258 
ON ONE-SIDED NAILING. 
No. 1. No. 2. 
depends. The writer says that it is owing* to this “ reciprocal 
support” that the nails near the heels contribute most to the 
shoes' security. Now I would explain the circumstance very 
differently: I consider when a horse thrown a shoe, the displace¬ 
ment goes on on the principle of the lever, of which the toe is 
the fulcrum; the heels the pow T er that displaces (and which is 
greater or less according to the weight of the heels, and the 
velocity with which the foot is carried through the air), and the 
nails, of course, the objects to be raised. The nails nearest the 
heels must be the ones first moved, and in proportion to the 
proximity of these nails to the heels is the difficulty of throw ing 
the shoe : but each half of the shoe must act as a separate lever ; 
and I should imagine (supposing that throwing the shoe were 
desirable) that both levers should act alike, and with recipro¬ 
city ; which cannot be the case with side-nailing, as the lever on 
the inside would act with double the advantage of that on the 
outside. To exemplify the subject, let us suppose two men 
moving a heavy w 7 eight by means of levers (of that class where 
the object to be moved is between the power and the fulcrum) ; 
it w ould be necessary for these levers to be of the same length 
and to be applied in a similar manner; for if one of them w 7 ere to 
use a shorter stick, or to place it to disadvantage (by putting 
it too much under the object to be moved), or to use much less 
exertion, he would, in a great measure, render nugatory the 
other man's labour. Thus it is w ith Mr. Turner’s shoe; the security 
is greater on the outside and less on the inside than the common 
shoe: but this very inequality tends rather to its general safety 
than otherwise. 
But to proceed: has this reciprocal support really any thing 
to do w T ith the security of the shoe ? If the shoe w ere a plate of 
iron covering the whole of the bottom of the foot, then it cer¬ 
tainly would; but as it is simply a ring going round its lower cir- 
* cumference, it is reasoning from analogy (with a vengeance) to 
suppose, that it can possibly be governed or guided by any 
imaginary lines drawn from one nail hole to another. The argu- 
