen extension of camera : Multiply the focus of the positive lens by the mngnification. Having readily determined the magnification, as also equivalent Simple rules camiot, unfortunately, be given for the remaining two data that should be known to fully determine the capacity of the lens system — viz., the plate that can be covered and the extreme angle in- cluded— but the formulae to obtain them are readilv used. I give them applied to the case illustrated. (1) To DKTKBMINE THE DIAMETEB OP THE PLATE COVERED : — Calling D the diameter of the plate, a the full aperture of positive lens 5", "^ „ „ negative lens }", and V, as before, the back focus, 9 ', p-C,4./-i-)'"'/''<"'.^(''x./'') /'[K/-/')xjf'] = (6 X 3)5x0x3x1x6x12 ^ 3[y X 3 X 6 X 3] 113* = 13x t±^ 3x4.5 900 00 = 10-1" Thus it appears that with an extension of 9" from negative lens to screen, a circle of 10" is covered at full aperture — nearly sufficient to cover a " whole plate." In the diagram I have indicated the lens as covering only the diagonal of a 5x4 plate, but it will be seen that half of the whole pencil incident upon the front of the positive lens is received by the extreme margin of this plate. To find the covering power for any smaller stop inserted in the positive lens, it is only necessary to measure its diameter and substitute its value in place of a in the formula given. July 28, 1893] THE BRITISH JOURNAL OF PHOTOGRAPHY. 479 (2) ThK EXTRRMK ANOr.R INCLUDED BY THS COMBINATION is given by the following formula: — Calling a the angle, and F the equivalent focus, as before, rt = 2tan-'^ = 2 tan-' ^V- = 2 tan'l -210416 48 From the table of natural tangents we find tan 11° 63" = •21043, and hence the extreme angle that can be included is 24° nearly. When the lens is used to its utmost limits, it will be found that the angle included is approximately a constant for any extension of camera, i.e., with a fixed aperture of the positive element. It may be well to point out, in reference to the diagram, that a back focus (measured from the negative lens to screen) of only 5* is really necessary to cover the plate indicated (viz., 5x4) if full aperture be used. To work the matter out practically, we have for this a back focus of 5i". The magnification itf = 1 + ^ =2-8, and the equivalent focus JP=ilfx/=2-8x6=17". ,.. .nJxVx3+4xex(V+3) = (^ ^^> 3[yx3 + 18] ■ 12.51 _ 139 "'^'^ 24x69"^ ^^8x23 = -— ^ =6*4, the diagonal of a 6 x 4 plate. ooo Further the angle taken in is — 2 tan-i^i,2 tan-i-|^ = 2 tan-i -1882. ixF 34 And, from table of natural tangents, tanJO° 40' = -1883, and thus the angle included is 21° nearly. I have given a formula for the distance from ihejkmge to focussing screen in ray paper before the Society of Arts (published March 3rd of this year), but have not given it here, as the "back focus" ismost readily measured, and this measurement, as already pointed out, is the simplest cue to all further information that is desired or necessary. 1 hope that the very unpopular " formulae" contained in this paper may not detract from its interest to the ordinary reader, for the formulae are readily inter^rreted by any one with a knowledge of arithmetic. In conclusion, I may add that the effect of the form of negative lens adopted is one that tends, by its moderate power, to flatten the field of ordinary aplanatic lenses without introducing '_' reverse " curvature ; it minimises tlie tendency, in tele-photographic systems generally, to introduce pincushion distortion, it eliminates the violent chromatic fringes brought about by negative lenses of the double concave type, and diminishes the astigmatic aberration in the eccentrical pencils. T. R. Dallmuykb, F.R.A.S. • ♦ CONTINENTAL NOTES AND NEWS. Clearlngr ITeg-atives Developed in Impure T^ater. — M. E. Forestier, in L' Amateur Photographe, says that the quality of the water used in making up developing solutions is not always irre- proachable, which causes the lights and half-tones of a negative to have their transparency degraded. In order to remove this veil, he recommends that the plate, after fixing and washing, should be im- mersed in a solution of — Water 1000 c.c. Oxalate of iron 20 grammes. Alum 80 „ Thia clears the negative, which should then be well washed. The Fluorides of Sodium and FotasBlum for Strip- ping' Purposes. — These two salts, which are prepared by saturat- ing commercial hydrofluoric acid with sodium or potassium carbonate, take the form of white crystals, easily soluble in water, and present no danger in bandUng them, while they form excellent substitutes for hydrofluoric acid, which requires to be used with ccnsiderable precaution. The alkaline fluorides in the presence of an energetic acid, such as sulphuric acid, set free hydrofluoric acid, the alkaline sulphate being formed at the same time. Taking advantage of this reaction to produce a trace of hydrofluoric in a film of gelatine attached to a glass plate, the gelatine will be found to leave ita support with as gieat facility as if hydrofluoric acid were employed. To produce the minute quantity of hydrofluoric acid necessary for the operation, M. L. Mathet says he first places the plate in a solution of alkaline fluoride, leaving it therein for three or four minutes, then, without washing, immerses it in a ten per cent, sulphuric acid solu- tion, when the film will soon commence to regularly detach. He suggests that the plan would be available for cleaning off old negatives. In order to prevent the film, when detached, from expand- ing, the negative, before being stripped, should be soaked for about an hour in a five or six per cent, solution of chrome alum, being afterwards washed in several changes of water before the application of the fluoride and sulphuric acid. The Bollingr Water Seducer.— A writer iil a contem- porary advises the immersion of over-toned prints [presumably albumen, although it is not stated] in boiling water until they have toned back sufiiciently. The prints are then placed in cold water. Toluol IlXatt Varnish. — Toluol is a product of the distilla- tion of coal, from which it is obtained at a temperature of between 100° and 130° C. It is analogous to benzine. According to Lainer the foUowing formula with toluol gives a good matt varnish : — Ether 100 c.c, Sandarac 100 gr. Toluol • • 3.50 to 400 c. The powdered sandarac is dissolved by agitation in the ether, and, after filtration, the toluol is added. The varnish is employed in the usual manner. Photog-raphy without lilgrht.— Captain Colson states that in a picture on albumen paper of a bronze object, such as a coin, can be obtained by moistening the paper and placing the coin in contact with the surface, a reduction of silver takes place, and in a few minutes an impression similar to that producible by light is obtained, which may be toned and fixed. Flexible CHass.— The following is the formula given by Science lUustrie for a flexible substance as transparent as glass. DIssqIvo four to eight parts of pyroxyline in alcohol and ether in the propor- tion of a one per cent, solution. Then add two to four per cent, of oil of rice or any other non-siccative oil, and four to ten per cent, of resin or Canada balsam. Coat a plate of glass, and dry in a warm current of air at 60° C. This will give a sheet of a durable, unbreak- able, transparent substance, impervious to acids and alkalies, and less inflammable than ordinary collodion, and of any desired thickness or colour. With zinc oxide it has the appearance of artificial ivory. A "Very Rapid Collodion Process. — Having experi- mented with Dr. Hill Norris's process, which was patented some four years ago, without obtaining satisfactory results, M. P. David, of the Service d'Identification de la Prefecture de Police, Paris, has introduced some modifications of his own, and gives the following method of preparing a dry-collodion plate of a sensitiveness about 22° or 2.3° Warnerke. He coats a plate, 180 x 240 cm., with 2-5 ex. of collodion, containing eighteen grammes of silver nitrate and seven to eight grains of pyroxyline per litre. The film being set, the nitrate is bromised in a bath of Potassium bromide 80 to 120 grammes. „ iodide 0 01 „ Gelatine 2 „ Distilled water 1000 c.c 480 THE BlilllSH JOURNAL OF PHOTOGRAPHY. [July 28, 1893 Sensitiveness is obtained by immersing the plate for a greater or less time in a solution of Potassium bromide 18 to 25 grammes. Gelatine 1 „ Distilled water 1000 c.c. The sensitiveness increases ■with the temperature of the bath. At 70-75° the plate is left in for about two hours, at 90-95° for one hour. The figures are, however, approximate. The plate is then washed and dried. Contrary to what might have been supposed, says M. David, the collodion film does not show any tendency to leave the support even at a temperature of 100° C, provided that the surface of the glass has been carefully prepared. mo more Double Exposures. — For the modest sum of three francs a Bavarian gentleman undertakes to impart particulars of a method whereby the amateur may discover whether a plate has been exposed or not, and this without impairing the original quality of the plate. They should render impossible the oft-aceomplished feat of " securing thirteen pictures on a -dozen plates." The catchpenny trade is always with us, it seems, even in photography. ■ Black tones in X*erro-prussiate prints. — A contempo- rary says that ferro-prussiate prints acquire black tones by treatment with a solution of silver nitrate followed by development with iron oxSilate. The print fixed and washed as usual is placed in a solution (if silver nitrate, in which it is left until it has bleached, when it is placed in the developing solution. If, after development, it is placed in a solution of hypo, the black tone will tend to disappear, passing back to the blue stage. Thus, with a little care, a print may be obtained, in which the deep shadows are black, while the half-tones are blue. PHOTOGRAPHIC INDUSTRIES. The Lastehn-sude Pactort or F. York & SoK. It was our privilege, on returning home from the Photographic Conven- tion at Plymouth, to be permitted to break the journey to visit a very important photographic industry, of which a brief account will interest our readers. Very few there are who are not more or less intimately acquainted with the lantern slides, either individually or in series, so well and so long associated with the name of P. York & Son, of Netting Hill, London ; but it is not equally well known that these slides are produced in the town of Bridgwater, Somersetshire, for here is situated that factory from which emanate in hundreds of thousands those little gems of art whose function j[t isto delight, instruct, and amuse. ^ It is no figure of speech to say that more slides are issued from the offices and distributing centre of this firm at 67, Lancaster-road, London, than from any other centre of operations in the world ; and even several years ago, when writing some notes of a visit to this distributing centre of the firm, we spoke of their negatives and output as being measurable by the ton weight ; but since that time these have been very greatly in- creased. Some years have now elapsed since, with a sentimental regard for his native town, Mr. P. York decided upon selecting it as his place of manufacture. Under the guidance of the veteran chief, whose wonted energy does not seem in the slightest degree to be impaired, and his resident local manager, we have been privileged to inspect the whole of the Bridgwater factory and witness the various operations there carried on. Mr. York himself was, nay, still is, a great traveller, and, when he visits scenes or towns either at home or abroad, he rarely terminates his visit without carrying away with him negatives representing every salient feature of the locality thus visited, whether such be in the West India Islands, Monte Carlo, and other Italian towns, or even places of equal or greater merit, although of less distinction at home, such as those selected for Convention meetings. His camera and his aim are true ; he selects his subjects by instinct, and, whUe having a pardonable love for the civic palaces now to be found in every town of any pretensions, still he is not averse to " Loiter by the peasant's cot, And pot it with unerring shot." The Bridgwater factory occupies two houses in a quiei street, with out-honses erected in their gardens behind. We first visited the negative room. This is a fireproof structure, strongly built and slightly isolated from the other buildings. Humanly speaking, there seems no chance of the valuable contents sustaining damage from fire. These are arranged in boxes on shelves around the walls, the numbers on each corresponding with those in the catalogue of negatives in the possession of Mr. King, the manager ; so that, when an order from any subject is received by letter or telegram from headquarters, he can, by referring to his negative catalogue, lay his band at once upon the package in which the required negative is contained, and to which it is immediately returned when done with. The only kind of glass used is Chance's Crown, which York & Son find to possess certain advantages over others in respect of brilliance of surface, flatness and freedom from certain defects, which, although small to the eye, are visible in a marked manner when the picture is shown on a scale of great magnification on a fifteen or twenty foot screen. Tlie negatives in most cases are taken on 5x4 plates and, as we have said, there are many thousands of these in stock, for during the twenty- five years that this busmess has been carried on the number has been ever constantly increasing. The process of reproduction is wet collodion, which is supplied mainly by two makers if we judge of this by the enormous number of large labelled bottles we saw in a repository of " dead men." The transparencies are all taken on plates seven and a half inches square, this being of the best quality supplied by Chance Brothers, of Soho, Birmingham, and already alluded to. Of this glass thirty gross per month are regularly supplied. There are four transparencies printed on each plate. There are three dark rooms in which the plates are coated and developed. These, when coated, are sent by a lift into the room above, where they are exposed in cameras which point upwards to the sky. But, as even Somerset skies often vary in their brightness, the exposers above are in verbal communication with the developers below, who occasionally call out to give so many seconds less or more exposure to the next lot according as the light gets brighter or grows more dull. In the exposing room are four cameras with repeating backs, which slide both vertically and horizontally, and they are adjusted so as not to necessitate focussing. After exposure the plates are sent down for development and subsequent treatment. When the rush of work or the darkness of the weather necessitates it recourse is had to artificial light. This consists of a kerosene lamp as a source of illumination, the light from which is concentrated upon the negative by a five-inch compound condenser, and is then transmitted through an objective to the sensitive plate, an average exposure of twenty seconds being given. As there are quite a number of these copying lanterns, the firm is rendered independent of the weather, seeing that work may be carried on by night as well as by day. The developer employed is a ferrous-sulphate one, so prepared as to give the utmost clearness and gradation with purity of the whites. After being fixed in hyposulphite of soda, the transparencies— of which, as stated, there are four on the plate— are toned. It is no secret that a solution of a salt of platinum is the toning agent employed by York & Son. Seeing that platinum behaves in a whimsical and unreliable manner in the hands of many, bleaching in some cases and giving an exceedingly heavy and black image in others, investigations were long ago gone into by the firm, the result of which is that the platinum toning bath now and for some years employed is stable and reliable, its erratic tendencies being eliminated. In this lies the chief secret of the uniform tone, which is such a characteristic of York's slides that they can be distinguished from most others at a glance. The platinum toning also confers such stability, that we are not aware of any case of fading of the image ever having been known to occur with these slides. Varnishing follows toning, the varnish being a colourless spirit one. The system adopted in severing the plate, which is seven and a half inches square, ensures identity in the four transparencies impressed thereon. After a considerable pUe has been prepared, the examiner then takes them in hand, and unceremoniously rejects every transparency on which there is the shghtest blemish, or which in any respect falls short of what in his estimation a transpareilcy Ought to be. Owing to the experience of the workpeople and the card taken throughout, the number rejected is but few, and these, after having had the films stripped off and being cleaned, are employed as cover glasses. Concerning the mounting, it is not necessary we should describe it further than to say that starch paste is invariably used as the monntant. When gum is employed, it is found that, sooner or later, it ceases to adhere to the glass and leaves it. Each picture has its title printed in small type on a slip of paper, wliich is pasted on the edge of tjie finished elide. This is convenient fer reference when a quantity are packed in July i8, 1893] THE BRITISH JO&KNAL OF PHOTOGRAPHY. 481 grooved boxes, as the subjects are thus known without the necessity of withdrawing them for inspection being experienced. It is also useful in selecting and arranging subjects for lectures or miscellaneous entertainments. Some of the rooms are devoted to silver printing, and there is also a largo carpenter's shop on the premises, for, a^i may be readily sapposed, the packing and sending away of goods forms uo inconsiderable item in the day's work of a busy establishment like this. We have said that the factory is in Bridgwater, and may incidentally observe that the river on which this toy/a is situated is the only one which supplies the material out of which " Bath " bricks (so called from the name of the oriRinator of the industry of that well-known domestic article) are formed. Kach tide deposits a larije quantity of the sand suitable for the purpose for a mile above and a mile below the town. Beyond these extremes the deposit is either too (inc or two granular for tills industry. The liner deposits are, however, utilised in America and elsewhere in the manufacture of sapolio and iiudred soaps. Keturning for a moment to York's lantern-slido factory, there were twenty-six hands employed at the time of our visit. PHOTOGRAPHIC CONVENTION OF THE UNITED KINGDOM.* The following paper was taken as read: — AXASTIGMATIC APLANATISM AND THE ZEISS ANASTIGMATIC LENSES. By Dr. Paul Eudolph (Jena). [Translated from the Gerniau MS, 1 TirE anastigmatic lenses of Zeiss made their first appearance scarcely two years ago ; nevertheless, they have attracted the general attention of the photographic world, and, despite considerable adverse criticism, proved a great success. It would, therefore, be interesting to examine the special features to which these new objectives owe their popularity. Over 7000 lenses have now been sold, and though there are still many professional photographers and amateurs who have not had an opportuity of testing the powers of the anastigmatic lenses from personal experience, it may be assumed that nearly every one has heard of them or has seen photographs produced by them. The Zeiss anastigmatic lenses are well adapted for portraits and groups, for copying aud enlarging, for interiors and flashhght exposures, and for outdoor instantaaeous photography, for architecture, landscape, and photogrammetric work. Experts unanimously pronounce the Zeiss anastigmatic lenses to be superior to the older objectives, and praise their extensive range of applicability. We may refer to the respective writing.^ of Koster, Faber, Wallon, Eder, Vogel, and others. The following remarks are based upon the criticism of these experts, and, in particular, upon a paper read by me in March, 1892, in the Free Photographic Association of Berlin.* The Zeiss anastigmatic lenses are dissymetrical doublets, consisting of an achromatic anterior part whose ./?fn« has the higher refractive index, and an achromatic posterior part in whicli the crown has the higher refractive index. These two cemented parts of tlie doublet possess, there- fore, opposite differences of refractiveness in the crown and flint glasses employed for achromatisation.r This embodies the important principle by wiich it became possible to effect anastigmatic aplauatism of a system of lenses corrected spherically and chromatically for large apertures. The series of new glasses produced about six years ago by the glass works of Messrs. Schott & Co. , of Jena, rendered it possible to practically realise this principle in the construction of the Zeiss anastigmatic lenses. Let Jij, He, «j be the refractive indices of a certain glass corresponding to Frauuhofer'8 lines, F, C, and D, then the ratio ~'^° represents the «j 1 relative dispersion for the interval C-F. With the older series of glasses this value increased in a measure as the refractive index increased, e.ij., Crown of na = l-5166 had -"'■^ = 001643. ... . ."d - 1 Flint of /Id = 1-6129 had ^""^ = 002708. fid - 1 In order that the anastigmats may be constructed, it is, however • Photca/-. Wochenhlatt, Berlin, 1892, Nos. 18 to 21. t "Crown '■ and " Flint " are here placed in opiwitiou. not with reiipeot to their chemical composition, bnt are considered with respect to their optical ■provtrtkt. The same ?las3 may, therefore, appear in two different achromatic combinationi as lenses, either as " Crown " or " Flint " (oide Eder's Jal.rl,., 1891, p. 221., Eem ). In the following remarks " Crown g\ass" is always nnderatood to 'rotor to .that ghiss ot a binary lens, which is less in ralattce dispersion, while the term " Flint glass" referii to that glass which has the greater rdatite dispersire power. EelativB dispersion is the value represented by the expression ^, ^in being the diflorenca of the refractive J. • m-l ndioes for two lines of the spectrum, as a refraotire fedex wiUua thea* limits. necessary a range of glasses in which any given refractive index may be coupled with any desired dispersion. This postulate is realised, e.g., by the following glasses made by Messrs. Schott +n were respectively made to repre- sent ab'^cisso^ and ordinates, the points so represented formed a fairly straight line inclined to the axis (trid« Dr. J. Czapski, "Optical Lenses," ZdUchrijl f'ur Imtrtt. mcntenliiiuit'. Berlin, 1886, pp. 344 and 315) ; n was, therefore, a lineikr fnnction of n = o-l-C A n 4 482 THE BRITISH JOORNAL OF PHOTOGRAPHy. [July 28, 1893 Arrange in one plane (6g. 2), along the radii of concentric circles, bright discs. The angles between the radii should be chosen according to the astigmatic aberrations and the focus of the objective. Direct the axis of the objective at right angles towards the centre of the system of radially grouped discs, and focus one of extra-axial discs. The image obtained at the shorter distance of the focussing screen from the objective is, as fig. 3 shows, a portion of a radial line which, in proportion to the curvature of the image plane, becomes more and more indistinct towards either side, and is more or less interrupted r»diaUy in proportion to the degree of astigmatic deviation. Fig. 4 is an image obtained by focuseing a disc on a circle, situated midway between the axis and.the outside circle. It will be seen that images of all the discs grouped along the same curcle are of the same degree of distinctness or indistinctness, and also ex- hibit the same amount of distortion. Focussing at the greater distance of the screen shows the object (fig. 2) tangentially distorted. The image becomes thus composed of a series of circles concentric to the centre of the image, which are more or less f IG. 2. Fia. 3. Fia. 4. interrupted, or perfectly nnintermpted. The discs grouped along another circle, which had not been sharply focussed, are similarly distorted, though in a less marked degree. If, now, a screen having drawn upon it concentric to the axis of the objective circles and radii be substituted for the system of discs, the astigmatic objective would reproduce the original with partial similarity, but both systems of lines could not simultaneously be delineated with the same position of the screen. The shorter distance would yield sharpness of the radial elements, the circles at the same time being badly defined ; the longer distance would show the circles sharply, and at the same time the radial elements badly defined. A sufficiently large screen bearing the two systems of lines, radial and concentric circular lines, appears thus to form the most natural test for astigmatism. Such a screen would, however, be too uniform and too little adapted for exhaustive tests. The screen of 2 x 2 metre area, as it is used in the photographic laboratory of Carl Zeiss of Jena, is for this reason arranged somewhat differently, and it may not be uninteresting to here give a short descrip- tion of it. Upon strips of paper of 18 x 21 in area two systems crossing each other at right angles of parallel lines of varying thickness, and placed at varying distances from each other, and the strips themselves are fixed to the screen with one of their ends at the centre of the screen, and their sides parallel to the sides of the screen in such a manner that in each strip the radial and tangential lines alternate. The middle of the screen contains a field consisting of rectangular cross lines, which is intended for testing sharpness of definition. The tangential parallels form substitutes for the system of concentric circles, while the ratlial parallel lines take the place of the radii proceeding from the centre. The difference between the two positions of the focussing screen for sharp delineation of the marginal portions of the systems of straight lines represents the astigmatic difference. For the purpose of demonstrating the incorrectness of the image caused by astigmatism, the screen has square fields of more or less fine rectangular cross lines diagonally attached to it in such a manner that in one case the system of lines is parallel and at right angles respectively to the diagonal, while in the other cifse they are inclined at 45° to the diagonal. Tlie screen has also samples of writing and printing attached to it. When focussing square cross lines at the edge of the image, the astig- matic objective produced in the two characteristic cases furnished by the test screen the following deformations : — 1. The straight lines composing the net at the edge of the image are parallel and at right angles respectively to the direction of the radial lines. In this case— represented by fig. 5, in which A is the point of inter- section of the axis of the objective and the plane of the object. A' that of the axis and the plane of the image— sharp focussing of the tangential lines causes the lines which are at right angles to the radius to appear nearly sharp, while the lines which are parallel to the radius are almost entirely invisible (image a). Focussing of the radial lines produces the converse of the last test. The lines parallel to the radius appear sharp, the lines at light angles to it disappear (image t). Mean focussing re- sults in a totally ill-defined image, and eventually in more or less marked reversion of the cross lines, »sfich as a black net in a white field. 2. The straight lines of the net are inclined at 4.5° to the radial direc- tion. In fig. (J let A and A' again be the point of intersection of the ob- jective axis with the plane of the object and image respectively. Tan- gential focussing causes the rectangular cross lines to be distorted so as to present the appearance of tangentially elongated hexagons, and, in the Tib. 5. Fig. 6. ease of great astigmatic difference, it may result in almost precise com- mutation of the cross lines into a single system of tangential line* (image a, fig. 0). It we focus between these two limits, the net may, similarly as above, eventually be reversed so as to appear as black points in a white field ^ the same effect may also be produced in anastigmatic images by unsharp focussing. Similar results of a more or less marked character may be obtained by replacing the quadratic net by one formed of oblongs, rhombi, circles, &c. In order that these relations might be objectively fixed, photographs were taken in the photographic laboratory of the optical works of Carl Zeiss of the test screen, and the photographs so obtained were reproduced by photo-lithography. There are four plates, of which we show the two most characteristic ones, Nos. I. and IV. (shown). Here an " aplanat " and "anastigmat" are subjected to direct comparison Plate I. has been taken with an " aplanat," made by a renowned firm. The objective had a focal distance of 14 cm. and a relative aper- ture of 1-G, and was stopped down to /-12-5. Image and object are in the ratio of 75 to 1000, and the angle subtended by the object is about 67°. The centre of the screen is sharply focussed. In this part the delineation is extremely good, a sufficient proof that the objective, per se, was a good specimen of its kind. As the margin is approached, the definition, however, loses more and more in distinctness, and astigmatic distortion increases more and more. While the tangential lines are fairly sharp up to the edge, the radial lines rapidly decrease in definition past the third field. In the diagonal squares, the bounding lines of which are at right angles and parallel respectively to the radius, it will be noticed that the tangential lines are markedly sharper than the radial lines, the latter being almost invisible, and in the squares, whose sides are incUned at 45° to the radial direction, the distortion at the margin of the tangential lines may readUy be observed. The squares appear, in fact, as hexagons. Plate IV. has been taken with a Zeiss anastigmat, viz, anastigmat 1-6-3, 14 cm. focus, all other conditions being the same as those existing in the former case. There, too, the centre was accurately focussed ; but barely any traces of those details which point to astigmatic imperfections of the margin of the image will be noticed. Plates II. and III., which are not shown here, were taken with the July 2?, 189S] THE BRITISH JOUKNAL OF PHOTOGRAPHY. 483 !iame " aplanat " as that nsed for Plate I. Id the first case tbe taaRential marginal lines were focussed, in the second case the marKiiial radial linea formed the critical part of the object. While in the former caae the centre appeared to be fairly sharp, in the latter case it was totally i worthless. The characteristics of astigmatism, as above explainedi become apparent in botli plates. ■ The older types of lenses (aplanatic, antiplanats, portrait lenses, single lenses, Ac), admitted of astigmatic correction, but they could not at the same time be corrected for Hatness of field. The Zeiss " anastigmat " ■was the first lens in which, as we pointed out, anastigmatic aplanatiam I was combined with the realisation of other requisites of a good photo- graphic lens. A lens having anastigmatic curvature yields sharply defined points from centre to margin. These cannot, however, simultaneously be filed upon the plane negative plate of the photographic apparatus whenever the points constituting the object are nearly in one plane at right angles to the axis, or when they are at a relatively great distance from the objective. , If it be desired to simultaneously fix these shari) points upon the plate, it would be necessary to use a curved sensitive surface corresponding to the curvature of the image. Clearly the use of such curved sensitive strata is impossible, for it must not be forgotten that for each lens type, each focal length, and even each degree of magnification or reduction, there is a distinct corresponding curvature, to say nothing of the practical inconvenience attaching to curved photographic plates. At present we are, at any rate, limited to flat negative plates. From an optical point of view, this is an undesirable limitation, which seriously affects definition and depth of the curved image. The flat plate must be covered nearly uniformly sharply from centre to edge, unless the objects are grouped ob a curved surface corresponding to the curvature of the image. With portrait groups photographers had a means of compensating the anomaly by arranging the persons in a semi- circle, in the centre of which the objective is placed. With landscape and instantaneous photographs, however, such an expedient is only rarely, if at all, applicable. In order to obtain tolerable distinctness in the image from centre to edge, it would be necessary to work with narrow angles or to stop the lenses down considerably. In working in this manner, it must be borne in mind that both in the centre and at the edge near and far objects are to be depicted simul- taneously ; the objective yielding a curved image causes, however, on the photographic plate distinct objects to appear indistinct, and sufliciently near objects sharp at the edge when the focussing is sharp for the centre. On the oblong flat negative plate, ABCD (fig. 7), let near objects be depicted at AB, distant objects at CD; then, if the centre, M, be accurately focussed, the points of sharp delineation are situated upon a curve, and are represented by E, which intersects AB in two points, and is sym- metrical with respect to AB. By stopping the lens down we obtain, as is well known, greater depth for distant objects than when focussing for near objects. In the present case the depth nesessarily diminishes, therefore, from the centre to the margin. The limits may be graphically represented by curves, Ti and T„, which, being symmetrical with respect to E, have their greatest distance apart at M. The depth of focus is represented by the area contained between T, and T,. By this area the imperfections of the marginal image may readily be ascertained. When it is important to improve the distinctness at the edge, it would be necessary to sharply focus a point situated at a distance from the centre, and to sacrifice the distinctness at the centre. The deficient depth of focus of lens yielding a curved image does, nnder certain conditions, not become apparent in street scenes. In such cases it may happen that the position of the camera is such that the rows of houses are delineated simultaneously on both sides, of the street, the distant houses being thus shown in the centre, the near ones at the edges of the plate. In such a case the curvature of the image may even become the very cause of greater marginal distinotnesg than is obtainable with the flat field. With all other, and nearly always existing, cases distant objects have to be shown simultaneously at centre and edge, and in such cases it is absolutely necessary to have a flat field. It is possible to partly flatten the field of the aplanat. This is moat conveniently done with those points of the image which are dne to the meridional rays, i.e., for the tangential directions in the image. Under these circumstances, one would, however, have to abandon the anastig- matic correction of the image, and to rest content with partial distinct- ness. Those points of the image which are due to rays contained in a sagittal section yield another image surface (image points of radial direc- tions), which touches the former surface in the axis of the objective, and deviates from it with continuous curvature towards the edge, as already explained. With angloi o( 50' this deviation amounts to one-fifteenth ; with 70", to one-sixth ; and to 0O\ even nearly one-third of the focal length of tbe lens. The section o( these image surfaces by a plane passing through the axis of the lens would present the appearance shown in fig. ». Curve a appertains to tbe image points in the meridional section (tangential di.Htortion), b to those of the sagittal section (radial distortion). Ho re- presentu the axis of the lens U„ a principal ray. This result may te obtained with aplanatic lenses if their halves be sufliciently widely separated. The marginal distinctness is then very Fiu. 9. defective, and the stopping down has to be carried very far if it is at all desired to obtain sharp definition at the edge or fair definition extending over a considerable field. An objective having an anastigmatically flat field, such as the '• anastigmat " produces, however, a sharp image upon the flat plate, which, as fig. 9 shows, is bounded by lines T,, T,., the latter being parallel to the focussing line E. This objective delineates near and distant objects with the desired uniform sharpness and centre at edge. The Zeiss anastigmats yield, therefore, a uniform depth of focus from centre to margin without necessitating the same amount of stopping down that is imperative with the " aplanats." The anastigmats have in propor- tion to their covering power a considerably relative rapidity. A paper read by the author in the Free Photographic Association at Berlin was accompanied by two instantaneous photographs reproduced by the lithographic process, which served for comparing the "anastigmat" with a normally corrected " aplanat." The two lenses used in the tests had the same maximum aperture, and were stopped down to 1-9. The anastigmat 1-6-3, /=21 cm., gave a circle of 25i cm. diameter of fair definition (624°), while with the aplanat 1-6 of 20 cm. focus stopped down to -1-9 the same circle of 11 cm. at most (31°). The aplanat,* which was the make of a renowned firm, was in itself a good specimen, the definition being excellent in the centre. In order to obtain with the aplanat a sharp image of the same extension it would have been necessary to stop the lens down to about /-36, and thus to seriously diminish its rapidity. Professor Roster, of Florence, who, in his own interest, subjected the anastigmats to exhaustive practical tests, found that the anastigmats, vrith a given angle, admit of five to eight times more rapid exposures than aplanats and antiplanats of best make. Dr. ChiusoU, of Ravenna, speaks equally favourably of the anastigmats, and Professor Fabre, of Toulouse, writes, in his Aide-memoire of 1891, " The anastigmat is eleven times more rapid than the comparable objec- tives of older types." The author himself compared an anastigmat 1-6 -3/= 170 mm., with an excellent specimen of the aplanat 1-9,/^ 145 mm., and found that the anastigmat covered the test screen of Zeiss with almost the same depree of definition that could be obtained with the aplanat working at/-32, i.e., the anastigmat working at 1-0-3 with a ticelre times greater rapidity than the aplanat 1-9 was found to do the same as the latter. Owing to the better concentration of light in the anastigmatic flat image, as compared with the anastigmatic curved or astigmatic flat image, with an objective of the former type, the intensity necessarily diminishes lessirom centre to edge than a lens belonging to either of the last-named types. This advantage of the Zeiss anastigmats cannot be overrated, as the oblique incidence of rays at the edge of the image is, in itself, productive of a continuous diminution of intensity towards the edge. The anastigmats yield a negative which is uniformly exposed from centre to margin. The advantages resulting from the anastigmatic flatness of field greatly ex- tend the range of applicability of these lenses. The advantage of being permitted to use a large stop when a certain size of plate is piescribed, and the advantage of the uniformly bright • By " aplanat" we understand the wollknown type of symmetrical doobleU of four len-^es introduced by Steinheil. Prerioua to the invention of the anartigmats, it was the best t^-pe, and afpeared in the market under many names, such as apUant. enryaeope, rectilinear, symmetrical, lynceinoacope, paraptanat, *c. 484 THE BRITISH JOURNAL OF PHOTOGRAPHY. fJuly 28, 1893 field, assists in the solution of the problem of nsing short focus lenses for relatively large plates; i.e., with a given rapidity of the objective, essen- tially shorter foci may be used in the case of anastigmatic lenses than is admissible with other types, e.f/., anastigmat l-0'3 (Series II.), of a focus of 105 to 120 mm. is quite sufficient for sharply covering a plate 9 x 12 cm. (3J X 5 inches) at /-9 ; with the older types, the focus would have to be 120 mm. (7i inches) at least. In order to cover 13 x 18 cm. (5x7 inches) at /-9, it was necessary to employ a lens of, say, 350 mm. (14 inches) focus, whereas, with the anastigmats, this result may be obtained with a focus of .210 mm. (SJiaches), and even with 170 mm. (7 inches). Short foci give; ho'Weve;^,.,-j^':6(juaiidistancea-oi the object,. a.better depth than long foci ; they yield a'sbjutjger image of objects situated atdiffp-ent distances^ from' the position- crf'''TOe apparatus. The anastigmatic lenses have, therefore, in Vanother sen^e, greater depth of focus than the older lenses. '■''■'.'■ , These advantages- become, particularly apparent in instantaneous and wide-angle lenses,' and in' the photography of architecture and interiors, and in copying. De,tectiye cameras may be made of smaller dimensions, as they may be fitted with short-focus lenses. Photographs of architec- ture and interiors, and reproductions of maps and paintings, may be taken by means of rapid lenses, i.e., at short exposures. The tables published by the author in Edcr's Jahrbuclt, of 1893, in his paper on " The Astigmatism of Photographic Lenses," which are based upon calculation, show the extent to which anastigmatic flatness has been obtained with the various series of the anastigmats. Table I. Mean Deviations of Image Curvature for Objectives at 100 mm. Focus. Objectives. Deviations for Inclinations o£ a Principal Ray of— 10% 15-. 20". 2*'. 30-. • 35'. 40'. Anastigm 1-18 mm. mm. mm. mm. mm. mm. (Long foci) ... -0-2 -0-4 -0-5 -0-2 •fO-3 — Anastigm 1-9 -0-5 -0-9 -1-2 -1-0 -0-6 -fO-4 -1-2-4 -Anastigm l-6'3 ... -0-3 -0-5 -0-6 -0-3 -(-0-8 -f2-4 Anastigm 1-12-5 ... -0-G -11 -1-4 -1-4 -1-0 -fO-2 Anastigm 1-4-5 ... -0-5 -1-0 -M -1-5 -0-6 -(-1-3 Anastigm 1-7-2 ... -0-7 -1-2 -1-8 -1-2 -0-2 + 30 Anastigm 1-18 (Short foci) ... -0-9 -1-4 -1-9 -2-2 -2-2 -1-4 -fO-4 Aplanat 1-7 -0-2 -0-6 -0-9 -0-8 + 0.2 -I-30 — TaiSle IL Astigmatic Differences for Objectives at 100 mm. Focns. Objectives. Deviations for Inclinations of a Principal Kay of - . 10% 15'. 20°. 25'. mm. 30". 35'. 40'. mm. mm. mm. mm. mm. Anastigm 1-18 ... -0-1 -0-1 -0-2 -hO-1 + 0-6 + 1-0 -fS-O Anastigm 1-9 0- -hO-05 -fO-o -fO-3 + 0-6 - 0-0 -4-0 Anastigm 1-12-5 ... -fO-1 -fO-2 -fO-4 •fl-3 + 2-2 -^ 3-0 Anastigm 1-6-3 ... -fO-1 -hO-4 -fl-2 -f2-2 + 3-6 + 4-2 Anastigm 1-4-5 ... -i-0-2 -i-0-6 -)-l-5 -f3-0 + 5-3 -f 9-0 Anastigm 1-7-2 ... -fO-2 -t-O-5 -I-1-4 + 2-S + 5-5 -i-n-0 _ Aplanat 1-7... ■..-. -t-o-s- ■i-2-0 -^4•o + 7-0 ■)-12-2 -I-19-4 — Table I. shows the deviations of the mean curvature of the various anastigmats for every interval of 5\ The table gives also the correspond- ing value for an aplanat of relative aperture 1-7, as it may be interesting to directly compare the correction of this hitherto best type of lenses with the Zeiss anastigmats. Table II. gives the astigmatic deviations. The figures are reduced to a focus of 100 mm. These two tables suffice to give an adequate idea of the correction of the anastigmats. Studying them more closely, we find that the long- focus lenses at the series 1-18, the typical copying lenses, are at the head of the t&ble. In computing these lenses, the greatest possible pains were taken to render anastigmatic flatness as perfectly as possible without in the least neglecting accurate spherical correction. The greatest deviation of tjie mere curvature in an objective of I'OO mm. focus of this type, with an inclination of a principal ray of 30°, i.e., with a field of 60° is 05 mm., and the astigmatism 06 mm., amounts which may be practically neglected. Next to this type comes the anastigmat 1-9, which, up to 70° of field (35° inclination of ,1 a principal ray), has a maximum deviation of curva- ture of 1-2 mm. and a maximum astigmatic differerence of 0-5 mm. After these come the shorter focus lenses of anastigmat 1-18, ana- stigmats 1-6-3, 1-12-5, 1-4-5, and 1-72. The aplanat 1-7 has up to 30° a deviation of curvature of about 1 mm., while with the' more rapid anastigmat, 1-6-3, it is only 0-6 mm. The former has 12-2 mm. astigmatic difference, the latter only 36 mm., i.e., less than one-third of that amount. The difference is still greater with wider angles. In conclusion, the other advantages which the Zeiss anastigmats com- bine with anastigmatic flatness may be shortly enumerated. They are the following : — 1. The reflection images have a most favourable position. 2. They admit of the most colourless glasses being used, and 3. The two parts of the doublet are in close proximity. The images formed by jeflection at the boundary surfaces between glass and air are all at a considerable distance from the plane of the image. By this means the appearance of fogged images, which generally in- creases with the number of isolated lenses, is reduced to a minimum, and thereby the image rendered exceedingly brilliant. The existence of this property is amply proved by photographs taken with the anastigmatic lenses. None of the anastigmatic lenses can be shown to have a fiare-spct,- even when dazzling light enters the objective. The use of colourless glasses is an advantage which cannot be over- rated. Apart from sensitive plates, this is the only means of satisfying the universal postulate, depth of drjinition u-ith short exposures. ■ With objectives of the same type, a certain desired amount of depth can, with a given focal length, only be obtained by corresponding stop- ping down of the lens. The further, however, this stopping down is carried, the less becomes the light which can pass through the lens. If, in addition to this, the scanty light thus admitted is further impaired by detrimental colouring in the glasses, as was the case with the glasses formerly used in the construction of aplanats, it becomes naturally im- possible to work at short exposures. The anastigmats, when applied to outdoor photography at /-18 give fully exposed negatives, the usual commercial instantaneous dry plates being used. Before the application of the Sehott baryta glasses to the construction of photographic lenses, this belonged to the province of impossibilities. Even with Btops/-25 and/-36 instantaneous photographs are still obtainable. The short structure of the anastigmats favours the diminution of the rapidity with ichich the intcnsii;/ dccreasei from centn to edije. It diminishes that part of the decrease of the intensity wliich is caused by partial stopping of these obliij-ae pencils by the edges of the lenses. Let Ly and L„ (tig. 10) be the lenses forming a doublet of a diameter 2'D, let B be the plane of the diaphragm, and let the diaphragm be Fia. 10. situated midway between L, and L„. Let a he the distance of the diaphragm from the apex of the anterior surface, and let 2 (i be the diameter of the aperture of the diaphragm. If for the sake of simplification the collective effect of the parts of the- doublet be neglected, i.e., if it be assumed that the diameter of the pencil passmg through tlie diaphragm 2 d is also 2 d previous to the passage through the lens, and also if we disregard the curvature of the external surfaces and the thicknesses of the lenses, then the oblique pencil pass- ing through 2 d is stopped in that particular moment when the principal ray, H, is of that degree of obliquity which is represented by a straight line contained in a plane passing through the axis of the objective, and connecting the edge of the lens with the diaphragm edge on the same July 28, 18»3] THE imiTISII JOURNAL OF PriOTOGRAPHY. 4*5 , ' side of the axis. Let tbe angle between this principal ray, H, and the lis be etitioners would resjieotively submit to your Honourable House that the existing New Zealand Customs Taritfis not calculated to foster colonial excrflence in photography, or to prevent the introduction and sale by itinerants of cheaply produced articles, to the discouragement of the investment of capital in improved photographic apparatus and materials by qualified members ot the profession permanently resident in the colony. 4. Your petitioners would therefore pray your Honourable House to abolish the ad valorem duty on im- ported photographic materials ; to permit bromide, chloride, and platinum papers the same privilege of free entry granted to albumen papers ; to enact that persons practising photography in New Zealand as a profession, and particularly all itinerants engaged in the art or in the sale of photographic pictures, should be subject to registration and a licence fee, and all imported photographic pictures of New Zealand scenery and photographic enlargements be subject to a protective duty of not less than twenty-five per cent. And your petitioners will ever pray," &c. RECENT PATENTS. PATENTS COMPLETED. Improvements is or cosinbctbd wpth Doublet Lesises fob Photographic- P(.-RP0SE.S. No. 23,378. Cabl Paul Goerz, 7a, Haupstrasse, Schijneberg, and Emil Von HoEHH, 60, Prinzregentstrasse, Wilmersdorf, Berlin, Germany. — June ft, 1893. Cub invention relates to doublet lenses for photographic purposes, and is illustrated in the sectional views (figs. 1, 2, and 3 of the accompanying drawing). Within the last few years, as the result of the labours of the scientific glass- 486 THE BKITISH JOURNAL OF PHOTOGRAPHY. [July 28, 1893 laboratory in Jena, there have been made available for optical industries new kinds of glass, which by reason of their optical properties, differing from those of the kinds of glass which alone were previously to be obtained, have given rise to improvements in optical instruments, and especially in photographic objectives. Tlie conditions of the elimination of tlie astigmatic errors of pencils of rays entering oblii^uely require that the crown glass should be of a refractive power higher than that of the flint glass combined with it. Varieties of glass which render combinations of this kind possible have been regularly manu- factured since 1886, and since that time attempts have been made in various quarters to utilise the new kinds of glass for the elimination of the astigmatic error in photographic objectives. Thus, for instance, amongst others, the " anastigmat " of Hartnack, calculated by Dr. Miethe, was introduced in the year 1887. This objective is free from astigmatism when the image is approxi- mately plane ; but, like all other objectives manufactured by various opticians upon the same principle, it has tlie disadvantage that the spherical error cannot be eliminated, and hence the system has an illuminating power too feeble for most of the needs of practical photography, and is especially ill adapted for instantaneous exposures. The reason for this fact is that in order that, the spherical error may be com- pensated for, the refractive power of the crown glass must of necessity be lower than that of the flint glass which is combined with it. The construction of an "anastigmat" of good illuminating power, with the spherical error ■corrected, that is to say, without injury to the sharpness of the image, thus appears to be prevented by the interposition of two incompatible conditions, standing in opposition to each other, and, as a matter of fact, it has been customary in the best-informed scientific circles for a long time to consider it impracticable to devise a method of construction which should combine the two properties above referred to. Dr. P. Rudolph, of Jena, the inventor of the recently introduced "an- astigmat" of Zeiss, forming the subject of a German patent, No. 56,109, was the first who succeeded in bringing forward proof of the possibility of constructing " anastigmats " of good illuminating power. We have endeavoured to gain greater approximation to the ideal form by a method difl'ering essentially from that adopted by Dr. Rudolph. For this purpose we have made extensive calculations, directed at first to the single object of determining whether, as a fundamental principle of a new objective, the astigmatic error could be reduced as far as possible, in the expectation, which appeared, humanly considered, to be justifiable, that, even if it should prove to be impossible to eliminate the astigmatic error absolutely, it might yet be hoped to effect important improvements in the direction indicated. Starting from the above-mentioned facts, well established theoretically, in accordance with wkich a crown glass of lower refractive power than that of the flint glass combined with it must be used to eliminate the spherical error, and a crown glass of higlier refractive power than the flint glass component for the elimination of the astigmatic error, it was sought to determine, by strict calculation, how far a doublet, each half of which was built up of three lenses, would be able to fulfil the conditions required for the elimination of the two aberrations, the spherical and the astigmatic. The separate components of such a system might, with reference to the result, be conceived to be so made up that they should consist either of a negative flint glass {b, fig. 1), enclosed ny./. between two positive crown glasses, a and a\ in such a way that one of the two latter, say a, should have a higher refractive index, and the other, say ai, a lower refractive index, than that of the enclosed flint glass, b, or be made up of two negative flint glasses, b, Ji (fig. 2), enclosing a crown glass, a, 17^.2. in which case one of the two flint glasses, say b, should have a refractive index higher, and the other, say 6', lower than that of the enclosed positive crown glass, a. r ■ ■ ■ ^ It was found to be possible in both metliods of construction, whilst compen- sating for the spherical and chromatic aberrations, not only to reduce tlie astigmatism, but to eliminate this last in a manner theoretically perfect. Of the two methods of construction under consideration, the latter (crown glass between two flint glasses) is found to involve unfavourable forms for the separate components, and the employment of such kinds of glass as have theii' practical applicability limited by disadvantageous peculiarities, so that the former combination (flint glass between two crown glasses) was exclusively adopted in the further working out of the problem, and the determination of the constants of an objective capable of being carried out in practice. As an example, there is depicted in fig. 3 of the appended drawing an objective of Fi^,3. the kind described, of an equivalent focal length of 240 mm., and a free aperture of 36 mm., of the natural size, and in axial section. The maximum efi'ective aperture is 30 mm., corresponding to one-eighth of the focal length. The constants required for the construction of the objective are as follows :— Thickness of Lenses, dl = d6 = 7-334 d2 = d5 = 1-833 d3 = d4 = 4-584 A (distance apart) = 11-00. nD nG Kind of Glass. Li = L« 1-61310 1-6-3B83 V = L-' 1-56804 1-58182 \? = L* 1-51497 1-5-2663 Radii of Curvature. Rl = - R8 = 45-835 R2 = - R7 = 54-324 R3 = - R6 = 19-853 R4 = - R5 = 49 088 All measurements, radii, thickness, distance, &o., are expressed in milli- metres ; the kinds of glass are designated by their exponents of refraction for the line D (uD) of the solar spectrum, and for the line Hg (NG') of the spectrum of hydrogen. If a principal ray, inclined at an angle of 30° to the axis, be calculated through the system, and the position upon it of the image point of the sagittal rays, and those of the meridional rays, be determined, a measure of the residual astigmatism is found in the distance of the two points. This distance amounts, in the case of the objective chosen as a specimen, to 1 -2 mm. when the image formed by the meridional rays is flat, and this residual amount of astigmatism has no greater unfavourable effect upon the sharpness of the image formed by the marginal rays than that caused by the secondary spherical aberration in the axis. The lens just referred to as an example, based upon strict calculation, is symmetrically constructed, but the combination of two absolutely identical halves is not to be regarded as a special characteristic of the objective system under consideration. The only characteristic mark of objectives of the new kind is rather the combination of separate systems independently corrected for spherical, chromatic, and astigmatic error, each made up of tliree lenses, the glass of these last having refractive indices properly graduated in the manner described ; indeed, one system of the objective might have an external foyn difl'ering from that of the other, or in the same objective one system might be built up as in fig. 1 and the other as in fig. 2. Any such modifica- tions may be undertaken by a calculating optician without difficulty ; but, from a practical standpoint, they are to be regarded as purposeless, since the more simple symmetrical form satisfies all the conditions herein taken into account to a suflicient extent. Furthemnre, since each of the two separate systems constitutes in itself an objective corrected for spherical, chromatic, and astigmatic errors, each may be employed alone as a simple photographic objective. Having now particularly described and ascertained the nature of our said invention, and iu what manner tlie same is to be performed, we declare that what we claim is : — 1. A photographic doublet, the two component systems of which are each corrected for spherical, chromatic, and astigmatic errors, being to this end made up of three lenses, as follows : — either (a) of a negative lens enclosed between two positive lenses, one of which ha.s a higher, and the other a lower, refractive index than the enclosed nega- tive lens, or (b) of a positive lens, enclosed between two negative lenses, of which one has a higher, and the other a lower, refractive index than that of the enclosed positive lens. 2. The employment of a single system of the kind described in chain I as an independent photographic objective, substantially as hereinbefore described. July -28, 1893] THE BRITISH JOURNAL OF PHOTOORArilV. 