I2 6 APPENDIX. 



hardly conceivable. In like manner, as the wheel passed over the 

 second wire, the shutters would be liberated on the second camera, and 

 so on until the whole series were discharged. When the horse passed 

 with great velocity over the wires these shutters were discharged with 

 such force and rapidity that the horse was not unfrequently startled 

 and broke his gait. 



If everything was properly arranged the driver had but to keep the 

 wheel of his sulky in the groove which was sunken for it, and it 

 would, by depressing the wires successively, take the pictures at every 

 twenty-one inches until the whole series were taken. 



The method just described was used in all cases where horses were 

 driven to sulkies ; but when wheels were not used this arrangement 

 with wires under the track had to be modified, and a thread was 

 drawn across sufficiently high to come in contact with the horse's 

 breast, and strong enough to cause the contact and establish the 

 circuit as before, but not so strong as to wound the horse when 

 going at full speed. 



By these methods many views were taken and distributed to all 

 parts of the country : they attracted a great deal of attention, and 

 elicited a great variety of opinions and not a little ridicule ; some 

 artistic persons displayed great ingenuity in burlesque, no one under- 

 stood them. 



The number of cameras was afterwards doubled, and they were 

 placed at intervals of twelve inches to still closer analyze the move- 

 ments of the horse. Lines were drawn across the track at correspond- 

 ing distances, and the numbers indicating them, instead of being at 

 the base of the screen, were on a board between the horse and the 

 cameras. The heliotype plates Nos. CVI. and CVII. represent the 

 battery of cameras and the screen as they were when twenty-four 

 cameras were in position. 



The whole of the series of twenty-four figures each used in this 

 volume to illustrate the paces were taken in this manner. They were 

 very accurately taken, and are specimens of the best results attained 

 after years of expensive experience ; and the heliotypes are perfect 

 transcripts of the original photographs. 





