i6o THE TRUNK. 



legs are apart, the less rigid will be the connection between 

 them, and the less efficiently will they work together. When 

 speaking of the depth of a horse's body, I refer to its depth 

 at the lowest point of its back (Fig. ii). If an animal 

 shows a good measurement at this part, he is almost certain 

 to possess fair substance of body. The measurement from 

 withers to brisket is very fallacious ; for it is not alone 

 affected by the height of the withers themselves, but it also 

 affords hardly any indication of the nature of the " centre- 

 piece " of the body. Many horses which are very light in 

 their loins and back ribs have good depth from withers to 

 brisket, as in Fig. 268. In different horses, the length of the 

 body varies from about 2 . 4 to 2.8 times its depth. 



Chest and Ribs. — Although the heart, as well as the 

 lungs, is contained in the chest, I shall not consider it here , 

 for I can offer no clue as to its action from the consideration 

 of the conformation of the chest, which is influenced chiefly 

 by the shape, size and setting-on of the ribs. The points 

 which we should seek for in the ribs of the horse, in order to 

 obtain the best possible breathing power, are — 



I. Convexity or roundness of ribs (''barrel") behind the 

 shoulders. 



2 Good length of ribs. 



3 Ribs well inclined to the rear. 



I may explain that the convexity of a curve may be 

 measured by the proportion which its height {c d, Fig. 261 

 or Fig. 262) bears to the length of its chord a b. Thus, if c d 



Fig 261.— Semicircle Fig 262— Apc of Circle 



is equal to i a 6 in Fig. 261, and equal to I a 5 in Fig. 262, 

 the curve a c 3 will be three times as convex in the former as 

 in the latter. 



