92 THE HUNTER. 



other words, the length of this bone, will two 

 purposes be effected. The line of direction will be 

 more advantageous, for it will be nearer to a per- 

 pendicular ; and the arm of the lever to which the 

 power is applied will be lengthened, and mechanical 

 advantage will be gained to an almost incredible 

 extent. Suppose this bone of the hock to be three 

 inches in length, the joint formed by the tibia and 

 the astragalus is evidently the centre of motion, 

 and the weight concentrated about the middle of 

 the shank is the obstacle to be overcome. If the 

 weight be four times as far from the centre of mo- 

 tion as the power, a force equal to four times the 

 weight would raise it. It is, however, here to be 

 remembered, that it is not merely the weight of 

 the leg which is to be raised, but the weight of the 

 horse, for the time resting upon the leg, and that 

 weight to be propelled or driven forward. At what 

 shall we calculate this ? We may fairly suppose 

 that the muscles, whose tendons are inserted into 

 the point of the hock, exert an energy equal to 4000 

 lb. Let us further suppose, that an inch is added 

 to the point of the hock, which will be an addition 

 of one-third to its length : a muscular power of less 

 than 3000 lb. will now effect the same purpose. 

 The slightest lengthening, therefore, of the point 

 of the hock will make an exceedingly great differ- 

 ence in the muscular energy by w^hich the joint is 

 moved, and a difference that will wonderfully tell 

 in a long day's work. On this account, the depth 

 of the hock, or the length of the bone of which we 

 are speaking, is a point of the greatest importance. 



