CHAPTER V. 

 THE HORSE IN MOTION. 



The horse is used by man for various purposes that 

 require movement as the prime factor. This ranges from 

 the slow and powerful walk of the draft horse to the swift 

 gallop of the light runner. In a horse standing at perfect 

 rest, we observe a large, heavy body or trunk, suspended 

 by the spine between four upright supports, the legs. When 

 the body of the horse is at rest, it is in balance or equi- 

 librium from a certain imaginary point within the body 

 where is located the center of gravity. The position of 

 center of gravity, according to Colin, a French authority, l 

 is at a point in the body which corresponds to the intersec- 

 tion of two lines, one vertical and one horizontal, that meet 

 slightly below the center of the chest cavity, on a line with 

 the back edge of the eighth rib. "It is clear," says Colin, 

 "that the position of the center of gravity and the distri- 

 bution of the body upon the members (legs), must vary 

 according to the conformation of animals, whose head, neck, 

 abdomen, and croup, present such diverse proportion.' 7 

 When the horse is in motion, and extends his head and 

 neck, he shifts his center of gravity forward. The im- 

 portant point in this connection is, that equilibrium be 

 maintained while in motion. This will be secured in the 

 greatest degree by a gravitation that does not reach the 

 ground, yet which, through shortness of leg, provides a 

 strong support and easy recovery of equilibrium. Locomo- 

 tion is only secured by the moving forward of the leg, thus 

 shifting what is known as the base of support below the 

 center of gravity. 



1 The Exterior of the Horse. Goubaux & Barriere, 2d Am. ed., 1904, p. 5. 



48 