487 APPLICATIONS FOR PATENTS. Na 13,354.— "An Improved Frame or HoMer for Photographic Kilms and platea." S. D. Williams.— On(«fi yuiy 10, 1893. No. 13,373.— "Improved Mrans for regulating the Rays of Littht )uv>sing tlirouRh Pho'osraphic Lenses." Complete specification. J. W. Fawobtt.— /Mffrf yi(7y 10,' 1893. ^ MEETINGS OF SOCIETIES FOR NEXT WEEK. Date o( Meeting. Nam© oi Society. Pljice of Meeting. July 31 Asso. Studio. Nethergate, Dundet. BirminKham Photo. Society ... Club Room, Colonnaallmeyer tele-photo lena witfc bim, and, after waiting an hour and a half, found that the state of the atmo- sphere prevented him from using it. Mr. Fre.shwater a.sked if there was any advantage in usini; pink or maave albumenised sensitised paper over white ; He also ine latter, in tlie majority of instances, takes up the art as a fashionable pastime, and his name is legion. Some conespondents have said, in some instances, he is proud to give Jiis work away ; in others, to charge the cost of material, and often to make a profit for himself. In any case, the professional must sutler to some extent. We can quite imagine that, in many cases, amateurs of the present day, unlike those of old, have an idea of the £ .«. d. ■element, and do not give any improvements they may make so freely to the world as did their elder brethren. We find, on going through the specifications of patents in connexion with photography for the last few years, that by far the larger pro- portion of them are taken out, presumably, by amateurs, for it is rarely that the trade or profession of the applicant is described as " photographer." The patentees are of all manner , Excursion to Kadlet Leaves Moorgate-street, Midland Railway, by the nineteen minutes past two train for Raulett. 8, Composition. In the Liverpool District Registry of the Chancery Division, High Court of Justice, on the 8th ult., Messrs. Brown, Barnes, & Bell, photographers, of Liverpool, obtained a perpetual iiy unction restraining Mr. John Ashley, of 87, Bola-street, Liverpool, and Ormskirk, from .carrying on the business of a photographer under the style of Brown, Barnes, k. Bell, and from representing that the business he is now carrying on at Liverpool and Ormskirk is the business of the plaintiff, or in any other way a part or connected with it. 408 THE BEUTI3H JOURNAL OF PHOTOGRAPHY. [August 4, 189 Bristol In-termational Photographic Exhibition.— The Council of the Bristol and West of England Amateur Photographic Association announces the Triennial International Exhibition of photographs, apparatus, appliances, and processes to Ik held in the galleries of the Academy of Arts, Queen s-road, C ifton Bristol will be opened on Monday, December 18, 1893, contmuing open till Monday January 22, 1894. Apart from photographs for competition, the Council will 'esteem it a favour if those who have any interesting examples of the history and progress of photography will kindly lend them for exhibition. All pictures apparatus, and contributions of any kind will be insured at the expense of the Association. Especial care will be bestowed on the hanging, so that all pictures shall, as far as possible, be done justice to, to facilitate which the whole of the extensive galleries above referred to have been retained. Thirty-six medals, including one gold and twenty-one silver, are to be given. A fee of five and ten shillings, according to space, will be charged each exhibitor. Photooraphic Survey op Warwickshire.— On Monday there was opened to the public at the Birmingham Museum and Art Gallery an exceedingly valuable and interesting collection of photographs of Warwickshire landmarks and scenery. The exhioition is the result of the second year's work of the members undertaking the photographic survey now being systematically carried on under the auspices of the Birmingham Photographic Society. La5t year, it may be remembered, something like 700 pictures of old and famous buildings —some of them since swept away by the ruthless hand of the present-day "restorer" and speculative builder — were hung in the Art Gallery: and at the close of the exhibition, by a happy idea, they were presented to the Corpora- tion for preservation on behalf of the public. The present exhibition consists of nearly 500 photographs, and, at its close, these also will be presented to the Corporation. The survey, it may be explained, is being carried oq voluntarily by the members of the Birmingham Photographic Society, who at their own expense defray all the costs involved in the taking and preparation of the views. The cost of mounting, preparation of catalogue, &c., which is very considerable, is defrayed by the Warwickshire Survey Council (who also pro- vide the oak frames in which the photogi-aphs are publicly exhibited) by the help of subscriptions and donations. Leytosstone Camera Club. — August 5, Open Social Evening at Head- quarters, eight o'clock. 7 (Bank Holiday), Burnham-on-the-Crouch. Leader, Mr. A. E. Bailey. The Club will proceed by the train leaving Liverpool-street, G.E.R., twelve minutes past eight, calling at Stratford twenty-eight niinutes past eight, arriving at Burnham fifty-six minutes past nine The Club will also attend the Firemen's Fete and Competition on the Essex County Ground, Leyton (open all day). Ashton-under-L yne Photographic Society. -Excursion to Liverpool, 29th July, 189.3. — Considering a dark and drizzly morning, a goodly number attended, led by Mr. Chas. Lord, who had secured a permit to photograph on the docks, also a permit from the White Star Line to view and photograph the R.M.S. Majestic The ship had just been beautified, and those who had cameras soon had them in position, and secured rare and good pictures. After this a number of plates were exposed on ships, &c., amongst them being a good picture of one of H.M. Troopships. Over sixty plates were exposed. RECENT PATENTS. No. 13,808.— July 17, 1893, No. 14,604. — "Improvements in Frames for Photographs, Opalines, and other Pictures." P. Campbell.— Z)a(ec( Jubj 29, 1893. PATENTS COMPLETED. A New or I.mprovkd Proces.s and Combination of Materials kor the Treatment of Photographs previous to Colouring. APPLICATIONS FOR PATENTS. "An Improvement in Camera Cases." F. K Bussell.— Da/eaterf July 20, 1893. No. 14,074.— "Improvements in Apparatus for Taking Photographs on Sensitive Films or Plates." B. J. Edwards.— i/aied/u^y 20, 1893. No. 14,112.— "Improvements in Optical Lanterns." S. J. Levi and A J Jones.— Zioierf ./jtij/ 21, 1393. No. 14,163.— "An Automatic Changing Box for Photographic Films." W R. Baker,— IJaterf/itiy 22, 1893. No. 14,364. — "Improvements in Instruments for calculating Photographic Exposures.' Complete .specification. A. VfATKiss.— Dated July ^, 1893. No. 14,432.— "An Improved Focussing Appliance for Photographic Camera.'!." F. T. Y. TUmVETt.— Dated July 26, 1893. No. 6906. fi. M. Williams, 1, Camden-place, Bath, Somersetshire. July 1, 1893. My invention relates to a new or improved process in the treatment of photo- graphic prints, for iiii]iartiiig thereto a perfectly translucent enamelled or ivory surface, sufficiently brilliant to constitute a finislied picture, and which may, if desired, be tinted or coloured in an elaborate and most artistic manner by the application of suitable oil colours upon the back surface thereof, whereby the lighter or more delicate tints, as well as the heavier or more pronounced colours, appear with added brilliancy upon the face of the picture, and I intend that my said process shall be commercially known as " Mrs. L. M. Williams's Enamel Process." In carrying my invention into effect, I procure a sheet of perfectly clear glass, whicli I cleau with white wax, and edge the same with mucilage, gum, or other, preferably, transparent adhesive substance, the waxed portion or which may then be coated with collodion, and permitted to stand aside until perfectly dry, which, under ordinary conditions of temperature, will generally occupy about six hours, when a well-mixed solution of gelatine and glycerine, in equal jiarts or thereabouts, may be poured over the plate, and again placed aside until quite dry and hard. The surface of the glass thus prepared is then well wetted, and upon this is carefully placed (also wetted) the photographic print, with the albumenised side downwards, which, after being treated with the squeegee, is put aside and allowed to stand for about twelve hours, more or less, according to atmospheric conditions, at the expiration of which time, or any reisonable subsequent period, the whole is then immersed in a bath of hot molten wax, with a photographic j.rint uttermost, and allowed to there remain until the print becomes perfectly transp.arent, when it may be removed from the bath and placed aside until quite cold. I then remove the picture from the glass by carefully cutting around the gummed edges thereof with a sharp knife, and by the means of the same instrument I remove the glaze from the print, thereby leaving upon the picture a clean, bright ivory surface, of suflicient brilliancy to constitute a finished picture, which may then, if desired, be mounted and framed in the usual way. If the picture is to be tinted or coloured, I place this face downwards upon a sheet of perfectly dean glass, and retain it smoothly thereon by the ap- plication of mucilage, or its equivalent, at each corner, when, by reason of the perfect transparency of the picture (rendered so by the process through which it has passed) every detail of the print will be clearly read upon the back surface, and may then be painted in oil colours to any degree of artistic finish desired, and when quite dry the picture may be removed from the glass, when it will be found that the front of the print has a most beauti- fully enamelled ivory surface, and showing every detail of colour and tint that has been given upon the back surface, and with a brilliancy not attained by any system hitherto employed. The picture may then be mounted and framed in any m.anner desired. The claim is :— The herein-described process, and combination of materials, in the treatment of photographic prints, for imparting thereto a perfectly transparent enamelled ivory surface, which may or may not be afterwards coloured or tinted by the application of suitable oil colours to the back surface of same, substantially as herein described. HreettnsjS of SboctetiejEJ, MEETINGS OF SOCIETIES FOR NEXT WEEK. Date of Meeting. Name of Society. Auffust 8 ' Biriuinghaiii Photo. Society I, 8 Derby „ 8 (jreat Britain „ 8 Hackney „ 8 Mancheeter Amateur ^.. ,> 8 PaitOey ,t 8 Stockton I, 9 \ Leicester and Leicestershire „ i) ' Lt'ytonKtone M 9 1 Munster „ 9 ■■ Photographic Club II 9 , Houthport 9 Stockport Place of Meeting. 10 , 10 . 10 , 10 . 10 . 10 . 10 . 11 . 11 . 11 . 11 . 11 . 11 . 11 . 12 . Birkenhead Photo. Asso (ilossop Dale Hnll London and Provincial Mancheeter Photo. Society . North Kent Oldham Oarditf (Iroydon Microscopical Halifax Camera Club Ilolborn Ireland — Maidstone West London HuU Clnb Room, Colonnade Hotel. Smith's Restaurant, Victoria-st. 50, Great Rusaell-st. Kloomsbury. 206, Mare-street, Hackney. ' Lecture Hall, Athemeum, ! 9, Gauze-street, Paisley. ' Mason's Court, Hicrh-strcet. Mayor's Parlour, Old Town Hall. The Assembly Rooms, Hig-h-road. ! Scho')l of Art, NcUon-place, Cork. Anderton's Hotal, Fleet-street, K.C. ' The Studio, 15, Cambridg-e-arcade. I Mechanics' Institute, Stockport. j Y.M.C. A., Grango-rd., BirkenheaA ; 71, Prospect -street, HuU. Champion Hotel, 15, Aldersc|Ute.8t. 36, Geonre-stroet, Manchester. Graves end. The Lyceum, Union-street, Oldham. PublicHall,George-street,Croydon, Rooms, 15, Dawson-street, Dublin. "The Palace," Maidstone. Ohiswick School of A'*t. Chiswicfc. 71, Proapact-street, Hull, , . _. August 4, 1893] THE BRITISH JOURNAL OF PHOTOGRAPH Y. 400 LONDON AND PROVINCIAL PHOTOGRAPHIC ASSOCIATION. July 27, — Mr. A. Cowan in the clinir. Mr. J. CoLB said he was nuking a hand camera with o front which would ii: nv the len.i to be used ut the extreme edge of the plate. He promised to show the camera at a future meeting. Uranum Toning of Platinum Printh. Mr. J. S. Tb.m'E, in reference to his experiments in the uranium toning of jilatinura prints, referred to those in wliicli silver, if any present, had been removed, and said it hud been suggested that mercury might have remained, which wou d hive ncoountcd for the toning action. In a more recent experi- ment he had useil bichromate of potassium and hydrochloric acid as a means of reducing the silver, if there were any in the paper, to a state of chloride. The print was then washed and put in hypo, us tiefore, for twenty-five minutes. The print was cut in halves, and one half treated in the manner described ; then both halves were placed in the urauiiau toning solution for !ialf an hour, and the two halves toned to precisely tlie same colour. Mr. H. Haddon, on chemical grounds, could not understand the reducing action of platinum on potassium ferridcyanide. Less Cdstcmary Usks of Orthochromatism. Mr. W. Fi. Debenham showed two photographs of a violin. In one the inlaid brown wood was not visible, and neither he nor the possessor of the violin was satisfied with the result. He then prepared a dipped plate, which iie used with a deep yellow glass, with the result that a much better result was obtained, the detail being clearly visible. He used an ordinary Britannia plate, dipped in a bath of erythrosine, 1 : 10,000, tnr two minutes, and not washed before being allowed to dry. Ammonia was not necessary. He found that with purchased orthochromatic plates he could not get clearness. Mr. C. H. CoOKK agreed with Mr. Debenhaiu that dipped plates gave superior results. He always used a dipped plate when copying old silver prints. In reply to a question, Mr. Debknham said that with the dipped plate the exposure was very much jrrolonged, though he had forgotten to what extent. He used the coloured glass placed in an extemporised stop in front of the lens. He always used the stop in front of his portrait lenses. Mr. J. S. Teape said he could not get clear results on commercial ortho- chromatic plates. When using them he found a material sold by Christy &. Co. far superior to cherry or golden fabric, to answer well for dark-room illu- mination. He asked how long dipped plates would kee[). Several members thought they would keep for at least a fortnight. After farther discussion on orthochromatic plates, the meeting terminated. Amateur Photogriphic Aaaociation.— A Council Keeling, to award the prizes, was held .July 11, at 5S, Pall Mall, the RijUt Hon. the Lord de Ros in the chair.— The minutes of the last meeting having been read and confirmed, the following members were elected :—R. Oarlington, Esq., F.R.G.S., Lady Agnes Daltou Fitzgerald, Newton W. Eniraens, E^q., and James Gale, Esq., LL.D. Tlie following resolution was proposed by Mr. Milne, seconded by Mr. Howard, and passee done in the shaJe in a north light. He .•Lhowed a great number of specimens, principally of portraiture, on this paper, which gave splendid results. For portraits be recommended the mauve shade. Dealing with platinum, be de- monstrated the development of the cold-bath process, the ea«e of working which was generally acknowledged. He gave hints as to vignetting, showing masks made of zinc with serrated openings, which, he said, were more useful than those made from any other material, it being very pliable, and thus allowed the opening to be enlarged or otherwise with the greatest facility. An interesting discussion followed. Mr. H. Smith took first place for pictures at the London Colney outing. Northern Photographic and Scientific Association.— July 20, Mr. Robins (President) in the chair. — Mr. Coulter delivered a lecture on The Chemistry of the Dry /'tale. A considerable amount of discussion took place after the lecture was over, and eventually a hearty vote of thanks was accorded to Mr. Coulter, to which the latter gentleman made a suitable reply. Mr. CoOHiLL reported the result of the excursion to South Kensington Museum, and spoke in high terms of the kindness and courtesy extended to the members of the party by llr. George Murray, one of the Curators of the Botanical Section of the Museum. Mr. GooDHEW reported the result of the excursion to Battersea Park, and handed round some photographs he had taken in the subtropical gardens, which were very beautiful. He referred to the courtesy of those in charge of the park, who assisted the party in every possible way. At the excursion to White Webbs P.ark and Enfield no photographs were taken, as the weather was unpropitious. Dr. Atkinson and Mr. W. V. Haylett were elected auditors for the ensuing year. Five new members were enrolled. A class for beginners is in course of preparation, and those wishing to join are requested to send in their names at once to the Secretary, 32, Park-avenue, Wood- green, N. Hackney Photographic Society.— July 18, the President (Mr. Houghton) in the chair. — Various books were added to the library. Mr. Poli.akd showed and explained his reduction camera. Mr. Hexsler asked how to intensifya film which had had retouching medium on ? Mr. R. Beckett advised use of turps first to remove retouching medium, and proceeding in the adopted manner. Mr. Barnes asked the best way to develop an old plate ? The Hon. Secuktarv said, " Use less alkalL" Mr. T. H. S.M1TH asked what pro- portions of amidol should be used to develop- a much over-exposed Cadett plate.' Mr. Bkckett said, "Reduce the quantity of sulphite solution to quarter the quantity, four grains bromide, and double the amidol." The Hos. Secretary (Mr. W. Fentou Jones) then read a paper on exposure Tables anil Meters. He advised, before actual practice, overhauling camera, backs, dark room, to see if white light was perfectly excluded, and, when using lens, to cover up diaphragm slot. The sun's position had a great deal to do with time of exposure. Use as large a stop as possible consistent with good defining powers. Rain cleared the air, and many a good picture could be taken when raining. Would not advise judging by amount of light through diaphragm stops. Experience and judgiiient are best, but a talile or meter to start with is advisable. Exposure of bromide plates and papers are best tested by giving varying test exposures, and then according for future use. Plates wer« not always the speed they purported to be. Mr. Penny asked, " Was it best to use one table .and plate?" Mr. Hensler had used Watkin's, but not success- fully. Mr. MUXN h.id u.sed Hurter k Driffield's, saving himself a lot of plates. Mr. Hawkins asked about Cadett's developer being a quickener up of plates. Mr. W. Fknton Jones said he did not study the developer when exposing, and thought it erroneous. Would advise one plate and one table, and that of a simple kind. Mr. Avknt had used nearly every table in the market, and said that, whilst he had found them right around London, in the country they had given him wrong exposures. He was of the opinion, too, that a table .should be as much simplified as possible. JPLY 25, Mr. W. Houghton presiding. — Members' work vros shown from Messrs. Beckett, Guest, Nunn, and Roofe — Question by Mr. Fort: "What is the best varnish for films?" Reply: "Messrs, B. J. Edwards & Co. supply a good one, use cold." Mr. Hensler asked, "Should one aim at softness or contrast in statuary?" Reply: "Softness. Study the lighting. A dark background is generally used because it will per- mit of more contrast. The range of tone should show relief." Mr. Selfe showed a print in which the sun was sdarised , and a second reflection, due to one of the 500 THE BimiSH JOUKNAL OF PHOTOGRAPHY. [August 4, 1893 surfaces of the lens, appeared over the foreground of the print which was weak enough to escape reversal. Mr. Morgan then read a paper on Messrs. Hauffs metol and glycin. He said the class of work which suits amidol will also suit metol. The chief ditl'erence is that amidol requires no alkali, metol will tole- rate almost any amount— preferably potash carbonate. For bromide papers metol with three parts of their " A " developer to one of "B" will gives as good results as the best ferrous-oxalate ones in half the time and with half the ex- posure. Esperiments were mide under same circumstances. Thirty seconds proved correct for ferrous oxalate whilst only fifteen seconds for metol. After- wards seven half-plate negatives were developed in the same two ounces of metol developer and no difference in density could be detected amongst them. Metol will keep indefinitely. But only half the exposure necessary for pyro is sufficient lor metol ; this is essential. A plate was developed with metol, in eight seconds the image Hashed up strongly at once, but development was con- tmued till dense enough without fear of fog. Over-exposure gives flatness. Negatives and prints were shown, one three seconds with pyro, against one and a half seconds with metol ; the pyro one was hard and the metol one soft. The peculiar speciality for glycin is for black and white line subjects, it jnust be used on very dilute form, and its action is nearly automatic, as time will bring varied exposures to full density without its going beyond. For hand- caniera work either time or stop can be reduced to half. Generally develop a little deeper than that for pyro, as it prints quicker, because there is no stain and it loses little in fixing. Warm tones can be obtained by development, but it takes too long. Either amidol, metol, or glycin, developed plates can be toned, iutensihed, or reduced as others. Amidol will stand forcing better than metol. Brixton and Clapbam Camera Club. —July 18, the President (Dr. J. Reynolds, F.R.G.S. ) in the chair.— .4. member of the newly formed Committee of Instruction was present for the purpose of assisting less-experienced members in the more elementary principles of photography and answering questions relating thereto. The attendance of members showed the necessity lor forming such a committee, and it is believed that the result of such a step will be to strengthen the number of members of the Club to a considerable extent. This was the first attempt in the history of the Club to form such a committee, and at the meeting two nominations for membership and promises of others were given in. Mr. Baldwin-, of the Eastman Company, gave a very mteresting demonstration on Solio Paper, and toned several prints by the separate and combined baths with great success. Members were invited to comply with the request of the Photographic Society of Great Britain for a representative set of lantern slides and results of modifications of the several printing processes, and the meeting was then closed. The next meeting will be held on August 1, when Messrs. Fuerst Brothers will demonstrate the working of Amidol. South London Photoffrapliio Society.— .July 17, the President (-Mr. F. W. ijdwards) m tlie chair.— Messrs. Dicker and Tredray were elected members. 1 he evening was devoted to the discussion of methods of combination printing. 1 he following were suggested :— Draw round the outline of the object to be printed with a thick pen filled with Indian ink. When the ink is dry, block out the remainder of the negative with black varnish, .ind, when dry, print. 1 he printed image can now be covered with gambose or other non-actinic medium (which can be removed durincr washing), and the balance or such por- tion ot the picture as is required obtained from a second negative. Care must be taken to print both portions equally. If any white lines appear round any portion of the finished picture, these must be" filled in with colour care being taken to match the tint of the picture. Alternatively the second negative may have blocked out a portion of equal shape and size to that printed by the hrst negative. To print skies in pictures where there is not a large quantity of fine foliage against the sky, a print is made on silver paper, and the landscape portion is carefully cut off from the sky with a sharp pen- knife or scissors, and the two portions of the print allowed to discolour, and usea as masks, one being used to cover the landscape negative when the sky is being printed trom, the sky negative and the sky portion used when the land- scape portion is being printed. This must not be printed too deeply, or they will h.T,ve the appearance of being in advance of the landscape. The Piiesidbnt suggested stripping the negatives with cresco-fylma, and cutting out portions of tne stiipped hlms, and combining them on an old negative glass. By this method prints are obtainable by one printing, and a considerable saving of time eflected where a large number of prints are required. Liverpool Amateur Photographic Association.- July 27, Mr. William Tomkinson in the chair --The following gentlemen were elected members "f the Association :-Mr. Thomas A. Collinson, Rev. J. F. Anderson, and Mr SiT" ^•?":'T- ^^'- J' A- «'"'='»"• (Messrs. .Adams & Co., Charing Cros- Ind;dinrth?'m7"'Al''' ^'''''' ^^°'°r^'^^<' tP'"«l"i«« and nfvelti^s, Tde, ./ ,^^r •^'^'"°', '=''^n'e''». w'tl» swing back and rising front, the Ideal cameras (ordinary and twin lens). "Lightning" stand, pantosconeT aluSuS,ir ""''''' '•*'^J"^"""«" ^""'t^'-^. -^'"^ camera^ in brass S • ♦ jg^g FORTHCOMIXG EXHIBITIONS. Septembers *Roya! Cornwall Polytechnic Society, Falmouth. W. Brooks, Laurel Villa, Wray-park, Reigate. " -"-21 'Hove Camera Club. Hon. Secretary, H. Emery, 142, Church-road, Hove, Brighton. „ 25-NoT. 15... •Photographic Society of Great Britain, 5a, Pall Mall East, S.W. Assistant Secretary, R. CMld-Bayley 50, Great Russell-street, W.C. October 1-31 *Hamburg. Das Ausstellungs Committe dcs Amateur Photographen Verein, Schwanenwik, 33, Hamburg. •I 9-Nov. ... *Photographic Salon, Dudley Gallery, Piccadilly, W. Hon. Secretary of Organizing Committee, A. Maskell, 215, Shaftesbury-avenue, W.C. November 7-11 '"SoutV London Photographic Society. Hon. Secretary C. H. Odkden, 53, Melbourne-grove, Dulwich, S.E. ,, 20-25 »Leytonstone Camera Club. Hon. Secretary, A. El. Bailey, Rose Bank, South-west-road, Leytonstone. December *Madra8. The Hon. Secretary Amateur Photographic Society, Madras. - ' Signifies that there are open classes. C&rre^j^on'i^ntR RhonlH never :rrite on both sidp-s of the paper. No notice is tfUcen of comiriwiiicaUons unless the names and addresses of the writers are given. TELE-PHOTOGEAPHIC SYSTEMS FOE MODERATE AMPLIFICATIONS. To the Editor. SiK, — The appearance of an article on the above interesting subject, from the authority to whom we owe its introduction to the photographie public, leads me to think that you may perhaps find a corner in your Journal for the following items bearing on the matter. The methods here described for ascertaining the positions of lenses and screen, though differing from those in the article referred to, have the merit of being most sinaple, requiring no complicated calculation, and are likely there- fore, to commend themselves to those for whom equations have never I had much charm. Tliese methods are the result of studies of my own, I and I would not trouble you with them were it not for the fact that nothing similar to them has, to iny knowledge, yet appeared in any of the journals. f |»i ""Tl The first is a diagram, from which the operation of these systems of i lenses appears to me to be very clearly shown. In the accompanying figure, a h is the axis of the combination extended away towards the focussing screen. The positive lens at A has its focal plane at A; (I have taken for these examples lenses of the same focal length as those referred to in Mr. Dallmeyers paper, though, naturally, the system is applicable to any others that may be thought of, and set down the drawing to a quarter-inch scale). The negative element, B, of three- inches focus, is placed anywhere between A and A,, so that its focal plane, B,, may not cross that of A. In this example, the distance of B from \ is three and three-ijaarter inches. In speaking of the distance between the lenses, it i-> understood that the distance referred to is that between their nodal planes. Perpendiculars are drawn through the nodal point of B and through the focal plane of A at A,. At any dis- tance from A, a part A,C is taken in this fooil plane, representing the size A,C of an image formed by the positive lens alone. This measure- ment is purely an arbitrary one. but for convenience sake it should be small. From B,, through C, draw B,GD. me-iting BD in the point D. The distance BI> will now bear that proportion to A,C which the focal length of the combination bears to that of the positive lens alone — in this case twenty-foar to six, or an amplitication of four times. The position of the focus screen will be now showu by drawing a line, DE. through D and parallel to n h, and a line from B through C to meet it at a point E, which will then mark the distance from B at which the focus of the cambination will be found, in this case nins inches. It will be seen that, while the focal plane of A is stationary at A,, that ot B at B, follows every alteration of the position of E, and that a line through BjC will meet BD at a greater distance from the axis of the combination as B moves towards A, and at a nearer point to the axis as B is further re- moved from A. Therefore, if B be i)laced at any distance from A, with its focal plane always behind that of A,, by means of the lines drawn through C, its enlarging etiect upon an image produced by A alone, and from this the equivalent focus of the whole (that ot A being known), and the distance of the screen from the back lens can always be found. In any case the drawings should be carefully made to as large a scale as- possible. The method above described can be worked out for any combination of lenses, using, of course, the corresponding measurements, and result.-* arrived at in a ridiculously short time, once the simple plan is learnt, and the elYects of greater and less separation become so much clearer in a diagram than is possible in the case ot a mathematical calculation. August 4, 1895] THE BRITISH JOUHNAL OF PHOTOGRAPHY. «01 la the second method of calculation I take the focal lengths of the two elements, positive and negative, and multiply them together, placing the result as expressing a fraction, of which the focal length I desire to obtain is the divisor. This result, although apparently of no great value to the process as it representsthe distance between the focal planes A, and B„ in the diagram above ; but, as Mr. Dallmeyer points out, this factor is by no means an unimportant one, as it affects the rcsultti to as great an extent as the very foci of the lenses themselves. Having found this, the distance of separation of the positive and negative lenses is the difference between tlieir foci plus this fraction aforesaid. Then follows the last calculation which gives the focus inherent in the elements in their respective positions, and, by subtraction from the focal length required, tlio back focus or dis- tance from the back lens to the screen. Although apparently compli- cated, the last calculation is simply this : — The separation of the lenses is multiplied by the focus of the negative lens and divided by the fraction representing the separation of the focal planes, giving as a result the sum which is to be deducted from the equivalent focus decided upon to give the back focus or distance to the screen. Let ns calculate the combination referred to by Mr. Dallmeyer on this basis : — (1) 6" Pos. x3" Xeg. = 18-^24 equivalent focus required— J{ or J separation of focal planes. (2) 6" Pos. — 3 Neg. = 3 -I- J as above = 3J" separation nodal planes. (3) 3 J or ' - + ; (3 being the focus of negative lens) = " ^ | (separation of focal planes) = " + J = 15 deducted from 24" equivalent focus required gives 9 inches back focus. As the degree of enlargement and intensity of aperture can be so easily ascertained when the equivalent focus of the combination and its relation to the focus and aperture of the positive lens are known, these detailed are not referred to. It occurs to me that with a working intensity of /-Sin the positive lens, and four degrees of enlargement or /-32 in the combination, no great degree of rapidity can be expected, and that, when circumstances might demand it, a greater separation of the lenses and reduce! amplification would be desirable, conducing as they would to enlarging the available aperture, and gaining in rapidity — or are we to take it that definition is likely to be unsatisfactory if a larger aperture than /-32 be used. In the matter of the portability of several negative lenses of various foci to use with a single positive lens or combination, and give various degrees of enlargement, I fancy that, seeing that, in the case of a positive lens of six inches focus, these would recjuire to be all of a power higher than this, and necessarily, if of large diameter, as recommended, of appreciable weight, that the advantage will not be great enough to compensate for these dis- advantages, apart from the expense of such a battery of perfectly con- structed lenses, and the fact that the beauty of the tele-photographic combination is its power of giving pictures of any size at any distance from an object, subject only to conditions of actinic intensity and avail- able camera extension. Combinations of two negative lenses of dissimi- lar focus might be made so that they would give three ranges of power, or why not have interchangeable positive lenses with their correspond- ingly and necessarily modified lengths of tubing, for this latter condition would probably be required in the case of a variety of negative lenses. The same tube length would rarely do for two different lenses. I think that, rather than increase the already necessarily portly size of this useful adjunct to photography, the aim should be to reduce its size as much as possible. As the normal focus of a lens for parallel rays becomes so much increased when used for near objects, I do not recom- mend a great difference between the power of the positive and negative lenses, as this practically puts it out of the field when used under these circumstances. Where the distance between the nodal planes is small for distant objects, the lens is available for nearer ones without necessarily looking like an astronomical telescope, and every half-inch gained in portability is worth having. — I am, yours, &a., CardiiT, July 31, 1893. Chas. E. Hancock. EXPOSURE, DEVELOPMENT, A5D FOG. To the Editor. Sib, — I have just been reading your leader on the above subject, and, curiously enough, an experience which appears to me to bear directly on the phenomenon in question has just occurred to myself. Being out with a hand camera and a dozen special rapid plates, I exposed some half-dozen, and, knowing I should not expose any more for a time, I closed the safety shutter of my camera and walked on. After a time another opportunity occurred, and I exposed, as I thought at the time, two more plates, forgetting that the safety shutter was down, so that, in reality, these two plates received no exposure at all. t)u reaching home, I proceeded to develop my plates, and all went well, good negatives resulting, until I came to the two unexposed plates, which were treated exactly the same as the others, as I had not then found out the mistake I had made. The solution, pyro-soda, was poured on, the dish mstantly covered and set rocking; but, on looking to see how development was proceeding. I wa» surprised to find that, instead of the picture being just appewing,. the whole plate, rebate and all, was fogged all over, and thi« in » mncn less time than the first appearance of the image on a properly exposed plate. The second plate yielded precisely similar results. I was, of course, pu/.zled at first to account for this, but I soon recollected that I had forgotten to raise the safety shutter. The question still remained why the plates should have focrged all over w hen they bad never been exposed at all, and the probable solution seems to be as stated in your article, though in my case the plate seems to have broken down in less time than in the case referred to by you. It may probably be taken for granted that, the more rapid a plate is, the greater tendency it will have towards this particular result, aJtbongb undoubtedly some makes of plates may be more prone to it than others. I enclose for your inspection a film taken from one of the plates above referred to, also a print from a plate exposed on the same day and oat of the same box, from which you will-see that, whatever the true explana- tion may be, there is no manner of doubt whatever as to the facts. — I am, yours, *c., J, H. Baujock, F.C.S. Croydon, m amateobs and pbofessionals. To the Editob, Sib, — You have had letters from time to time complaining of the want of unity amongst professional photographers, also hinting at the alleged inactivity of the National Association of Professional Photographers of Great Britain and Ireland in not bringing about the said unity, and, curiously enough, chiefly from writers who have taken no visible part in. the work. I am writing to inform your correspondents and the profession generally that a meeting will be held at Anderton's Hotel, Fleet-street, on November 10, and beg that all who are interested in the future of professional photography will attend. The two photographic exhibitions will be open at that date. The time of meeting will be advertised. — I am, yours, *c., Thomas Fall. Jubj 19, 1893, 9, Baker-street, W. To the Editor. Sir, — " Pioneer's " reasoning in his latest effusion applies with as much force to the " mob " of amateurs who, according to him, are invading the profession. By the way, the Princess of Wales is a member of the " mob" of amateur photographers ; we will, therefore, use his own words to strengthen the said " mob's" position. Amateurs, " show to your fcUow-mcn that this great art science of photography, of which you are, or ought to be, so justly proud, and which you, as the ' amateur ' exponents of, have brought its varied works to such a high state of perfection," shall not be the sole monopoly of a limited number of professionals, but be free to all men, whether for in- struction, pleasure, or profit. As regards his other argument, that the retailing of intoxicating liquors is required to be done under Government licence, it is so appointed to prevent the injurious social results which would spring from its un- restricted sale, and there is not the remotest connexion between that and the art of photography. We will now further quote from his letter, using it as an amateur weapon ready forged to hand :— " Another point is almost entirely overlooked in connexion " with the proposed suppression of the amateur, " and that is, the vast army of persons who are employed, directly or indirectly, in the various manufac- tures and kindred trades " required to supply his wants, Ac "It behoves us to do all that lies in our power to protect this gigantic in- dustry, and not let its vitality be choked," as it certainly would be, if amateurs were wiped out with " a tax of ten or twelve guineas a year." I really did not intend to write again to you on this subject, as it looks like seeking notice for myself ; but really, as we are on the subject at all, it is as well, if possible, to discuss it thoroughly, and put an end, for a considerable time, to the chronic abuse which the poor amateur receives, and deserves to but a limited extent. The amateur is here, and he means to stay ; professionals must make the best of it, and adapt themselves to the changed conditions of their employment. If .\cts of Parliament were so potent as some think, no trade would suffer from depression, and we would only require a special Act of Parlia- ment for each trade to ensure all-round prosperity. I would recommend certain of your correspondents to study some elementary book on the laws of political economy ; also I would recommend to their attention that, if tliey want due respect to be given to them, they should show it to others, and not look down upon them as members of " a mob," or as a low class of society, for " 'I1ie rank is but the guinea's stamp. The man's the gow'd for a' that." — Buriu. —1 am, yonrs, 4c., Wm. Jas. Fabmsb. 68, Blackburn-street, London-road, Blackburn, July 7, I89S. 502 THE BRITISH JOURNAL OF PHOTOGRAPHY. [August 4, 1893 To the Editor. SiK,— In the previous paper under this heading great stress was laid on this fact, that the amateur problem is a very difficult one to deal with and not the slightest suggestion was intended to be conveyed against the class of amateurs as referred to by one of the correspondents of The Bkitish Jocrnal of Photography in the issue of the 23rd mst. It is possibly a moot point as to whether a man who makes scientific and experimental photography his hobby and delight is really an amateur at all True, he may only work for love and not money, but in any way he is not the man who injures the professional photographer, and it was clearly indicated that those who usurped the trade and the benefits apper- taining thereto must, for the relief of the professional photographer, be dealt with in some way so as to make the line of demarcation between the two stronger in the future than in the present. It the "miserable work" of some professionals referred to by " Amateur " is the cause of bad •trade, then he makes a strong argument for the utter eradication of such men by the examination test as advocated already in "Darkest Photo- graphy." If there are too many in the profession, and, as instanced by him, of there being tour establishments to a population of 1500 persons in one country town which he knew of, he makes a still further and atronger argument in support of the plan suggested above, and yet he winds up by saying that photography could sustain no greater blow to its •development and progress if " Pioneer's " wishes sliould be realised. The entire pith of the ideas suggested by " Pioneer" is to raise the profes- sional status and weed out the bad from the good, and the substance of ■" Another Pros.' " letter is strongly in support of the system advocated in " Darkest Photography," more especially in that portion that relates to the examination test. This was originally proposed in the scheme of " A National School of Photography," but when that was first mentioned it was considered too premature (then there was no vast army of amateurs). Now we are told that we are too late. Why? " It is never too late to mend," and, if the aid of the legislature has to be invoked for the benefit of the profession, it only shows to what an amount of importance modern photography has attained. Although we may invent as many new styles of portraits as we may choose, we can never expect any material or lasting benefit till such a time as the whole basiii of commercial and professional photography is reconstructed. There are no honours at present to be conferred on the professional photographer, however worthy he may be of them, as is the case in the sister arts of painting, sculpture, architecture, engineering, Ac. ; but, because they do not exist now, it is no valid reason why they should not be en evidence in the near future. With regard to amateurs being received into the ranks of professionalism, any one who follows photography as an additional Bonrce of bread-winning can scarcely be designated an amateur, and we only desire to place him on the same level as the professional, and we consider that he should be obliged to satisfy the proper authorities that be intends following it up as a business, and after he passes the test ■examination he can receive his licence or permit to carry on the business of a professional photographer. Amateurs will then remain within their own sphere, and not clash with the pro. while the latter is earning his means of subsistence, and what the amateurs may elect to do among themselves at their own Society's meetings no one wishes or desires to interfere with, we only want them not to interfere with us. Should, as previously mentioned, any amateur desire to enter the ranks of profes- sionalism, no more obstacles would be placed in his way than any one •else's, and therefore they cannot possibly sustain tlie slightest injury, should the scheme be carried out in its entirety as suggested in "Darkest Photography." — I am yours, &c., Pioneee. To the Editor. Sir,— Mr. A. Levy, of Paris, I notice has contributed a letter on the good old amateur question to the last number of The British Jocrnal OF Photography. In it he says (speaking of the amateur), " Why, with their knowledge and (superior to all) ingenuity, can they not make up anything portable to change their plates in, lic. ?" I should not like to accuse this gentleman of ignorance, but I should certainly say that at the time he wrote it he must jiuve been labouring under a condition of tem- porary absent-mindedness, or he would most certainly have known what ' most beginners know, viz., that there are at the present moment plenty of portable changing bags on the maiket, most of them the inventions of amateurs. So much for the first paragraph of his letter. The next paragraph I havenodoulit lie con-iJers unanswerable, and he is perfectly correct. Vituperation, however fals>; .and acrid, is never worth any one's while to answer, and the chief aigament(?), namely, that in former years amateurs used to use tripnds for instantaneous work, and now do not, and hence they are unworthy of all con«ideration, is altogether puerile. There is a certain amount of reason in the next paragraph about amateurs paying for the use of dark rooms (by the way, I have never used one yet that I not been charged for), hut even here our friend makes another great mistake. He siys that he (the amateur) " will find it as natural to pay for it as he does when he uses a wash room, or asks the advice of a doctor or lawyer." Perhaps it is natural in America to pay the above- mentioned people (and I conclude from his letter that your correspondent is an American), but in England things are different. In England a doctor, even if he has saved your life, is never considered to have an ab- solute right to any fee, certainly not as much as the grocer, or baker, or chimneysweep. The last paragraph of this effusion does not, as far as I can see, concern the amateur question at all. — I am, yours, *c., London, July 25, 1893. " " " KOREKT J. HiLLIEE. To the Editor. Sir, — I take it that none of my fellow-workers have any desire to say a word against the painstaking man who carefully works out methods, pro- cesses, etc., and freely gives the renults of his labours to al! and sundry who care to avail themselves of them. Tnis man is only too pleased and gratified to find that his endeavours have prov d successful, and looks for im further reward than that his process should prove cf s-ervice and of prHCtical value. The " Amateur Photographer," as »<■ know him, is noi related in any degree to this gentleman, wliom we are glad to meet, and tind many of his ideas happily corresponding with our own, and from whom we can generally learn something of great value relating to our own every-day work, and in clearing away many difhculties we have had no opportunity to ferret out for ourselves. His ideas are always put before us concisely and clearly, and we easily learn what be means. He is in no wise pedantic, and, as we might fay, is "clear, plucky, and ciisp, or free from fog," &c. We can get along well enough with him, and are happy in his company. But it is when the very d himself, armed with some slides and negatives, comes into your place, and you have to brace on your armour and in every way stand on the defensive, that your gorge rises, and you feel like murder in its most " lingering and boiling oil" form. He is& nuissnce, and our experience prompts us to inform him that we cannot undertake the work he proposes we shall do on his own terms, Ac. This probably loses us the custom of some of his friends, but that we must try to con- veniently foiget. I must say this amateur sails under false colours, and actually does injure my business in issuing photographs at a low rate, which he can easily do when he has an income derived from his legitimate business. Did your correspondent, " F. E. C. S.," take into account the value of the " employer's " services in producing those fifteen hundred negatives — say, three months' proportion of a salary of one or two thousand a year ? The professional employed seems to have been a very unbusinesslike person. " Audacious Operator " comes nearer the source of our trouble when he touches on the idiotic policy of men supplying free sittings, and throwing their work about as though no value whatever should or could possibly be attached to it. As he says, this underselling is killing the trade, and compelling men to combine a more lucrative business with their own, which really is one that should be considered as respectable as the profes^ons of medicine, law, &c., instead of which our " social status " ranks somewhere with the local billposter and chimneysweep. Not that their occupations are unworthy ones ; honest labour is no degradation. It was only last week one of our boatmen, earning about 18s. a week, said, commenting on our work, " Ah, well, there's some funny trades, but anything does for an honest living ! " Who is to blame for this condition of things but ourselves ? Why should the average photographer be so abjectly servile that he shall admit his work is unworthy the praise he knows it should attain ? Why is he in such a hurry to advertise " One splendid cabinet and three cartes for one shilling ?" At this rate he must "use up " 2000 sitters before he turns over 100/. This at, say, ten sitters a day (which he won't get), and counting Sundays in, would take him 200 days, during which time his rent, wages, &c., would be considerably in excess of his takings. Of course I know he looks for re-orders, but they won't amount to more than ten per cent, on the gross takings, and it doesn't pay, but merely keeps a certain class of sitters out of another man's hands who could get orders amounting to, say, from probably five to twenty shillings from each sitter. "Silex" says that, because materials are cheaper (he refers to pyro dry plates, Ac), we should drop our prices. How many negatives could we, in those days to which he refers, produce from our Winchester of collodion, our pound of silver, or our glass ? And, even with cheapened dry plates, how large do the amounts of our invoices seem for what goes so short a way ? 'The amateur cannot be credited with the lower prices "Silex" mentions; it is merely caused by the law of demand and supply, and where an amateur may use a dozen plates a professional may use hundreds. Nor do I think " L. C.'s " proposal that we shall adopt, say, the carbon, or any other process, will help us ; the amateur would as easily have his prints made by one process as another; he need not print them himself. The carbon is certainly a beautiful and permanent method of printing, but it is not at all difficult to work, and even here the tissue can be pro- cured sensitised ready for printing. Our only chance seems to be to form a union, or association, which shall insist on no photographer working below a certain rate, and I am sure the man getting three shillings for his cartes would only be too pleased to be compelled to receive six shillings for the same, for in every way would he be benefited ; not only would he be better able to pay Vogust 4, 1803] THE BRITISH JOURNAL OF PilOTOORAPHY. 60.'{ his exppnaes (for he would lose no" CTiBtom where prices were raised all ronnd). but he would soon be able to buy better acces- sories, backgrounds, Ac, and have better skilled assiatance. The union should be able to grant licenoes, and determine the ratio ot prices in each town, and this each photographer would be com- pelled to abide by, and it would also license all assistants who could pass a certain standard in technical and practkul proficiency. It is re- markable what a number of untrained young fellows are now in the profession, many even unequal to the task of varnishing a negative ; slovenly and dirty in their manipulations generally ; and what you, sir, about the time "Silex" writes of, used to call " sloppy photographers." In those days youths were trained to be scrupulously clean in many ways— plate-cleaning, collodionising, sensitising, Ac. Of this the modern assistant knows nothing, and seems to believe cleanliness unnecessary. The National Cyclists' Union has served a very useful purpose for cyclists, and why should not the National Photographers' Union serve the same for photographers? In the case of the Cyclists' Union, the licensing scheme was by many considered impracticable ; but, against endless troubles, they have done fairly well, and, to a certain extent, their scheme has done the service expected of it. The method of working, of course, is another story. The auctioneer keeps his business fairly to himself with his licence, and I think we might manage to do likewise. — I am, yours, Ac, Another Professional. To the Editor. Sir,— Recently a great deal has been said and written as to whether the amateur does, or does not, injure the professional photographer in his business. Most men are amateurs hanging on to the tail of some profession, which profession they usurp, either in its lower or middle ranks, ac- cording to their ability and the light of principle in which they regard what they do. It is a well-wom saying that " a man who knows nothing is sure to tell it the first chance he gets." The more ignorant they are, the more vain. They »i«.»