Nitre is not the only salt which has been employed in the manufacture of gunpowder. Its quantity or proportion in the mixture has been lessened, and the deficiency supplied by another elementary combination; namely, by the chlorate of potassa.

The French succeeded in making powder of which potassa forms one of the component parts, and they say it ranges the projectile double the distance; but this is doubtful. The proportions of the mixture are nitrate of potash twenty-five parts, chlorate of potassa forty-five, sulphur fifteen, charcoal seven and a half, and lycopodium seven and a half parts. In the year 1809, a similar kind of powder was proposed to the English Government, by a person of the name of Parr; but its introduction was very properly opposed by Sir William Congreve, on account of the danger attending its use, and also from the fact that there was no piece of ordnance in the service able to withstand its effects. The proportions were, chlorate of potassa six parts, fine charcoal one part, sulphur one part. These ingredients to be carefully mixed together and granulated. The above mixture was laid aside, not only from the want of power to restrain its effects, but because it was useless, from the very extreme rapidity of its explosion: it forms the atmospheric air into a wall of adamant, by the condensation confining it to a comparatively small space; it becomes lightning—an electric fluid, which, from its very intensity, cannot displace any great mass of air.

Neither can any advantage arise from any greater velocity in projectile force, except we can obtain that by a graduated scale; for masses cannot, from a state of rest, be put in extreme motion instantaneously: philosophy teaches us, and experience makes it evident, that a portion of time must be occupied, however short that may be. All motion is gradual, and cannot be obtained otherwise; and hence the fact, that lightning conveyed into a tube filled with projectiles would not drive them out: it would not project them, but the blow would break them in pieces. So is it with this mixture; it is useless from its very rapidity of ignition. We have shown that even fine grain gunpowder is too quick, and that its quickness destroys its power; how much more so is the other: and what would it avail us, with these disadvantages.

A writer mentions what he conceives to be a curious fact: he says, “If a train of gunpowder be crossed at right angles by a train of fulminating mercury, laid on a sheet of paper on a table, and the gunpowder lighted by a red hot wire, the flame will run on until it meets the cross train of fulminating mercury, when the inflammation of the latter will be so instantaneous as to cut off the connection with the continuous train of gunpowder, leaving one half of the train unignited:” and again, “If the fulminating powder be lighted first, it will go straight on, and pass through the train of gunpowder so rapidly as not to inflame it at all.” True; and the cause is quite apparent: the rapidity of combustion condenses the air so quickly, as to remove the grains of gunpowder liable to come in contact with the flame, and to form the condensed air into a line of demarcation: for heat cannot be taken up by the air quicker than the atmosphere will convey sound; and before the heat can evaporate the explosion is over, and is consequently noiseless.

In all mining operations: in the quarrying of stone, the destruction of sunken rocks, or in any other operations where it is desirable to detach large masses, the use of gunpowder is indispensable; not only because it decreases manual exertion but also because it can be used under circumstances and in situations unapproachable by other means. It becomes, therefore, a consideration for the miner what kind is best suited for the purpose; the finest grained powder is useless as is well known: it is also more expensive; but its principal defect arises from its quickness of combustion. Masses cannot be detached without first putting the whole in motion; and as this cannot be done in a very short time, it is necessary to prolong the explosion, so that the wave of vibration may have time to travel throughout the whole of the mass acted upon; and a repetition of these waves is necessary before any mass can move. Now, to obtain this, it is necessary that matter be so incorporated with the powder as to prolong that explosion; bituminous substances might be applied with effect, for their slow burning would keep the heat necessary to hold the permanent gases at their utmost stretch of expansion.

It is obvious, from the extremely high character English sporting gunpowder has obtained all over the world, that considerable improvement must have been effected by the private manufacturers, either in the purification or manipulation of ingredients; indeed the unwearied care bestowed on this point by several of our best makers is beyond all praise. To explain the various methods, or otherwise enlarge upon this point, would be injurious to individual skill and enterprise, and be the means of imparting knowledge to those who have not ability to invent, but who gather from the brains of others. The French set great value on the “Poudre de Chasse” of England. It is rather singular that we should excel those who pride themselves so much on their chemical knowledge; but, as before remarked, it is certain that the intimate incorporation of the ingredients is of more importance than the chemical proportions.

