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.

---------+-------+-------+------------+------+-------+---------- Nature | | | Charge |Point |Extreme| of |Weight.|Length.| of |Blank |at | Windage Gun. | | | Powder. |Range.|5 deg. |decreased. ---------+-------+-------+------------+------+-------+---------- Pounders.| cwts. |ft. in.|lbs. ozs. |yards.| yards.| 32 | 63 | 9 7 | 10 10-1/2| 380 | 1950 | -- 32 | 56 | 9 6 | 10 10-1/2| 380 | 1950 | -- 32 | 48 | 8 0 | 8 0 | 330 | 1740 | -- 32 | 40 | 7 6 | 6 0 | 340 | 1700 | ·06 32 | 32 | 6 6 | 5 0 | 330 | 1640 | ·11 32 | 25 | 6 0 | 4 0 | 225 | 1500 | ·11 32 | 25 | 5 4 | 4 0 | 225 | 1500 | ·11 24 | 50 | 9 6 | 8 0 | 360 | 1850 | -- 24 | 48 | 9 0 | 8 0 | 360 | 1850 | -- 24 | 40 | 7 6 | 8 0 | 340 | 1800 | -- 24 | 33 | 6 6 | 6 0 | 260 | 1560 | -- 18 | 42 | 9 0 | 6 0 | 360 | 1780 | -- 18 | 38 | 8 0 | 6 0 | 340 | 1730 | -- 12 | 34 | 9 0 | 4 0 | 360 | 1700 | -- 12 | 29 | 7 6 | 4 0 | 340 | 1650 | -- 9 | 26 | 7 6 | 3 0 | 330 | 1600 | -- 6 | 17 | 6 0 | 2 0 | 320 | 1520 | -- Carronades. | | | | | 68 | 36 | 5 4 | 5 10-1/2| 270 | 1420 | -- 42 | 22 | 4 6 | 3 8 | 240 | 1350 | -- 32 | 17 | 4 0 | 2 10-1/2| 235 | 1260 | -- 24 | 13 | 3 9 | 2 0 | 225 | 1150 | -- 18 | 10 | 3 4 | 1 8 | 220 | 1100 | -- 12 | 6 | 2 8 | 1 0 | 205 | 1000 | -- ---------+-------+-------+------------+------+-------+----------

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 15-1/2 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.

-----------------+-------+------+-------+------+---------------------- |Charge.|Point |Extreme|Eleva-| ---- | |Blank | Range.| tion.| ---- | |Range.| | | -----------------+-------+------+-------+------+---------------------- |lb. oz.|yards.| yards.| deg. | Medium 12-pounder| 4 0 | 300 | 1,200 | 3 |} Light 12-pounder | 4 0 | 200 | 1,000 | 3 |} 9-pounder | 3 0 | 300 | 1,200 | 3 |}With round solid Long 6-pounder | 2 0 | 300 | 1,200 | 3 |}Shot. Light 6-pounder | 2 0 | 200 | 1,000 | 3 |} Heavy 3-pounder | 1 0 | 200 | 1,000 | 3 |} 24-pounder | | | | | } howitzer | 2 8 | 250 | 950 | 3-1/2| } 12-pounder | | | | | }With common Shells. howitzer | 1 4 | 200 | 950 | 3-3/4| }When Shot is fired, Heavy 5-1/2-inch | | | | | }they increase the howitzer | 2 0 | 250 | 1,750 | 12 | }elevation 1/2 a deg. Light 5-1/2-inch | | | | | } howitzer | 2 0 | 100 | 1,350 | 2 | } -----------------+-------+------+-------+------+----------------------

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.

RANGE AND ELEVATION, &C., OF 12, 10, AND 8-INCH GUNS, AT POINT BLANK AND EXTREME, AND 10 AND 8-INCH HOWITZERS.

