A Popular Treatise on Photography . Translated By W.H. Thornthwaite. The laboratory should be of such dimensions as are to meet the wants of the photographer.
Amateurs generally take plenty of room, because in most cases it.
The dark chamber ought to be, on the contrary, very simple Two or three tables are sufficient, and the light should either be entirely excluded by pasting black paper over the windows, and the operations conducted by the light of a candle or a gas jet, surrounded by a square lantern of yellow glass, or else, as often preferred, the dark room is so arranged that the light comes exclusively through a frame of yellow glass about 10 inches by 8 inches, and this covered with a sheet of very thin white paper, in order to impede the passage of the direct solar rays. A hinged frame is fitted in front of this square of yellow glass in such a way as to admit of its being totally or partially covered, in order to diminish or increase the amount of illumination at pleasure. It is necessary to select glass of a deep yellow colour, and avoid the paler kinds. The entrance is at the bottom of the room, and the door, for greater security, covered with a black drapery. A cistern of water, furnished with a tap, supplies the necessary means for washing, and underneath this is placed the sink, with a pipe to convey the waste water outside.