^ i A^ 
 
 
 
 
 
 ■*JC J' A~ ^ 3-^>x •ygM-3 > J / 
 
 
 gp 
 
 
 
 vfc-TV'. 
 
 g5§^ 
 
 
 
 
 
 
 
 
 
 
 
 ^ a ^*^^^V\.fi^A A L t jaj 
 
 
 
 
 
 
 
 
 
 
 
 
 lllll 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 ||j| 
 
 
 
 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 &£j 
 
 
 
 5* cn*>v*^» 
 
 
 
 
 ||£ 
 
 
 
 5$S 
 
 
 M. 
 
Digitized by the Internet Archive 
 in 2016 
 
 https://archive.org/details/lanternslidesbypOOprin 
 

M°(^WO(^MO(^MO(^MO(hWO(tWO(^[MO(hwO<pmO<^Wo/0MO(b^O<pWO(hWO(f;q)O(^0).O(^q)O(^ 
 
 THE S. & A. 
 
 PHOTOGRAPHIC I 
 1 SERIES. S 
 
 D>< 
 
 L5C 
 
 ^^(G^^{Q^^^^^^^oic^OK)Q)o<pd)oK)5)o(c9 0 iP9 0 ^P^ v °{0 9 o{pO)ort) Q)ok3Q^oW^^(P Q) < 
 
 No. 5. PHOTOGRAPHY WITH EMULSIONS. 
 
 By Capt. W. de W. Abney, R.E., F.R.S. A treatise on the theory and 
 practical working of Gelatine and Collodion Emulsion Processes. (Second 
 Edition.) Paper covers 75 
 
 No. 7. THE riODERN PRACTICE OF RETOUCHING. 
 
 As practiced by M. Piquepe, and other celebrated experts. (Ninth 
 Edition.) Paper' covers, 50 cents ; Library Edition 75 
 
 No. 8. THE SPANISH EDITION OF HOW TO MAKE PICTURES. 
 
 Ligeras Lecciones sobre Fotografia Dedicados a los Aficionados, Cloth 
 bound, 75 cents. Paper covers 5° 
 
 No. 12. HARDWICH’S PHOTOGRAPHIC CHEMISTRY. 
 
 A manual of Photographic Chemistry, theoretical and practical. (Ninth 
 Edition.) Edited by J. Traill Taylor. Leatherette binding 2 00 
 
 No. 13. TWELVE ELEMENTARY LESSONS ON SILVER PRINTING. 
 
 (Second Edition.) Paper covers, 50 
 
 No. 14. ABOUT PHOTOGRAPHY AND PHOTOGRAPHERS. 
 
 A series of interesting essays for the studio and study, to which is added 
 European Rambles with a Camera. By H. Baden Pritchard, F.C.S. 
 Paper covers, 50 cents. Cloth bound 75 
 
 No. 15. THE CHEMICAL EFFECT OF THE SPECTRUM. 
 
 By Dr. J. M. Eder. Cloth bound, 50 cents. Paper covers 25 
 
 No. 16. PICTURE MAKING BY PHOTOGRAPHY. 
 
 By H. P. Robinson, author of Pictorial Effect in Photography. Written 
 in popular form and finely illustrated. Library Edition, $1.00. Paper 
 covers 75 
 
 No. 21. THE AMERICAN ANNUAL OF PHOTOGRAPHY AND 
 PHOTOGRAPHIC TIMES ALHANAC FOR 1887. 
 
 (Second Edition.) Paper cover (postage, 12 cents additional) o 50 
 
 Library Edition (postage, 12 cents additional) 1 00 
 
 No. 22. PHOTOGRAPHIC PRINTING METHODS. 
 
 By the Rev. W. H. Burbank. A Practical Guide to the Professional and 
 Amateur Worker. (Third Edition.) Paper only 75 
 
 No. 23. A HISTORY OF PHOTOGRAPHY. 
 
 Written as a practical guide and an introduction to its latest developments. 
 By W. Jerome Harrison, F.G.S., and containing a frontispiece of the 
 author. Cloth bound 1 00 
 
 No. 24. THE AHERICAN ANNUAL OF PHOTOGRAPHY AND 
 PHOTOGRAPHIC TIMES ALHANAC FOR 1888. 
 
 Illustrated. (Second Edition.) Paper (by mail, 12 cents additional) 50 
 Library Edition (by mail, 12 cents additional) 1 00 
 
 No. 25. THE PHOTOGRAPHIC NEGATIVE. 
 
 A Practical Guide to the Preparation of Sensitive Surfaces by the Calotype, 
 Albumen, Collodion, and Gelatine Processes, on Glass and Paper, with 
 Supplementary Chapter on Development, etc., by the Rev. W. H. Burbank. 
 Cloth bound. Reduced from $1.50 to $1 00 
 
The S. & A. Photographic Series. 
 
 No. 26. THE PHOTOGRAPHIC INSTRUCTOR FOR THE 
 PROFESSIONAL AND AMATEUR. 
 
 Being the comprehensive series of Practical Lessons issued to the Students 
 of the Chautauqua School of Photography. Revised and enlarged. Edited 
 by W. I. Lincoln Adams, with an Appendix by Prof. Chas. Ehrmann. 
 
 (Sixth Edition.) Paper covers 1 00 
 
 Library Edition 1 50 
 
 No. 27. LETTERS ON LANDSCAPE PHOTOGRAPHY. 
 
 By H. P. Robinson. Finely illustrated from the author’s own photographs 
 and containing a Photogravure frontispiece of the author. Cloth bound. 
 
 I 50 
 
 No. 29. THE PROCESSES OF PURE PHOTOGRAPHY. 
 
 By W. K. Burton and Andrew Pringle. A standard work, very complete 
 and freely illustrated. Price, in paper covers, $2 00. Library Ed., 2 50 
 
 No. 30. PICTORIAL EFFECT IN PHOTOGRAPHY. 
 
 By H. P. Robinson. A new edition. Illustrated. Mr. Robinson’s first 
 and best work. Cloth bound 1 50 
 
 No. 32. PRACTICAL PHOTO=MICROGRAPHY. 
 
 By Andrew Pringle. Fully illustrated. Cloth bound 2 50 
 
 No. 33. THE AHERICAN ANNUAL OF PHOTOGRAPHY AND 
 PHOTOGRAPHIC TIMES ALHANAC FOR 1890. 
 
 Paper cover (by mail, 14 cents additional) 50 
 
 Library Edition (by mail, 14 cents additional) I 00 
 
 No. 34. THE OPTICAL LANTERN. 
 
 Illustrated. By Andrew Pringle. Paper covers, $1.00. 
 
 Cloth bound I 50 
 
 No. 35. LANTERN SLIDES BY PHOTOGRAPHIC METHODS. 
 
 By Andrew Pringle. Paper covers, 75 cents. Cloth bound 1 25 
 
 No. 36. THE AHERICAN ANNUAL OF PHOTOGRAPHY AND 
 PHOTOGRAPHIC TIHES ALHANAC FOR 1891. 
 
 Paper covers (by mail, 15 cents additional) 50 
 
 Library Edition (by mail, 15 cents additional) 1 00 
 
 Cyclopaedic Index for 1891 Annual 10 
 
 No. 37 - PHOTOGRAPHIC OPTICS. 
 
 A Text-Book for the Professional and Amateur. By W. K. Burton. 
 Paper covers, $i.oo. Library Edition I 50 
 
 No. 38. PHOTOGRAPHIC REPRODUCTION PROCESSES. 
 
 Illustrated. By P. C. Duchochois. Paper covers, $1.00. Cloth... I 50 
 
 No. 39. EL INSTRUCTOR FOTOGRAFICO 
 
 Paper covers, $1.00. Library Edition : I 50 
 
 No. 41. THE CHEMISTRY OF PHOTOGRAPHY. 
 
 By W. Jerome Harrison. Cloth bound 3 00 
 
 No. 42. PICTURE flAKING IN THE STUDIO. 
 
 By H. P. Robinson. Paper Covers, 50 cents. Cloth bound (Library 
 Edition) 1 00 
 
 No. 43. THE AMERICAN ANNUAL OF PHOTOGRAPHY AND 
 PHOTOGRAPHIC TIMES ALMANAC FOR 5893. 
 
 Edited by W. I. Lincoln Adams. 
 
 Paper covers (postage extra, 15 cents) 50 
 
 Cloth bound (Library Edition) (postage extra, 15 cents) 1 00 
 
The S. & A. Photographic Series 
 
 No. 44. THE LIGHTING IN THE PHOTOGRAPHIC STUDIO. 
 
 By P. C. Duchochois. A new edition. Paper covers, 75 cents. Cloth 
 bound (Library Edition) 1 00 
 
 No. 45. THE GRAMMAR OF PHOTO-ENGRAVING. 
 
 By H. D. Farquhar. Illustrated. The most complete text-book yet pub- 
 lished on this subject. Price, in paper covers, $2.00. Cloth bound 
 (Library Edition) 2 50 
 
 No. 46. INDUSTRIAL PHOTOGRAPHY. 
 
 Illustrated. By P. C. Duchochois. Being a description of the various 
 processes of producing Indestructible Photographic Images on Glass, Por- 
 celain, Metal, and many other substances. Paper covers, 50 cents. Cloth 
 
 bound 1 00 
 
 No. 47. THE AMERICAN ANNUAL OF PHOTOGRAPHY AND 
 PHOTOGRAPHIC TIMES ALMANAC FOR 1894. 
 
 Edited by W. I. Lincoln Adams and Walter E. Woodbury. 
 
 Paper covers (postage extra, i 5 cents) 50 
 
 Cloth bound (Library Edition) (postage extra, 15 cents) 1 00 
 
 No. 48. ARISTOTYPES AND HOW TO MAKE THEH. 
 
 Giving a complete description of the manufacture and treatment of Gelatino 
 and Collodio-Chloride Papers. By Walter E. Woodbury. Illustrated. 
 Paper covers, $1.50. Library Edition 2 00 
 
 No. 49. THE ENCYCLOPAEDIC DICTIONARY OF PHOTOGRAPHY* 
 
 Containing over 2,000 references and about 400 illustrations. By Walter 
 E. Woodbury. In. preparation. 
 
 No. 50. THE AMERICAN ANNUAL OF PHOTOGRAPHY AND 
 PHOTOGRAPHIC TIMES ALMANAC FOR 1895. 
 
 With over 200 illustrations. Edited by Walter E. Woodbury, Editor of 
 “ The Photographic Times.” Paper covers, 50 cents (postage extra). Cloth 
 bound (Library Edition) (postage extra, 15 cents) I 00 
 
 No. 51. THE PHOTO-GRAVURE. 
 
 By Henry R. Blaney. A very complete and practical book, written by an 
 Expert. Paper covers, 50 cents. Cloth bound (Library Edition) ... 1 00 
 
 No. 52. THE PLATINOTYPE: ITS PREPARATION AND MANIPULATION. 
 
 By Capt. W. de W. Abney and Lionel Clark. Fully illustrated. 174 
 pages 1 25 
 
 No. 54. PHOTO-ENGRAVING BY THE ENAMEL PROCESS. 
 
 By Robert Whittet. Fully illustrated and very complete. Cloth. 1 00 
 
 No. 55. INSTANTANEOUS PHOTOGRAPHY. 
 
 By Captain Abney, c.b., r.e., d.c.l., f.r.s. Paper covers 75 
 
 No. 56. PHOTOGRAPHIC AMUSEMENTS. (Second Edition.) 
 
 By Walter E. Woodbury, Editor of “ The Photographic Times.” Over 
 100 illustrations. Paper covers. $1.00. Cloth 1 50 
 
 No. 57. THE AMERICAN ANNUAL OF PHOTOGRAPHY AND 
 PHOTOGRAPHIC TIMES ALMANAC FOR 1897. 
 
 With 250 illustrations. Edited by Walter E. Woodbury. Paper 75 
 Cloth 1 25 
 
 For sale by all dealers in Photographic goods, booksellers, and sent, post-paid, on 
 receipt of price, by the publishers, 
 
 The Scovill & Adams Company of N. Y., 
 
 Send for Book Catalogue. 60 & 62 East nth Street, NEW YORK CITY. 
 
A Selected List of Books 
 
 From the Scovill & Adams Co ’s Book Catalogue. 
 
 Amateur Photography. Copy? er 
 
 A Practical Guide for the Beginner. By W. I. Lincoln Adams. Illustrated. Paper covers, 50c. S 
 cloth bound qq 
 
 Lantern Slides and How to Make Them* 
 
 By A. R. Dresser. A new book, very complete and practical 25 
 
 Photography at Night. 
 
 By P. C. Duchochois. Illustrated. 108 pp. Paper covers 100 
 
 The Knack. 
 
 Written expressly to help the beginner in perplexity, reduced to 26 
 
 Photographic Lenses ; Their Choice and Use. 
 
 By J. H. Dallmeyer. A special edition, edited for American photographers. In paper covers 25 
 
 The Chemistry of Photography. 
 
 By Prof. Raphael Meldola 2 00 
 
 The Photographic Image. 
 
 By P. C. Duchochois. A Theoretical and Practical Treatise on Development. Paper covers.. . 1 50 
 Cloth bcund . 2 00 
 
 The Ferrotyper’s Guide. 
 
 For the ferrotyper, this is the only standard work. Seventeenth Edition 75 
 
 The Photographic Studios of Europe. 
 
 By H. Baden Pritchard, F.C.S. Cloth bound, $1.00; paper covers 50 
 
 History and Hand-Book of Photography. 
 
 Vvith seventy illustrations. Cloth bound, reduced to 60 
 
 Crayon Portraiture. 
 
 Complete instructions for making Crayon Portraits on Crayon Paper and on Platinum, Silver and 
 Bromide Enlargements ; also directions for the use of Transparent Liquid Water Colors, and for 
 making French Crystals. By J. A. Barhydt. A new edition. Paper covers, 50c. ; cloth bound 1 00 
 
 Art Recreations. 
 
 Ladies’ popular guide in home decorative work, with a chapter on photography. Edited by Marion 
 Kemble 1 00 
 
 The Photographer’s Book of Practical Formulas. 
 
 Compiled by Dr. W. D. Holmes, Ph.B., and E. P. Griswold. Paper covers, reduced from 75c. to 
 30c. ; cloth bound, reduced from $1.50 to 60 
 
 American Hand-Book of the Daguerrotype. 
 
 By S. D. Humphrey. (Fifth edition.) This book contains the various processes employed in taking 
 heliographic impressions 25 
 
 Sunlight and Shadow. 
 
 A Book for Photographers. Amateur and Professional. By W. I. Lincoln Adams. Beautifully Illus- 
 trated. Handsomely bound. 140 pages. In a box 2 50 
 
LANTERN-SLIDES 
 
 BY 
 
 Photographic Methods. 
 
 BY 
 
 ANDREW PRINGLE, F.R.M.S., 
 
 Ex- President Photographic Convention of the United Kingdom. 
 Author of “ Practical Photo- Micrography , ’ ’ ‘‘ The Optical 
 Lantern f and J oint-author of “ Processes 
 of Pure Photography etc. 
 
 NEW YORK: 
 
 THE SCOVILL & ADAMS COMPANY OF NEW YORK, 
 60 and 62 EAST ELEVENTH STREET. 
 
Copyright, 1897, 
 
 The Scovill & Adams Company of New York. 
 
CONTENTS 
 
 Page 
 
 CHAPTER I. 
 
 Introductory Remarks, 5 
 
 CHAPTER II. 
 
 Description of a Good Slide, 7 
 
 CHAPTER III. 
 
 Characteristics of Various Photographic Processes, 11 
 
 CHAPTER IV. 
 
 Apparatus, - 14 
 
 CHAPTER V. 
 
 The Wet Collodion Process, - - 21 
 
 CHAPTER VI. 
 
 Dry Collodion Processes, - - - 30 
 
 CHAPTER VII 
 
 Gelatine Bromide Emulsion, 39 
 
 CHAPTER VIII. 
 
 Gelatine Bromide Emulsion, Continued , 45 
 
 CHAPTER IX. 
 
 Gelatine Chloride Emulsion, 54 
 
 CHAPTER X. 
 
 Henderson’s “Argentic Stain.” “ Transferotype ” (Eastman.) 
 
 Collodio-Chloride, - 57 
 
 CHAPTER XI. 
 
 Coloring Lantern Slides, - 60 
 
 CHAPTER XII. 
 
 Masks. Mounting, - -- -- -- -- -64 
 
 CHAPTER XIII. 
 
 Reduction by Artificial Light. Combination Printing, - 66 
 
 Tables of Reduction and Enlargement, 69 
 

 
 
 
 
Lantern^ Slides 
 
 BY PHOTOGRAPHIC METHODS. 
 
 CHAPTER I. 
 
 Introductory Remarks. 
 
 Lantern-slide making is at present almost wholly confined 
 to amateurs in photography and to a few firms who turn out 
 commercially enormous numbers of slides, mostly in “ sets.” So 
 far as we know these professional slide-producers use either 
 photo-mechanical processes or the wet collodion process, while 
 the amateur as a rule uses one or other of the gelatine pro- 
 cesses, as gelatine chloride or gelatine bromide. The latter pro- 
 cess is probably more affected by the amateur than the former, 
 because very frequently the slides have to be made by “ reduc- 
 tion in the camera,” and the chloride process is too slow for 
 that system in most cases. 
 
 If we had to name the process nearest to what we consider 
 the beau ideal of a process for lantern-slide making we should 
 probably name without hesitation one of the mechanical pro- 
 cesses, Woodburytype for example. The finest slides we have 
 ever seen have been produced by that process, and it would 
 certainly tend to make this book more nearly a complete 
 
6 
 
 LANTERN-SLIDES BY PHOTOGRAPHIC METHODS. 
 
 treatise on our subject were we to give minute and practical 
 instructions for these processes. But we know that long and 
 special training is required in order to obtain mastery over 
 these processes, and much machinery and time are required ; 
 lastly we cannot give instructions from our own personal 
 experiment, so that it is held preferable to omit rather than to 
 trifle with the subject. But any one wishing to form an 
 estimate of what a slide should be, will do well to procure and 
 study a few mechanically-produced slides, say in Woodbury- 
 type. 
 
 There is, or was once, another process held in very high 
 estimation by cognoscenti in slide matters, the Albumen pro- 
 cess. This process we have worked with a fair amount of suc- 
 cess, but we found the trouble, time, and uncertainty involved 
 so great, that we could not occupy space in this brochure with 
 a full description of this process. We omit it all the less 
 reluctantly from the fact that we never did hold quite such a 
 high opinion of the results on albumen as some others did, and 
 we believe that if the peculiarities of the albumen process — 
 peculiarities chiefly of color or tone — are desired, they can be 
 obtained by more than one process given in this book. But 
 again we say that a good subject for study and imitation is an 
 albumen slide of the best quality, such as some made by 
 MM. Ferrier of Paris. 
 
 No good purpose is ever served by superficial description of 
 any process intended to yield practical results ; we shall there- 
 fore describe minutely a few processes only, rather than skim 
 over many processes. W e have allowed no space in this book 
 for guess work or speculation. 
 
CHAPTER II. 
 
 Description of a (Good Slide. 
 
 Our first and natural consideration is : what are the quali- 
 ties of a perfect lantern slide ? 
 
 To begin with we have to realize the nature and purpose of 
 a slide. A slide is a ‘positive’ image, the highest lights 
 represented on the screen by the illumination of the radiant 
 only, on the slide itself by clear glass. The details are repre- 
 sented on the slide, so far as we are concerned, by metallic 
 silver reduced by light action and chemical agency combined, 
 from silver salts, and the argentic deposit is practically opaque. 
 If we have masses of such metallic deposit on our slide we shall 
 certainly have masses of objectionable darkness on our screen 
 unless we take every precaution to deposit or reduce our sil- 
 ver in the finest possible state ; in other words our image 
 should as nearly as possible be of the nature of a stain rather 
 than of a stratum of pigment. Further : however great be the 
 brilliance of the radiant in our lantern, and however much our 
 optical system may tend to make the most of our radiant’s 
 brilliance, there must be a serious loss of light inseparable 
 from spreading an area of brilliance 3 inches in diameter over 
 an area of (say) 15 feet. When we look at an image in silver 
 or in platinum on a paper print, the opacity of the metal form- 
 ing the image has but little comparative effect on the brilliance 
 of the picture to our eyes, but when we come to look through, 
 and still more when we come to project light through and 
 greatly enlarge, our image, the opacity of the image-forming 
 substance makes a vast difference to the brilliance affecting 
 our eyes. Moreover we have to take other matters into 
 account; the almost inevitable absorbtion of light by the 
 
8 
 
 LANTERN-SLIDES BY PHOTOGRAPHIC METHODS. 
 
 screen, and the distance we require to go from the screen, and 
 so on. So that while gradation is just as essential to a slide 
 as to a paper print, the scale of light requires in a slide to be 
 higher than in a print. For a complete rendering of the scale 
 of light of Nature photography is utterly inefficient ; we ven- 
 ture to put it thus : that while in paper prints we may endeavor 
 to extend our gamut of shadows even at the risk of loss in our 
 gamut of lights, in a slide we must, perforce, keep our light 
 scale up even if we shorten our shadow region. But the best 
 slide and the best print are those wherein we have the longest 
 and the most complete scale. If in our slide we raise our 
 lights at the expense of oar shadows we have the “midsummer 
 snow-scenes” so offensive ; if we give undue prominence of 
 gradation to our shadow end we run great risk of having no 
 real high-lights at all. We see it asserted in a book professing 
 to teach art to photographers that a lantern slide must be out- 
 side the domain of art. The writer of this book says nothing 
 whatever in defence of this position of his, he bases it simply 
 on his authority, which to many minds will not be enough to 
 condemn slide making. As a matter of fact an image pro- 
 jected on a screen through a slide may be just as good or as 
 bad from an artistic point of view as a paper print. Practically 
 such an image is a print on paper, cloth, or in fresco , but it 
 is large and is not persistent. That the ordinary run of slide 
 images are incorrect in “values,” wanting gradation, false in 
 “tonality” — whatever that may be — is possible, but that these 
 defects are inherent in and inseparable from slides is a ridicu- 
 ulous and false assumption. 
 