All military and naval gunpowder is not manufactured of the greatest strength that can be acquired “at the Government mills;” a sample is furnished to each contractor with each contract, and to this strength he is limited.

The fame of our English gunpowder makers is patent to all the world, and, where skill is equal, to name one rather than another would be invidious; though we must not lose sight of the facts herein established. “Granulation,” properly understood, is an equivalent point to either chemical or mechanical knowledge and manipulation in gunpowder manufacture. Great anxiety to meet the wishes of the sporting world on this point, and to advance with the age, has been aroused; and specimens have been kindly furnished to me, not by one, but by all the following celebrated makers: Messrs. Pigou and Wilks, Curtis and Harvey, Lawrence and Son, John Hall and Son; and I have received also a very excellent specimen from the Scotch mills.

Gunpowder of five sizes of granulation, on the basis before alluded to: namely, No. 2, containing two quantities of No. 1, and No. 3, three, and so on in progression; but it is imperative that all the various sizes be produced from the same mill cake, or be otherwise of the same condensation or specific gravity, and in all experiments of comparison, equal weights are a “sine quâ non,” otherwise the comparison will be futile; as measure is, for these very obvious reasons, inapplicable in comparative tests. When these points are carefully attained, increased power of killing, “decreased recoil,” and much greater safety, will be the important benefits which the gunpowder manufacturers will confer on every one using a gun.

CHAPTER III.
ARTILLERY.

Arcualia, from “arcus, a bow,” appears to have been the original name, and included all sorts of “missiles,” as well as the engines by which they were propelled. The sling, still in common use by the Arabs on the banks of the upper Euphrates, being most probably the first kind of artillery, and the bow and arrow a succeeding stage of improvement.

Artillery, now in the general acceptance of the term, includes all and every description of gun, of greater power and dimensions than muskets and other shoulder guns.

Modern civilization, with its giant strides of improvement, has rejected the cumbrous and unsightly complication of springs, levers and wheels; and given to us, in their stead, the light and handsome six-pounder cannon; which is so easy of transit that it can accomplish the most complex and difficult movements, while the horses are at their fullest gallop. A single minute now suffices to stop when at the greatest speed, unlimber, load, fire a couple of rounds, and remount; the gun is speedily at a distance—while the eye can scarcely follow, or the mind imagine, the destruction that must follow when the “deep-tongued gun” is fired in attack.

I shall now proceed to notice the comparative effects of guns of various calibre and power, and attempt to convey to the reader a distinct idea of their respective defects and advantages. The artillery of England comprises an immense variety of weapons of war, suited for various purposes and situations, as experience has dictated, or necessity required. The present state of our artillery requires an advance to the front, to be in a line with the march of science, as regards the knowledge of gunpowder and projectiles; I may, therefore, be permitted to animadvert on what appears to me to need improvement.

The profession may think it presumptuous in me to offer a suggestion or give an opinion; for it too frequently happens that individuals, who have employed their whole time and study on one especial subject, think they alone can understand it, and consider any opposition to their opinions, or any doubt of the soundness of their conclusions, little short of a positive offence.

Having given considerable attention to the subject, I would now beg to offer some remarks on the Government arrangements of gunnery, which are not yet so perfect as they might be.

The authorities of the Ordnance Department are, I am sorry to state, too remiss in considering, and too unwilling to avail themselves of valuable improvements and discoveries; clinging too much to prejudice in favour of whatever has been heretofore in use. To such an extent is this habit carried, that many improvements become familiar to half the kingdom, aye, and are adopted by other countries, before our guides take advantage of them: for truly talent and ingenuity are but scantily patronized by them. My wish is to aid in sweeping away the cobwebs which still hang on the science of great gunnery; and to push the spur of conviction deep, that instead of Britain following, she may, in a time of peace, lead the way in improvements; so that whenever war returns, she may not be unprepared to wage it on equal terms.

I have in this chapter endeavoured to divest the subject of all extraneous matter, and impart as much information as will enable the reader to form an opinion for himself, and understand something of a science hitherto considered abstract, and which is, no doubt, abstruse. This I have sought to effect in plain language, avoiding, wherever it was possible, all technicalities.