-------------------+---------+--------+---------+------+-------+------ | | | Charge |Point |Extreme|Eleva- Nature of Ordnance.| Length. | Weight.| Powder. |Blank | Range.|tion. | | | |Range.| | -------------------+---------+--------+---------+------+-------+------ |ft. in. |cwt. qr.|lbs. ozs.|yards.|yards. |deg. 12-inch gun, with }| | | | | | hollow shot, }| 8 4 | 90 3 | 12 0 | 240 | 1,550 | 6 weight 112 lbs. }| | | | | | 10-inch, with } | | | | | | ditto, weight 86 } | 7 6 | 57 3 | 7 0 | 210 | 1,500 | 6 lbs. } | | | | | | Ditto | 8 4 | 62 1 | 8 0 | 250 | 1,400 | 5 Ditto | 9 4 | 84 0 | 12 0 | 325 | 1,700 | 5 8-inch gun, with }| | | | | | hollow shot, 48 }| 6 8-1/2| 50 0 | 7 0 | 210 | 1,300 | 5 lbs. }| | | | | | 8-inch ditto, } | | | | | | solid shot, 68 } | 8 6 | 60 0 | 9 7 | 340 | 1,500 | 5 lbs. } | | | | | | Ditto | 9 0 | 65 0 | 10 0 | 300 | 3,250 |15 Ditto, hollow shot | 9 0 | 65 0 | 12 0 | 370 | 2,920 |15 10-inch iron | | | | | | howitzers | 5 0 | 40 0 | 7 0 |2 deg.| 2,078 |12 | | | | 600 | | 8-inch ditto | 4 0 | 21 0 | 4 0 |3 deg.| 1,725 |12 | | | | 730 | | -------------------+---------+--------+---------+------+-------+------

[2] Length of time occupied in flight, 14 seconds, and 15-1/4 seconds.

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]

[3] Artillerist’s Manual.

--------------------------------++--------------------------------+ 13-INCH IRON. || 10-INCH IRON. | Weight, 16 cwts. || 16 cwts. 2 qrs. | Shell filled, 200 lbs.[4] || 92 lbs. | Bursting powder, 6 lbs. 2 ozs. || 2 lbs. 10 ozs. | Blowing powder, 2 ozs. || 1-1/2 ozs. | -------+-----------+-----+------++-------+-----------+-----+------+ Ele- | Charge. |Fuse.|Range.|| Ele- | Charge. |Fuse.|Range.| vation.| | | ||vation.| | | | -------+-----------+-----+------+--------+-----------+-----+------+ deg. |lbs. ozs. |inch.|yards.|| deg. |lbs. ozs. |inch.|yards.| 45 | 2 1-1/2| 1·90| 450|| 45 | 1 0-1/2| 1·90| 450| | 2 3 | 2·00| 500|| | 1 2 | 2·00| 500| | 2 4-3/4| 2·10| 550|| | 1 3-1/4| 2·10| 550| | 2 6 | 2·20| 600|| | 1 4-3/4| 2·20| 600| | 2 7-3/4| 2·30| 650|| | 1 6 | 2·30| 650| | 2 9-1/2| 2·40| 700|| | 1 7-1/2| 2·40| 700| | 2 11-3/4| 2·45| 750|| | 1 9 | 2·45| 750| | 2 14 | 2·50| 800|| | 1 10 | 2·50| 800| | 3 0-1/2| 2·55| 850|| | 1 11 | 2·55| 850| | 3 3 | 2·60| 900|| | 1 12 | 2·60| 900| | 3 5-1/2| 2·65| 950|| | 1 13 | 2·65| 950| | 3 8 | 2·70| 1,000|| | 1 14 | 2·70| 1,000| | 3 10 | 2·75| 1,050|| | 1 15-1/4| 2·75| 1,050| | 3 12 | 2·80| 1,100|| | 2 0-1/2| 2·80| 1,100| | 3 14 | 2·85| 1,150|| | 2 1-3/4| 2·85| 1,150| | 4 0 | 2·90| 1,200|| | 2 3 | 2·90| 1,200| -------+-----------+-----+------++-------+-----------+-----+------+