 A slide then must have a high scale of light and full grada- 
 tion from its highest light to its deepest shadow. A large 
 mass of highest light is just as mischievous in a slide as in a 
 print, absolute opacity is just as much out of place in a slide 
 image as on a paper print image, and on account of the sub- 
 stantial nature of the slide image there is greater danger of 
 dense opacity in a slide than in a print, for the print is always 
 illuminated to our eyes by more or less reflected light. If high 
 lights preponderate in our slide the image will be of the brilliant 
 
LANTERN-SLIDES BA PHOTOGRAPHIC METHODS. 
 
 9 
 
 type ; if shadows preponderate, we shall have a subdued 
 slide ; but the gradation must be in both. A very common 
 fault indeed in slide-making is to produce a slide of an Interior 
 on a scale of light precisely coincident with the scale of an 
 open landscape ; this must be wrong, yet many slide-makers 
 congratulate themselves on such achievements which are not 
 
 O 
 
 only abominable but easy. Probably photographers are encour- 
 aged in this vandalism by the approbation of an unthinking 
 and uneducated public which applauds a ‘clear’ slide whatever 
 its other qualities may be,' but it is time that we photographers 
 should correct this. 
 
 When half-tone is in abnormal preponderance we have 
 either a “ washed-out ” image, or in aggravated cases a scale of 
 light so low as to amount to “ fog.” This is the converse fault 
 to “summer snow,” and equally baneful; it is perhaps the 
 commonest fault with beginners, and arises in nearly all cases 
 from faulty technique, or a bad negative. 
 
 The next attribute of a slide is that of color or “ tone,” or 
 as it is sometimes called “ medium.” The color of image most 
 frequently seen is a sort of cold slaty blue, It is the tone most 
 easily produced, and most objectionable if we except the dirty 
 “ bottle-green,” which luckily is not so common as it used to 
 be when plate-makers and plate-users were less skillful. This 
 slate color is seen in many amateurs’ iron-developed slides, and 
 in numbers of commercial slides where the platinum-toning 
 process has been underdone, or done on unsuitable positives. 
 Far preferable to this is a good warm blue-black, such as is 
 produced by the wet process, used properly, or by gelatine 
 processes under the best conditions of exposure and iron- 
 development, or quinol-development. But we yearn after 
 warm tones, such as can be produced easily with dry collodion, 
 with gelatine chloride, and with “Argentic Stain,” (see p. 57) 
 and less easily with gelatine bromide. We believe not only 
 that the warm tones are required for perfect slides, but that 
 the photographic world is entirely of our opinion ; the public 
 will soon follow. The albumen slides, so much admired, are 
 of warm tone, the mechanical slides are still warmer and some 
 
10 
 
 LANTERN-SLIDES BY PHOTOGRAPHIC METHODS. 
 
 of our most applauded slide-makers affect warmth and eschew 
 blues. We are referring wholly to pictorial subjects at present ; 
 slides purely scientific, as astronomical, microscopic, and the 
 like, are probably better rendered in cold — but not blue — 
 tones. We shall lay down, then, a warm tone as essential to a 
 perfect slide ; failing tints tending to red, we must content our- 
 selves with a thorough good engraving-black, such as one 
 illustrious amateur knows how to produce, but very few other 
 workers in this field. 
 
 To sum up. A slide to be perfect must have : (1) A high 
 
 scale of lighting. (2) A continuous scale of gradation. (3) 
 A pleasing tone. To put it otherwise. A slide must have : 
 (1) Clear highest lights. (2) Secondary lights well furnished 
 with detail. (3) Middle tones. (4) Transparent shadow 
 details. (5) A good general color of image. 
 
 So much for the photographic qualities of a slide ; we have 
 others to consider. The size of a slide plate is three and one- 
 quarter inches square, there is no reason for changing this size, 
 or for adopting any other. But the frame of our picture — 
 the “mask,” technically — requires consideration. Why we 
 should adopt for slides shapes and proportions practically 
 unknown in any other branch of graphic art is a mystery, and 
 the sooner we alter this practice of circular and “square- 
 cushion ” masks the better. (See remarks in Chapter XII.) 
 
CHAPTER III. 
 
 Characteristics of Various Photographic Processes. 
 
 There is a slight risk of misconception attached to this 
 chapter, and it will be well to point out where the risk lies. 
 We propose to point out what may be taken as the salient 
 features of each process for good or for bad, but the reader is 
 not intended to understand that an observed characteristic or 
 tendency is necessarily the character or result of any process. 
 Any of the processes may, under certain conditions, show all 
 the characteristics and results, good, bad and indifferent, 
 mentioned by us. 
 
 The quality of clearness in the highest lights is certainly 
 most easily obtained by the collodion processes ; these are 
 followed more or less closely in order by the gelatine-chloride 
 process, the gelatine-bromide process standing last in this 
 respect. 
 
 The quality of opacity in juxtaposition with absolute 
 clearness , which is so valuable in such slides as are copies of 
 engravings, is most easily obtained by collodion with or 
 without intensification, by gelatine-chloride, and then by 
 gelatine-bromide used in a special manner. 
 
 A long scale of gradation is a branch of excellence wherein 
 gelatine-bromide stands first, the other processes we can not 
 place in any order of merit, except that w^e are inclined to 
 place w r et collodion last. The qualities of half-tone trans- 
 parence of shadoio may be taken as synonymous or equivalent, 
 and may follow the same order, but of all the transparent 
 shadows we have ever seen produced by pure photography, none 
 could match with those produced by Mr. A. L. Henderson’s 
 “ argentic stain,” which we shall certainly mention later. 
 
12 
 
 LANTERN-SLIDES BY PHOTOGRAPHIC METHODS. 
 
 Warmth of tone may, to a certain extent, be achieved by 
 any of our processes ; but warmth combined with excellence 
 in other respects is certainly the province of dry collodion. 
 With gelatine organo-chloride plates we can with ease produce 
 a very long range of colors from scarlet to the coldest blue, but 
 there is a something lacking in the other qualities of plates 
 treated so as to give the warm tones. When first Mr. Cowan 
 showed us his grand results in this line we expected that herein 
 lay the future of slide-production, but somehow the slides did 
 not on the screen come up to our, and we presume to public, 
 expectation, for very few slides of this kind are ever seen, 
 though to our knowledge they are not difficult to produce. 
 Wet collodion slides may be, and sometimes are, “toned” to 
 really warm colors, but a suspicion as to their permanency is 
 afloat, and justly or unjustly, the dog has acquired a bad name. 
 Under the head of gelatine-bromide, careful directions shall be 
 given, the result of much experiment, for the production of 
 warm tones; but it should be clearly understood that if 
 warmth were our prime and only consideration we should use 
 dry collodion. 
 
 Next, as to our purpose and our conveniences. If our 
 purpose is simply to make lantern-slides, as good, as rapidly, 
 and as cheaply as possible, the plain course is to take quarter- 
 plate negatives, and make contact-slides on gelatine-chloride, or 
 on collodio-bromide. 
 
 So, too, if we have at command only limited time, specially 
 if the time be limited to evening, we are almost bound to 
 make our slides by contact, and so we should use gelatine- 
 chloride or collodio-bromide. But if we have a stock of 
 large negatives, or if we wish to make large negatives and from 
 them slides by reduction, these two processes are put out of the 
 field by the more rapid gelatine bromide or wet collodion, and 
 in fact the exposure tor reduction on wet collodion by artificial 
 light may almost be put aside when we consider that we have 
 gelatine-bromide more rapid, especially in ordinary artificial 
 light, and better in certain important qualities already cited. 
 But if daylight is at our disposal, and scientific slides our 
 
LANTERN-SLIDES BY PHOTOGRAPHIC METHODS. 
 
 13 
 
 object, the wet collodion process has claims not lightly to be 
 set aside. 
 
 We have next to consider what may fairly be called the best 
 all-round process. The author ventures to pronounce in favor 
 of gelatine-bromide ; it is rapid, but not too rapid for contact 
 work ; properly used it yields highest lights practically unim- 
 peachable, it is remarkable for gradation, and it will yield 
 either a good cold tone or under the best conditions a very fine 
 warm tone. And the writer will further venture to recom- 
 mend those who have but limited time, limited purse, and 
 limited intentions, to work at the gelatine-bromide process till 
 perfection is attained, as it almost certainly will by practice 
 and care be attained. Those, on the other hand, who have 
 opportunity and desire for a course of most interesting experi- 
 ments, and a succession of most beautiful results, are advised 
 to follow the matter of this little book not only with their 
 eyes and minds, but with their hands. 
 
CHAPTER IV. 
 
 Apparatus — Contact-Printing. Reduction. 
 
 We require for contact-printing an ordinary printing-frame, 
 an article well known to every photographer. If we are going 
 to make a contact slide from part of a quarter-plate negative, 
 we should use a quarter-plate frame with ledges about one- 
 eighth of an inch wide upon which the negative may rest. 
 These ledges will act as masks for two sides, or possibly three, 
 of the slide-plate. Sometimes, if the margins of the slide- 
 plate are not protected from the light passing through the 
 negative, a certain amount of blurring will be found at the 
 edge of the slide, this area of blur may or may not be hidden 
 by the mask used in mounting the slide. Anyhow it should 
 be avoided. Some persons place between the negative and 
 the slide-plate in the frame a mask with a suitable aperture, 
 and if the mask paper be very thin and of a non-actinic color 
 the result is perfect, especially if strong pressure be brought 
 to bear on the back. Sharpness must not be endangered 
 in a lantern slide, for when enlarged on a screen the image is 
 not likely to offend the most naturalistic eye by over- sharpness. 
 If the negative and printing frame are lantern-size there is no 
 difficulty. As a rule it will be found incorrect to make a con- 
 tact-slide of any portion out of the middle of a much larger 
 negative, the image on the screen always looks “ uncomfort- 
 able.” 
 
 A standard light is a matter of importance, especially to the 
 beginner. The following devices have proved satisfactory in 
 our hands : A “ Regulator gas burner.” A government 
 standard candle allowed to burn for at least three minutes before 
 exposure is made. A certain oil lamp having above its flame 
 an attached arm up to which the flame is always raised. A 
 
L AK TERN- SLIDES BY PHOTOGRAPHIC METHODS. 
 
 15 
 
 certain length of a certain make of magnesium wire or ribbon. 
 This wire or ribbon if kept for some time ceases to be a stand- 
 ard on account of the action of the air upon it. This may be 
 rectified practically by pulling the ribbon or wire several 
 times between the folds of a piece of sand or emery paper 
 held between finger and thumb. 
 
 Equally important to a standard light is a standard distance 
 from radiant to receiving surface. Looseness in the matter of 
 distance may lead to serious errors. The so-often quoted law 
 must be kept in mind : the intensity of light varies inversely as 
 the square of the distance from radiant to recipient, provided 
 the rays be not interfered with in transit, as, for instance, by a 
 paralleliser or condenser. Thus if the proper exposure be ten 
 seconds when the slide plate is held twelve inches from the 
 radiant, the corresponding exposure at eighteen inches will be : 
 
 12 3 : 18 s :: 10 : 23 seconds approximately. Again suppose 
 that we have a fixed exposure of ten seconds at eighteen 
 inches, but by mistake increase the distance to twenty inches 
 we make an error in exposure of nineteen per cent, of the 
 proper exposure ; or if x be 1 00 seconds at eighteen inches, 
 
 124 seconds (nearly) will be required to produce the same effect 
 at twenty inches. Our habit, therefore, ought to be to place 
 the radiant at a certain marked spot, and to have marked on the 
 table a scale of inches, or of short lengths, such as three inches, 
 from, say, nine inches to thirty inches. A piece of cord wdth 
 knots at various distances may be found equally useful ; and 
 when time is an object, or the cost of magnesium ribbon a 
 consideration, circles may be drawn with radii from four and 
 one-half to fifteen inches, a small spirit lamp being placed over 
 the centre of these concentric circles and the length of magne- 
 sium being ignited and held at the spirit lamp. By this 
 method a number of plates can be exposed at equal or unequal 
 distances simultaneously. The ribbon or wire must of course 
 be held in a pair of pincers or forceps. 
 
 u N on-actinic ” or “ dark-room ” lanterns are often made with 
 a door or windows which can be opened at will so that the 
 light inside may be used as radiant for giving the exposure. 
 
16 
 
 LANTERN-SLIDES BY PHOTOGRAPHIC METHODS. 
 
 Reduction in the Camera . If our negative is larger, or the 
 part of it we wish to reproduce is larger than a slide plate, we 
 mnst u reduce ” the size to the required dimensions ; in fact, we 
 mnst make a small positive photograph of our negative. The 
 mechanics of this operation are almost as simple as those for 
 contact-printing. The requirements are : Even illumination 
 
 of the negative; means for holding the negative and slide 
 plate parallel to each other ; a lens to effect the reduction ; a 
 light-tight box to hold the sensitive plate so that no light-rays 
 shall reach the plate except such as pass through the negative 
 and the lens ; “ motions,” whereby the distances from negative 
 to lens and from lens to sensitive plate can be altered ; and a 
 certain amount of traverse, horizontal and vertical, whereby 
 the lens can be placed opposite to various parts of the surface 
 of the negative. If we intend to use one size only of negative, 
 and to reduce the whole of its image each time, our apparatus 
 may be even simpler, for we shall then require no “ traverse” 
 and very little focusing motion, and no alteration of distance, 
 once fixed, between negative and lens. 
 
 The simplest arrangement we ever saw consisted in hanging 
 or placing on a ledge in a window having no trees nor other 
 objects within many yards outside, the negative to be copied. 
 A camera on a studio stand was then wheeled up, squared and 
 focused, and a wet plate exposed in the camera. The results, 
 so far as the apparatus was concerned, left nothing to be 
 desired ; but if one has many different size negatives to reduce, 
 or wishes to reduce now one part now another, there must be 
 a little trouble about the centering and squaring so often. 
 
 Nothing can well be simpler than the following, Fig. 1 : 
 
 A B 
 
 Fig. 1. 
 
 A is a framework carrying the negative, B a little camera 
 of the plainest construction, fitted with a rack and pinion 
 
LANTERN-SLIDES BY PHOTOGRAPHIC METHODS. IT 
 
 focusing arrangement and having a front carrying a lens and 
 traversing in both directions. If we intend always to include 
 in our slide the whole of the subject shown on the negatives 
 there is no need for traverses ; and the traverse can be effected 
 equally well on the base board C D, or on the block on which 
 the camera is raised, or the frame carrying the negative may 
 traverse, it is a matter of choice if it is necessary at all. The 
 negative frame may advance and recede along C D in ayy 
 convenient way, between runners or along a longitudinal slot 
 in C D, or the block on which B rests may move in like man- 
 ner. The negative in A and the plate in B must always be 
 parallel. A should be so arranged that whatever size of nega- 
 tive be used its centre should always be in the optical axis of 
 the lens in B at the normal position; for this the best system 
 is to make A consist of “ nested carriers.’ The amount of 
 reduction is regulated by the distance from A to B, the focus 
 of the lens is adjusted by the focusing arrangement of B. 
 
 If this entire system can be pointed at a clear sky the light- 
 ing of A will be even, but if clouds, or trees or houses are 
 behind A the lighting should be modified either by an angled 
 reflector, which must be larger than the negative, or by a 
 sheet of ground glass or tissue paper an inch or two behind, 
 and parallel to, and as large as, the negative. The reflector, 
 if one is used, should be white but not glossy ; nothing is 
 better than a sheet of fine white filter or blotting paper. 
 Mirrors, opals and such shiny surfaces are inferior to matt 
 surfaces theoretically and practically. The best angle for the 
 re&ector will be found by experiment, and the more it is 
 angled and the further it is from the negative the larger it 
 will require to be. The ground glass or tissue paper arrange- 
 ment may be as fine in “ grain” as is consistent with diffusion 
 of the light ; if there are dark objects anywhere close behind 
 the negative, as trees or houses, the effect will soon be noticed, 
 if not in the camera certainly on the slide. The entire system 
 of Fig. 1 should always point to the North if such an aspect 
 is available, that is to say, the negative should be North of 
 the camera; if the sun shines directly or by reflection from a 
 mirror on the negative, mischief may be expected. 
 
18 
 
 LANTERN- SLIDES BY PHOTOGRAPHIC METHODS. 
 
 It is not perhaps essential but it is certainly advisable to 
 prevent light from intervening between negative and lens, 
 except such light as has passed through the former. Between 
 A. and B., then, an opaque cloth may stretch, supported if 
 necessary on standards. Or a box with the ends knocked out 
 may suffice. 
 
 A handy carpenter can make an arrangement such as Fig. 1 
 in an hour, if paid by the piece, and provided with the camera 
 and carriers. 
 
 Fig. 2 was made by the writer in 10 minutes, or thereabout, 
 he uses no other arrangement and has not a fault to find 
 with it. 
 
 The arrangement, as will be seen at once, consists of two 
 cameras stuck face to face ; the cut (Fig. 2) shows all the 
 
LANTERN SLIDES BY PHOTOGRAPHIC METHODS. 
 
 19 
 
 ‘making’ needed on the part of the writer. A piece of wood, 
 chosen grooved for convenience of making sliding runners, was 
 screwed to the front of a little quarter plate camera, useless 
 for outdoor work from age and infirmity. An oblong hole 
 was made in the middle of the piece of wood ; the screwed-on 
 front was run into the runners in the front of the large camera 
 which also was superannuated, and superseded on account of 
 its weight. The lens was screwed into its flange in the small 
 camera through the hack of the large camera, and the appar- 
 atus was complete. A wet-plate slide opened back and front 
 holds the negative, carriers or ‘kits’ hold different sized nega- 
 tives ; distance from negative to lens is regulated by the rack 
 and pinion of the large camera, focussing is adjusted by the 
 small camera, traverse in both directions is attained by the 
 front of the large camera or in extraordinary cases by pulling 
 out the slide carrying the negative. Thus the apparatus is 
 complete and universal. Every one has the camera in which 
 he took the original negatives ; this camera is in no way hurt 
 or altered by the attachment of the little camera ; and the lat- 
 ter requires absolutely no motion except the invariable one for 
 focusing, so that a mere toy camera is good enough. Ground 
 glass, or angled reflector is as before. 
 
 The arrangements given above are not makeshifts, we never 
 would use a makeshift, still less recommend one. We do not 
 believe that a better arrangement could be devised or made at 
 any expense whatever, and the reader will own our apparatus 
 is simple enough. 
 
 In most cases it is well, in many it is necessary, to cant the 
 whole apparatus more or less ; this is easily managed, and 
 requires no instruction. In Fig. 2 is shown the head of a 
 cheap studio stand. 
 
 The lens used should be rectilinear, and should be of such 
 focal length and construction as to cover at a reasonable 
 aperture the whole of a 3^ inch plate sharply. There is no 
 need of a lens of more than 4 inches solar focal length ; the 
 one we invariably use is a “ rectilinear stereo,” of under 4 
 inches focal length, made by Dallmeyer, and used almost 
 always at yl. 
 
20 
 
 LANTERN-SLIDES BY PHOTOGRAPHIC METHODS. 
 
 Some kind of ocular is required to adjust tlie focus on the 
 ground-glass of the little camera, for the details are often too 
 small for the eye to appreciate critically in the very subdued 
 light forming the image on the screen. The article known as 
 a Ramsden eye-piece, magnifying about three times, is what we 
 use. This glass, and all used in a similar way, must itself be 
 focused on the inner side of the focusing screen ; the metal 
 cell carrying the glass being in contact with the outer side of 
 the focusing screen. The “ grain ” of the ground-glass is a 
 very difficult surface on which to set the Ramsden ; but if a 
 fly’s wing or some such object be temporarily fixed to the front 
 of the ground-glass, and viewed from the opposite side, the 
 ocular can be easily and accurately set to focus. It will be 
 found very convenient to put in the centre of the ground-side 
 of the focusing screen a pafcli of oil, or to cement to it a 
 round microscopic 66 cover-glass ’* with Canada balsam. This 
 clear spot may be about half an inch to an inch in diameter. 
 
CHAPTER Y. 
 
 The Wet Collodion Process. 
 
 Full and minute instructions for every operation connected 
 with the process which for years occupied the attention of every 
 photographer in the world could not very well be given in so 
 small a space as is at our command. For the general features 
 of the process and the general method of manipulation the 
 reader may refer to any book with any pretence of complete- 
 ness in the treatment of photographic processes. In particular, 
 a sufficiently full and careful digest of the operations will be 
 found in “ Processes of Pure Photography ” in the production 
 of which the present author had a hand, in collaboration with 
 Prof. Burton, C. E. (Hew York, The Scovill & Adams Co., 
 1889.) What we propose to do here is to give a correct but 
 cursory resume of the process, emphasizing those points 
 demanding or deserving special notice from those using the 
 process for slide-making. 
 
 We have already pointed out the good and the doubtful 
 qualities of this process for our purpose, we now wish to show 
 wherein lie the special dangers, and the means of attaining the 
 special excellencies. In general the dangers are those arising 
 from atmospheric impurities and chemical carelessness. The 
 plate is wet or damp from beginning to end, and is not like a 
 dry plate submerged in a liquid all the time while the critical 
 chemical operations are going on, for the wet plate is taken 
 out of the bath, put into a slide, and carried about rooms in a 
 state most apt to catch dust ; and moreover the silver nitrate, 
 both in the bath and on the plate, is highly sensitive to 
 organic contamination. The greatest care is therefore nec- 
 essary to avoid dust at every stage, and to banish from the 
 
22 
 
 LANTERN-SLIDES BY PHOTOGRAPHIC METHODS 
 
 vicinity every trace of suspended organic matter. The very 
 cleaning of the glass plate is a function the gravity of which 
 the modern dry plate man can barely conceive. Organic mat- 
 ter produces veil or fog and so destroys the strongest point in 
 favor of this process, while dust adhering to the film is fatal to 
 the mechanical perfection of the result. 
 
