inous, it is liable to abrasion; and care should be taken to avoid the prints dragging over each other, or over the bottom of the dish.
There are a few precautions to be carefully observed in development. It is most important to preserve uniformity of action. If, for instance, an air-bubble form, at any period before development is complete, the film of air protects the spot from the solvent action of the water, and the picture will be darker in that place. If the picture be suffered to float with the face partially out of the water, the same thing will happen. It is desirable, therefore, to keep the face downwards until the operation is completed, and to remove air-bubbles whenever they form. It should further be remembered, in observing the depth of the picture, that it is now seen on a ground considerably degraded by the coating of India-rubber, which gives the paper a brown tint, and that when transferred to pure white paper, it will possess much greater brilliancy.
TRANSFERRING THE PRINTS.
The picture, up to the present time, presents an image in which right and left are reversed. It is now necessary, therefore, to transfer it from the paper which has supported it temporarily for the purposes of manipulation, to its final resting-place, in which operation the right and left will resume their proper relations. The image may be either transferred to a sheet of cardboard, so as to require no further mounting, or to paper; in the latter case, it is simply in the position of an ordinary print, and will require subsequent mounting. Each method has certain specific advantages, but generally the transfer to paper is to be preferred.
Transferring to Cardboard.—The face of the dried print