+------------------------------------+ | 8-INCH IRON. | | 8 cwts. 1 qr. | | 46 lbs. | | 1 lb. 14 ozs. | | 1 oz. | +----------+------------+-----+------+ |Elevation.| Charge. |Fuse.|Range.| +----------+------------+-----+------+ | deg. |lbs. ozs. |inch.|yards.| | 15 | 0 14 | 0·80| 500| | | 1 0 | 1·00| 550| | | 1 2 | 1·10| 600| | 45 | 0 9-1/2| 1·90| 450| | | 0 10-3/4| 2·00| 500| | | 0 12-1/2| 2·10| 550| | | 0 13-3/4| 2·20| 600| | | 0 14-1/2| 2·30| 650| | | 0 15-1/2| 2·40| 700| | | 1 0 | 2·45| 750| | | 1 0-1/2| 2·50| 800| | | 1 1-1/4| 2·55| 850| | | 1 2 | 2·60| 900| | | 1 2-3/4| 2·65| 950| | | 1 3-1/2| 2·70| 1,000| | | 1 4 | 2·75| 1,050| | | 1 4-3/4| 2·80| 1,100| | | 1 5-1/4| 2·85| 1,150| | | 1 6 | 2·90| 1,200| +----------+------------+-----+------+

+--------------------------------++-------------------------------- | 5-1/2-INCH BRASS. || 4 2-5th-INCH BRASS. | Weight, 1 cwt. 1 qr. 10 lbs. || 3 qrs. 19 lbs. | Shell filled, 16 lbs.[5] || 8 lbs. | Bursting powder, 10 ozs. || 5 ozs. | Blowing powder, 1/2 oz. || 1/2 oz. +----------+--------+-----+------++----------+--------+-----+------ |Elevation.|Charge. |Fuse.|Range.||Elevation.| Charge.|Fuse.|Range. +----------+--------+-----+------++----------+--------+-----+------ | deg. |ozs. dr.|inch.|yards.|| deg. |ozs. dr.|inch.|yards. | 15 | 6 0 | 0·73| 350 || 15 | 4 8 | 0·80| 450 | | 7 0 | 0·75| 400 || | 4 12 | 0·85| 500 | | 7 8 | 0·80| 450 || 25 | 4 0 | 1·10| 540 | | 8 0 | 0·85| 500 || | | | | 25 | 5 8 | 1·10| 480 || | | | | 45 | 4 8 | | 300 || 45 | 2 6 | 1·65| 300 | | 4 12 | | 350 || | 2 9 | 1·70| 350 | | 5 0 | 1·75| 400 || | 2 12 | 1·75| 400 | | 5 4 | 1·80| 450 || | 3 0 | 1·80| 450 | | 5 8 | 1·85| 500 || | 3 4 | 1·85| 500 | | 5 12 | 1·90| 550 || | 3 8 | 1·90| 550 | | 6 0 | 1·95| 600 || | 3 12 | 1·95| 600 +----------+--------+-----+------++----------+--------+-----+------

[4] Shells filled with sand, which will account for the weight.

[5] Shells filled with sand, which will account for the weight.

13-INCH LAND SERVICE. 10-INCH DITTO. 8-INCH DITTO. Greatest charge, 8 pounds powder. 4-1/2 pounds. 1 pound. Greatest range, 2,706 yards. 2,536 yards. 1,720 yards.

WEIGHT OF LAND AND SEA SERVICE MORTAR.

Inches. cwts. qrs. lbs. Inches. 13 Land service, Weight, 36 2 0 Length, 36·563 10 do. „ 16 2 0 „ 28·125 8 do. „ 8 2 14 „ 22·500 5-1/2 do. brass, „ 1 1 15 „ 15·104 4-2/3 do. do. „ 0 3 20 „ 12·713 13 Sea service, „ 100 1 14 „ 52·810 10 do. „ 52 0 0 „ 45·620

Carronades are a short description of ordnance without trunnions, but fastened by a loop under the reinforce. Their construction is materially different from that of guns. They have a chamber like a mortar, a part scooped out inside the muzzle, forming a cup, and they have also a patch on the reinforce. The name arises from the Carron Foundry in Scotland, the first of them having been cast there in 1779. The construction is considerably lighter than that of guns of similar calibre. Their principal use is on board ship; but they are sometimes used in casemates, or retired flanks of fortresses.