 The glass used should be thin, flawless, and flat, and the 
 size should be larger each way than the slide is to he. A suita- 
 ble size may he 4 inches square, or 4 will probably be more 
 convenient as one dimension of a quarter-plate. A square 
 quarter-plate camera will then he required, or at least a square 
 dark slide. The necessary image will he only about 3 inches in 
 its longest dimension. If the glass is new, a good rubbing, 
 first with alcohol and ammonia equal parts with a little tripoli 
 added, will remove from the surface dirt of a greasy nature. 
 After this it requires a strenuous polishing with a perfectly 
 clean chamois leather, not washed in soda. If the plate has been 
 used previously it should be soaked for an hour in nitric acid 
 and water equal parts, then well washed under a tap, then 
 cleaned and polished as before. The collodion should not be 
 quite freshly iodised, still less should it be very old, and the 
 proportion of bromide should be kept down, while iodide may 
 be in excess of the usual proportion for landscape or portrait- 
 ure. The plate held on a scrupulously clean holder, rather 
 than in or on the fingers, is to be coated with collodion in the 
 time-honored fashion, steadily, evenly, and entirely sheltered 
 from dust. The surplus collodion should not be returned to 
 the bottle whence it came, but to a second ; and certainly there 
 must be no grinding of the plate on the mouth of the bottle. 
 A proper collodion pourer should be used, ordinary bottles 
 lead to frequent mischief. The corner at which the surplus 
 runs off is to be kept downwards, but the plate while the collo- 
 dion is dripping must be very steadily rocked sidewise to 
 ensure even coating and absence of ridges. When the drip- 
 corner is “tacky” and shows an impression of the finger-skin 
 that may be made to touch it, the plate is ready to be put into 
 the silver bath. The collodion may take from 20 to 50 or 60 
 
LANTERN-SLIDES BY PHOTOGRAPHIC METHODS. 23 
 
 seconds to set as above, according to temperatnre. No part 
 of the film must be dry when the plate is immersed in the sil- 
 ver bath. 
 
 The “ silver ” or “ sensitizing ” bath is very easy to make, 
 but not so easy to keep in order ; so it is well to make two 
 separate quantities of it at first, and to use one portion while 
 the other is allowed to rest or is under repair, for the bath 
 needs rest and repair occasionally. Distilled water (not con- 
 densed, however, from greasy engine valves), should be used, 
 or rain water caught directly in a clean porcelain vessel, or 
 ordinary pure water treated with a crystal or two of silver nit- 
 rate and kept for some days in a bright light. Rain water 
 should be treated in the same way. A good strength for the 
 bath will be : thirty-five grains of re-crystallized silver nitrate 
 to water one ounce. For lantern slides we recommend a “dip- 
 ping bath ” in preference to a flat dish for sensitizing the 
 plates, as the former is likely to secure greater immunity from 
 dust on the plate. (See “ Processes.”) The dipping bath will 
 require a larger original bulk of silver solution, but the larger 
 quantity will keep longer in working order. The bath must 
 be slightly iodized before the serious work begins ; to do this, 
 coat a plate with iodized collodion and leave it in the bath 
 solution for some hours, or add a crystal of potassium iodide 
 directly to the bath. 
 
 The plate coated with collodion is, when “ set,” immersed 
 steadily and without stoppage or hesitation in the bath, care 
 being taken that the fingers do not touch the solution, but only 
 the dipper or a silver hook made for the purpose ; and after 
 resting in the solution for one minute it is raised out of the 
 solution for a couple of seconds and let down again, and it may 
 be gently shaken in the solution from time to time during its 
 sensitization The bath is of course situated in the dark-room, 
 yellow glass being a sufficient protection from actinic rays, 
 even of day fight, and the “ wet-plate dark slide ” is placed 
 ready at hand, not lying fiat, but leaning at an angle against 
 some object. A few pieces of pure filter paper should also be 
 at hand. The “ dark slide ” used for dry plates will not 
 
24 
 
 LANTERN-SLIDES BY PHOTOGRAPHIC METHODS. 
 
 answer for wet plates, in tlie latter case the plate must rest on 
 pure silver wires, or glass corners, and the slide mnst he wiped 
 out carefully after each plate has been removed from it. 
 
 After a certain time of immersion depending on the tem- 
 perature and on the nature and condition of collodion and bath, 
 but varying from three to five minutes, it will be seen on lifting 
 the plate from the bath that the greasy or streaky appearance 
 seen when the plate was lifted the first time has disappeared. 
 When this is the state of affairs the plate is fully sensitized, 
 and it will have a film opalescent and bluish or gray according 
 to the salts used in the collodion. The plate is lifted slowly 
 from the bath, allowed to rest one end for a few seconds on 
 several plies of pure filter paper, the back wiped with filter 
 paper ; and, the same edge being carefully kept downward 
 throughout, the plate is placed in the dark slide, and the door 
 of the slide shut. A piece of red blotting paper may with 
 advantage be used to back the whole plate in the slide. The 
 slide is to be carried, and laid down, always with the same 
 side downward ; the solution sure to accumulate at the lower 
 part of the plate must never be allowed to run back over 
 the film. 
 
 The silver bath must be acid in reaction, decidedly acid for 
 our special work. And to acidify it we prefer nitric to acetic 
 acid. A great excess of acidity makes the film less sensitive 
 to light, but we must have a certain amount of acidity to 
 ensure clearness. Fig. 3 shows a “ dipping bath,’’ if a flat 
 dish is to be used it should be of glass. The “ dipper ” in one 
 case and the “ hook ” in the other should be of silver. 
 
 The bath, as we have hinted, is liable to certain diseases, 
 and is sure to contract one or other in time. It may become 
 supersaturated with iodine, which will cause transparent spots, 
 called “ pinholes,” and this may be cured by dilution, filtra- 
 tion, and recuperation to original strength. Ether and alcohol 
 from the collodion will, in time, find their way to a mischiev- 
 ous extent into the bath, when the plates will be streaky and 
 unevenly sensitized ; the cure for this is to heat the solution 
 for a time to about 140 degs. Fahr. Organic matter is likely 
 
LANTERN-SLIDES BY PHOTOGRAPHIC METHODS. 
 
 25 
 
 sooner or later to contaminate the bath, and fog will mar the 
 images; to cure this, neutralize the acidity with excess of 
 sodium carbonate, place the liquid in the sun for some days, 
 filter very carefully and re-acidify with nitric acid. The bath 
 must, of course, be kept up to strength, to test which a hydro- 
 meter arranged as an u argentometer ” may be used. When 
 one bath is undergoing any of these regenerating processes, 
 the duplicate previously recommended will come into use. 
 
 The wet collodion process is practically used only for reduc- 
 tion, or at least copying processes, for it would evidently be 
 awkward to make a contact slide with a wet plate. The 
 
 Fig. 3. 
 
 exposure in the camera must be found out by experiment, but 
 copying a negative of average density, reducing to one-third 
 size, lens at daylight in autumn, fine ground glass behind 
 negative, system pointing toward sky, chemicals in good order, 
 bath fairly acid, we find an exposure of about 90 seconds is 
 required, using the iron developer given on page 27. 
 
 After exposure in the camera, the plate is to be carried, 
 with precautions as before, into the dark-room, and the devel- 
 oping solution being in a cup of suitable size and shape, as an 
 egg-cup, is u swished ” over the plate, starting at the edge 
 which was uppermost in the dark slide. This application of 
 the developer differs from that used in the negative process 
 
26 LANTERN-SLIDES BY PHOTOGRAPHIC METHODS. 
 
 in that with our process there is no harm in sending a small 
 quantity of the solution beyond the edges of the plate, for we 
 not want any great density. If, however, the plate has been 
 a long time in the dark slide, as (say) 20 minutes, it is better 
 not to throw overboard any considerable quantity of the solu- 
 tion. Care must be taken that the accumulation of silver 
 solution at the lower edge of the plate, if contaminated by the 
 wood of the dark slide, be not allowed to run back over the 
 plate so as to cause stains. 
 
 We formulate two developers, the former, No. 1, requiring, 
 perhaps, three times the exposure needed for the second, but 
 No. 1 gives the better results in our opinion, the grain of 
 image is finer, and the positive is usually easier to tone, 
 (see later.) 
 
 Pyrogallol 
 
 Acetic acid (glacial) 
 (Or, Nitric acid. . 
 
 "Water 
 
 Alcohol 
 
 No. 1. 
 
 . 2 grains 
 
 25 minims 
 
 1 minim) 
 
 1 ounce 
 
 according to requirement 
 
 The pyrogallic acid may very well be dissolved in alcohol 
 with the nitric acid added to preserve the pyro. Thus : 
 
 Pyrogallol 60 grains 
 
 Nitric acid 80 minims 
 
 Alcohol . . to li ounce 
 
 Of this solution ten minims will represent one grain of pyro, 
 with the requisite acid, and the alcohol will probably suffice 
 unless the silver bath solution be very much used. A new 
 silver bath requires practically no alcohol, but if ever the 
 developer runs in streaks over the plate alcohol should be 
 added to the developer unless indeed there is too much alcohol 
 in it already. To make up No. 1 with pyro. preserved as 
 above we take 
 
 Pyro-alcohol acid solution, 
 Water 
 
 . . 20 minims 
 to 1 ounce 
 
LANTERN-SLIDES BY PHOTOGRAPHIC METHODS. 
 
 27 
 
 No. 2. 
 
 Iron protosulphate 12 grains 
 
 Nitric acid 1 minim 
 
 Water to 1 ounce 
 
 Alcohol q. s. 
 
 The iron may be used in larger or smaller proportion, but 
 the above is a good average for temperate weather. The iron 
 solution No. 2 and the alcoholic pyro. solution of No. 1 will 
 keep a fairly long time. The iron salt must he chosen fresh, 
 i. e. a good green color, and not rusty-looking. The effect 
 of the acid is to make the developing operation slower, 
 and to prevent veil, so that much acid either in bath or 
 developer necessitates longer exposure. If the pyro. developer 
 becomes turbid on the plate it must be rejected instantly and a 
 fresh lot applied. The developing solutions are not to be 
 poured on to and off from, the plate, but kept moving steadily 
 over the film, and they must not act too long. The iron, for 
 instance, ought to do its work in twenty seconds, the pyro will 
 act more slowly. The appearance of the plate under develop- 
 ment is our best guide in the matter of exposure. If the image 
 flashes up, gray all over, we have over-exposed in the camera ; 
 if the image comes reluctantly and strong in contrast or 
 refuses to appear, or is very weak we have under-exposed. If 
 the image shows a fair amount of detail, but is thin, under- 
 exposure is the probable cause. As soon as the developer 
 seems to produce no more effect, or as soon as it shows signs of 
 becoming muddy, it must be thrown off the plate, and the 
 plate washed in water. 
 
 Re-development is often needed, and is indicated when the 
 density obtained by the first development is insufficient. 
 Re-development consists simply in a second development with 
 the help of a fresh quantity of silver nitrate to replace what 
 has been washed off. Take half an ounce of the original 
 developing solution and add to it about ten minims of the fol- 
 lowing : 
 
 Silver nitrate 48 grains 
 
 Nitric acid 1 minim 
 
 Water to 1 ounce 
 
 Use this as the developer was used, bewaring of turbid- 
 
28 
 
 LANTERN-SLIDES BY PHOTOGRAPHIC METHODS. 
 
 ity as before. If the plate has been slightly over-exposed and 
 is full of detail inclined to be gray, re-development must not 
 be practised, but rather 
 
 Intensification. After the plate is fixed and well washed 
 we can accentuate such details as are already developed, by 
 proceeding exactly as for re-development ; i.e., by taking some 
 of the developing solution and a small quantity of acid silver. 
 Precautions as before. 
 
 Fixing , or Clearing. To remove silver haloids not reduced 
 by light and development we use a solution of sodium hypo- 
 sulphite 1 part, water about 5 parts ; or, perhaps preferably, 
 potassium cyanide, 20 grains, water, 1 ounce. (The latter salt 
 is very poisonous, even by absorption, if in quantity. If by 
 chance cyanide is swallowed, a dose of the iron developer, or of 
 iron sulphate alone, taken immediately, will produce, with the 
 cyanide, an insoluble compound, and so will prevent fatalities.) 
 The action of the cyanide must be watched, the operation of 
 clearing being carried on like the other operations of this pro- 
 cess with the plate on a pneumatic holder or similar contri- 
 vance. If very strong the cyanide, especially if not quite pure, 
 will attack the liner details in the high lights ; if the process 
 be watched this can easily be prevented. Hypo has less ten- 
 dency to “ eat” but is more difficult to wash out, and before 
 intensification the fixing agent must be thoroughly washed 
 out. 
 
 If a finished plate after washing be dried before a fire it will 
 take a little more density than if dried spontaneously. 
 
 The tone of a slide produced as above will probably be 
 unsuitable for fulfillment of one of our desiderata , but a pyro- 
 developed plate will have a tone either better as it stands or 
 more amenable to toning than an iron developed slide. To 
 tone either one or other, take 
 
 Platinic chloride (PtCl 4 ) 1 grain 
 
 Nitric acid 1 minim 
 
 Water to 3 ounces 
 
 Immerse the well washed plate after fixation in this and 
 watch the progress, the color will proceed from brown onward 
 to nearly black. Palladium chloride may be used, according 
 
LANTERN-SLIDES BY PHOTOGRAPHIC METHODS. 
 
 29 
 
 to Mr. T. X. Armstrong, in the same way, but it tones more 
 slowly, and, if anything, results in a warmer brown tone. 
 Several baths of the platinum^ may be used consecutively ; this 
 is found a good and economical practice by some slide makers 
 of commerce. 
 
 Gold may also be used to tone and it yields a fine warmth, 
 notably in the hands of certain trade slide-makers. 
 
 The writer is indebted to Mr. Fred. York, perhaps the 
 largest producer of lantern-slides in the world, for the follow- 
 ing system of toning lantern-slides with sulphur. 
 
 Apply to therwashed slide a very weak solution of mercury 
 bichloride, but do not let the film bleach at all, if the film is 
 allowed to turn white there will be over-density afterwards. 
 Wash the plate and apply a solution of potassium sulphide 
 (liver of sulphur) 2 drams to water 1 pint. This will pro- 
 duce a very useful tone ; a little intensification may result, but 
 the varnish will remove the superfluous density. 
 
 Collodion plates always require to be varnished, for the film 
 is very tender and liable to scratches and other damage. The 
 varnishes used for negatives are as a rule yellow, and so not 
 suitable for slides. Yarnish perfectly white, and known as 
 u crystal varnish,” is sold, and usually good, the solvent of the 
 gum being benzole or wood naptha. In these cases the var- 
 nish is applied to the plate cold, the application being after 
 the manner of collodionizing a plate. After the varnish is 
 thoroughly dry the plate is to be cut down with a diamond to 
 3J inches square, and mounted as directed in another chapter 
 (Chap. XII). 
 
 If clear varnish is not procurable the following formula will 
 be found to answer : 
 
 Amber Varnish. 
 
 Gum amber dissolved in chloroform — or a less costly varnish due to 
 Mr. York. 
 
 Sandarac 1 ounce 
 
 Mastic ounce 
 
 Benzole 20 ounces 
 
 If the collodion is attacked by this, flood the plate with 
 albumen previously to varnishing. 
 
CHAPTEE VI. 
 
 Dry Collodion Processes. 
 
 We now come to a set of processes which for lantern-slide 
 making may in certain respects he equalled, but cannot, so far 
 as we know, be surpassed by any photographic process at 
 present in vogue. For camera-copying purposes these pro- 
 cesses with dry collodion are very slow, 'especially the bath 
 process given first, but in proportion almost direct to their 
 insensitiveness they endow us with a power of getting clear 
 slides and of modifying the tones of our slides. 
 
 No person can claim to have done his best to produce per- 
 fect slides, unless he has carefully tried the effects of each of 
 the processes of which we shall give examples. 
 
 Collodion Plates, Bathed and Dried. 
 
 After a plate, collodionized, and sensitized in a silver bath, 
 as directed in last chapter, is taken out of the bath, it may be 
 washed in distilled water, dried, and preserved for a certain 
 time, if certain steps be taken to prevent the pores of the col- 
 lodion from completely closing up, and to furnish some sub- 
 stance to absorb the halogens when exposure and development 
 take place. The substances so used are called “preserva- 
 tives” or “ organifiers ” technically. The plate after washing 
 may be immersed for two minutes in strong coffee (ground 
 coffee 2 ounces, boiling water 10 ounces), or in “fiat” beer, or 
 in a 12-grain aqueous solution of tannin, or in equal parts of 
 albumen and water. After this immersion the plates are 
 simply dried, and used when required. The collodion may be 
 any good sample, salted as in last chapter, the plates must be 
 
LANTERN-SLIDES BY PHOTOGRAPHIC METHODS. 31 
 
 left for an ample time in the sensitizing bath, perhaps twice 
 as long as for wet plate work. The developers given for col- 
 lodion emulsion will answer for these dried plates, after opera- 
 tions as for wet plate. The exposure required for plates 
 prepared as above is exceedingly protracted, in fact camera- 
 copying is well-nigh out of the question. Not less^ than 
 twenty times the exposure for wet plates will be needed for 
 these dried ones. 
 
 Collodion Emulsion “ Unwashed.” 
 
 Here, in place of forming the sensitive salts in a film 
 previously containing the haloid salts only, by immersion in a 
 silver nitrate bath, we form the sensitive salts in the collodion 
 and thereafter coat the plate. W e put silver nitrate into salted 
 collodion, whereby at once an emulsion of collodion and silver 
 salts is formed, but also there are formed as bye-products 
 certain salts, useless and hurtful, which luckily are soluble 
 in water, while the silver salts are not soluble in that 
 liquid. Moreover we require to dissolve our silver nitrate, 
 and as a considerable quantity of water would spoil our 
 collodion, and would not mix with it, we dissolve our silver in 
 a very small quantity of water, and then add alcohol to it. To 
 get rid of the soluble bye-products we wash in water either the 
 whole bulk of emulsion, (“ washed emulsion process,” page 33) or 
 each plate as it is coated ( u unwashed emulsion process.”) With 
 the latter we now deal, and our formula is based on one given 
 by Mr. W. B. Bolton some years ago. We have tried many 
 formulae, but found none more simple or efficient than this : 
 Mix 3J ounces of sulphuric ether, sp. gr. *720, with 2 ounces 
 (fluid) of alcohol sp. gr. *820, put into a stoppered bottle along 
 with 36 grains of high temperature pyroxyline, and 59 grains of 
 dry zinc bromide. The pyroxyline must be fresh ; the high tem- 
 perature samples do not keep well. The zinc bromide if found 
 damp in its bottle must be dried before it is weighed out, and 
 if the sample be not quite pure a slightly larger quantity may 
 be used. In all emulsion work accuracy of weighing and 
 measurement is essential to success. The pyroxyline will take 
 
32 LANTERN-SLIDES BY PHOTOGRAPHIC METHODS. 
 
 some time to dissolve; the bottle should be shaken once or 
 twice at first, and then allowed to stand still for a day that any 
 sediment may settle. The clear portion is to be decanted off, 
 care being taken that there are 5J ounces of the clear, for 
 which reason an extra bulk of the collodion should be made 
 at first. 
 
 Put into a test tube 
 
 Silver nitrate. . 
 
 Distilled water 
 
 Boil. 
 
 Put into another tube or flask 
 
 Alcohol '820 6 drams 
 
 Boil. 
 
 While both are boiling pour four drams of the alcohol into 
 the silver solution, keeping the rest of the alcohol till required. 
 Take the bromised collodion, five and one-quarter ounces, the 
 silver solution, and the small quantity of alcohol, into the dark 
 room, keeping the silver hot ; and then pour the silver, a few 
 drops at a time, into the bromised collodion, giving the collodion 
 bottle a violent shaking after each addition of silver. When the 
 silver tube is empty wash it out with the surplus alcohol, and 
 pour that into the collodion, shaking strongly for a couple of 
 minutes. The previously clear collodion will now be like so 
 much cream, and only requires to be set aside for twenty-four 
 hours or two days when it will after filtration through pure 
 swan’s-down calico, or medicated cotton wool, previously 
 moistened with alcohol, be ready for coating plates. 
 
 The glass plates may this time be the proper size, viz., 31- 
 inches square, and they must be cleaned as for wet collodion. 
 Or they may be albumenized, which is an operation we do not 
 recommend for bath processes. Shake up the white of an egg 
 with 40 ounces of water containing enough liquor ammonia to 
 cause the liquid to smell distinctly ; let stand for some hours, 
 then filter with great care. To albumenize a plate, clean it 
 with soda and water, wash the soda entirely off under the tap, 
 pour the albumen solution over the wet plate once, throwing 
 
 90 grains 
 45 minims 
 
LANTERN-SLIDES BY PHOTOGRAPHIC METHODS. 
 
 33 
 
 away the albumen, and again, reserving the albumen if 
 desired, but filtering into a second bottle. Let the plate dry. 
 Or the plate may be coated with a very thin solution of pure 
 india rubber (or Para gum) in pure benzole, or an “edging” J 
 of an inch wide may be put all around the plate with a camel 
 hair brush. Or after the plate is cleaned and dried, powdered 
 talc (French chalk) may be rubbed over it and then rubbed off 
 till none is visible, but this rubbing is not to be violent, nor to 
 amount to polishing. If one or other of these steps be not 
 taken the film will leave the glass during after-operations. 
 The albumen is perhaps the “prettiest” dodge, and the solution 
 improves by keeping if the ammoniacal smell be kept up. 
 
 The plate is taken on a holder and coated with the emulsion, 
 evenly and steadily, overflow being filtered through cotton 
 wool into a second bottle. When the collodion has set the 
 plate is laid in a dish of distilled water for one minute, then it 
 is washed in common water till greasiness disappears, then it is 
 immersed for one minute in coffee as on page 30, or in : 
 
 Bitter Beer — 10 ounces 
 
 Pyrogallol 10 grains 
 
 Wash the plate after the beer but not after the coffee. Put 
 aside to dry. This emulsion will keep for a long time, but 
 coated plates will not keep nearly so well. An hour before 
 coating plates the bottle of emulsion should be well shaken ; 
 
 thereafter it is to be kept steady until coating-time. With a 
 good sized bath for distilled water and one for the preservative, 
 we can easily coat and finish 3 dozen plates in an hour. 
 
 Washed Collodion Emulsion. 
 
