210 
NAILING HORSESHOES ON. 
results by the formation of two (or, if required, more) centres. 
The diagrams underneath may serve to illustrate my meaning:— 
In these examples, A, A and B, B reciprocally support each 
other: what tends to disturb one point is opposed by the other, 
so that the resistance is always double ; and in the case of the 
circle more than double, because each distinct part receives its 
strength from the integrity of the whole. 
Let us apply these geometric principles to the practice of nail¬ 
ing shoes upon horses’ feet. The figure of the hoof is circular, 
or inclines more or less to an oval: let us see, then, how the nails, 
placed in the ordinary mode, tend to the support of one another. 
An inspection of this diagram will shew the points and direc¬ 
tions in which the nails, according to the ordinary method of 
placing them, mutually support each other. It likewise de¬ 
monstrates that the nails near the heels yield more support to 
the shoe than those near the toe ; which latter, were they placed 
yet more in front, would be unsupported by counter-holds 
altogether. 
Let us, in the second place, test by this principle Mr. Turner’s 
method of proceeding. The figure subjoined may serve to ex¬ 
plain the innovation in nailing he proposes:— . 