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 |Comparative ---- | of | Weight. | Guns. | -------------------+-------+----------- | 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.

It would effect a great improvement in the mortars used by the navy, destroying the tremendous vibration and shake given to the ship, increasing their efficiency and aiding the projecting power, to place them on beds of the softest lead, not less than twelve inches in thickness. Though this suggestion is only theoretical, experience would soon determine the least degree of substance available. Advantage would arise, in the first place, from the non-conducting tendency of the lead; in the second, from its density, and, of course, incompressibility. The one protecting the ship, the other being the most solid bed for the mortar that can by possibility be obtained.

The weight of a hollow 13-inch shell is 190 lbs.; the bursting powder 6 lbs. 8 oz.; the weight, if cast solid, would be 290 lbs.: thus the action of so large a body on the atmosphere must be immense of itself. There seems to be much difficulty in projecting masses of great diameter, from this cause; and this should lead us to seek, as indeed it points to, another material for fabricating projectiles. As weight is less in substance, and, of course, less in space, much less resistance, in proportion, will exist in a bore of six inches than in one of twelve; and a greater projectile force will be generated with fewer countervailing disadvantages.

The first step in the vast improvements about to be effected in gunnery, has been successfully taken by Mr. Monk, of Woolwich arsenal, who has induced the authorities to allow a gun to be made from drawings and calculations of his own. The dimensions of the gun are as follows: length from cascable to muzzle, 11 feet; weight, 97 cwt. 3 qrs.; bore, 7-7/10 inches; weight of solid shot, 55 lbs.; shell, 42 lbs.; windage, 0·175; charge, 16 lbs. of powder; giving a range, at 32° of elevation, of 5,327 yards. _A compound shot_, (a shell filled with lead), was projected 5,720 yards, or _three miles and a quarter_, at a velocity, during the first second of time, of 2,400 feet per second, and occupying during the whole flight only 29-1/2 seconds. The comparative weight of gun and shot is 1 to 220.

A course of experiments, extending over seventeen years, has firmly established this gun as the best ever yet constructed. Many attempts have been made to excel it, but all have failed. Guns have been made on drawings varying not more than three-tenths of an inch in their dimensions from those of his gun, and, with extreme _modesty_, the individuals have claimed a right to compete with Mr. Monk; and have even obtained competing trials, without any claim whatever to the discovery of the principle of it; coming into competition by no just claim or merit, but solely from the tendency to supersede any improvement emanating from a _civilian_. Eighteen, twenty-four, and thirty-two pounders are now, however, constructed on this model;--indeed the improvement is so great and so apparent, as to overcome every obstacle as yet thrown in its way.

With no wish to detract from the merit of Mr. Monk’s invention (upon which I congratulate him and the country) but, in justice to myself, I may remind some of my readers, that in “The Gun,” published early in 1835, I clearly laid down the principle in _projectile force_, on which this gun is constructed; and as he has since so successfully accomplished this great improvement, he must permit me to say, that the principle is the same which I have striven for, for many years.

Wilkinson says, “Guns cast on this principle, although several hundredweight lighter altogether, recoil less than those on the old plan, with equal charges of powder and ball, in consequence of the weight being _properly_ distributed.” He adds, “One remarkable fact attended these experiments, namely, that by increasing the windage a little, the range was increased also, contrary to the received opinion; but this may be explained by the circumstance, that with very great velocities, and long guns, the column of air to be displaced before the ball quits the gun is considerable, and is condensed so rapidly, that it offers immense resistance to the passage of the bullet, if it fit the bore closely; but, by reducing the size of the ball, and thus increasing the windage, the air has more space to rush round it, and the ball escapes with greater facility.”