( have an audience to show all their friends how wonder- fully clever they are. Amateur photographers will take you under any conditions, passable or impassable ; only, for goodness sake, let them take you. Their portrait work is mostly of a vile character ; but theur friends will tell you, " So and-So takes them beautiful." Whether the pictures are so or not, the price is " beautiful," being, in most cases, exactly nothing. Some would object to our claim to being injured in such cases, because we ought to produce better pictures than the amateur, and there can be no question that we do take better pictures ; but we cannot compete with the price, and when a thing costs nothing— well, people don't look a gift-horse in the mouth. Nowadays there is scarcely an institution but has its amateur photo- grapher, who does whatphotogiaphic work he is suffered to do for nothing, or for the good of the cause, he will tell you. Amateurs are a pestilence upon every profession. The amateur musician will play your organ for nothing, when some poor professional is down at heels and threadbai-e for lack of the salary that ought to be paid. He will assure you he does the work for the good of the Church, but that is not true; the fact is, Mr. Editor, he likes to have his sickening vanity tickled. The singer is the same, if not worse. He will scream at you till he nearly drives you mad, if you will only pretend to listen ; and you must use all your tact, and sometimes rude- ness, to induce him to stop. All these people only want an audience, and they will perform. They will assure you that they do no harm to the profession, and they do not —to those who are at the "top of the tree "—but they are depriving the more obscure of theii- livelihood, when time and money have been expended on acquiring the means thereof. — I am, yours, itc. JoHS Eayjie. To the Editor. Sir, — Having read with considerable interest the various letters which have been published in your columns relating to the depression in the photographic profession, perhaps I may be allowed to make one or two remarks. Some ot your correspondents have not learned tD differentiate between photography as a science and photographic work practised for business purposes. Hence, when replying to the remark often heard that amateurs have done professionals harm, they sagely remiirk that all or nearly all the improvements and inventions in connexion with photo- graphy are the result of the labours of amateurs ; and Mr. Stillman even goes so far as to ask, speaking of the professionals, " Did one of them discover photography ? " Now, I do not think the average intelligent pro- fessional photographer who knows anything of photographic history will for one moment refuse to give the amateur his due in this respect. The fact is, and always has been, the professional has to make his living out of the thing, and has not time for the elaborate experiments to which the moneyed amateur devotes his attention. We are most of us glad to use what our scientific investigators give us, and our practice and experience •soon enable us to use it successfully. AH thanks, then, to the genuine amateur photogiapher (not the dilettante), who does his work con amore, and gives to the world me result of his labours. Bat the qnestion m originally started is, Hm tbe amateur craze, faaa the vast army of amateur photographers injured the bimineif of photo- graphy? Is the present depression attributable to tbe amateur'/ To these questions it is impossible to give a definite answer. Undoubtedly the work of the amateur in many cases supplants that of the professional, not necessarily because it is better, though it sometimes may be, bat because it is good enough ; because, too frequently, the public taste is so bad that a mediocre result for nothing or for cost of materials is pre- ferred to a good photograph at a good price. Ho lar, then, harm has been done, but to what extent? The damage tbe professional has re- ceived in this way is a mere bagatelle to tbe harm he has done himself and his brothers. The self-inflicted wounds have been ofttimes enume- rated — price-cutting, indiscriminate gratuitous sittings, turning out of inferior and fugitive work, and lack of enterprise. It was natural that prices should rule somewhat lower as materials and labour became cheaper, but, for some of the starvation prices now asked, photograpben have only to thank their own cut-throat policy. No, we may blame the amateur, or the public taste, or anything else we like; but, as Casca says in Shakespeare's Julius Cwsar, " It is not in our stars but in ourselves That we are underlings. " But this is no consolation to the "poor professional." It does a starving man little good to preach him a sermon on his past follies. We want to alter the present state of affairs as speedily as may be. The letter of "L. C." in your last week's issue appears to me a» practical and to the point as anything I have seen. One of his remarks I take the liberty of quoting, " When your house is on fire do not begin to abuse the man over the way because his building interferes with your ancient lights. On the contrary, take off your coat and look around for a bucket." This is the principle which, acted upon, will lift professional photography out of the mire. Taxation won't do it, boycotting the amateur won't do it, licensing the professional won't do it. Those of ns whose hearts are in our work must strive to obtain better technical and artistic results (and, in spite of Mr. Guardia's sneer, many portraits pro- fessionally produced now are works of art, although not of tbe hand camera), we must show more business ability, energy, and enterprise, we must be willing to sacrifice a little for the present in order to educate the public taste so that they may appreciate a higher quality of work and buy it ; and we must remember that, as photography as a business has n'.t been depressed in one year or two, we can't raise it again in so short a time. — I am, yours, Arc, Charles Henry Hewitt. King's Lynn, July 22, 1893. To the Editor, Sir,— I have followed with interest the discussion now going on in your Journal, "Depression in Photography." Now, as an assistant wLo has had fourteen years' experience, I think there is another matter of more vital importance to the profession — that is, how to find a good assistant and how to find a good master. In applying for a situation, I always find the place is described as first class or the best in the town, and the situation will be permanent. Speaking from my own experience and that of other assistants I have met, in very few cases has that description been justified. To a man who has been educated in a good house it is, to say the least, just a little depressing to find the best house in the town to be a wooden shanty studio 18 ft. by 12 ft. Now, how are we to know what class of place we are going to ? On the other hand, a photographer requires an- assistant. He gets lots of applications ; three parts are well recom- mended, and send good references from the best in the town. But how is the master to be better informed than the poor assistant ? Generally the man with the most cheek gets the place, and I think I am safe in saying they are the most ignorant, will go for a moderate salary, and perhaps have only a couple of years' experience, yet they are able to keep a good man out until he is starving and has to take any poor place he can get. I think this is demoralising, conducive to bad work, changing of hands, and low salaries. Could we not have a stiff examination that would clear the market ot duffers ? Let it be like doctors, lawyers, and masters ot vessels, liable to have their diploma or certificate taken away ; then there would be none but good assistants, and, as a consequence, good photographers. Hoping that some abler pen will take the matter up, — I am, yours, Ac, July 2, 1893. Assistant. [Correspondence on this subject must now close. — Ed.] Swljanse Column. \* Ifo charge is made Jar inserting Exchanges of Apparatus in this column ; but none mil be inserted unless the article wanted is definitely stated. Those who specify their requirements as "ani/thing useful" will therefore understand the reason of their non-appearance. The full nam^ of the advertiser must in all cases be given for publication, otherwise the Exchanges will not be inserted, Will esckangre Dallmeyer 2c lens (cast W. \5».) tot good hand camera.— Addrws, Dbukt Stows, Bedford. 504 THE BRITISH JOURNAL OF PHOTOGRAPH 1'. [August 4, 1893. TVUl exchang^e Merveilleus half-plate set for hand camera, magic lantern, or quarter plate rectilinear lens.— Address, G. Mooee, Bnckfastleigh. Will ezchacffe ratchet safety bicycle, ball bearings all over, for good hand camera (quarter-plate or 5x4).— Address, G. M. Miller, IS, Cambridge-terrace, Belgravia, London. Harrison's head rest, Knox burnisher, ten-inch bar, brass plate lettered " Photo- graphic studio," in exchange for hand camera.— Address, S. E. Daties, Broughty Ferry, >'.B. Wanted, good lens for hand camera ; will exchange Dallmeyer's whole-plate tele- scope, new meter, only used a few times, cost 30s.— Address, J. Allkx, 2, Pyrmout, Barber-road, Sheffield. I will give in exchange a Mawson's cabinet lens, in good condition (but no cap), for a camera and set of Gem fcnses in good condition.— Address, J. Barber, 6i, High- street, Loftus, R.S.O. Will exchange 5x4 camera, with carrier for carte-de-visit portrait lens and rapid rectilinear to fit same, for 10x8 or 12x10 camera; difference in cash. —Address, Kd. Aetis, 40, Wesley-avenne, Mutley, Plymouth. Wanted, 5x4 rapid rectilinear iris diaphragms, in good condition, in exchange for silver Geneva watch, in good condition and working order; approval.- Address, J. K. Smith, Little London, Rawdou, near Leeds, Yorkshire. Will exchange Knight's Pictorial Gallery of Arts, in two splendid voltimes, 4000 wood- cuts and steel engravings, in first-class condition, for half-plate camera, without lens or tripod.— Address, C. Tatloe, 15, Bradford- road, Batley, Yorkshire. Will exchange new strong oak 12x10 printing frame, Fallowfield's make, for two strong oak whole-plate printing frames, or one whole-plate and one half-plate. Will pay difference. — Address, G. F. Jessett, 7, Batoum -gardens. West Kensing- ton, W. :Splendid portrait lens, takine up 15x12. Also folding tricycle by Singer &; Co., electroplated throughout. Wanted, modern portable outdoor outfit, for groups 12x10 or 15x12; also whole-plate studio universal camera, and 3c lens.- Address, XoNSDALE & Co., 46, Stroud Grefln-road, London, N. ainstDcrsf to Corresponticnta. *,* All matters intended for the text portion of this Jouenal, including queries and Exchanges, must be addressed to " Thk Editor, Thk British JouRyAL OF Photography," 2, York-street, Covent Garden, London. In- attention to this ensures delay. ■*»• Correspondents are informed that we cannot undertake to answer com- munications through the post. *»* Communications relating to Advertisements and general business affairs should be addressed to Messrs. Henry Grkknwood & Co., 2 York-street, Covent Garden, London. "*,* It would be convenient if friends desiring advice respecting apparatus, faihires in practice, or other information, would call at tlie Editorial Office either on Wednesdays from i to 6, or Thursdays from 9 to 12 noon, when som£ one of the Editorial staff will be present. Photographs Registered :— William Bond, Norwich.— P;io(ojra])h 0/ Ji'oi-u.-ich /rom tht JforfK. Jolin Arthur Draycott, Birmingham.— Sii Pliotoqrajihs of Kr. M. P. ManAeld. Kate Alice King, Notting Hill, Vf.— Three Photographs of the Rev. Arthur Tf' iiliom- son. D.D. Blackburn-.— Would "E25" please send our publishers Ms name and address. M. C. K. — The print seems to be over-printed and over-toned, and also appears to have been exposed too much to light during the toning. William Berry asks: "Do you consider the worlc done by the electric retouching pencil superior to the ordinary retouching pencil ?" — No. Wasp. — As the coloured supplements to the Graphic and similar periodicals are constantly framed and sold by picture-frame makers, we take it that you can do the same without " becoming liable to prosecution." •C. TiLY. — 1. Dr. Miethe's address is Potsdam. 2. We cannot say whether his teleo-objective is patented in tlie United States, but believe it is. 3. See the Journals from October 30 to December 4, 1891, inclusive. R. Churchwell. —The action is not due to the tissue acquiring insolubility. That idea was fully discussed twenty or more years ago. If you make the experiments you propose, you will be satisfied on the other points. Arthur Clayton.— The copyright is vested in the author of the work— that is, the one who takes the picture. The other question rests upon the terms arranged and the conditions under which the picture was taken. ALE.^CANDER Maointyre.— When prints have been weS toned with gold, we have known ink stains quite removed by treating tftem with hydrochloric acid. It will be advisable to try it at iirst on a print that is of no value. Rubens.— If the picture is copyright in Germany, there is little doubt, under the International Copyright Act, that it is also copyright here, as that law confers equal copyright in all nations within the Union, and Germany is. S. Bellow. — The formula is impracticable. Twenty grains of gallic acid are not soluble in an ounce of cold water. Its solubility can be increased very materially by the addition of glycerine or of alcohol. Neither of these additions would be harmful. P. Daley. — A good article may be relied upon from any of the houses mentioned. S. .1. (Berks). — The chalky appearance of the lights and the blackness of the shadows in the photograph of the interior of the building, are due to very inuch under-exposure. In the next attempt, if another is made, give five or six times as long, actinometer readings notwithstanding. A._ B. Z. (Bristol). — Any elementary work on photography would supply the information. A formula is given on page 792 of the Almanac. The bath must be tested from time to time with the argentometer, and its original strength made up either with crystals of nitrate of silver or a stronger solution. Buckinghamshire. — If you wish to become, as you appear to do, a pot hiinter, and acquire a lot of medals, make it a point to show at all the minor exhibitions, such as little local societies that admit outsiders. By following this course, if you send good work, you will soon acquire plenty of medals. R. A. C. — It is doubtful if you can legally demand, as a right, though a rate- payer, to enter the church at any time to photograph the interior. How- ever, a polite request to the clergj-nian will, no doulit, secure the necessary permission, and tliis will, we imagine, prove more agreeable to all parties than asserting rights, real or imaginary,. Aug. Whkeler.— There is little doubt, as you have told your friend, that the spots are due to minute blisters caused by the hot climate. We should recommend alum before fixing, w-itb a pretty thorough washing between the operations. Slower plates would certainly be better for your friend for general work during the hottest weather. Mr. W. C. Hemmons asks : " Will you inform me, for the purposes of our proposed exhibition, where I can obtain the addresses of the chief English and foreign papers and magazines relating to photography, and the cost of such a hand-book, if there be one .' " — We believe that such a list is published at the cost of a few pence. B. R. A. — Tlie only way by which the spots or markings can be removed from the negatives is by carefully scraping them out with a penknife. If you are not pu fait with that kind of work, the negatives should be phaced in the hands of a skilful retoucher. The emulsion with which the plates were coated seems to have been defective, and the fault is not due to the operator. The sample negative sent has been destroyed as requested. Corrector. — .Although we have' had but little experience with the corrector mentioned, it will certainly be quite possible to use it in conjunction with a focal plane shutter. The nearer it is to the plate the better it ought to work, but this will depend upon tlie curvature of the concave surface and the thickness of the glass. We know of no one who makes such correctors, but we have no doubt that any lens-grinder would undertake the work. T. Bradley. — There are several causes that will account for the ink adhering all over the paper, and refusing to leave the parts protected from liglit in photo-lithograjihic transfers. A very prolific cause lies in the bichromated gelatine becoming partially or wholly insoluble, or non-,absorptive of water. This may be due to its being kept too long, or from it having been exposed to the light, &c. Another very common cause is the unsuitability of the negative — the dark parts not dense enough, and the lines not transparent. There are other causes, but these are the more general ones with novices. J. C. T. complains that all the formula; published for photographic transfer inks seem complicated and troublesome to work, and asks if we can suggest something simpler and more suitable for a beginner. We can, and that is to purchase the ink ready-made from any of the dealers. The beginner can thus ensure having an article suitable for the purpose, and that is more than can be relied upon with a novice's first few attempts at ink making. All who have had any experience in transfer-ink making know quite well that it is not only a troublesome but a very unpleasant operation without special appliances. D. Davey writes : " Wishing to produce some prints on a very rough drawing — or rather tinted crayon — paper of a warm grey tone, I sensitised some, accord ing to several formuhs, and it was a failure in every case. As soon as the paper was dry the original colour was quite changed, and it had become a yellowish brown with innumerable dark brown and nearly black spots. As different formula; were tried, and all with nearly the same result, I conclude the paper is at fault. As the tint and surface is exactly what I want, is there anything 1 can treat the paper with to purify it '! " — We fear not. Paper of this kind is made specially for artists use without regard for any other. However, these papers vary considerably in theircomposition, according to dif- ferent makers, therefore it is quite possible that a different make will answer the purpose better. If it is possible to obtain the same tint of foreign make, we snould recommend a trial of that. OOKTENTS. Paoi the function of si'lphite of soda in development 189 depression IX PHOTOGRAPHY 480 THE INFLUENCE OF DEVELOPMENT ON GRADATION. By H. J. CHANNOX JIH AMERICAN NOTES AND NEWS 193 PHOTOGRAPHIC METASTASIS. By HUGH BREBNER *M ON THINGS IN GENERAL. By FREE LANCE 485 DODGES. By C. O. GREGORY 490 PlOB SEASON.IBLE NOVELTIES 407 OUR EDITOBUi TABLE 497 NEWS .\ND NOTES 4»7 RECENT PATENTS 4» MEETINGS OF SOCIETIES -.... 496 FORTHCOMING EXHIBITIONS 6» CORRESPONDENCE !^ EXCHANGE OOIUMN 603 ANSWERS 10 C0BRESF0NDENI8 THE BRITISH JOURNAL OF PHOTOGRAPHY. No. 1736. Vol. XL.— AUGUST 11, 1893. HALATION, AND METHODS OF PREVENTING IT. A LETTER which we have received from Mr. C. E. Pettit, and •which will be found on another page, reminds us of the fact that of late considerable attention has been bestowed upon the subject of the preparation of plates which shall give freedom from halation. Very soon after Mr. G. Marlow had directed the notice of the public to the nature of halation — now over thirty years ago — Major Russell tried numerous experiments with a view to ■cure the evil, and wrote much concerning it His first sugges- tion was to employ orange-coloured glass as the support of ■the sensitive film. After being developed and fixed, the negative pellicle had then to be stripped from ofif the glass in ■order to its being printed from. This was found to prove an effectual remedy ; but the trouble and risk of removing the film was recognised, and he overcame this by giving to the plate, of ordinary glass, a coating of non-actinic colour ; and this, when dried, was found to answer the intended purpose quite well. This was for dry plates; but, when the wet-collodion process was employed, the same end was attained by pressing a sheet of wet red blotting-paper on the back of the plate. Things remained in this condition for many years (as they do with the majority of workers up to the present time), when a remedy was proposed by Mr. Carey Lea, and others, in the imparting of a yellow stain to the emulsion by which the plate was coated, a stain which should be capable of being removed in course of the subsequent treatment to which the plate had to be subjected. This stain, in the form of an inert substance, was afterwards discontinued on accoimt of the allegation that it impaired the sensitiveness of the bromised film, and both Carey Lea and Col. Stuart AVortley subsequently gave pre- ference to the iodide which, while believed to be not quite inert when used along with bromide, undoubtedly diminished halation by imparting greater density to the film. Before proceeding further, we pause for a moment to describe, for the benefit of our younger readers, a method by which they •can see for themselves the precise effect produced by placing blotting-paper in optical contact with the back of the plate. Hold an ordinary clean plate of glass obliquely so as to reflect the image of a gas flame from its surface. Examine this atten- tively, and it will be found that, between the eye and the primarily reflected flame, there are several others, each fainter in succession. If a sheet of the red blotting-paper is pressed against the back of the plate, no alteration whatever in the number of reflected images is produced ;] but apply a wet sponge to the paper while still in position, so as to wet it thoroughly, and thus establish optical contact between it and the glass, and instantly all these minor reflected images dis- appear as if by magic, the primary image alone now being visible. This demonstrates in a very simple and efifective manner the advantage of backing the plate as a means of preventing halation. This same kind of reflection occurs when the plate is coated with a sensitive film, and it is the stronger in proportion to the translucence or thinness of the coating. If the plate be very thickly coated with any light-absorbing medium, then will there be no halation of the nature now being described. The experiments described should be made at night. The imparting of opacity to the film whilst at the same time securing maximum sensitiveness was suggested by us seventeen years ago, the meaus being double films. Writing on the subject two years later (in 1878), a contributor to our pages, Dr. Nicol, suggested a strongly coloured substratum, which, interposed between the glass and the sensitive coating, should act as an anti-halative until the exposure had been made, when, by a subsequent operation, the colour should be discharged. Curcumine, the colouring matter of turmeric, was believed by him to be the best, or amongst the best, sub- stances to employ. Writing concerning this at the time, wo t spoke of its superiority to methods of staining the sensitive emulsion then known, but which, for reasons given, had re- ceived no great amount of recognition. But, whereas Dr. Nicol had spoken of albumen then employed as the popular substratum, we suggested gelatine as a more suitable one, seeing it would so readily part with the colouring matter when its function had been completed. Just subsequent to this, the Rev. H. J. Palmer wrote to us saying that, at the last meeting of the Liverpool Amateur Photographic Association, he h;wl stated that the freedom from halation which he had experienced had been proved to be due to the shghtly yellowish tinge of the glass plates on which he had spread his emulsion. He says he coated his plates with gelatine emulsions of two kinds, viz., one which gave a very slow but dense film, and one made from Keunett's pellicle, which was moderately rapid. He exposed to the inside and east window of a church under conditions of light and atmo- sphere which are invariably provocative of blurring in its worst form. The sun was shining brightly, but the wind was in the east and the air filled with haze. In every case the test proved entirely satisfactory. coo THE BRITISH JOURNAL OF rHOTOGBAPHY. [August 11, 1893 From the few notes here given, Mr. Pettitt will find that he may experience difficulty in maintaining his patent, excellent although the thing is in itself. We have of late received much correspondence relative to the subject generally, and trust that even such a brief reca])itnl>ition as we have given may tend to throw some light upon it. Those who wish to inquire more thoroughly into the matter should read the writings relating thereto of the late H. B. Berkeley and others. FIXING AND WASHINCi SILVER PRINTS: MESSUS. GRUNDY AND HADDON'S EXPERIMENTS. Tjie paper On the Amounts of Silvfr and Hypo Ufl in Alhumen- ued Paper at Different HUiges of Washing, read by Messrs. F. B. Grundy and A. Haddon before the London and Pro- vincial Photographic Association on Thursday week, and which will be found in another i)art of tlie tloLRXAi., is a valuable contribution to our knowledge of a subject which, notwith- standing its extreme importance, has never yet been fully investigated, and consequently not understood. The paper, brief as it is, concentrates within its small space the essence of a series of laborious experiments to determine the influence and .action of the fixing and washing solutions upon alburaeno- chlo o-nitrate of silver, and although undoubtedly of great inte.-est to the chemist and the investigator, will, we do not hesitate to say, have more value for the practical photographer than any pajjer read before any society in recent times. We endorse the commendatory remarks made in the course of the exceedingly interesting discussion which followed it, and trust that it will stimulate other investigators to take up the study of many vexed or doubtful points met with in practical phonography, and strip them of their obscurity. Messrs. Grundy and Haddon's objects in carrying out their researches were, to quote their own words, " to determine the time the print should be washed," and to " endeavour to deter- mine the cause of the fading of the finished print." The results of their experiments — the methods and accurate applica- tions of which it would be difficult to take exception to — un- doubtedly indicate that they have not been unsuccessful in those objects. Summarising the conclusions arrived at, and taking the experimental data as typical of what actually occurs in the fixation and washing of silver prints, it appears that the fixing bath leaves behind a residuum of silver and sulphur compounds, which, although presumably soluble in water, are irremovable by washing within the limits of from five minutes to nineteen hours. This, according to general photographic practice, we may accept as marking the minimum and extreme periods of wash- ing adopted. While there is, of course, nothing new in this, it is possibly the first time that the power of the fixing bath on the sulphur and silver salts left in a " fixed " print have been accurately gauged. ' '" • ' The principal outcome of these experiments, from the point of view of every-day practice, however, lies in the fact of the ivscertained limitatietter printing yiei/atite,''Kha developed. Printing an under- xposed negative under white paper seemed to have quite as good an iTect, and, as /^ropec exposures were always aimed at, the advantage of >xtra light was not very palpable, anyway, whatever the reason the jirocess was dropped. Supplementary lighting seems to have another effect, which does not show itiwlf by the production of more detail, but density instead. A very small modicum of diffused light, such as is reflected from the t:side of a camera that bas become somewhat shiny from use, or from the lens mount, seems not to t'oar the plate, but to give rather ah increase of density to the negative. The line between fog and density is rather diflicult to draw ; so many conditions may interfere, espe- i i;iliy length of exposure, it would be interesting to know for certain low raucli light can be u.sed with advantage. Of course, with wet 1 ollodion the mere matter of density was not thought of, as most negatives underwent redevelopment either by adding silver solution to the first lot of developer, or by ))yro and silver solution after the development proper had taken place. Sufficient density with the first application of the developer was scarcely e.xpcted : so, under these circumstances, if extreme density wat conferred by supplementary lighting, it was neglected. Now we work under different conditions, and it might be worth while to go over the process again. I would suggest to any one owning a stereoscopic camera that a little light colour inside the camera or lens mount, for one half the slide, would show if any advantage is to l)e expected in the matter of density by the supple- mentary light thus introduced. It stands to reason that, with our rapid pktes, it must be very little, or it will result in fog instead of density. Anyway, I suggest the idea of trying it to those who have more time and opportunity than I have myself. Edw.\rd Dunmork. ON THE CONSTRUCTION 0¥ INTERCHANGEABLE LENS SCREW FITTINGS, [Photograpliio Society of Great Britain.] Thebk is being established among you a system of standard inter- changeable fittings for the attachment of lenses to cameras ; a system which will presently enable you not merel3' to covet your neighbour's lens and to screw it without difficulty in your own camera, but will entirely simplify the attachment of your own lenses, so that you may have on each camera one flange to suit the largest lens you use, and every other instrument will either fit this flange direct or be carried in it by a standard adapter. Moreover, the lens will not, as of old, screw and arrive home with utter disregard to your wishes. One will not have its diaphragm index set up where you need a mirror to read it, nor another down where you cannot see it, and all where you have to hunt for them. They will arrive home in one place which may be of your own choosing. And, in attaching a lens to its flange, you will not have to seek, in patience or in despair, the suggestion of a tendency toward engage- ment of the screws. You will place them with their zero marks together, knowing that they will immediately engage on being turned, and that you cannot cross the threads. You will know that exactly three turns complete the engagement, and in removing the lens your mental anguish will be neither protracted nor acute, for you will know precisely when to expect the instrument to fall upon the floor. The old want of system and uniformity in these things is being gradually dispelled, and one by one lens-niiikers are realising the im- portance of adopting the Society's Standards for the benefit of their customers. Such a change, involving so many personal interests, cannot be suddenly accomplished everywhere ; but, to those who view the great inconvemeiices which will lie removed by the general adoption of the one standard, there is no doubt that in the course of time, and with constantly accelerating speed, this change will be accompUshed. I speak to-night on the technical side of the subject, of methods of making and measuring such screws as are applied to photographic lenses for this purpirse. and in bringing tlii.', part of the subject before the I'liotograpbic Society, 1 venture to think it may prove interest- ing even to those who are not mechanics. Besides its intrinsic interest. however, the subject is of considerable practical importance to photo- graphers at the present time, because, while tliey are asking and will continue to ask, for standard interchangeable screws, it is a fact, which I have no hesitation in stating, that the methods of screw-making generally employed by opticians are quite inadequate to secnre that degree of accuracy on which true interchangeability depends. Before photographers can attain the full advantages of i^tanuards for their lens screws, the mechanical practice of opticians must rise to a much higher level of culture than it has reached at present, Jlv work in connexion with the Opticians' Conference appointed by the Convention Committee, and as a member of the recent Standard's Committee of thi.s Society, has enabled me to judge of thi! regard which opticians generally pay to the technical work of "screw-making, and I see there has existed among us in the past a certain disregard, sometimes even bordering on contempt, for over-much mechanical accuracy. It is quite natural that the optician, whose .study and .skill are de- voted principally toward de.signing and fashioning beautiful glas.s work, should regard too slightinsrly the constructiveVork and the skill of the mechanic, the worker in metals, and in the pa.st the need of critical accuracy in screw making ha* not been widely felt as soon it will be, for the need has arisen with the present cry for interchange- ability : and, if we are to secure for photographers and for photography the great advantages for which that cry Ls raised, our neglect of accuracy must be banished and scrupulous care must take its place. AVe must all learn the use of true standards of length, and of fine measuring appliances, so that the work of the optician may be supple- mented by the work of the skilled mechanic, I am a young man, and I want to see these standard fittings every- where adopted and properly made before I am old. For several years in the course of my work 1 have been deeply interested in improving methods of making and measuring such screws as we contemplate, and I have resolved to publish some of the results of my own work, in order, if possible, to make the way easier for others. Intebchangbability. There is an important difference which I ask you to observe between such interchangeability as we need with photographic lenses and such as is commonly secured among bolts and nuts and among gas fittings ; it is this, that bolts, and nuts, and gas fittinss may be forced together with wrenches and tongs, while our lenses must never be subjected to such treatment, they must go together freely and without strain ; and we may conveniently distinguish this by calling it a condition of free interchangeability. Now, I should like you to realise what this condition means and involves. Let us suppose that we have fifty lenses, each with a stan- dard two-inch male or external screw, and fifty flanges with corre- sponding two-inch female screws. These are freely interchangeable, when any lens will screw into any flange without difficulty. There will be 2500 distinct combinations formed in trying all these screws together. Now, if one of the male screws be large, even to the small extent of only one-thousandth of an inch on its diameter, this will effectually prevent its entering every one of the fifty flanges which are of normal size. It is thus evident that every male screw must be at least as small as the normal or standard screw. In the same way it may be shown that every female screw must be at least as large as the normal. These are the conditions of free interchangeability amouir screws, and I ask you to note them carefully. The small amount of one-thousandth of an inch is sufficient to prevent the screws going together at all. Errors much smaller than this are still sufficient to prevent free interchangeability ; and it is thus evident that extreme caie and accuracy should be observed in measuring such screws, and in making and measuring the gauges with which they are tested. Pai- ticularly is this evident when we remember that it is sought to make the lenses, not merely of one maker but of all makers, freely inter- changeable, and that the various makers cannot readily compare their work or their gauges, but must rely upon the accuracy of the standards of length with reference to which their took are constructed and periodically tested. Thk Mkasumng op Screws, A screw such as you see in the diagram (fig. 1) has three principal elements : — (j)) The pitch of a screw, which in general terms we speak of as coarse and tine, is the distance between two successive threads, or turns of the thread, measured in a direction parallel to the axis of the screw. At present we are not concerned with method.3 of measuring the pitch of a screw, (d) The nominal diameter of a screw is usually the measure of the full outer diameter of the male screw. Thus, the two-inch standard male screw measures two inches over all, and it is a simple 510 THE BRITISH JODRNAL OF PHOTOGRAPHY. [August 11, 1893 thing to measure this diameter accurately hy placing the screw between the plain measuring faces of a micrometer gauge or measuring machine. In order to fulfil our condition of free interchangeability, it is necessary not merely that this full outer diameter of a male screw be at least as small as the normal ; it is also necessary that upon the sloping sides of its threads and at their base or root, the screw should be everywhere sufBciently small. Equally important then with the full outer diameter in securing free interchangeability of screws is the thread form, which determines the size of the screw on the sloping fides and at the bottom or root of the threads. The form of thread is taken as its cross section in a plane containing the axis of the .screw. The diagram shows the form adopted in the Society's Standards, and which is known everywhere as the Whitworth thread. It is a form beautifully adapted to the purpose for which it is chosen. It is planned in this way (see fig. 1) : A base line is divided into sections, each of a length equal to the pitch of the desired screw. Upon these sections of the base line, isosceles triangles are formed by drawing lines inclined to each other at fifty-five degrees. A line parallel to the base line and touching the apices of the triangles will stand above the base line 96 of the screw pitch, and will include another series of triangles between the first and similar to them but inverted as at (A). By means of equal circular arcs, one-sixth of the height of every triangle is rounded off its apex, as at (B), leaving the form of thread as at (C). The depth of the Whitworth thread is -64 of its pitch. Suppose tliat we have a screw already made, and we wish to •^ f I Fig. 1. % measure its thread form. The full outer diameter of the screw is easily measured by placing it between the plain jaws of the measur- ing machine, as shown at A in fig. 2. This fiill diameter of the screw is represented by the height of the first thick black line to the right. Tlie depth of thread in any place may be measured by pro- viding the little test piece shown at D, and on a larger scale "below in the diagram. This little hardened steel bar of triangular section has its lower edge very slightly rounded, and its measurement, C, accurately determined. When placed along and between the threads v: i-_ Fig. 2. of a screw in the direction shown at D, it touches the screw only'at the root of the threads, and, by measuring the diameter of the screw, including the test-piece, in the manner shown by the figure, it is easy to determine the depth of thread ; for, if we subtract from the measurement so obtained the constant measure, C, of the test- piece, we get a result, indicated by the shorter thick black line, which is less than the full diameter of the screw by exactly the depth of the thread. With due care, and with simple appliances, these measurements may be made correctly within about one five-thou- sandth part of an inch, which is sufficiently accurate for practical purposes. The diameter of a screw, as measured on t^e sloping ades of its threads, may be determined by the aid of a simple application of trigonometry. One easy method, applicable under certain conditions when the angle of thread is known, is to use a small cylindrical gauge placed along and between the screw-threads, so that it bears only against the sides of the threads in the manner shown in fig. ;i. The question to be solved by using this little gauge is this — Are the threads of the screw, so to speak, too fat, as at F, or too thin as atT? You will see that, if the threads are fat, the little gauge will stand too high aboTe their tops. If the threads are thin, the little gauge will sink too low between them. It is a simple matter to dis- cover just where the gauge should stand in relation to the thread- tops, and it is simpler still, and just as useful, to find where it should stand in relation to the base or root of the threads. If the sloping sides of the threads had been continued downwards to form a thread not rounded at its root, but sharp, it would have been of the form shown in fig. 4 ; and, knowing both the diameter of our little cylindrical gauge and the angle between the sides of the threads, it needs only a simple application of trigonometry to decide where the gauge should stand in relation to the point P. We know, by the construction of the Whitworth thread, that an amount equal to 'It) of the screw pitch is rounded off the sharp angle to form the rounded Fig. 4. root of the thread. Knowing, then, how far the cylindrical gauge should stand above the point P, we can easily find how far it should stand above the base or root of the threads, and how far above their crests. For practical purposes, the necessary calculations may be made once for all, and I prefer to construct for each pitch of screw to be dealt with a small cylindrical gauge, of such diameter that it .shall stand, when in use, one or two-thousandths of an inch, or some such simple recorded distance above the crests of a perfect or normal thread. The radius of such a gauge for this purpose may be found by the formula : — 12-5d-p 3'16.56 ' where d is the depth of thread, and p the desired convenient pro- jection of gauge above the crests of the thread. The main features of this problem are shown in the diagram (fig. 4). If it be necessary to measure the angle between the sloping sides of a screw thread, it- may be done by using a second gauge, small enough to lie between the threads close down at their root.* W. Tatloh. * The use of trigonometry for this purpose is naturally not new. It is em- ployed in a very different way in the measurement of the Sellers form of thread by Messrs. Pratt & Whitney, of Hartford, Conn., in whose works I have had the pleasure of seeing it applied. The use of small cylindrical gauges such as I have described was first suggested to nie by Mr. Barber, the superintendent of Messrs. Whitworth & C'o.'s gauge department ; but, so far as I am aware, the application in the w,ay I have explained is novel. (To he continued.') August 11,1893] THE BRITISH JOURNAL OF PHOTOGRAPH Y. «11 DOUBLE TONES IN QELATINO-CIILOKIDE PAPERS. Onr of the mo't freq\ient imperfections which I meet in gelatino- chloridi' printing-out papers' is tliat tliero is a marked double tone. This defect is nioft apparent in the lialf-tones of the print, and especially noticeable at the edges of vignettes, and, in fact, in all portions of the picture where there is a transition in gradation from half-tone to a lighter tint. I frequently hear this defect attributed to the use of sulpbocyanide of ammonium as a toning adjunct,and I have myself found, at various times, that a sulpbocyanide toning bath would give it. As a matter of fact. I am inclined to believe that the use of sulpbocyanide does predispose to this defect, and mainly because it is infrequently used with a small enough proportion of the salt to the water, and with an insutticiency of chloride of gold to do the toning work with facility. This is a point which it ought hardly to be necessary to emphasise, as the makers of P.O.P. have frequently drawn attention to the necessity of not overdoing the quantity of sulpbocyanide per ounce of water. It need not be inferred from this that a sulpbocyanide bath, properly constituted, will not make good, even, and single-tuned prints in ptflatino-cbloride ; on the contrary. Nor, on the other band, are other toning baths free from the trouble. Generally speaking, it may be taken that a double tone in a printing-out paper indicates one of three things: — 1. Insufficient gold. !i. Too large a proportion of the tonincj adjunct. 3. The use of a partially exhausted batii. Turning attention for the moment to the first cause, it is tolerably certain that an emulsion paper requires more gold to tone a given number of square inches of surface than does ordinary albumenised paper. This, instead of being a weakness, may well be claimed a strong point for gelatino-chloride, for a strongly substituted gold image is likely to be more stable and permanent than a half-toned one. The question of the cost of production is hardly one which should enter into the question at all, although it is, cceferis paribus, a factor. A.S a basis for estimating, we may assume that, under the best con- ditions, a sheet of albumenised paper will require one grain of chloride of gold to tone it to a warm colour. I don't think we can e.^pect to tone a sheet of gelatino-chloride paper with less than three grains, but the extra cost spread over the prints is of no importance, compared with the advantages of the emulsion paper, such as the keeping qualities and evenness of coating. This latter is a point of great importance when we remember that every sheet of our old friend albumen bad a thick end, and a corresponding thin one, due to the draining of the salted albun-.en during the drying process. Not only must there be a sufficiency of gold, and not an excess of sulpbocyanide, but the solution must be sufficiently concentrated to change the colour of the prints in a reasonable time. A prolonged toning with gelatino-chloride papers generally means that double colours are obtained. I have recently seen some very quick toning baths worked with bicarbonate of soda, chloride of gold, and water only. The formula stands about — Chloride of gold 1 part. Bicarbonate of soda 20 parts. "Water 480 „ In such a bath the prints, previously well washed, tone in a phenomenally short time — under two minutes. But the tones thus obtained are, to my mind, not very attractive, ranging towards cold- ness and greyne.«s. There is also the added disadvantage that, with so rapid a change in colour, it is to a large extent impossible to secure other than one tone, viz., the limit to which the bath will go. Moreover, there is an inclination to over-tone, or to eat away the lines of demarcation between the lighter tones, or at the edges of vignettes. This trouble with the edges of vignettes and of the lighter tones is not by any means restricted to printing-out papers, in which it might be supposed to be caused by a possible mixture of sensitive ealts in the emulsion such, as, say, the chlorides and citrates. It might be plausibly argited that the discolouration of the finer edges is due to a slight separation or imperfect admixture of these salts, and not to the toning action at .all : in other words, that such an emulsion is but a mechanical mixture and not a chemical compound. It is quite pos- sible and even likely, that an irregularlv constructed emulsion would suffer from such a defect; but it must also be borne in mind that all photographic images first show signs of deterioration in this same part, viz., in the lines of demarcation between the finer tones. This is only another way of stating that chemical action commences in these portions of the picture, and the defect has probably come within the observation of many of my readers when reducin;? a negative with hypo and ferrideyanide of potassium. The action, if too pro longed, or caused by too energetic (stronp;) aolution*, takes tffdct unduly, and often disastrously, at the junction of the tiner tones. We are therefore justified in concluding that this defect, for I do most certaiuly view it as a defect both from the technical and artistic point of view, is not inherent in the paper or in any par- ticular toning bath, but only indicates an unsuitable strength of the chemicals used, and this excess is most probably of the toninr/ ncctfory. I m»an the sulpbocyanide, or acetate, or bicarbonate, or whatever be used. This conclusion is emphasised by the action of the c>mbined toning and fixing bath. For instance, a combined bath, coLtxining, say, Water 5 ounces, Hypo IJ ounces, Acetate of lead IzO grains, Sulpbocyanide of ammonium 30 grains. Gold chloride 2 grains, wiU work in a very satisfactory manner for the first time, but after- wards toning will only take place in a perfunctory manner, the half-tones and less tones changing whilst the deep shades remain about their original colour. The gold having been exhausted to a large extent leaves for the second essay an excess of the toning adjuncts, which are, with the remaining gold, only able to attack those portions of the print where chemical action takes place moat easily. Seeing that a combined bath deposits the gold in so facile a manner, I am surprised to hear it maligned now and again. Used only once, so as never to permit the possibility of the intricate chemical inter-action between the hyposulphite and the acid products of the double decom- position resulting from the toning, I do not see any greater risk of impermanency than with separate baths. It has never been shown that the proportion of faded prints was greater, with the old toning and fixing combined, in the days of plain salted paper, than in later days with what is claimed 'to be the more scientific method. For my part, I should be inclined to expect greater permanenr^y from gold toning deposited upon the fixed image — for that is what a combined toning bath amounts to— than from a gold-toned image afterwards fixed. In neither case can the hyposul- phite dissolve away more than a small part of the reduced silver in the image: but, whilst in the separate baths, the fixing solution may take away what may be described as part of the foundation of the image, viz., that upon which the gold has been deposited ; in the cornbined bath, the fixer robs the image of all the reduced silver which it has the power to do, before the gold is deposited in exchange for the remaining metal, viz., that which the nypj has failed to dissolve. In addition to this, as the prints have to be carried to a further depth in printing for the combined bath, there is an added chance of a greater deposit of metal which may be considered a further guarantee of standing powers. With a "combined bath used but once, and not exhausted by excessive work, I have found no tendency to double colours in gelatino-chloride papers. To economise, only sufficient solution need be used to produce the desired effects. S. ILbbbebt Fay. ♦ ON THE AMOUNTS OF SILVER AND HYPO LEFT IN ALBUMENISED PAPER AT DIFFERENT STAGES OF WASHING. [London and Prorincial Photographic A3«}ciation.] Axv one studying the literature of photography must be struck with the diversity of opi;iion expressed by different workers on the important points of fixing and washing prints, some recommending neutral and others alkaUne hypo, and the strength of the fixing solu- tion varying from five to thirty percent., the length of timj the print should bo washed varying from one to twenty-four hours. The danger of an acid fixing bath and its tendency to yellow the whites of a print, and in addition its doubtful fixing power, whs fir^t pointed out by Mr. J. .Spiller in a paper he read before the I'hoto- graphic Society of Great Britain on January 14, 18tx5. Mr. Spiller in hi.-i paper says that "a hint was thrown out by Messrs. Davanne & Glrard to the effect that the so-called 'pure whites' of the albu- men prints still retained a small proportion of silver in an insoluble condition, and most probably in the form of sulphide." Further on, the author says: " My experiments went to prove that the metal was retained in the whites of the albumen print, and indeed ei2 THE BKITISH JOURNAL OF PHOTOGRA-PHY. [August 11, 1893 in all parts of the coating, in the form of an argentic organic compound, colourless, unalterable by light, and comparatively insoluble in hypo- sulphites and other fixing agents. It could not be a simple sulphide, for the test by which I discovered its existence in the paper was the production of a brown stain upon moistening the white surface with f-ulphide of ammonium." In a paper in the I'hotograpMc News for October, 1862, Mr. Spiller recommended the addition of carbonate of ammonia to the ordinary hyposulphite fixing solution, for the double purpose of preventing by its alkalinity any chemical change or de- composition of the double hyposulphite ; and, secondly, of directly aiding by its special solvent properties in the removal of this organic compound of silver. In carrying out this research, we had two objects in view : firstly, to determine the time the print should be washed ; and, secondly, to endeavour to determine the cause of the fading of the finished print. Three sheets of albumenised paper from the 'same quire were sensitised on a fifty-grain neutral solution of nitrate of silver and allowed to dry in the dark. These were then cut into pieces Si in. X 8i in. The pieces from one sheet were marked A, from the next B, and from the third C. The paper thus cut up and marked was washed for ten minutes in running water till all free silver had been removed. Two of these pieces, taken from different sheets, which could be easily recognised from the letters on the back, were placed on one side, in order to determine the amount of sulphur originally present in the paper and also the amount of silver that had to be removed by the fixing agent. The remainder of the paper was placed in a pint and a half of a twenty per cent, hypo bath ; and, as this gave a little more than two ounces of hypo per sheet of paper, we consider we were on the safe side, as Captain Abney says that one ounce of hypo will fix three sheets of paper. The hypo bath was tested before and after use, and was found to be slightly alkaline to litmus. The temperature was 22'4° C. The prints were kept in the bath with constant changing for fifteen minutes. Two pieces (again from different sheets) were then taken and allowed to drain for five minutes, and the total sulphur- and the remaining silver to be removed by washing determined. The remaining pieces were then placed in a large vessel filled with water and into which water was constantly flowing. The temperature of the water was 13° C. During the first hour the pieces of paper in the water were constantly turned over in order to prevent them sticking. Two pieces were removed at the end of o, 10, 15, 2.5, 40, CO, 90, and 120 minutes, and 19 hours, and the amounts of silver and sulphur remaining in them determined. The estimation of the sulphur and silver in the papers was carried out as follows : — In each case the two pieces of paper were allowed to drain for five minutes, and then torn up into small pieces and placed in a large beaker, with a mixture of 100 c.c. of nitric acid and 200 c.c. of strong hydrochloric acid (free from sulphur), covered with a dark glass, and heated on a sand bath till the paper was completely destroyed. The solution was then taken down to dryness, and 2.50 c.c. of pure distilled water and three drops of hydrochloric acid added, and the whole heated to boiling, allowed to cool and filtered, and the filter paper and beaker washed with boiling water. The filtrate was heated to boiling, and chloride of barium added, which precipitated all the sulphate present as barium sulphate. This was then collected on a filter, dried, and weighed in the usual way, and from this the amount of sulphur present in the paper calculated. The chloride of silver on the filter was then dissolved out with ammonia, and precipitated by means of nitric acid, filtered off and treated in the usual manner. The figures obtained are as follows : — 1. Weight of sulphur in original paper 0050 grammes. 