15 
to be fired horizontally from a common gun. 
for the range at which naval actions are generally fought, but 
the object in view is to make them available to the full extent 
of their range, and I shall accordingly point out the means 
by which I conceive this object may be very much facilitated. 
Considerable improvement may, I think, yet be made in the 
mode of casting them; for although the gentlemen of the 
Carron Company have bestowed great pains on those that were 
cast by them, it seldom happens in matters of this kind, 
that the most simple process is discovered in the first instance. 
They may also be turned in a lathe, by means of machinery, 
which their shape will allow them to be with great facility, 
and thus rendered perfectly cylindrical, and of the same size. 
In the course of the experiments that have been made, the 
shell has also been greatly improved by an addition to the 
length originally given to it. This might, a priori, have been 
expected, as its weight is increased, without increasing the 
resistance of the air ; and by this alteration its range is found 
to be increased also. The accuracy of fire is also found to be 
greater, as the angle of departure is diminished. Hence, 
greater 'accuracy of fire may be expected from heavy guns 
than from light ones, the sides of the shells in the former 
being much longer than in the latter, while the windage in 
both is equal. The following construction of a shell for a 
9 pounder, I consider as the best, so far as the experiments 
made will allow me to determine. In these proportions, 
the length of the sides is increased half an inch beyond 
that of any yet used, and the twist is reduced from 55 to 
72 inches. 
