HISTORY OF OIIRONOPHOTOGRAPHY. 



327 



traverses the film, /, which carries the positive photographs, and these 

 photographs, magnified by the objective, are thrown upon the screen. 



The motion of the film at its halts at each flash :ire brought about by 

 an apparatus not shown in the figure. It is similar to that of the 

 simple chronophotographic apparatus, with the difference that the 

 positive film, having its ends fastened together to make an endless 

 belt, passes over a scries of rollers which stretch it taut. The princi- 

 pal imperfection of the chronophotographic projector was a jerkiness 

 due to imperfect equality of the intervals. 



Wo. 11. Edisotfs kinetoscope, 1891^. — Mr. Edison found a means of 

 equalizing the intervals. It was to perforate the sensitive film ))\ a 



Fig. 17. 



series of equidistant holes and gear it to a pin cylinder. It was impos- 

 sible to procure a kinetoscope to exhibit in the glass case; but every- 

 body, of late 3'ears, has seen this remarkable instrument in action. It 

 shows living scenes acted out for more than a minute with absolute 

 precision. In Edison's apparatus the film-ribbon never was arrested; 

 but the images were rendered sharp by the extreme brevity of the 

 illumination, which was only T „ 1 0I) of a second. A single spectator, 

 looking through eyepieces, could see the living pictures of the 

 kinetoscope. 



No. 12. Lumiere's cinematograph, 1895. — This instrument finally 

 gave the desired result — that is to say, the projection on a screen of 



