The advantage of large cannon over those of a smaller bore is so generally acknowledged, that a particular discussion of it might perhaps be spared. * * *
“The most important advantage of heavy bullets is this, that with the same velocity they break holes out in all solid bodies in a greater proportion than their weight; that is, for instance, a twenty-four pound shot will, with the same velocity, break out a hole in any wall, rampart, or solid beam, in which it lodges, above eight times larger than will be made by a three pound shot; for its diameter being double, it will make a superficial fracture above four times as great as the three-pounder, (more of a smaller hole being closed up by the springing of the solid body than of a great one) and it will penetrate to more than twice the depth; by this means the firmest walls of masonry are easily cut through their whole substance by heavy shot, which could never be affected by those of a smaller caliber; and in ships the strongest beams and masts are hereby fractured, which a very great number of small bullets would scarcely injure.
“To this last advantage of large cannon, which is indeed a capital one, there must be that of carrying the weight of their bullet in grape or lead shot, and thereby annoying the enemy more effectually than could be done by ten times the number of small pieces.
“These are the principal advantages of large cannon, and hence it is no wonder that those entrusted with the care of the British navy have always endeavoured to arm all ships with the largest cannon they could with safety bear; and indeed, within these last hundred years, great improvements have been made on this head, by reducing the weight of many of the species of cannon, and thereby enabling the same ships to carry guns of a larger bore: and, very lately, the six pounders in some of the smaller ships have been changed for nine pounders of a larger fabric than usual, which hath been justly esteemed a very great addition, to the strength of those ships.
“The importance then of allotting to all ships the largest cannon they can with safety bear being granted, it remains to shew on what foundation a change is proposed to be made in the fabric of all pieces from the present eighteen pounders downwards, so that they may be changed for others of the same, or less weight, but of a larger bore. This proposition turns on the following considerations.—The species of cannon proper for each ship is limited by the weight of the pieces; and when the charge and effort of the bullet are assigned, this weight in each species is, or ought to be determined by the following circumstances;
That they shall not be in danger of bursting;
That they shall not recoil too boisterously;
And that they shall not heat too much in frequent firing.
“All this is to be done by a proper quantity of metal properly disposed; and when the pieces are secured from these accidents, all additional weight of metal, is not only useless but prejudicial.
“Now what dimensions and weight of metal are more than sufficient for these purposes, we may learn from the present practice of the navy, in the fabric of the thirty-two pounders, the heaviest guns in common use; these are made to weigh (if the author’s information be right) from fifty-two to fifty-three hundred weight; that is somewhat less than an hundred and two-thirds for each pound of bullet.