“On analyzing the experiments, both at Portsmouth, and Shoebury Ness, it appears that the flight of the ordinary solid shot was the most true, the lateral deflections being frequently but one-half, sometimes one-third, or one-fourth only of the deflections of the excentric shot; that these last deflections were always in the direction in which the centres of gravity of the shot were placed in the gun; and that the increases, or diminutions of range caused by the vertical deviations were produced respectively, as the centres of gravity of the shot were placed upwards, or downwards. It appears, also, that the lateral deviations, though in general constant in direction, were very variable in amount. The results above stated prove decisively the correctness of the deductions from theory, and of the practical maxim, that errors in sphericity and homogeneity in a shot are causes of its deviation from a correct path; and it follows that spherical and homogeneous projectiles, being the most simple, and quite indifferent to the position in which they are placed in the gun and rolled home, as well as to that in which they pass through the atmosphere, are decidedly to be preferred to the others.
“The results of these very curious, and instructive experiments fully explain the extraordinary anomalies, as they have hitherto been considered, in length of range, and in the lateral deviations: these have been attributed to changes in the state of the air, or the direction of the wind, to differences in the strength of the gunpowder, and to inequalities in the degrees of windage. All these causes are, no doubt, productive of errors in practice; but it is now clear that those errors are chiefly occasioned by the excentricity, and non-homogeneity of the shot, and the accidental positions of the centre of gravity of the projectile with respect to the axis of the bore.
“The whole of these experiments furnish decisive proof of the necessity of paying the most scrupulous attention to the figure, and homogeneity of solid shot, and the concentricity of shells; and they exhibit the remarkable fact, that a very considerable increase of range may be obtained without an increase in the charge, or elevation of the gun.”
Resistance of iron plates, oak plank, &c., against musketry, canister, grape shot, hollow, and solid shot.
“From experiments in November, 1849, the following results were obtained:—
“Marine percussion musket—Charge, 4½ drams; distance, 40 yards.
| “Iron plates, | ⅛ | inch | } | All passed through. |
| Oak plank, | 1 | ” | } | |
| Iron plates, | 2/8 | ” | } | 4 in 6 passed through. |
| Oak plank, | 2 | ” | } | |
| Iron plates, | ⅜ | ” | } | Both musket proof. |
| Oak plank, | 3 | ” | } | |
| Canister—Charge, 6 lb.; distance, 100 yards. | ||||
| Iron plates, | ⅜ | inch | } | Passed through. |
| Oak plank, | 3 | ” | } | |
| Iron plates, | 4/8 | ” | } | Canister proof. |
| Oak plank, | 4 | ” | } | |
| Grape—Charge, 6 lb.; distance, 200 yards. | ||||
| Iron plates, | 4/8 | inch | } | |
| ” | ⅝ | ” | } | All passed through. |
| ” | 6/8 | ” | } | |
| Oak plank, | 4 | inch | } | All passed through. |
| ” | 5 | ” | } | |
| ” | 6 | ” | Generally passed through. | |
“Experiments were made in June, 1850, against two sections of the ‘Simoom,’ ⅝ inch thick, placed 35 feet apart; the guns, and charges were those used in all steam vessels. The result made evident that two, or three shot, or sometimes even a single one, striking near the water-line of an iron vessel, must endanger the ship. Another most serious evil is, that the shot breaks, on striking, into innumerable pieces, which pass into the ship with such force, as to range afterwards to a distance of 400 or 500 yards; and that the effect on men at their quarters would be more destructive than canister shot, supposing them to pass through a ship’s side; as when the plates are only ⅜ inch thick.
“Experiments were made in July, 1850, against an iron section similar to the ‘Simoom;’ it was filled in and made solid with 5½ inch oak timber between the iron ribs, and 4½ inch oak planking above the water-ways, which were 1 foot thick, and with 3 inch fir above the portsills; these were strongly secured to the iron plates by bolts. The results were as follows:—The holes made by the shot were not so irregular as on the former occasion, but as clear and open; all parts of the shot passed right through the iron and timber, and then split, and spread abroad with considerable velocity. With low charges, the shot did not split into so many pieces as before. With high charges, the splinters from the shot were as numerous and as severe as before, with the addition, in this, and the former case, of the evil to which other vessels are subject—that of the splinters torn from the timbers.