164 ROAD, PARK, AND SCHOOL 



maintain the collected form that permits a hind-foot 

 and its diagonal fore-foot to come to the ground 

 together, we have an extended pace of four beats, 

 which we shall call the full gallop. In the full 

 gallop the horse goes into air from a fore-foot, 

 receives the weight upon the diagonal hind-foot, 

 then plants the other hind-foot, then, taking the 

 weight upon the latter, extends itself and plants the 

 diagonal fore-foot, takes the weight upon the latter, 

 and then plants the other fore-foot, which then 

 alone sustains the weight until the centre of gravity 

 passes over it, when the horse again goes into air 

 to alight upon the diagonal hind-foot planted in 

 front of the spot just vacated by the last-mentioned 

 fore-foot. Thus we have the mass, driven by the 

 hind-legs, and carried on by its momentum, passing 

 over four crutches in each stride ; the impulse from 

 the hind-legs (aided perhaps to some extent by the 

 muscular action of the fore-legs) renewing the 

 momentum, so that a tolerably even rate of high 

 speed is maintained. 



That the fore-legs have very little, if any, pro- 

 pulsive force, may be seen in the hand gallop ; for 

 here, where the momentum is not sufficient to over- 

 come the gravitation of the mass, the impulse (as 

 the photographs in my book on The Gallop show) 

 that enables the horse to go into air from the leading 