The guns of the British nation may be divided into four classes—Park, or Field artillery, Siege guns, or battering train, garrison guns, and marine artillery. The numbers of different descriptions of rates, or weight of guns, vary in all the different classes of the service. There are light, medium, and heavy six-pounders; long and short twenty-four pounders; and two or more weights in all the varieties, even up to the ten-inch gun and thirteen-inch mortar. We have iron ordnance and brass, for long and short ranges, for small or great velocity. The rate, weight, length, charges, point blank, extreme range, &c., of iron guns, will be found in the annexed table, by which will be seen, at a glance, the various matters referred to.

Iron Ordnance.

Brass guns are invariably lighter, and considered less likely to burst. Gun metal, technically so called, is a compound of copper and tin, in the proportion of five, eight, and ten pounds of the latter to 100 pounds of the former. The peculiar property of the tin is to give hardness and solidity to the mass. The greater proportions are used principally for mortars, as they require a greater degree of hardness than other guns. A peculiar property attaches to the using of brass guns. If a considerable number of rounds be fired in rapid succession, the bore of the gun becomes to a certain extent elliptical. This peculiarity arises entirely from the extreme windage allowed by the present established rules of British gunnery; and is produced by the tendency of the shot, when propelled by the explosive force, to strike upwards from the breech, and then rebound downwards, and so on till it reaches the muzzle. Iron guns are not liable to this (although the same cause exists) from the unductile nature of the cast iron.

Brass guns are, after certain use, recast: this is done solid, with the cascable of the gun downwards, to give a greater density to the metal at the breech. The boring and turning are performed simultaneously by a very simple arrangement. At the siege of Badajos, the firing continued for 104 hours, and the number of rounds that each gun fired averaged 1,249; and at the siege of Sebastian, the quantity fired by each gun was about 350 rounds, in 15¹⁄₂ hours. These guns being of iron, none of them were rendered unserviceable; though three times the number of brass guns would not have been equal to such long and rapid firing. All brass guns are bouched with a bolt of copper at the vent, on the same principle as flint guns for sporting were formerly with gold or platina; copper withstanding the rapid escape of the flame better than the gun-metal. The charges, ranges, &c., are as follows:—

Extreme and Point Blank Range of Brass Ordnance, Charge, &c.

The twelve, ten, and eight-inch guns, almost form a class of themselves, known as the “Paixhan Gun.” They are intended for throwing both hollow and solid shot. The larger are the description of ordnance with which we at present arm our steam frigates.

These are unquestionably part of the many doubtful descriptions of artillery which have been adopted of late years, with a view to fracture more than to secure a range of projectile. They are enormous machines, as will be seen on reference to their weights, as given in the following table; and their splintering powers are certainly very extensive indeed. But their range is contemptibly small, if we take into consideration their great weight. The effect of the explosion of the charge of one of these guns must be sensibly felt even by the strongest built steamer in the world. They are used with traversing beds. The gun carriage, when recoiling, in a backward direction, being driven up an inclined railway, with from 3° to 4° of elevation, from the cascable of the gun. This greatly tends to lessen the distance which the gun would be driven back, and facilitates the running out of the piece to the point of discharge. The woodcut gives a representation of the traversing beds; and the following table displays the ranges, &c., of this class of heavy artillery.

Mortars are intended for three purposes; firstly, to bombard a town, or injure the defenders’ artillery; secondly, to fire or overthrow the works, and to spread havoc and slaughter among the troops; thirdly, to break through the vaulted roofs of barracks and magazines which are not bomb-proof, or, in other terms, are not strong enough to resist the fire.

They consist, as will be seen, of five descriptions, but the 10-inch is considered, on the score of economy, as equal to all useful purposes. The French have, at various times, constructed mortars of enormously large dimensions, but certainly with no useful result. The monster mortar, used at the siege of Antwerp, fired only ten or twelve shots, and with comparatively little effect. It burst some time after, while under a course of experiment, with a considerably less charge than it had formerly withstood; thus affording one very conclusive and illustrative fact in the theory of vibrations in metals: for there can be no question but that the shell, from the smallness of the charge, was too long detained in the mortar; the waves of vibration caused by the explosive force moving so rapidly through the mass that the metal at last lost its cohesive nature from their very rapid succession.

It will be perceived, on reference to the adjoining tables, that ranges are obtained by the modifications of charges.

English Mortar Practice.[3]