This section is from the book "Complete Self-Instructing Library Of Practical Photography", by J. B. Schriever. Also available from Amazon: Complete Self-Instructing Library Of Practical Photography.
Inserting Slide In Plate Holder. You will notice that the handle or top part of the slide, which covers the plate in the holder, is painted a light color on one side, while the other side is black. When you load your holder, have the light side of the slide facing out. After you have made the exposure return the slide to its proper position, with the black side out; in other words, the black side should face the front of the camera after the exposure is made, indicating that the plate on that side of the holder is exposed. (See Illustrations No. 11 and No. 12 for the right and wrong way of inserting the slide in the slot of the holder.) Always push the slide in straight, and never one corner first, as that is apt to fog the plate.
94. By carefully following these directions no trouble will be experienced in keeping track of the exposure - i. e., knowing exactly which plates have been exposed and which have not.
Dark-Room. A room of some kind, in which to undertake all the operations of loading the plate holders, removing the exposed plates from the holders, developing the plates, etc., is necessary, except where the daylight loading films are used and the development is done in the now universally used film tank. This room is commonly termed a dark-room, and must be absolutely free from all white light or light of any kind that may act on the dry plate. To insure the room being perfectly dark, it is always a wise plan to wait two or three minutes in the room, after the door has beeen closed, until the eye has become accustomed to the darkness. Rays of light which were not then perceptible will make themselves apparent, and these should be carefully blocked out with cloth, felt or heavy black paper. The only light that can be used in the dark-room during the handling of the sensitive plate, from the loading of the holder until after the fixing of the plate, is the ruby light, which is non-actinic - i. e., has no chemical action on the sensitive plate.
96. A closet or the bath-room, or any other room, can, of course, be used for a dark-room, providing every possible avenue where light may enter can be closed. If it is not convenient to have a dark-room of this kind, load the holders and develop the plates at night, in a room from which every ray of white or actinic light has been excluded.
97. In the dark-room, aside from the ruby lamp, there should be a perfectly dry shelf, on which to load and unload the plate holders and keep the plates. There should be another shelf or small table, on which to develop, where the developing solutions, trays, etc., should be kept. If possible, a sink and running water should also be in the dark-room. If, however, these are wanting, a large basin or tray can be employed and provision made for one or two pails of water. Procure a large wooden pail and place a small faucet near the bottom. In this pail place clear water to use in mixing the chemicals and in rinsing the plates. Have another pail in which to pour the waste water, old developer, etc.
98. Shelves on the wall, on which to place various stock solutions, trays, graduates, etc., will be found very convenient. (See Illustration No. 15 of a temporarily ar-
Illustration No. 16 An Inexpensive Dark Room Sink See Paragraph No. 08.
Illustration No. 17 Loading Plate Holder See Paragraph No. 103 ranged Dark-Room, being a corner of a bath-room. Also No. 16, a cheaply constructed Dark-room, Sink, Shelves, etc.).
Note - Detailed descriptions of conveniently constructed darkrooms are given in Chapter XXXI (Home-Made Enlarging Apparatus Without Condensers).