LANTERN SLIDES FROM CELLOPHANE JOHNL. WILSON,UNIVERSITY
OP
MINNESOTA, MINNEAPOLIS, MINNESOTA
Methods of making lantern slides f r m cellophane or from cellulose acetate sheets are described. No special equiptnent i s required.
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Some time ago it was necessary for the author to prepare on very short notice several lantern slides. Having no experience in this field and no special equipment the following method was tried. The material to he shown was typed on thin sheets (cut to the lantern slide size) of clear cellophane and mounted between two lantern-slide glasses. The success of this emergency method was so satisfactory that it was thought worth following a little farther. In the several articles on the preparation of lantern slides, ( I ) to (9),found in the literature there appears no method so easy and simple as this one. It was found that for tables, and such data as could be typed, the most satisfactory results were obtained if, when the typing was done, a carbon paper was so placed behind the cellophane that a double impression was obtained, one on the front side from the typewriter ribbon and a second on the back from the reversed carbon paper. A typewriter which has "pica" type is more suitable for this purpose than one with larger type as it allows much more material to be placed on the slide and a t the same time is large enough to be read easily when projected in the ordinary way, even from the hack of a very large room. If sheets of cellophane about five-one-thousandths of an inch thick are used, the sheets are stiff enough to be much easier to handle than the thinner sheets and yet are thin enough to be used in the typewriter satisfactorily. These prepared sheets are then permanently mounted between two glass slide-covers in the regular way or between two pieces of cellophane of an inch thick). of the same dimensions ( i . e., 31/4 X 4 inches and Another method is to hinge two glass or cellophane pieces (of the above dimensions) together, along the bottom, with a piece of tape and then leave the typed sheet in this holder only while using in the lantern.* Only two such holders are necessary and by this means the weight of, and the space occupied by, a large number of slides is greatly reduced. Care must be taken, however, not to smear the carbon typing on the back of the slide; this may be prevented by covering the back with another thin sheet and gluing the corners together. Material such as curves, figures of apparatus, etc., which cannot be typed may be drawn on these sheets with India ink. For these slides the trouble of mounting may be avoided by drawing on thicker sheets to '/I6 of an inch thick) and using these, just as they are, for slides.**
* I am indebted to Dr. George Glockler for this idea.
** This method was tried at the suggestion of Dr. G. B. Heisig. 2212
VOL. 8, No. 11
SLIDES FROM CELLOPHANE
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Black India ink shows up best on the screen but other colors work well enough to allow one to use several colors on the same slide to distinguish hetween different curves or different parts of the apparatus shown. The latter type of slide is especially suited for the case where a slide is to be used only temporarily, as, for example, for a seminar talk or a single lecture. The figures may often be traced directly onto the slide and the material presented more accurately and easily than if the drawing is transferred by eye from the text to the blackboard. No great time or expense is involved in the makimg and when one is through using the slide the ink may 6e washed off and another slide made with the same piece of cellophane. There is no danger of the cellophane being ignited in the ordinary projection lantern. However, if, for some particular lantern, such danger exists one may use the so-called non-inflammable cellulose acetate sheets* These slides do not give as good a projection as the best of the slides made in the regular manner but do give very satisfactory results, and from some points of view are to be preferred to the regularly made slides.
* Sheets of cellophane and cellulose acetate of various thickness can he obtained in many large cities a t department stores or stores handling engineers' and architects' supplies, or direct from the manufacturers. Cellophane may be obtained from: The dn Pont Cellophane Company, Buffalo, N. Y. Cellulose acetate (trade name, "Plastacelle") may be purchased from du Pont Viscoloid Company, Arlington, N. J. Literature Cited SCHRIEVER, "Complete Self-Instructing Library of Practical Photography." Popular Edition, Volume V, American School of Art and Photography, Snanton, Pa., U. S. A., 1909, pages 297-348. "Lantern Slides: How t o M a k e and Color Them," Eastman Kadak Company, - . Rochester, N. Y. Po~zo." S i m ~ kMethod for Preparina Drawings on Glass Lantern Slides," Z. bid. ~ e c h n i k . ~ e t h2 ., ,4 6 7 (1910). D e m ~ "Composition , for Coating Lantern Slides," U. S. P., 1,055,720, March 11, 1913. PETTIE,"Lantern Slides." Brit. Pat. 6885, March 20, 1913. FERRIERAND PETERS,Brit. Pat. 104,742, March l i , 1916. "Warm Tone Lantern Slides: The Relation between EnBAKERAND DAVID~ON. posure, Development, Color, and Gradation," Brit. J. Phot., 71,77-9 (1924). Johnston. "Thiocarhamide Lantern Slides," Phot. J.. 66, 159-62 (1926). Rolfe. "Notes on Photomicrography." Chemist Analyst. 19, 16 (March, 1930).
The mesent centurv is one in which the mantle of Dower is assi inn- to the chemical industries. I n all branches of production mechanical processes give way to chemical. -IGNACB MOSCICRI, PmidCnt of Poland
