“In August, 1850, an iron section similar to the ‘Simoom’ was prepared with a covering of fir plank on the outside, of the thickness of 2, 3, and 4 inches, in different parts. The result of this experiment was similar to the last, when the wood was on the inside; with the exception of the splinters from the wood. The holes made by the shot were regular, of the full size of the shot, and open; every shot split on passing through—those between the ribs into a few pieces only, those that struck on the ribs into a great number; in both cases, when combined with the splinters of the iron side, the effect must prove highly destructive.
“A comparison as to the effect of shot on iron, and timber, was made by firing 8-inch hollow shot, and 32-pound solid shot, at a butt built for experimental shell-firing, with timber having 6-inch plank on the outside, and 4-inch within; the result was, that the splinters from the wood were trifling when compared with those from the iron.
“The general result of all the foregoing, and consecutive experiments for the same purpose, clearly demonstrates that the destructive effects of the impacts of shot on iron cannot be prevented. If the iron sides are of the thickness required to give adequate strength to the ship (⅝, or at least 4/8 of an inch), the shot will be broken by the impact; if the iron plates be thin enough to let the shot pass into the ship without breaking, the vessel will be deficient in strength; the shot will do its work, particularly in oblique or raking fire, more effectively than its splinters, and, in passing out, make apertures more difficult to plug or stop, than in passing in. When a clean hole is made by a shot penetrating an iron plate, the whole of the disc struck out by the shot is broken into numerous small pieces, which are driven into the ship with very destructive effects; and if the plate be so thick (viz., upwards of 4/8 of an inch) as to cause the shot to break on striking, the fragments will nevertheless pass into the ship, as in the case of a percussion, or concussion shell, and so produce a terrific compound effect by the fragments of both.
“The expedient of combining wood, and iron, either by substituting timber for the iron ribs, or the reverse, outside planking for the iron plates—makes the matter worse. The pieces of ribs struck off, sometimes of great length, pass on with the shot, to produce more extensive ravages elsewhere.”
NAVAL GUNNERY.
“In firing into masses of timber, or any solid substance, that velocity which can but just penetrate will occasion the greatest shake, and tear off the greatest number of and largest splinters; consequently, in close actions, shot discharged with the full quantity of powder tear off fewer splinters than balls fired from the same nature of guns with reduced charges.
“In naval actions, shot intended to take effect upon the hull of an enemy should rather be discharged with a falling than with a rising side; but such pieces as may be appointed specially to act against the masts and rigging should be fired, on the contrary, with the rising motion, the aim being taken low.
“In all close actions, the great object should be to strike as often as possible the enemy’s hull. One or two 24-lb. shot taking effect just below the water-line, and perhaps perforating both sides of a small vessel, will in general either force her to surrender, or send her to the bottom; and such an injury is much more likely to be occasioned by firing with a falling than with a rising side.
“To estimate the distance between vessels.[31]
“Measure with a sextant, or quadrant, the angular height of the enemy’s mast, and by referring to Table B, the corresponding distance may be taken out.