The proportions of all guns to shot, will be found below; and in looking at this table, it will scarce be conceivable how such light guns can project such heavy shot.
Comparative Weights of Guns and Shot.
| —— | Weight of Guns. | Com- para- tive Weight. | ||||
|---|---|---|---|---|---|---|
| cwts. | ||||||
| 12 | -inch Gun | 90 | 1 | to | 112 | |
| 10 | do. | 84 | 1 | „ | 82 | |
| 8 | do. | 65 | 1 | „ | 107 | |
| 8 | do. | 60 | 1 | „ | 96 | |
| 8 | do. | 50 | 1 | „ | 82 | |
| 32 | -pounder | 64 | 1 | „ | 224 | |
| Do. | 56 | 1 | „ | 196 | ||
| Do. | 48 | 1 | „ | 168 | ||
| Do. | 40 | 1 | „ | 140 | ||
| Do. | 32 | 1 | „ | 112 | ||
| Do. | 25 | 1 | „ | 84 | ||
| 24 | -pounder | 50 | 1 | „ | 233 | |
| Do. | 48 | 1 | „ | 219 | ||
| Do. | 42 | 1 | „ | 186 | ||
| 18 | -pounder | 42 | 1 | „ | 261 | |
| Do. | 37 | 1⁄2 | 1 | „ | 233 | |
| 12 | -pounder | 34 | 1 | „ | 318 | |
| Do. | 29 | 1 | „ | 270 | ||
| Do. | 21 | 1 | „ | 196 | ||
| 9 | -pounder | 31 | 1 | „ | 285 | |
| Do. | 26 | 1 | „ | 323 | ||
| Do. | 17 | 1 | „ | 211 | ||
| 6 | -pounder | 23 | 1 | „ | 429 | |
| Do. | 17 | 1 | „ | 327 | ||
| 68 | -pound Carronades | 30 | 1 | „ | 59 | |
| 42 | do. | 22 | 1⁄4 | 1 | „ | 58 |
| 32 | do. | 17 | 1 | „ | 62 | |
| 32 | do. | 25 | 1 | „ | 96 | |
| 24 | do. | 13 | 1 | „ | 55 | |
| 18 | do. | 10 | 1 | „ | 56 | |
| 12 | do. | 6 | 1 | „ | 56 | |
The recoil, which in all the before-mentioned guns is very great, arises from the blow communicated to the iron in immediate contact with the explosive fluid. The granulatory system of the metal transmits to those grains, or crystals, immediately behind them, the blow or concussion they are subjected to, and these again to others, and so on, until the vibration has passed through the metal, from the interior of the breech to the exterior of the gun.
I am satisfied that in all small guns, from their slight substance, recoil is communicated a great deal quicker than in larger ones; hence arises the well-known fact that in shooting you receive a knock nearly simultaneous with the explosion. The greater and heavier the gun (even carry it up to General Miller’s gun of 84 cwt.) if the proportion which the shot bears to it be not too great, the less will be the velocity of recoil. But in carronades, as will be seen, the proportions are as high as 1 to 55, while in long guns, it is 1 to 429; a very considerable degree of difference.
Our ancestors had but a limited knowledge of the laws of projecting bodies by gunpowder. Their explosive power was not good; for there is clear proof, even since the time of Robins, that the purification of the ingredients has nearly doubled the explosive force. The mechanical construction and outer mould of their guns, were calculated to resist and limit the effects of recoil to a great extent.
Accumulation of metal in the rear of the breech-end of a gun is true science, and of so easy an attainment, that wonder arises in the mind why it has not been effected. The extent to which this principle is worked upon in our gunnery is very trifling; though recoil can by this simple arrangement be nearly destroyed, or so lessened as to add considerable percentage of range to the projectile. Add no considerable weight to the gun, but add it judiciously, behind the end of the chamber and vent, and immediately surrounding the breech. I have tried this to a great extent, on a small scale, “with fowling-piece barrels,” and find that the greatest advantage arises from an additional inch of metal to the extreme end of the barrel, as the recoil is thereby lessened; while, on the contrary, by reducing the exterior end of the breech, until it becomes of less thickness than the sides of the barrel, the recoil is doubled. Guns will some day be constructed as mortars are, with the axles, or trunnions, in rear of the tube and of the vent; for by this arrangement recoil would act less on the mass of metal forming the gun, and more on the base from which it is fired. We are quite aware that an arrangement of this nature could only be applied to certain descriptions of ordnance, and in certain situations; but on forts, or batteries commanding rivers and bays, and even in the bows of steam vessels, they may be placed with great advantage. But this objection may be started: “You could not use guns fitted in this manner horizontally, or nearly so.” Why not? The muzzle could be as easily raised or depressed as the breech, by mechanical means. I should much like to see the principle tried, and I hope to do so.
The following results of experiments prove, that if a true basis is not laid down, all the fabric raised upon it is but one of sand, which will crumble away from under us. Hutton says,—“Varying the weight of the gun, produced no change in the velocity of the ball. The guns were suspended in the same manner as the pendulous blocks, and additional weights were attached to the pieces, so as to restrain the recoil; but although the arcs of the recoil were thus shortened, yet the velocity of the ball was not altered by it. The recoil was then entirely prevented, but the initial velocity of the ball remained the same.” No doubt this was the result of his experiments by the pendulous suspension of the gun: but here he erred; for had he suspended a thousand tons to it, without incorporating it in the gun, the result would still have been the same. All the improvements effected, or yet to be accomplished, will be obtained by a concentration of metal.
An excess of weight in the fore part of a gun is very injurious, by inducing and lengthening the tremulous vibration created by the explosion. The only necessity for strength forward in a cannon, arises from the necessity of resisting the lateral pressure from the condensation of the column of air in the tube. The pressure of the explosive gases is, by the velocity obtained before reaching the fore part, of very little amount, from the short period it is exerted on the interior. Therefore weight, in the fore part of a gun, be it ever so great, will not prevent recoil if there is not a proportionate quantity behind. It will retard or lessen the distance to which the recoil will drive the gun and carriage, but the evil is then over.
If the slightest movement occurs in the gun, the shot is projected from an unsound base or foundation. It is precisely similar to a man who, in the act of throwing a stone, slips his foot backwards: the effect is at once apparent on the stone. If the trunnion of a gun breaks in the discharge, or a quoin flies out, the shot is materially affected; never ranging, under such circumstances, the accustomed distance, nor with its usual accuracy. Practice with mortars proves beyond dispute the necessity of a firm base for the gun, for with a much less charge they project a greater mass farther. A mortar discharged on land, exceeds in range the same description of gun on board of ship, or on the best-constructed platform. In truth, this is but another illustration of a law of nature: if you have not a solid fulcrum, it matters little what the power of your lever may be. Gunpowder is a powerful lever if exploded on a solid base; if not, its effects become limited in proportion. Unquestionably, much may yet be gained by an economical arrangement of our projectile force. Great and rapid as have been the acquisitions of knowledge in everything relating to gunnery in modern times, there still remains, I have no doubt, an unexplored mine of valuable treasure to be added to the science.