26 THE ART OF HORSE-SHOEING. 



to take a bearing for whicli it is not adapted. There is- 

 oiily one part of the sole which should act as a bearing- 

 surface, viz., that outer border which is firmly joined to 

 the wall. This part — the abutment of the arch — is des- 

 tined by nature to take a bearing, and through it the 

 vhole of the sole supports its share of weight. 



The frog takes a bearing on the ground, but it has a 

 veight-sustaining function quite secondary to the harder 

 and firmer parts of the hoof. It is formed of a softer 

 horn, and it has above it only soft tissues which permit 

 yielding. The frog, then, when weight is placed upon it- 

 by the standing horse, recedes from presburo and leaves 

 the heels (wall and bars) to sustain the primary weight. 

 "Wall, sole and frog, each take their share in supporting 

 weight, but this function is distributed over them in dif- 

 ferent degrees, and it is fulfilled by each in a varying 

 manner. During progression, the foot is repeatedly 

 raised from and replaced on the ground. It has not 

 only to support weight, but to sustain the effects of con- 

 tact with the ground at each step, and the effects of 

 being the point of resistance when the body is carried 

 forward and the foot is again raised from the ground. 



Wliat part of the- foot comes first to the ground? 

 Many different answers have been given to this ques- 

 tion. It has been said by some that the toe first touches 

 the ground; by others, that the foot is laid fiat down; 

 and by a few, that the heel is the first ])art to come iii 

 contact v/ith the ground. Fortunately, it is not now 

 necessary to argue this question on a i)urely theoretical 

 basis. Instantaneous photograpy has shown that ou 

 level ground, at all paces, the horse touches the ground 

 first with the heel. This fact gives significance to tho 

 structural differences we find between the front and back 

 portions of tho foot. At the back part of the foot, we 

 have the wall thinner than elsewhere, we have tho 

 moveable and elastic frog, tho lateral cartilages, and tho 

 frog-pad. We have, in fact, a whole series of soft and 

 elastic structures so arranged as to provide a mechanism 

 best adapted to meet shock and to avoid concussion. 

 "Whilst drawing heavy loads, or ascending or descending: 



