PPIOTOGRAPHY 195 



exposed, and should be thrown away. In case it "comes up" less quickly, 

 indicating that it is not greatly overexposed, it can be saved by the addition 

 of more bromide. When the image does not show till the end of five to 

 ten minutes, the plate has been underexposed. It is then necessary to add 

 more "pyro," taking care not to pour it on the plate, and, after the image 

 appears with its striking contrast, to leave the plate in water until as much 

 detail as possible is brought out in the shadows. In the case of a normal 

 exposure, \vhen greater detail is desired, the negative is left for some time 

 in water, and when contrast is sought more "pyro" is used. Negatives 

 with unusual detail lack ''snap" ; they are "flat," and fail to make artistic 

 pictures. Contrast, on the other hand, often obscures detail, and the best 

 results can only be obtained by a happy combination of the two. The 

 most important maxim in developing is that the process shall be con- 

 tinued until the image has become indistinct. The universal tendency of 

 the beginner is to remove the negative the moment the outlines grow 

 dimmer, and the result is a thin, lifeless negative. It is almost impossible 

 to develop too far, if the image is not allowed to disappear. Negatives of 

 this sort are "thick," and though they print more slowly, produce brilliant 

 pictures. A large quantity of the developing solution is used with single 

 plates in small trays, and is allowed to act without rocking the tray. Much 

 time is saved, how^ever, by developing several plates together, and to avoid 

 using a large quantity of the solution, the tray is gently rocked from time 

 to time. This movement is particularly necessary at the beginning, in 

 order that the plates may be covered evenly, and at once. Fifty cubic centi- 

 rneters of the solution will develop three or four 6J/2 x 8^^ plates, and twice 

 as many 4 x 5's. After the developer has once been used, it is kept for 

 several days to restrain overexposed plates. As soon as the plate is 

 developed, it is rinsed in water, and placed in the fixing fluid, until the 

 white opaqueness is entirely removed. The "hypo" is then washed out 

 by immersing the negatives for one to two hours in running w-ater. If the 

 latter can not be secured, the water in which they are placed should be 

 changed frequently. The negatives are then air-dried within doors, in a 

 place free from dust. Finally, they are filed away in negative envelopes, 

 each bearing the name and number of the negative, and preferably also, 

 the time and other exposure data. 



242. Finishins:. On account of the time demanded by other field tasks, 

 it has not been found desirable to make and finish prints in the field. This, 

 with the making of lantern slides, enlargements, etc., may well be turned 

 over to a professional photographer. It is the custom to make a proof of 

 each negative to meet the casual needs that arise in the field. For this 



