RECENT ADVANCES IN PHOTOGRAPHY. 4 c 3 



Another very decided advance in photography is the doing away 

 with glass as a support for the emulsion. Mr. Warnerke has perfected 

 a process by which the photograph is taken on paper instead of on glass. 

 He has a sensitive tissue which can be made of any length, and can be 

 l-olled on a roller and exposed in the dark slide. By turning another 

 roller, a fresh surface is brought into the plane of the focusing-screen. 

 The sensitive tissue is developed in the ordinary way with alkaline 

 development. The film can be either stripped off, or else transferred 

 to glass. In the latter case, we come to another point which marks a 

 distinct advance. Mr. Warnerke has found that when you develop a 

 gelatine plate with alkaline development, the parts which have been 

 acted upon by light, and which have been developed, become insoluble 

 in hot water. He is thus able, after development, instead of using the 

 hyposulphite bath to fix the print, to transfer it to glass, and wash 

 away with hot water the parts of the film which have not been acted 

 upon by the light ; and he thus gets a transparency. To do this, it is 

 necessary that the back surface of the gelatine film should be exposed 

 to the water, as in carbon printing, and this is secured by transfer to 

 glass. Mr. Warnerke is not satisfied with doing away with glass for 

 the camera, but he does away with glass for printing ; and, in order to 

 accomplish this, he retransfers the negative from the glass to a sheet 

 of gelatine. I may say that the glass is freshly collodionized, and this 

 enables the film to strip off readily. It is one of the advantages of 

 these negatives that you can print from either side, each one yielding 

 sharp points a desideratum when using processes where reversed 

 negatives are required. In the matter of gelatine films, we have Pro- 

 fessor Stebbings's, which are really workable. The gelatine emulsion 

 is apparently flowed on an insoluble film on glass, which is then 

 stripped. 



The next point I touch upon is the enlargement of negatives. The 

 best way I know of, of getting an enlargement of a negative, is one 

 that was brought forward a few years ago by Mr. Valentine Blanchard. 

 He takes the original negative which he wishes to enlarge, and places 

 it in an enlarging camera. He then takes a transparency of the exact 

 size he wants his negative to be. He next takes a piece of common 

 albumenized paper, and prints that transparency upon it, and by this 

 means gets a very soft and beautiful negative. If you have a hard 

 negative, it is almost impossible to get a soft transparency by the wet- 

 plate process ; but, by this artifice of " printing out " your transpar- 

 ency and using that as a negative, you get a decidedly soft paper 

 negative. 



One of the new applications of the gelatine process is the develop- 

 ment of a print on paper coated with gelatino-bromide. The paper is 

 prepared by coating ordinary paper with gelatino-bromide (of the 

 most sensitive kind, if you like). Such paper can then be exposed to 

 the image formed by an ordinary magic-lantern ; by that means you 