If the condensed air prevented the velocity being greater, it argues most clearly, that there was an insufficiency of explosive matter to keep up the velocity until the ball of less windage left the muzzle; and the result with the ball of greater windage establishes this assumption. For if the condensed air was allowed to pass the ball by the windage into the tube, it proves beyond doubt that there was a deficiency of matter there, or that the pressure without was greater than that within. How otherwise could such a result occur? It is a clearly established fact, that with the generality of ordnance, a full waste of one-fourth of explosive force, if not more, occurs by the _elastic fluid_ escaping past the ball by the windage, instead of the reverse. Neither could the condensed air rush into the gun by the windage if there are any _permanent gases_ generated; which Mr. Wilkinson himself says there are, to the extent of “250 times the bulk of the powder in grain.” These would offer a sufficient resistance to prevent the condensed air rushing in. I have found, by an experiment before described, that a ball driven against a column of air which has no escape, if the velocity be trifling, say 800 feet per second, the air will escape by the windage; but double this even, and it is so condensed as to form a cushion for the ball to strike against. Then how much less will the chance be of its escaping, if the velocity become two thousand four hundred feet per second. No, the cause is remote from that of Mr. Wilkinson’s supposition. There is a want of force--an accelerative propellant force--which should continue to the end of the tube, be that length ever so great; and on this point, for one, turns the whole future improvement of gunnery.

The result wished for can be obtained by a systematical arrangement of the granulation of powder. That a much greater velocity than is obtained in this gun--at present the greatest in any piece of ordnance in use, and possessing a longer range than has been obtained by any power in Europe--may and will be attained, I fearlessly assert. I have obtained a velocity with an ounce ball nearly doubling this; and though, as it will be argued, this may be too limited an experiment, yet let us not forget that great results most frequently spring from little causes. Large rivers owe their origin to small springs, and if the same principle by which we can penetrate a plate of iron half an inch thick with an ounce of lead, be fearlessly and judiciously carried through, we may (and no doubt we shall) live to see projectiles thrown 5-1/4 miles. That this will be difficult to accomplish I deny: no difficulty attends it, provided the principles before explained are duly carried out.

The great principle in a propellant force is so to arrange it that you do not obtain too great a velocity at the first move of the projectile; as no mass can be forced from a state of rest to a rapid state of motion, without communicating to the gun a corresponding motion, which will create a recoil: and the greater the motion, the greater the recoil. If the explosive matter merely expands for a brief period, and is burnt out before the shot has reached midway the length of the gun, the velocity there acquired will be reduced, by the condensed column of air in the other half of the barrel, to the velocity it possessed when only one fourth the length of the whole from the breech; consequently it would be advantageous to cut the gun in two at the middle, as a greater force would be then generated advantageously, than by the whole. But if you so arrange the granulation of your powder that it shall proceed into motion more gradually, a rapidly increasing force of elastic fluid will continue to be generated, until it reaches its greatest maximum of velocity (which it should do just as the ball leaves the muzzle) then you obtain with your means the greatest result possible.

We believe that the generality of gunpowder used by our Government is vastly inferior in strength to some made by private makers; yet it is not advisable to jump from one extreme to another. What is wanted is the proper blending of the qualities; an addition of a quantity of Harvey’s quick powder to a charge, when it has driven the ball up three-fourths of the tube of a gun, and probably had acquired a velocity of 2,000 feet per second, might so aid it, that it would leave the muzzle with a velocity of 3,000.

You cannot put a locomotive train in motion at once: if it were attempted, you would break all the carriages; but if you gradually add your force, you gain in time the greatest possible velocity. I have drawn a parallel case: it is the same with gunpowder; only the velocities are widely different. Therefore, I may be pardoned, if I say gunnery is like steam, but in its infancy. Let us but clearly see and understand aright the principle--knowing that the greater momentum the less the action of the atmosphere--and if 3-1/4 miles can be obtained with a ball 60 lbs. weight, 5-1/4 may be easily accomplished by a ball of 120 lbs. Powder is made, and can be had, that will do this.

