324 



HISTORY OF CHRONOPHOTOGRAPHY. 



Still, it was desirable to multipl}^ the images while showing the 

 whole bod}'. For that purpose the insufficiency of the advance of the 

 subject has to be made up for by a displacement of the image on the 

 plate. This can be brought about in several ways. In the first place, 

 the camera, with its attachments, can be pivoted on its support and 

 caused to turn about a vertical axis. The difficult}^ of moving the 

 considerable mass uniformly caused, however, the abandonment of this 

 method in favor of the rotation of a mirror T)y clockwork, causing the 

 reflection to strike different points of the plate. In this way a series 

 of complete photographs are obtained, following one another at 

 extremely short intervals of time. Indeed, the frequenc}^ of the 

 photographs may be made very great. Their total number is, how- 

 ever, restricted because the optical axis of the instrument, being dis- 



FlG. 12. 



placed along the black background, soon reaches the end of it. A 

 final solution was to take the photographs upon difi'erent points of a 

 long fillet which moves along the focal plane of the camera and is 

 stopped long enough for each exposure. 



Chronojyhotography on a Jilm rihhon, Morey^ 1887: In consequence 

 of the invention of the kodak, long paper fillets of gelatino-bromide of 

 silver had become articles of commerce. A little later transparent 

 films made their appearance; and these were still more appropriate for 

 the chronophotography of long series of pictures. Three patterns of 

 apparatus were exhibited in the case under No, 8. These showed the 

 successive steps of invention. 



Type a: The apparatus (fig. 12) worked in the red light of the dark 

 room. The objective was pointed outward across a conical shade. In 

 the place of the ordinary plate-holder was placed a shelf carrying a 



