Photomicrographs and Lantern Slides 143 



in good diffuse daylight, with an F 16 stop and a lantern-slide plate, 

 try 15 seconds. 



In copying maps and line drawings, where dead blacks and 

 pure whites are desired, expose fully and overdevelop, even until 

 the image shows plainly on the back of the plate. 



It is not necessary to furnish formulae for developers and fixing 

 solutions, since these are furnished with every box of plates. We 

 have found the Cramer plates very satisfactory for all kinds of 

 photographic work. The firm will send gratis to anyone who requests 

 it Cramer's manual on Negative -Making and Formulas (G. Cramer 

 Dry Plate Co., St. Louis, Missouri). 



To the formulae in common use may be added one by Dr. Land. 

 It is good for general work and gives particularly brilliant results 

 with lantern slides. It will develop an underexposed plate when 

 the usual developers fail. With this developer, the image flashes 

 into sight with surprising suddenness, but do not become startled and 

 remove the slide too soon, lest you fail to secure details. 



Land's Developer. 



Hydrokinon 8 g. 



Metol 3 g. 



Sodium sulphite (dry) 30 g. 



(60 g. if crystals are used) 

 Sodium carbonate (dry) 30 g. 



(90 g. if crystals are used) 



Potassium bromide 2 g. 



Water 1,000 c.c. 



Warm Tones. -A pyro-ammonia developer for warm tones is 

 recommended in Harrington's Photographic Journal for June, 1914: 



Metric Apothecaries 



A. Pyro 31 g. ( 1 oz.) 



Sodium sulphite crystals 62 g. ( 2 oz.) 



Citric acid 2.6g. (40 g.) 



Water 237 c.c. ( \ pint) 



B. Ammonia 31 g. (1 oz.) 



Water 237 c.c. ( \ pint) 



C. Ammonia bromide 31 g. (1 oz.) 



Water 237 c.c. ( \ pint) 



