NOTES ON SHOEING OF HORSES. 15 



perpendicularly will sustain a much greater weight 

 without yielding, than it will, if placed horizontally. 



Besides this difference in position, the fibres of 

 the sole are in themselves much less substantial 

 than those of the crust. 



Wliilst, then, from its construction it is evident 

 that the insensitive sole is not intended to bear 

 weight, it is also most important, on account of its 

 position, that no undue weight should be put on 

 it. If pressure is thrown on the insensitive sole, 

 the sensitive layer above must suffer compression 

 between the hard and unyielding coffin-bone above 

 and its own insensitive layer below. 



Again, the sole is recessed or concave. It is a 

 rule in nature that recessed parts are never intended 

 to bear weight or to sustain pressure. 



At the junction, however, of the sole with the 

 crust, the fibres of both are interlaced for the 

 breadth of about a quarter of an inch. This inter- 

 mediate substance possesses considerable strength, 

 and is capable of bearing both weight and pressure. 

 It will be referred to again, when we come to consider 

 the proper width of shoes. (Vid. inf., par. 32.) 



The sensitive, or vascular and organized, sole lies 

 immediately above the insensitive, and is protected 

 by it from external injuries, such as blows, &c. 

 The insensitive sole can only perform this function 

 effectually, when preserved in its entirety, sound 

 and unpared. 



