CH. XI] 



MOVING PICTURE APPARATUS 



407 



574. The film magazines are large sheet iron.: boxes which 

 hold the film reels. They are big enough to hold the standard 

 25 cm. (10 in.) reel and it is a convenience if they are large enough 

 to hold the larger reels of 30 cm. (12 in.) diameter. The film 

 magazines are fitted with fire traps to prevent any fire getting into 

 the magazine if the film should start to burn. 



FIG. 225. MOVING PICTURE MECHANISM WITH INSIDE SHUTTER, I S. 

 For full explanation see Fig. 231. 



INSTALLATION OF A MOVING PICTURE OUTFIT 



575. After the wiring to the operating room has been installed 

 in accordance with the fire underwriters regulations and any special 

 regulations of the city in which the work is done, all is ready to 

 connect in the rheostat, transformer, or other regulating device 

 ( 7 2 8, 736) and to attach the wires to the arc lamp. 



These connections are exactly like those for the magic lantern 

 (fig. 3) when a rheostat or inductor (choke-coil) is used. When a 

 transformer or mercury arc rectifier is used, the primary side is 



