Hepworth, Thomas Cradock, -1905 · London : Hazell, Watson, and Viney · leaf 24
12 EVENING WORK FOR is, therefore, a valuable one, and more especially because it can be used in the dimmest of red lights, for the plates submitted to it centre themselves automatically. It is shown at fig. 3. It measures about 22 by 17 inches, and consists of a strong board, upon which is placed… … Fig. 3. attached to the base-board by the two central pins on its top and bottom pieces, upon which pins these pieces are free to turn. It is evident that if these top and bottom pieces be turned on the screws, they must come oblique to the board, and at the same time the uprights b b will, while…
Slides (Photography) · Photography
Internet Archive · Getty Research Institute · Public domain (published before 1931). Free to use for anything.