THE AXGLE OF TEACTIOX, ETC. 223 



drawn from the middle point of the anterior edge of 

 the shoulder-blade, where the collar rests, and at right 

 angles to it, we see that this line would, if prolonged, 

 go away to the rear just at the horse's hocks to 

 the point R, where it forms only a very small angle 

 with the line R S (fig. 4) ; and it is quite evident that 

 when the horse, in leaning forward to draw, lowers his 

 forehand, the two lines will coincide very nearly ; or in 

 other words, the direction in which the propelling- 

 force of the hind legs is effected will be exactly con- 

 trary to that in which the resistance to the traction 

 occurs, whereas with the horizontal trace it will form a 

 considerable angle with it at the point of attachment 

 to the collar. 



We have therefore the weight of evidence, both 

 practical and theoretical, in favour of the trace l/cing 

 attached to the middle of the collar, and at right angles 

 with it : and if this were not so, a horse with a bad, 

 that is to say a short straight shoulder, ought to be 

 better for draught than one with a long slanting one ; 

 for the horizontal trace is much more easily attained 

 with the former than with the latter. 



In forming a final opinion on this matter of the 

 angle of traction, the fact should never be lost sight of 

 that a high wheel, which always reduces this angle, 

 may, on account of the great mechanical advantages 

 inherent in itself, make a perfectly horizontal trace, or 

 even one inclined the wrong way to the horizon,* ap- 

 pear to be more advantageous than one that works at 

 right angles to the horse's shoulder. This, however, 



"■ As for iustauce, when a sraall horse is put into a gig intend- 

 ed for a big one. Vide Mi-. Pickwick's discourse ^vith the cab- 

 man, that ended so disastrously for that gentleman. 



