5« 



MECHANISM OF EQUINE LOCOMOTION. 



centre of gravity of his body beyond the toe of the most advanced fore foot, 

 witli the result that the other fore leg has to be carried forward in order to restore 

 the equilibrium. In doing this, the first foot to quit the ground will usually 

 be a fore one. I may remark that a succession of these displacements and 



Fig. II. 



Fig. i: 



Fig. id. 

 Displacement of Centre of Gravity by Man when Walking. 

 recoveries will constitute the walk, run, or other pace. The same movements 

 occur in leaping, except when the spring is made vertically upwards from 

 a state of rest, in which case the centre of gravity is not displaced beyond 

 the base of support. 



Manner in which Propulsion is Effected by the Limbs.— 



The displacement of the centre of gravity, in the propulsion of the body, 

 is accomplished by the straightening out of the limb or limbs, as the case 

 may be. We can readily see how this gives the required impetus, if we 

 consider the manner in which the shove-off is done by an expert swimmer in 

 a bath, when he comes to the end of it, and wishes to touch, turn, and strike 

 off without loss of time. He, as we all know, will, as much as possible, draw 

 up the leg with which he is going to give the shove-off, and having applied it 

 to the side of the bath {see Fig. 13), will suddenly straighten it out, with 

 the result that his body will be shot forward {see Fig. 14). Here, the 

 drawn-up leg, which acts as a spring, is placed between two objects : one 

 (the body) movable, the other (the side of the bath) immovable. When 

 the leg is extended, the movable object is naturally the one to be displaced. 

 Identically the same action occurs in the various progressive movements of 

 the horse. We may see it, also, in the run of the pedestrian, which is depicted 



