252 MANUAL OF MODERN FARRIERT. 



as the ass, above all other animals, for the service of man. 

 In short, had the hoof of the horse been cleft, he would 

 have been incapacitated for many of the useful departments 

 of his employment ; and a correct knowledge of the struc- 

 ture of every part of the foot is indispensably necessary to 

 render us scientific overseers of the farrier's art. 



The crust is that portion which reaches from the termi- 

 nation of the hair to the ground. Its depth is greatest in 

 front, and is denominated the toe ; it is more shallow at the 

 sides, which are called the quarters, and still less behind, 

 which is termed the heel. When the sole is placed on the 

 ground, the front exhibits an angle of about forty-five 

 degrees, difiering, however, considerably in many horses to 

 the extent of the angle. But a healthy and well-formed hoof 

 very nearly approaches what we have stated, that is, a fourth 

 part of a semicircle. With a greater degree of obliquity, it 

 is said the crust has " fallen in,'' and when the sole is too 

 flat, and is said to be pumiced, or convex ; and if the front be 

 more upright than the above angle, it is the proof of a con- 

 tracted foot with the sole too concave. When the crust is 

 deep at the heel, it is a foot liable to contraction, thrush, 

 sand-crack, and inflammation. The pastern will be found 

 too upright, and the horse will have a bad and unpleasant 

 action. If, on the other hand, the crust diminishes too 

 rapidly from front to back, and the heels are low, this 

 is always accompanied by too great obliquity of the pastern, 

 producing a weakness in the joint, and liability to sprain of 

 the back sinew, described at page 117. The foot itself will 

 be weak, and have a general tendency to that hidden lame- 

 ness called "the navicular-joint disease," particularized at 

 page 165. 



The general thickness of the crust in front is somewhat 

 more than half-an-inch, becoming gradually thinner towards 