2. „ in water adhering to paper ■0000.32 „ 3. „ in paperfixedbut not washed -2243 „ 4- „ after 6 minutes' washing . . 0063 „ 5. „ 10 „ .. -0045 „ 6- „ II » .•• '0048 „ "• ,. 26 „ .. -0044 „ ^ » 40 » .. -0043 ,^- » 60 „ .. 0046 „ ^0- » 90 „ .. -0047 „ "• " 120 „ .. -0045 „ 12. „ 19 hours „ .. -0047 The amount of sulphur in original paper has been subtracted from results 4 to 12 inclusive. 1 Weight of silver in paper unfixed. . . . •0734 grammes. 2 „ „ fixed but not washed . . '0086 „ 3 „ ,, after 5 mts. washing '0051 „ 4 „ „ „ 10 „ 0035 „ ■5 „ „ „ 15 „ •00^^7 « .- „ „ 5:5 „ -0037 7 „ „ „ 40 „ -0033 8 „ „ „ 60 „ -0036 „ '' ■ „ „ „ 00 „ -0038 „ 10 „ „ „ 120 „ 0040 „ 11 „ „ ,, 19 hours „ -00.39 „ From these figures it will be seen that after five minutes' washing 97-2 per cent, of the sulphur originally present has been removed, after ten minutes 98 per cent., and that, however long-continued the washing, no more of the sulphur can be eliminated. Turning to the silver, we find that as the paper comes from the fixing bath it has lost 88-3 per cent, of its silver ; after washing for five minutes, 93-1 per cent. ; and, after 10 minutes, 95-3 per cent. After ten minutes' wash- ing the amounts of silver and sulphur remain constant. It is evident from the*e figures that the permanency of a print does not depend so much on the washing it receives as "on its tliorough fixing ; and we ai-e strongly of opinion that the best way of removing all the silver is not by using two baths of hypo in succession, but by •washing for about five minutes after the first bath, and then soaking in a second fresh bath of hypo. In what form the silver occurs in the paper, whether as the in- soluble AgXaS„0,j, _ or the soluble Ag„Naj3 S.p^, held in a sort of " loose combination " with the films of the paper, we are unable to state. However, the fact remains that, after a more thorough washing and fixing than prints generally get, -246 of a grain of silver remains in each 22 x 17 in. sheet of paper ; and this, which is probably in the form of hyposulphite in the presence of light and organic matter, is reduced to silver sulphide, and will easily account for the yellowing of the whites of prints after a time. We had hoped to determine the silver and sulphur in gelatino- chloride paper, and the silver in paper that has been treated to several baths of different composition ; but, owing to the length of time required to carry out these experiments, -we have been obliged to defer the investigation of those points for a future occasion. F. B. Gbundy and a. Hadbon. PRACTICAL REMARKS ON PHOTOGRAPHING DIFFICULT INTERIORS. III. In previous articles I referred to various classes of interiors, the photographing of whicb was possible by means of daylight. In numerous cases, however, a worker has to undertake subjects in situa- tions where not a ray of daylight enters, such as dark vaults or underground workings, bonded stores, and many similar places frequently to be met with in all large cities. When such have to be dealt with, some system of artificial lighting has to be resorted to, and, with proper arrangements, made beforehand, and the adoption of a suitable method of illumination, most excellent results are obtained in situations where darkness alone prevails. Somewhat recently it has fallen to my lot to photograph a good many of these subjects by means of artificial light, and I hit upon a plan or system of working that has yielded most satisfactory results. What is known as the modern system of llashlight photography or mode of lighting is not so -svell adapted for photographing large spaces, such as caverns, bonded -warehouses, vaults, &c., as for such subjects as small rooms, or objects situated somewhat near the camera ; but when interiors, such as those having a great depth, as many of the bonded warehouses and other similar classes of subjects often have (for frequently as much as hundreds of yards in length have to be dealt with), then recourse has to be had to a different method of lighting. In undertaking dark interiors of any great extent, one of the chief factors towards success is ventilation, or the obtaining of good currents of air. When such exists, a worker is at once master of the situation; without such, considerable difficulty is liable to ensue. The question of ventilation is most important, and whenever such can be improved, or aided even to the slightest extent, a worker should never neglect to do his utmost to assist in getting up a good current of air. I have known instances, when the atmosphere was dull and heavy outside and no wind blowing, that it was quite impossible to under- take such work in difiicult situations, and a postponement had to be made until not only a windy day, but a day when the wind came August 11,1893] THE BRITISH JOURNAL OF PHOTOGRAPHY. 613 from the dosirod quarter, for not ouly rauat the air curreots be sufficiently pronounced, but they muac be pa«Ned in the proper direction. A very useful little instrument, whicli iu uiv liandM has proved of great value in this work, is the anemomoter. With its aid the faintest current of air can be detected. The reason for so much attention to currents being necessary will become at once obvious to those who understand the necessity of jfuardinff against the overlapping of smoke generated by tlie burning of the illuminating agent or powder. And when it is considered that at times prolonged expos\ires are required even with artificial light, to get which considerable quantities of powder have to be consumed, very large volumes of smoke are thrown off, and, were such to get wafted forward or in front of the lens, the result would be failure. Hence the impoitance of carefully studying the air currents, so that all smoke caused by the burning of the illuminating powder be carried backwards, and thereby not interrupt the vi«w. I have said in some cases prolonged exposures require to be given. By this I mean long exposures when compared with modern ideas of flashlight. In some instances, where deep penetration into dark recesses had to be dealt with, I have burned large quantities of powder in varying situations, the time occupied in the combustion being several minutes. This mean.s largo volumes of smoke being given off, but wlien such was carried outside the field of view no harm resulted. A worker who undertakes this clasa of work should provide himself with several well-formed metal saucers, not too high at the sides ; they are most useful for burning the illuminating powder in, and prevent all possibility of danger from the ignition of the powder. They are very necessary, for in this kind of photography it is a great comfort to be able to feel that, no matter how much slow-burning powder has to be used, or what extent of tiare or blaze takes place, that there is absolutely no cause for anxiety during the time such is blazing merrily awaj'. When all has been carefully arranged before- hand, and an operator knows for certain that there is no danger from fire, the work is done with comfort. On the other hand, if gone about with makeshift arrangements and apparatus, such as burning the powder on a plate or piece of wood, it is just about ten to one, long before the powder has burned itselif out, the worker will have seen something to set up a proper fright, notonly as far as he is himself concerned, but all others who might happen to be near. With proper metal saucers, securely situated, there is no need for fear. I have said that the magnesium flashlight is no use for these dark interiors. After a good many trials I am convinced there is no mixture better suited for prolonged exposures than what Messrs. G. Mason & Co., of Sauchieh all-street, Glasgow, specially supply for this purpose. Of what it is composed I am not aware. All I know is, Mr. Car- michael, so long connected with the chemical department of this firm, has the formulse, and will at any time prepare freshly made up samples for those desirous of photographing by its means. The light yielded is most brilliant, second only to the magnesium : its great fault is the large quantity of smoke thrown off ; but, as I have re- ferred to the manner of driving this outside the field of view, this obi'ection can be set aside. Let me now describe somewhat briefly the iiwdus operandi of photographing a dark vault with the aid of the powder referred to. In the event of the vault being of any great depth, a considerable quantity of powder will be required ; possibly one and a half pounds, divided into three portions of half a pound in each saucer, will not be too much to employ. At the outset it is well to understand that a liberal supply of ammunition is always advisable, and, if it seema that the quantity employed is burning too long, the error is on the safe side, and can be easily remedied by capping tiie lens when the time is judged sufficient. Therefore never stint the supply of powder ; it does no barm, and can lie allowed to burn itaelf out. As a rule, three lights will not be found too much, and, when such are used, the utmost care must be ob.served that they are placed behind the camera, or, rather, in no way in advance of the lens. Very good results are obtained when two side lights are burned at equal •distances apart from each side of the camera a few feet behind the line of the lens, whilst a third is placed on a higher level — say, several feet above the camera, and, of course, somewhat behind it. An ingenious worker will have but little difficulty in rigging up con- venient supports to hold the saucers containing the illuminating powder. A very convenient article to use for the rear centre light is « set of house steps, whilst a few old boxes piled one on top of the other serve admirably for the side lights. It sometimes happens that advantage can be taken of certain situations where lights are capable of being burned in advance of the camera at some distance forward. Care, however, must be taken that such are well screened from the lens, and the light from such only projected forward or on to the side ; in all ca«ea, however, the jmoke must be carefully thought of, guarded against, and currents of air arranged to waft it swmy from the view of the lens. All these arrangements should be judiciou«ly gone about with the aid of lamps or other suitable lights, and, when the camera La brought into play, the focussing should be carefully done with the aid of a lamp, the flame of which makes a capital object to focus on. The lamp can then be moved about, and the amount of view included in the picture easily seen on the ground glass when the lamp is placed on both sides of the view. In all interior work wide-angle lenses are most u.seful, and I hare found that, when using such in conjunc- tion with artificial lighting, a more open aperture in the lens is required than would be the case when operating in daylight ; even with/-16 or/-22, it is almost impossible to over-expose a dark interior when using artificial light. In all cases my best results have been got with the lens working with the fullest possible aperture ; with such a quantity of powder as I have stated, viz., one and a half pounds divided into three portions, the illumination will be very brilliant, and a most actinic light produced from this excellent mixture ; the duration of time which each separate quantity will take to bum varies very little, each portion, if carefully built up in a cone shape in the saucer, will most likely take from forty-five to sixty seconds to burn itself out, and such should yield a fully exposed negative on most dark interiors. Now as to plates. I have recently made a series of tests on ordinary and isochromatic plates, and was .surprised at the difference in results obtained. To get at the best plate to employ I made several exposures with two cameras, under precisely similar conditions as to aperture of lenses; in all cases both kinds of plates were exposed simultaneously to the same light, and the cameras were placed almost side by side. The best results were obtained on fast Lsochromatic plates, backed with asphaltum. The brand I used was Ilford, although it is quite possible other isochromatics would have shown the same result. The difference, however, in favour of the isochro- raatic plate over the ordinary bromide was most marked, and really, in some instances, astounding. In all cases, however, the best results were got when nearly the full aparture of the lens was used. This being the case, the focussing requires especial care ; but, when drawn well forward and the lamp is used to focus by, excellent results are obtained when using a lens that well covers the plate. When all is in readiness for the lights to be burned, it is well to call in the assistance of a couple of friends, and, with the lens uncapped and the shutter of the slide drawn, proceed to deliberately instruct the assistants what to do. I know of no better way of setting liaht to the powder than by the means of the good old fusee; any tobacco- nist will supply a box for a copper. Hand one each (I mean a box full) to each of the assistants, and proceed to say, " Take fusee." They reply, " Yes." Then give the order, " Light fusee." They reply, " Yes.'' Then give the order, " Place fusee in powder," and they reply, " Yes,'' at the same time dropping it neatly on the top of the powder in the centre of the cone. When this is systematically gone about, the three lights will blaze up at the same moment, and second after second irain in intensity, until the vault is lit up in a most wondrous manner, the lights continuing to bum with great brightness for about a minute, according to the quantity of the powder used. And now, at this stage, a worker will appreciate the need of giving some thought beforehand to the ventilation and air currents. Dense volumes of smoke will be thrown off from each light; but, if the currents waft the smoke to the rear, all will go well, and all in front of the camera will be one blaze of brilliant light : but, should by any oversight a door or window be left open whereby the air cur- rents are interfered with and the smoke overlaps forward, all your labour is lost, and the work must be done over again. Some little thought should be given to the position of the lights so as not to cast too dark shadows, but carefully worked out. Negatives quite equal to daylight e.xposures will be obtained. The main points to give need to are first the air currents. Secondly, a liberal supply of powder burned in suitable positions slightly in the rear of the camera. Thirdly, use a liberal supply, and light the diffeient saucers simultaneously. The cone shape of the powder is easily obtained by pressing on the top of powder a cup or basin. T. N. Abmstronq. THE PLYMOUTH COVENTION : BEPOBT OF THE DELEGATES OF THE PHOTOGKAPHIC CLUB. [Read at the Club, Au«iut 2, 1393. J The Photographic Convention of 1893 has come and gone. To sam op its results in a few words, we may say : Socially it hM been a success ; from a photographer's point of view, a failure. 514 THE BKIIISH JOURNAL OF PHOTOQRAl'HY. [August 11, 1893 "WithoDt preciee instructions from the Club as lo our duties, we have conclnded to state our personal opinions for what they are worth, and to give you a brief diary. The actual programme has, doubtless, come before you, the press bavmg given full publicity to it, as also to the ConvenlioD papers. Our part we conceive to be to give yon a personal report. To us the most noticeable feature was a poor attendance. This is a matter for regret. That a gathering which promises and supplies such exceptional opportunities for recreation and intercourse should not be able, out of the thousands of amateur and professional photographers, dealers, Ac, to attract more members, is a matter which merits the serious con- »Bideralion of the Committee of the Convention. We are inclined to attribute much to the date of meeting, and to hold it a cardinal error to have fixed upon one of the busiest weeks of the year, the week of half- yearly accounts, when a majority of business men are intent upon the adjustment of their books. An inconvenient date is not only un- fortunate for those unable to go at such a time, but it is even more so for others who, intending to meet old friends, attend, and are disappointed. There is still another grumble to which, as Englishmen and your dele- gates, we feel entitled. It is the continued folly of attempting to do too much in one week — too much on each day. The Committee should have experience enough by this time to know that photographers do not want a week of hurry-scurry, but a holiday, and also that most photographers like leisure and opportunity to take pictures when they take their pleasures, even if they take them sadly — the pleasures, not the pictures, which, by the bye, is not characteristic of Conventioners. This year the opportunities were too few, and this was the more tantalising because the pictures were there in abundance, and only leisure was required to work. In fact, an 1893 Conventioner's diary might read as follows : — Monday. — Journey down. Pleasant day in train. Gloated over a large supply of plates. Tuesday. — Eoat excursion. Eain saved plates. Wednesday. — Listened to Convention papers. No exposures, bat ex- ercised changing box in the bedroom at night. TAursdai/.— Excursion through fine country. No stops, so SBved plates. Friday. — Good boat excursion. Keaction too much. Shot plates at everything and anything. Saturday. — Rail home with, unexposed plates. Result — Severe economy in plates. And now, abandoning this sad hypothetical case, we descend to the Conventional — one week's work. Monday. — We arrived just in time to dress and rusli to the open meet- ing and reception. This function, honoured by the presence of the Mayor of Plymouth, was held in the Art Gallery, the rooms of which, though small, are suitable and convenient. Here was contained the Exhibition, without which — but for some reason which to your delegates is inscrutable— no Convention is complete. About fifteen firms were represented, and enlargements predominated. There were no noticeable novelties, and it would not have been a matter of any difficulty to select the best exhibit. The Mayor welcomed ns in a hearty speech. Then the general President of the Convention, Mr. George Mason, followed with his address — practical, lucid, and Scotch. Afterwards lantern slides were shown upon the screen. Amongst the exhibitors were Major Lysaght, Messrs. York, Cembrano, Hindley, Welford, &c. , and many of the slides were exceptionally good. After the formal meeting was closed, an informal adjournment of the male Conventioners was made to one of the local hotels. The fragrant weed and social glass, the merry quip, jovial song, and the tall (and still growing) yarn made all present forget that time was flying, and that the pleasant labours of the morrow called for refreshing sleep. Tuesday was to have been the day of days, when, as the guests of the local clubs, who treated us most hospitably, we were to have enjoyed the pleasure of a steamer trip in the waters in and about Plymouth. Unfor- tunately, rain interfered, and somewhat marred the excursion. Still, we adhered to the programme, and it is high testimony to the eiforts of Mr. Hansford Worth, the local Secretary— to the beauty of the surroundings and to the jolly dispositions of Conventioners— that, the rain notwith- standing, we enjoyed the trip. )Vednfsday was devoted to business meetings, photographing the group of members— always an important function witli Conventioners— and the reading of papers. Threatening at first, the weather became finer as the day wore on, and, with its change in mood, Conventioners were drawn away from serious considerations to enjoy the sunshine and the surround- ings. The photographing of the group concluded, and lunch discussed, papers at the Art Gallery became tLe order of the day ; but the Gallery was sultry and oppressively hot, and the attendance of members — never large — became smaller by degrees and beautifully less, whilst the tem- perature rose by tens of degrees. We think that, it the Convention is to remain anything more than a social and photographic outing, the arrangements for the reading, dis- cussion, and reporting of papers at the Convention will have to be revised. Except so far as the publicity of the press is concerned, the meeting for the reading of tlic papers was a fiasco. Too many were attempted ; con- sequently it was a rush against time. The discussions were inadequate, and the reports of the discussions, to our mind, verj- incomplete. Wliy cannot the Convention issue an official report of its own, after the manner of the Photographic Club? On the Wedni-aday evening there was another reception — at Devonport this time— another lantern show, and more papers. The first discussed, a la tea and cofTcc, the papers taken as read, and the lantern show, a lucid interval. Thursday. —Ihe Royal Wedding-day. The favourite excursion was that to Totnes by rail, thence by steam launch down the Dart to Dartmouth, thence by rail to Plymouth. As a ttip to see the country, charming ; but, for photographic purposes, the excursion was disap- pointing. There was no opportunity, save a brief one in Dartmouth after lunch, for taking pictures. Like the restless spirits of which we read in Dante, we were driven at high speed from place to place ; no photographic opportunity was ours. In the evening theie was a meeting for papers, but the Wedding festivities on the Hoe and in the Sound prevailed. Like truth, which is also said to prevail, they were great. The view from Plymouth Hoe is a lovely one at all times, but on this special occasion, with the ships illuminated, bonfires on the surrounding hills, search-lights from the men-of-war in the bay, and jollity all round, the siglit was most impressive. Friday. — Three escnrsions divided the Conventioners. Those who with your delegates decided to visit the Cuttewater Hooe Lake and the Sound had the most pleasant excursion of the whole Convention. Tlie steamer at our disposal was commodious and convenient, and we had ample opportunity of making exposures to our hearts' content ; we thoroughly enjoyed ourselves. In the evening the Convention dinner was successfully carried out. Afterwards music and recitations completed a very pleasant and enjoy- able day and practically brought to a close the 1893 Convention. Saturday. — All excursions were abandoned for this day. This gave us the opportunity to roam about the quaint streets and quays of Ply- mouth as we liked, and we. obtained some of the best pictures on this last day. In brmging our report to a close, we hope to see the Convention strengthened by certain alterations in the arrangements. Besides, the points to which we have already alluded as requiring atten- tion, viz., a more convenient date, an official or authorised report, we think there is still too much attempted in the time at the Convention's disposal, too many items of interest crammed into the week. As regards the excursions, the general Committee might make suggestions to the local Committee embodying the general experience of previous meetings and the requirements of the members. A local Convention Committee must always, and of necessity, be inexperienced as far as the requirements of Convemtioners is concerned, for we meet but once and then pass on. But in the general Committee wisdom must have accumu- lated by now ! In addition, we believe it would be to the general advan- tage of the business portion of the Convention — by which we mean the papers and discussions — were taken all together, de die in diem, instead of being sandwiched, as now obtains, between distracting enter- tainments. And now, in conclusion, let it not be said that we are not grateful for the eiforls made to please us. The energetic Local Secretary, Mr. Hansford Worth, and the local societies whom he represented, are to be congratulated on having beaten record for hearty and well-directed hos- pitality. Towards our Plymouth hosts and friends, if they will permit us the familiarity, we can only have sentiments of gratitude for the suc- cessful efforts which they made to entertain us, and their kindness will ever be one of our most pleasant recollections. We have but one word to add — a member of this Club is the Hon. Secretary of the Convention. Mr. Cembrano is the right man in the right place, and to him the success of the Convention is largely due. We find it a pleasure to be allowed to express what we believe is the universal sentiment amongst Conventioners, hearty thanks for his energetic work in the past, and the hope that he may long ttage-manage our photo- giaphic holiday. August 11, 18a3] THE DUITISU JOUKNAL OF I'ilOTOGKAPHY. filfi We trust, gentlemen, that we have carried out our delegation to yonr eatisfaction, and we hope that next year you will lie able to dinpeiiBe with such services by attending the Dublin Conventiou tn bloc. (Signed) J. Ooaboia, S. HEHiiKnT Fbt. CONFERENCE OF JUDGES OF PHOTOaUiPHlC KXHIBITIONS. The following is an official report of the late meetinR of Judges : — It having been decided by the Committee of Delegates of AfiiliateJ Societies that it was advisable to hold a conference of Judges of photo- graphic exhibitions to agree upon certain linea of action to be followed in judging, and to offer suggestions for the guidance of societies with regard to exhibitions, a committee was appointed to cany out the necessary steps for calling the same together, and a circular letter was forwarded to thirty-eight gentlemen whose names were well known as Judges, and an invitation to attend the meeting was addressed through the columns of the photographic journals to anyone who had acted in that capacity at least four times at open photographic exhibitions. Permission having been obtained from the Council of the Photographic Society of Great Britain, the meeting was duly held on Tuesday, June 20, 1893, at the Society's rooms. No. 50, Great Russellstreot, W.C. Captain W. de W. Abney, C.B., R.E., D.C.L , F.R.S., I'.R.A.S., in the chair. It was at the outset agreed that the decisions should take two forms : (a) Rules which those present should consider as binding upon them- selves, and without the observance of which tliey should refuse to judge; {!/) suggestions, which should take the form of recommendations to committees or other bodies who may have iu their hands the organisa- tion of exhibitions. Both the rules and suggestions were carried in most cases unanimously ; in no case did the minority against any rule exaeod two. (a) Rules. 1. The Judges' decision shall be final. 2. The Judges shall have full power to withhold any award. 3. The Judges shall have power to exclude all persons from the room while judging. 4. The Judges' expenses shall be paid. 5. It shall be stated in the prospectus that the awards are placed in the hands of the Judges, or (It the discretion of the Jwljies. 6. The Judges shall not adjudicate upon pictures exhibited as pro- duced with wares of special trading firms. 7. Pictures which have previously taken awards at open exhibitions shall be classed by themselves. 8. Each picture of a set which has been collectively medalled shall be considered for competitive purposes to have received an award. 9. An award shall be made to one picture only except where, from the nature of the subject, the picture bears an obvious relationship to one another. 10. There shall be no distinction between amateur and professional. 11. No production of any kind whatever from tho sime nega(iast nine a.m., for Alnwick. Leytonstone Camera Club.— August 12, Richmond Park. Leader Mr Aubrey Thomp.son. The Club will proceed by the train leaving Waterloo' L.&S.W.R., at three o'clock, arriving at Richmond twenty-one minutes oast three. Open Social Evenhig at headquarters, eight o'clock. ' Mr. Willia.ms R. Kehnan has taken larger i)remises at No. 41, Graftoa street, opposite Chatham-street, Dublin. Mock Suns. — Mr. M. lilover, of 124, Stepheu's-green, Dublin, writes to. Knowledge, enclosing two photographs of a mock sun which he observed at Dublin on the evening of JuneSOlast. The phenomenon was first noticed about half-past seven p.m., and remained visible for about twenty minutes. The photographs were made with very short exposures, and show the sun's disc seen through cirro-stratus cloud, with a spurious image of the sun also seen through clouds at a distance of about 25° from the sun, aud at about the same altitude above the horizon. A similar image was seen by Mr. Glover ou the left hand of the BUD, but it had faded away before the photographs were taken. "Photographic ENui.iaH 'as She is wrote.'" — The following cu-cular refers to a new French print-oat paper recently put on the market. It is con- ceivable that some French instructions compiled by English writers may read just as quaintly. "With this sensibilised paper, whose manipulation is easy and speedy, you obtain prools giving vigour, depuess. and fineness. Warm hot-pressing, the proofs are more beautiful than those made with albuminized paper. Dry on an ebonite or ferrotype plate, it gives aa enamelled surface. Dry on a depolish glass it gives a dead surface as nice as the jdatina. Every way of virago in use for aristotypique paper can be utilised, nevertheless we> recoiumand the combined virago. You caa preserve it several months iu taking care to keep it off from bgth and dampness, and carefully put it agaiik in the pocket like we deliver it. Do not care of the slight yellow colour that can get the paper, because that desappear to the fi.xage." Messrs. Taylor, Taylor, ftHoBSON write: "Frequently within the last few months we have received complaints of in.struments being sold as of our manu- facture when they proved to be otherwise. In some cases the goods were mis- leading copies of our instrumeifts, and in others they had been represented ati ours through misunderstamling and want of care. It is our unvarying practice to engrave upon every lens we issue our name and address and a registered number, and no lena is genuine unless so marked. Upon such small instru- ments as our circuLir spirit levels, however, on which it is not convenient to do this, we now impress oar newly registered trade mark, of which we enclose an example. This contains the firm's initial, 'T. T. & H.,' upon one heart with a finely engine-turned ground, significant of the precision in mechanical practice which we study to observe. The whole is surrounded by a circle, that which is without beginning or end, a symbol of perfection, which ia our aim. " Sec'retariek of Societies may derive a hint as to subjects for discussion from the following list, which recently constituted the " Question-box " Meeting of the Manchester Amattui' Photographic Society : — 1. In developing a plate, how is it known when the proper density has beeu obtained ? 2. Why should prints from stereoscopic negatives require to be transposed^/. e., left to right ■iiii vice oersd ! 'i. Which is the best backing to prevent halation? 4. How can halation be avoided in interiors and woodland views without backing, and should the plates be over or under-exposed < 5. Does halation ever occur iu films ? 6. 'What quantity of water should be added to a saturated solution of hypo for fixiug («) plates aud [h] prints ' 7. Can any member show how to mount prints without the mountant appearing either upou the surface of the print or upon the margin of the mount / 8. What is a practical way of binencil of rays either before or after transmission through the camera lens, substantially as specified. '2. In the herein-described process, the •mployinent, in combination with a photographic camera, of a refracting plate, having a local lens-like portion, whose curvilinear surface flows or graduates into the plane iurfac« or surfaces of the plate, the plate belog inter- posed in the pencil of rays before or after transmiMJoa through the cam«r» lens, whereby to cause certain of the rays to \w so dertected as to pro.Iace local modification of the image photographed In the camera, snlwUntially M ipecl- fled. 3. In the herein-described process, the employment, in combination with a plane plate of glass, of planoconvex lenses, whose corvatnrss aT» reversed so as to graiper to a lime bath before toning and tixiug, and observe the effect. Mr. H. M. Smith said that he knew of one large firm of portrait photo- graphers who always washed their gelatino-chloride prints in warm water, and their prints had stood for a long time in show cases without showing signs of deterioration. Mr. A. M. Levy said Messrs. Haddou and Grundy's paper seemed to be entirely satisfactory and conclusive, and bore out the statement of Stas that a •great number of silver salts seemed to arrive at a period when you add a quantity of precipitant to the silver salts and no precipitation took place. The only exception was bromide of potassium. Taking the mean of the figures given in the first table, it was ■00-37, and thus we might arrive at the conclusion tliat we had left '0037 of silver in a piece of paper after washing it. There was a strong tendency of some kinds of salts to adhere to paper, and it was difficult to remove the last traces of them ; some alkalies were impossible to remove, cupric oxide precipitated as hydroxide for instance. Silver and sulphur were left iu the paper to react on each otiier. The "action of mass " was favourable to the removal of silv:r, but they arrived at Stas' point that a -soluble compound was not formed, which was probably due to the interfering action of the paper itself. He "thought :i;ost salts couhl be removed by pro- longed washing. Hyposulphite of silver was really soluble, and should not have more tendency to adhere to the paper than; other salts. He shouhl think that if it were really formed they should be able by washing to remove it. Mr. F. B. Grundy thought the "action of mass" might come into play; but possibly the amount of silver was not ajipreciable enough for that action. Mr. Levy replied that there was a mass of hypo compared with the little silver left. A soluble salt was formed which they did not succeed in removing by washing. Was the silver really present as hyposulphite ? Mr. Grundy asked, What else it could be !■ Mr. Levy replied. Why not metalloidic silver, formed in the pores of the paper itself ' Hyposulphite of silverin contact with a porous substance and with air haying every chance of access to it, would most likely decompose, and possibly metalloidic silver and some insoluble compound of silver be formed. The Chairman suggested that it might be possible to ascertain whether the .silver could be dissolved out. Bisidphide of carbon wonid not do for the purpose, as traces of sulphur would be formed by its own decomposition. Mr. Levy said there might be silver in an allotropic form, when it would not be dissolved. Mr. Debenham asked if it would complete the experiment if paper without an inorganic substance were sensitised, and, after fixing with hypo, what was left ascertained ? Mr. Grundy said it was not certain whether the alljumen held the silver, and he had thought of coating plates of glass with it to ascertain whether it was so or not. The Chairman suggested the separation of the paper and albumen and the determination of the quantity of silver left in each and the ratios between the two as a rough method. It would be interesting to repeat the experiments on plain paper. Mr. Haddon said he and Sir. Grundy had that in view, as well as with glass coated with albumen. After further discussion, a vote of thanks was passed to Messrs. Haddon and Grundy for their paper, the latter gentleman incidentally remarking that the experiments had extended over six months, and that several Winchesters of nitric and hydrochloric acids had been used in them. The experiments, if continuously worked at, would have taken at least a fortnight. Northern Photographic and Scientific Association.— August 1, the Presi- dent (Mr. Robins) in the chair.— Mr. F. W. Tevkrsham read a paper entitled the Bacteria found in Water. The lecturer limited his remarks to tlie morphological characteristics of non-pathagenic or innocuous germs, as he believed that Professor McFadyean would, at a later date, deliver a lecture on pathagenic or disease-producing germs. In his concluding remarks, Mr. Teversham paid a high tribute to the excellent arrangements made by the London water companies, who did all that was in their power to supply the metropolis with pure and wholesome water. The Chairman deprecated the practice of passing a vote of thanks to a member of the Association, because, he said, in the first place, it was too formal to be sincere ; and, in the second place, it would tend to convert the Association into a mutual complimentary Society. Nevertheles.s, he felt sure that Mr. Teversham had spoken to a very appreciative audience, who would profit by the lesson they had learnt that evening. Mr. Teversham said he quite agreed with what the Chairman had said, and went on to say that he hoped, at a later date, he would be able to let the Association have thi benefit of any further bacteriological experiments which he had undertaken. An ingenious little instrument, the ellipsogr.ii)!', was exhibited and explained by the inventor, Mr. J. R. Hicks. A patent cat^h for tripods, the invention of Messrs. Spratt Brothers, was also exhibited. It was announced that the next ordinary meeting will be on Thursday, August 17, when some views in Devonshire will be shown. Hackney Photographic Society.— .\ugust 1, Mr. W. J. Hensler presiding. — Members' work was shown from Messrs. Birnes, Cross, Fort. Haukius Hensler, Xunu. Puttock, and Roofe. Mr. Barnes showed a negative, a portrait, which was spotted all over the face. A member suggested tnat it was some incipient skin disease, but it was negatived by having the same spots over the eyes. Mr. Nunn slioweil a bromide paper print develofed with amidol, and asked what caused it to have a yellow tint in places (not stains). No satisfactory reply could be given. Question Box: ■■ What action takes place when an exposed plate is first placed in the alkaline solution on'y, previous to pyio?" Reply: "A mechanical action only, by which the alkali penetrates deeper into the film, so that when pyro is added more detail is en- sured." A case lined with ruby clotli from Messrs. Doublet was shown for storing uutoned prints. Mr. Hensler showed a lantern plate, of which he hail many similar, which, on developing, was veiled over, and which a clearing bath would not remove. It was a special, bought over twelve months ago. Messrs. Cross, Haukius, and Hudson had had the same experience ; no doubt they came from the same batch. A discussion then took place as to in what way our Saturday outings might be improved. Some practical suggestions were made. Brixton and Clapham Camera Club.— August 1, Dr. J. Reynolds, F.R.G.S. (Pi-esident), in the chair.— Mr. Morgan attended on behalf of Alessrs. Fuerst Bros., and gave a demonstration upon the methods of using the new- developers, amidol and metol. He advised amateurs to use the separate developer mixed as stated on the instructions issued by the Company. For bromide work the concentrated solution should be used atnearly its full strength if a black image is required, further dilution giving a cold, grey image. The exposure for plates, &c., should be reduced to half of what would be given were pyro used as developer. Very much over-exposed plates tend to produce fog, but it will be entirely ab.seiit if the exposure is not excessive. In using th"se developers to develop plates, bromide paper, and lantern slides, the members of the Club were pleasantly surprised at the entire absence of veiling and stains. Mr. Morgan stated that the hands will not be stained unless the dry chemical is touched. The solutions may be used over and over again, Mr. S. H. Fry having developed as many as twenty half-plates in two ounces. At the conclusion of the demonstration, a vote of thanks was passed unanimously for Mr. Morgan's thorough explanations of the methods of working these developers, and several members promised to take up amidol and report the result in due course. The next meeting of the Club will be held on August l."i, when the Paget Plate Company will give a demonstration before the members of the Club. Photographers residing in the locality are cordially invited. One of the Committee of Instruction, Mr. Edwards, will be present to answer any questions upon photographic subjects which may be put by any members requiring elementary information, and it is hoped that all beginners will fully avail themselves of the opportunity thus afforded. Botherham Photographic Society.— August 1, Dr. Baldwin (Pi-esident) in the chair. — Good attendance of members. The business included the compe- tition arrangements for present year. It was agreed that there should be classes for excursion work, untouched negatives, prints, lantern slides, most artistic photograph, and hand-camera views. It was announced that the room in the Rotherham Public Museum, placed at the disposal of the Society for exhibition purposes, had been ojiened. The work dis])layed, although some- what hurriedly prepared, had been very favourably spoken of. Sheffield Photographic Society.— August 1, Mr. E. J. Chesterman in the chair. — Mr. B. .1. Taylor and Jlr. E. Beck were appointed delegates to repre- sent the Society on the Council of the Affiliated Societies of Great Britain, after which the prints of the photographic exchange were submitted to a severe but good-humoured criticism, which will, no doubt, lead to good results, aud be for the benefit of the Society generally. FORTHCOMING E.XHIBITIONS. 1893. Septembers "Royal Cornwall Polytechnic Society, Falmouth. W. Brooks, Laurel Villa, Wray-park, Reigate. „ 20-21 *Hove Camera Club. Hon. Secretary, H. Emery, 142, Church-road, Hove, Brighton. „ 25-Nov. 15... ♦Photographic Society of Great Britain, 5a, Pall Mall East, S.W. Assistant Secx-etary, R. Child-Baylev, 50, Great Russell-street, W.C. October 1-31 "Hamburg. Das Ausstellungs Coramitt^ des Amateur Photogiaphen Verein, Schwanenwik, 33, Hamburg. „ 9-Nov. ... "Photographic Salon, Dudley Gallery, Piccadilly, W. Hon. Secretarj- of Organizing Committee, .A. Maskell, 215, Shaftesbiiry-avenue, W.C. Novemlier 7-11 "South London Photographic Society. Hon. Secretary C. H. Oakden, 53, Melbourne-grove, Dulwich, S.E. „ 20-25 "Leytonstone Camera Club. Hon. Secretary, A. E. Bailey, Rose Bank, South-west-road, Leytonstone. Decem'ber "Madras. The Hon. Secretary Amateur Photographic Society, Madras. * Signifies that there are open classes. August U, 1803] THE BRITISH JOURNAL OF rHOTOORAPHY. 019 CotttjEipontrencr. 4V C^yrreapond^nts should n*i'cr iprit* on both »\de9 of tha yiaver, Ho noiict is taktn of communication* unless Che names and addresses 0/ the writers are giwn, TELE.PHOTOGBAPHIC SYSTEMS FOB MODERATE AMPLTFICATIONS. To the Editor. Sib, — It is gratifying to find a communication from another student of tele-photographic systems in your last issue. No one could welcome more cordially than myself suggestions for simplifying technical expres- sions or interpretations of formulip into clear language. My thanks are due to Mr. Hancock for this intention. This eentleman's diagrammatic interpretation of Rule I. given in my paper will serve to impress it upon the minds of all who may interest themselves in the position of nodal points and planes in lens systems. It is needless to say that there are two such points in both positive and negative lenses ; but, as we are concerned with only one in each, for purposes of calculation or the construction of the diagram, the second may be ignored, but their jiositions must be very accurately known and set for practical use. It has already been shown how very powerfully a smnll difference in the separation of the nodal planes affects the equivalent and back foci. Now, if these positions were very accurately marked upon the mountings, and callipers used to set the separation — after which the calculation or diagram were to be made — I venture to think the labour involved in ordinary practice would be considerably greater than the simple measure- ment (i.e., back focus) required in Kules III. and IV. already given. Since writing the paper, I have tried to still further simplify the matter for the average photographic worker who may not have time to devote specially to the study of optics, but who, nevertheless, knows the appear- ance of an image on the focussing screen, and is famihar with the meaning of ''equivalent focus ' and "intensity ' as applied to a lens. In the first place, the foci of the positive and negative lenses, or their ratio, only need be known. In the construction recommended the poeitive is twice the focus of tlie negative. Now screw the lens on to the camera, place the screen at a distance from the back (or negative lens) at least the measurement of the diagonal of the plate used (this in order that the plate may be covered), but as much further away as one chooses. The focus for the chosen position of the plate, wherever it be, |is then always made by the raek-andpinion movement on the mounting. In this manner a choice of the amount of subjects included and its size can be made. \Then this is decided upon, lift aside the focussing screen and measure the distance between its (focussed) position to the cell of the negative lens that projects a short way inside the camera. Multiply this distance by two (as the ratio between the foci is 2 : 1) and add the focus of the positive lens. This is the measurement of the ■' equivalent focus." General Rule to find the Kijuivalent Focua of any Tele-pbotographic I.cns. — Multiply the back focus (chosen) by the ratio the focus of the positive lens bears to that of the negative lens, and add the focus of the positive. We have seen that, when the "ejuivalent focus " is known, the magni- fication and " intensity" of the system are also forthwith expressed. In the case cited in the illustration, back focus = '.)", twice this = 18'; add the focus of positive, G" = 24'' equivalent lens. Thus the magnification is four times, the intensity of the positive lens alone=f-8, and hence, for the chosen extension of camera, the intensity of the teI»ph3tographic system =/-32. Mr. Hinoock makes a slip in the last paragraph but one of his letter anent the intensity of the system. It is true, as stated, that with n magnification of four times a positive element, whose initial intensity is /•8 mii.it become i-3'i ; but Mr. Hancock must certainly not "take it that definition is likely to be unsatisfactory if a larger aperture than f-Si be used," for any shorter extension of camera or back focus can be used, giving greater intensity but less magnification. Again, there is no reason at all that, in the case cited, the positive lens of six inches focus should not have an initial intensity of /-3 ory'-12 for the combination ! The object of the construction of moderate amplification was to make the system applicable to lenses of weaker initial intensity (say,/-S) than portrait lenses, but portable at the same time, as Mr. Hancock readily per- cei-es in the last paragraph of his letter. A lens, however, of high intensity and short focus may have great or weak amplifying negative lenses without unduly adding to their bulk or " necessarily looking like an astronomical telescope ;" and, lor this reason, a " battery " of negatives ini'iht be useful. yuite outside the question of bulk, I have already given theoretical and practical reasons for not employing high magnification to positive lenses of a permanently fixed spherical correction. I think, however, that many will prefer, as Mr. Hancock agrees, to employ one negative with different j extensions of camera, sacrificing magnification to rapidity when necessary, j but making use of a greater degree of magnification when rapidity is not i of such great moment.— I am, yours. Arc., T. R. Dallmkyer. 2-3, ycumfin-$treet, Oxj'o'd street, ))'. ' PHOTO-MICROORArHY. To the Editor. Sin,— In the article in the JounNAT, of July 28, oommentiog on rrofemor Piffard's paper, it is suggested that the obUuning of sharp negative* oi microscopic objects with the objectives in nta twenty-five years ago wa» difficult, in consequence of the want of coincidence of the visnaJ and actinic foci. It is nearly thirty years since I " took up " photography. My first negative was of a microscopic object, and having produced some handredii of negatives of very varied subjects, including objects under polarised light, I found no difficulty arising from the above cause. I worked " in the open," having my lantern at one end of a bench, and the carrier for the plates sliding along it according to the amplification required. The objectives used were cheap French triplets, no eyepiece, but sometimes double concave glasses in front, to increase the nize. The light was " oxyhydrogen," and I got fairly sharp definition up to, say, 400 diameters.— I am, yours, urposes, though it would not be chemically pure. The nearest approach to chemical purity would probably be obtained by converting some Swedish tillering paper into pulp. London, E., says : " When I develop lantern slides with hydroqainone I get a perfectly clear and bright image without any veiling of the lights, but when I use ferrous oxalate, which 1 very much prefer, the lights are^slightly fogged with a kind of white deposit, which seems to be more on the surfacef than in the film. I have used tlie developer with different proportions o iron and oxalate, and also more or less diluted with water. I know it must be the fault of the developer because the same plates are all ri»ht with the hydroquinone. Can you assist me i" The veiling is caused by a deposit of oxalate of lime from lime in the water. If the pictures be Hooded with very dilute hydrochloric acid , it will be removed. One part of acid to twenty or tliirty of water will suffice. E. J. D. writes: "Will you please give me the necessary process to reduce eighteen carat gold in substance to chloride for photographic purposes. Also would the process be different for twenty-two carat gold. I re- member reading some time since in one of your notes that photographers have been known to reduce sovereigns for the purpose, but mine is in small particles?" — Dissolve the metal, in a glass flasl:, in a mixture of one part of nitric acid, live of hydrochloric acid, and three of water with the aid of heat. When dissolved, precipitate the gold with a solu- tion of protosulphate of iron. Wa.sh the i)reoipitate well and then re- dissohe it with the acid as at first, using no more than is necessary. Then dilute with water, so that one drachm of the solution contains hrdf a grain of gold to the drachm. This will form a stock solution or a strength .about equivalent to one grain of chloride to the drachm. OONTBKT8. h.vlation. and methods of pre. VENTINO it Wo fixing and washing silver prints : messrs. gkundy and HADDONS EXPERIMENTS rm INTENSIFICATION WO SUPPLEMENTARY LIGHTING. By EDWARD DUNMORE 508 ON THE CONSTRUCTION OP INTER- CHANOEAULE LENS SCREW FIT- TINGS. Br W. TAYLOR o09 DOUBLE TONES IN GELATINO-OHLO- RIDE PAPERS. By S. HERBERT FRY 511 ON THE AMOUNTS OF SILVER AND HYPO LEFT IN ALBUMENISED PAPER AT DIFFERENT STAOES OF WASHING. By F. B. GRUNDY and A. HADCON 511 Pas* PRACTICAL REMARKS ON PHOTO- GRAPHING DIFFICULT INTERIOF.S. IIL Bv T. N. ARMSTRONG 512 THE PLYMOUTH CONVENTION : RE- PORT OF THE DELEGATES OF THE PHOTOGRAPHIC CLUB. J.OUARDIA *»D HERBERT FRY 313 CONFERENCE OF JUDGES OF PHOTO. GRAPHIC EXHIBITIONS 515 NOTES OS A TOUR IN THE HIMA- LAYAS AND ON THE NORTH-WEST FRONTIER. I. By F.ST. J. GORE, aA. 515 OUR EDITORIAL TABLE 515 NEWS AND NOTES 618 RECENT PATENTS 516 MEETINGS or SOCIETIES 617 FORTHCOMING EXHIBITIONS MS COBBSSFOh'D£NCG , i.9 THE BRITISH JOURNAL OF PHOTOGRAPHY. No. 1737. Vol. XL.