u 



CHAPTER VII. 

 REQUISITES FOR PHOTOGRAPHY. 



HAVING already remarked upon the advantages of ample dark- 

 room accommodation, running water and a waste-sink, we may 

 now enter somewhat into detail regarding dark-room arrange- 

 ments and articles used in operations purely photographic. 



In arranging for non-actinic illumination the reader is ad- 

 vised to prepare himself at the outset for u color correct " or 

 orthochromatic " photography, for the worker at general 

 photo-micrography, if he pay any attention whatever to the 

 words of the author of this book, will very early find himself 

 using color-sensitive plates. This means that whether the 

 the reader proposes to use as a gene'ral rule yellow diffused, or 

 clear ruby light, he must provide himself at all events with 

 ruby illumination. If development is to be conducted by day- 

 light we recommend that the outer sash of the window be 

 glazed with yellow glass, or at least three thicknesses of " can- 

 ary medium" known to all photographic dealers. For ordin- 

 ary plates a sash of ruby glass should be added to the yellow 

 glass, and the best in fact practically the only good ruby 

 glass is " flashed ruby " on one side and " stained yellow " on 

 the other. A splendid glass, if it can be got, is flashed deep 

 ruby on one side and ground on the other side. The three 

 thicknesses of canary medium may suffice if the light shining 

 on it be not very strong, and if a thickness of good ruby glass 

 be added, or two layers of good " ruby fabric," the window is 

 probably trustworthy for even ortho-chromatic plates. If arti- 

 ficial light be used the flashed and stained ruby glass may suf- 

 fice in a single thickness for even color-correct plates, though 

 this must be tested ; it will almost certainly suffice for any or- 

 dinary plates; two thicknesses of the canary medium for 

 ordinary plates, with the addition of ruby glass as before for 