 This process is very similar to the last up to a certain point. 
 W e form an emulsion stronger in Pyroxyline and silver salts, 
 thus : 
 
 Ether .720 3^ ounces 
 
 Alcohol .820 2 ounces 
 
 Pyroxyline 48 grains 
 
 Zinc Bromide 72 grains* 
 
 Silver Nitrate 120 grains 
 
 * See the caution regarding purity on page 31. 
 
34 LANTERN-SLIDES BY PHOTOGRAPHIC METHODS. 
 
 Emulsification is conducted as before, and the emulsion 
 ripens in from 48 to 60 hours. Then it is poured out into a 
 large flat perfectly clean glass or porcelain dish, and allowed to 
 set. As soon as a skin forms on top it is broken with a silver 
 or ivory implement, so that the solvents ' may evaporate 
 entirely. Then the mass is broken, or cut, or torn into minute 
 pieces which are put into running water for, say, 12 hours. 
 We put ours into a tea pot of earthenware, tying muslin over 
 the lid-hole, and running water in through the spout. Then 
 the pellicle is collected, squeezed strongly to remove water, 
 and kept under strong alcohol for 2 hours at least. Then it is 
 dried, and when required dissolved thus : 
 
 Pellicle 20 to 25 grains 
 
 Ether 4 drams 
 
 Alcohol 4 drams 
 
 Of course it need not be dissolved until, and except in such 
 quantity as, it is wanted. The plates are simply coated as already 
 directed on page 33, and allowed to dry, slight heat to acceler- 
 ate drying will do no harm. If the emulsion becomes after a 
 time too thick, dilute it with equal parts of ether and alcohol, 
 but it must be creamy, not milky. The emulsion is to be 
 shaken one hour before coating. 
 
 Development of All Dry Collodion Plates. 
 
 The exposure varies much with the tone aimed at and con- 
 sequently with the developer used. The bath process is very 
 slow even at its quickest, and the emulsion plates are certainly 
 three times as slow as wet collodion even at their best, unless 
 very poor tones are to result. 
 
 The idea of the developers we give is due chiefly to Mr. 
 Brooks, of Beigate, who is a most successful producer of col- 
 lodio-bromide emulsions for slides, and of slides with his pro- 
 duction. Those whose experience is limited to development 
 of wet and gelatine-bromide plates must be prepared for quite 
 novel phenomena in the development of dry collodion plates. 
 It may be taken as a general rule that wdth dry collodion we 
 
LANTERN-SLIDES BY PHOTOGRAPHIC METHODS. 
 
 35 
 
 develop all tlie detail first, and the density afterwards. This, 
 at all events,- is a description that will not lead any one far 
 astray ; if any one finds himself getting all the detail on his 
 plate without density, it is a mere matter of time to get the 
 density with collodion emulsion. If any great density is 
 acquired before all detail is up, we may be sure the plate is 
 under-exposed and useless. If the details rush up hurriedly 
 and refuse to take density, we have over-exposed and our best 
 resource is to wash, fix and intensify. 
 
 Before developing we run India rubber solution round the 
 edges, whether the plate was edged or albumenized previously 
 or not. W e may hold the plate on a holder in the hand and 
 pour the developing solution on, or we may put the plate into 
 a dish and develop as for a gelatine plate. 
 
 The longer the exposure, counteracted by a restrained devel- 
 opment, the warmer will be the tone of our slide. W e cannot 
 get a really warm tone after a sub-normal exposure ; if we use 
 a heavily restrained or a naturally weak developer our plate 
 will simply be under-exposed ; if we use a stronger developer 
 we may get a slide perfect in every respect but the tone, 
 which will be cold. If we desire, or are satisfied with cold 
 tones, we shall do better to use other processes more rapid and 
 simple. 
 
 The first step towards development is to flood the plate with 
 equal parts of methylated spirits and water, allowing the mix- 
 ture to act on the film for about thirty seconds, then pour it 
 off and wash the plate. This step is to be taken with all the 
 collodion emulsion processes we give. We have a great 
 choice of developers, each one tending to give its own 
 particular tone. Ferrous oxalate, for instance (see page 16), 
 will yield a slide quite good in quality, but probably cold blue 
 in color. 
 
 Mr. W. Brooks uses a developer which may be made as fol- 
 lows : 
 
 a. Dissolve 96 grains of pyrogallol in 1 ounce of absolute alcohol. 
 
 This will be very easily done and requires no comment. 
 
36 
 
 LANTERN-SLIDES BY PHOTOGRAPHIC METHODS. 
 
 b (1). Ammonium carbonate ( saturated solution). ...... 4 ounces 
 
 Potassium bromide 1 dram 
 
 Sodium acetate 2 drams 
 
 Water 12 ounces 
 
 To prepare the solution of ammonium carbonate properly is 
 important. The carbonate must be of the best quality and 
 fresh, the crystals clear and not amorphous ; if there is around 
 the lumps of carbonate a coating of white amorphous salt the 
 latter should be pared off with a knife, as it not only does not 
 help development but retards it. The lumps should be broken 
 into small pieces, put into a bottle with distilled water for 
 some days, the bottle getting a vigorous shaking occasionally. 
 
 This b used with a as will be directed presently, gives very 
 beautiful warm tones, as fine as any tones that can be produced 
 by any purely photographic process. But by wholly or partly 
 replacing the ammonium carbonate by sodium or potassium car- 
 bonate we may be enabled to reduce our exposure, though at the 
 expense of a certain amount of warmth of tone. An alkaline 
 solution (b\ of which we are very fond, gives a fine chestnut 
 
 tone : 
 
 <5 (2). Potassium carbonate 800 grains 
 
 Potassium bi-carbonate 150 grains 
 
 Potassium bromide 60 grains 
 
 Sodium acetate 120 grains 
 
 Water 12 ounces 
 
 A mixture of this and b (1) gives a fine tone after a fairly 
 long exposure. Another alkaline solution, b (3), may be tried, 
 it yields good tones of less warmth than those already given, 
 but the tones are good of their kind. 
 
 b (8). Potassium carbonate 360 grains 
 
 Potassium bromide 60 grains 
 
 Sodium acetate 120 grains 
 
 Water 12 ounces 
 
 To develop, take 1 0 minims of a , mix in a measure with 2 
 drams of £(1), or b(2 ), or of a mixture of b (1) and b(3), and 
 make up with water to half an ounce. The plate held on a 
 pneumatic holder is flooded with this, and the solution is to be 
 
LANTERN-SLIDES BY PHOTOGRAPHIC METHODS. 
 
 37 
 
 left on the plate, moving gently over it, but is not to be poured 
 off and on. This is our own method, but it may be prefera- 
 ble to use double the quantity of solution, and to develop in a 
 dish. The image ought to appear full of detail, but thin at 
 first, and to gain density gradually. With b (1) after a proper 
 exposure the development ought not to take more than two or 
 three minutes; a considerable amount of density ought to be 
 attained before development is stopped. Experience will teach 
 how long to go on. 
 
 The quality of the slide may to a considerable extent be 
 regulated by the quantity of a that is used. A large quantity 
 of a will tend to give brilliance and contrast, a small quantity, 
 say five minims, is likely to give harmonious effects. Mr. 
 Brooks uses five to ten drops of a and three drams of b (1). 
 
 After development and rinsing under the tap, fix in the 
 ordinary hypo., or better, with a solution of 
 
 Potassium cyanide 20 grains 
 
 Water 1 ounce 
 
 Remembering, however, that the cyanide is a strong poison, 
 toxic even by absorption. Wash carefully. If the slide is not 
 as clear in the high-lights as desired it may be flooded with a 
 solution of iodine thus: Tincture of iodine (pharmacopoeia) a 
 
 few drops in an ounce of water. Pour this on and off, 
 especially on foggy looking parts, for a couple of minutes, wash, 
 then apply the cyanide solution once more. 
 
 Intensification is apt to be a dangerous proceeding with a 
 slide, as there is a tendency to block up shadows ; still it may 
 be performed with success and good effect thus: After 
 
 careful washing, after fixing, flow over the plate, 
 
 Pyro 2 grains 
 
 Citric acid 2 grains 
 
 Alum (common) 2 grains 
 
 Water 1 ounce 
 
 After a few drams of a solution such as this have been 
 poured once or twice over the plate, add a drop or two of a 
 20 grains solution of silver nitrate in water, acidulated with 
 
33 
 
 LANTERN-SLIDES BY PHOTOGRAPHIC METHODS. 
 
 citric acid. Pour the mixture again repeatedly on and off, 
 taking care to avoid over density, and rejecting the solution 
 at once if it becomes muddy. 
 
 To tone or modify the warmth of a slide which happens to 
 be too warm for taste, after washing immerse in 
 
 Platinum chloride 1 grain 
 
 Nitric acid 1 minim 
 
 Water 3 ounces 
 
 till the desired tone is obtained. 
 
 To produce a beautiful engraving black, highly suitable for 
 copies of line subjects : Tone in platinum till the image 
 
 almost disappears by bleaching, or till it is considerably reduced 
 in strength, wash well, and intensify with the pyro-silver 
 solution, from which the alum may be omitted. 
 
 The greatest trouble we have ever found with this process 
 has been slipping of the film under washing. If the substratum 
 be properly applied, or the edging before coating, and before 
 development properly performed, slipping ought never to 
 occur. At the same time we must not use the plate so freely 
 under the tap as if it were a gelatine plate. 
 
 (For a 66 printing-out ” collodion emulsion process see page 59.) 
 
CHAPTER VII. 
 
 Gelatine Bromide Emulsion. 
 
 This process for making slides may safely be called tbe 
 standard process of the present day. Gelatine bromide offers 
 great advantages and conveniences on account of its sensitive- 
 ness, and if proper precautions be used and proper measures 
 resorted to, it will furnish slides which will bear comparison 
 with any slides that can be produced by purely photographic 
 methods. But to utilize its convenience we must not allow 
 ourselves nor our plate-makers to neglect the precautions nec- 
 essary to excellence. Though many plate-makers produce 
 emulsion fairly well suited for slide-making, there might be 
 improvement in every case we have yet noticed. We are pre- 
 pared to assert that gelatine-bromide emulsion, “slow” though 
 it is usually made, is in most cases not slow enough, and our 
 experience has been that the more sensitive have been the 
 commercial plates we have used, the larger our percentage of 
 failures or only mediocre results. The slowest emulsion we 
 have ever used for this purpose gave us the best series of 
 slides on gelatine-bromide we have ever made, and happily as 
 we made the emulsion ourselves we can give instructions for 
 its production. 
 
 Besides over-rapidity another fault is often found in com- 
 mercial slide-plates, viz. : the use of an unsuitable gelatine. 
 The heavily alumed, or hard gelatines seem to be better 
 adapted than softer, purer and sometimes alkaline samples, and 
 our experience is that with a hard gelatine there is less ten- 
 dency to formation of scum, due partially to salts in ordinary 
 tap water, than with a pure soft sample such as Nelson’s No. 
 1. Mr. W. B. Bolton prefers the softer and purer gelatines such 
 
40 
 
 LANTERN-SLIDES BY PHOTOGRAPHIC METHODS. 
 
 as Nelson’s, and his dicta are worthy of attention. He insists 
 on the use of distilled water throughout, but we find this 
 unnecessary if we use our acid alum finally. Another matter 
 requiring preliminary notice touches the haloid salts to he re- 
 commended. There is no doubt that a trace of chloride in the 
 emulsion tends to improve the color of the image, and it is 
 difficult to see of what advantage an iodide is likely to be in an 
 emulsion for our purpose, still the fact remains that the fine 
 emulsion to which allusion has just been made contained iodide 
 but no chloride, and we need hardly say that we will herein 
 give the result of frequent, not isolated experiment in formu- 
 lating a gelatine emulsion. W e shall give also a formula for a 
 very slow gelatin e-bromo-chloride emulsion which will work 
 very well, and may suit those who do not find their experience 
 of the bromo-iodide tally with ours. 
 
 Gelatine-Bromo-lodide Emulsion. — Place in an earthen 
 ware jar having a lid : 
 
 Gelatine (soft, as Nelson’s No. 1) 10 grains 
 
 Potassium bromide 70 grains 
 
 Cold distilled water 5 ounces 
 
 Soak 30 minutes. 
 
 Heat to about 130 deg. Fahr., stir well and see that solution 
 is complete. When at 130 deg. add in crystals, silver nitrate, 
 90 grains. This of course, is to be done in the dark room by 
 n on-actinic light. Yellow glass will not do for the window 
 when gelatine-bromide emulsion is in use ; the medium should 
 he clear ruby or several thicknesses of the orange colored 
 fabrics used for dark room windows. The emulsion is at no 
 stage anything like so sensitive as emulsion used for negatives, 
 but it is certain that much mischief arises from the worker 
 taking too great liberties with his lighting when using gelatine- 
 bromide plates however slow. As soon as the silver nitrate 
 begins to dissolve, which will be immediately, an emulsion will 
 be seen to he formed, and the liquid is to be stirred and kept 
 warm until the silver is all dissolved. Then add potassium 
 iodide, 2 grains, and hydrochloric acid 2 minims. Cover the 
 jar, place it in a vessel containing hot water, and boil for not 
 
LANTERN-SLIDES BY PHOTOGRAPHIC METHODS. 
 
 41 
 
 more than five minutes. Cool to about 140 degs. Fahr., then 
 add 100 grains hard gelatine — Heinrich’s, or Nelson’s X 
 opaque — this bulk-gelatine may be added dry, stir the whole 
 well up till the gelatine is entirely dissolved, then cool rapidly 
 by placing the jar in cold water or even iced water. The 
 emulsion should set in a stiff jelly, and is ready for washing, 
 unless it is to be separated by centrifugal action which we con- 
 sider preferable to washing in all cases, perhaps specially 
 preferable in slide emulsion making. 
 
 Note. — For a full account of “ Separation,” the reader is 
 requested to refer to “Processes of Pure Photography.” If 
 the worker proposes to separate, he will use in the original 
 solution of gelatine and soluble bromide, 20 grains of gelatine 
 in place of 10, and after the boiling he will cool to about 100 
 degs. Fahr., and separate briskly, for it will be found that full 
 time and force must be allowed for separation of so fine an 
 emulsion as this. Having poured off the liquid, if the drum 
 is a closed one, he will very gently rinse out the drum, and 
 then remove the silver bromide and traces of gelatine from the 
 sides of the drum. He is then to take 150 grains of hard gel- 
 atine, previously swelled, in 8 ounces of water and thoroughly 
 incorporate the silver bromide with the bulk-gelatine by vigor- 
 ous and prolonged stirring and heating to effect solution of the 
 gelatine. When solution and incorporation are complete the 
 emulsion is to be filtered, cooled and set, and it is ready for 
 use on being again melted by heat. 
 
 If washing is to be performed directions are given for the 
 operation a little further on. (Page 43.) 
 
 Gelatine-Bromo-Chloride Emulsion. 
 
 (See “ Processes of Pure Photography.”) 
 
 Gelatine — Nelson’s No. 1 30 grains 
 
 Soak in 
 
 Water 3 ounces 
 
 for a few minutes. 
 
 Add 
 
 Potassium bromide 138 grains 
 
 Potassium chloride 20 grains 
 
 10 per cent, dilution of hydrochloric acid 12 minims 
 
42 
 
 LANTERN-SLIDES BY PHOTOGRAPHIC METHODS. 
 
 Take also 
 
 Silver nitrate 200 grains 
 
 Water 3 ounces 
 
 Put the gelatine mixture into a flask or bottle capable of 
 holding at least 12 fluid ounces and heat it to about 120 degs. 
 Fahr. Heat also the silver nitrate solution to the same tem- 
 perature, take both into the dark-room, shake the gelatine 
 into a froth and then pour in a few drops of the silver, again 
 shaking well. The silver is to be added a few drops at a time, 
 with a hearty shaking after each addition, finally the vessel 
 that contained the silver is rinsed out with the gelatine mix- 
 ture, and a vigorous shaking for a couple of minutes completes 
 the emulsification. The emulsion is to be kept at about 140 
 degrees, for, say, an hour. It must not be boiled, as that 
 would make it too sensitive, but the operator may use his dis- 
 cretion as to temperature and duration of digestion. The 
 longer the time and the higher the temperature the more 
 sensitive and the more inclined to fog the emulsion will be. 
 
 For emulsion making it is essential that the chemicals be 
 absolutely pure and the weighing out accurate. Even when 
 attempting to make very slow and “robust” emulsion for 
 slides we got violent red fog on several occasions by using, as 
 we afterwards discovered, an alkaline and impure sample of 
 potassium bromide. In making the latter emulsion the silver 
 may quite well be added in crystals, in which case the water 
 used in our formula as solvent of the silver nitrate is added to 
 the gelatine solution. 
 
 After digestion we must get rid of the soluble products of 
 decomposition — nitrates chiefly — and we may “ separate” (see 
 above) or we may “wash.” If we are going to wash our 
 emulsion we add to the digested bromo-chloride emulsion, at 
 a temperature of about 130 degs. Fahr., 300 grains of a hard 
 gelatine, such as Heinrich’s, previously soaked in water, the 
 water being so far as possible squeezed out of the gelatine. 
 After tbis bulk gelatine is thoroughly mixed with the emulsion 
 and dissolved, the whole is cooled rapidly and ought to set 
 firmly. It is then cut or scraped, with silver or ivory imple- 
 
LANTERN-SLIDES BY PHOTOGRAPHIC METHODS. 
 
 43 
 
 ment, out of the vessel in which it set, and being divided into 
 small pieces is either put into a bag of wide-meshed muslin, 
 or into a glass or ebonite cylinder having a silver gauze or net 
 at one end ; the emulsion is forced with the hand through the 
 muslin by twisting the bag up, or through the silver meshes 
 by a u plunger,” fitting pretty accurately into the cylinder. 
 The end of the bag or cylinder is held under cold water as the 
 jelly is squeezed out. The shreds of jelly may be received 
 under water in a hair sieve sitting in an ordinary hand basin* 
 water is run into the basin from a tap for an hour at least, the 
 sieve being occasionally lifted out of the water, or a teapot 
 may contain the shreds, water running in by the spout and 
 the lid-hole being covered with muslin. The best article we 
 know for washing in this way, is the one designed by Mr. A. 
 L. Henderson, its strong point being, besides thoroughly wash- 
 ing the emulsion, that it can be used in daylight. 
 
 Better than this system is that of precipitation by alcohol. 
 Three or four times the bulk of alcohol that there is of emul- 
 sion is placed in a large jar, and the emulsion poured in a 
 fine stream into the spirits, with constant stirring. The clot 
 is to be removed, cut into small pieces and washed in running 
 water for some hours. 
 
 After washing, the shreds of gelatine are to be collected in a 
 piece of muslin, as much moisture squeezed out as pos- 
 sible, and solution effected by heat. Probably 9 or 10 ounces of 
 emulsion will be found to result from this treatment, less after 
 the alcohol treatment; a little alcoholic solution of thymol, 
 enough to make the emulsion smell distinctly of the latter, will 
 help to preserve the emulsion. 
 
 If we separate the emulsion after digestion, we add 300 
 grains of hard gelatine in 9 ounces of water to the bromide 
 left in the drum, and we add an ounce of alcohol and thymol 
 solution as above. 
 
 Filtering gelatine emulsion is most easily performed by use 
 of swansdown calico, previously dipped in hot water. The 
 gelatine must be hot during filtration, but not over 130 deg. 
 Fahr. 
 
44 
 
 LANTERN-SLIDES BY PHOTOGRAPHIC METHODS. 
 
 To Coat Glass Plates With Gelatine Emulsion. 
 
 We never attempt to coat plates so small as 3J inches square, 
 but use always plates 6^x3J, or 6^ inches square, cutting them 
 into two or four equal parts with a diamond and a very ingeni- 
 ous arrangement devised by Mr. Cowan, whereby we can in 
 the darkest of dark-rooms halve a plate without trouble. To 
 clean the plates : rub over a new plate, previously washed under 
 the tap, a cream of whiting and water, and let the cream dry 
 on the plate, then dust it oh and polish the plate with a clean 
 soft cloth. 
 
 We require a leveling-slab of plate glass, slate or marble 
 accurately leveled, and having, preferably, thin cords or piano- 
 strings stretched tightly over the top of the slab to prevent the 
 plates from sticking to the slab. The emulsion at about 100 
 deg. Fahr. may be poured onto the plate almost like collodion, 
 but very little should be allowed to run oh. We use a silver 
 ladle which holds half an ounce of emulsion and is provided 
 with a lip. The half ounce is about the right quantity for the 
 6^-inch square plate, for we do not require a very thick film. 
 As soon as ever we have got the emulsion to cover the plate 
 either by tilting the plate or by guiding the emulsion over it 
 with the ladle or a glass rod, we at once lay the plate down on 
 the level slab. When the emulsion is set, which depends on 
 the temperature and gelatine, but ought not to take longer 
 than two minutes, the plates are put into a drying-press, or 
 box. The requisites for drying are : supply of fresh air, and 
 removal of moist air from the vicinity of the plates ; in other 
 words, we must have a constant current of dry, pure air. A 
 room is the best drying place, if we can arrange to leave 
 and enter it without letting actinic light reach the plates, and 
 dust must be avoided. (For details of drying-boxes, etc., see 
 “ Processes,” or other literature dealing with gelatine-bro- 
 mide processes.) 
 
 The plates, when once dry, may be put in boxes or in 
 packets, but they must be kept in a place free from damp 
 and gaseous emanations, especially from house gas. 
 
CHAPTER VIII. 
 
 Gelatine Bromide, Continued. 
 
 Exposure and its results. With the wet collodion process 
 whatever exposure we may give we shall get an image by 
 development of a more or less blue color ; and though we may 
 by well executed operations make the color a very fine blue- 
 black, or real black, still we have hut little range of color. 
 But with emulsion processes in general we have always a cer- 
 tain range of colors within our reach ; dry collodion has a very 
 wide range, gelatine-chloride also, and gelatine-bromide prop- 
 erly treated is not far behind these in available range of tone. 
 An exposure much longer than that necessary to yield full 
 detail with the ferrous oxalate normal developer may he fol- 
 lowed by a heavily restrained pyrogallol development with the 
 result of very warm tones ; hut a short exposure such as 
 requires a fairly powerful developer will never yield warm 
 tones, never at least has done so in our experience. If we 
 wish warm tones we must give a long exposure and develop 
 with a heavily restrained or naturally weak pyrogallol devel- 
 oper. Medium tones may be got by medium exposure and 
 medium strength of development. 
 