— AUGUST 18, 1893. THE KEEPING PROPERTIES OF GELATINO- CHLORIDE POSITIVE PAPER. How long will gelatino-chloride paper keep good, and what are the influences bj which it becomes deLeriorated? It has not yet been sufficiently long before the public to warrant much to be brought to bear upon its keeping proper- ties, but from our own observation, extending to a period considerably over a year, it keeps quite as well as the best ready-sensitised albumen paper, and much better than most of what is procurable. A sample sheet that has been sent to us from the Antipodes, as having gone yellow, has induced us to institute inquiries as to the conditions most likely to promote such discolouration. First of all, we have opened and examined a packet of this paper which was placed in a flat envelope and sealed with ordinary paste, at the time mentioned. This packet has, since its receipt, been kept in a dry room free, in an average way, from gaseous or other deleterious emanations. When examined, every one of the cut sheets which it contained was found to be without spot or blemish, not the slightest discolouration being apparent. From this it is, we think, a fair inference that gelatino-chloride paper does not necessarily become disco- loured for a considerable period when kept with reasonable precautions. By what we must regard as a singular coincidence, a packet ■of ready-sensitised albumenised paper, '■' warranted to keep," was put away at the same time as the other, and with the same precautious as regards preservation. We also opened it, only to find that its contents, six 5x4 sheets, had become hopelessly bad, having passed considerably beyond " the colour of cheese " stage, and hence, quite useless. Exposing gelatino-chloride paper to a damp atmosphere will, we should think, speedily ensure its discolouring, and this with the more certainty if continued for any length of time in a hot climate, or in such hot weather as jjrevails at the present time. This has long been known in connexion with albumen- ised and other paper, and led to the introduction of Marion's preservative case three decades since. This consisted of a cylindrical case with an air-tight cover in which was a small chamber containing dried calcium chloride, which absorbed the last traces of moisture left in the case, and thus ensured the ■dryness of the paper contained therein. We are aware of the discolouration from damp of at least one sheet of gelatine paper which was received in that state on being opened in New Zealand ; but, as other sheets in the same packing-case were good, wo conclude that the initial seeds of decay had been sown on the shelves of the merchant by whom it had l)een packed and shipped. It may not be generally known that the oft-times offensive etfluvium given oflf by albumenised paper conduces to the deterioration of both gelatine paper and plates. Some dealers, from motives of economy of space, or even from orderliness, keep printing papers of various kinds stored in close cupboards, gelatine paper being in immediate contact with albumen paper of foul-smelliug quality. Can it be wondered at if gelatino- chloride paper, redolent of such an atmosphere and taken out to be closely packed up for a voyage of considerable duration to the other side of the tropics, shows indications of discolour- ation when received by the consignees? The wonder would be if it were otherwise. We have been made aware of well-certi- fied instances in which this has occurred. Each one can test this for himself by interpo.sing a piece of non-sensitised albumen paper between two sheets of gelatino-chloride and keeping them pressed in a warm moist atmosphere for some time. Although negative plates ai-e liable to the same action from this cause, it happens that, in virtue of the perfect packing of each dozen, they are but little amenable to injurious conse- quences arising from vaporous emanations by which they may be surrounded. We know, however, that such plates, when they are removed from the packages in which they are sent out and are transferred to a grooved plate- box, have in a very brief period shown signs of having undergone deterioration, more especially so if the plate-box were a new one. Even the emana- tions from the flexible leather hinge, which some time ago used to be so commonly applied to the draw shutter of the dark slide, were well recognised as producing an insensitive strip across any plate which had been left standing in the slide for a length of time. We might expand upon this, but enough has been said to prove that as between sensitive aburaen paper and sensitive gelatine paper the latter has immensely the advantage as re- gards keeping when both are treated alike ; and that, when reasonable precautions are taken for its protection from mois- ture, deleterious atmospheric influences, and injurious vapours, there is no reason why gelatino-chloride or gelatino-bromide paper should not remain qnito good for a time infinitely longer than even its makers would care to assign to it. Gelatino-chloride paper is of only comparatively recent in- troduction, but we possess valuable pictures on gelatino- bromide paper which were exposed and developed between six and seven years after we had received it from the manufacturer. But it had been well preserved from such destructive influences as those here hinted at. .522 THE BRITISH JOURNAL OF PHOTOGRAPHY. [August 18, 1893 MIXED DEVELOPERS AGAIN. As the result of experiments in connexion with the functions of sulphite of soda and alkalies respectively, in conjunction with metol and amidol, some of which were recorded in a leading article a fortnight ago, we have been induced to revert once more to a subject that was treated, though from a somewhat different poiat of view, a few months back. In our issue of March of the present year (page 161) will be found an article ou "Mixed Developers," that is to say, developers in which two or more of the various developing agents are employed in conjunction. This is a practice which has found some favour both in this country and in America, and has for its object the combination of different characteristics not possessed by any one single sub- stance. For instance, hydroquinone is known to act with great clearness and vigour, and to give images of considerable density under favourable circumstances, but it is extremely slow in action, and, with some plates, has an inclination to produce harsh gradations. Eikonogen, on the other hand, is rapid and searching in its astioa, and is remarkable for the delicacy and fine gradation of the images it gives, its fault being that this latter tendency is apt to degenerate into excessive thinness or want of printing strength. By using the two agents in com- bination, however, it has been found that a highly satisfactory compromise is made, and, while the cleanness of working of the two, when used singly, is not interfered with, the density- giving power of hydroquinone is combined with the energy and rapidity of action of eikonogen. At the time our previous article was written we had not made any very extended trials of metol in any form, and with amidol had scarcely attained any marked success in any com- bination, but more recently have been led to take up the sub- ject again, and, we may say, with a degree of success that we had never before experienced. There are, in fact, some special features in the character of the newer developers that seem more espejially to fit them for use in conjunction with hydro- quinone, and our previous failure to derive any apparent benefit from the mixture of that agent with amidol can only be set down to our not having gone the right way about it. The general peculiarities of hydroquinone, as all who have used it are well aware, are its slowness of action and the ex- treme vigour of image it gives. These characteristics are greatly modified, if not altogether removed, if a caustic alkali be substituted fir the fixed carbonates usually employed, while they are greatly intensified by the use of either sulphite of soda or restraining bromide. The extremely powerful modify- ing action of these two substances is, in fact, one of the pecu- liarities of hydroquinone, and, while it is impracticable to alto- gether dispense with them, hydroquinone has come to be re- garded as too slow for ordinary purposes, and more especially useful in cases of over-exposure or for positive work. Amidol and metol, on the other hand, are extremely rapid in their action, and, especially the former, will work without any alkali at all, the soluble alkaline sulphites, as we showed a fortnight ago, playing the same part in conjunction with them that alkali does with pyro and hydroquinone. Moreover although it is possible to employ them without bromide, itjis found, in practice, that the addition of some sort of restrainer is almost absolutely necessary if images of printing density and free from fog are to be obtained. Arguing from these facts, it seemed to us more than likely that if properly used greater advantage would accrue from the mixture of metol and amidol with hydroquinone than those we mentioned in connexion with eikonogen, aad on putting the matter to a practical test we were not disappointed. The way in which we looked at the question was this : — If, as appeared from our previous experiments, hydroquinone would act as the necessary restrainer, then bromide might be altogether dispensed with ; and while the sulphite necessary to confer keeping quali- ties, as the stock solution, would also supply the necessary- developing stimulus to the metol or amidol, as the case may be, any slowins; actiou it might have upon the hydroquinone could be counteracted by the addition of a small proportion of alkali. In ftict, it seemed possible to compound a developer without restraining bromide and with a minimumof alkali, which should be rapid in action even with quick exposures, and at the same time give vigorous images. The merely physical advantages of such a developer, especially in hot weather, are too obvious to nee i mentioning here ; but as we pointed out in our article on " Intensification " last week, it is preferable to get the needful density in one operation; if at all possible there is a palpable gain in that direction. Beyond that, if we consider that users of amidol and metol have hither- to, in order to get density, been using solution containing from sixteen grains of these comparatively expensive salts to each ounce, further heavily loaded down with sulphite, it must be obvious that a great pecuniary saving is effected when the pro- portions are reduced to about one-fourth, and a cheaper sub- stance partly substituted. Such, however, is the not least important fact of the case. As a first experiment, plates were submitted to the action of mixtures of amidol and metol with hydroquinone, without sul- phite, but in the full anticipation of a negative result, as it turned out, the two former requiring the sulphite, and the latter alkali, before development could be set up. An addition was then made of sodium sulphite, and when dissolved this was again applied to the plates, which had been in the meanwhile covered up in a dish of clean water. After five minutes' action, neither mixture had produced a trace of an image, so we con- cluded that for practical purposes the alkali is a sine-qud-non, the hydroquinone, as we had expected, acting as a restrainer. The quantity actually necessary to set up development is, how- ever, extremely small, a single drop from a glass rod in two ounces of solution sufficing to set matters in motion, though naturally rather slowly. When the quantity was increased, in equivalent to two minims of strong ammonia to the ounce, the image at once began to aoq^iire strength and detail, proceeding almost as rapidly as either metol or amidol alone, but without the slight veil that with most plates would then accompany the non-use of bromide. As the plates had received a full exposure, we accepted this as evidence of the restraining power of hydroquinone. After fixing, the image ■ produced by metol and hydro- quinone possessed all the printing density that could be desired, and more might have been obtained by continuing the develop- ment further ; but amidol left something to be desired in this respect. The plates used were specially chosen as being somewhat diflicult to work up to printing density with either ^ metol or amidol. After several trials with different proper- I tions of amidol, hydroquinone, and alkali, it was found that, as in our earlier experiments, no advantage was gained by the addition of hydroquinone until the quantity of that, as well as of amidol, was increased to five or six grains to the ounce. If the former was increased without the latter, density was obtained, but at the expense of gradation, while amidol with iu less proportion of the other substance failed to give any increase of vigour. Aupfust Irt, I8»yj THE BRITISH JOOKNAL OF PaOTOQRAPHY. tA 3 It has been said that a trace of acid acts with amidol or nietol i\3 a better restrainer than bromide, so the effect of an addition of half a grain of citric acid to the amidol solution was tried. The result was a very decided slowing of the action, scarcely, we think, from the slight decrease in the quantity of free alkali present, but evidently the well-known restraining action of the alkaline citrates accompanied by a very remarkable iucreaae of density. With metol, neither the slowing action nor the increase of density was so noticeable, though they were present, not sufficiently, however, to be of any benefit or the reverse. The question next arose as to the most convenient form in which to employ the mixed developer. Many persons favour the "one-solution" form, in which, however, it is obvious that the only control there is — and it is very limited — is in the greater or less degree of dilution. This may answer, perhaps, with one particular brand of plate, and with tolerably accurate exposure, but not otherwise. If the developing and accelerating solutions are kept separate, so that the proportions may be raised at will, there is, of course, much more scope for modify- ing the action ; but the full power of the mixed developer is only attained when all three solutions are kept separate — that is to say, metol, hydroquinone, and alkali. In that case, it is possible at the moment of use to mix the two former in such proportions as will suit the particular kind of plate, or the class of subject imder treatment, and degree of density desired, while the alkali is added to suit the exposure. The power, in fact, gained in thus varying the proportions of the developing agents is one of the most important points in this method. After a large number of experiments, while we are personally inclined to give preference to the separate solutions, we are quite aware that under circumstances the other methods may be more convenient and equally efficient. For instance, in ordinary studio work, where a known plate is constantly used, the successive exposures are all practically uniform, a one- solution developer is perhaps the best, for at all times there can be kept at hand small quantities of alkali or restrainer for use in emergency. The trouble of constantly mixing up fresh solutions is thus avoided ; but, for the run of amateur work, we think the practice of keeping the developer in at any rate two solutions is to be preferred — the developer proper and the alkali — and to use these as circumstances may dictate. Space does not permit ua here to do so, but we hope next week to give briefly formulae of each kind that seem to answer best with different types of plates, naturally thin plates, of course, necessitating different treatment from those which readily run to density. DR. EDER ON THE ACTION OF BROMIDE WITH VARIOUS DEVELOPERS. Dk. Edbr has lately been studying the action of bromide of potassium with various developers, and the results of his in- vestigations are decidedly interesting. Bromide, the most commonly employed of the restrainers, he finds varies in the nature of its effects according to the developer with which it is used. Some developers he points out, are particularly sensitive to the influence of bromide of potassium, iron oxalate, for instance, the bromide used as 1:10, and a few drops of that strength being added to every 100 c.c. of solution, having an energetic restraining action on normally exposed plates. For over-exposed platei it is only necessary to slightly exceed the proportion of restrainer mentioned. Pyro-soda behaves in a similar manner to iron, the bromide acting as a simple retarder ; if, however, pyro nmmonia be used, the bromide acts as a preventive of fog, to the detriment of its powers as a restrainer of development, and it is necessary, therefore, to increase its proportion. For normally exposed plates, Dr. Eder finds, for each 100 c.c. of pyro-ammonia solution, thirty dsops cf bromide solution, 1 : lO, desirable, while for over-exposure it should be added in doses of from 5 to 10 c.c. for each 100 c.c. of developing solution. Hydroquinone-soda (sold in the ready-made form) is less sensitive to the retarding action of bromide than pyro. De- velopment may be restrained therewith by using comparatively large quantities, it is true, but the developer, even with pro- longed use, does not yield such good negatives as pyro or iron. Hydroquinone itself, says Dr. Eder, acts as a species of re- strainer, for it not only develops slowly, but gives vigorous results, not on account of the bromide that may be used with it, but in consequence of its own decomposition by oxidation, the oxidation retarding the growth of the image without tending to impair the vigour of the resulting negative. With eikonogen and metol, notably the latter, bromide acts in the double capacity of preventing fog and restraining deve- lopment, but the retarding eS'ect is less noticeable than with the developers previously named. Very fully exposed plates can be held back by the iise of bromide, but over-exposed pictures, says Dr. Eder, when developed with metol or amidol, are not so well controlled, even with large quantities of bromide, which is unable to check the energy of metol. An old solution of metol — one that has been used several times — - retards development, but does not yield vigorous negatives. Dr. Eder concludes his interesting notes by saying that to metol-soda or metol-potash a slight addition of bromide (I'lOOO) has such little restraining power that the manufacturers them- selves often add bromide to the ready-made solutions, without the user noticing any retarding effect of these developers. The only effect produced is that negatives so developed have no fog. Comet Mamber Two of 1893.— This comet has boon photographed by M. F. Quenisset, and the result communicated to the Paris Academy. It was obtained by means of a Hermagia lens of sixteen cm. (about .'six and a half inches) apertuie and an exposure of forty minutes. The comet shows two tails — one a degrree, and the other half a degree long. Eclipse Photograplis. — In the Ohtervatory Mr. Turner makes some remarks about the August, 1896, eclipse and reviews the photographic results of the late eclipse. He informs ua of one point which appears to us the least satisfactory, namely, that the photo- graphs taken of the corona are in the hands of an astronomer who will make drawings of them. Far better publish the photographs and let them illustrate their ovra story. Mr. Turner heartily congratulates the observers on their performances. Professor Pickering employed one of Dr. Common's twenty-inch reflectors of forty-five inch focus, and used slow plates, the result being that he has got more detail in the inner corona than is shown in the English photographs. Regard- ing the 1896 ecUpse, Mr. Turner points out the importance of making preparations long beforehaod. He says it is not a bit too early to begin at once, for, owing to the position of the central line of totality being so favourable, it is probable that a host of observers, both pro- fessional and aoiateur, will be able to co-operste in the obeervauioBs. 524 THE BRITISH JOURNAL OF PHOTOGRAPHY. [August 18, 1893 Vltra-violet Pliotog'raphs.— VVith regard to these investi- gations by Victor Schumann, before referred to by us, he states that he uses gelatine plates of his own manufacture, as commercial plates are less suitable. " When it is important to support rs far as possible the optical power of photographic spectral apparatus, -where the sharpness of the image is a main condition, also where a strong con- trast in the intensity of the lines is needed, the commercial plate is inadequate. It does not work intensely enough to assist spectroscopy to the extent of the modern dry plate. The gelatine plate of my own preparation gives an intense and finely granular image on a ground clear as glass. The emulsion is relatively rich in silver iodide contain- ing, -with to 100 parts by weight of silver bromide, four to five parts of silver iodide. Its preparation is effected exclusively on Eder's method, silver-oxide ammonia (J. M. Eder, Ausf. Hand. d. Photor/raphie, part iii., pp. 208-211, fourth edition, Halle, 1890), which I have used for more than ten years. For developing the plates I use the aoda-pyrogallic developer, and for fixation sodium thiosulphate." Central Photographic Club.— We gather that the principal reason why the Central Photographic Club has not ere this opened its doors to the several hundreds of members who have joined it is the difficulty which the Committee have experienced in engaging suitable premises. We understand that a considerable number of suites of rooms have been inspected, and in two cases the Committee had come to a decision, only to be disappointed over matters of detail, which rendered it necessary to seek elsewhere. The Committee have now resolved to seek accommodation at a first-class hotel in central London. Negotiations with that object are afoot, and we expect that in a few days the Committee will announce the opening of the Club at some suitable rendezvous, where arrangements can be made for use of meeting-room, dark-rooms, smoke-room, library, i&c, as well as the supply of refreshments and hotel accommodation, with beds for country members. It appears to us that, with such advan- tages, the ultimate possibilities in the way of membership are very great indeed. SKtremely Rapid Sxposures. — Some little while ago we described the marvellous photographs of flying bullets and other . rapidly moving objects taken by Professor Boys; Messrs. E. & L. Mach have been working in the same direction, and have recently communicated a resiimi of their results to the Vienna Academy. Some 1500 negatives were reviewed, and evidenced marvellous results. Images of the Mannlicher bullets, quite sharp and 3J cm. (nearly an inch and a half) diameter, were obtained. Instead of electric contacts made by the flying projectiles which were liable to introduce a dis- turbing element, these experimenters were able to make the bullet itself close the electric circuit mechanically by means of the sound wave it produced. After a number of trials they obtained homogene- ous plane parallel glass plates large enough to produce an interfer- ence field 8 cm. in diameter for use in Ludwig Mach's refractometer. When one portion of such a field is occupied by a flying bullet, an air jet or a sound wave passing an interfering pencil, the interference bands, usually rectilinear, appear bent in such a manner as to indicate a change of density of air at any point. For the purpose of instanta- neous illumination the electric spark was usually employed, but some- times, especially when longer exposures could be made, sunlight rendered monochromatic blue was used. Proposed Photographic Astronomical Telescope for Cambridge University— The authorities of this University have made a public appeal for funds to enable them to construct a new telescope for celestial photography. They require about two thousand guineas in addition to what can be advanced from other available funds, the instrument itself and its fittings, dome, &c., being estimated would cost about £3200. They say, " It will bejallowed that the Cambridge University ought to bo completely eqiupped for carrying on the most advanced work in modern astronomy. As celestial photography is the branch of astronomy in which the most important advance \i now being made, it has been decided that a- photographic telescope shall be obtained if the necessary funds be forthcoming. It is the opinion of those most competent to form a judgment that a photographic refractor of about eighteen inches itt diameter is necessiry to render it possible to obtain results of the highest excellence. The new objective would be corrected for the photographic rays, and the present Northumberland telescope would serve as the- guide when attached to the new tube." That such an instrument would be invaluable for the purpose we are quite certain, and the best hopes of all scientific photographers will go witli the Senate of the University. For those who would desire to convert their wishes into current coin of the realm, we may note that subscriptions will be received by Sir Robert Ball, or by any of the following members of the observatory syndicate: — J no. Peile (vice-chancellor), Ct. (J, Stokes, G. D. Liveing, G. H. Darwin, H. M. Taylor, and SV. W. Rouse Ball. ON THE CONSTRUCTION OF INTERCHANGEABLE LENS SCREW FITTINGS.* Common Method of Gauging Screws. It is customary, in making screws, for opticians to provide them- selves with certain gauges or standards with which to compare their work. Such gauges generally take the form of those shown (not illustrated). Let us suppose that a lens-maker, wishing to do the- thiug -well, seeks the aid of s(jme expert to construct for him a set of standard screw-gauges in pairs, male and female, for each size of screw. He may lieep a duplicate set if he likes, and can afford the luxury. Such gauges may be made of steel ; but, as they would warp in hardening, they must be left soft, and are thus specially liable to become worn. They are put into the hands of the work- man, -who uses them to test his work. When, for example, a male- screw has been formed, he scre-ws upon it the ring gauge. If tha gauge fit stiffly, he reduces the screw until the gauge passes on freely. In this way he tests one screw after another as he makes them, screwing the gauge upon each, and iuevitablj' wearing it away. It is only a question of time, and generally of a very short time, for such a gauge to be -worn large. Suppose it wear only one-thousandth of an inch large on its diameter at the root, or crests, or sides of the threads ; it then becomes possible to pass freely thi-ough that gauge a male screw which may be one-thousandth of an inch too large; But such a screw does not fulfil our conditions of free interchange- ability, and such a gauge, worn even so little, is not capable of en- suring such accuracy as is indispensable. " But," says the workman, " I always make my screws fit the gauge loosely." "How loose?" •we ask. " Oh, so that they shake a bit ! " he replies. This is the common method of gauging screws; only it is rarely the gauges are themselves accurately formed at first. But, even if the gauges are correct, a method like this, which depends for its success upon tlie workman's fancy of the right amount of shake, and which makes things loose to .secure their being interchangeable, cannot be considered an exact and satisfactory method, nor should it be tolerated when we know any better way. Common Mkthods of Ccjttixg Screws. The common methods of cutting screws a-e very simple. Let us take the case of a male screw. The piece to be screwed ia held and made to revolve in a lathe, and its outer surface is turned truly to the form of a cylinder approaching the full outer diameter of the desired screw. Then what is called a comb or chaser is brought into use. This instrument, which may be bought at the shops, is a> cutting tool roughly in the form a common chisel, the working end of which is serrated, the series of alternate indentations and projec- tions presenting exact counterparts of the thread form and pitch of screw which it is desired to cut. This chaser is presented to the re- volving piece of work, and, sometimes by hand, sometimes by machine, it is moved in a direction parallel to the axis of the lathe, so that it cuts a spiral groove along the cylinder and forms it into a screw. The form of the screw thread is determined by the form of the teeth on the chaser. We know that it is of great importance in .securing free inter- changeabilitv that the form of thread be correct, but it is a fact that screws cut by thiscommon method seldom, or perhapsnever, are correctly formed in this respect. A famous navy captain, being asked why, or> a certain occasion, he had not fired a salute, gave thirty-nine distinct • Cenduded from page 510. August IS, 1893] THE BRITISH JOORNAL Of PHOTOGRAPHY. ii2r, and substantial reasons for his neglect. The first reason was that ho had no powder. In thi! same way, fevernl reasons might be given why opticians fail to cut screw.f correctly witli these common chasers; but thi! one sufficient reason Ls that there is not such a tool in the maricet correctly formed. At least I have, never found one, though I tried hard to do so before giving it up and making my own. All the bought chasers I have seen form threads of wrong angle and in- sufficiently deep. Since the prominent points of the chaser teeth come into operation first in cuttin^: a screw, and are tlius most worn away, and since the chasers are themselves cut and formed by tools 1> •Fia. G. liable to similar wear of their prominent edges, we cannot expect very much of the ordinary shop tools, wbicli cost only eighteen- pence j)er pair. And, since everything the workman may do in grinding the tool to sharpen it, in altering the angle of the inclination of its upper face, either by grinding it or by the manner of applying it to its work, tends to alter the form of the screw thread and make it shallow, it comes to pass that the screw threads which are found on scientific instruments generally, and which are nomiimlly of Whit- worth form, vary from a, in fig. 5, which is correct, to b, and even worse than that, which is prepared from measurements of screws furnished to the recent Conference of Opticians by the opticians them- selves. A.v Impb()\ed Fobm of Chaser fob ScBEw-crTTiNO. I have .shown the two principal weaknesses of the common methods 6f screw-making — the possibility of error arising from the inevitable wear of the ordinary solid screw gauges, and the certainty of error ari.sing from the use of chasers which in the ordinary way are faulty. It is now several years ago since I designed a cliaser, shown in fig. 6, which possesses important advantages over the ordinary form. The chasing tool, a, is itself a portion of a screw, with only two turns of the thread, and ia produced in a screw-cutting lathe, a quadrant being afterwards removed to form two cutting edges, one for male and the other for female screws. The figure at b shows also the chaser attached by a bolt to its holder, and in position for cutting a male screw. This chaser has the following important advantages : — The form of its thread is easily measured by means of the test-pieces which I have described. This is practically impossible vrith the ordi- nary form of tool. The circular chaser is ea.9ily made, and the tools used in making it are not subject to that incurable deterioration of form which is inevitable with the tools used in forming an ordinary chaser. The circular chaser is easily sharpened by threading it on a fixed pin or stud, S, as shown in the figure at C,'ao that the chaser may near on the face of an emery wheel always in the same way to preserve the radial position of its cutting faces. It thus retains its original cutting angle until entirely worn away, and, with ordinary care, it is practically impossible to set it wrongly in relation to its work. It may be removed for sharpening by loosening the bolt, without displacing the holder, and in replacing it the only thing necessary is to set the cutting edge at the level of a fixed lino upon the holder. With such a chaser, so easily removed and replaced, there is little temptation for the workman to neglect the sharpening o( the tool, while with the ordinary form this temptation \.-> very great. For want of time I cannot now desorib judge of its composition, or even to examine its detail, we turn it- right side up. As I stand now, I see the President in his chair, and, although the image of him on my own retina is inverted, I know that his head isupand his feet are down; and if I now turn my back upon the Pi-esident, and assume the ungraceful position by benduig my body with my head down between my legs, the retinal image of the President will be reversed, but I have still the impression that his head is up and his feet down. Another instance of the correspondence in the sense of sight and that of touch is demonstrated by a man who shaves before a looking^ glass. Those who are not accustomed to shave are in fear of cutting themselves, for the razor seems to go the wrong way. The same thing is experienced by youn^ microscopists in attempting dissections under a microscope. But it is time we began to consider vision with two eyes, or 630 THE BRITISH JUUilNAL OF PHOTOGRAPHY. [August 18, 1893 binocular vision as it is called. "When we look at an object with two eyes we receive two retinal images, one in each eye, and yet, under normal conditions, only one impression is produced in the mind. We direct the optic axis of both eyes to the one object, therefore they coiverge, and the images, falling upon corresponding parts, are trans- mitted by corresponding nei-ves, which may be described as bundles of fine fil>res, the inside set of whicli cross like the reins of a pair of horses, and are brought together before entering the brain. CONVKBOENCE OK THE OPTIC AxiS. The power of convergence of the optic axis to one point is attained in infancy, and 1 have no doubt many present can call to mind a very young baby before it begins to "take notice" has a very vacant look about the eyes ; it disregards the fond father as he approaches or recedes. The nurse draws her hand over the organs of vision as she notices the baby's eyes sometimes diverge, and this, she says, is to prevent it from having a permanent squint; soon the baby acquires the power of convergence, and then the nurse says baby is beginning to "take notice." But everything is to the baby upside down as yet; very often the bottle gets knocked over, and sundry other things go wrong, the baby begins to turn and twist its little hands about and examine them very carefully; Now is the time the direction of motion is beginning to be learned. Then toys are given, a soft ball, say, which baby throws away and cries for it to be brought back ; no sooner is it restored than away it goes again, and father says it is getting tiresome. Then it hits its little nose, and cries again. Now, the facts are, the baby did not intend to throw away the ball or to hit its nose — things went the wrong way, like the razor to the man who is not accustomed to shave. Later on, other toys are given to the child, which are turned over 'and over; then the sense of touch and of sight are becoming associated, and soon we gain experience. it is by this convergence of the optic axis that we are enabled to estimate the third dimension, distance ; but it will be seen that when we view an object in nature with two eyes the retinal images are not alike, because they occupy different stations, just as if we take a photogragh, then move the camera the distance our eyes are apart, viz., 2i inches, and expose again, the two pictures will to dissimilar ; and it fs by the association in the mind of these two dissimilar retinal pictures that we know from experience we are looking at a solid object or a landscape in nature. If we place two similar objects, say, two billiard balls, in the centre of a billiard-table, and look at them with two eyes, we shall see two balls of a certain size and at a certain distance ; but, if we direct the axis of the right eye to the right-hand ball, and the axis of the left eye to the left-hand ball— which may be done by two tube?— there will be the retinal image of only one ball in each eye, and the mind will unite these as one, and we see them as only one ball ; but, in consequence of the optic axis having little or no convergence, the ' one ball' looks very much further away, and therefore very much smaller. It is also quite easy to concentrate the attention on an image formed in one eye, and to disregard a different image formed in the other eye, as is the case when a microscopist applies one eye to his monocular instrument, at the same time keeping the other eye wide open ; he sees only that which he concentrates bis attention upon (through his microscope) ; this is called the rivalry of the retina. Now, it will be understood that a man with a permanent squint, that is to say, having no power to converge the optic axis to one point, would most certainly see double, if it were not from the fact that he disregards the retinal image of one 6Te,'and consequently he sees no better than a man with only one eye. " This experiment may be tried by rolling two pieces of note paper into tubes, and applying one end of each to the two eyes, at the other end diverging obiects may be observed through either tube, and seen distinctly, but it is impossible to see distinctly through both tubes at one time. " Now we are able to perceive that, although with two eyes we coii- yerge to the same spot and see that spot "distinctly, the indistinct image or out-of-focus parts of the object or of surrounding objects are not alike in each eye, and by falling upon portions of the retina which are not in correspondence these images are doubled, but by being indistinct and our attention not upon them for the moment we do not notice that they are double. Here is an illustration : If I hold my finger, say, 8 inches in front of my nose, and now look at the wall opposite, first with one eye and then the other, there will be certain parts of the wall obliterated in each case because my finger blocks the way, but when I open both eyes there is no portion of the wall I cannot see, notwithstanding that the finger still remains, and the indistinct image of the finger gives me the impression that two fingers are there ; indeed, I really see indistinctly two fingers, but, my attention being upon the wall, ia the ordinary course of things 1 should not notice the finger at all. If, now, we look at a Lo\ on the table with one eye, we get an impression such as a sing'e photograph would produce; with th» other eye we get another view of the box ; when we open both eyes' these different images are by experiencs from infancy associated with what we know to D6 a solid box of a certain size and depth and at a. certain distance. If the box be removed to a more remote position, we see it with lefs convergence, and we estimate its distance by the amount of con- vergence more or liss ; then, if we move two photographs of the box, such as would be seen by the right eye and the left eye separately,, and present these to their respective eyes separately, the mind com- bines the retinal images, and we get the same impression of size, shape, aud distance as in nature, colour, of course, being absent. To do this is the science of stereoscopy. Stereoscopic photographs are, for various reasons, generally taken on one plate by a camera provided with twin lenses and a "division inside the camera, so that we have practically two photographic apparatuses combined in one body. Now, the picture taken by the right-hand lens must be pre- sented to the right eye, and the picture taken by the left-hand lens must be seen by the left eye. And now let us see how this is to be accomplished in practice. SrBnEoscopY in Phactice. We hold a stereoscopic negative in the same position that the plat© occupied at the time of exposure, viz., inverted, with the film aid* away from us the picture taken by the right-hand lens is on our right ; if we turn the negative to get the image right side up, as we say, we find the right-hand picture is now on our left, and a print from the negative would have the same fault. This is caused by the fact that each photographic lens inverted its image independently of the other, and what we have just done with the negative is to re- invert the two together ; and the only way to correct the inversion caused by the lenses is to reinvert the two separately, or, what amounts to the same thing, transpose the pictures. Sometimes this- is done by cutting the negative, and then a single print may be taken from the transposed negative and mounted in the ordinary way as for a single print ; but as there are some delicate points to observe, and as amateur photographers are not usually expert glass cutters, the trans- posing and trimming is oftener done in the prints. In making transparencies on glass from uncut negatives a special printing frame is generally employed by which the right-hand side of the negative is printed on the left end of the transparency plate, then a second exposure is made on the other end of the plate from the left side of the negative, or the same camera and^lens used to take the original negative may be employed as a copying camera, in which case the lenses reverse the negative image independently, and thus transpose at a single operation, or with one exposure. Size of the Pictures. The next thing to consider is the size of a stereoscopic picture, and to arrive at this we must not forget many things that have been said ; we know that the pictures must be observed with no more and no less convergence than would be employed in viewing the natural object or we shall get wrong impressions of distance, and therefore of size, and, as our eyes are only SA inches, or 2|- inches, apart, it would seen» that to be able to see corresponding points in pictures mounted at wider centres a divergence of the optic axis would be necessary ; but by employing slightly prismatic glasses in the stereoscope it is quite possible to combine pictui-es up to 3 inches centres, but any increase on 3 inches is apt to produce a strain upon the eyes and become so painful as to condemn the stereoscope. If 3 inches be considered the limit, it is clear that the pictures, cannot be larger than 3 inches wide. The depth is not controlled by' the same conditions, and may be anything up to 4 inches or more, consistent with the composition of the view or the taste of the photo- grapher. Now, objection has been taken to the smallness of stereo- scopic slides, but tlie objection has no foundation in fact, for it has- been clearly demonstrated on many occasions that when a photograph is viewed at the angle at which it was taken, that is to say, at a distance from the eye of the observer equal to the length of focus of the lens employed to tone the negative, we get the apparent natural fize of the object; thus a 3-inch square picture taken by a -S-inch focus lens, and viewed at 5 inches distance, would convey the same- idea of size as another picture (5 inches square taken by a 10-ihch focus lens, and viewed at 10 inches distance : it follows, then, that if a stereoscopic negative be taken by 5-inch focus lenses, the stereoscope should have lenses of the same focus, for in that case we have the apparent natural size, and therefore larger pictures would have no advantage. Of course, when a picture or a photograph is framed, or even mounted in an album, there are surrounding objects that are- taken notice of, and these may interfere with the retina impressions; AoKuat Id, 1803] THE BRITIBH JOURNAL OP PIIOTOaRAPHY. 631 but by a sterooscope nil surrounding objects ara excluded, we should ■ttea Dothingf but the picture, and for thia rensuii the cird mouots fur jpaper slides Hhoiild be black or very dark in cohur (not to be seen), and when tran^parences on glass are printed they should be bound up •with black piiper marks showin:^ nothing but the actual picture. W. I. CUADWICK. {To be toiUinutd.) NOTES ON A MONTH'S TRIP TO CHICAGO. In those days of ocean travel there is little of interest to record io the short journey across the " berringpond." We embark la one of the tloating palaces, and in a short week find ourselves on terra firma in the New World. If it were not for the general bonhomie of the passengers, short as is the passage across the Atlantic, the voyage would indeed be monotonous. Very few vessels are sighted, and, as one gazes around, nothing meets the eye but sea and sky, and sky and sea. There may be a remote possibility of sighting an icebt-rg, or, as the banks of Newfound- land are neared, where the warm Gulf Stream encounters the cold current from the Arctic regions, an impenetrable mist may envelop the vessel m its clammy sbrould. Then the fog-horn intermittently belches forth its deep, harsh, guttural sound, to the annoyance of all on board, as the •steamer ploughs on its way. The excitement of the passengers grows intense as the land discovered ■by Columbus hoves into view. Even the yellow-faced occupants of r/arious deck-chairs throw off their lethargy and pick up fresh courage at the prospect of ridding themselves of the nausea demon. Soon the vessel crosses the bar and enters the Bay, passing some massive battlements at the entrance. As it steams through the Narrows, between the villa- •crowned shores of Staten and Long Islands, those who possess cameras are busy depicting each point of interest as they are unfolded to the view. Bartholdi's colossal statue of Liberty is soon passed, and the city of New York lies before us, with that marvellous specimen of engineering skill, Brooklyn Bridge, in full view. The ship is soon berthed in one of the docks, which, by the bye, do no credit to an enterprising country like the United States, nor to a city of such pretensions as New York. After the usualcustoms declarations have been made, we land,and, having collected our baggage, proceed to the Customs Office, where, on presenting our ticket, an officer is deputed to overhaul our trunks. (Note. — Don't wait until they come, but get your ticket without loss of time, for it is first come first served here.) The camera is duly investigated, but Eiftcr due explanation it is admitted free of duty. Having consigned our baggage to an express agent, we proceed on foot to the hotel. Two days are spent in visiting the lions of the city. An elaborate system of elevated railways and tramways facilitates locomotion. The pa'ving of the roadways, however, leaves very much to be desired, and the elevated rails, although a convenience, are by no means elegant structures. Besides being obnoxious to the inhabitants of the houses in the streets which they traverse, they are a source of annoyance to the unwary foot passenger, who is liable to be bespattered with hot, rancid grease from the engines of passing trains. Central Park, of which the New Y'orkers are jnstly proud, possesses many attractive features, engineering skill having remedied most of the defects of nature. From New York the train is taken to Philadelphia, and a day spent there. The City Hall of Philadelphia is an immense solid and substan- tially constructed building, reputed to be the largest in the world used as business premises. From the top a splendid panorama of the city and the adjacent country can be obtained. Independence Hall, of historic interest, stands in the heart of the city, and there are some pretty spots worth photographing in Fairmount Park, the largest park in the world. An evening train lands us in the course of three hours at Washington, a city well worthy of its title, the " Queen of Lilies." The site of Washington has been admirably chosen, and nothing could improve the positions of the many fine public buildings it possesses. The Capitol, a magnificent structure in white marble, one of the finest architectural designs in the world, is imposingly situated on a hill over- looking the city, and lends itself agreeably to the art of the photographer. A trip down the Potomac River to Mount Vernon, the home and burial place of George Washington, results in many pretty views being obtained. From the top of Washington's Monument, the highest in America, a splendid panorama of the city, the Potomac River and the distant hills is spread out before us. Two days spent in Washington are hardly suffi- cient to see and photograph everything of interest. Iieaving Washington in the evening, we take the train to Chicago, the objective point of our expedition. The railway traverses the renowned Alleghany Mountains, pa.ssing throngh beautiful mountainous scenery. As it travels on its upward course, valley after valley unfolds itself to view, with distant ranges of blue hUls; now it crosses a mountain stream, then taking a sinuous course at high speed, on the brink of a wooded precipice, until it reaches the highest point 3000 feet above sea-level. Then it gradually descends again, and morning finds us steaming along the banks of the Ohio. Another 'MO mUes or so over flat uninteresting prairie land, and we arrive at Chicago. Everything in Chicago is on a colossal scale, hotels forming cities in themselves, theatres to Mat thoiisan'ls, public buildings and businesi premises towering many stones high that it becomm painlol to look at their summits. The main feature of Chicago U its magnificent bonlevards, and the oit zens may well be proud of them. They trivene miles and mile* of the city, and are lined on either side with piivate dwellings of quite a particular style of architecture which has received the name of Cliicago- esque. A bit of Norman, a bit of Grecian, a bit of the seventeenth century, and then some addition to suit the personal taste of the occupant, and we have it. The Exposition fully indicates the desire of thoChicagoansto do tlungs on a colossal scale. 'I'he immensity and grandeur of the various build- ing are certainly marvellous. For the modest sum (?) of two dollars per dium, a camera may bo taken within the precincts of the Exposition and the photographer will find much to interest and much to amuse him. Tiie varied styles of architecture, the crowds of people of all nationalities, the villages and inhabitants of different countries, the gaily dressed Turk with a strong Hibernian accent, Greeks, Muscovites, Javanese, Esqui- maux, and many others, are all seen under native conditions. It IS truly said that the Americans can build an Exhibition, bnt their management leaves much to be desired. Apart from the catalogue being misleading, the guides who are stationed to direct visitors seem ignorant of the position of the exhibits. I was very desirous of seeing all that was new in the optical world and what improvements in lenses, cameras, and optical lanterns were being exhibited. A diligent search and numerous imiuiries resulted in my arrival at length In the section devoted to same, which is sixty feet above the ground floor and in goch an oat-ofthe-way place that no one would see it casually. To say I was disappointed with the number of exhibits is only repeat- ing what others interested in optical matters have said; and, although the majority of those who were showing photographic instruments are well- known firms whose apparatus enjoys a good reputation, the absence of anything decidedly novel was marked. Perhaps the annual exbibitioos of the Photographic Society of Great Britain and the off-recurring exhibi- tions at the Crystal Palace and elsewhere has made as famdiar with recent inventions, and so there was little left in the way of a surprise for visitors and our American cousins. On leaving Chicago we take a night train to Niagara, as a visit to America would not be complete without seeing the Falls. The first sight of the Falls is disappointing, but their immensity and grandeur gradually impresses one. Here there is plenty of field for the camera, as so many different views can be obtained of the Falls and the Rapids on aU sides. A night train conveys us to Albany, the capital of New York County, from whence we go aboard one of the magnificent river steamers that ply on the Hudson. The Hudson is a grand river, in some places three mdes wide, and the scenery on its banks is very grand. With a long-focus lens many fine views can be obtained, but the vibration of the steamer is not conducive to perfect negatives. New York is reached in the evening and the following morning we board the mail boat on our homeward journey. No difficulty was found in changing plates, the photographers very obligingly allowing use to be made of their dark rooms without any charge whatever. J. J. Stewakd. WALTHAM CROSS. With an intention of catching the 10.25 from Liverpool-street and arriving full early, brought a wee bit of good fortune by getting the one earUer at 10.5, a quicker and better train, reaching the destination with only about two stoppages. Thia train seems much patronized by the followers of the gentle craft. The Great Eastern Railway carry many to the banks of the Lea. Our compartment is very crowded with bundles of rods and fair-sized wood boxes, holding enough to outfit a family iu clothing. Each have more or less length of rope as handles, and generally fitted through with every care to drawers and partitions, all to carry artful devices to deceive tlie bright, lively members of the finny species. While many are gentle in hobby, some are noisy in voice, and far from decent in language. When one reaches manhood's function it is to be regretted he wastes so much breath to so bad a purpose. In his own estimation he may feel taller much, but those not so closely and nearly related may consider him lower, if not very low indeed. At first reaching Waltham Cross, nothing pretty is noticeable only for its noticeable absence. Taking a tnrn to the right from the station, innumerable narrow streams suddenly dart out in all directions, from under bouse windows, beside and under the road, and between rows of houses, all clear as crystal, and alive with small fry. 'The abbey now soon makes its appearance in the near distance — a noble, strong, firm- built'looking structure, standing as it does at the top of the main street. To this hangs a pile of age and history. It made its debut abont 1100, and suffered itself to be knocked and cut about from its original cress shape to its present with seeming indifference, to suffer so much as one would suppose. History of this and the bravo Harold will a tale unfold to those who care to make its reference — and an interesting one, too. Hard by still stand the stocks, fall of ancient carving and memories. 632 THE BRITISH JOURNAL OF PHOTOGRAPH Y. [August 18, 1893 We were assured there is yet a man living near who remembers them in full active use. Beside the abbey stands an inn, and a very old one too. The present liost is a genial man, a good assistant and pilot to the tramping amateur. Half a glance tells him to 1)6 a military man and a man of the world. If you play cricket, and cricket your hobby horse, with him you are at once at home and at your ease. If there is one thing he more glories in than the antiquity of his home and its surround- ings, it's cricket. Feeling our knowledge to be dull on this particular spot, we spoke of photography and our requirements. You have only to leave the old-fashioned room, take three steps, and find the yard all that can be desired. It's been standing so 400 years. It's the old-fashioned coaching yard one sees often engraved, but not in reality; here you have the reality without the engraving. This old house is called the " Cock Inn." You may get one or two views of the yard. Mr. Ward will willingly and pleasantly, if you wish, take you under his wing, and, within a distance of a couple of hundred yards, show you some fine bits and their best points. We saw the effective corners, and felt far from happy. To do them was next to making money for comparison of diHi- culties. The wind saw our desires and groaned and went on much, and that dreadful. When the camera became a standing figure, it raged and became perfectly wild with delight at such presumption. He snatched the focussing cloth and vibrated the camera. We waited, to wait him out. This could not be done ; the more we tried the greater he laughed and became teaeeful, just remaining quiet long enough to consider removing the cap, when he would quickly and carefully place a dense cloud before the shining sun, then allow it to peep through in all its beautiful glory, and in the next turn start the trees wanng their arms in wild pleasure. For one hour we waited, and ate sandwiches, and still he went along as only the wind can, till we confessed our defeat and accepted his least noisy turn and uncapped the lens, recording a little bit of English landscape showing the quaint Harold's Bridge (the oldest in England). The Sportiiifl (iiulDramalic Paper, dated June 30, 1883, gives it as the second oldest, and at the same time a chatty, interesting article, made especially so with eleven sketches of spots round about. Anyway, whether the oldest or its next junior makes but little difference. It's an "old-un " anyway, built of stones, and jolly old stones they seem — ever waiching and keeping guard over a tiny stream of clear, baby innocence, gliding on its ever-moving course, quite careless and regardless of the stern, time and weather-beaten, stone-hearted father bridge above it. The old gateway is in good preservation considering its age, and good for a picture with ruined abbey viewed in the distance. Such bricks ! many measuring 15 inches in length. Our forefathers died with the secret of brick-making, and carried it with them. So bright are they in colour and tough in texture, a lazy Socialist would rather do one class of strike than break such walls as these. By now you may receive slight notice the inner man would prefer some consideration. You once again hie for the " Cock " Inn and its master, where, and by whom, you may be suited to your wishes either in lunch, dinner, or tea. .^fter a comfortable meal and pleasant chat, you away to another direction, working on pictures of another character, consisting of a ruined wooden shanty standing on the edge of the narrow stream, with distant view of small ruined-looking bridges. Many are the different bits of this kind here obtained, that one's half-dozen plates are soon gone, to the sorrow of the photographer. Finding you have pleasantly and quickly passed a few hours, you, with a feeling of strong reluctance, put away your last slide, determined soon to return, possibly with another chum, who may have full play with a roller slide of unlimited exposures : in fact enough — time, tide, and weather permitting — to swallow up all Waltham Cross. ToJi Coan. A DEVICE TO TAKE THE PLACE OP THE CAMERA LUCIDA IN MICROGRAPHY. The art of micrography, or the reproduction on paper of images of minute objects seen through the microscope, says Dr. H. G. Piffard in the Sew York iledicnl Journal, may be practised in variou.s ways, of which the three following are the principal : — 1.— The observer studies the object on the slide, and when he thinks he has the outlines and details, or a portion of them sufficiently impressed on his mind, withdraws his eyes from the tube, and commits the mental picture to paper, using, of tiourge, both eyes in direction of movements of his pencil. Success with this presupposes a retentive memory and con- siderable skill as a draughtsman. 2.— The observer, looking down the tube in the usual way with one eye— for convenience, the left— is, after a little practice, enabled, by a sort of auto-projection, to see an image of the object on a sheet of paper by the side of the microscope. The outlines of this image he traces with the pencil, using the right eye to direct its movements, the observation and the reproduction being simultaneoua. 