6o MECHANISM OF DRAUGHT, 



the centre of gravity with leference to the position of the base of support, is 

 influencedj first, by the degree of slope which the foie leg makes with the 

 ground immediately before it quits it, and before the other fore leg is brought 

 down ; and, second, by the loweiing of the head and neck. I need hardly 

 say that horses with toe-pieces to their fore shoes can, while retaining their 

 foothold, biing the centie of giavity faither beyond the base of support, by 

 the slope of the fore leg which rests on the ground, than they could do with 

 flat shoes ; supposing, of couise, that the surface of the ground was not 

 abnormally smooth and hard, like wood or asphalt. From the foregoing 

 considerations we may draw, with respect to cart-horses that are required to 

 exert their strength to the utmost, the following deductions, which are fairly 

 self-evident to practical men. 



I. Bodily weight, especially in the fore hand, is an advantage m draught; 



Fig. 42.— Mechanism of Draught. (From Colm's Physiologk Comparie?^ 



for the greater it is, the more effective will be the push against the collar 

 caused by the centre of gravity falling beyond the base of support. Agreeably 

 to this fact, the experienced driver of a heavily-laden two- wheeled cart will 

 endeavour to place a fair share of the burden on the animal's back, so that 

 the horse may pull to the best advantage. The experiment of a man 

 succeeding in pulling along a stronger man than himself, by trying to do so, 

 while carrying a heavy weight on his back, is another familiar instance of 

 this principle. The gain in power from increased weight on the fore hand is, 

 also, well illustrated by the practice, which is not very uncommon among 

 drivers of one-horse carts, of the driver mounting his animal and getting well 

 forward on its back, when he finds that it is unable to pull its load up a hill 



