134 SCIENCE OF HOME AND COMMUNITY 



are washed with water, and the hypo is added. In this 

 process one does not look at the plates at all while developing. 

 Kodak film tank. Films may now be developed without a 

 dark room by using the kodak film tank. (See figure 43 . ) This 

 consists of a wooden box, a light-proof apron, a transferring 

 reel, and a metal cup. At one end of the box the film is 

 fastened, and at the other end is placed the light-proof apron 

 wound around an axle. Between the two is the transferring 

 reel. The ends of both the film and the apron are fastened 

 to this reel. The cover is put on, and then by means of a 



FIG. 43. Kodak film tank. 



handle on the outside of the box the film and apron are wound 

 together on the same reeL 



The box is opened and the reel is taken out and put into 

 the metal cup, into which the developing solution has been 

 poured. The apron surrounding the film is perforated with 

 many small holes through which the solution reaches the 

 film. It is allowed to stay in the solution twenty minutes. 

 If two powders are used, it is developed in ten minutes. 

 The time also varies according to the temperature, more 

 time being required for low temperatures. The developer 

 is then poured out, and the reel is rinsed several times in 

 water. The reel is then taken out, and the apron and film 

 unwound. The film is separated from the red paper and 



