20 



THE MECHANISM OF 



Fig. 0. 



fly dowD to their normal length, carrying the curtain around 

 on its rollers with great rapidity; the openings flash past each 

 other and the impression is made on the plate. Fig. 6 is a front 

 view of three exposors, in the first of which, at the right, the 

 exposure is just ending; in the second it is just beginning, while 

 the third is still set. In this form of exposor, it will be noticed, 

 the opening or exposure begins, reaches its maximum, and ends 

 directly opposite the centre of the lens. 



Two releasing magnets are 

 shown in Fig. 7, one of them 

 (A) set, the other (B) released. 

 The twenty-four large cam- 

 eras (or twelve, as the case 

 might be), each with its sepa- 

 rate exposor, as just described, 

 were used in making the lat- 

 eral series of photographs of 

 all the motions investigated at 

 the studio excepting the most 

 rapid ones, and with excellent 

 results. But it can be seen 

 that they were not readily 

 portable, and therefore inade- 

 quate to do the work at the 

 Zoological Gardens and the 

 Gentlemen's Driving Park in 

 the short time that could be 

 spent at each of those places. 

 Besides this, it was desired to 

 obtain the different phases of 

 a movement not only in lateral photographs (those taken from 

 the side perpendicular to the direction of motion, as in the Cali- 

 fornia experiments), but from any point of view, or from several 

 points of view at the same time; and also to be able to make 

 changes of position quickly upon short notice. These facts 

 prompted Mr. Muybridge to design and have made two bat- 

 teries of smaller cameras, which more than fulfilled all the 

 requirements of portability and quick working, and rendered 

 possible the making of more than one thousand analytical sets 



