326 



HISTORY OF CHRONOPHOTOGRAPHY, 



paper (fig. 15). When the whole was wound up round its spool before 

 being put in, the film was protected from light by outer layers of 

 opaque paper; and when the work was done and the film was wound 

 upon the other spool it was equally protected by the other terminal of 

 opaque paper so that it could be removed from the apparatus in the 

 light without ])ecoming clouded. 



This apparatus, which was easily used, suflSced for three years for 

 the writer's researches into the motions of man and of animals. Like 



Mu3^bridge, Anschiitz, 

 and Demeny, he aimed to 

 obtain, by Plateau's 

 method, the reproduction 

 of the analyzed motions. 

 At the exhibition of 1889, 

 a zootrope moved b}^ elec- 

 tricity showed animals 

 in motion, as well as men, 

 birds, horses at dift'erent gaits. But since the zootrope does not allow 

 man}' figures to be shown, the writer was restricted to exhibiting short 

 movements. He therefore cast about for methods of showing scenes 

 of long duration. 



No. 10. Ckron.oj^hotograpJiic pi'ojector, 1893. — This apparatus carries 

 an endless belt of photographs to the focus of an objective which pro- 

 jects them upon a screen. Fig. 16 shows the path of the raj^s in the 

 projector. A pencil of parallel rays, refiected b}^ a heliostat comes 



Fig. 16. 



from S, and falls upon a convex lens /j. This pencil brought to a 

 focus, passes at t through a hole in a diaphragm, meets the shutter- 

 disk d., which is turned by a crank, passes through every window that 

 comes, then diverges and, meeting the lens 4, similar to the first, regains 

 its parallelism, is reflected at 45^ from a mirror forming the lid of the 

 box, falls vertically upon another mirror at the .■^ame inclination, and 

 now passes to the objective. But in this last part of its course it 