The use of compound-shot has of late years become quite common in experiments: why lead, with its alloys, has not been more extensively used as a projectile for large guns, has always appeared to me extraordinary. Its weight and density peculiarly fit it for this purpose, and its non-conducting principle is its greatest recommendation. How is it? In no instance, except as compound-shot, do we find any record of the use of leaden bullets on a large scale, save in Sir Howard Douglas’s “Naval Gunnery,” where, in a note, he says, “A very distinguished naval commander mentioned to me, that he knew a person who had served in an American privateer, which, being out of shot, and unable to procure a supply of iron balls, used leaden shot as substitutes. This person always mentioned with great surprise the superior effect of leaden balls.” Well he might; for the reader need not be told that its greater specific gravity would add to its momentum, and a longer medium velocity be retained during its flight. But it possesses another recommendation, superior to all these, in warfare: that of communicating all its force, all its velocity, be they ever so great, to the body struck. Iron does not possess this quality; except to a certain extent, and that at low velocities. Hence the cause of its being found in naval warfare, that balls at low velocities damage and destroy ships’ sides more than at higher velocities, even when passing quite through. Lead, in the act of striking hard substances, iron or stone for instance, is partially flattened, until the flat surface is nearly equal to the diameter of the sphere of the ball; thus parting with all the force it struck the object with, and in most instances falling motionless at the base of the object struck; while in the stone, the surrounding crystals or grains are, by their abrasion on each other, pounded into dust, in proportion to the size and force of the body of lead striking them: in many instances to many times the shot’s bulk, and only flattening the lead, less or more, in proportion to the capability of the stone to resist. Iron striking stone retains its shape: the grains are driven back upon each other, and each offering its proportion of elasticity, the ball is enabled to rebound back; which it does in many instances to a considerable percentage of the whole distance it had been projected. The greater the velocity with which an iron ball is projected the greater the rebound back from a hard substance such as stone. Reversely, the greater the velocity of lead, the greater its effect on the object struck. Walls or fortifications struck by leaden balls at the same velocities (waiving the advantage to lead by its greater specific gravity) would be pounded into sand by less than two-thirds the same number of lead as of iron shot. Any unprejudiced person may soon satisfy himself of this, by trying it with a musket or fowling piece. A leaden ball will pound itself a hole many times its own bulk, while an iron ball will not make a hole half its size.

I have tried many experiments to ascertain the penetrating powers of iron and lead relatively, by striking various objects, from a boiler plate of half an inch thickness down to fir deals. The same size of lead will, under certain circumstances, punch a perfect hole in a plate of half-inch thickness, as I shall have occasion to show; while, under precisely the same arrangement, the iron ball would rebound back with very little diminution of force; and if the plate of iron be at a perfect right angle, the iron ball would nearly return into the muzzle, of the gun. In truth, I had a narrow escape seventeen years ago, from a bullet actually cutting the rim of my hat: so that it will be well, when experimenting in this way, to be sure that the person is well esconced, for fear of unpleasant results.

Lead, therefore, for destroying ships, as well as stone walls, is unquestionably highly advantageous; even if projected with the same velocities as at present adopted for iron. The additional weight would not decrease the destructive effects; it would augment them. I perfectly agree with the American _privateer_, that the wonderfully destructive power of leaden cannon balls will create surprise, whenever they shall come generally into use. Imagine the effect from a gun of the dimensions of a 10-inch bore. It is dreadful to contemplate.

