some fractions of an inch determines considerable oscillations of the weight.
A just relation may be said to exist between the height of the toe and that of the heels, when the latter is about two-thirds that of the former. This is the natural form; though, through improper shoeing, and perhaps defective organization, it may vary. To lower the heels more than the toe, is to lengthen the foot; and to shorten the toe, and leave the heels untouched, is to raise the latter.
The amount of horn to be removed from the crust, as well as the manner of removing it, is another important consideration. As before mentioned, the heels usually wear themselves tolerably low against the extremities of the branches of the shoe; but where the latter has been firmly fixed to the crust, this up-and-down friction does not take place, and the posterior parts of the foot are proportionally long. As a general rule, however, the heels require little or no alteration, and the toe needs shortening. With the hoofs of saddle or carriage horses, this shortening is best and most safely accomplished with the rasp. Heavy draught-horses, whose hoofs may have grown excessively long, and which have more horn to spare, are oftener trimmed with the toe-knife.
If the horse is to be shod with a shoe reaching to the points of the heels, the horn of the wall at this region, if necessary, is to be removed to the degree prescribed above. Under all circumstances, every fragment of loose horn incapable of supporting the shoe, ought to be taken away, so as to reach sound material. This may be done by passing the rasp evenly along the ground-surface of the
