SPECIAL APPLIANCES FOE DEVELOPING FILMS.
There are several ingenious contrivances intended to facilitate the development of films. Among these may be mentioned the been continued for about a minute, the film should be reversed, and the operation re peated with the celluloid side downward till development is complete. This method is adopted to prevent injury to the softened gelatine by contact with the sides of the dish. The film is rinsed and fixed in a similar manner. The washing may be done by pinning the film over a drum or a square frame, as shown by Fig. 192, and placing it under the tap in a large basin or tub. After washing, it is drawn through a glycerine bath, made as before, and hung up to dry, the ends being pinned to prevent curling.
special form of dish shown by Fig. 193, in which the film is passed under the two bridges at each end, complete immersion in the developer thus being assured. Another device is shown by Fig. 194, where the film is drawn under a bent rod, carry ing a revolving roller, which may be ad justed to any height to suit different depths of solution. There are also other devices
for the purpose. One of these is in the form of a revolving drum, round the periphery of which the film is fastened, by the clips at A and B (Fig. 195), the drum being adjusted over the developing trough in such a manner that the bottom surface is immersed. By turning a handle the drum is revolved, and the whole film is passed through the solution. Fixing also is carried out with this appliance, and washing is accomplished by placing the drum under the tap, first removing the trough (see Fig. 196). If desired, the film may be dried on the drum, by standing is fastened at one end and caused to re volve by alternately pulling and the other end (Fig. 198). This arrange ment is, of course, only suitable for de- 1 velopment and fixing, the film being after-I wards detached and washed by any of the usual methods.