The elevation which gives the greatest range on a descent, is equal to half the complement of the descent.
14. The depths penetrated by balls of the same size into wood, with different velocities, or charges, are nearly as the squares of the velocities. Balls of different sizes will penetrate to depths proportionate to their diameters; therefore a greater ball will not only make a larger hole, but will also penetrate farther than a small one with the same velocity.
15. By experiments at a mean range, it has been ascertained that in common earth, dug up and well rammed, a musket ball buries itself nearly 1½ foot; a 6-pounder from 3½ feet to 4½ feet; 9-pounder from 6½ feet to 7 feet; 12-pounder from 8½ feet to 10 feet; 18, and 24-pounders from 11½ feet to 13 feet.
THEORY, AND PRACTICE OF GUNNERY,
APPLICABLE ESPECIALLY TO THE SERVICE OF NAVAL ORDNANCE.[29]
Double Shotting.
“Double shotting may be used with all 32-pounder guns above those of 32 cwt., at distances not exceeding 400 or 500 yards; but the most efficient practice with two shot is at 300 yards. The 32-pounders of 32 cwt. and 25 cwt. should not, however, be so used beyond 200 and 250 yards.
“With double loadings of round shot and grape, when the shot is put in first, the projectiles range more together than when the reverse process is used; such loading requires, however, more elevation to be given to the gun than when single shot are used, on account of the grape shot impeding the flight of the round shot. A double load of grape from the same gun ranges tolerably well together for 300 yards. With a double load of case shot, even with half a degree more elevation than when a single load is used, a great many balls will not range above 100 yards to the first graze; within this extent they lose much of their velocity, and few reach an object at 200 yards. A 32-pounder gun of 56, or of 50 cwt., double shotted with charges of 6 lb., requires at 400 yards 1½ degree of elevation; at 300 yards 1 degree; and at 200 yards half a degree; and, in general, half a degree must be added, with any double loading, to the elevation required with single shot.
“For round, and grape, at 400 yards, there is required 1½ degree of elevation; and at 200 yards half a degree. These projectiles range well together at a target, but they should not be used at a greater distance than 150 yards on account of their dispersion, and the differences of their striking velocities, and penetrating forces.
“With a single load of grape at 400 yards, the elevation required is 1 degree, a full charge of powder being used. With a double load of grape at 400 yards, and the reduced charge, the elevation required is 3½ degrees; at that distance, however, double grape scatters so much as to make very bad practice.”