140 ANIMAL MECHANISM. 



see all the rhythms of the movements which characterise 

 the different pairs of the horse reproduced. 



Every one has seen in the circus or the masquerade those 

 figures of animals whose legs are formed by those of two mei* 

 witli their bodies concealed in that of the horse. This gro- 

 texjut; imitation bears a striking resemblance to the animal, 

 when the movements of the two men are well co-ordinated, so 

 as to reproduce the rhythms of the paces of a real quadruped. 



In the examination of the tracings furnished by the graphic 

 method when applied to the paces of the horse, we may have 

 recourse to the theory propounded by Duges; we shall then 

 find the curves furnished by human locomotion twice repeated. 

 We shall see that the difference between one pace and another 

 consists in the manner in which the footfalls of the hind leg 

 of a horse succeed each other, with relation to those of the 

 fore leg on the same side. But this determination of the 

 order of the succession of footfalls presents singular dilli- 

 culties, even for the most skilful observers. 



Many attempts have been made to bring to perfection the 

 means of observation, and to remedy the insufficiency of 

 language in the description of the observed phenomena. 

 Long since, the rhythm of the steps according to the sounds 

 which they produce has been substituted for their examination 

 by means of the eye. The ear, in fact, is better adapted than 

 the eye to distinguish the rhythms or relations of succession. 

 To ascertain the order in which each limb strikes the ground, 

 certain experimenters have attached to the legs of the horso 

 bells of different tones, which can be easily distinguished from 

 each other. 



A point \vhich has been better ascertained with respect to 

 the locomotion of the horse, is the determination of the space 

 passed over on the ground during each of the various kinds 

 of paces. This space has been directly measured by means 

 of the distance between the prints of the feet left on the 

 ground. To render the distinction between the footprints 

 more easy, each of the animal's feet has been shod in a 

 iliHiTcnt manner. Besides this, observers have studied the 

 proportion which exists between the. height of the animal and 

 the length of its various paces. All tho.su who have made 



