THE ANGLE OF TRACTION, ETC. 223 



trace may and very often does act altogether obliquely 

 on the collar, and then produces that grinding motion 

 which is sure to get up a raw. To have recourse once 

 more to our old familiar illustration : if the pull on the 

 -collar occurs in the direction T, Fig. 17, the lower part 

 of the collar is pulled up against the horse's windpipe, 

 and chokes him more or less ; and if in the direction 

 W, in which the pole-chains act, then it wounds the 

 withers, and in both cases has a grinding action ; 

 therefore the line that lies farthest away from these 

 two objectionable directions is the least likely to cause 

 injury, and this is the perpendicular to the collar 

 recommended in the 'Artillerist's Manual,' and is also, 

 as we have seen, the one most nearly parallel to the 

 line of propulsion through the horse's hind legs. 



Very injudicious arrangements of the collar and 

 traces occur most frequently perhaps with carts and 

 other two-wheeled vehicles. Having the misfortune 

 to live in a street leading to the coal-wharf of a railway, 

 we have specimens of this sort of thing daily and 

 hourly before our eyes, but the bakers and doctors and 

 fat farmers, reinforced now and then by a few millers 

 and brewers, are also well represented. Like so many 

 other absurdities, this too originates in the exaggerated, 

 and therefore wrong, application of a really correct and 

 useful principle. There can be no doubt that in two- 

 wheeled carriages or carts the load ought to be balanced 

 on the axle-tree, so as that a minimum of pressure 

 should fall on the horse's back, because by this arrange- 

 ment the entire power of the animal is reserved for 

 traction ; and as the most useful way of employing a 

 horse's power is in draught, and the worst is in carrying 

 a load, the method now universally adopted of taking 