3. — By the aid of a camera lucida, of which there are many different sorts, a reflected or projected image is visible on the paper with the eye that is at the same time occupied in directly observing tjie magnified image o( the object on the stage. In one of the latest forms of camera lueida — the Abbe — this use of halt the eye for observing, and the other half for recording, is a reasonably convenient method, if the observer's eye is approximately normal ; marked myopia or hypermetropia, and still more jironounced astigmatism, necessitating the use of spectacles, render the use of the camera lacida inconvenient, if not well-nigh impossible. Some time since it occurred to the writer that the practice of micro- graphy could be greatly simpUfied by adopting the principles employed in ordinary projection, as used in connexion with the optical lantern, the' projection microscope, photography, Ac. It was only a question of re- flecting the projected image on to a piece of drawing-paper fixed in some- convenient position. To this end I requested Messrs. Bausch * Lomb to- mount a right-angled, reflecting prism with a short tube extending from one of its square faces, this tube to be of such calibre that it could be^ inserted into the microscope in the place of the eyepiece. From the other square face a similar short tube extends, capable of receiving th& ocular and holding it firmly. When preparing to use this device, the object is placed on the stage and focussed in the usual manner. The microscope is then brought to a. horizontal position, the eyepiece is removed, and the prism case put in its place, the ocular being inserted in the short tube provided for its re- ception. The ocular should point downward. The lamp, or other source of light, should then be disposed in such a way that it properly illu- minates the object to be examined, it being expressly understood that nO' light shall escape toward the observer except that which first reaches the object. A Beck lamp is conveniently adapted to this purpose. If a piece of drawing-paper is placed beneath the ocular, and the room darkened, a brilliant image will be projected on the paper, and its reproduction can be easily accomplished with a maximum of rapidity and a minimum of discomfort. In guiding the pencil the draughtsman uses both eyes, and his spectacles, it needed, and sits in whatever position he finds most comfortable. With a proper lamp, and careful utilisation of its light, this device gives excellent results with amplifications up to four and five hundred diameters. If a sensitive photographic plate be substituted for the drawing paper, an exposure of a few seconds will impress an image that may be developed in the usual way. ♦ ©ur BtJitorial tHahlt. F.vllowfield's Photoobaphic An.nuai., 1893-4. The Annual of Mr. Jonathan Fallowfield is, as our readers are probably aware, an illustrated catalogue of the g^oods manufactured or sold by the firm. When one looks over the 700 pages contained in this Annual, he is tempted to exclaim, ' Prodigious !' and wonder at the fei'tility of invention by which photographers could be enabled to usher into the world such a variety of articles in furtherance of their calling. When we say that there are twenty-four columns of inde.x, it will be seen how unnecessary it is for us to even indicate the contents of such a compendium, which appears to include every- thing. The " Hints," which formed a useful feature in the previous Annual, are reproduced, with some additions, aud form ussful reading matter. In addition to the woodcuts, it contains six nages of auap- shot illustration (two on a page) taken by the " Facile " hand camera. Post free. Is. Adams & Co.'a Photooraphic Annual, 1893-4. Wb are glad to see that Messrs. Adams & Oo. have reprinted in this Annual tne leading articles by various authors which enriched the previous edition. There are certain topics which, when well treated, are useful for all time. In other respects the Annual forms a well- arranged repertoire of the specialities of the firm, numerous pages bein" devoted to cameras for both studio and field work, while of those belonging to the hand-camera family there is a very large assortment, among which the well-known " Ideal " occupies a central position. The variety of apparatus described, illustrated, and priced in this Annual of 400 pages is very great. It is nicely printed on toned paper. Price 6d., post free Is. Photogbaphs FBOst Mb. F. a. Joyner, Adelaidb, Australia. We are always glad to see specimens of the work of brethren at a distance. >Ir. Joyner has sent us some charming examples, showing two children at play with a garden roller. The expression, poaing, and execution are admirable. August 18, 1893] THE BRITISH f)w ^'H,'lT(M;T^A:n^^ nan FnoM Archer & Sons, Liverpool, we have received their supplementAl list of new cameras and appuratus, together with their list of second- hand and soiled apparrttus in ttock. WnATTENs " LoNPOs '" Plates. Messrs. VVbatte.v & \\'ai.n\vrioht, of S-:* (ireat Queen-Street, W.C, have now been making their justly appreciated plates for some- thing lilitf sixteen years, and their jfood qualities seem to have assured them a perennial popularity. As an example of their re- markablo keeping properties, as well as an indication of the length of time sensitive preparatiiins can remain unimpaired in quality, we may mention that some few months back we had an opportunity of trying some plates of the "'Instantaneous" brand that had been made ten years njfo. These, with normal exposure and pyro-soda development, yielded clean, vigorous, harmonious negatives. The plates did not appear to have under^'one the sliglitest deterioration, either in rapiility or good qualities. Samples of the " London " plates (Instantaneous), made recently, were also subjected to trial, demon- strating by their ease of development, and charming ricliness of image that Messrs. Wratten fully maintain their high reputation in the plate making art. ♦ Photooraphic Club.— August 23, Printing on Rough Pajier. XoRTHERX Photographic and Sciestific Association.— Angnst 19 St. Albans. Hackset Photoobaphic Society. — August 22, Photographic Mirrors, by Mr. J. Miller. GospoRT Photoobaphic Society. — August 19, Carisbrooke. Leave Ports- niouth Harbour at twenty miuutes past one. LoNoox .VXD Provincial Photographic Association.- August 21, Olucin tf'id other Xeio Developers, by Mr. L. E. Morgan. Manchkster Amateur Photographic Society. — August 19, BoUin Valley. Leader, Mr. J. Ferguson. Train, Central, thirty-five minutes past one. Croydon Cvmera Clur — August 23, Whole-day Excursion to Forest Row, conducted by Mr. H. Maclean. Train leaves East Croydon at thirteen minutes to ten. Photoobaphic SoaEXv op Great Britain. — Technical Meeting, Tuesday, August 22, at .W, Great Russell-street; subject. Aluminium Flashlight, a deiuoustr.'ition by Mr. Bolas. Leytonstone Camera Clib.— August 19, Along the Roding. Leader, Mr. K A. Golletlge. The Club will assemble at Ilford Station, G.E.R., at thirty minutes pa^t three. Open Social Evening at Headquartei-s, eight o'clock. 23, Special General Meeting to receive and pass new set of rules, and elect Assistant Secretary .and Curator in place of Mr. ilout.igue Atkinson, resigned. Chair taken at eight o'clock. The Queen h.os accepted a copy of the Rev. C. Ctemr Caine's Martial Antv.iU "f the City of York, which was forwarded to Her Slajesty by permission. The last section of the work embraces a review of the life of H.R.H. the late Duke of Clarence ami Avondale during his four years' residence in York Garrison. This book was noticed, with an illustrition, in a recent issue of The British Journal or Photography. Messrs. Morgan and Kidd's Employes. — For many ye.-ivs the employfs oi Jlessrs. Morgan i Kidd Iiave enjoyed au annual holiday together, and on Saturilay, August 5, their extensive jwemises in Kew Foot-road were closed for this year's outing. The members of the party assembled at Teddington Look, and, embarking on the Wintlsor Castle, the largest steam launch on the river, they had a pTeas.ant run up to Hampton. They were receiveil at Hampton by Mr. and Mrs. Kidd, at their charming house] Castlemain, where dinner was served in a lai-ge maniuee erected in the grounds. The tables were beautifully decorated with flowers and palms, furnished from the gardens and conservatories of the house, and were tilled with an extensive and varied array of appetising dishes. About 100 sat down to a verv enjoyable and well-served dinner. The usual toasts followed, and Mr. Kidd, replying to the toast of " Success to the Firm, " said th.it the present year was a very notable one in the history of Messrs. Morgan & Kidd. For some years past he had been solely responsible for the direction of the firm, but at the beginning of this year .Mr. Ernest .Morgan and Mr. H. M. Uennes had been admitted as partners. He hoped thiit the success of the firm would be fully maintained, and that with new blood it wordd receive a still further impetus. Air. Dennes gave a hearty welcome to and proposed "The Health of tlie Visitors," and and -Mr. Erni>t Morgan "The Health of .Mr. and Mrs. Kidd," a toait always very popular. Year after ye.ir the company find tliemselves deeply indebted to .Mrs. Kidil for the active and invaliuible share she invariably takes in the organization of the outing, and her spirited speech in reply to her part of the toast was received with great enthusiasm. After dinner a photograph was taken of the whole p.irty, and the launch was again boarded, and continued its run up the river until Penton Hook was reached. Tea was served on the return journey, and the run back w.as enlived by the diversified musical talent of the members of the party. Most of the songs were rendered in considerably ' better style than the avenge of amateur nWllty, and wwe very heartily received. Teddington was reached about half-pait nine, and a thoroughly eujoynlile holirlay lirought to a close, the whole ii1 the company pronoundng ft. one of the most successful outings ever given liy the firm. RECENT PATENTS. APPLICATIONS FOK PATENTS. No. 14,677. — "Improvements in or rehting to Photographic Cameras." J. B. Ootx. -Dated July 31, 1893. No. 14,839. — '• Improi-ements in or in connexion -with Photographic Shutters, known as Blind Shutters." H. R. Cook.— Ort/c^ August 2, 1893. No. 14,877.—" Improvements in and in connexion with Projecting Lantemn." Complete specification. W. C. HcaaES and H. Vfoot)M:vr.— Dated Augiut 3, No. 14.902. — " Actinometer and Method of Measuring the Chemical Effect of Light." Complete spscirtcatioa. .1. Kp.?.iiZR.—DMetl A ugu.il 3, 1893. No. 14,925. — "Improvements in Photognqihic Cameras and other Optical Instruments." J. W. Gordon. — Dated August 4, 1S9.3. No. 14,927. — " Improvements in Photographic Cameras." E. H. P. Hv^iPHHEyH.— Dated August 4, 1893. No. 15,056.— " Improvements in the Construction of Photographic Camera*.' A. T. LixiK— Dated Avgits! 5, 1893. meettngjEt of Sbocutt^jsi. MEETINGS OF SOCIETIES FOR NEXT WEEK. Date of Meeting. Name of Society. Place of Meeting. August *2l Dundee Amateur „ 21 FUlebrook Atheii.'eum „ 21 Hastings and St. Leonards ... „ 21 Leeds Photo. Society „ 21 Ricbmoud „ 21 Sonth London „ 23 Birmioffham Photo. Society „ 22 Great Britain (Technical) ... „ 22 Hackney „ 22 ! Paisley „ 23 1 LevtonsLone „ 2.3 ' Photograplilc Clnb „ 23 Southpoi-t „ 24 Glossop Dale „ 24. ., 2.1. . „ 21.. „ 24. „ 25.. „ 25.. .. 25- 25.. 25.. 26.. HiUl.. Ireland London and Proviucial . Oldham Cardiff Oroydon Microscopical .. Holborn Uaidstone Swansea West Loudon HuU [ Asso. Stndio, Xetherffat«, Dundee. Fillebrook Lecture Hall. j Mechanics' Institute. Leeds. Greyhound Hotel, Richmond. Hanover Hall, Hanorer.park, 8.^ , Olnb Room, Colonnade Hotel. 50, Gre.1t Russell-st., Bloomsbnry. 206, Mare-strect, Hackney. 9, Ganze-street, Paisloy. { The Assembly Rooms, Hifch-rood. ! Anderton' s Hotel, Fleet4tre«t,B.C. The Stndio, IS, Cambridge-arcadou 71, Prospect-street, Hull. I Rooms, 15, Dftwson.8treet, Dnblin. { Champion Hotel, 15, Aldersfate.«t. I 'The Lyceum, Union.street.Oldham. '; Public H.all,George-street,Croydon. " The Palace," Maidstone. Tenby Hotel, Swansea. Ohiswick School o{ Art. ChUwick. 71, Prospect-street, UiUL LONDON AND PROVINCIAL PHOTOGRAPHIC ASSOCIATION. AuousT 10,— Mr. Thomas Bedding in the chair. Mr. X. M. Levy was elected a member and Mr. J. J. Briglnshavr an honorary member of the Association. Mr. J. Cole showed a hand camera, constructed according to his own design, the principal features of which weref that it could take lenses of from four to nine inches foci, the front of the camera being used as a sky shade, and the rising front being either raised or lowered by means of screw adjustment The nnder is placed lieside the lens, and the camera was fitted with reversing back. Mr. Cole said he was in the h.abit of attaching the camera to hi> waist- co.at by means of a small chain. This freed one h,and and stcidied the camera. E.\hibitions of Members' Work. A question was asked as to whether it would not be desirable to occasion- ally have a Salon Evening, at which member.* would put their best pictures on the walls ! and, further, might not such evenings alternate with the Lantern Evenings I .\fterson)e discussion, Mr. H. M. Smith proposed and Mr. W. E. Debenham seconded, "That it is desirable |to occasionally have a Salon Evening, at which members might ]>ut their pictures on view." An amendment, substituting the words "an E.vhibition" for the words "» SaloD," having been carried, the resolution, as amended, was also carrie>L NiKKO Paper. Jlr. H. M. Smith showed an untoned print on Niliko pajwr. He .said the prints were toned with a hot solution of alum and hypo, which was a very curious toning compound. Such prints had been exposed for two or three months to strong sunlight, and have shown no traces of fading whatever. He asked whether members thought there was anything likely to be hurtful to the keeping cpialities of the pictures in the toning solution I i\Ir. H. Mackie asked : "What was the object of toning the print* I" Mr. SiliTH replied : " To get a warm or sepia colour." 1 534 THE BRITISH JOURNAL OF PHOTOGRAPH V. [August 18, 1893 Mr. \V. E. Debenham had experimented with the action of silver on cotton, rsing silver tartrate, reducing by heat This, on washins, left a reddish colour, which exposure to the vapour of sulphuretted hydrogen chaneed to a rich black. In a fe«' months sulphur-toned deposits became laded and yellow, whereas those reduced by heat stood very much better. ■ . j * Mr. Smith pointed out that a developed image hid stood when a pnnted-out image had faded immediately. Toning built up the developed image, and enabled it to stand exposure to sunlight. Mr. 1'. EvERiTT said that Captain Abney had characterised sulphide ot silver as the most permanent of silver salts. Mysterious MABKrsns OK a Nbgativb. Mr. Everitt exhibited a negative having diagonal wave-like markings of less intensity than the rest of the image. The plate was developed with pyro, to which sulphurous acid had been added. Three plates showed the markings liut a fourth, from the same box, developed with pyro, with the addition ot eulphiteof soda, was free from them. , , ,, , u Mr A. Haddon excursion to Radiett. Members' work wa-s shown from Messrs. Guest, Hensler, Pollard, and Selfe. Question : " What is the 'best method of reduction of a negative overintensitied with bichloride of I mercury and ammonia." Reply: "After ammonia or soda sulphite, rehx the plate with hypo, and it will come out little denser than it was before intensifi- cation. After ayanide of silver, reduce with ferricyanide of potash and hypo. Hypo alone makes little difference. " Mr. Hensler succeeded in removing veil from lantern slides with Farmer's reducer. Mr. Beckett said, if a single unexposed plate is left for any considerable time in its own Ixjx, on ex- Sosing and developing, often the paper mark becomes clearly visible. Mr. lake showed negatives [of a Lilium auratum on isochromatic plates, one with a light yellow screen and the other without ; although two and a half times' exposure was given to the former, yet it had green fog. Three to four and a half times was recommended. Mr. Penny showed a negative veiled over, and asked whether it were chemical or light tog? It was restrained with two or three drops of ten per cent, solution of bromide of potassium. Reply ; "Quarter grain to four ounces is the^correct quantity. Too much soda sulphite was probably used. It is safer to start development with half quantity and increase as necessary." Que.stion : "Can Alpha paper be developed' with amidol and be toned afterwards ?" Reply: "Yes." South London Photographic Society.— August 9, the President (Mr. F.JW. Edward,?) in the chair. — The Secretary .announced the postponement of the President's lecture. Reminiscences of a. Few Eminent Men, which was to take place on September 4, and stated a demonstration of the new developers, A niidol, Melnl, and (//yciK, would be substituted on that occasion. The names of two new members were proposed. Mr. Maurice Howell (one of the Vice-Presidents of the Society) then gave a short lecture on The Chemica'. Action of Intensifi- cation. He stated that intensification was resorted to when the negative was not what it should be through errors of exposure, insufficient development, or several other causes. They, no doubt, all knew how to mercurially bleach the negative, but he proposed to enumerate several ways of turning the white prep,aration into a black one, and giving density to the picture. Ammonium sulphite was almost always u.sed in the old days to intensify collodion pictures, but this process had the bad effect of darkening also the half-tones and entirely blocking np the shoilows. A solution of ammonia or sulphite of soda might be used, but the best of all was ferrous oxalate, because it reduced both the silver and the mercury to a metallic state, and it possessed the best keeping qualities. Ferrous oxalate restored tlie image, and it had another advantage, as the negative might be bleached and intensified over and over again, so as to increase the opacity of the negative, and without apparently injuring it in any way. Tlie mercury chloride could be used again and again until a very heavy FORTHCOMING EXHIBITIONS. 1893. Septembers *RoyaI Cornwall Polytechnic Society, Falmouth. W. Brooks, Laurel Villa, Wray-park, Reigate. ,, 20-21 *Hove Camera Club. Hon. Secretary, H. Emery, 142, Church-road, Hove, Brighton. ,, 25-Nov. 15... ♦Photographic Society of Great Britain, 5a, Pall Mall East, S. \V. Assistant Secretary, R. Child-Bayley, 50, Great Russell-street, W.C. Octolwr 1-31 'Hamburg. Das Ausstellungs Committe des Amateur Photographen Verein, Schwanenwik, 33, Hamburg. ,, 9- Nov. ... 'Photographic Salon, Dudley Gallery, Piccadilly, W. Hon. Secretary of Organizing Committee, A. Maskell, 215, Shaftesbury-avenue, W.C. November 7-11 *South London Photographic Society. Hon. Secretary C. H. Oakden, 53, Melbourne-grove, Dulwich, S.R ,, 23-25 *Leytonstone Camera Club. Hon. Secretary, A. E. Bailey, Rose Bank, South-west-road, Leytonstone. December 'Madras. The Hon. Secretary Amateur Photographic Society, Madras. ' Signifies that there are open classes. €orre]Siionlrence» Corr«spon'i*m(.s sJioiiZi never Myrit^ on both .sii»;.s o/ tha |)oper. Vo notice is taken of ctymmunicati&na uni«s3 the names and addresses of the wri':ers ore given. PHOTO-MICROGRAPHY. To the Editor Sir, — I am afraid that the value of the evidence prodaoed by Mr. H. Woodworth as to the possibility ot producing sharp negatives by ordinary micro-objectives, is somewhat discounted by the fact of liia using cheap French triplets only, my experience of such objectives being that it is impossible they can give a sharp picture ot anything, and consequently, when the image in itself is worthless, a little more in or out of focus does not count. I happen to have been experimenting lately with a variety of the best object-glasses turned out at different periods, and am certain that with the far greater number — not apoohromatic — there is difference enough between the visual and actinic foci to utterly spoil the picture photographically when ordinary plates are used. I read with great interest your article on this subject in the number for July 28, and have nothing to say against the value of the methods there described for correcting the divergence of focus; but, having myself been teaching for some time past how the same thing can be produced without any addition to the objective whatever, will you allow me to give the readers of your valuable Journal my experiences on the subject ? My method is a very simple one indeed, and consists in nothing but substituting isochromatic plates for those not colour correct, and as yet I have not fotmd a lens which will not produce photographically as sharp a picture as can be produced visually, and that without any readjustment of the image thrown on the screen. I may say that I have worked at this subject somewhat exhaustively, Mr. E. M. Nelson having kindly placed at my disposal a selection from liia unrivalled collection of object glasses, and ranging in period from 183(i to 1887. In addition to this, I have experimented on several objectives made since the production of the Jena new optical glass and partly made with it, but without fluorite, and send you a aklection of prints showing the difference ot focus when isochromatic plates are used and when liford ordinary. In all the cases Auffust 18, 1893] THE BRITISH JOUKNAL OF PHOTOGJtAPHY. UK the picture was perfectly true to foons when the former plate wai naed, but more or lens out when the latter. I do not profess to have been the first to discoter the advantage of asing isochromatic plates, but with others the question w*« always mixed up with the use of a coloured screen in conjunction with them, and, as they did not take the trouble to find out what the effect would be withoQt the screen, confused cause and effect, and pat down to the latter what was due to the former. In conclusion, allow me t^ sav that all my experiments were condncted withoDt any screen whatever.— I am, yours, Ac, T. F. Smith. 185, lincknock-road, .V.IC. MESSBS. GBUNDY AND H ADDON'S PAPER. To the EinTOB. Sib, — In your report of the discussion which took place on Messrs. Haddon and Grundy's very valuable paper {ride The British Journal or PnoTooBArBY, August 11, page .518), the remarks I made have been so altered in transcription as to become quite meaningless. I will, with your permission, rectify the text so as to render the report accurate. In the first paragraph is said : — " Some alkalies were impossible to remove ; camtic potash from cuprio oxide, precipitated by that af/ent as hydroxide, for example." (Under- lined words have been omitted.) Second paragraph gtanding under my name : — " Was the sulphur " (not silver, as printed) " really present as hypo- snlphite?" 'Thiid paragraph under my name: — " Why not metalloidic sulphur, formed in the pores of the paper itself? Hyposulphite of soda, in contact with a porous substance, and with air having every chance of access to it, would most likely decompose in a vtry dilute solution, and possibly metalloidic sulphur and some insoluble compound of silver be formed." Fourth paragraph under my name: — " Mr. Levy said there might be sulphur " (not silver, as printed) " in that allotropic form, when it would not be dissolved by carbon di4ul- phkle." These corrections will restore to the passages quoted their real meaning. With reference to the insoluble silver compound formed in the pores of the paper, M. Delafontoine {Wiirt^. Diet, de Chimie, vol. i. page 371) states that both the double hyposulphites of silver and sodium decompose " with the greatest ease " under the influence of heat or water, and yield silver sulphate, silver sulphide, and a sodium salt. With reference to the decomposition of hyposulphite of sodium above alluded to, aqueous solutions of this salt decompose slowly in contact with air, and deposit sulphur. Even when air is excluded, sulphur pre- cipitates in time, and the solution, under the conditions, contains a quantity of neutral sulphite [op. cit., vol. ii., page 1535). The above facts seem to point out that the theory I proposed at the London and Provincial Association, as to the nature of the com- pounds retaining both the silver and the sodium, and unremovable by washing, has, at least, some probability. — I am, yours, &c., Apolphe M Lew. 37, Baaset-road, Ladbroke-groce-road, London, W., August 12, 1893. TELE-PHOTOGBAPHIC SYSTEMS FOB MODEKATE AMPLIFICATIONS. To the Editor. SiE, — Mr. Dallmeyer has been good enough to approve of the spirit of my letter, and to explain the question of rapidity in a manner that should satisfy every one. I did not, however, venture to suggest that definition would be unsatisfactory if a larger aperture than /-32 were used, but only asked for information on this point. My reasons for being a little doubtful about it were these— Ihat, s*ing that the opera- tion of the instrument consists essentially of the formation of an image by a positive lens a certain distance behind a negative lens,but within the focal length of the latter, which image is then enlarged and projected on to a screen by the negative lens, and brought to a focus at a distance corresponding to the greater conjugate focus of the back lens as related to the lesser one, or distance from the lens to the primary image of which the enlargement is made, if the image produced by the front lens is un- satisfactory, the enlarged one must necessarily be so as well. I was thinking at the time of the appearance of images formed with a large aperture, say in bright light — the general biightness of the whole, but an indistinctness of detail, due to the superabundance of light transmitted. Enlargements of pictures such as these could not be satisfactory. Such pictures would be flat, weak, in fact, generally without sparkle. I cannot deny that a large aperture would be useful to some extent in dull weather, but I am afraid the evidence of which I speak would become very appa- rent if /"-S or/-2 were used, or, 8ay,/-12 or f-8 with four times enlarge- ment. My idea is that most photographers would be satisfied with a more moderate equivalent focus, and gain the rapidity by this means. Seeing that the ability to regulate the amount of view incladed would be pre- served, I do not think it would bo necesHary to do mora than construct a lens that would give such a minimum equivalent focns aa would ansure apistureof satisfactory minimum size, with powers to increase the** to an extent that would not overtax tlie powers of the instrument by reducing to aoy important extent the available aperture. It was with thii idea in view that I suggested the use uf a negative lens of lower power than that referred to by Mr. Dallmeyer. Such a lens, say, of five Inches instead o( three inches foons. would require 733 back fonnn to give an equivalent foons of, say, fourteen inches, whereas the ibree-incn lens would give the same equivalent focus with only four inches back focus— insufficient t) cover anythiog but a small plate. I do not offer my figures except aa illustrations of the idea. There are perhaps obstacles which I have not yet encountered that would interfere with the practical lolntion of such a plan, but I must confess that I do not conceive what form they would take. I should Uke to refer to the power of pictorial composition possessed by these lenses in connexion and comparison with their use for photo- graphing objects at great distances. I would myself sacrifice the latter for the former. We have seen the print from a plate of imposing. dimen- sions cut down for the sake of pictorial arrangement of subject, until the pity of working large apparatus for such reduced results hai struck u^ forcibly. Now, the tele-photographic lens will do our print-trimming in the camera, and we can compose our picture in the field instead of with a pair of scissors. This is such a boon to those who would rather take one or two pictures that had demanded and received proper study than a dozen that depended upon more or less ungovernable conditions of appa- ratus, that comment is needless. I must point out that I did not submit my diagram as a method to be followed in the field, its impracticability under these circumstances being evident, but rather to show quickly the actual working of my com- bination, and facilitate the choice of one that might answer special requirements. For a method of ascertaining the back focus only, the following is a very simple plan : Multiply the focus of the negative lens by the number of times of enlargement minus one — thus, by three for four times en- largement, as in Mr. Dallmeyer's original illustration. A division of the result by the actual number of times of enlargement will, by the bye, give the distince of the primary image from the back lens. These cal- culations are only those common to the old style of enlargement-making-, only that an alteration of minus for plus takes place as necessary to the nse of the negative lens. This is, however, only a reversal of the calculation in Mr. D.»llmeyer's Bule III., for finding the extent of magnification, but it appears to me to be simpler than the process which is given in his Rule II. — I am, yours, &c., Charles E. EUxooc-k. 15, Oakfitld-streel , Cardiff. HALATION. To the Editor. Sib, — If Mr. Pettitt's new plate possesses all the qualities he claims for it, it is undoubtedly the plate of the future. For what is halation, but over-exposure and diffusion, caused by a semi-transparent film upon a perfectly transparent basis ? By substituting a non-actinic medium all degradation of the high lights would be prevented, and the beautiful gradations of light and shade seen upon the surfaces in a well-lit studio would be retained ; whereas they are now too generally lost, buried fathoms deep by a multitude of conflicting reflections.- Yours truly, Nyassa, Bournemouth, Hants. Herbert Gus. CELLULOID FILMS. To the Editor. Sir, — I have just been making some comparative trials with films and plates, and would like to know if any amateur who has gone over the same ground has arrived at the same results. I have tried a plate by Schleussner, of Frankfort, against films of four of the most renowned English and American makers, and they all failed, while the plate, with an exposure the minimum of the Thornton- Pickard focal plane shutter, supposed to be less than the ,r>'cs of >i second, with fVi of the Zeiss 111 screw, gave a fair negative, and what is more curious is that a Schleussner film was far worse than any of the others. May it not be that the celluloid has a deteriorating influence on the emulsion, or is it due to the pressure of the sensitive surfaces one against the other in the packing, causing rapid deterioration ? These films all fogged with the same exposure and developer which was used on the plate. — Y'ours truly, Venice, August 12. W. J. Stillman. iExci)ange OTolumn. TitlTet posing cbair» four baclu for quodraplex i»r globe oumeller, ftl»o optlmni «nlargini{ iaat«ni, six-inch condensers, for centUiaear eolargiiw Untora, eight and H qa^rter inch oondansert. Difference arranged.— Ad'Jriz« of a cow or sheep, and consequently he instinctively guesses, without other aid, the aistance of such an object corresponding to the visual angle sub- tended by it at his eye. u. In the case of very distant, but more or less unknown, objects the eye derives much help in judging their distance, and therefore their size, from the apparent thickness of atmoephere which seems to lie between — often a rather deceptive clue. 4. The effects of geometric perspective, especially in the case of buildings and other objects bordered or varied by straight lines. o — -and most important of all in relation to the main point whiih I hope to establish — the effect of what I may call duplex pertpective, due to binocular vision. The view of anv object within 100 yards' distance, presented to one eye, is essentially more or less different in its perspective and proportions to the view of the same object pre- sented to the other eye, the left eye seeing more round the left-hand maiyin of the nearer objects, and the right eye seeing more round their right-hand margins. Examples of the accurate sense of dis- tance derived from binocular vision, and the very vague and shadowy fense of distance derived when binocular vision is either absent or rendered ineffective, are well known to all of us. As an example of the first case, let anybody try to thread a needle with one eye shut. As an example of the second case, how notoriously difficult it is to judge the distance of a horizontally stretched rope without putting the liead on one side, and, consequently, how vague is the idea derived as to the real thickness of the rope. One or two further examples of the fact that our estimate of the size of objects depends upon both visual angle and imagined distance may be given. There is the well-known case of the full moon or the sun generally appearing considerably larger when rising or setting on the horizon than when high up in the sky. Yet it has been conclusively proved, over and over again, that the visual angle subtended by their horizontal diameters is exactly the same in both cases, while their vertical diameters subtend a visual angle actually smaller than when at greater altitude. The only possible explanation of this phenomenon lies in the tact that nearly every one almost unanimously attributes a flattened dome shape to the sky, the parts overhead being thought much nearer than the parts near the horizon, doubtless because there are so many ob- jects between us and the horizon, helped out by the effect of atmo- spheric perspective, all conspiring to throw back the lowest parts of the sky into an apparently very remote distance. Therefore the moon, when setting, although of the same visual angular diameter as when at higher altitude, is instinctively judged to be much further off. and therefore proportionately larger. In the same way a distant hill is judged to be loftier and more im- posing when an atmospheric haze gives the impression of its great distance than when extreme clearness leads to the impression of its near proximity, when it looks comparatively dwarfed in size. Yet the visual angle is the same in both cases. Now, when we come to represent a natural object or scene upon a flat surface, according to the well-established laws of geometrical perspective, which can be done either by the tedious process of careful drawing and plotting out, or, far more expeditiously and accurately, by a rectilinear lens, it must be carefully borne in mind that the resulting view or picture is essentially a monocular one : it ia projected with reference to one particular point of view — the nodal centre of the lens in the case of a photograph, and the }K>int of sight in the case of plotted-out perspective. Therefore, in viewing such a picture on the flat, it is obvious that bin.)cular vision is no longer operative; the picture is the same to both eves, and the effect of looking at it with Iwth eyes is, in the average of cases, rather to make the observer all the more con- scious that he is looking at a flat picture — a fact borne out by 'the habit, common among artists, of viewing pictures with only one eye, whereby relief is gained, and not lost. And, since binocular vision is no longer operative, the observer is deprived of one of the most important means of estimating the re- lative distances of the various objects represented in the view. How- ever skilfully drawn or painted the picture may lie, if it represents objects comparatively near to the observer and within the range of binocular vision (in which case the great relief imparted by atmo- spheric perspective would generally be out of place ), still the principal natural means of instinctively estimating the relative distances of the objects represented is denied to the observer. And the obvious de- duction from this is that those parts of the subject represented which are nearest to the observer will appear somewhat exaggerated in 543 THE BKlTISfl JOURNAL OF PHOTOGRAPHY. [August 25, 1893 size, while those parts f uithest from him will appear somewhat too small. For I have already dwelt upon the fact that tlie mental estimate of ihe size of objects depend upon tivo factors, visual angle and esti- mated distance. Here, then, in the picture visual angles are rela- tively all right, but, owing to binocular vision being inoperative, there is necessarily inability to mentally project the various parts of the subject to their proper relative distances. If it is a full-length portrait of a man seated in a chair, with his hands and feet projecting toward the lens, then, in the absence of binocular vision enabling liim to see at a glance how much the feet are nearer than the body ; they will, therefore, not appear small enough ; in other words, they will tend to appear disproportionately large. And the same thing will happen with the hands and the forward projecting arms or legs of the chair. On the other hand, if one of the sitter's hands is extended away from the camera, then, since the observer of the portrait cannot propurly project that hand to its proper relative dis- tance further back than the sitter, he will inevitably tend to think the hand relatively too small. A very instructive experiment will further illustrate this. Take a low seat a few feet in front of a ^ubstantial arm-chair, in such n position that the back legs are visible between the front ones, and the whole chair seen in somewhat violent perspeetive. Shut one eye, and with the other steadily regard the tout-entemble of the chair. It will be noticed that the foremost parts of the chair bear certain apparent proportions to the more distant parts. On quickly opening the other eye and bringing binocular vision into play, a sudden apparent shrinking of the front parts of the chair at once takes place, thus showing that one-eyed vision is apt to over-estimate the relative wzes of objects near to the eye at the e.xpense of objects more remote. Similar experimeats may be made in the case of other near subjects presenting parts relatively very much nearer to the observer than other parts. But the most decisive experiment of all would be to take a full-length portrait of a sitter placed in such a position in an arm-chair as to bring out this apparent distortion to the utmost — the body reclining, one leg stretched out towards the camera, the other foot put back under the chair ; one hand stretched forward, the other put far back. Let a portrait be taken with a stereoscopic camera, furnishing two simultaneous views of the subject, and taking care that the distance between the centres of the two lenses does not materially exceed the distance between a pair of eyes. Moreover, let the distance between the camera and the sitter be such as is usually found best for artistic results, a wide-angle picture being thus pre- cluded. Yet each picture in itself would be found to give a disagree- able effect of distortion, the foremost foot and hand looking far too large. Let a stereoscopic transparency of the two pictures be made and viewed together in the stereoscope, thus virtually calling binocular vioion into play again, and then it should be found that the apparent exaggerations of the advanced parts of the sitter and chair, &c., at once disappear, everything assuming its proper proportions true to fact ; this taking place not by any modification of the relative visual action (or perspective) subtended by the various parts, but simply because the parts are projected to their proper relative distances, and therefore the twin factor in instinctively estimating real size is supplied. This experiment would supply a crucial test, on which the soundness of the theory herein advanced should rest or fall, and as soon as I can find time I shall carry it out and report upon the result, which I feel positive will turn out as anticipated. This apparent distortion may exist in very various degrees, in some cases being far too slight to strike an untrained eye, but yet glaring enough to an artist, whose eye has been carefully educated to estimate subtle proportions as he sees them, and transfer his impressions to canvas. After all, then, is there anything to be surprised at if artists accuse photography of distortion of proportions ? Where they are wrong is in blaming the lens, whose only error, if it is one at all, consists in being rigidly faithful to monocular perspective. The hand artist has fallen into the way of drawing in the nearer parts of his subject smaller than the laws of monocular perspective would demand, and thus, if he does not overdo it, he compensates in a perfectly legitimate manner for the absence of binocular vision and its conse- quent duplex perspective when viewing the portrait. We habitually use two miniature cameras situated about two and a half inches apart for forming pictures of objects about us, and gauging their relative situations and distances, and therefore relative sizes, and transmitting the information to the brain. The photographic lens justly demands that it should be put on an equal footing with the eye, that its own faithful picture should be supplemented by another picture taken by another lens like itself, but placed two and a half inches to one side, and that the right-hand picture shall be viewed by the right eye only, »nd the left-hand picture by the left eye only, and then no suspicion of distortion can be urged against the combined visual impression. Under these circumstances, nothing further can be urged against photography for portraiture and the like than its scrupulous fidelity to the proportions of the subject as we see them with our eyes. Hence, then, Mr. Van der Weyde's plan of modifying the proportions of his subject by a system of very shallow lenses is but the optical counterpart of the hand-artist's power of compensating in drawing for the apparent distortion following upon the absence of binocular vision, and seems to furnish the only solution of the difficulty of making a flat monocular picture truly represent a two-eyed impression. The only danger lies in the fact that so many sitters are satisfied with nothing short of the most flagrant flattery on the part of the photo- graphic artist as well as the portrait painter, and that the method may, in some hands, be prostituted accordingly. H. Dbxnis Taylor. ♦— AMEPJCAN NOTES AND NEWS. A New American Journal.— The palatial city of Washing- ton, D.C., has not had, so far as we know, a journal to represent photography there until now that the Photographic Adversaria has been published. It is to appear fortnightly, and we give hearty welcome to our young contemporary. The most noteworthy article in the issue for the 5th inst. is one by Dr. Theodore Ilansmann, in which he discusses the possibility of obtaining spirit photographs, and states that in course of his investigations he has obtained several that have been recognised. One of these is printed as an illustration to the article, and represents the author himself, together with a sharply defined portrait of Gen. U. S. Grant on the same plate. Dr. Hans- mann is not quite correct in stating that a certain London photo- journalist, whom he names, lived in Washington ten or twelve years ago. The most that can be said is that he twice visited it for one day, en route for the south, about the time mentioned. Tlie Convention of the American Pbotogrraphers' Association. — If the reports in American journals are to be credited, and we see no reason for not doing so, the recent Convention, which was held at Chicago, has proved a deplorable failure. Not a single paper was read, nor was there any discussion on a technical or scientific subject. In brief, says the Phatographie Times, "the Convention amounted to this only : The members met, selected a location for the Convention next year, elected officers, and adjourned." By the way, the Tiines issued its July 14 number as a special " Convention Number," but quite omitted to say anything about the Convention in it, preferring to give the report a fortnight afterwards. Coincidence or 1 — Is it not due to the readers of the " Convention Number " of the TtTOs^ afore mentioned, that some ex- planation be given how it happens that an article, by Mr. William Taylor, of Leicester, entitled " The Principles of a Lens' Action," should have appeared in its pages with the signature of Walter E. Wood- bury attached thereto? True, the original title of the article has been altered to " The Action of a Lens Simply Explained," and a few verbal alterations, not corrections, have been made ; but, in other respects, the article, together with its illustration, is essentially that of the clever Leicester optician, and forms an addendum to his firm's catalogue. Some explanation seems desirable. On the War Path. — We understand, from the Photo-American, that the Duke of Newcastle, who is stated to have almost a craze for photographing wild beasts, especially those of a rarer class, has visited California along with Mr. Gambler Bolton, intent on his favourite pastime. One project these distinguished photographers have in hand is to photograph the big sea lions at the cliffs. It is not their intention to photograph those creatures from the shore, but to steal up to the seal rocks on a tug and get perfect negatives. After leaving Cali- fornia, they go to Honolulu. We trust that both will return safe to England, heavily laden with the spoils of the chase. Their XiOBS is Our Gain. — The editors of the Aineiican Amateur Photographer announce that, although they lose the active personal aid of Miss Catharine Weed Barnes by her marriage with August 26, 180S] THK BRITISir JOUKrJAr, OS" vHr.Tfw;R4 pmv. Ml Mr. II. Snowden Wanl, and her conaequent removal to London, ■where she will in future reside, yet is she to keep herself in touch with her former journal by still acting as an nssociate editor and Kng-lish correspondent. Thi.s esteemed lady, during her visit to Uritain last year, made many friends, who will gladly welcome her back again, and among these we include ourselves. Kalf- tones In Colours.— Mr. F. Kurtz, of New York, has patented a proces-i of printing half-tones in colours by carrying out the idea of the three primary colours, and using blocks in which the grain runs in lines of different directions. He prints two colours over a third, and thus obtains a combination print in which several different colours appear. The negatives have to be taken through special coloured screens. Friction at the World's Fair.— Photographers appear to be resenting the restrictions put on them in connexion with making use of their cameras at the World's Fair, and are leaving them at their lodgings rather than be subjected to tlie exclusive and restrictive policy adopted towards them. Hence, .'ays the American Amateur, the number who try the privilege is at least ten times smaller than it would be if some reasonable fee was asked, and, as a consequence, the income from fees is disappointing. The annoyances everybody has to put up with at the hands of the Photographic Department are patent and notorious. Extemporislngr a Camera Stand.— There is an absurd rule prohibiting the use of a tripod ; but this seems, in one case at any rate, to have been cleverly evaded by the photographer fixing his camera on the back of a cliair by a bicycle clamp. It is said that the official photographer employs a force of fifteen men to look after camera permits and watch for camera users. Soap-bubble Fhotogrraphs.— In view of the desire that now prevails among some photographers to take children in the act of blowing soap bubbles, Mr. E. L. Wilson gives (in Wilson's Ma(jazine) a formula, presented to the Academy of Sciences by M. Izard. lie uses a resinous soap, made of ten parts of finely powdered resin intimately mixed with ten parts of carbonate of potash, and adding a hunclred parts of water, these being boiled till fully dissolved. This keeps well. For use, it must be reduced with four or five times its bulk of water. The bubbles made with this liquid continue much longer than those made of common soap. THE PHOTOGRAPHIC CONVENTION, 1893. Delegate's Report to the London- and Provincial Photooraphio Association. Is accordance with my duty as an elected delegate to the Photographic Convention of the United Kingdom, I have the honour to submit to your notice the following report, comments, and opinions. By dint of a little personal exertion, I managed to get a small party together on Monday morning, July 3, for the 10.30 train from I'addington. Taking ten tickets, the reduced fares of a party were obtained. The party consisted of nine only, so the amount saved amounted to 7«. lid. instead of 10*. 8(t. each. But, as the remaining ticket was sold at Plymouth, I declared a dividend Is. 