No, 7. DEPARTMENT OF AGRICULTURE. fi89 



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of gravity, the wider the base represented by his four feet, and the 

 more nearly the center of gravity lies in the center of this base, the 

 more stable the equilibrium, consequently the greater the force. 

 On the contrary, the higher the center of gravity the smaller the 

 base and the farther forward the center of gravity the less stable 

 his equilibrium and the greater his speed. In other words, a tall 

 horse does not run fast simply because his legs are long, but because 

 his center of gravity is high and his equilibrium unstable. 



This fact is well shown by the difference in speed between running, 

 pacing, trotting and walking. In running, the horse's equilibrium 

 is the most unstable because his feet are entirely off the ground at 

 certain times — hence the horse is required to make greater effort 

 to restore his equilibrium. This causes him to go faster. In the 

 same way, the equilibrium of the pacing horse is less stable than 

 that of the trotting horse, because in pacing, the two feet on one 

 side of the horse are taken off the ground at the same time and the 

 center of gravity consequently falls entirely without the base; 

 while in trotting, feet on opposite sides are taken from the ground 

 at the same time and the center of gravity is almost unbroken in 

 a straight line between the two feet which remain on the ground. 

 The pacing horse, therefore, is required to make greater effort to 

 regain his equilibrium and in consequence goes more rapidly than 

 the trotter. In walking there is never less than two feet on the 

 ground at anytime and part of the time there are three. 



For force, we must have weight in order that a sufficient resist- 

 ance may be offered to the load which it is desired to move, and also 

 that we may have muscles and bones of sufficient size to obtain the 

 requisite power. For speed, on the other hand, we must have long 

 bones and long muscles in order to have quick motions. A horse 

 that is low and massive also has the bones of his members at a more 

 advantageous angle for force, that is to say more nearly at right 

 angles with one another, while the horse that is high has the bones 

 of his members at a wider angle which is more advantageous for 

 speed. 



By attitude is meant the relation of the feet and members to the 

 body. It is obvious to anyone who stops to think about it, that 

 the best position for a milk stool is when the bottom of the leg is 

 directly under the top of it; in other words when the leg of the 

 milk stool is vertical. If it happens that the leg of the milk stool 

 is crooked, it does not change the fact that the bottom end of the 

 leg should be directly under the top end and that the seat of the 

 stool should be at right angles to a line drawn from the top end to 

 the bottom end of the leg. The same mechanical principle applies 

 to horses. The most advantageous position for the feet of the horse 

 is when they are directly under the points of attachment with the 

 body. If the front feet are farther under the body than this, more 

 of the weight of the body is thrown on the front feet and more 

 strain is thrown upon muscles in holding the horse in this condition. 

 Such a horse is likely to pound out his front feet too quickly. On 

 the other hand, if his hind feet are too far under him, too much of 

 the W'Cight is thrown upon the hind members and too much force is 

 required of the hocks. Consequently, the horse is liable to injury 

 at this point. Ordinarily, five-ninths the w^eight of a horse is car- 



