SYNTHESIS OF MOVEMENT 315 



for brief intervals by an arrangement of fenestrated 

 diaphragms, as used in ehronophotography. The short- 

 ness of the exposures, and the perfect working of this 

 apparatus, represented the images as immovable, and 



Fig 204. — Derueny's photophone. 



fhey appeared exactly at the same spot, in spite of the 

 rotation of the disc upon which they were placed.* 



These photographs give such a perfect representation 

 of speech that deaf mutes accustomed to read the 

 movements of the lips have been able to recognize 

 the words spoken by the person photographed. 



* This instrument was designed by M. Demeny, and called the 

 "Photophone " (C. R. de VAcademie des Sciences, July 27, 1891). 



