138 
The Principles of Horse-Shoeing. 
The fore foot, when well formed, is nearly, if not quite circular ; 
the hind foot is somewhat oval, the frog smaller, and the sole more 
concave. 
When the hoof is shod, the wall is not exposed to wear, and 
therefore would grow to an indefinite, and consequently most 
inconvenient, length if the shoe should chance to be retained 
too long, and the excess in growth of horn not removed. The 
sole and frog, on the contrary, never cause inconvenience, as 
their growth is limited. 
What is required in shoeing, then, is merely protection from 
undue wear, with the least possible interference with, or dis- 
turbance to the functions of, the foot and limb. The excess in 
length of the wall must be removed at frequent intervals — 
between a fortnight and a month, according to the activity of 
growth ; but the sole and frog, if healthy, should not be dis- 
turbed. Not a grain of iron more than is absolutely neces- 
sary should be allowed as a protection ; and this question of 
weight of shoes is an important one, especially with horses 
which are compelled to travel beyond a walk. There are 
no muscles below the knee and hock, and those which are 
chiefly concerned in the movements of the limb arise high 
up, and act upon short levers. An ounce weight at the shoulder 
or stifle, therefore, progressively and rapidly increases, until at 
the foot it has become equal to several pounds. Therefore it is that 
a shoe six or twelve ounces heavier than is absolutely necessary 
to protect the wall from wear, occasions a great waste of 
muscular power of the limb, and consequent fatigue. If we 
consider the rapidity with which the weight increases from the 
shoulder or hip towards the foot, the number of steps a horse takes 
in a journey of a few hours, and that there are four feet so sur- 
charged, we shall gain some notion of the many needless tons 
which the animal has been compelled to carry, and the strain 
thrown upon foot and limb — a strain they were never intended, 
and are not adapted by Nature, to bear. All shoes should, then, 
be as light as may be compatible with the wear demanded from 
them. 
For all horses, except, perhaps, the heaviest animals employed 
in drays and heavy waggons, the lower or ground face of the 
shoes should be concave, and the upper or foot surface plane, or 
nearly so. They should be retained l)y the smallest number 
of nails possible — six or seven in the fore shoes, and eight in 
the hind shoes. Calks should never be employed. With the 
heaviest horses — the dray or waggon animals — it may be ad- 
vantageous to have toe and heel calks, to afford secure foothold. 
The procedure in shoeing is simple in the extreme. When 
the old shoe is removed from the hoof, nothing more is required 