'id. each, making the total amount saved 9s. id. I mention this to show what can be done, and to urge the importance in future of some combined effort beforehand — first, to secure a comfortable saloon carriage ; and, second, to reduce the fare of the journey. My work was but a scratch affair at the last moment, but it is certainly an item that should be taken in hand in future, as there will probably always be a goodly London B contingent at all Conventions. The Excubsions. Whilst findin; no fault with the local Committee, there can be but little doubt of the folly of arranging too many excursions for one day. At Plymouth, as at Edinburgh, the great majority went to one particular fixture, leaving a bare hmdfnl for the others. This must be particularly unpleasant for the leaders of both, or, as wai the oaae at Plymouth, all three. Two or three of those arranged thi« year practically fell throagh altogether, and it should be a lesson for next year that the alternative ezoursioDB ahoald not exceed two apon any one day. I will mention on* instance only. The excursion to Looe and the Cheesowring on the Thursday was allowed to drop, with the result that the one to Totneii and down the Dart was patronised by nearly seventy instead of about twenty-five as expected. The consequence was that the flotilla down the Dart had to be augmented, and finally consisted of the steamer, a barge and two small boats. To me the pleasure of an excursion is the party, and therefore all arrangements for catting np a good size gathering into fragmentary segments of five or six do not commend themselves. The weather, with the exception of the first day, was particularly bright and p'easant, though hardly the best for photographic work. It was most unfortunate that the first day wa3 so wet, because the special invitation steamer trip organized by the local committee was quite a new thing, and deserved greater success. By means of local subscription, a handsome steamer was chartered for the whole day free of cost to those attending the Convention. Had the day been fine, the chances of the hand camera were simply magnificent. However, Mr. Handsford Worth, the local Hon. Sec, and Colonel Barrington Baker exerted themselves to the utmost, and their endeavours, together with the two excellent repasts served on board, the music, and collection for the Photographers' Benevolent Association fund, served to keep the large company in what, under such depressing circumstances, might fairly be termed good humour. The trip which was probably more enjoyed than any other was that down the beautiful river Dart from Totnes to Dartmonth, although there was but little photographic work feasible. The Papers Read. I fear in this instance that I must find serious fault. There were too many papers to commence with, some of them were not conducive to discussion at all, and there was no time in any case for it. It was rather surprising to me that, beyond the ofiicials, who would feel compelled to attend the reading of the papers, even a small number of ordinary mem- bers put in an appearance. The papers are usually in print and handed round beforehand to the meeting, so that there is not even the charm of listening to something new, and the discussion, being so limited, is of no value. Consequently there is but small inducement for members ta attend when varied enjoyments await them elsewhere. The highly scientific nature of some of the papers is distinctly against any sort of discussion. Even the ablest scientist would fight shy of dealing with a mass of diagrams and tables without first digesting them. The Social Side Was, as usual, distinctly a success. Old friends met old friends, and newer members met those they had so often heard of or read about, but never seen in the flesh. With the slight exception of a little snarling by one or two members of the trade, everything passed off well. The post- convention meetings, where over a glass of stone ginger bser, o'd battlei are refought, and song and story enliven the evening, have bacome quite a recognised institution. One of our members, Mr. Cowan, rendered yeoman services at these with his recitations. To sum up, the Convention, in spite of the few matters which might be improved, was enjoyed by every one, and I hope Mr. Cowan or Mr. Haddoa will bear me out in this. And I should like to recognise the valuable services of Mr. Handsford Worth, the local Hon. Secretary, who was mos indefatigable in his efforts to please and assist ; also those of Mr. Cembrano. They are both model Hon. Secretaries. One more grumble and I have done. The receptions by the Mayors of Plymouth and Devonport were all right in their way, but I muit ':ertainly deprecate the increased use of evening dress. This year the number of times required was increased to three. Personally I should like it to be forbidden altogether. We don't go out photographing and for enjoyment in dress suits ; and, when the local committee speciallv st iteJ on the programme that they should make a point of attending the receptions in morning dress, it was nothing less than affectation for the visitors to disregard the hint. Of coarse it's just as well to show the natives that some of as possess such articles of clothing, and that we know how ta walk about the streets to show them to best advantage. A journalistic friend of mine, bearing of the new venture, the magazine I edit, said, "Oh, it's easy as easy; when you haven't much to say, shove in more pictures." This is my case now, and in the album in which this report is written you will find a few of my hand camera shots, to make the report a pictorial souvenir as well. WALriB D. Wsiroav 544 THE BRITISH JOURNAL OF PHOTOGRAPHY. [August 2'), 1893 CAMERA SUPPORTS. Fob years alight, portable, withal rigid, stand has been a desideratum. I have longed for such ever since my first essays, when 1 was wont to carry some five feet or so of ash and brass, yclept a tripod — nothing was better in its was, stronger or more rigid ; the stand bearing the name of the the late Mr. Kennett was, and is, admirable, but weighty ; the " Maudsley " is a model of beauty, and is light, neat and rigid, the perfection, in fact, of a tripod for general use. The large variety of stands may be somewhat confusing, they may be all that could be wished as regards ingenuHy, but, when we come to consider their portability, opinions will vary ; what one man looks on as portable, another would consider impracticable. I once owned a " fishing rod and gas-pipe arrangement " of metal with a horn attachment, this was supposed to represent an umbrella. It required a strong arm to wield it, was only some three feet six inches high when extended, and was then practically of no use, being a veritable reed " shaken with the wind." However, the ordinary photographer has little now to complain of with regard to tripods, he can get them one, two, three, or four fold — but none of these are suitable for those who, like myself, combine the art science with cycliny. I believe the want of a good stand deprives many cyclists of the pleasures derived from the practice of photo- graphy. To such I commend the perusal of this short note and description of what I have so far found to be a really light, portable, and rigid contrivance for supporting a camera during exposure. My own idea was, to have made a hinged rod to attach to the handle bar of safety, the rod to have at the end a metal plate pierced for the camera screw and fitted with a universal joint. However, I saw just in time a really good attachment by Lancaster, which, though not, I think, perfect, is still so near the mark as to make it, considering the reasonable price, a good thing to have. Xow, what we want on the cycle is an arrangement which will enable us to dismount, and, without any unpacking, transform our machine into a steady tripod, the time expended being merely that required to unpack and erect the camera, entirely doing awav with any bulky bundle of sticks strapped to the frame of the bicycle. With the camera attachment referred to (Lancaster), and a simple contri-ance which any one could manage for himself, we have all we require. The cycle, of course, will be of no use without a third " leg " or support. This I get by attaching to the safety frame, just above the front fork, by means of a collar and nut, a light bamboo stick. This, when not in use, is held up under the saddle with a small strap, though a spring " clip " would be simpler. Drop this " leg '' down, and we have at once a strong, steady stand, the safety leaning over somewhat. The camera attachment, being already fixed to the top bar of frame just bshind the handles (the Beeston frame being understood), is at once ready ior the camera. We get three movements — lateral, vertical, and horizontal. Each movement is controlled by a simple but powerful screw, and the whole arrange- ment in situ is barely noticeable. The total weight of attachment is well under one and a half pounds. The height may be reckoned at from three to four feet six, the rapidity being wonderful. It is well, however, to remember that to secure the best results, and to ensure one's own comfort, the camera and its fittings must be per- fect. Each part should move freely and easily, the dark slide inserted and the shutters drawn without undue exertion. This is on the face of it a simple matter, but is most important in practice. Above all, the exposure should invariably be made by means of a mechanical arrangement fitted with ball and tube ; the focussing cloth, slightly weighted at the comers, is left hanging, and leaves no necessity for touching the camera or machine during exposure. It is by no means requisite to remove the camera every time between exposures, as where several views are to be had in one neighbourhood the machine may be wheeled or ridden, the camera being in place ready for work ; at the same time all unnecessary vibration is to be avoided. Many cyclists may prefer to add (with verv slightly increased weight) a second leg or strut, i.e., one each tide of bicycle. This gives greater steadiness, takes no more time to work, and is un- doubtedly an additional security against vibration. Another point worth mentioning is to line or pad the clip with leather ; the latter is hotter than rubber. It may be securely fastened on with Front's glue. 1 aking the metal hot, running in the glue, adjusting the leather and s rawing up tight till secure and set. j, Pikb, PLATINOTYPE. [North London Photographic Society,] Thkrb are, to my mind, but two other processes able to approach platino- ^'w^'i^'u" P^otoS'a'ure and carbon printing. As to the exact salts with which the papers are coated, I believe the chloro-platinite of potassium, in combination with ferric oxalate, are chiefly used. Ferric oxalate is sensitive to light, and by tlie action of light becomes fen-ous oxalate. One of the properties of ferrous oxalate is, that in solution it has the power of reducing ehloro-platinite of potassium to metallic platinum. Oxalate of potash, or kindied alkalies, which compose the developer of these papers will dissolve ferrous oxalate, and this in turn reduces the ehloro-platinite of potassium to metallic platinum, forming the image of a platinum print, the unused portion of the iron salt being dissolved out by the acid bath. The foregoing brief outline of the process shows the extreme simplicity of this method of printing. Platinum is undoubtedly one of the most stable and unalterable metals known to chemists, and in the very fine state of division in which we find it in a platinum print is of a rich, pure black, unaffected by light and insoluble in hydrochloric or other acids, thus ensuring permanency. This quality is undoubtedly of high value, though its simplicity of working, its artistic colour, and the soft effects producible by it, quite overshadow, in my estimation, all other good qualities. To obtain an artistic print by any process, it is neces- sary to devote considerable study to the production of the negative most suitable to it, and the samples which I have here will, to some extent, ex- plain the quality of negatives most suitable to the process under considera- tion. True artists admire a perfect platinum print as a thing of beauty in monochrome, while it is the envy of the mediocre painter who daubs on the canvas his abominable greenery-yellowy colours in sections like a child's puzzle, which colours externally refuse to blend together and can only be softened down by prolonged contact with the fuliginous atmosphere of the kitchen chimney. Some of the older generation of photographers were somewhat incensed at Mr. Guardia's remarks at the Plymouth Convention, re art productions with the hand camera, and claimed that equally good work was done by some of the early and earnest workers as by those of the present day, and that is undoubtedly true ; but. however technically perfect their collodion negatives with their false shadows of absolutely clear glass may have been, and probably were, the photographers of old were almost confined to printing in silver, and lacked such splendid processes of reproduction as present workers may revel in, first and foremost among which I place the platinotype. Having said thus much to express my admiration for the process, I will give a few details as to the working of the paper, &c. Firstly, the paper must be kept perfectly dry before, during, and after printing. Secondly, the negatives should be, in my opinion, fairly dense, but soft, with details to suit the subject, and free from stain, especially yellow, to which colour the paper is but slightly sensitive, in consequence of which the development may be carried on by gaslight, and so simple and cleanly is the process that you may with the cold bath perform the necessary opera- tions in your own dining-rooms (if you can get the requisite permission) without the slightest detriment to the furniture. Thirdly, in printing it is necessary to back the paper with a thin sheet of vulcanised India rubber and by all means varnish the negative. Print till a faint grey image appears as if imbedded in the lemon-coloured sheet with a thin veil or film over it — a softness characteristic of the process without hard or decided lines obtruding themselves. In working the process it is not necessary to tie yourself down by inexorable rules (except with regard to the exclusion of damp) but every worker with intelligence may vary the composition of the bath or the extent of the printing to obtain different effects of tone ranging from silver grey to exquisite black full of trans- parency. I would advise beginners to print till the shadows and half- tones are faintly discernible, and to have two developing baths, one much diluted and the other of normal strength. Draw the face of the print over the surface of your first very dilute bath, and if the effect desired is obtained plunge the print into the acid bath to prevent further action ; but, it through insufficient printing or weakening of No. 1 the desired end is not obtained, then resort to the stronger bath and complete develop- ment on that. J. V. Brewer. AKT IN PHOTOGEAPHY : AN INTERVIEW WITH ME. FEEDERICK HOLLYEE. [Die Stuiio.~\ A COMMONPLACE-LOOKING room On the ground floor of a commonplace house in a quiet Kensington square, the demure plainness of its furniture relieved only by the soft grey tones of the countless platinotype repro- ductions of the pictures of that apostle of romanticism, Mr. Burne- Jones, which lined the walls. This is where I found Mr. Frederick HoUyer, a sturdy, broad-shouldered, good-humoured, and good-looking man of middle age, who comes nearer to the definition of artist-photographer than any other man in England. To the art-loving public in general, and to the section of the American community which deserves that title in especial, Mr. HoUyer is chiefly known and appreciated as the trans- lator into a more popvilar medium of the poetic fancies of Eossetti and Burne-Jones. To a smaller circle, however, that appreciation is widened into recognition of what may be called, without prejudice, his creative work, as distinct from his reproductive work with the camera. It seemed to me, therefore, eminently fitting that I should come to this modest oracle for a word on the vexed question of art and photography, .is luck would have it, I had made my pilgrimage at an opportune moment, for, taking advantage of the leisure afforded him by a rare holiday, Mr. HoUyer had, the day before, acquitted himself of a piece of work August 26, 1803] THE BRITISH JOURNAL OF PHOTOGRAPHY. 646 ■which I think represents the high-water mark of photographic portraiture. He had deliberately aet himself a task, the techi\ical and artistic diffi- culties of which would, to the ordinary man, hava seemed insuperable. The result, in the shape of a platinum print from the untouched negative, ^as hanging in his studio to dry, and I was gratified with the first outsider's glance at it. It was simplicity itself ; a charmingly pretty girl, dressed in a simple summer costume of pure white, standing at an open door, with her lingers resting on the handle as though she were on the point of going out into the little suburban garden, a glimpse of which was caught beyond. The upper part of the figure was seen against a background of absolute sunlight, and yet face, arms, white dress, hair, and dazzling sunlight were all given with a fidelity to values which would not have been unbecoming to a Whistler. In face of this result it seemed to me almost impertinent to ask Mr. Hollyer whether, in his opinion, there could be such a thing as " Art " in photography, for was there not lying before me, as I hesitatingly put my query, a clear answer in the allirmative ? He met me, however, with no expression of lofty scorn, but with a somewhat quizzical smile, replied, " I really don't know ; but, to tell the honest truth, I have got rather tired of the very -words ' art and artistic,' and at times am inclined to say rude things about those who insist so strenuously that they are artists, with a big .\, and seem to forget that they ought first and foremost to be photographers. The fact is that my association with the eminent artists whose works I have been permitted to render into black and white by means of my camera has rendered me exceedingly diffident in making any claims at all. I am content to do the very best work I can with love as well as care, and to let the rest shift for itself. If .there be art in the result, I am quite sure that those who have a right to be dogmatic on such questions will find it out ; if there be no art, I am sure it is my fault and not the fault of my medium. I think that the fact is that, as regards photography as well as other things, we are inclined nowadays to talk too much and do too little." "Very truly and modestly put, Mr. Hollyer," said I, "but I am afraid you have something more than an inclination to evade the real point at issue." " Well," was the reply, " to speak frankly, I am quite convinced that something, call it art or what you will, but something apart from mere mechanical and scientific excellence, not only can, but should, find its way into every print from every negative that leaves the photographer's studio. In landscape photography, for instance, that something may be of the nature of selection, and selection is, as I understand it, an important part of the equipment of every painter. Observation, too, I think, must be fostered by the photographer as carefully as by the figure- painter, for, if his work show not the presence of this quality in itself, it will be a mere piece of mechanism. I have some prints here from negatives taken by me many years ago to which I may, I hope, without egotism, refer as showing the importance of proper selection. This view of Waterloo Bridge, for instance, might have been taken from half a hundred other points of view, and yet from a topogi'aphical and mechanical standpoint have been as correct as I here show it. To make it pleasing to my own eye, however, I found there was only one spot from which I could properly view it. Having found this spot, 1 had again to patiently wait until the cloud and mist efifects, with the London sun just peeping through the murky veil, were as I thought they should be. Not only this, but selection came into play to tell me when the black barge was in the right relative position to the rest of the picture, and when other boats and floating objects, which might have formed discordant notes, were well out of the way. The result, whether good or bad, is practically what I had intended it to be from the very first, and is DO hap-hazard accident, but the expression of a deliberate intention, gained by careful selection on my part. At that point, of course, I stop, and the rest of the work is done for me by the camera, but I might almost as well declare that the etcher was a mere mechanical workman because the biting of his line is done by the acid and not by himself, as hold that because some portion, granted even that it be the major portion, of my work is done by an agent which I only imperfectly control, I cannot introduce into my work that personal note which I take it is but a synonym for the ' Art ' of which you speak. Of course I am aware that at one moment, and that perhaps the supreme moment, the actual recording of the observed facts is taken out of the photographer's hands. " This is the moment of exposure. Consider, on the other hand though, at how many other points the personal equation enters into our problem. First, there is the focussing (and though some writers on photography have disagreed with nie here, I maintain that I am abso- lutely correct in saying so) ; then there is the development ; thirdly, there is the manipulation of the print from the developed negative. Don't for one moment understand me to mean that that fatal crime of touching and retouching negative or print is or has been laid to my charge. On the contrary, no one can have a greater abhorrence of such acts than I. I consider it almost as criminal to form a picture by the superposition of one negative upon another. I am convinced that two photographers, equally skilled in the mere mechanical processes of their profession, can photograph the same object from the same point of view with the same camera, and under exactly similar conditions, and that the finished print of one man may be a mere soulless transcript of what lay ill his field of view, while that of the other may be something to which, for want of a better word, I must apply the term ' artistic' How much or how little of art may belong to photography is another qaeition, and one which I must refrain from entering upon. When, not ao very muiv years ago, photography came into being, the marvelloai re*alt« wbieb were produced by the very earliest photographers cansed an exaggerated opinion to prevail as to its purely artistic future. When, later on, its well-defined limitations became apparent, there was the asual reaction in the other direction, and those who claimed that art might in any form enter into photographer's work were sneered at as presumptuous Philistines. Surely there is safety in the middle course. If yon do not deny artistic faculty to the man who reproduces in black and white a picture by means of his patient ' rockings ' and ' scrapings ' of a copper plate, relying in a large measure upon reproductive processes which are entirely me- chanical, why should you not, then, attribute some degree of artistic personality to him who reaches the same end partially by means of the camera? Compare the work of different men in my own branch, and tell me whether there is not the greatest difference in the result, as regards not only the technical excellence but the artistic value of the translation as well. " Perhaps I have talked too much, for I hold, as I said when I began, 'that my mission is to do and not to talk. But I am as irritated, on the one hand, when I hear the flat-footed declaration that photography cac never be more than a mere mechanical trade as I ara restive on the other when I hear a photographer aver that, by combining a set of views taken at various times and hours of the day, he has effected what he fondly calls ' a picture,' as distinct from a ' mere photograph.' In other arts, and especially the subsidiary, it is their very limitations which the craftsmen turn with instinctive recognition to their own advantage. If this principle were only to be recognised and honestly lived up to by photographers in general, we should have results which would be better art, because t'aey would be better photographs." Hobace Townsend. THE PHOTOGRAPHIC CONGRESS AUXILIARY OF THE WORLD'S COLUMBIAN EXPOSITION. Sev'beal papers have been contributed to this Congress, which was held on August 1, under the presidency of Mr. James B. Bradwell, Chairman of the Uommlttee. We print the following at present : — WINTER PHOTOGRAPHY IN THE ALPS. Although it is now twenty years or more since winter visitors first came to the Alps, few photographs have been preserved which render faithfully an Alpine valley in winter. The subjects ready to hand are varied and beautiful, yet somehow one seldom sees first-rate photographs of these high-lying districts under snow. Those who have so kindly asked me to prepare this paper have greatly over-estimated my capacity for telling you some new thing. Still, bear- ing in mind the fact just referred to, it is evident that few persons have made a study of landscape photography at that season in the Alps, and thus, perhaps, the experience of one who has worked in that direction may be of some interest. Those taking up this branch of their art are usually handicapped at the start by their belief in an article of faith — and of little else — laid down by the majority of English photographers, who declare that snow should never be photographed m a bright light. I dare say that in your sunnier climate, which must offer many more opportunities for experi- menting in winter photography than does that of Great Britain, you have already discovered that brilliant sunshine is essential to the best results. But, in case any among you still hold to the unsound maxim, I would ask him to bear in mind exactly what snow is ; that it is nnform in colour, almost smooth of surface, and on dull days without distinct out- line against a grey sky. It must, therefore, be built up, so to speak, and modelled into that miracle of fairy delicacy and lightness Which, under favourable conditions, it may become. We can have it at its best by working with suitable light at suitable hours, and now and then calling to our aid one or two artificial but inoffensive contrivances. At midday in winter the light falls too directly on the subject ; the lace-like tracery with its system of irmumcrable tiny snow crystals, obtains no relief against the wlute robe, standing hard and stiff around rook and chdUt. But go early in the morning or late in the afternoon, and note the change. You will find in the long, soft shadows a thousand exquisite half-tones. See how the highest and nearer lights are broken, and broken again, by the thin veil of surface crystals, each with its perfect modelling, its tmy shade throwing up its star-like form. Look at the rounded billowy flow of the snow where, half in sunshine, half in shadow, it sweeps around and over the inequalities of the ground. If there has been a mist, however slight, during the night, a fretwork of hoar-froet will cover all, and will complete the materials tor as flue a subject m you can wish for. 546 THE BKITISH JOURNAL OF PHOTOGRAPHY. [Au^st 25, 189» Tou may find it desirable to use, in addition, the artificial contrivance to which I referred, and by Bhovelling some of the snow, or trampling out a track, break up any portion of the picture where the uniformity is too great. And now, having placed your subject under the most favourable con- ditions, what is the best way of photographing it ? My own experience leads me to think that slow plates are far the best, so that when used with a small stop the exposure can be as prolonged as possible. I have always used Wratton & Wainwright's " ordinary " plates for this purpose, with one of Boss's portable symmetrical lenses, and with the smallest stop. I give under the conditions of light just described an exposure of two seconds. In developing, I am careful to work up the plate very slowly and to carry the development very far, and when I have finished I expect to find a range of density from excessive blackness to clear glass ; but, though there must be no mistake about the quality of these two extremes, there must be very little of either. It is on the variety of the half-tones that the success of the picture depends, and it is for this reason that, in photographing snow, correctness of exposure is of such prior importance ; and therefore a slow plate, allowing of more laxity in exposure than a rapid one, is far easier to work with. A plate under or over-exposed can never, however skilful the development, give a perfect result if the picture is of a snow-covered landscape, as the half-tones must suffer from the error. I have used the iron developer, eikonogen, and pyro, and ammonia, and. for snow, have obtained the best results with the latter. I may add that, when developing photographs of large moving figures, taken in winter in the Engadine, on our skating rink, I get the most successful pictures by allowing the plate to flash up at once under eikonogen, and continuing the development until the principal object is hardly visible when viewed by transmitted light. For studies of this kind I have had the best results with Lamiere plates. Bnt I have digressed from my subject — because, probably, I had so very little to say. I have now all but done ; but, before concluding, I should like to draw your attention to the fact that very beautiful effects can be obtained in Alpine photography by facing the camera to the sun, which, of course, should be just out of the plate. For most subjects (water and clouds excepted) such lighting is rarely suitable — at any rate, in so extreme a form ; but with snow I have obtained most charming studies in this manner. In response to so great a compliment as has been paid me in requesting me to write this paper, it would have been ungracious on ray part to have refused ; but I must ask you to forgive the very inadequate manner in which I have responded, for I know but little of the technical side of photography, and of the practical side am but self-taught, by my love of an art the beauty of which has always warmly attracted me. Elizabeth Main. PRESENT AND FUTURE POSSIBILITIES OF PHOTOGRAPHY. To render an account of the present state of photography presents no diflSculties whatever, the facts to its credit being recorded everywhere, so that we need only draw from recent sources, the very ancient facts being, BO to speak, contemporaneous, in order to trace a complete history of photography up to the present hour, passing in review all its methods, all its countless applications. And, while we are desirous of justifying the very title of this paper, the circumstances aUow to foot on the past, admitting it to be well known to all of us, in order to arrive at a conclusion as to future possibilities which we are able to foresee, combining the progress of photography itself with the science of to-day. We are witnesses of a scientific progress so continuous and wonderful that it would be rash indeed, even if aided by the most exalted imagina- tion, to indicate the more and more extraordinary facts reserved to us even by the nearest future. New discoveries in the domain of general science will, without fail, result in unexpected photographic inventions, or in applications of photography to uses of which at the present time not the slightest idea can be formed. This is why we cannot approach the difficult subject which has been referred to us without a strong senti- ment of our complete inability ; in other words, this is a new world, inaccessible, which we set out to explore ; we would have to give proof of the fervour of our imagination, of a kind of foresight, more than of true science. We would be well inspired if we could embark on a journey to the beautiful land of dreams to talk with the fairest fairies, and would return to describe our visions and to explain the most fantastic and most wonderful facts, while now we are obliged to appeal to reason— to the reason of today — it may be well understood, for our reason changes its basis at every moment according to the conclusions it has to draw from evidences and facts which yesterday it denied and thought wholly impossible. But enough of philosophical contemplations, to which, however, we- were prompted by a prudence which every one will appreciate. Being thus under the protection of the unforeseen, we may now venture suppositions as fantastic as possible, and become prophets- without much merit of our own, since the past serves as guide in discovering future possibilities, which, hypothetical as they are, may b& admissible, because it has been shown that we need not doubt anything; in the course of scientific facts. The past belongs nearly exclusively to monochromy, designating thus any method which, by the aid of light, produces an image with more than oue colour, whatever colour this may be, and even images of more than one colour, obtained by the aid of monochromy, each having its own colour. The progress in this line has been very remarkable, especially since' the production of single images took the place of a multiplicity of copies. First, the paper prints obtained by a chemical process from one and the same plate ; then the commercial prints, obtained in a mechanical way with plates prepared with the aid of light, have made photography one of the most ingenious and faithful auxiliaries of the art of illus- trating all kinds of publications ; in one word, the automatical means of copying the most wonderful and most instructive objects which have ever been imagined. On the other hand, the considerable increase of sensi tiveness of the products exposed in the camera to the action of light, together with the invention of the dry film and the consequent porta bility and easy management, have caused an immense expansion of this art, which now in every respect is in the reach of all. Science has, not less than arts profited by the progress of photo- graphy, which made it an indispensable aid for its most delicate researches. To prove this we only need observe the excellent and I unsurpassed services rendered by it to astronomy, to physics, to the I study of the infinitely small, to the rapid and complete registration of I all phenomena of light and motion, even of the wonderful rapidity of the I minutest organisms. Indeed, it is at the same time an eye and a j draughtsman. Ijike the eye, it is gifted with the highest rapidity of vision, so much so that it sees objects as if they were stationary though they are alive with miraculous swiftness. Ah, it even sees what is invisible to tho human eye ! The stars bear witness — which, though unknown till now, have been discovered by the photogrophic eye in the depths of spade, : inaccessible to our most powerful telescapes. The reproduction of ultra- violet rays bears witness — which, for our power of vision, belong to the invisible. ' As a draughtsman it is unrivalled, for nothing equals the definition of the I lines it traces, ihe accuracy of the endless details it reproduces, the truth of which is such that it has the force of the evidence of a witness. We may add that it is also an artist. Indeed, thanks to entirely successful researches, we are able to obtain impressions on the sensitive medium I by the aid of light of all colours, in proportion to the degree of luminosity of the different colours. This progress was achieved but slowly, and, now that it has become an accomplished tact and practically within I the reach of all, it gains ground slowly ; but this can be only a question of time. Since we are able to sensitise our products so as to render them susceptible to impressions of all colours, giving them a perfect ortho- chromatism, it must also be possible to render them more sensitive to one colour than to another. I This possibility of selection must lead to the production of mono- chromes corresponding to every one of the principal colours, and conse- quently to the representation of the colour effect of an object or of nature, by superposition of the different monochromes, each having its own colour. Therefore, photography, being the most skilful draughtsman and litho- grapher, and the most admirable engraver, is also a wonderful expert of colour. But it is even more than this, it is already the artist of entire pieces of art, producing by one single action the colours of objects, much as it impresses the sensitive monochromatic plate. And, what a really wonderful idea, we begin to trace on the sensitive film the true image thrown into the camera, with its reality of detail and of colours. And this is our present position. The development during more than fifty years has been nearly com- pleted, because we have succeeded in passing through all possible phases of the art of designing and of its applications, attaining even to the art of painting. Wc say -'attain," by which is not meant that we have advanced in the subject of colour photography to a point which we did not gain in monochromatic reproductions. August 25, 1893] THE BRITISH JOi;RNA.L OF PHOTOORAPnY. W7 The most characteristic name which might be given to the preseut «poch is that of a new era. We are on the threshold of the art of polychromy. Indeed, in scientific applications, the first step counts most, as perhaps it does in every other field. Wa have only to direct our attention to what is going on in the electric world, and then to proceed by analogy. There we have arrived at a point at which even ihe most fertile imagination could not pass beyond the scientific wonders of the future, even if its flight would lead us into the most fantastic dreams. No doubt electricity, with its power, its invisibility, its enormous rapidity of propagation, will become an ally of photography to aid in the •creation of unexpected wonders. Already they speak of plates exposed and developed by the aid of an electric current. Kdison is at work to construct an instrument intermediate between the phonograph and his kinetograph, which will enable us simultaneously to see the motions of a person, to hear his voice, his words, put in immediate harmony with his gesture, his attitude, the play of his lips and eyes, &c. This has not only been taken into consideration, but can be realised — " probably it is realised— at this hour. But this is not all. By electricity eimilar effects may be and are (why not speak aflirmatively, since such is our opinion ?) transmitted over a distance. Thus, using the electric telegraph at the same time as telephone and as kinetograph, we will be able to communicate the oomplato effect of form, (notion, and sound to points far distant from the scene of action. So far we have spoken of the form, which involves the idea of outline and detail of objects. Will a transmission of colours become possible ? Will we be able to complete the characteristics of an object by com- municating through the electric wire not only its outline, but also its colours ? Why should we not admit this possibility, extraordinary as it may seem? How to get there? Tliis is the point which m oae yet knows; but, considering the present state of our scientific resources, based on the divisibility of matter, it does not seem impossible that wo may arrive at results of this kind. Passing in review the history of development of electricity, are we not convinced that about fifty years ago no one would hive believed a prophet of the future foretelhng all the present wonders of the spark ? We do not burn the wizard any more, at least in civilised countries, but they are still treated as fools. Well, we cm no longer denounce folly in view of scientific predictions of the most revolutionary character. AU we are allowed to say is this : "Who can tell! This maybe rery well possible." Thus we do not risk to engage in a dispute which sooner or later will be decided against us by the facts. Speaking of the progress of photography which may be realised, we think at once of a higher sensitiveness, which would allow of instantaneous impressions even with the feeble light of interiors. The sensitive pro- duct, or at least its vehicle, shall have the fineness of the collodion or albumen film. The apparatus, perfect as it is, still shows an incessant tendency to improvement. From the standpoint of expanding the field of photography until it reaches every home, the ideal will always be an apparatus essentially portable, of small weight and volume, permitting us to photograph with- oiA being observed, and containing a number of plates or flexible films, sufficient for a large number of successive exposures. The favourite of the future is evidently the flexible film or the very small plate, so that, after a sufiicient perfection of the rolling apparatus, an endless ribbon may be advantageously substituted for a certain number of single plates. The rolling device lends itself better to a rapid succession of new sen- sitive surfaces, but its operation must be made more reliable and easier. This evidently is a field for the future. The future will find enough work in the development of photography, and persons who believe that very little is left to extend its field are badly mistaken. Well, what is it ? they ask. There is the question of colours, and, saving some perfection in details, that is all, isn't it ? First, in regard to colours, it is by no means a small step forward to bring this branch of reproduction to that degree of perfection which we have attained in monochromes. If such a great step has been taken, inducing us to believe in a possibihty of reproducing colours, and proving that the means of direct reproduction of colours exist, it is not less true that all is done with a view of applying it to industrial uses, either to obtain simply and easily direct prototypes from nature, or to multiply poly- chromes with the aid of these prototypes. The very day this possibility is recognised and justified by facts, nobody will do anything but take polychromes. But the perfect realisation of this hope will not come withoat exteniive further researchei. It will be necessary tr> conquer step by step, with the aid of successive progress, and no one is able to foresee how many yetri it will take us to arrive at the perfection of this process. Occupied with this most attractive study, we may ask, what other applications remain to solicit our earnest endeavours? Is it not surprising that so little has been done until now toward employing photography in industrial decoration of ceramic and tissue ? And, besides, we have everything necessary to pursue this line with success. To the future, therefore, is left an application as important as useful, and we hope that this work will be accomplished in an excellent manner. How long before the constables, policemen, and detectives will be provided with detective cameras, permitting them to add to their words as witnesses the proof of the crime and of the identity of the criminals ? Though we have now all that is necessary for this application of photo- graphy, so simple and useful, yet it remains still to be realised. How long before we think of introducing into our schools and colleges the study of photography practical enough to enable each scholar of either sex to constantly use the pencil of photography, according to the lessons of the course pursued, for gathering all the souvenirs on their excursions and voyages ? If this could be done, the application of the photographic lens to cer- tain functions would cease to present difficulties. We have already sounded far, very far, into the depths of infinite celestial space by photographic investigations, but they are less applied to terrestrial or submarine uses. Geology would find it advantageous to verify the symptoms of life in the depth of the abyss, aided by a photo- graphic apparatus, combined with a magnesium flashlight, which may be lighted at a distance by electricity. The same might be done below the surface of the water, in depths which no ere has yet beheld, and thus an investigation of submarine landscapes, so to speak, would prove to be of priceless value to science. We have not yet encountered any impossibility, and the well-known facts suffice to give immediate results of the highest value. How much remains to be done in regard to the methods and nature of registration ? We cannot form an idea thereof. Why, for instance, is not the portrait obligatory on the passport ? What better proof that this is Mr. X. who speaks to you than the presentation of his duly executed passport bearing his picture ? On the train, at the hotel, at the public places visited by travellers, at the windows of the telegraph and post-offices, and of the banks, &c., every one appearing should leave, without his knowledge, the proof of his presence, in the shape of an automatic, direct, and permanent reproduction. What an aid would this be for the researches of the department of police, for the proof of alibis, .'"-"-i::"_U'U'-'. 64» In oondasioD, the point! to which I wish to draw attention are :^ 1. In every county it is desirable that a photographic survey should be initiated. By the term " survey " I here mean a pictorial record of the state of things, physical and Roneral, as now existing. 3. In each country there should be {a) local dopi^ts containing complete seta of permanent photot^raphic prints of the district ; and (b) a central bureau containing negatives and prints. 3. Facilities for the exchange (or purchase) of prints, &o., should be provided. It has been well said that " all photographers are brothers," for it is certain that the study of this light science, though black art, tends to bring its fellow-workers together in no ordinary degree. Moreover, photo- graphy is more and more employed every day as a means of record in every branch of science and of art. It is of the utmost importance then, that the students of this subject, both in England and in the United States, should become acquainted with each other's work, and should be able to avail themselves of it. If this principle be once recognised and approved of, then the details by which it can best be carried out might safely be left to a committee appointed by the conference, should they see lit to do so. W. Jkuome Harhison, F.G.S. ©ur iEtiitorial CTatle. Thb Watkins' " Joniob" Exposubs Mbteb. A NEW and simple form of the Watkins' Exposure Meter has been issued under the above name by Messrs. K. Field & Co., 142, Suffolk- street, Birminp^ham. In this, when the adjustments are once made for plate and diaphragm, the different exposures due to variations of light during the day can be read off without further adjustment of the in strument. By comparing the cut with that which has previously appeared in connexion with descriptions of the Wat- kins' Meter, it will be seen how much it has been simplified. This will con- duce to further popularising an instru- ment which is one of great reliability. An improvement in the "Junior" consists in transmitting the light to the sensitive paper through an end piece of blue glass. The price of the "Junior " is 7 s. 6d. NoETHERN Photographic and Sciksmfic AssociATioif.— August 26, Hatfield. Hackney Photoqraphic Society. — August 26, Excursion to St Margaret's. Take excursion ticket for Rye House. Leave Liverpool-street by quarter past two train. Tea at Pied Bull, Stanstead. 29, Daylight Enlarging. Lbytonstoxe Camera Club. — August 26, Buckhurst Hill. Leader, Mr. A. Frost. The Club will proceed by the train leaving Liverpool-street, Great Eastern Railway, at thirty-five minutes past two p.m., calling at Leytonstone at tight minutes to three, arriving at Buckhurst Hill at seven minutes past three. Open Social Evening at Headquarters, eight o'clock. Midland Camera Club.— The First .\nnnal Exhibition of the Club will be held at the Botanical G.ir.lens and College Grounds, Moseley, Birmingham, to open on Monday, October 2, and close on Saturday, October 14, 1893. Parti- culars and forms may be obtained on application to the Secretary, Mr. C. Jevons Fowler, 4, WooJstock-road, Moscly, Birmingham. Accident to Mr. Bibt Acres.— We are sorry to learn that an accident of a serious nature has happened to Mr. Birt Acres. He was experi- menting with sodium for tha pro luction of hydrogen for a particular purpose, and was making use of about sixty grains of it wrapped in fine gauze to prevent the gas from becoming ignited. But as soon as the sodium touched the water a terrific explosion ensued which tore a large hole in a thin sheet iron drum he had in his hands ; he was also holding the sodium with a pair of ordinary pliers. How he escaped without still more serious injury than he has sustained is a mystery, but it is probable that the water having been dashed in his face by the force of the explosion saved him. From Tuesday (last week) until Saturday he was totally blind, but on the latter day he recovered the use of one eye, and the doctor holds out the hope of a similar recovery of that of the other one shortly. We know that sodium ignites when it is brought into contact with water, but were not aware that such ignition was accompanied by an explosion, and we shall await with much interest such details as, on his recovery, Mr. Acres may be enabled to give as. Meantime we accord him our sympathy, and rejoice that the consequences, serious though they be, are not still worse. RECENT PATENTS. APPLICA-nONS rOR PATBNT8. No. 15,383. — "An Improvea{ei/ Avffust 15, 1893. No. 15,621.— "An Improvement in Photography." C. F. Cboss and W. Nklsou.— Cai. No. 12,655.— " Trimming Photographs." RffrriE. improvbmkhts w photographic apparatus on thb plnholk alb lcks Principle. No. 13,632. Archibald Campbell Ponton, Viewfield, Parlutone, Dorset- shire.—^ii/y 26, 1893. The invention relates mainly to the construction of cameras for taking pictures rapidly through very small pinhole lenses, the focal lengths of the air lens or, what is the same, the depth of the camera being apportioned to the rapidity of exposure. I find that I may use pinholes as small even as jjj, of an inch in diameter. These may be formed m metal foil, snch, for instance, as ot pKitinum or brass, and are inserted in the lid of a box-shaped camera. The latter may l>e made of cardboard or sheet metal, and may be pressed up. The interior size of the camera should be that of sensitised plate to be used, and of the depth of the focus of the air lens. I prefer to make the camera in two parts, one fitting into the other like the ordinary cardboard box in which sensitised plates aie sold. The box lid may, by partition or partitions, be divided into two or four coiupartnients for the production of ssveral photo- graphs on one sensitised plate, thus, for instj>nce, adapting it for stereoscopic pictures. On the outside or inside of the lid I provide a movable lever-shaped or other shutter, which, for two pinholes for stereos may be T shapetl and working on a pivot. This apparatus may be made so light as to only flightly exceed the weight of the plates themselves, at the same time it can also be made at a very low price indeed, so as to bring it within the reach of the million. From the small negatives produced by this apparatus the positives can be printed in an enlarging camera of the size most suited for trade purposes. Negatives taken with an air lens of yjVii "f »■» i°<^b in diameter for stereo- scopic pictures are found to give a suffieient field to be printed from direct by contact. Improvements is and belatisq to Photographic Cavbras. No. 14,753. Walter Grifkiths, Highgate-square, Birmingham, Warwickshire.— ./ii/ySS, 1893. My invention has for its object improvements in and relating to photo^phic cameras, by which I obtain a much more durable article, which is particularly suitable for export by reason of its freedom from liability to be affected by the intense heat or cold of other climates, while it is much stronger in construc- tion, without losing the delicacy of movement and adjustment of the variona parts, which is so essential to a first-class camera. At the same time it is simple in construction, and my improvements are embodied without in any wav increa-iing the cost of the camera. By my improvements in relation to the dark slides for use in cameras, I also obtain a mnch more durable article, which, at the same time, is more compact, and also does not increase the cost of manufacture, such dark slides being cheaper than the ordinary ones of equal quality. In carrying my invention into effect, I form the bottom, or under ftume, of my camera of metal tubes, with, say, two longitudinal tubes, and two cross tubes attached, as to form a square base, and with the longitudinal tubes mounted upon the cross tubes within each longitudinal tube, « second tube is telescoped, and upon the front ends of these two inner tubes another cross tube is mounted, to the centre of which one end of another longitudinal tube is attached; this latter longitudinal tube passes through a socket formette)S* MEETINGS OF SOCIETIES FOR NEXT WEEK. Date of UeetiDg. Name ol Society. Place of Meeting. Aagost 28 Dundee Amateur . „ 28 j North Middlesei . ■I 28 ' Richmond . M 29 Birmingham Photo. Society „ 29 Hackney „ 29 i Halifax Camera Club.. >, 29 ' Lancaster >. 29 Leith .. 29 ! Paisley >f 29 Rochester t* 29 i Warrington „ 3» ' Bath >« 30 , Burnley ■V 30 1 Leytonstone •t 30 Photographic Club » 30 1 Sonthport •■ 31 ^ Glossop Dale If 31 1 Halifax Photo. Club .. 31 Htdl f* 31 Liverpool Amateur *f 31 1 London and Provincial .. >, 31 ! Oldham September 1 Cardiff.. 1 Croydon Microscopical 1 Holborn 1 Leamington 1 1 Maidstone 2 ; HaU Aflso. Studio, Nethergate, Dundee Jubilee House, Hornsey-road, N, Greyhound Hotel. Club Room, Colounade Hotel. 206, Mare-street, Hackney. Springfield Barracks, Lancaster. 165, Constitution-street, Leith. 9, Gauze-street, Paisley. Mathematical School, Rochester. Museum, Bold-street, Warrington. Roy. Lit. i Sc. Inst., Terrace-walks. Bank Chambers, Hargreaves-atreet. The Assembly Rooms, High-road. Anderton's Hotel, Fleet-street.K.C. The Studio, 15, Cambridge-arcade, Mechanics' Hall, Halifax. 71. Prospect-street. Hall. Percy-buildings, EberJe-street, Champion Hotel, 15. Aldersgate-st. The Lyceum. Union-st., Oldham. Public Hall, George-street, Croydon Trinity Church Room, Morton-st. " The Palace." Maidstone. 71 Prospect-street, Hall. PHOTOGRAPHIC SOCIETY OF GREAT BRITAIN. At a meeting held on Tuesday last, the 22nd inst. , Mr. G. Scamell occupied the chair. Mr. T. BoLAS, in giving a demonstration of Flashlight with the metal Alu- minium as a ComhvMilile, mentioned that an assertion had been made that aluminium could not be usefully burned in such a Hash lamp as is used for magnesium, but this statement had arisen out of the somewTiat dangerous practice of positively asserting a negative proposition, merely because the speaker had not seen the positive side demonstrated. It wa.s then pointed out that a very fine state of division i< essential in the case of a flashlight witii aluminium powder, as otherwi.se the metal passes through the flame without being: heated to the somewhat higli ignition point of the metal. When the aluminium does burn, it produces a more intensely actinic light than magne- sium, as the temperature of combustion is higher. The commercial aluminium bronze powder, as manufactured at Fitrth and Niirnberg, but sold in London by Mr. W. C. Home, of White Horse-alley, Cowcross-street, was then shown in three degrees of fineness, costing about seven- teen shillings per pound, and was recommended, the minute scales composing this being abont one-five-thousaudth of an inch thick. This powder, as sold, is covered with a very minute trace of the oily matter used in its manufacture and this causes it to hold together in clots when blown through a flame, and so, as was demonstrated, if used .just as sold the greater part escapes ignition. In order to fit it for use in such an ordinary flash lamp as that of Mr. England, this oilv matter must be removed, and Mr. Bolas showed how this may be done. The powder was merely heated to about the temperature of melting zinc, in a test tube, and after this treatment it had no tendency to clot, and it is blown about, with eacli grain separate, by the slightest breath. About a grain and a half of the powder was now burned in an England's flash lamp, and by the light Mr. W. E. Debenham took a fully exposed portrait of the Chairman. Other ways of using aluminium (leaf in oxygen, and the powder mixed with potassium chlorate) were now shown, but Mr. Bolas said the object of his demonstration was principally to show tliat aluminium can be used in the flash lamp, and that it can be much more completely burned than is usually the case with magnesium powder. *If magnesium is so finely powdered as to burn completely, it oxidises or rusts very ciuickly, and so becomes useless. Tlie aluminium dust may be kept without tear of deterioration by slow oxidation or rusting. Mr. Andrew Pringle and Mr. Clifton both spoke of the inconvenience of the magnesia smoke, which is peculiarly irritating to their lungs, and they remarked that the alumina smoke did not appear to have irritating qualities to the same extent. Mr. Bolas said this was easy to understand, as magnesia is a caustic earth almost as irritating as lime, while alumina is bland or neutral. Mr. Pringle now made a com:r.uuication on photo-micrography with lenses not specially corrected for photographic work, and his results fully confirmed Dr. Pifi'ard's observations that such lenses will work to focus if a yellow screen and orthochromatic plate is used. Such microscopic lenses as those of Powell, a Lealand, or a Ross will give excellent and sharp results if the screen and the orthochromatic plate are used. LONDON AND PROVINCIAL PHOTOGRAPHIC ASSOCIATION. The usual weekly meeting was held on August 17, Mr. R, Beckett in the chair. Notice of a special general meetiug was read; the object of which was to dis- cuss a recent alteration of rule 7, respecting the election of members. August 31, was fixed as a suitable evening for the purpose. Mr. P. EvEBiTT showed a lens mount made by Mr. Haddon, and remarked upon its being a good piece of amateur workmanship. The Chairman passed round a negative having markings upon it. A general opinion was formed that they had been caused by mechanical abrasion whilst moist. Mr. Fry had had similar experiences during hot weather, the defects appearing after development, and iluring the period of drying ; he considered them as being caused by decomposition of the gelatine in the presence of heat and moisture. Some results of the recent meeting at the "Zoo" were shown by Messrs. Boyston and Steinmetz, It was suggested that the members who were present on that occasion should show their jiictures at the meeting on August 31. Mr. Welford read his report upon the Convention meeting as a delegate of the Association [see page 543]. After reading the report, he handed round the small album which contained it, as well as prints from negatives taken on the occasion. After a few remarks from Mr. Fry, the other delegate, Mr. Haddon proposed a vote of thanks to the delegates, agreeing that the excursions were too numerous, and saying how much non-members of the Convention lost by holding aloof. Mr. EvERlTT supported the vote of thanks, and moved the adoption of the report. The Chairman and Mr. Debenham agreed that great benefit was derived from these meetings. The Hon. Secretary seconded the adoption of the report, which was then carried. Mr. Welford acknowledged the thanks. Mr. Debenham quoted a letter whicli appeared in the current number of a photographic paper, stating that some lenses would not work to focus with a yellow screen. He pointed out that this occurred through the operator focus- sing before introducing the screen, instead of with the screen in position, inasmuch as the screen has the eflect of lengthening the focus about a third of its own thickness. After a discus.sion involving a slight modification of the delegates' report, the meeting closed. • Hackney Photograplilo Society.— August 15, Mr. T. H. Smith in the chair. — Work of the members was shown. Mr. Vining asked what was the particularjadvantage with tabloids .' The Hon. Secbktar r said they saved measuring, and were convenient when away from home, but care must be used that they are thoroughly dissolved before use. Mr. Wire asked what caused yellow spots on amidol-developed bromide paper ? Mr. Welford thought August 25, 1893] THE BRITISH JOUKNAL OF PHOTOGUArHY. Kl amidol itself was not the cause. From the qne«tion-hnx : " Which is the belt illuminant for printing in clouds on lantern slides ?" Mr. BlcKETT said K«s was more regular. The Hon. SBcnBTABY agreed, and said gas was more under control, and printing-in al.-io. Mr. PaRRV said he had been troubled with yellow P.O.?. prints. Mr. Beckett said perhajia the lirst washing water did not carry off the silver, and doubtless the .sulphocyanide was impure. Mr. W. L. Barker had recently teste, Mr. W. H. Harrison, Some Useful Photographic Sta/ulards. ♦ FORTHCOMING EXHIBITIONS. 1893. September ^ *Royal Cornwall Polytechnic Society, Falmouth. W. Brooks, Laurel Villa, Wray-park, Ileigate. „ 20-21 'Hove Camera Club. Hon. Secretary, H. Emery, 142, Church-road, Hove, Brighton. ,, 25-Nov. 15... 'Photographic Society of Great Britain, 5a, Pall Mall East, S.W. Assistant Secretary, K. Child-Bayley, 50, Great Kussell-street, W.C. October 1-31 'Hamburg. Das Ausstellungs Committ^ des Amateur Photographen Verein, Schwanenwik, 33, Hamburg, „ 9-Nov. ... 'Photographic Salon, Dudley Gallery, Piccadilly, W. Hon. Secretary of Organizing Committee, A. Maskell, 215, Shaftesburj-.avenue, W.C. November 7-11 'South London P'hotographic Society. Hon. Secretary C. H. Oakden, 53, Melbourne-grove, Dulwich, S.E. ,, 20-25 'Leytonstone Camera Club. Hon. Secretary, A. E. Bailey, Rose Bank, South-west-road, Leytonstone. December 'Madras. The Hon. Secretary Amatejr Photographic Society, Madras. * Signifies that there are open classes. ♦ CorrejSponUtnce, ' Ccrrisponients should ntvtr irnfc on both siiet o] the poper. Xo notiM i» iaJwn of oommuiucattons unless the names ani addressed of the vriters are givtn» PHOTO-SIICROGBAPHY. To the Editor. Sir,— Mr. Smith calmly assumes that " cheap French triplets " can- not produce fairly good negatives of microscopic objects, his experience being that " it is impossible they can give a sharp picture of any- thing." As a simple test I have hunted up and have forwarded to you an old album containing upwards of two hundred prints, and would be obliged by your looking over it and giving your opinion as to whether I am or am not correct in stating that " I got fairly sharp definition up to, say, 400 diameters."