 Several systems of development will be described here, and 
 to help the beginner we shall suppose that the exposure (reduc- 
 tion in the camera by daylight) necessary for the ferrous oxa- 
 late developer as formulated, or the quinol caustic one, is one 
 minute. By using our quinol-carbonate, or pyro-ammonia or 
 pyro-carbonate developer, medium tones will be obtained after 
 an exposure of two to four minutes, and the use of our pyro- 
 
46 
 
 LANTERN-SLIDES BY PHOTOGRAPHIC METHODS. 
 
 and carbonate of ammonia developer will give very warm 
 tones after exposure of from eight to twelve minutes. The 
 point is to be able after one of these very protracted exposures 
 to avoid fog. 
 
 Ferrous oxalate developer, which will give good but cold 
 tones : 
 
 a. Iron protosulphate 1 part by weight 
 
 Water 4 parts 
 
 Sulphuric acid .1 dram to each pint of the above 
 
 b. Potassium oxalate 1 part 
 
 Water 3 parts 
 
 Or a cold saturated solution may be kept, the bottle being 
 occasionally shaken, and some crystals always visible at the 
 bottom. 
 
 c. Potassium bromide % chemical ounce 
 
 Water to 10 fluid ounces 
 
 The developer : Pour 1 part of a into 5 parts of b, and for 
 each ounce of the mixture add 1 0 minims of c. 
 
 Quinol-caustic developer. Cold tones, or cold medium. 
 
 a. Quinol (or hydroquinone) 80 grains 
 
 Added to 
 
 Sodium sulphite 1 ounce 
 
 Citric acid 30 grains 
 
 Potassium bromide 30 grains 
 
 Water to. . . 20 ounces 
 
 Dissolved together. 
 
 b. Potassium, or sodium hydrate 80 grains 
 
 Water to 20 ounces 
 
 The developer : Equal parts of a and b. 
 
 The water of b must be fresh distilled, or ordinary boiled 
 for ten minutes. 
 
 Quinol carbonate (Mr. B. J. Edwards.) Medium tones : 
 
 Sodium sulphite 2 ounces 
 
 Water (hot) 20 ounces 
 
 Quinol 30 grains 
 
 Sodium carbonate (pure) 3 ounces 
 
 Potassium carbonate 3 ounces 
 
 Potassium bromide .40 grains 
 
LANTERN-SLIDES BY PHOTOGRAPHIC METHODS. 
 
 47 
 
 This may be made up in two solutions which, separately, 
 will keep for a long time. To do this dissolve the sulphite, 
 quinol and bromide in 7 ounces of water, the remainder in 13 
 ounces, or 6 and 14 ounces. 
 
 Pyro-meta-bisulphite developer. (Mawson & Swan.) Warm 
 or cold tones, according to exposure. A developer of great 
 
 merit : 
 
 a. Pyrogallol 40 grains 
 
 Potassium meta-bisulphite 120 grains 
 
 Water to 20 ounces 
 
 b. Liquor ammonia fort 2^ drams 
 
 Ammonium bromide 40 grains 
 
 Water to 20 ounces 
 
 The potassium salt is patented, but can be obtained easily in 
 England. As we always use it for preserving our pyro, we 
 give our ordinary negative formula, but for warm toned slides 
 the “ meta ” may be increased three times at least. 
 
 Ordinary negative pyro solution : 
 
 Dissolve 
 
 Potassium meta-bisulphite 1 ounce (avoir.) 
 
 In 
 
 Water 7 ounces 
 
 Add 
 
 Pyrogallol ... 1 ounce (avoir.) 
 
 Make up to 9 ounces (fluid) 
 
 Filter and label “ Pyro. 10 per cent. 10 minims = 1 grain 
 pyro.” 
 
 If we make up ten per cent, solutions of ammonia and bro- 
 mide — thus : 
 
 Liquid ammonia fort 1 ounce 
 
 Water to 10 ounces 
 
 and 
 
 Ammonium bromide 
 Water to 
 
 1 ounce (avoir.) 
 9 ounces (fluid) 
 
48 
 
 LANTERN-SLIDES BY PHOTOGRAPHIC METHODS. 
 
 we may make a very good developer for slides thus : 
 
 Pyro solution 15 minims 
 
 Bromide solution 20 or 30 minims 
 
 Ammonia solution 20 minims 
 
 Water to 1 ounce 
 
 The amount of bromide to depend on the exposure. The 
 more bromide (restrainer) our exposure will allow us to use the 
 warmer, probably, will be our resulting tone. 
 
 Pyro, ammonia, and ammonium 
 (Thomas & Co). Por warmish tones, 
 
 carbonate developer 
 but must be used with 
 
 care. 
 
 
 1. Pyrogallol 
 
 Sodium sulphite 
 
 Citric acid 
 
 Water 
 
 
 2. Liquor ammonia 
 
 Water 
 
 
 3. Ammonium bromide 
 
 Water 
 
 
 4. Ammon, carb 
 
 Water 
 
 
 The developer — for warm tones. No. 1, 30 minims ; 
 No. 2, 30 to 60 minims ; Nos. 3 and 4 each 60 minims ; water 
 to 2 ounces. 
 
 Pyro and ammonium carbonate. Warmest tones. 
 
 A. Pyrogallol as Messrs. Thomas’, above. 
 
 B. Ammonium carbonate, fresh, clear, not amor- 
 
 phous crystals 1 ounce 
 
 Water to 10 ounces 
 
 The developer : 
 
 A . .10 minims 
 
 B 2 drams 
 
 Water to 1 ounce 
 
 Bromide, if desired 3 4 S ra ' n 
 
 With very long exposure this will give very warm tones, 
 which may be further modified by the acid-iron-alum solution 
 given below. 
 
LANTERN-SLIDES BY PHOTOGRAPHIC METHODS. 
 
 49 
 
 Finally, mention may be made of Mr. Carbntt’s Developer, 
 which we have used with satisfaction. It gives a good range 
 of tones. 
 
 Car butt’s ferro-citro- oxalate developer: 
 
 A. Potass, oxalate 8 ounces 
 
 Water 30 ounces 
 
 Citric acid 60 grains 
 
 ^Ammonium citrate solution 2 ounces 
 
 B. Ferrous sulphate 2 ounces 
 
 Sulphuric acid 8 minims 
 
 Water. . . 32 ounces 
 
 The developer is : 
 
 A f 2 ounces 
 
 B 1 ounce 
 
 (Potass, bromide, if desired *4 a grain) 
 
 We cannot with any approach to accuracy give directions 
 as to length of exposure, but having already taken as a hypo- 
 thetic standard one minute as an exposure suitable for camera 
 reduction by daylight, we may now say that for contact-print- 
 ing on gelatine-bromide plates an exposure to an ordinary gas- 
 burner of 12 seconds at 10 inches distance may be a good 
 starting point for ferrous oxalate or quinol-caustic development. 
 The quinol-carbonate, or Thomas’ pyro-carbonate and ammonia 
 developer will require perhaps 30 to 50 seconds, while our 
 ammonium carbonate as the only alkali will require for warm- 
 est tones not less than 3 minutes. Experiment and careful 
 observation of results alone will teach the proper exposure for 
 this as for all other photographic operations. Ho matter what 
 developer we use, if our image rushes up rapidly, thin and 
 veiled, our exposure has been too long ; on the other hand, if 
 our slides are wanting in half tones either in shadows or high 
 lights ; if they have black and white in close juxtaposition ; 
 if they have any very dense or opaque parts we have probably 
 under-exposed. We can say no more. If a slide is improperly 
 exposed the only sensible step to take is to make another 
 exposure, no dodging of development is ever satisfactory. 
 
 * The ammonium citrate solution is made thus : Dissolve 1 ounce of 
 citric acid in 5 ounces of water, add liq. ammonia till neutral, then make 
 up to 8 ounces. 
 
50 
 
 LANTERN-SLIDES BY PHOTOGRAPHIC METHODS. 
 
 Manipulations of Development are so simple as hardly to 
 require notice. The plate is placed film upwards in a dish 
 and the developing solution is poured quickly over it, the 
 plate being wetted all over its surface at once. If the devel- 
 oper is weak or heavily restrained in any way the image may 
 not begin to appear for a minute ; the Mawson metabisulphite 
 and the carbonate of ammonia developers take at least a 
 minute, sometimes more, to produce any visible image. 
 But ferrous oxalate and quinol caustic as formulated ought 
 to act more quickly and will do so if exposure has been 
 sufficient. With some developers we require to push develop- 
 ment further than with others, and the plates used make a 
 considerable difference in this respect. But in all cases we 
 must not stop development till we have an image, seen by 
 transmitted light, considerably denser than we wish the final 
 image to be. The ammonium carbonate developer acts in a very 
 curious way with hard tap water, a scum seems to form all over 
 the plate, but disappears on fixing, and the image on being 
 washed under the tap before fixing becomes decidedly darker 
 than when it left the developer. With ferrous oxalate and 
 quinol developers we watch first the shadows, these must have a 
 certain amount of density if the slide is not to be weak ; but 
 sometimes we have to make allowance — as when our negative 
 is thin — for fog coming over our highest lights, and so we 
 may have to stop the operation before the shadow details are 
 fully up to our standard of density. It must be remembered 
 that a slide however dense may easily be reduced after fixing, 
 and this reduction often improves a slide in other ways besides 
 mere general reduction of density. 
 
 When development is judged to be complete the plate is 
 washed under the tap, but if developed by ferrous oxalate or 
 ferro-citro-oxalate, it should get two or three rinses in water 
 acidulated, perceptibly to the sense of smell, with acetic acid. 
 Citric acid, or almost any acid will answer, but the acid is to 
 be washed out before the plate is put to fix in the hypo. The 
 acid is used to insure elimination of the iron from the film. 
 
 Scum, likely to be formed by combination between the oxa- 
 
LANTERN-SLIDES BY PHOTOGRAPHIC METHODS. 
 
 51 
 
 late and salts in tlie water, is removed easily at a later stage. 
 There is no harm, nor any use that we know of, in putting 
 the plate into alum before fixing, hut it is sometimes recom- 
 mended. The beginner must not trifle with his light for 
 developing bromide plates ; one thickness of yellow fabric is 
 not safe ; we know that many slides are spoilt by carelessness 
 in this matter. 
 
 Fixing Solution. 
 
 Sodium Hyposulphite 1 part 
 
 Water 5 to 6 parts 
 
 Must not he acid, and the plate must remain for ten 
 minutes. 
 
 Thereafter wash very thoroughly, unless reduction by ferri- 
 cyanide is to be practiced. 
 
 It may be taken, as a rule, that some clearing is necessary 
 with most, and useful with all, slides. The clearing solution 
 works best when poured onto the plate, not when a dish is 
 used. 
 
 C 
 
 Solution For Clearing. 
 
 Put into a large bottle some alum and some citric acid and 
 add water. Alum and acid are always to be visible at the 
 bottom, and the solution should be shaken or stirred now and 
 again. To use : take four ounces of the supernatant liquid 
 and add one dram of hydrochloric acid, pour on and off the 
 plate many times ; any scum there may be will be dissolved by 
 this. We recommend that this operation be never omitted. 
 
 In order to clear and also to modify the tone of a slide we 
 use a suggestion of Mr. B. J. Edwards. We take a clearing 
 solution as above, but we replace one-half of the acid-alum 
 solution by an equal quantity of cold saturated iron sulphate 
 solution, in fact, usually by the iron of our ferrous oxalate 
 solutions. This markedly improves the tone of a quinol-caus- 
 tie slide, also that of a meta-bisulphite or quinol-carbonate 
 slide, but it has a very remarkable effect on an ammonium- 
 carbonate slide, which is presumed to ha> c already a warm brown 
 
52 
 
 LANTERN-SLIDES BY PHOTOGRAPHIC METHODS. 
 
 tone. The solution in this case entirely alters the color of the 
 image, and by graduating the amount of the hydrochloric acid 
 and of the iron, we can go through a series of very useful 
 tones. But we should do this by daylight, for hy gas light 
 one is very apt to overdo the action and produce slides of a 
 blue that may almost be termed ghastly. The author puts 
 forward the ammonia carbonate developer followed by this 
 clearing-toning solution, as the best way he knows to get really 
 warm tones on gelatine-bromide slide plates. If reduction by 
 iron perchloride is to follow, the iron-acid-alum solution is to 
 be used before reduction ; it will fail after it probably. 
 
 Reduction of Density , by Potass. Ferricy anide, (or Fer^ 
 ridcyanide) and Hypo. (Mr. Howard Farmer.) 
 
 1st. Lay the plate in fresh sodium hyposulphite solution. 
 
 2d. Pour into a measure, say, 2 drams potass, ferricyanide 
 solution 10 per cent, in water. 
 
 3d. Pour the hypo, from the plate into the measure and 
 pour the mixture upon the plate, but be careful not to overdo 
 the reducing action which will start at once. 
 
 Ho iron must be allowed to contaminate the ferricyanide 
 solution ; If this occurs a fine green will follow and stain the 
 plate almost indelibly. If the ferricyanide itself slightly stains 
 the plate, the alum-acid solution — without the iron — will 
 remove the stain. 
 
 By Iron Perchloride and Hypo. (Mr. Cowan.) 
 
 Mix: 
 
 Iron perchloride (pharmacopoeia tincture) 2 drams 
 
 Hydrochloric acid 4 drams 
 
 Water to 20 ounces 
 
 Place the plate for a couple of minutes in the above, then 
 wash, then place in fresh hypo, solution till the desired effect 
 is obtained. If the action is insufficient repeat the operations. 
 But if the plate not freed from hypo, be placed in the iron 
 perchloride, the reduction will be very great, even to danger 
 of spoiling the slide entirely. 
 
 If there is occasion to make slides from negatives of line 
 subjects such as engravings, diagrams and the like, quinol with 
 
LANTERN-SLIDES BY PHOTOGRAPHIC METHODS. 
 
 53 
 
 a very powerful restrainer will yield results unsurpassed by any 
 other gelatine process. The exposure will require to be long 
 and development will be very slow but the result will be 
 absolute clear glass and opacity and an absence of the lateral 
 development which so frequently spoils line images on gelatine 
 plates. 
 
 The quinol solution may be made thus : 
 
 Quinol 40 grains 
 
 Meta bisulphite of potash 40 to 60 .grains 
 
 Potass, bromide 40 grains 
 
 Water to 10 ounces 
 
 Equal parts of this, and a solution as follows : 
 
 Sodium or potassium hydrate. 80 grains 
 
 Water to 10 ounces 
 
 Twenty minutes may be required for development, and the 
 dish must be occasionally moved ; if the exposure has been 
 right the result above mentioned may be expected. A similar 
 developer may with great advantage be used in making nega- 
 tives of line subjects. 
 
 Gelatine slides should certainly be varnished with a clear 
 varnish such as will be found mentioned on page 29. Var- 
 nishing clears up the slide considerably, as well as protecting 
 the film from damp which may easily occur even in a mounted 
 slide. 
 
CHAPTEK IX. 
 
 Gelatine-Chloride Emulsion. 
 
 The following is a formula given a good many years ago by 
 Mr. Alex. Cowan, and we have not found any formula more 
 workable or more satisfactory. 
 
 a. Sodium chloride 48 grains 
 
 Water 1 ounce 
 
 b. Silver nitrate 96 grains 
 
 Water 2 ounces 
 
 Gelatine (Nelson No. 1 and Heinrich equal parts). .96 grains 
 
 Soak the gelatine in the water of a for an hour, then add 
 the chloride of a and one minim of hydrochloric acid. Melt 
 the gelatine at 130 degs. Fahr., take into the dark-room and, 
 at the same temperature, add b with shaking. Keep at 130 
 degs. for about 5 minutes. Pour into a dish to set, or let it 
 set in the original vessel if the latter is of such a shape that 
 the jelly can be easily removed. Break, tear, or cut it up into 
 small pieces, or shreds, and wash as for gelatine-bromide emul- 
 sion (see page 43). The coating of the plates is also to be 
 performed as for gelatine bromide, but a plate coated with the 
 chloride emulsion will appear much more transparent than one 
 coated with bromide emulsion. In fact a plate well coated 
 with chloride emulsion is so transparent and the film so glossy 
 that without breathing on the plate it is often difficult to tell 
 which is the glass and which the film side. The glass side, of 
 course, will u take” the moisture of the breath and the gelatine 
 side will remain undulled. 
 
LANTERN-SLIDES BY PHOTOGRAPHIC METHODS. 
 
 00 
 
 In all processes where gelatine is used for slide making 
 distilled water alone should be used in the emulsion. 
 
 The exposure with such an emulsion as described may be 
 made by contact to diffused daylight or a few inches of mag- 
 nesium wire or ribbon burned. A medium dense negative 
 may require 5 to 10 seconds to diffused daylight for warm 
 tones. As with most other processes for slide-making a cold 
 tone may be obtained with a comparatively short exposure 
 and powerful developer. 
 
 MraB. J. Edwards’ Developer. — (Cold tones). 
 
 a. Neutral oxalate of potash 2 ounces 
 
 Chloride of ammonium 40 grains 
 
 Distilled water 20 ounces 
 
 b. Sulphate of iron 4 drams 
 
 Citric acid. 2 drams 
 
 Alum 2 drams 
 
 Distilled water 16 ounces 
 
 Equal parts of the above form the Developer. 
 
 Mr. A. Cowan’s Developers for Chloride Plates. (Examples.) 
 
 No. 1. — (Cold tones). 
 
 Potassium citrate 136 grains 
 
 Potassium oxalate 44 grains 
 
 Distilled water (hot) 1 ounce 
 
 No. 2. — (Medium warm tones). 
 
 Citric acid 120 grains 
 
 Ammonium carbonate 88 grains 
 
 Distilled water (cold) 1 ounce 
 
 No. 3. — (Warmest tones.) 
 
 Citric acid 180 grains 
 
 Ammonium carbonate 60 grains 
 
 Distilled water (cold) 1 ounce 
 
 Three parts of any one of the above to be mixed with one 
 
 part of 
 
 Proto-sulphate of iron 140 grains 
 
 Sulphuric acid 1 minim 
 
 Distilled water 1 ounce 
 
56 
 
 LANTERN-SLIDES BY PHOTOGRAPHIC METHODS. 
 
 In Nos. 2 and 3 above, when the acid and the alkali are 
 mixed in solution there will be considerable effervescence, so 
 the solution or mixture should be performed in a larger vessel 
 than is required to hold the quantity actually made up. 
 
 A restrainer is sometimes required in case of over-exposure 
 or thin negatives, in this case a minim or two of a ten per cent 
 solution of potassium bromide for No. 1, sodium chloride for Nos. 
 2 and 3, may be added to each ounce of developing solution. 
 
 Washing and fixing are as for bromide plates. 
 
 The development must not be stopped too soon, the plates 
 may appear fogged after a certain amount of development, but 
 will emerge clear from the hypo solution. Mr. Cowan even 
 recommends over-development and reduction, after fixing and 
 washing, in the perchloride of iron reducer given under 
 gelatine-bromide on page 52. 
 
 Gelatine-chloride emulsion produced by such a formula as 
 we have given may be made much more sensitive by keeping 
 hot after emulsification for some hours, or even by boiling for 
 a few minutes, but this practice we cannot recommend, as with 
 chloride there is much risk of fog in such cases. 
 
 \ 
 
 t 
 
CHAPTER X. 
 
 Henderson’s Argentic Stain. — Transferotype (Eastman.) 
 
 By a process published some years ago by Mr. A. L. Hen- 
 derson, and us^d experimentally by the writer, results were 
 obtained more decidedly fulfilling certain desiderata than any 
 other process we have ever seen. The image seems really to 
 consist of a stain rather than of a molecular precipitate of a 
 metal, but of course it is a reduction and not a stain. The pro- 
 cess is one of printing out and subsequent toning, and we give 
 it as a good example of processes which might be classed under 
 that one head. 
 
 No. 1. 
 
 Soak and then dissolve at low temperature : 
 
 Gelatine 
 
 In 
 
 Water 
 
 Add 
 
 Sodium acetate 
 
 No. 2. 
 
 Silver nitrate 170 grains 
 
 Water 10 ounces. 
 
 No. 3. 
 
 Sodium citrate 80 grains 
 
 ' Sodium chloride 20 grains 
 
 Water ' 4 ounces 
 
 Add Ho. 2 to No. 1, then add No. 3, all the solids being of 
 course dissolved, and the temperature low. 
 
 Lastly, add 2 ounces of dry, hard gelatine, see that all is 
 dissolved, make up with water to 30 ounces and coat the plates 
 rather thickly. Dry in a drying press or closet in the usual 
 
 240 grains 
 10 ounces 
 46 grains 
 
 wav. 
 
58 
 
 LANTERN-SLIDES BY PHOTOGRAPHIC METHODS. 
 
 Print deeply by contact in daylight ; the printing will be 
 rather slow. Do not wash the plates after printing, but place 
 them directly in the toning-bath which is recommended by 
 Mr. Henderson as follows : 
 
 Gold chloride 2 grains 
 
 Sodium acetate 20 grains 
 
 Sodium chloride.. . . 20 grains 
 
 Water 10 ounces 
 
 Neutralize the acidity with chalk, filter out the chalk and 
 then add 3 minims of acetic acid. 
 
 The plate is treated with this solution, till it takes a suitable 
 tone ; it will go through various changes of color during the 
 operation, and the longer the action is allowed to continue the 
 colder will be the tone. 
 
 The writer toned plates produced by this formula with the 
 
 sulpho-cyanide bath, and got very good results. 
 
 Ammonium sulpho-cyanide .... 140 grains 
 
 Sodium phosphate 140 grains 
 
 Sodium tungstate 100 grains 
 
 Water 24 ounces 
 
 Dissolve and allow to stand for a day or two. Then add : 
 
 Chloride of gold 15 grains 
 
 Water 4 ounces 
 
 This bath is apt at first to act unevenly, especially if used 
 too new. 
 
