THE GAITS IN PARTICULAR. 563 



and was executed almost upon place, being more like a riding-school 

 pcoxide than a true gait. 



Gallop of the Race-Course (Running Gallop). 



As soon as the ordinary gallop exceeds a certain velocity the simul- 

 taneous beats of the second contact commence to be disassociated, and, 

 at the same time, the diagonal base augments progressively in length. 



This gait insensibly jiasses into a new one, which has received the 

 name riuin'mg gallop, and in which the members appear to act sepa- 

 rately in pairs (anterior and posterior). 



It is this very character of apparent independence between the 

 anterior and the posterior members that led ancient horsemen to believe 

 that this variety of gallop was effected wiih two times. 



We know to-day that such is not the case. It is a gallop with four 

 times, unequal and very rapid, which presents great analogies with that 

 of the photographs from Lissa, of whicli Fig. 242 reproduces the 

 notation. 



The honor of having demonstrated in a positive manner the exist- 

 ence of the disassociation of the diao-onal beats in this orait, in conse- 

 quence of the reality of its four times, reverts to M. Marey.^ 



But here the violence of the jiedal percussion in this gait is so great 

 that the experimental apparatus had to be modified so as to become more 

 durable. Unfortunately, there resulted from this modification less 

 acute sensitiveness of the instrument, which makes tl>e representation 

 of the order of the contacts scarcely accurate. In this connection it is 

 evident that great and numerous improvements have yet to be made 

 in the graphic method. 



The thorough analysis of the instantaneous photographs of M. 

 Muybridge, taken from the American race-horse Sallie Gardner, which 

 was moving at a velocity of 1142 metres per minute, has permitted M. 

 Lenoble du Teil to make the verification of the facts more exact and 

 more complete.^ 



Fig. 254 is a true reproduction of these photographs. 



Upon the notation which corresponds to them (Fig. 255) it can be 

 seen : 



1st. That the contacts of the right members take place respectively 

 at the commencement of the last third of the contacts of the corresj)ond- 

 ing left members. 



2d. That in the disunited diagonal biped, PD, A G, the anterior left 



1 Marey La machine animale, p. 177. 



* Lenoble du Teil, Le galop et la course, p. 9, et suiv., Argentan, 1880. 



