THE HORSE— A MACHINE 7 



The centre of gravity in the horse, standing naturally, has 

 been fixed at that point in the median vertical plane of the body 

 where a perpendicular line from the posterior extremity of the 

 breast-bone intersects the line of division betvireen the lower and 

 middle thirds of the body divided horizontally (Fig. 4). The 

 centre of gravity is stationary only when the horse is standing 



O- -f) 



Q...._Q 



Q 



Q 



P 



^ 







Q 



n 



t) 



o 



Fig. 5. — Diagram showing contact of feet in various gaits. A, standing, rectangular 

 base of support; B, walking, triangular base of support; C, trotting, linear base of support; 

 D, running, point base of support. 



absolutely still. When moving, there is a constantly repeated 

 displacement; ultimately in the direction taken by the leading 

 foot, although prior to the commencement of the stride, there is 

 a momentary displacement in the opposite direction, as the 

 weight is shifted to the supporting leg in order to reduce the 

 weight on the side of the foot to be advanced. 