 After toning by either of these methods, and washing, fix 
 the slides in weak hypo, thus : sodium hyposulphite 1 part, 
 water 10 parts. Thereafter wash thoroughly, dry, and varnish 
 with clear varnish. 
 
 A strong point of this process is that combination printing 
 of clouds, etc., is very easy. 
 
 Slides on Eastman TransferotYpe Paper. 
 
 This is another process which in certain cases has answered 
 our purpose admirably. By the Eastman Company of 
 Rochester, U. S. A. paper is coated first with soluble gelatine, 
 next with an insoluble emulsion of gelatine-bromide of silver. 
 After contact printing by artificial light and development 
 usually with ferrous oxalate, the paper print after fixing and 
 washing is squeegeed into contact with a glass plate of slide 
 
LANTERN-SLIDES BY PHOTOGRAPHIC METHODS. 
 
 59 
 
 size. After a time liot water is applied to the whole and the 
 paper comes off, leaving the positive image adhering to the 
 glass. After very careful washing in hot water to remove 
 surplus gelatine the plate is cleared with alnm and acid, dried 
 and varnished. Such a slide looks much better on the screen 
 than might be expected from inspection in the hand. As the 
 Eastman Company, according to our information, do not pro- 
 pose to continue the manufacture of transferotype we need 
 not enter fully into the process. 
 
 Collodio-chloricle emulsion furnishes a very fine printing-out 
 process corresponding in collodion to the argentic stain in 
 gelatine. This process was worked to a considerable extent 
 many years ago but fell into disuse. For lantern-slides it is 
 very useful and the process is simple. We have just lately 
 refreshed our memory by making some of the emulsion, 
 working on the lines given in the u Year Book of Photog- 
 raphy, 1874.” Dissolve 15 grains silver nitrate in 15 minims 
 of boiling water ; put this into 1 ounce of a good sample of 
 plain (unsalted) collodion. Then add in yellow light 3 grains 
 of calcium chloride dissolved in the smallest possible quantity 
 of alcohol ; finally add 1 grain of citric acid. In making this 
 emulsion the usual precautions of gradual addition and shaking 
 are to be observed. The plates albumen ized as for collodion 
 emulsion (page 32) are coated with the collodio-chloride, and 
 when set are dried by moderate heat ; or the plates may be 
 edged with albumen or india rubber ; or, previous to toning, a 
 tallow candle may be run around the edges. Print very 
 deeply, wash shortly under a rose tap, and tone in any 
 ordinary toning bath. We used the common acetate gold bath. 
 
 Sodium acetate 25 
 
 Gold chloride 1 grain 
 
 Water 8 ounces 
 
 Kept not less than 24 hours before use. 
 
 The image leaves the printing frame in a red state and may be 
 toned to any desired color attainable by gold toning. Fix in very 
 weak hypo solution, wash under a rose tap, dry, and varnish. 
 
 This process is well worthy of trial ; like the argentic stain, 
 it allows of easy introduction of clouds, etc. 
 
CHAPTER XI. 
 
 Coloring .lantern Slides. 
 
 The writer has to confess that he has no experience in the 
 matter of coloring slides, and that he is nnable to discover the 
 beauty or advantage of painted lantern-slides, but there is 
 no doubt that well-colored slides are popular with the public, 
 and indeed we fear it must be acknowledged that many of the 
 public think that without color a slide is a very poor article. 
 Children, too, are very partial to bright colors, and for the 
 sake of the little ones, if for no other reason, we propose to 
 devote a chapter to slide-painting. As, however, we are not 
 personally conversant with the process we have secured the 
 services of a friend who is thoroughly “ up ” in the matter, 
 and whose name, had we permission to give it, would be suffi- 
 cient guarantee of the value of the instructions. 
 
 In the first place it should be understood that the slide is not 
 to be varnished ; if the positive be in gelatine no treatment is 
 required ; if it be collodion the film should have a coating of 
 albumen. 
 
 The work of painting on a slide is by no means so easy as it 
 might appear to one who has not tried it, and the chief diffi- 
 culty is the mechanical one of applying the pigments to the 
 smooth surface of the picture. Brushes are used in the first 
 place, but if no special treatment followed their use, a painted 
 slide would on a screen show marks of every hair in the 
 brush. 
 
 The tints, whatever they may be in color, must of course be 
 transparent, and so we are limited at the very outset to choice 
 of only a few pigments of the many that are available for 
 ordinary painting. Water colors are not to be recommended 
 
LANTERN-SLIDES BY PHOTOGRAPHIC METHODS. 
 
 61 
 
 for our work, and colors for the purpose of painting on glass 
 are sold by some dealers. We find, however, little or no 
 difference between these “special” colors and the ordinary 
 oil-colors sold in tubes by artists’ color men. Very little color 
 goes a long way on a lantern slide, and motives of economy 
 should not prevent us from buying the very best quality. The 
 following list of transparent pigments will probably suffice for 
 all requirements. Reds : the various madders, crimson lake. 
 Chinese orange. Yellows: Italian pink, raw sienna, brown 
 sienna. Blue : Prussian. Accessories : ivory black and 
 McGilp. f 
 
 This does not seem a very liberal supply of pigments, but 
 it must be remembered that very many tints may be obtained 
 by judicious mixture, and the colors we have named are con- 
 spicuously transparent and so suitable. The Ivory black is 
 useful in compounding certain tints, notably “ neutral ” tones. 
 This black with brown sienna and a red will yield a fine warm 
 brown, with brown sienna and a blue it will give a fine neutral 
 grey. Greens are to be obtained by suitable admixture of 
 yellow and blue, tempered to taste by other colors. 
 
 We shall require a small easel to be kept in a sloping posi- 
 tion, and it should have a pane of clear glass as a backing for 
 the lantern picture which will rest on a bar of wood stretching 
 across the pane of glass. In fact, a small photographic 
 retouching desk is the very thing needed. A small mahl- 
 stick and a palette will be required, the latter may be of 
 white porcelain and should be kept clean, the paint being 
 removed from it with a palette knife after each time of use, 
 and the palette being then cleaned with turpentine. 
 
 Camel-hair brushes, and a few sables such as are used by 
 miniature painters, will be found necessary. Four small 
 phials will hold the following : 
 
 1. Rectified turpentine. 
 
 2. Canada balsam, ten parts ; turpentine, one hundred parts. 
 
 3. Copal varnish and turpentine, equal parts. 
 
 4. Japanner’s gold size. 
 
 Further, we shall need a small cup or pot to hold turpen- 
 tine, in which the brushes are to be cleaned. 
 
62 
 
 LANTERN-SLIDES BY PHOTOGRAPHIC METHODS. 
 
 The easel is to be placed near a window with a good steady 
 light, facing north by preference, in a room free from dust 
 and kept at moderate temperature. 
 
 Suppose we have to make our first attempt at coloring a 
 slide, and let us suppose the slide to have a sky represented 
 by clear glass. A little of our Prussian blue is squeezed out 
 of the tube (the size of an ordinary grain of wheat is enough), 
 by its side on the palette is placed a little McG-ilp ; the brush 
 wetted with turpentine is used to mix a little of the blue 
 and a little of the McGilp until the right tint is produced. 
 This is then applied in even strokes from side to side on the 
 sky of the slide and may even encroach a little on the land- 
 scape. The turpentine is allowed a minute to evaporate, and 
 then the soft pad of one finger is used to dab the color evenly 
 all over the sky of the slide. The dabbing must be kept up 
 till the effect is even all over, and the softer the pad of the 
 finger the better the result ; the finger may be rubbed well 
 with pumice stone to make it smooth. This operation of dab- 
 bing requires some perseverance, and, we need hardly say, 
 some practice before it will be executed to perfection. A few 
 clouds may next be “ wiped out ” with a piece of white kid 
 twisted round the end of a penholder or small stick, the posi- 
 tion of the kid must be frequently altered on the stick so as 
 to present to the slide a clean surface of kid. Distances and 
 shadows may be next filled in with purple made by mixing 
 crimson lake and blue, and these masses are to be dabbed as 
 the sky was. Next, any paint that may have gone beyond 
 the intended limits may be wiped off with the kid, and then 
 then the whole plate is to be evenly heated before a clear fire, 
 every precaution being taken against dust. The heating 
 makes the pigments beautifully transparent. 
 
 After about an hour the slide will be dry, and the rest of the 
 painting may then be carried out with a brush. Dabbing 
 cannot be executed on small masses. 
 
 Certain colors will be found to work best with certain media. 
 Thus the reds are notoriously slow driers, and are best laid on 
 with gold size. The copal mixture will do for most of the 
 
LAN TERN-SLIDES BY PHOTOGRAPHIC METHODS. 
 
 63 
 
 other pigments ; but Canada balsam may be found best adapted 
 for laying on the yellows. These are all matters for experi- 
 ment and of experience. As soon as the painting is finished 
 the slides should be mounted. 
 
 Though such a matter does not really come under our special 
 subject, we may give a few systems of drawing diagrams and 
 designs upon glass to serve as lantern-slides. 
 
 Dr. Dallinger produces a very fine grain on glass by grind- 
 ing two pieces together with emery flower and water between 
 them. He then draws his design with a pencil on the ground 
 surface ; the design is colored with water colors, transparent 
 ones being used. Finally the slide is varnished with spirit 
 varnish which obliterates the grain produced on the glass by 
 the grinding. If it is found that the colors are not inclined to 
 be smoothly on the surface, a little treatment of the latter with 
 ox gall will set matters right. 
 
 If a glass plate be licked all over with the tongue and 
 allowed to dry, a pen and ink will write on it easily, and with- 
 out running. The writing may be strengthened by dusting 
 over the plate soot, or some such material. After such treat- 
 ment the plate will stand any moderate amount of rubbing 
 without losing the design on it. 
 
CHAPTER XII. 
 
 Masks — Mounting. 
 
 When a slide has been varnished all that remains to be done 
 is the choosing of a mask and the mounting of the slide in 
 such a way that it will he protected from scratches, dust, 
 atmospheric influence, etc. 
 
 Cover-glasses are used of the same size as the slides. These 
 covers are carefully cleaned with spirits and ammonia, or with 
 whitening ; glasses that have flaws, as scratches, ridges, bub- 
 bles, or strise, are to be rejected. 
 
 As to masks. The best and most convenient are white on 
 one side and black on the other ; the white is suitable for bear- 
 ing the name of the subject and also for showing which is the 
 front of the slide. TJntil lately the apertures cut in masks 
 were confined to a few shapes and proportions, nearly all bad. 
 It is very rarely that a circular or square or cushion shaped 
 aperture of standard proportions suits the composition of a 
 picture taken on an oblong plate, and clearly a slide ought to 
 carry out the intention of the artist as much as a paper print. 
 A gentleman of New York, we believe, first called public 
 attention to the shapes of mask apertures, and much improve- 
 ment has been the result. Bor ourselves we have for long 
 used masks of oblong shape, some rounded at the corners, 
 some not so ; oblong apertured masks can at all events be easily 
 got to order in Britain at the present time. The price of 
 masks seems to be singularly high, and it will repay those who 
 use many masks to get templates made of proper size and with 
 suitable apertures, and with a Robinson’s Trimmer to cut out 
 their own masks, as we did for many years. 
 
 The slide is laid on a table, film side upward, and a mask is 
 laid in position, white side — if any — uppermost. A cover- 
 
 glass is laid on the mask, and the whole is ready for mounting. 
 
LANTERN-SLIDES BY PHOTOGRAPHIC METHODS. 
 
 65 
 
 There is great variation in the qualities of the gummed 
 strips procurable in this country. Some adhere well, some 
 not at all ; some are too thick, some too thin, some too wide, 
 some too narrow. Some adhere for a long time, some leave 
 the glass very soon. The fact is, that most of those who make 
 our strips have no practical knowledge of our requirements 
 Still good gummed strips can be purchased. They should be 
 about fourteen inches long and about oneffhird of an inch wide ; 
 not so thick that they spring away from the glass as the 
 slide is turned over in process of mounting ; what is called 
 “needle-paper,” Answers well. We believe that there should 
 be some sugar in the mucilage to secure adhesion to glass. 
 When we wish to ensure a very long life to our slides we gum 
 our own strips with thin glue, to which, at the suggestion of 
 Mr. G. W. Wilson, of Aberdeen, we add a little oil of laven- 
 der. A very good system, recommended to us by one whose 
 name we unfortunately forget, is to mount with a thin, porous 
 paper such as tissue-paper, and thereafter to dip the edges of 
 the slide in a spirit varnish, such as shellac. 
 
 The operation of mounting is very simple. The strip being 
 wet except one inch at one end, and laid at full length on the 
 table, one side of the slide is pressed down at one end and in 
 the middle of the breadth of the strip, the slide is now turned 
 over on to its next side, the corners being pinched in and 
 turned over with the finger and thumb of the free hand. 
 This is repeated to the last corner, where the surplus of strip 
 is cut or sharply pulled off. The fingers should run along the 
 sides many times, and care should be taken that the strip 
 adheres to the glass at the ends as well as at the turn-over. 
 This entire system of binding slides with paper is bad, and the 
 sooner we get something more durable and equally convenient 
 the better. 
 
 The slide being mounted we require to affix some marks by 
 which the lanternist may know in what position to put the slide 
 into the carrier. In Britain the generally accepted standard is 
 this : Lay the slide as the picture appeared in nature or is to 
 
 appear on the screen, then place a mark at each of the two top 
 corners ; a white mark on a black mask and vice-versa. 
 
CHAPTER XIII. 
 
 Reduction by Artificial Light. Combination Printing. 
 
 Reduction in the Camera by Artificial Light. With mod- 
 erately rapid plates this may he managed without any great 
 trouble, loss of time or expense. The cameras, or other appa- 
 ratus for reduction, are arranged in the usual way for daylight 
 reduction, care being taken not to stop down the reducing 
 lens more than is absolutely necessary. Magnesium ribbon 
 will be found the most suitable radiant for this work. The 
 ground glass “ diffuser ” behind the negative may be used, in 
 which case the magnesium — of which several inches will be 
 required — is to be kept moving evenly all over the back of 
 the ground glass as near to it as convenient. But probably a 
 better way is to use a reflector such as a white sheet of blotting 
 or filter paper placed behind the negative and at a suitable 
 angle to it. Two pieces of magnesium ribbon, one on each 
 side of the reflector, may with advantage be used, and the 
 burning ribbon kept moving so as to illuminate all parts of 
 the reflector evenly, and care must be taken to guard the nega- 
 tive against direct light from the radiant. An “ illuminating 
 box,” such as lately suggested by Mr. T. X. Armstrong, may 
 be found useful but is not necessary. The light given off by 
 burning magnesium is of so actinic a character that the 
 exposure required is not by any means so long as might be 
 expected. 
 
 Combination Printing , e. g., of Clouds. A large expanse 
 of clear glass representing the sky over a landscape is by no 
 means an artistic or pleasing feature. Clouds may be printed 
 in on the following lines, but the operation requires consider 
 able skill, care and experience, and in the most accustomed 
 
LANTERN-SLIDES BY PHOTOGRAPHIC METHODS. 
 
 67 
 
 hands failure is not uncommon. Still the result often amply 
 repays the trouble. 
 
 1st. A cloud positive may be printed from a cloud negative 
 by contact or reduction and the positive used as cover glass for 
 the slide, the image-bearing film of the positive being, of 
 course, mounted next the face of the slide. To do this nicely 
 by contact the contour of the horizon of the positive landscape 
 should be traced on a piece of dark-colored paper and cut out, 
 the part of the mask representing the landscape being used as 
 a “vignetter” for the clouds. That is to say, a mask corre- 
 sponding to the landscape is to be held in front of the frame 
 and quickly moved up and down while the cloud exposure is 
 going on. By this method the sky-blue will blend nicely with 
 the landscape when the two glasses are mounted together. 
 We have found it impossible to cut away or dissolve off part 
 of a cloud positive so as to make it fit over a landscape 
 positive. If the cloud slide is to be made by reduction the 
 landscape mask must correspond with the landscape of the 
 large or original negative, and is to be moved slightly behind 
 the larger cloud negative during exposure. This is not at all 
 an easy process. If it is found that the clouds encroach on 
 the landscape when the two glasses are placed together, the 
 lower part of the clouds maybe “reduced” to the extent of 
 annihilation by potass, ferricyanide, or iron perchloride and 
 hypo. As these can be used with a brush the cloud sky-line 
 can be nicely graduated. 
 
 2d. Landscape and clouds on the same plate. If the land, 
 scape and cloud negatives are both of the same size, and if the 
 cloud negative can be placed exactly where the landscape 
 negative was during reduction, the difficulty in cases of reduc- 
 tion is not so great as might be expected. A print of the 
 landscape may be made on a sheet of spoilt albumen paper, 
 for instance, and only deeply enough printed to show the 
 horizon line. We then cut along this horizon line with scissors 
 and preserve the two pieces. While the landscape is printing 
 we use the sky mask as a vignetter, and when the cloud is 
 being printed we use the landscape mask as a vignetter. In 
 
68 
 
 LANTERN-SLIDES BY PHOTOGRAPHIC METHODS. 
 
 printing by contact there is no great trouble, and in reducing 
 it is better to use a larger reflector than a diffuser, for the hand 
 can get between reflector and negative to manipulate the 
 masks. As no image is seen we must take care to “ register ” 
 the positions of cloud and landscape negatives. In reducing, 
 our routine is as follows : Reduce the landscape, shading the 
 
 sky — if the negative sky is not dark enough — with the sky 
 mask ; shut the dark slide ; put cloud negative into the position 
 lately occupied by landscape negative; open the dark slide 
 and expose again, shading the landscape part of the slide by 
 moving the landscape mask in front of the cloud negative. 
 These are somewhat uncertain operations, but with care and 
 practice they will produce the desired effect. 
 
Table for Enlargement and Reduction. 
 
70 LANTERN-SLIDES BY PHOTOGRAPHIC METHODS. 
 
 8 
 
 o 
 
 P 
 
 P 
 
 W 
 
 H 
 
 » 
 
 W 
 
 8 
 
 w 
 
 0 
 
 <J 
 
 B 
 
 § 
 
 1 
 g 
 
 H 
 
 **4 
 
 SC 
 
 05 
 
 © ®* 
 Wo 
 
 156 
 
 6.2 
 
 182 
 
 7.3 
 208 
 
 8.3 
 
 234 
 
 9.4 
 
 260 
 
 10.4 
 
 286 
 
 11.4 
 
 312 
 
 12.5 
 
 338 
 
 13.5 
 
 364 
 
 14.6 
 
 390 
 
 15.6 
 
 ■d 
 
 05 
 
 125 
 
 5.2 
 
 O co 
 
 in® 
 
 175 
 
 7.3 
 200 
 
 8.3 
 
 225 
 
 9.4 
 
 250 
 
 10.4 
 
 275 
 
 11.5 
 
 300 
 
 12.5 
 
 325 
 
 13.5 
 350 
 
 14.6 
 
 375 
 
 15.6 
 
 Vk’ 
 
 CO 
 
 05 
 
 O ®* -rH «> 
 
 s®3® 
 
 168 
 
 7.3 
 192 
 
 8.3 
 
 216 
 
 9.4 
 
 240 
 
 10.4 
 
 264 
 
 11.5 
 
 288 
 
 12.5 
 
 312 
 
 13.6 
 
 336 
 
 14.6 
 
 o *> 
 «® d 
 
 CO T— t 
 
 ■d 
 
 SC c* 
 
 00 CO 
 
 T— 1 00 T* 
 
 }>• T* 
 
 o so 
 
 CO so 
 
 CD »0 
 
 C 5 co 05 CO 
 
 SO t- 
 
 05 
 
 nl *»’ 
 
 ®2d 
 
 <® sd <» ao' 
 
 ^os' 
 
 cod 
 
 so 
 
 i ~ d 
 
 CS d 05 d 
 
 ^ d 
 
 <M 
 
 
 1—1 
 
 rH 1— 1 
 
 Oi 
 
 05 rH 
 
 05 th 
 
 05 rH 
 
 05 TH CO *H 
 
 0J d 
 
 •d 
 
 o <?* 
 
 05 co co co n* 
 
 00 ^ 
 
 O so 
 
 05 »0 tH co 
 
 CD CO QO l> CD t- 
 
 yH 
 
 ' 1— ! so 
 
 Wo- 
 
 L 9 t- oo 
 
 ’Os aJ 
 
 £5 d 
 
 25 th* 
 
 c® d 
 
 GO d O d 
 
 CO iO 
 
 05 
 
 
 rl 
 
 tH rH 
 
 T-t 
 
 05 TH 
 
 05 TH 
 
 05 
 
 05 TH CO T-H 
 
 coS 
 
 vT 
 
 SC w 
 
 co CO 
 
 £— rf GO 'c* 
 
 O SO 
 
 O »0 
 
 t-H CO 
 
 05 CO 
 
 CO l> tr 
 
 SO ao 
 
 o 
 
 ^ so* 
 
 £*<© 
 
 ^ sd ® ao' 
 
 OOd 
 
 iri 
 
 CO rH 
 
 JO d 
 
 i>d 
 
 rH d 
 
 Oi 
 
 
 lH 
 
 rH rH 
 
 rH 
 
 05 rH 
 
 05 th 
 
 05 rH 
 
 05 th 05 S 
 
 CO d 
 
 vT 
 
 O co 
 
 O co 
 
 O 'H* O "H 1 
 
 O *o 
 
 o so 
 
 O co 
 
 0»0f*0t*0® 
 
 cs 
 
 o» 
 
 £2 co 
 
 23*d «® 00 
 
 S 2 os‘ 
 
 O d 
 
 05 rH 
 
 ^ d 
 
 co d GO d 
 
 o d 
 
 
 
 t— i 
 
 tH -i— i 
 
 rH 
 
 05 l=i 
 
 05 TH 
 
 05 Sh 
 
 05 S 05 lA 
 
 CO d 
 
 ' vT 
 
 SC CO 
 
 t^I CO 
 
 CO "HJ C 5 rf 
 
 rH *0 
 
 o CO 
 
 OS <0 
 
 00 t- 
 
 £- S> CD 00 
 
 SO ao 
 
 00 
 
 OS |Q 
 
 T ~! d 
 
 CO *0) oo 
 
 oi 
 
 os d 
 
 O rH 
 
 O? ®i 
 
 ^ d «® d 
 
 00 d 
 
 
 
 T— 1 
 
 th th 
 
 rH 
 
 rH th 
 
 05 TH 
 
 05 th 
 
 05 th 05 
 
 05 d 
 
 
 o « 
 
 OO'* 
 
 co "* ^ so 
 
 05 »0 
 
 o CO 
 
 QO«ocDC’ , ^aoc 5 ao 
 
 O os 
 
 i> 
 
 OS jq 
 
 Oo 
 
 2 * id 2 ! ao 
 
 =®os 
 
 00 o 
 
 CS rH 
 
 3 -n d 
 
 cpdiSd 
 
 i> d 
 
 T— • 
 
 
 1 — 1 
 
 rH rH 
 
 rH 
 
 rH th 
 
 rH rH 
 
 05 TH 
 
 C 5 d 05 d 
 
 05 d 
 
 V* 
 
 SC CO 
 
 05 h* 
 
 CS '* CD so 
 
 CO «o 
 
 O o 
 
 Tflt- 
 
 tH 00 GO OS 
 
 SC os 
 
 CO 
 
 QO«s 
 
 ®d 
 
 1-1 co oj 
 
 Wffl 
 
 i -'~ d 
 
 CO _■ 
 
 s®* 
 
 05 d ®p d 
 
 Wd 
 
 r-H 
 
 T— 1 
 
 rH rH 
 
 rH 
 
 rH th 
 
 rH th 
 
 05 TH 
 
 C5 th 05 th 
 
 05 t4 
 
 "d 
 
 o CO 
 
 05 '* 
 
 05 so 00 *« 
 
 «o 
 
 O *> 
 
 CD t- 
 
 C> 
 
 COOS THCS o.. 
 
