DEVELOPMENT 7/7 
Pyro Bromide Factor Pyro Bromide Factor 
gr. peroz. gr. vi OZ. 9 gr. per oz. 0 18 
2 y 5) 2 0 12 
3 % 4¥ 3 0 10 
4 1 4 4 0 8 
8 2 3% 5 0 6Y% 
Estimated factors for American pyro-soda developers: 
Seed A. B. C., no bromide 11 
Seed pyro, no bromide 11 
Stanley, no bromide 10 
Cramer, maximum strength 6% 
Cramer, minimum strength 11 
Hammer, no bromide 11 
Eastman, no bromide b2 
Should the negatives obtained by the use of the above factors 
seem too thin, the factors must be increased; if the negatives 
are too dense, the factors should be decreased. The factor 
for a combined developer with the reducing agents in equal 
ratios is the mean of the two; for instance: 
(Pyro = 6+ metol = 30) —2=— 18 
If the developing agents are in different ratios, the factor for 
each is multiplied by the number of parts, and the sum of the 
factors divided by the number of parts of developer agents 
used. For instance, pyro 4 parts plus metol 2 parts: 
64 — 24 and\30) <2 —— G0 
24+ 60—84and 4+2=— 6 
then 84 — 6 = 14 the factor required. 
THERMO-DEVELOPMENT (Watkins)—While the normal 
temperature for development is assumed to be 18° C. 
(65° F.), it is not always convenient or possible to obtain this 
temperature exactly, and, as the rapidity of development is 
increased with a rise of temperature, and decreased with a 
colder solution, allowance must be made for the change of 