— I am, yours, THE ■WORLD'S CONGRESS OF PHOTOGBAPHEBS. To the Editor. Sir, — the following report of the first business at the Thursday session of tbe World's Congress has not been reported in the general press, but I think it might be of interest to your readers. — I am. yours, &c., H. Snowdkn Ward. On Thursday, August 3, before the programme was commenced, Mr. H. Snowdcn Ward pointed out that a suggestion contained in Judge Bradwell's opening address had been overlooked by the Congress, and proposed that it should be acted upon. The suggestion was that Mr. W. Jerome Harrison's paper on The Desirabilitj/ of an JiUernational Bureau, estailished (1) to Jiecord ; (2) to Exchange Photographic Sfegutives and Prints, should be read in advance of its proposed order, and that a Committee should be appointed to carry out its suggestions. Mr. W. A. Ctooper seconded the proposition, which was carried. Mr. Harrison's paper recommended an international bureau connected with national bureaus for the collection, preservation, and exchange of photographs of historical, scientific, or literary interest. The meeting voted that the President should nominate a Committee to undertake what might be possible in furtherance of the scheme, and Judge Bradwell therefore nominated. ft Snpwden Ward (chairman), London. Gayton A. Douglass {vice-chairinan), Chicago. W. Jerome Harrison, Birmingham. John Carbutt, Philadelphia, Shapoor N. Bhedwar, Bombay. Leon Vidal, Paris. W. K. Burton, Tokio. Mrs. Elizabeth Flint Wade, Buffalo. Dr. John Nicol, Tioga Centre. CELLULOID FILMS. To the Editor Sib,— In reply to Mr. "W. J. Stillman's letter in your last number, wishing to know the experience of amateurs as to the deteriorating influ- ence of celluloid on the emulsion, I do not think that the celluloid has any deteriorating influence whatever on the emulsion, although ureat pressure might perhaps tend to cause some fog, but could easily be prevented by packing the films in a flat box. It has also been said that the image on films deteriorates after exposure if kept for some time. To test this, when in the Riviera last winter, I exposed two 10 x 8 films from the stone pier at Mentone for exactly the same time, no clouds, strong sun, 16-in. lens, /-IG, and Stanley's Shutter, one-tenth of second. One I developed a day or two after, the other was kept nearly two months. If any difference, there was a little more detail in the shidows of the latter, the same developer used for both, viz., pyro and ammonia. I exposed in the Memorial Church at Cannes a 10 x 8 instantaneous plate, and a 10 x 8 isochromatic medium film, both from the same maker, the rapidity of each supposed to be the same— the plate I developed with the hydroquinone developer, now so much used in France, and the film with pyro and ammonia. The plate yras much under- exposed, the window being very much blurred ; the film was a good negative, with scarcely a trace of blurring. Both were exposed twenty- three minutes. Films doubtless require more careful treatment than plates, but I tbmk they will soon replace glass to a very great extent.— I am, yours, Ac, F. Beaslbt. 552 THE BRITISH JOURNAL OF PHOTOGRAPHY. [August 25, 189.'i INVEKSION OF THE EETINAL IMAGE. To the Editor. SiB,^ — Many of your readers would, no doubt, be interested in Mr. W. I. Chadwick's paper on stereoscopy. As one who has taken an interest in the curious fact of an inverted image, a fact which most people are quite unconscious and ignorant of, I must say that I cannot consider Professor Pick's theory, as stated by Mr. Chadwick, to be the " most reasonable." To my mind, the difficulty is better explained by the " law of visible direction." We are all aware that we may roll about our eyes as we choose, and yet all the objects around us remain in the same directions, as they always appeared to us to be in. Now, no camera on earth would stand the same test, for, move about the lens, and a corresponding movement will take place on the ground glass ; in fact, the directions of all objects •will apparently be changed. From this it may be argued that there must be in the eye somewhere a fired point, and that through this point the rays of light forming the picture pass to the brain. As I said before, this seems to me a more reasonable theory than that which holds that the nerves of sight and feeling are co-operative. The amateur and professional photographer, no doubt, does become accustomed to the up-side-down image on the ground glass, but he never sees that inverted image erect, nor will his knowledge of its true position help him in the slightest degree. — I am, yours, &c., David K. Bose. Dalhousie-terrace, Edinbjirgh, August 19, 1893. iExctange (ttolumn. *,* No charge is made Jor inserting Exchanges of Apparatus in this column ; but none will be inserted unless the article wanted is definitely stated. Those who specify their requireinents as ' ' anything useful" will therefore understand the reason of their non-appearance. The full name of the advertiser must in all cases be given for publication, otherwise the Exchanges will not be inserted, "Will excbangre a 5x4 hand, or stand, camera complete for a light half -plate camera or lantern. — Address, H. Couch, 11, Waterloo-crescent, DoTer, Will exchange a Derogy's seven-inch focns cabinet portrait lens for a good cabinet rolling press.— Address, J. HOKlon, Central Photographic Studio, Caroline-street Cardiff. Itetonching desk for half-plates and under with mirror, &c., never been used, cost lOi. Will exchange for half and qn*rter-plate printing frames in good condition of same value.— Address, W. H. Browkk Deaki, i, Charles-street, Cambridge. "Wanted, modern half -plate camera, with three double backs, in exchange for 7x5 rapid rectilinear lens and quadrant camera carrier to fit on tricjcle, made specially to avoid vibration.— H. Masistbe, photographer, St. Mary-street, Chippenham ansstoetsJ to ©orresponticntg. *»* All matters intended for the text portion of this JonRNAL, including queries and Exchanges, must be addressed to " The Editor, The British JOURNAL OP Photoqraphy," 2, York-street, Covent Garden, London. In. attention to this ensures delay. *,* Correspondents are informed that we cannot undertake to answer com- munications through the post. %* Communications relating to Advertisements and general business affairs should be addressed to Messrs. Henry Greenwood & Co., 2 York-street Covent Garden, London. ' *,* It would be convenient if friends desiring advice respecting apparatus, failures in practice, or other information, would call at the Editorial Office either on Wednesdays from i to 6, or Thursdays from 9 to 12 noon, when some one of the Editorial staff will be present. Photogbapbs Registbred : — Alexander Campbell Hutchison, North Berwick.— Fiew of Bass Rock. Thomas Bramwell, Alston.- Two pJietographs of the 66th JPield Battery. Sydney Victor White, Reading.— Tien- of the foundatim of a Christian Chwch dii. covered at Silchester, Collodion.— We are in hopes of having a special article on the subject soon. Coi:cH.— The Convention group given in the Journal was not an enlarge- C. A. M. W. — Under the circumstances, we would certainly tilt the camera and use the swing back. Lens. — If you send the lens, we will tell you what we think of it. The other may or may not be good. Try it before you make the purchase. B. C. — The idea is not patentable. George Mason & Co., of Glasgow, manu- facture a similar adaptation to the camera stand to keep the legs rigid. F. E. G. — It is probable that the transparent spots in tlie negative arise from tiny bubbles ia the emulsion, and are not due to faulty manipulation on your part. B. T. (Yarmouth). — As the spots, identical in their character, occur on clif- ferent brands of plates, it is clear that they must be due to something in tlie development. BUBBLKs. — See "American Notes" in present number. Such pictures are not done by double printing. Let the child practice blowing bubbles for a little time previous to being taken. D. H. W. — There is ao false perspective in the picture ; it is violent, owing to its being taken with an extremely wide-angle lens ; but, if it be viewed from a distance equal to the focal length of the lens, even that will disappear. Zeno.— Without saying positively that the spots on the prints are caused by particles of bronze powder, we strongly suspect, from theu- appearance, they are. The name, So., are printed in bronze, not gold, and particles of bronze powder are plainly to be seen on the uncovered portions of the mount, T. NiCHOl.? writes : "Would some kind readers give me a formula for and directions for preparing a printing-out gelatine paper that will yield better colours than those now supplied, and which can be blotted ort' or mounted wet, like albumen'paper ?" — Perhaps some "kind reader" will oblige our correspondent. E. H. Thomas. — We can say nothing as to why the plates will not work in your hands, unless it may be want of experience. The peripatetic workers in the streets of London and its suburbs appear to get tolerably good results upon them. If the house named cannot supply the Phcenix plates, apply to Mr. J. J. Atkinson, Liverpool. T. NoRRis. — The titles of subjects can be conveniently put upon the negatives with the simple appliances advertised in our columns as the " Nameit." The titles on the subjects issued by the firm mentioned are written upon tlie negative with a sable brush and a black varnish. Of course, tlie latter system requires some skill to do it neatly. Country Town.— Your case is precisely similar to many others. The "big illustrated," as you term it, has pirated your Wews of the neighbourhood without let or licence ; but, as you failed to make them copyright, you have uo remedy. Common courtesy ought to have secured an acknowled»meut of the source from which the pictures were obtained. But that is not possessed by some of the illustrated periodicals. G. Simmonds. — As the condenser you require is only eight and a half inches in diameter, you will find it more economical to purchase it complete, or to get a pair of plano-convex lens&s and mount them yourself, than to attempt to build them up out of clock glasses — that is, if time is of any value. Although condensers that will answer well may be formed with suitably curved clock glasses, plate glass, and water, it requires some degree of skill to make them so that they will not leak after a short time. For so small a size as this, we should say it would be cheaper to buy lenses and avoid future trouble. In\'entob. — If, while you were an ordinary weekly servant, you invented a great and valuable process, which is now being worked as a secret one, and for which you received no remuneration, but, instead, were shortly after- wards discharged, we see no reason why you should not work it on your own account, or in connexion with any one else you may be associated with. We presume that there is no agreement that your invention is the property of your late employer. H. M. asks : " 1. Could you inform me if there is a protection gr.anted prior to taking out a patent for an invention ? 2. If so, what would be the cost, and where to apply for the same .' 4. Would the specification be sufficient to send?" — In reply: 1. A provisional protection can be obtained for nine months for a Government fee of 1/. 2. Make application, on the proper form, to the Comptroller of the Patent Office. The Office supplies the forms. Or the application can be made through a patent agent. 4. Yes ; the com- plete specification can be lodged and a patent secured for four years, the Government fee in this case is 4/. The third query has been omitted. OONTBMTS, COUNTERACTING THE HEAT IN THE studio AND OPERATING EOOM .... M7 PURE OXYGEN asu MIXED DEVELOPING FOBMUL/E 638 OPTICAL TRUTH AND VISUAL TRUTH. By H. DENNIS TAYLOR 540 AMERICAN NOTES AND NEWS 6*2 THE PHOTOGRAPHIC CONVENTION, 19»S. By WALTER D. WELFOBD 6« CAMERA SUPPORTS. By J. PIKE 5U PLATINOTYPK. By J. V. BREWER .... iU ABTIN PHOTOdRAPHY: AN INTERVIEW WITH MR. FREDERICK HOLLYEB. By HORACE TOWNSKND 6t4 THE PHOTOGRAPHIC CONGRESS AUX- ILIARY OF THE WORLD'S COLUMBIAN EXPOSITION. By ELIZABETH MAIN Hi Pase PRESENT AND FUTURE POSSIBILI- TIES UF PHOTOQRAPHY. By LEON VIDAL 5W THE DESIRABILITY OF AN INTER- NATIONAL BUREAU; ESTABLISHED (11 TO RECORD: (2l TO EXCHANGE PHOTOGRAPHIC NEGATIVES AND PRINTS. By W. JEROME HiVBRISON, F.O.S 6*< OUR EDITORIAL TABLE 64!) NEWS AND NOTES 649 RECENT PATENTS 64» MEETINGS OF SOCIETIES 666 FORTHCOMING EXHIBITIONS 651 CORRESPONDENCE 661 EXCHANGE COLUMN 668 ANSWERS TO CORRESPONDEMIg THE BRITISH JOURNAL OF PHOTOGRAPHY. No. 1739. Vol. XL.— SEPTEMBER 1, 1893. IMPROVEMENTS IN TELE-PHOTO LENSES, A coM.MUKiCATioN on the tele-photo lens, hy Mr. T. 11. Dall- meyer, which appeared ia our issue of July 28, has now been sufficiently long before our readers to enable them to note his statements. Since that time, we have been permitted to occupy the strong vantage-ground of being able to speak of the subject from the experimental point of view. While, in his earlier telephoto lenses, Mr. Dallmeyer seemed to have had in view solely those who aimed at an exceedingly high degree of magnification, in his new scries he has realised that there are many who do not care for the extreme of ampli- fication, but would be content with a moderate degree of direct enlarging. In this we think he is right. The former having been attended to, he has now turned his attention to the latter. While his general system of a compound amplifier, composed ' of a pair of achromatic concave lenses, has been adhered to, Mr. Dallmeyer has altered the internal structure of these concave appliances, and has pressed into his service certain properties obtainable only by the employment of Jena glass. His original concaves were composed of flint and crown glass, and were combined by what is known indiscriminately as the Gauss or (Jrubb forms inverted. In this, it need scarcely now be said, the flint glass had a much higher degree of refraction than the crown, although the familiar jhapes of "crown" and " flint " arc reversed. But in the present one — and, so far as we can see, he has no more worlds to conquer in this direction — he has adopted a form of double combination, each separate com- bination having a contact between two separate lenses, one of which, although it has a higher refractive index than the other, is convex in shape, these contacts tending to a better cure of astigmatism. If this form were adopted for very high magnifying systems of this nature, the reverse curvature of the field introduced would be more than is allowable. If a power- ful negative lens be used, the reverse curvature of field is best remedied by the other form referred to. There are planes curved tomards the lens, planes flat and very nearly flat, and planes with " reverse " curvature, dependent upon the camera extension. In some cases an unsymmetrical form has been adopted in which there are two planes of perfect flatness at considerably different extensions, this being arrived at by reversing the negative combination in its cell. The practical result of this is that a lens much larger in diameter can be employed, transmitting a ray of light consider- ably exceeding in obliquity anything previously obtained ; that the astigmatism of the oblique pencils caused by the front lens is annihilated or practically so ; and that the distortion of curvilinearity is done away with. This improved back concave or tele-phot) attachment can be employed in conjunction with any lens, whether a portrait combination or a rapid rectilinear. We have had it applied to a Petzval carte portrait combination of six inches focus, although warned by the maker that it was not by any means the best for such an attachment, and have found that by its agency (its diameter is nearly one and a half inches, and its focus, negatively, four inches) the old carle lens, which was corrected to cover a plate of three and a ((uarter inches, now covers a plate the full size capable of being contained in a 10x8 camera, the largest on which we have as yet tried it. In doing this there is so much light transmitted as to admit of the employment of a drop shutter in good light, or ihe giving of an exposure of from half a second to three seconds in light of a less intense character. The distance apart of the front positive system and the ■^back negative one is the factor which determines the magnitude of the image, of course taken in conjunction with the position of the focussing screen relative to both. No matter how much or how little the camera is extended, there is a relation between the two lens systems which, when ascertained and adjusted by actual trial, ensures sharpness. The smaller the separation of the positive and negative systems, the greater will be the magnification of the image, and the farther must the camera be extended. This cannot be explained by instituting a com- parison between it and the ordinary cimera and lens in which, if the focussing screen be placed either within or without the focus, the image will be blurred without the power of being sharpened. But an analogy exists between it and the screen of the optical lantern, on which to project an enlarged image. An equally sharp result is not obtained on a screen shifted from the twelve-feet position on which the focus had been adjusted away to twenty or forty feet. But sh.arpncss at any distance is obtained by readjustment of the objective. And thus it is with the tele-photo objective. A slight manipu- lation of the rack and pinion ensures perfect shai-pness, no matter how much or how little the camera is expanded. This constitutes one of the beauties of the system of mounting that has been adopted, for, by its agency, the photo grapher can, within certain limits, make a distant object of any size he chooses either to cover a quarter-plate, or one of 12 x 10 inches or more in dimensions. A short time since an American optician applied for a pitent for a rigid tube in which to mount both positive and negative elements of a tele-photo objective. But from what we have said it will be seen that this adaptability of size of image to the space which it is found desirable to cover is totally wanting in such a system ; whereas, by that adopted by Mr. Dallmeyer, there is absolutely no practical limit to the dimensions to which an object at a distance may be carried. 654 TflE BKITISH JOURNAL OF PHOTOGRAPHY. [September 1, 1893. With regard to exposure, it will, of course, be well under- stood that, the greater the magnifying of the image, the less is the rapidity, seeing the intensity of the lens is reduced by magnification ; so that, according to the intensity of the entire instrument, must one determine for himself whether he will choose a positive lens, per »e, of liigh or moderate intensity. DISCOLOURED NEGATIVES. In spite of all that has been written in these columns and elsewhere on the subject of imperfect fixation, we are con- stantly being asked to explain the cause of, and supply a remedy for, discolouration in negatives, that can only be traced to the want of the most ordinary care in treatment during and after fixing. In most instances, by the time the evil has been recognised, it has become irremediable, although, if taken in time, it is often possible to arrest its further progress or even to remove any slight discolouration that may have occurred. There are many different forms in which this discolouration may arise, and, although they may one and all be traceable, in the first place, to imperfect fixation, or insufficient washing afterwards, yet it does not follow that the immediate result is the same in all cases. For instance, we may have a negative whicli shows a yellow discolouration as soon as it is dry, or perhaps even before that, and then, again, may exhibit signs of change soon after it is put into the printing frame, while others only develop the fault in the course of weeks or months, and quite independently of whether they are exposed to light or not. Quite another kind of discolouration is met with in the case of negatives that have shown no symptoms of the evil, until, for one reason or another, intensification is resorted to, when it appears in full force. The chemistry of the changes that occur has never, so far as we are aware, been carefully studied in connexion with gelatine films, and the result is set down, in a general way, to sulphura- tion in some form or other ; but that it is the same in all cases is, we think, far from true. In one class of cases the image itself is involved in the change that goes on, while in others the discolouration appears to be confined chiefly to the film of gelatine. In some instances, too, the colouration is removable, while in others it resists every attempt to get rid of it. If we glance briefly at the chemical changes that are supposed to go on in the process of fixing, it is not difficult to under- stand that the after-discolouration may partake of different characters. The nature of the double salts formed under vary- ing conditions has been over and over again pointed out ; for instance, it is known that, with a weak fixing bath, or when in- sufficient time is allowed, an insoluble silver compound is formed, which, with a stronger bath, or under more prolonged action, is converted into a more soluble form, which is remov- able by washing. It is here where the distinction between imperfect fixing and imperfect washing comes in, the two being only too frequently confounded or considered synonymous. In the case of an imperfectly fixed negative — that is, one from which the unaltered bromide of silver has been barely removed, and which is apparently fixed — there will still remain in the film a quantity of silver, either in an insoluble form, or, what is practically equivalent to it, in a state in which it is ■precipitated or rendered insoluble by washing. On the other hand, the perfectly or sufficiently fixed film may contain, like the other, a quantity of silver ; but it is in the soluble form, and is not precipitated in the course of washing, but may be- entirely eliminated if the washing be properly performed. This constitutes the essential difference between imperfect fixing and washing. It may be accepted, we think, as an undoubted fact that, in order to have discolouration of the film from the action of hypo, there must be silver present in some form, as the hypo- itself will not stain the gelatine. The familiar term " sulphura- tion " as applied to prints or negatives describes the effect produced by the combination of silver and sulphur, these being supplied by the unremoved products of fixation. Sulphur, or rather hypo, alone will not produce the result, as has been proved by immersing a perfectly fixed and washed print in a fresh solution of hypo. The extent and nature of the dis- colouration will depend upon whether the silver is present in the soluble or insoluble form, or, in other words, whether the fault is insufficient washing or imperfect fixing. If a plate be cut in halves before fixing, some instructive light may be thrown upon the matter. Let the two halves be placed together in the hypo bath, and allowed to remain until the silver haloids have just disappeared and no more, then let one half be taken out and washed very thoroughly, the second half being allowed to remain for a further period equal to that already given, and then simply rinsed sufficiently to prevent crystallisation of the superfluous hypo on the surface. If the two halves be carefully preserved from the action of light until quite dry, they will probably show no sign of anything abnormal, unless, perhaps, in the case of the portion which has received the shorter immersion in the fixing bath, there may be some slight opalescence, especially if the film be thick • but, directly they are taken out into a strong light, tliey will both be found to discolour, assuming a yellowish brown tinge of greater or less depth, according to circumstances. But, in the case of the shorter fixing, the discolouration will be denser, and of a more opaque character than the other which will be clear and transparent, and apparently confined to the shadows of the negative, whereas, in the first case, the change of colour appears to affect the image itself, and to alter its density. If, instead of immediate exposure to light, the two portions of the negative be carefully put away in a dark place for some weeks, it will be found on examination that while the imperfectly fixed portion remains unchanged in appearance, the other will have undergone spontaneous dis- colouration in much the same manner as under the action of light. Assuming that both halves have been equally protected from abnormal atmospheric conditions likely to bring about decomposition, these two experiments show that there are in- fluences at work quite distinct from sulphuration as commonly understood, and that the effect produced differs according to whether the silver is present in the form of the insoluble or the soluble double hyposulphite ; for, while both are sensitive- to light, it is found that the latter is more liable to spontaneous decomposition in the presence of gelatine. This is quite as might be anticipated, if we consider the behaviour of gelatine after treatment with, or in the presence of, a soluble silver salt such as the nitrate. It is not our purpose to enter into the question of the ultimate changes that would occur under circumstances favour- able to "sulphuration," suffice it to say that either of the plates mentioned would exhibit it in its worst form. What we particularly wish to point out is how the two faults, imperfect fixing and washing, may be recognised and', remedied if taken> tf September 1. 1803] THE BRITISH JOURNAL OF PHOTOGRAPHY. 666 •in time. It will be readily understood that both may be •present in the same plate ; and, though the proper treatment ^br one is not the correct remedy for the other, still, means may be adopted that will effectually cure both. In actual practice it is surely seldom that the work is so ■ carelessly performed that the wliole surface of a negative suffers from either of these forms of neglect. The results are generally seen in the form of patches, arising from inequalities or irregularity in the thickness of the films, against which it is often impossible for the most careful operator to guard ; but, by carefully examining his negatives after drying, and especi- ally after exposure in the printing frame, he will often be able to detect the evil in its incipient form, and arrest its further progress. The result of imperfect fixation is, as we have said, some- -times visible in the form of a slight opalescence before exposure to light, and this is more especially the case when it occurs in patches. When thus apparent, it is easily removed by re- immcrsion in a fresh solution of hypo. If, however, the nega- tive be exposed to strong light before the discovery is made, ■more or less discolouration will take place, and] this will be intensified by each successive exposure. All that can be done amder these circumstances is to arrest the further progress of the decomposition by refixing, and if this be done at once the injury will not be great. But a negative may be perfectly clear and free from opales- cence before exposure in the printing frame and yet show in a -sliort time a clear yellow stain, generally along one edge or over one corner. Reimmersion in the fixing bath if done at once will often remove this, especially if it be simply the result of insufficient washing. But it is seldom that either fault exists alone, and, in order to satisfactorily treat both, the best plan we have found is to soak the film first of all for two or three minutes in a strong plain solution of salt, and then with- out washing to plunge it into a dish containing a very dilute solution of nitric acid, about fifteen or twenty mimims to the ounce ; after this, wash to remove the acid, and refix and wash in the usual way, when in nine cases out of ten the stain will have disappeared. But, after all, prevention is better than cure, and it is a very «asy matter, without adding greatly to the trouble of finishing a negative, to test whether it is properly fixed and washed be- sfore running any risk. All that is necessary, as we showed a 'few weeks back, is to immerse it in a solution of iodide of potassium, when any silver remaining is at once rendered •visible as iodide. KEEPING QUALITIES OF FILMS, Of late the question has been raised at several of the societies, :and at different times in our columns, as to the relative keeping •qualities of plates and flexible films, and diverse opinions ex- pressed. In our last two issues the subject is again referred to in letters from two well-known amateurs — Mr. W. J. Hillman and Mr. F. Beasley. In the majority of instances, when the question has been previously raised, several im- portant points in connexion with the subject have been entirely Jgnored, the various commercial films being 'treated almost as if they were a standard commodity. As a [consequence, the alleged deterioration, if any, has been attributed mainly to the support of the gelatino-bromide of silver. Glass may be fairly classed as being, so far as gelatino- tiromide of silver is concerned, a perfectly inert material. Yet we all know quite well that plates prepared with some emulsions will remain good for several years, while others, witli different ones, will sometimes become almost useless after only a few months' keeping. Tlierefore, in the consideration of this subject, it must be l)ome in mind that the emulsion itself is a most important factor in the case, quite independent of the material upon wliich it rests, whatever that may be. Then, again, flexible films themselves are not alike either in their composition or mode of manufacture, not even when they pass under the generic term celluloid, while some are of an entirely different material. Celluloid or, as the English manufactured article is named, xylonite, is a modification of what was at one time called, after the name of its inventor, Mr. A. Parkes, Parkesine. Numerous improvements have been made in it since, and many patents in connexion with the materials used and its manufacture, have from time to time been taken out, but whether all, or even any, of them are being worked we are unable to say. As a matter of fact, the whole of this manufacture is treated very much in the light of a trade secret, and its working is in the hands of a few large firms only. Indeed, we question if, in connexion with any material having so many applications, and being employed for so many general purposes, so little has been published with regard to the details of its manufac- ture. It is, however, safe to afiSrm that^it is essentially a com- pound of nitro-cellulose and camphor, although it may be made by different methods. According to one of the Eastman Com- pany's patents, their film is composed of soluble pyroxyline, camphor, wood naphtha, amyl-acetate — more familiarly known to some as essence of jargonelle pears — and fusil oil. The solution is spread on glass plates and allowed to dry, when it is coated with the emulsion. What are known as cut films are made quite differently. In this case the camphor is really the solvent of the nitro- cellulose, but this is not of the same kind as the soluble pyroxyline used for collodion, but a lower nitro compound known as xyloidine. It is almost insoluble in ether and alcohol, but when kneaded and rolled, camphor, by reason of the latter's solvent action, heat also being applied, becomes a plastic mass, which can be wrought in various ways. In con- nexion with the solvent action of camphor, it may be men- tioned that there are several substances that are not solvents of nitro-cellulose by themselves, but they become so by the admixture of camphor. AVhen required for such pxirposes as knife-handles, pianoforte keys, photographic dishes, 4, but not founded until a meeting of aseiutants was called in 1873, when a Photographers' benefit Society was established. M a later date it became purely benevolent. It does considerable good in a quiet way, derives most of its funds from manufacturers and amateurs, and dispense them entirely to professionals and assistants. Has been gene- rally neglected by the profession. Has a fund of nearly 400/. in hand, and has the making of a valuable insitution. fi. The AJTiliation of I'hotoyraphic Societies (Secretary) E. Child Bayley, 50, Great Russell-street, London, W.) An afliliation started by the Photographic Society of Great Britain, and consisting of a number of amateur and mixed societies, might prove a valuable factor in a comprehensive scheme of union. 7. ■/ he International Photoflraphic Congress. — Suggested by the jury of the Brussels Photographic Exhibition, 1885. Initiated in 188fi, with the King of the Belgians as patron, but did not meet until 1889, when a Congress was held in connexion with the Paris Exhibition. A second Congress was held in Brussels in 1891. On both occasions large Congresses of the best-known photographers devoted several hours a day for several days to the careful discussion of various practical questions, and made recommendations as to standards, riuting as with an ordinary negative. The unexposeil portions may be further exposed, and the after effects done on the negative before development in the followihg manner ;— A thin card replique of the al)ove screen, without any discs, must tirst be placed in the dark slide, angled to secure future correctness always in one, say, tlie left-hand corner of the slide, and upon it, also angled in the same corner, is placed a sensitive plate. It is exposed to gas, or diffused light, anil developed. When dry it is kept for future use for any number of plates, and is the shield of that particular series. The same replique must be again angled in the same comer, and a sensitive plate, similarly angled, placed upon it. The exposures being made, the plate is lifted in the dark room, auu the card replique replaced by shields, both plates being angled as before. The series of developed discs on the shield fit accurately the exposed portions of the superimposed plate, and protect the portraits from the momentary exposure to gas. Subsidiary effects can be introduced by paper negatives or positives, litho prints or devices, signatures, mottoes, birth-dates, and the like, by interjiosing before the exposure to gas, the position being easily determined by fitting the same on the shield by day- light. Each camera will require a special frame or holder fitted in to receive and hold the new screen. The supplementary exposure need not necessarily be made in the same dark slide ; any will do, provided that the shield be angled in the left corner, and the exposed plate similarly angled on transfer from its proper dark slide. An Improvkmbst in thk Manufactcbe of SKNsrrivK Plates or Films for Photoorafhic Purposes. No. 12,304. Francis William Edwards, 87, Belleuden-road, Pechara Rye, S.E., and Harry Ransom, 122, Newington-butts, S.E. — Jidy 22, 1893. Odr invention relates to an improvement in the manufacture of sensitive plates for photographic purposes, and its object is to give a grain, stipple, or line to the pictures printed therefrom, and also to diminish the liability to halation and solarisation (or reversal of the image), which are incidental to photographic plates prepared in the ordinary way. By employing plates made according to our invention, it is possible to pro- duce photographs in which the subject ai>pears as a series of fine lines or dots, instead of tne usual flat tones, thus obtaining in the one operation of printing the special character required for photo-mechanical reproductions. Our invention consists in giving to the surface of the sensitive film, or its support, a series of fine lines or dots by any of the ordinary printing or sten- cilling methods, preferably by a specially prepared roller, or a perforated plate. These lines or dots, consisting of a suitable medium, will thus allow the action of the light on tlie sensitive parts only, and hence the resulting negative will appear as a series of fine lines or dots. By this method of graining the negative, with a medium easily removable, in whole or in part, after development, the light and shade of the print can be modified as required. This lining or graining of the sensitive surface will also have a tendency to break up the rays of light reflected from the surface of the support of the sen- sitive medium, and thus prevent halation or solarisation. The claim is : — The preparation of sensitive photographic plates or films, with a grained, dotted, stippled, or lined surface, such lining or stippling con- sisting of any suitable medium applied by any mechanical or other method. The Ejiploymest of Diamidodioxtbenzol vs Combination with Sulphites OF THE ALKAUES FOR DEVELOPING THE LATENT IMAGE IN LAYERS CON- TAINING Halogen Silver for Photographic Purposes. No. 22,576. Julius Haufp, Fenerbach, near Stuttgart, Germany. July 22, 1893. This invention relates to the employment of diamidodioxybenzol for develop- ing the latent image in layers containing halogen silver for photographic pur- poses, consisting in dissolving, in suitable proportion, in water, diamidodioxy- benzol with soluble sulphites, or with .soluble acid sulphites, to which latter if added the quantity of soluble bases or carbonates required for the purpose of neutralisation, so as to obtain solutions ready for developing purposes, the action of these solutions being intensified by the addition of a few drops of preferably a five per cent, solution of a carbonate of the alkalies, and enfeebled by the addition of a few drops of an acid solution, or of a few drops of a solu- tion of bromide of potassium. The orthoamido compounds of the phenols and cresols have not yet been utilised as developing substances for photographic purposes, nor have they been as yet included in patents referring to such purposes. Without the use of caustic or carbonated alkalies, they are too weak bodies for reduction purposes in order to bring out the latent image, while, if such chemicals are used, they are too energetic as reducing means, and impart a black colour to the whole image. As a result of my experiments on the preparation of such developing sub- stances which develop the image in weak acid or neutral solution, I have dis- covered that, by introducing a further amido group in amidophenols which only operate in alkaline solutions, these amidophenols will be able to develop with sulphites only, and that my opinion is capable of the most extensive generalisation. The chief representative of this new group of developing sub- stances is the already patented diamidophenol, which gave me, since the short time that it has made its appearance in the market, the most conclusive proof of its sterling properties for developing purjwses. The theoretical testing of other substances under consideration led me to the thought that, by doubling the OH ; NH2=1 -.I group in the benzol kernel, I mav be able to likewise double the developing power, which is not very great, if "the above-mentioned orthoamido compounds are employed for developing without carbonates of the alkalies, so that the said orthoamido compounds may be able to develop the image with sulphites only. In testing these orthoamido compounds. the anbutMice of the following coiutitutioa prMentwI themiatviM in th« flnt place : — OH OH NH> NH' that is to say. a diamidodioxybenzol, with two hydrozylamido groapt existiog together in the ortho arrangement As a matter of fact, tbii compound i« ■ very advantageous developing means, which, without the use of^caoatic or carbonated alkalies, slowly developea the latent image in from three to four minutes, with a deep coating and fine details or ouuines. It develops much more slowly than the diamidophenol developing agent, a fact which may be already expected from the other grouping of the developing rsdicala. For many purposes, however, this is a distinct advantage over the diamido- phenol developing agent to which I have given in commerce the name of amidol. Moreover, the new developing means nnites the advantage of the dihydroxyl developing means, i.e. . a deep black colour, and covering with the advantage of the hydroxylamido developing means, that is to say, clear work, sharply outlined in all its details, and entirely free from must or haze, without recjuiring the use of caustic or carbonated alkalies, which are injnrioua at mans points of view. EXAMPLS. In 100 parts of water I dissolve 0-5 parts of diamidodihydroxybenzol and eight parts of crystallised sulphite of soda. With this solution, several successive developments may be effected. To intensify this development, I may use a concentrated solution of a sulphite or a few drops of a five i)er cent, solution of potash in water, whereas, to retartl the development, a few drops of an acid, or of a five per cent, solution of bromide of potassium, may be used. To obtain greater durability for the solution, I may use. instead of a neutral sulphite, an acid sulphite of soda, only it would be necessary in such a case to add, before developing, the required quantity of a base, or of a soluble car- bonate, to neutralise the double sulphite of soda. The claim is : — The employment of diamidodioxybenzol for developing the latent image in layers containing halogen silver for photographic purposes, con- sisting in dissolving, in suitable proportions, in water, diamidodioxybenzol with soluble sulphites, or with soluble acid sulphites, to which latter is added the quantity of soluble bases or carbonates required for the purpose of neu- tralisation, so as to obtain solutions ready for developing purposes, the action of these solutions Ijeing intensified by the addition of a few drops of preferably a five per cent, solution of a carbonate of the alkalies, and enfeebled by the addition of a few drops of an acid solution, or of a few drops of a solution of bromide of potassium. ifle^tinsiS of 5boctf tieiS. MEETINGS OF SOCIETIES FOR NEXT WEEK. Date ol HeotlDg. September 4.. „ *.. :: t: „ 4.. :; 5.: :: i::: .. 5.., 5... 5... S- 6... „ 6... :: i::: .. 5.. 6... „ 8... „ 6... » •>■•■ 7... 7... 7... :: ?::: >* 7... 7... 8... 8... 8... 8... 8... .■ 8... 8... 8... Name of Society. Dnndee Amateur. Peterborough Putney Richmond South London , Stereoacopic Club , Birmingham Photo. Societj ... Brixton and Clapham Exeter Hackney Herefordshire Lewe-i (Annual) North Loudon Oxford Photo. Society Paialey Rothcrham Sheffield Photo. Society York Leytonstoue Photographic Club Southport Southaea Wallasey Birmingfaiun Photo. Society ... Glossop Dale HoU Leeds Photo. Society London and Provincial Oldham Tunbridife Wells Bristol and West of Bngland ... Cardiff Croydon Microscopical Halifax Camera Clab i Holbom Ireland i Maidstone West London HuU Pla«« of Meeting. Abso. Studio, Nethergate, Dundee. Museum, Minster Precincts. High-street, Putney. Greyhound Hotel, Richmond. Hanover Hall, Hanorer^park, S.B. Brooklands Hotel, Brooklands. Club Room, Colonnade Hotel. 376, Coldharbonr-l&ne, Brixtou. City Chambers, Ckindr-st., Exeter. 206, Mare-street, Hackney. Mansion House, Hereford. Fitzroy Library, High-st., Lewe«. Canonbnry Tower, laUngton, N. Society's Rooms, 136, High-street. 9, Gauze-street, Paisley. 5, Frederick-street, Eotherham. Masonio Hall, Surrey-street, Victoria Hall, Goodramgate, York. The Assembly Room.i, High-road. Anderton'a Hotel, FIeet-street.B.C. The Studio, 15, Carabridge-aroado. 3, King's-road. Southsea. Egremont lustitnte, Bgremont. Club Boom, Colonnade HoteL 71, Prospect-street, Hull. Mechanics' Institute, Leeds. Oluunpion Hotel, 15, Aldenvate-st. The Lyceum, Union-street, Oldham. Mechanics' Inst.,Tunbridgn Wells. Booms, 28, Berkeley^sq., BristoL Public Hall,0«orge-street,C roydoa. Booms, 15, Dawion-ctreet, Dahlia. ** The Palaoe," Maiditona. Ohiswiok School of Art, Ohiswiek.- 71, Prospeot-stTMt, HaU. 6G6 THE BRITISH JOUKNAL OF PHOTOGRAPHY. [September 1' 1893 LONDON AND PROVINCIAL PHOTOGRAPHIC ASSOCIATION. AUGCST 24.— Mr. E. H. Biyston in the chair. _ , The Hon Secretary passed round an album containing views of the lower oi liondon, which he hii'd recently taken as a guide, to the members visiting there on the following Saturday. Metol and Gltoin. The subject of the evening, "Demonstration by Mr. Morgan {Messrs. Fuerst Bros ) of Development by Metol and Glycin," then commenced. Mr Morgan said that as glvcin was slow and peculiar in its action, antt -therefore not a fit subject for demonstration in public, he would proceed at once with metol, which he said was a suitable developer for br»mide prints, negatives, and lantern slides. The mixed developer did not stam tlie hngers, although the dry powder would do so. The solutions used and recommenaea "Were as under : — Solution A. Water 100 parts. Metol ,lP*L Soda sulphite 10 parts. Solution B. Water 100 parts. Carbonate potash (or substitute) 10 „ Crystallised carbonate soda 20 „ 3 parts A to 1 of B. with 40 minims of bromide of ])otassium solution (1 : 10) Metol had a great advantage over other developers, inasmuch as it would keep indefinitely, even as a one-solution developer mixed with free alkali. The ex- ■posnre was stated to be only one-half of that for pyro. With a normal expo- sure, the image comes up quickly ; but the operator must not be frightened, 'but allow it to go on until density has been obtained ; the shadows will always remain clear. Two negatives were passed round, one developed with pyro and one with metol, also prints therefrom. Mr. Morgan then successfully developed a portrait negative exposed that afternoon at thirty minutes past three (half a second with /-ll), also a bromide (print and lantern slide, the latter being developed with the same solution as the bromide. Answering a question, Mr. Morgan said he always used half a grain per -ounce of soluble bromide. Mr. W. E. Debexham said it was a pity that the two negatives shown were ■not the same density, so that no strict comparison was possible. The same claim of lessening the exposure had been made for all the new developers, and if in this case it could be substantiated, then metol would be the best ■developer we had. Mr. EvERiTT said that, of the two negatives one was yellow and the other blue ; also, that by printing on gelatino-chloride paper the thinner one was favoured. Platinum would have been better for the pyro print. The Chairman remarked that by not giving the same exposure the advantage in this direction was not proved. Mr. EvERiTT suggested test-exposures as between pyro and metol — that is, stepped exposures to a standard light. Mr. Debenham suggested the reproduction of a negative by a standard light in order to corroborate the other experiments. Mr. Morgan said that the pyro negative passed round was exposed and developed in normal time with a normal developer. The metol one was ex- posed simply one-half the time, and resulted in better gradation and longer scale. Mr. Fry said that he could not agree with Mr. Morgan on the question of exposure. He liked colour in a negative, and not a blue one. If a pyro negative was under-timed, then a hard result was obtained ; but, with metol and amidol, the negative was thin, and might give a passable print. He thought that a false conclusion had been arrived at. Mr. Deage saw a great advantage in the cleanliness of metoL It could be used four or five times. Mr. Morgan had developed eight half-plates in the same two ounces of solu- tion, when the last was the same as the first. The Chairman in proposing a vote of thanks to the demonstrator said he liked metol, as it was clean and useful, except for negative work. This was carried by acclamation, .ind Mr. Morgan briefly responded. In answer to a question by Mr. Haddon respecting " Pepperine," introduced some years ago, Mr. Bolas said particulars would be found in The British Journal op Photography, about 1886. He believed it was an alcoholic tincture of pepper. Hactaxey Photographic Society. — August 22, Mr. Beckett in the chair. — Mr. Eoder showed a print he had toned using carbonate of soda, but it was not clear. Mr. T. H. Smith showed some work done on Nikko paper, with which he was much pleased. Mr. Roofe had used metol, and obtained plenty of density, Mr. Nunn complaining of lack of colour in amidol. Mr. Miller, of the South London Society, then gave an interesting account of photographic mirrors, finally concluding with a demonstration of how to do it. For reversing work, mirrors are very useful, and for zinc an absolute necessity. Mirror making was best done in the daylight. The glass must be chemically clean, and ought to be optically worked. The bath must be under 60°, and distilled water must be used. The solutions used were ten per cent, solution of white loaf-sugar in distilled water, and to it one-tenth part ordinary alcohol and one-half per cent, nitric acid. Take three ounces of solution, and add four ounces of distilled water, and to this, in turn, seven drachms of reducing solution, made up of ten per cent, of nitrate of silver. Add drop by drop to bath mentioned until precipitate is formed, which redissolve by gradually adding ammonia. Then add three-quarter ounce of ten per cent, freshly made solution of caustic potash. Then add more ammonia as before, and, when cleared, it is ready for use. In twenty minutes glass will be coated, which must be first washed in acid, fdllowed by distilled water, and dried in blotting-paper. East London Photographic Society.— General Meeting, Mr. Uffendall in the chair. — Mr. Bennett read a paper Upon the Desirability of Adapting the Printing Process to the Subject and Quality of the Kegatice. The lecturer illustrated his remarks with some prints, showing that what would make a good picture upon one kind of paper, upon another would be an utter failure. He remarked upon the disappearance from the walls of the exhibitions of pic- tures printed upon the albumenised paper, and said that the impurities and unstapleness of the paper was the reason. He congratulated the present gene- ration of photographers upon the advantage theif have over those of the past, inasmuch that, whilst the older generations only had the one process, the pre- sent had an almost unlimited choice. He further said that the aim of all should be to portray, as accurately as possible in the finished print, the natural tone of the subject which forms the negative, for, by so striving to this end, we are distinctly upon the threshold of colour iihotography. In con- clusion, he said that the following maxims should not be forgotten :— " Never print from a weak negative upon a paper which is adapted more particularly to one of greater contrasts ; " " Let your print be finished ofl' in such a way as to harmonise with the subject ; " ancl, lastly, keeping this well in mind, "that colour, like distance, lends enchantment to the view," and only by a careful study of the several points can we attain to anything approacliing perfection, and justify our claim (though by many it is disputed) that photography is an art. Croydon Camera Club. — A whole day devoted to practical photography in the field was spent by a party of the members under the guidance of the Presi- dent (Mr. H. Maclean, F.G.S.) on August 23, the locality chosen being on the borders of Ashdown Forest. In the course of the day the ruins of Brambletye were visited ; the Medway, which is here little more than a runnel, neverthe- less afforded subject matter for several views. The village of Forest Row, con- taining a number of old timbered, and also some stone-roofed cottages, re- ceived due attention. In the after part of the day Mr. Maclean gave a practical demonstration in composition, the subject being The Wood-xnorkers. Later, VVych Cross was reached, and members being by this time somewhat s,atiated with the scenic attractions, a pleasant tramp back through the forest glades and over the golf links to the Brambletye Arms was made. Birmlnghajn Photographic Society.— August 22, the President (Sir J. B. Stone) in the chair. — The President distributed to the successful competitors the prizes and certificates gained at the last annual exhibition. In the course of a few well-chosen remarks, he said that personally he deprecated the giving of any prizes, from the point of view that it was almost impossible for judges, however skilled, to decide whicli were the absolutely best pictures, some being superior in technique, some in artistic feeling. Let photography be a useful record, not a mere striving after prizes. The President congratulated the members on the second Warwickshire Survey Exhibition, now being held in the Corporation Art Gallery, and bade them continue with this useful move- ment. FORTHCOMING EXHIBITIONS. 1893. Septembers *Royal Cornwall Polytechnic Society, Falmouth. W, Brooks, Laurel Villa, Wray-park, Reigate. „ 20-21 *Hove Camera Club. Hon. Secretary, H. Emery, 142, Church-road, Hove, Brighton, ,, 25-Nov. 15... *Photographic Society of Great Britain, 5a, Pall Mall East, S.W. Assistant Secretary, R. Child-Bay ley, 50, Great Russell-street, W.C. October 1-31 'Hamburg. Das Ausstellungs Comraitte des Amateur Photogi-ajihen Verein, Schwanenwik, 33, Hamburg. ,, 9-Nov. ... "Photographic Salon, Dudley Gallery, Piccadilly, W. Hon. Secretary of Organizing Committee, A. Maskell, 215, Shaftesbury-avenue, W.C. November 7-11 *South London Photographic Society. Hon. Secretary C. H. Oakden, 53, Melbourne-grove, Dulwich, S.B. ,, 20-25 *Leytonstone Camera Club. Hon. Secretary, A. K Bailey, Rose Bank, South-west-road, Leytonstone. December *Madras. The Hon. Secretary Amateur Photographic Society, Madras. * Signifies that there are open classes. « €orresf|)onlrence. ' Oorreaji undents should never vrrite on hoth sidea of the paper. No notice is taken of communicatioru unless the names and oddres8e« of the writers are given. COLOUR PEINTINa IN HALF TONES. To the Editor. Sir, — In your " American Notes and News," p. 543, you state that Kurtz, of New York, has " patented a process of printing half-tones in colours by carrying out the idea of the three primary colours, and using blocks in which tlie grain runs in lines of different directions." If this is a fact, Mr. Kurtz is making a bold attempt to appropriate a method which I devised and carried out successfully twelve years ago. Nobody seemed to be able to realise the significance of such a result by such a method at that time; but when I exhibited the same reproduction at the Novelties Exhibition in Philadelphia in 1885 it received some notices in the local newspapers, and I remember that one of these notices was 1 reproduced in one or more of the photographic journals. September 1, 1893] THE BRITISH JOURNAL OP PHOTOGRATilY. 867 The specimen referred to — a reproduction of a ohromolithosraph, accompanied by printed descriptive matter — occupied a coDspiouons position by tlie side o( exhibits of my patent lialf-tone block process and ohloropliyl process of ortlioohromatio photography. Mr. Kurtz had an exhibit of portrait work in tlie same section, a few feet away, and I have no doubt tliat he saw and studied this reproduction by a method which he now claims as new and original. Mr. Kurtz's recent specimens are more remarkable than the one I made in 1881, chiefly because he selected more striking subjects, made larger plates, and printed on enamelled paper, which does not deprive the coloured inks of their gloss and transparency like the soft plate paper universally used for fine printing in 1881. If this process had been really capable of successful commercial operation on a large scale, the firm with which I was connected would have gone into it ten years ago ; but while it is possible to produce wonderfully effective specimen prints, the quality of the work becomes so uneven and generally bad under the present conditions of commercial printing, that it does not give satisfaction even when the printing plates are perfect. A striking proof of this is found in the result of the Kurtz Company's first attempt to illustrate a periodical with reproductions of colour sketches supplied by the publishers for the purpose. In the " Outing" number of Tlie Chriiitinn Viiioii (New York), June 10, p. 1148, some of Mr. F. Hopkinson Smith's beautiful colour sketches of the scenery of the Bronx Biver are " reproduced," in a manner that must have surprised the artist, to say the least. I would advise anybody who contemplates undertaking this kind of work to see these results before doing so, and I would also like to know the Editor's opinion of them.— I am, yours,