 SC 
 
 tH 
 
 OOko' 
 
 Oc) 
 
 rH jJ O? qo" 
 
 rH rH 
 
 
 Ss 
 
 t- rH 
 rH th 
 
 S2 
 
 Od £5 d 
 
 05 th 05 t-h 
 
 
 *d 
 
 to ^ 
 
 o ^ 
 
 SC so O c© 
 
 IO «=> 
 
 O t- 
 
 IO co 
 
 o OS 
 
 SO os o _ 
 
 SC rH 
 
 T— 1 
 
 JO 
 
 
 
 Wes' 
 
 «o 
 
 TH rH 
 
 C® rH 
 rH rH 
 
 GO®** 
 
 rH th 
 
 2«sS 
 
 rH th 05 
 
 d 
 
 05 TH 
 
 •Kk* 
 
 o ^ 
 
 •* 
 
 00 SO CQ O 
 
 co t- 
 
 o CO 
 
 Htf 00 
 
 00 0 > 
 
 05^. CO t-h 
 
 o ®* 
 
 CO 
 
 tH 
 
 i^O 
 
 OO d 
 
 id rH QO* 
 
 05 os' 
 
 
 SO rH* 
 
 T-H rH 
 
 Ss 
 
 S-Ss 
 
 rl co 
 
 05 TH 
 
 *** 
 
 SC '* 
 
 00 10 
 
 co ^ t- 
 
 CO 
 
 o CO 
 
 CO OS 
 
 C® ro 
 
 CS H«« 
 
 sc « 
 
 t-H 
 
 <K>so* 
 
 *>d 
 
 Q> t> o 00 
 
 S® 
 
 CO d 
 
 ^ th’ 
 rH i-h 
 
 so £2 
 
 T— 1 
 
 5® d GO so 
 
 1—i i-» 
 
 
 o ^ 
 
 
 O CO 
 
 00 ao 
 
 O 05 
 
 05 „ 
 
 TT^rH 
 
 CD 05 00 «3 
 
 O ■d* 
 
 t-H 
 
 tH 
 
 
 *>d 
 
 00 tJ os 00 
 
 S-* 
 
 Ss 
 
 CO®* 
 
 21 d 
 
 rH r-i 
 
 *® d «® is 
 
 tHh tHh 
 
 GOd 
 
 rH th 
 
 is> 
 
 SC so 
 
 co 
 
 i>. t- 00 CD 
 
 Cs <=s # 
 
 o _ 
 
 rH t-h 
 
 05 ®* 
 
 CO co hj« 
 
 SC *0 
 
 O 
 
 rH 
 
 Okfl' 
 
 ®«> 
 
 £— 1> OO qo 
 
 Cs 
 
 th rj 
 tH 
 
 05 d 
 
 00 eo 
 
 ^d *® d 
 
 rH T-H rH -rH 
 
 CDd 
 
 rH th 
 
 
 o 50 
 
 OJ> 
 
 O co o co 
 
 O °s. 
 
 O TH 
 
 O ®* 
 
 O C0 
 
 o-^oo 
 
 O i> 
 
 os 
 
 *Ott 
 
 CO d 
 
 i-— f" OO qo 
 
 CS oi 
 
 O T _- 
 
 T — 1 TH 
 
 rH d 
 
 rH th 
 
 £*d 
 
 rH th 
 
 CO d 
 
 riH tHh 
 
 so d 
 
 rH th 
 
 
 SC 1:0 
 
 •tH ao 
 
 CO <=s C5 
 
 rH i-h 
 
 O co 
 
 CS Ht< 
 
 00 »0 
 
 £- CO CD 00 
 
 SC os 
 
 00 
 
 o' 
 
 U 3 t © 
 
 CD L J i>® 
 
 GOd 
 
 TH 
 
 CS rH 
 
 ®s d 
 
 Ss 
 
 ^ d ®* >0* 
 
 CO d 
 
 TH tH 
 
 
 O i- 
 
 00 os 
 
 CD„ TH 
 
 C5 C0 
 
 o ^ 
 
 00 co 
 
 CD *> -rts os c 5 _ 
 
 © rH 
 
 t- 
 
 ^o 
 
 TT 1 d 
 
 O® CD 0 - 
 
 £- o' 
 
 TH 
 
 00 rH 
 
 00 d 
 
 CS so 
 
 Od ild 
 
 rl th r 1 
 
 05 d 
 
 rH th 
 
 
 SC 00 
 
 05 J. 
 
 Oi C* CD CO 
 
 CO *0 
 
 o t- 
 
 £-00 
 
 rti „ 
 
 tH rH GO CO 
 
 SC »0 
 
 o 
 
 Mw 
 
 th*" 
 
 ^ 00 JO os' 
 
 ®o 
 
 L- rH 
 TH 
 
 d 
 
 rH 
 
 00^1 
 
 CS d CS d 
 
 TH TH 
 
 Sd 
 
 
 o p _ 
 
 co ®* 
 
 C?^ OO'O 
 
 00 
 
 o „ 
 
 co ®* 
 
 05 ^ 
 
 00 o co 
 
 
 sc 
 
 CO® 
 
 co^ 
 
 ^ 00 ^ OS 
 
 *Oo 
 
 CO®* 
 
 cod 
 
 i-'-d 
 
 rH 
 
 t- d GO CD 
 
 H t— • 
 
 0*0 o® O- 10 « 0*0 io® o - >o« o« o® 
 
 C5 co 00 CO QO ^*S W«©J3 <© d i" d d 
 
 ©fr-^_<»eoC5<.-©„©eo^!>cO,-05mcO*>:© 0 
 
 C5 d 05 00 05 OS COo'COS^ed^nJ^S Wt- *® ao «© §i 
 
 TH 1-1 1-1 TH T-H 
 
 W^OOhsTHSOh^., £~»0©„e©‘®CD-.«5‘005_ 1 5O»O 
 HiJ r-i ® 05 d «”.«« CO £ CO co CO ^ CO os ^ ^ g| 
 
 •suaq am josno 
 -o_j juaiEAinbg 
 
 
 
LAN TEEN- SLIDES BY PHOTOGRAPHIC METHODS. 
 
 71 
 
 416 
 
 16.6 
 
 442 
 
 17.7 
 
 468 
 
 18.7 
 494 
 
 19.8 
 
 520 
 
 20.8 
 
 546 
 
 21.8 
 
 03 tH 
 
 £r ci 
 IO Ci 
 
 598 
 
 23.9 
 
 624 
 
 25 
 
 650 
 
 26 
 
 400 
 
 16.7 
 
 425 
 
 17.7 
 
 450 
 
 18.8 
 
 475 
 
 19.8 
 
 500 
 
 20.8 
 
 525 
 
 21.9 
 
 550 
 
 22.9 
 
 1575 
 
 24 
 
 600 
 
 25 
 
 625 
 
 26 
 
 384 
 
 16.7 
 
 408 
 
 17.7 
 
 432 
 
 18.8 
 
 456 
 
 19.8 
 
 480 
 
 20.9 
 
 504 
 
 21.9 
 
 00 „ 
 g^ 
 
 552 
 
 24 
 
 576 
 
 25 
 
 600 
 
 26.1 
 
 368 
 
 16.7 
 
 391 
 
 17.8 
 414 
 
 18.8 
 
 437 
 
 19.8 
 
 460 
 
 20.9 
 
 CO <3> 
 00 
 
 ^ ci 
 
 506 
 
 23 
 
 o 
 
 g^ 
 
 552 
 
 25.1 
 
 575 
 
 26.1 
 
 352 
 
 16.8 
 
 ^ oo 
 CO i-i 
 
 396 
 
 18.8 
 
 oo 
 
 3a 
 
 440 
 
 21 
 
 1*38 
 
 506 
 
 24.1 
 
 528 
 
 25.1 
 
 550 
 
 26.2 
 
 336 
 
 16.8 
 
 357 
 
 17.9 
 
 378 
 
 18.9 
 
 399 
 
 20 
 
 420 
 
 21 
 
 441 
 
 22.1 
 
 462 
 
 23.1 
 
 483 
 
 24.2 
 
 504 
 
 25.2 
 
 525 
 
 26.3 
 
 320 
 
 16.8 
 
 340 
 
 17.9 
 360 
 
 18.9 
 
 380 
 
 20 
 
 400 
 
 21.1 
 
 420 
 
 22.1 
 
 440 
 
 23.2 
 
 460 
 
 24.2 
 
 480 
 
 25.3 
 
 500 
 
 26.3 
 
 [304 
 
 16.9 
 
 323 
 
 17.9 
 
 342 
 
 19 
 
 361 
 
 20.1 
 
 380 
 
 21.2 
 
 399 
 
 22.2 
 
 418 
 
 23.2 
 
 437 
 
 24.3 
 
 456 
 
 25.3 
 
 475 | 
 
 26.4 
 
 288 
 
 16.9 
 
 o® 
 
 00 
 
 324 
 
 19.1 
 
 342 
 
 20.1 
 
 360 
 
 21.2 
 
 378 
 
 22.2 
 
 CO ©3 CO 
 
 05 §5 
 
 432 
 
 25.4 
 
 450 
 
 26.5 
 
 272 
 
 16.9 
 
 289 
 
 18.1 
 
 306 
 
 19.1 
 
 CO Ci 
 
 2*0 
 CO cj 
 
 340 
 
 21.3 
 
 357 
 
 22.3 
 374 
 
 23.4 
 
 391 
 
 24.4 
 
 408 
 
 25.5 
 
 425 
 
 26.6 
 
 40 TH 
 
 St 
 
 272 
 
 18.1 
 
 288 
 
 19.2 
 
 304 
 
 20.3 
 320 
 
 21.3 
 
 336 
 
 22.4 
 
 352 
 
 23.5 
 
 368 
 
 24.5 
 
 384 
 
 25.6 
 
 400 
 26.7 ^ 
 
 © 
 
 03 H 
 
 255 
 
 18.2 
 
 270 
 
 19.3 
 285 
 
 20.4 
 
 300 
 
 21.4 
 
 315 
 
 22.5 
 
 330 
 
 23.6 
 
 130 
 
 CO & 
 
 360 
 
 25.7 
 
 375 
 
 26.8 
 
 ■TH Ci 
 t- 
 C3 ,-i 
 
 238 
 
 18.3 
 
 252 
 
 19.4 
 
 266 
 
 20.5 
 
 280 
 
 21.5 
 
 294 
 
 22.6 
 
 308 
 
 23.7 
 
 322 
 
 24.8 
 
 336 
 
 25.8 
 
 350 
 
 26.9 
 
 COCO 
 
 o t : 
 
 03 U 
 
 221 
 
 18.4 
 
 234 
 
 19.5 
 
 ' 247 
 20.6 
 
 260 
 
 21.7 
 
 273 
 
 22.8 
 
 286 
 
 23.8 
 
 299 
 
 24.9 1 
 312 
 26 
 
 325 
 
 27.1 
 
 192 
 
 17.5 
 
 204 
 
 18.5 
 216 
 
 19.6 
 
 CO 
 
 C3 d 
 
 240 
 
 21.8 
 
 03 ■=» 
 
 »o d co 35 
 03 cl Ol®* 
 
 276 
 
 25.1 
 
 00 ©* 
 ggd 
 
 03 Ci 
 
 300 
 
 27.3 
 
 176 
 
 17.6 
 
 187 
 
 18.7 
 
 198 
 
 19.8 
 209 
 
 20.9 
 
 «g| 
 
 03 04 
 
 231 
 
 23.1 
 
 242 
 
 24.2 
 
 253 
 
 25.3 
 
 264 
 
 26.4 
 
 275 
 
 27.5 
 
 160 
 
 17.8 
 
 170 
 
 18.9 
 
 |g 
 
 190 
 
 21.1 
 
 o ©i 
 
 210 
 
 23.3 
 
 220 
 
 24.4 
 
 230 
 
 25.6 
 
 240 
 
 26.7 
 
 250 
 
 27.8 
 
 1—1 
 
 CO 
 
 3 S 
 
 03 co 
 
 <-> o' 
 
 T-1 S3 
 
 -r-3 ^ 
 i - _• 
 TH Ci 
 
 O 
 
 CO ri 
 T-t Ci 
 
 189 
 
 23.7 
 
 198 
 
 24.8 
 
 207 
 
 25.9 
 
 216 
 
 27 
 
 225 
 
 28.1 
 
 128 
 
 18.3 
 
 136 
 
 19.4 
 
 ^ o 
 
 2d 
 
 T-t C3 
 
 152 
 
 21.7 
 
 160 
 
 22.9 
 
 168 
 
 24 
 
 176 
 
 25.1 
 
 184 
 
 26.3 
 
 192 
 
 27.4 
 
 200 
 
 28.6 
 
 112 
 
 18.7 
 
 119 
 
 19.8 
 
 CO 
 
 o? 55 
 
 133 
 
 22.2 
 
 140 
 
 23.3 
 
 I> iO 
 
 ^ S 
 
 T-t Ci 
 
 154 
 
 25.7 
 
 161 
 
 26.7 
 
 goo 
 
 175 
 
 29.2 
 
 96 
 
 19.2 
 
 102 
 
 20.4 
 
 108 
 
 21.6 
 
 114 
 
 22.8 
 
 o 
 
 126 
 
 25.2 
 
 132 
 
 26.4 
 
 138 
 
 27.6 
 
 144 
 
 28.8 
 
 150 
 
 30 
 
 80 
 
 20 
 
 85 
 
 21.3 
 
 90 
 
 22.5 
 
 ! 95 
 
 23.8 
 
 100 
 
 25 
 
 105 
 
 26.3 
 
 O 
 
 TH 
 
 115 
 
 28.8 
 
 gs 
 
 125 
 
 31.3 
 
 64 
 
 21.3 
 
 68 
 
 22.7 
 
 72 
 
 24 
 
 76 
 
 25.3 
 
 80 
 
 26.6 
 
 84 
 
 28 
 
 88 
 
 29.3 
 
 I 92 
 30.7 
 
 csg 
 
 is 
 
 481 
 
 24 
 
 1— ( *0 
 CM 
 
 54 
 
 27 
 
 57 
 
 28.5 
 
 08 
 
 09 
 
 co w 
 
 50 d 
 CO 
 
 66 
 
 33 
 
 69 
 
 34.5 
 
 72 
 
 36 
 
 75 
 
 37.5 
 
 03 „ 
 
 cog 
 
 34 
 
 34 
 
 cOro 
 
 38 
 
 38 
 
 40 
 
 40 
 
 
 44 
 
 44 
 
 46 
 
 46 
 
 48 
 
 48 
 
 1 50 
 60 
 
 CO 
 
 fH 
 
 rH 
 
 00 
 
 tH 
 
 19.. 
 
 0 
 
 01 
 
 tH 
 
 03* 
 
 03 
 
 co 
 
 03 
 
 Ttt 
 
 03 
 
 30 
 
 03 
 
 3 
 
 JS 
 
 Ja 
 
 d 
 
 •Th 
 
 o 
 
 
 £ 
 
 tu 
 
 <u 
 
 (A 
 
 A 
 
 o 
 
 <D 
 
 a 
 
 <L> 
 
 U 
 
 hS § 
 
 <U 43 
 
 I o 
 
 ns r* 
 
 rC 
 
 t n 
 
 a 
 
 o 
 
 03 
 
 S 
 
 o 
 
 C/3 
 
 43 
 
 JS 
 
 O 
 
 G 
 
 C/3 
 
 J-l 
 
 43 
 
 II 
 
 The table can be formulated thus : Where 1> — focal length of lens, a = distance from ground-glass to centre of lens and 
 

 
 
 
 
INDEX. 
 
 PAGE. 
 
 Acetate Toner Collodio-Chlo- 
 
 ride 59 
 
 Acidity of Silver Bath 24 
 
 Albumen Preservative 30 
 
 Albumen Process 6 
 
 Albumenizing Glass 32 
 
 Alum, use of with Gelatine.. . . 40 
 
 Alum and Acid Solution 51 
 
 Alum Before Fixing Gelatine 
 
 Bromide 51 
 
 Amber Varnish 29 
 
 Ammonium Sulpho-Cyanide 
 
 Toner 58 
 
 Aperture of Reducing Lens . . 19 
 
 Aperture of Masks 64 
 
 Apparatus for Reduction 16 
 
 Apparatus Required 14 
 
 Argentic Stain, Henderson's... 57 
 Argentic Stain for Shadows... 11 
 
 Argentometer 25 
 
 Armstrong, His Palladium 
 
 Toner 29 
 
 Armstrong’s Illuminating Box. 66 
 
 Art Considerations 8 
 
 Artificial Light, Reduction by. 66 
 Author’s Reducing Camera. .. . 18 
 
 Beau Ideal Slid es 5 
 
 Beer and Pyro Preservative. . . 33 
 
 Beer Preservative 30 
 
 Best All-round Process, Gela- 
 tine Bromide 13 
 
 Bolton, W. B., His Dry Collo- 
 dion Emulsion 31 
 
 Bolton, W. B., On Gelatines... 39 
 Brooks, Wm., His Developers. 34 
 
 Cameras for Copying 16 
 
 Cam* ra Reduction 16 
 
 Candle Standard for Exposure. 14 
 Carbutt’s Developers, Gelatine 
 
 Bromide 49 
 
 Centrifugal Separation 41 
 
 Character of Wet Collodion. . . 11 
 
 Characteristics of Processes 
 
 11 et seq. 
 
 Chloride Emulsion, Gelatine. . 54 
 
 Chloride in Gelatine Bromide. 40 
 Cleaning Glass for Wet Collo- 
 dion 22 
 
 PAGE. 
 
 “ Clear ” Slides and the Public 9 
 
 Clearing Gelatine Plates 51 
 
 Clearing Solutions, Gelatine 
 
 Plates 51 
 
 Clouds, To Print in. 66 
 
 Coating Plates with Gelatine. . 44 
 
 Coating with Collodion Emul- 
 sion 33 
 
 Coffee Preservative for Dry 
 
 Collodion 30 
 
 Collodio-Chloride 59 
 
 Collodion, Iodized 22 
 
 Collodion Dry Bath Plates. ... 30 
 
 Collodion Emulsion . . . .31 et seq. 
 Collodion Films Slipping .... 38 
 
 Collodionizing the Plate 22 
 
 Color or Tone of Slides 9 
 
 Coloring, Treatment of Slide 
 
 for 60 
 
 Coloring Lantern Slides 60 
 
 Coloring Slides, Requisite Ma- 
 terials 61 
 
 Colors Suitable for Painting 
 
 Slides 61 
 
 Combination Printing of 
 
 Clouds 66 
 
 Contact Printing, Apparatus.. 14 
 Contact Printing, Distance.... 15 
 Contact Printing, Radiants for. 14 
 
 Copying Engravings 53 
 
 Cowan, A., His Gelatine Chlo- 
 ride Emulsion 54 
 
 Cowan, A., His Plate Cutter. . 44 
 
 Cowan A., His Reducing Pro- 
 cess 52 
 
 Cowan, Mr. A., His Slides. ... 19 
 
 Cowan’s Developers for Gela- 
 tine Chloride 55 
 
 Dallinger, Dr., His Designs on 
 
 Slides 63 
 
 Dallmeyer’s Lens for Reducing 19 
 Damp Attacking Mounted 
 
 Slides 53 
 
 Dark Slide in Wet Process. ... 23 
 
 Dark-room Lanterns 15 
 
 Deposite in Slide, Nature of... 7 
 
 Description of Good Slide. ... 7 
 
 Developer, Ferrous Oxalate. . . 45 
 
 Developer, Pyro for Wet Plates 26 
 
INDEX. 
 
 PAGE. 
 
 Developer, Pyro-Meta-Bisul- 
 
 phite 47 
 
 Developer, Quinol Caustic. ... 45 
 
 Developers lor various tones, 
 
 gelatine bromide 45 et seq. 
 
