APPARATUS 



17 



the shoulder I; the endless curtain is revolved until the 

 front aperture O is raised to its proper position, when 

 the ring C is hooked upon the projecting point D. A 

 cord attached to the rubber bands B is drawn around 

 the pulley P, and a ring at its end is slipped over a 

 pin, which keeps the spring at a proper state of ten- 

 sion. Upon the com- 

 pletion of an electric 

 circuit the armature is 

 drawn towards the 

 magnet; the end of the 

 lever is released from 

 its contact with the 

 shoulder; the ring 

 C is released from the 

 projecting point D; the 

 front of the endless 

 curtain is drawn rap- 

 idly downward; the 

 apertures meet in the 

 center of the lens, 

 form a gradually ex- 

 panding and then con- 

 tracting diaphragm, 

 and the exposure is 

 made. A front view 

 exposors is seen in 



Fig. 



of three electro-photographic 

 Figure 3. The first of these represents the exposor 

 set and ready for an exposure; the second shows 

 the meeting of the apertures at the commencement 

 of an exposure; the third, their position near the 

 completion of the exposure, they having in the mean- 



