134 ENGLAND S HORSES, 



the hind leg in coming up to the proper point or resistance, and 

 consequently the greater extent of ground covered at each stride ; 

 and as the velocity and stride are thus increased, the body, from 

 the greater obliquity of its supporters, will approach nearer the 

 earth ; hence we see the racer, in full speed, skim along with his 

 belly very contiguous to the ground, bringing up his hind legs at 

 each stride, so as to catch the flying centre of gravity, by an effort 

 which may be said to mark the utmost limit of their contractile 

 exertion. 



In the centre of gravity, therefore, whether stationary as in the 

 horse trying to put himself in motion, or progressive, as when he 

 is propelled both by momentum and by successive accessions of 

 muscular energy from behind, we have the proper limit of con- 

 traction, of which we have been in search. So far, therefore, we 

 conclude, 1st, that the propelling powers reside in the hind legs 

 and haunches : 2nd, that these powers are in proportion to the 

 amount of contraction and extension of which the parts are 

 capable ; and 3rd, that the limits within which they are exercised 

 are the extremity of the outstretched limb, on the one hand, and 

 the point immediately below the centre of gravity — stationary or 

 progressive — on the other. 



If by extravagant action those limits be overpassed in front, the 

 consequence, as I have remarked, will be a certain degree of em- 

 barrassment, the point of resistance being in advance of the weight ; 

 if they be overpassed behind, injury to the hock or haunch will be 

 the result of that excessive extension ; but while straining and 

 embarrassment thus attend on ever}'- excess of action beyond either 

 limit, they will also attend, in a greater or less degree, on every 

 falling short of the same bounds, though they will be chiefly in the 

 case oi deficient contraction. 



Deficient contraction exists whenever the hind foot fails to over- 

 take the advancing centre of gravity ; the weight is then in 

 advance of the point of resistance, and the horse, in urging it 

 forward, labours under the same disadvantage as would be 

 experienced by the man who should attempt to throw the heavy 

 slioulder stone from a point in advance of his foot. Both cases 