 Developers for Gelatine Chlo- 
 ride Plates 55 
 
 Developing Wet Plates 25 
 
 Development, Manipulations of 50 
 Development of Dry Collodion 34 
 Dipping Bath, Wet Process. . . 23 
 
 Distance for Contact Printing. 15 
 Dry Bath Collodion Plates.... 30 
 
 Dry Collodion 30 
 
 Dry Collodion, Intensification . 37 
 
 Dry Collodion, Organifiers . . . . 30 
 
 Dry Collodion Plates, Devel- 
 oping 34 
 
 Dry Collodion Plates, Fixing.. 37 
 Dry Collodion Plates, To Tone 33 
 Drying Gelatine Plates, Coated 44 
 Drying Collodion Plates 28 
 
 Eastman Co. Tran sfero type .. . 58 
 
 Edging Plates for Collodion 
 
 Emulsion 33 
 
 Edwards, B J., Developer for 
 Gelatine Chloride Plates. . . 55 
 
 Edwards, B. J., Quinol Devel- 
 oper ... 45 
 
 Edwards’ Clearing Solution... 51 
 Emulsifying Gelatine Emul- 
 sion 41 
 
 Emulsion, Collodion Washed. 33 
 
 Emulsion, Dry Collodion 31 
 
 Emulsion, Gelatine Bromo- 
 
 Chloride 40-41 
 
 Emulsion, Gelatine Bromo- 
 
 Iodide 40 
 
 Emulsion, Unwashed Collo- 
 dion . . 31 
 
 Emulsion, Washed Collodion . 33 
 
 Engraving Black Tones on 
 
 Collodion 38 
 
 Engravings. Copying and Mak- 
 ing Slides 53 
 
 Enlargement and Reduction 
 
 Tables 69 
 
 Essentials for Perfect Slide 
 
 7 et seq. 
 
 Exposure, Relation to Develop- 
 ment 49 
 
 Exposure of Gelatine Bromide 
 
 Plates 45 
 
 Exposure of Gelatine Bromide, 
 Results of 45 
 
 PAGE. 
 
 Farmer, Howard,’ His Reducer 52 
 Ferricyanide Reducing Process 52 
 
 Ferrier. His Slides 6 
 
 Ferro-Citro-Oxalate Developer 49 
 Ferrous O palate Developer. . . 45 
 
 Filtering Collodion Emulsion. 32 
 Filtering Gelatine Emulsion. . . 43 
 
 Fixing Dry Collodion Plates.. 37 
 Fixing Gelatine Bromide 
 
 Plates 51 
 
 Fixing Wet Plates 28 
 
 Fog, Red, in Gelatine Emulsion 42 
 
 Gas Burner for Contact Print- 
 ing 14 
 
 Gelatine Bromide, All-round 
 
 Process 13 
 
 Gelatine Bromide, Conven- 
 ience of 39 
 
 Gelatine Bromide Emulsion. . . 39 
 
 Gelatine Bromide Plates, Ex- 
 posure 45 
 
 Gelatine Bromo-chloride Emul- 
 sion 40 
 
 Gelatine Bromo-iodide Emul- 
 sion 40 
 
 Gelatine Chloride Emulsion. . . 54 
 
 Gelatine Chloride Plates, Ex- 
 posure for 55 
 
 Gelatine Chloride Plates, Qual- 
 ities of 12 
 
 Gelatine Chloride Plates, Re- 
 duction 56 
 
 Gelatine Emulsion, Alcohol 
 
 Treatment 43 
 
 Gelatine Emulsion, Coating the 
 
 Plates 44 
 
 Glass, To Albumenize 32 
 
 Glass, To Write on 63 
 
 Glass for Wet Process, Size of 22 
 
 Gold for Toning Collodion 
 
 Plates 29 
 
 Good Slide, Description of. . . . 7 
 
 Gradation in Slides 8 
 
 Ground Glass for Reduction. . . 17 
 
 Ground Glass for Slide Camera 20 
 
 Gummed Strips 64-85 
 
 Heinrich’s Gelatine 42 
 
 Henderson, A. L., His Emul- 
 sion Washer 43 
 
 Henderson’s A. L., Argentic 
 
 Stain. ... 57 
 
 Hydroquinone Caustic Devel- 
 oper 45 
 
 1 Hypo, for Wet Plates 28 
 
INDEX. 
 
 Inklsketch on Plain Glass. ... 63 
 
 Intensification of Wet Plates . . 28 
 
 Intensifying Dry Collodion.. . . 37 
 
 Interiors, Slides of 9 
 
 Introduction 5 
 
 Iron Developer, Wet Plates.. . . 27 
 
 Lanterns, Non-actinic 15 
 
 Lantern, Transferotype Slides 
 
 in the 59 
 
 Lens for Reducing, Aperture of 19 
 Lens for Reducing, Focus of . . 19 
 
 Lenses for Reducing 19 
 
 Level Slab for Gelatine Plate . . 44 
 
 Line Subjects, Engravings, To 
 Copy. 53 
 
 Magnesium Light for Reducing 66 
 Magnesium Ribbon for Expos- 
 ure 15 
 
 Magnesium Ribbon Spoiled by 
 
 Keeping 15 
 
 Marking Mounted Slides 65 
 
 Masks, To Make at Home .... 64 
 
 Mask for Contact Printing 14 
 
 Masks for Slides 10 
 
 Masks for Slides. 64 
 
 Mawson & Swan, Pyro Devel- 
 oper 47 
 
 Mounting, Operation of 65 
 
 Mounting Slides 64-65 
 
 Negatives from Line Subjects.. 53 
 Nelson’s Gelatine for Emul- 
 sion 39 
 
 Nested Carriers for Negatives. 17 
 
 Ocular or Eye Piece for Focus- 
 ing 20 
 
 Oil Lamp for Exposure 14 
 
 Organifiers, Dry Collodion .... 30 
 
 Process, Woodbury’s 5 
 
 Process, Albumen 6 
 
 Printing Frames Required 14 
 
 Process, Wet Collodion 21 et seq. 
 
 “ Pinholes” Due to Silver Bath 24 
 Pinholes, Cause of, in Wet 
 
 Process 24 
 
 Pyrogallol, Developer Wet 
 
 Plate 26 
 
 Potass, Cyanide for Wet Plates 28 
 Platinum Toner for Wet Plates 28 
 Preservatives, Dry Collodion . . 30 
 
 Pyroxyline for Emulsion .... 31 
 
 Pellicle, Collodion Emulsion. . 34 
 
 Precipitation of Gelatine by 
 
 Alcohol 43 
 
 Packing Gelatine Plates 44 
 
 Preservation of Gelatine Emul- 
 sion Plates 44 
 
 Potass, Meta-bisulphite 47 
 
 Pyro Solutions for Develop- 
 ment 47 
 
 Pyro Ammonia Developer. ... 47 
 
 Pyro and Ammonia Carbonate. 
 
 Developer 48 
 
 Printing-Out Slide Process, A . 57 
 
 Paper (Transferotype) Slides. . . 58 
 
 Paper Strips, System Bad 65 
 
 Printing-Out Process on Collo- 
 dion 59 
 
 Printing in Clouds 66 
 
 Palladium Toner for Wet 
 Plates 29 
 
 Quantities of Good Slides. .7 et seq. 
 
 Quinol Caustic Developer 45 
 
 Quinol-Carbonate Developer. . 45 
 
 Ramsden Ocular, To Focus ... 20 
 
 Re-Development of Wet Plates 27 
 Red Fog in Gelatine Emulsion. 42 
 Reducing Camera, Author’s... 18 
 Reducing Camera Described.. . 16 
 
 Reducing Density by Iron 
 
 Chloride, Etc 52 
 
 Reduction, Requisites for 16 
 
 Reduction and Enlargement 
 
 Tables 69 
 
 Reduction in Camera 16 
 
 Reduction of Density, Gelatine 
 
 Plates 52 
 
 Reflector, Angle for Reduction 17 
 
 Reflectors for Reduction 17 
 
 Regulator Gas Burner 14 
 
 Requisites for Reduction .... . 16 
 
 Robinson’s Trimmer 64 
 
 Sandarac and Mastic Varnish. . 29 
 
 Scale of Gradation 11 
 
 Scale of Light 8 
 
 Scientific Slides, Tone for 10 
 
 Scum on Gelatine Plates 50 
 
 Sensitizing Wet Plates 24 
 
 Silver Bath, Acid 24 
 
 Silver Bath, diseases of 24 
 
 Silver Bath, To Iodize 23 
 
 Silver Bath, Wet Plate 23 
 
 Size, Convenient for Negatives 12 
 Size of Slide 10 
 
INDEX. 
 
 PAGE, 
 
 Sketching or Writing on Plain 
 
 Glass 68 
 
 Sky Negatives, To Print in. . . . 66 
 
 Slides of Line Subjects 53 
 
 Slides to Mark for the Lantern. 65 
 Slipping of Collodion Films... 38 
 Stand for Reducing Camera. . . 19 
 
 Strips, Gummed 64 
 
 Substratum for Collodion 
 
 Emulsion 33 
 
 Sulphur Toning Wet Plates ... . 29 
 
 Swansdown Calico for Filtering 43 
 
 Tables for Reduction 69 
 
 Tannin Preservative 30 
 
 Tap Water, Effect of on Certain 
 
 Plates 50 
 
 Thomas & Co., Pyro Developer 48 
 Tints for Coloring to be Trans- 
 parent 60 
 
 Toning Dry Collodion Plates. . 38 
 
 Toning Wet Plates 28 
 
 Toning Argentic Stain 58 
 
 Transferotype 58 
 
 PAGE, 
 
 Unwashed Collodion Emul- 
 sion 31 
 
 Varnish for Gelatine Slides. ... 5$ 
 
 Varnish for Wet Plates 29 
 
 Warm Tones 9, 12 
 
 Washing Collodion Emulsion . 34 
 
 Washing Gelatine Emulsion. . . 42 
 
 Wet Collodion, Character of. . 11 
 
 Wet Collodion, Qualities and 
 
 Dangers 21 
 
 Wet Process, Exposure 25 
 
 Wilson, G. W., His Glue for 
 
 Strips 65 
 
 Woodbury Type 5 
 
 York, Mr. F., His Sulphur 
 
 Toner 29 
 
 York’s Varnish for Collodion 
 Plates 29 
 
 Zinc Bromide, Purity of 31 
 
44 
 
 Sunlight and... 
 
 Shadow 
 
 A Book for Photographers, 
 
 AMATEUR and PROFESSIONAL. 
 
 ft 
 
 By W. X. LINCOLN ADAMS. 
 
 Containing Chapters and Illustrations by such well-known photographic writers and 
 
 workers as 
 
 H. P. ROBINSON, ALFRED STIEGLITZ, 
 
 A. HORSLEY HINTON, R. EICKEMEYER, Jr., 
 
 W. B. POST, J. WELLS CHAMPNEY, 
 
 B. J. FALK, ALEXANDER BLACK, 
 
 W. A. FRASER, 
 
 HER GRACE THE DUCHESS OF SERMONETA, 
 and the MARQUIS DE ALFARRAS. 
 
 It covers the field entirely, as shown by the fallowing 
 
 (^! CONTENTS 147 ) 
 
 THB CHOICE OF SUBJECT 
 LANDSCAPE WITHOUT FIGURES 
 LANDSCAPE WITH FIGURES 
 FOREGROUNDS 
 THE SKY 
 
 OUT-DOOR PORTRAITS and GROUPS 
 THE HAND CAMERA 
 
 INSTANTANEOUS PHOTOGRAPHY 
 WINTER PHOTOGRAPHY 
 MARINES 
 
 PHOTOGRAPHY AT NIGHT 
 LIGHTING IN PORTRAITURE 
 PHOTOGRAPHING CHILDREN 
 ART IN GROUPING 
 
 About 150 pages of the most instructive and entertaining reading matter, 
 
 .... and .... 
 
 More than lOO Beautiful Photo-Engravings, 
 
 MANY OF THEH FULL PAGE PICTURES. 
 
 Printed on Heavy Wood-cut Paper, with liberal margins and gilt edges. 
 Beautifully and Substantially bound in Art Canvas, with Gilt Design. 
 
 PRICE, IN A BOX, $2.50 
 
 Sent post free by mail, to any address, on receipt of amount by 
 
 THE SCOVILL & ADAMS COMPANY OF NEW YORK 
 
 60 and 62 East Eleventh Street, New York City. 
 
ILLUSTRATIONS IN - 
 
 Sunlight and Shadow. 
 
 In Prospect Park (Brooklyn). .W. I. Lincoln Adams. 
 
 By the River A. L. Eidemiller. 
 
 Morning Mist H. P. Robinson. 
 
 Day’s Decline A. Horsley Hinton. 
 
 Winter W. H. Dodge. 
 
 The Jungfrau Dr. J. Meiner. 
 
 On Lewes Creek H. Troth. 
 
 Woods P. Dementjeff. 
 
 By the Stream E. B. Garrison. 
 
 The Jungfrau Alfred Stieglitz. 
 
 In the Highlands W. Dawes. 
 
 Landscape and Clouds Arthur Burchett. 
 
 Shades of Evening 
 
 Her Grace the Duchess of Sermoneta. 
 
 Returning from Market Alfred Stieglitz. 
 
 An English Country Scene.. .Seymour Conway. 
 
 Study of Fisherfolk Miss K. G. Spink 
 
 A Sicilian Idyll Count Von Gloeden. 
 
 Mending Nets (Katwyk) ... . Alfred Stieglitz. 
 
 Here Comes Father Jesse Poundstone. 
 
 A Wet Day on Boulevard Alfred Stieglitz. 
 
 Foregrounds — Fig. 1 H. P. Robinson. 
 
 Fig. 2 
 
 Fig. 3 
 
 Fig. 4 
 
 Fig. 5 
 
 Fig. 6 
 
 The Sky— Fig. 1 
 
 Fig. 2 
 
 Fig. 3 
 
 Fig. 4 
 
 Fig. 5 
 
 Fig. 6 
 
 Hilltop Farm W. I. Lincoln Adams. 
 
 A Gutach Meeting Alfred Stieglitz. 
 
 Intimate Friends Mabel Osgood Wright. 
 
 An Alpine Cross Alex. Keighley. 
 
 As She Comes Down the 
 
 Stairs R. Eickemeyer, Jr. 
 
 “What is Your Fortune, My 
 
 Pretty Maid . Major R. H. Brown, 
 
 “ Nobody Axed You, Sir,” 
 
 she said “ “ “ 
 
 The Shepherd H. K Noyes. 
 
 “He Cometh Not,” she said..R. Eickemeyer, Jr. 
 
 A Favorite Occupation, 
 
 Venice Alfred Stieglitz. 
 
 Winter, Fifth Avenue 
 
 A Blockade, New York. . . . 
 
 Wash-day, Venice 
 
 A Hot Day 
 
 In the Fields 
 
 A Bit Near Munich 
 
 A Venetian Well 
 
 A Venetian Bit 
 
 Venetian Characters Alfred Stieglitz. 
 
 Katwyk Beach “ 
 
 Mid-ocean “ 
 
 The Diver Louis Meld on. 
 
 Throwing the Hammer 
 
 A Rise in the World The Marquis de Alfarras. 
 
 The Start James Burton. 
 
 Jumping 
 
 A Snap Shot C. C. Langill. 
 
 A Reminiscence of Winter. . . W. I. Lincoln Adams. 
 
 Under the Willows, “ “ 
 
 A Country Lane in Winter. ..A. R. Dresser. 
 
 End of a Winter's Day W. B. Post. 
 
 Frost Laden Randall Spaulding. 
 
 Boston Public Garden Newton W. Elwell. 
 
 A Winter Morning in Brookline 
 
 A Rough Morning Frank Hurndall. 
 
 Holy Loch H. P. Robinson. 
 
 Mr. Gould’s “Atlanta” 
 
 Valkyrie III, Ailsa, Britannia 
 
 Sky and Sea 
 
 Seagulls 
 
 On the Heatherbell 
 
 Marine Study J. M. Bemis. 
 
 Twilight, Mid-ocean T. Frank Atkinson. 
 
 The Sea Harry Platt. 
 
 By Bryant Park after the 
 
 Storm W. A. Fraser. 
 
 The Savoy Hotel, New York 
 
 —Stormy Night 
 
 Entrance to Central Park 
 
 The Giant Hotels, from Cen- 
 tral Park “ 
 
 Moonlight, Central Park 
 
 Study (from Recollections in 
 
 a Mirror) J. Wells Champney. 
 
 Portrait Studies 
 
 Isabel B. J. Falk. 
 
 Minnie 
 
 Rosita 
 
 Rita 
 
 Little Tuesday 
 
 Childhood 
 
 Child Study 
 
 Reflections 
 
 Child Study Fred. Boissonas. 
 
 Art in Grouping — No. 1 
 
 No. 2 
 
 “ No. 3 
 
 “ No. 4 
 
 “ No. 5 
 
 “ No. 6. 
 
 Scene from “A Capital 
 
 Courtship” Alexander Black. 
 
 M Beautiful Gift Book Tor the holidays. 
 
 For Sale by all dealers in Photographic Supplies, Booksellers, etc. 
 
 PRICE, POST FREE, IN A BOX, $2.50. 
 
“Amateur Pnotograpiiy.'' 
 
 : A : 
 
 Practical Guide for the Beginner. 
 
 by W. I. LINCOLN ADAMS, 
 
 ILLUSTRATED. 
 
 T HIS is a practical treatise for the beginner, by one whose 
 experience of, and immediate contact with, the needs 
 of those who are using the camera, in and out of doors, both 
 for pleasure and profit, especially fits him to help the 
 
 BEGINNER. 
 
 CONTENTS: 
 
 I. — Apparatus. II. — In the Field. III. — In the Dark-room. IV. — 
 Printing and Toning. V. — Portraiture. VI. — Instantaneous Photog- 
 raphy. VII. — Flash-light Photography. VIII. — Orthochromatic or 
 Color-sensitive Photography. IX. — Composite Photography. X. — 
 The “ Fathers of Photography.” Appendix, Tables, Formulas, Etc. 
 
 THE BOOK IS NOW IN ITS 
 
 FOURTH EDITION and FIFTH THOUSAND. 
 
 TOC/ CANNOT^ AFFORD to be without it. 
 
 For sale by all Dealers in Photographic Materials, Booksellers, etc., 
 or will be sent, post-paid, by mail to anv address, 
 
 In Paper Covers, on receipt of Fifty Cents. 
 
 In handsome Red Cloth Binding, with Qilt Lettering, $1.00, 
 
 BY 
 
 THE SCOVILL & ADAMS COMPANY OF NEW YORK, 
 
 60-62 EAST 11TH ST., ® ® NEW YORK CITY. 
 
 GET THE PERMANENT CLOTH BINDING . 
 
Carbutt Lantern Plates 
 
 The enormous increase in the sales of these 
 Plates proves beyond a doubt that they are 
 
 UNRIVALLED. . . 
 
 .... FOR .... 
 
 Making Lantern Transparencies. 
 
 NON-HALATION PLATES 
 
 (Double Coated without Backing, 
 and with Orthochromatic Quality). 
 
 A Plate for Universal Use for Interiors, Architecture, Marine, 
 and Landscape Views, Time or Instantaneous 
 Exposures, Portrait and Flashlight 
 Exposures, Glassware, etc. 
 
 Order a trial box of Eclipse, Junior , 
 
 Aplate for Professional and Amateur, of good quality, 
 extremely rapid, and sold at popular prices. 
 
 For Economy, Simplicity and Perfection in Development, use 
 
 CARBUTT’S J. C. TABLOIDS. 
 
 PRICES— 25c., 40c. and 75c. PER BOX. 
 
 FOR SALE BY ALL DEALERS. 
 
 Full descriptive circulars of Plates, Films and Specialties, mailed 
 on receipt of address. 
 
 Man " fa ^ d by JOHN CARBUTT, 
 
 KEYSTONE DRY PLATE AND FILM WORKS, 
 
 WAYNE JUNCTION, PHILADELPHIA. 
 
/ 
 
 EXTRA FAST, 
 
 For the Studio and Hand Camera — 
 The fastest plate on the market. 
 
 FAST, 
 
 Medium rapidity, for the Studio and 
 Landscape Photography, 
 
 SLOW, 
 
 for Landscape, Copying, Transpar- 
 encies and Photo-Mechanical Work. 
 
 Aurora Double Coated. 
 
 Same speed as Extra Fast, for Land- 
 scapes and Interiors, 
 
 X-RAY PLATES 
 
 made to order on Short Notice, 
 
 Sold by all 'Dealers 
 in Photo- Supplies. 
 
 Get the NEW DISCOUNT and 
 you will buy the Hammer Plate. 
 
 CHEAPEST FIRST-CLASS PLATE 
 
 on the MARKET. 
 
 Hammer 
 Dry Plate Co., 
 
 ST. LOUIS, MO. 
 
 Send for “HAMMER’S LITTLE BOOK,” a 
 Short Talk on Negative Making. 
 Mailed FREE to any Address. 
 
The New York Plate 
 
 ,s„ e FAVORITE for 
 
 Amateurs and 
 
 Professionals 
 
 on account of its gread speed, brilliancy, 
 ease of working and general excellence. 
 
 RECORD Brand tor Quickest Work. 
 NEW HARVARD “ “ Ordinary “ 
 
 CRESCENT “ “ Slow 
 
 SOLD BY ALL PHOTO STOCK DEALERS. 
 
TR ™ GOERZ # 
 
 Double Anastigmat 
 
 German Patent No. 74,437. 
 American Patent No. 528,155. 
 
 Before Buying 
 Another Lens. 
 
 
 It will give you better 
 definition, greater depth 
 of focus and more illumi- 
 nation, over the whole 
 of your plate than any 
 other lens on the market. 
 
 
 FOR SALE BY ALL 
 DEALERS OR 
 
 C P. GOERZ, ^ 
 
 52 Union Square East, 
 
 New York. 
 
 Factory at Berlin (Germany) 
 

I 
 

 ■ fctf JJ ^lWl> Vj'lEhjfefCj* ; 
 
 <?nfe\JA 
 
 
 V Vu i/ 1^ VA^ -tCy ^Qi^V 
 
 
 
 
 
 
 
 
 
 
 
 
 y/ *vV\a ^jvv'n 
 
 g?| 
 
 f W-Vvi ^ /ff? 
 
 
 ^ V -T 1 
 
 'j l V; yC^^V^T \fj,. ■<J&C\* e: >£ 
 
 sA. V,’ T^^V?V m^/rfc^B 
 
 
 
 
 
 
 
l GETTY RESEARCH INSTITUTE 
 
 3 3125 01025 9295