346 PHOTOGRAPHIC FACTS AND FORMULAS 
the number of seconds from the moment of entering until 
the appearance of the first outlines of the image, exclusive 
of the sky in landscapes. The number of seconds elapsing 
before the appearance of the image is the guide to the further 
development of the plate, which should be carried out accord- 
ing to the following table: 
Quantity of ammonia 
solution B diluted to %4 Total time of 
Time of first appear- strength to be added development including 
ance of image after image appears time of appearance 
Seconds ccm Minutes Seconds 
22 to 24 None 2 
25 to 27 2 2 15 
28 to 30 8 2 30 
31 to 35 15 2 30 
36 to 41 20 Z 30 
42 to 48 25 ha 30 
49 to 55 30 is 45 
56 to 64 | 35 3 0 
65 to 75 40 4 0 
over 75 45 5 0 
The additional quantity of B solution must be added when 
the outlines begin to appear. 
Almost every developing agent has been suggested, but the 
following are satisfactory: 
Sodium sulphite, dry 50 g 384 gr. 
Ammonia, sp. gr. 0.92 33 ccm 253 min. 
Potassium bromide 6g 46 gr. 
Metol 4¢g 31 gr. 
Hydrochinon IZ 92 gr. 
Water to 1000 ccm 16 oz. 
Or: 
Metol 6.5 g 50 ger. 
Hydrochinon 2.10 ¢g 16 gr. 
Sodium sulphite, dry 40 ¢ 307 gr. 
Potassium bromide Diss 19 gr. 
