THE SHOE. 57 



fatigue it induces causes it to "be less durable, in propor- 

 tion to the quantity of iron. This is accounted for by 

 the manner in which the fatigued limbs drag their heavy 

 load along the surface of the ground. Heavy shoes also 

 require more and larger nails to attach them securely to 

 the hoof, and this in itself is an evil of no trifling magni- 

 tude, as we shall see presently. 



The shoe, besides being heavy, may offer other serious 

 defects. It may be very uneven on its upper bearing sur- 

 face — that on which the hoof rests ; it may have too 

 many clips, and these not well formed or situated ; its 

 ground surface may be unequal ; or the holes for the nails 

 may be badly placed, and improperly stamped. 



An uneven upper surface is apt to produce lameness, 

 from the undue pressure it occasions on limited parts of 

 the hoof, and through these to the corresponding living 

 textures ; or it may cause the wall of the hoof to split, 

 etc. 



Nails badly placed and improperly stamped are a pro- 

 lific source of injury to the foot, and the same may be 

 said of mal-formed or wrongly-situated clips ; and much 

 evil results from the ground-face of the shoe being higher 

 at one part than another. This inequality is in nearly 

 every case due to the presence of what are termed " cal- 

 , kins " at the extremities of the branches of the shoe ; or 

 to one side of the plate being thicker than the other. 



Calkins. — Calkins are injurious to the limb in propor- 

 tion to their height. When smallest they are an evil, as 

 they have a tendency, in raising the back part of the foot 

 higher than the front, to alter the natural direction of the 

 limb, and throw undue strain on the fore part. Intended 

 to prevent slipping, their use in this respect is but tem- 

 porary, unless they are made high and thick ; when their 

 unfavorable influence on the limb and foot is increased. 

 Added to this, from their throwing so much of the weight 



