474 CHArTEii 63. 



the weight of the horse ; and a shoe of the usual width (one inch) flat 

 towards the sole would press unduly on the sole, unless the pressure was 

 obviated " by seating out " (A, Fig. 8). 



" Seating out " is a practice wrong in itself, but generally rendered 

 necessary by another bad practice. There need, however, be no fear of 

 undue pressure on the sole, if the crust be preserved whole, sound, and 

 tough. 



Again, it is obvious that the superincumbent weight is more diffused 

 by gaining a wider bearing for the shoe ; and hence those diseases which 

 arise from undue concussion are less likely to occur. 



965. Under or ground surface of the Shoe. 



The under or ground surface of the shoe should be concave (A, Fig. 9). 

 This is the form in which nature has moulded the horse's foot, and wo 

 cannot do wrong in following it. I am not aware of any objection which 

 can be urged against it. This form, it is true, is not adopted in the 

 shoe in ordinary use ; but this arises not from any objection in theory, 

 so far as I am aware, but from the simple fact that inasmuch as, for the 

 reasons given above, it is usual tq seat out the upper surface, it is im- 

 possible also to seat out the lower surface. A double seating out would 

 render the shoe so thin that it would be liable to break. 



A concave ground-surface has a great practical advantage, inasmuch as 

 the shoe gets a much greater hold on the ground, and the horse is there- 

 fore less liable to slip, or pick up stones. 



966. Length of the Shoe. Heels of the Shoe. 



The length of the shoe is determined by the length of the crust. The 

 shoe must- be the exact and full length of the crust. Nature, in fact, in 

 all cases points out the proper length of the shoe by the termination of 

 the crust. If shoes are made shorter than the crust, their heels or " ends 

 of their branches " will be apt to press upon and dig into the seat of the 

 corn. If, on the other hand, the shoes are longer than the crust, tne 

 hind shoes may catch in the heels of the fore-shoes and pull them off. 



An objection is sometimes raised to fore-shoes being made the full 

 length of the crust, on account of a fear lest the hind shoes should catch 

 in them. This accident, however, is not likely to occur where the shoes 

 are not longer than the crust. The possibility of it will be prevented by 

 sloping off the heels of the fore-shoes in the direction of the fibres of the 

 crust (fig. 9), and again by sloping off the inner or posterior edge of the 

 toe of the hind shoes. (See Over-reach, Chap. 65, par. 1002.) 



967. Fitting of the Shoe. 



The crust having been lowered by the rasp, aided as little as possible 

 by the knife, and rendered smooth by the rasp, and its sharp edge having 

 been rounded off, the shoe must then be so fitted that its outer edge 

 corresponds exactly with the crust. It must not be smaller than the 