The effect of lead will be easily understood when explained in the following way. If a 36 lb. shot have a velocity of 2,000 feet per second, the force is equal to the velocity multiplied by the weight, or 72,000 lbs. The whole of this force would strike a wall, and be left there, if communicated by soft lead; if by iron, at the same velocity, it would be minus the amount of force required to make it rebound to the great distance to which iron invariably returns. Though created by the elasticity of the iron itself, this must be deducted from the effect produced, and hence arises the great advantage the lead possesses. We are aware that iron driven with a slight velocity rebounds less; true, and less is its real effect; for under the very same circumstances would the great advantages of the lead predominate. It may be objected, that lead is too easily misshaped; “pure it is, but with alloys not so.” At low velocities it might, but the greater velocities diminish that chance, as it is a well known fact that all dense incompressible bodies are least affected by an extremely sharp motion. All our arrangements in warlike preparations, at present, involve great weight of projectile for fracturing, not perforating. During the siege of Ciudad Rodrigo, 2,159 rounds, of twenty-four and eighteen pounders, were requisite to form the small breach of thirty feet wide, and 6,478 rounds for the larger of 100 feet. At Badajos there was expended, to form three breaches of 40, 90, and 150 feet respectively, the enormous amount of 31,861 rounds of the same sized iron shot. We may be pardoned if we presume to say, one-half the number of lead shot would have done more, and done it better.

If we bear in mind, that the whole round of experiments from which Hutton drew his deductions, were conducted with iron projectiles, the inconsistency of taking his data as the standard will be apparent. The dissimilitude of specific gravities being great, namely, 7,425 and 11,327--or one-third difference--it clearly shows, without any effort of the imagination, that the range must be in the same proportion, with the addition of greater momentum. For it will scarcely be denied, that a ball of gold or platina, from the same cause, will maintain a velocity longer, and consequently range further, than even lead. Hutton’s theory only establishes the principle, that the lighter the body projected, the sooner it is acted upon by atmospheric resistance, and a medium velocity induced. We cannot attribute his preferring iron to arise from an opinion of its penetrating to greater depths; for a man of his extensive knowledge and research could scarcely be guilty of such an error. But even in our enlightened times we are told that elephants cannot be killed with any projectile but steel: leaden balls cannot do it. I should like to try, and receive the _tusks_ in return.

The shrapnell shell (invented by General Shrapnell), or spherical case shot, introduced into the British service of late years, is probably the most destructive of any missile in use. It was intended to supersede--which it has done--canister and grape shot; effecting the same results at treble the range. The construction and principle are very simple, being merely a shell of an unusually light description; in fact, little more than a light cast-iron hollow ball, with a fuse hole. A certain quantity of leaden, or iron bullets is put into it, and the interstices around the ball shaken full of powder; a fuse of the length required is inserted, and explodes the shell during its flight: the peculiarity being, that the body of small balls retain their medium velocity and travel on, merely diverging, latterly, like an immense charge of bird shot. They are usually fired from howitzers, carronades, and other wide bored-guns, at or near horizontal ranges. A considerable delay occurred before they were successfully perfected. It was found that when the small balls did not pack perfectly tight, or were packed overtight, the case frequently exploded in the gun: occasioned, no doubt, by the friction creating a spark at the moment of the howitzer being fired, and thus exploding the shell before its time; but we believe such an occurrence rarely happens now, from other improvements since adopted.

The preceding pages appeared in my last work published in 1846. They are still so much in keeping with the state of gunnery at the present day, and so prophetic of what has, and is about to occur, that they will be regarded, I trust, as bearing the stamp of authority.

Progress, in its rapid advance, has made many English guns objects for the furnace or the museum; and many guns, which formerly ranked high as useful and important weapons, have become things of the past.

Monsters are now all the rage, with a range of three miles, and artillerists contemplate extending the range to double that distance; whilst the projectiles used are not “pounders,” but approximating to tons. So much for improvement. In political economy we are told that improvement to be good must be gradual; but only effect some slight improvement in gunnery, make but one step in advance, and the desire for further improvement then ranges at will, and impossibilities are craved for and sought to be attained.

Twelve years ago the success of Mr. Monck (certainly the first modern improver of ordnance,) led to the unlimited production of undigested plans for changes in gunnery; but, unfortunately for the science, no progress was made on the one great improvement of Mr. Monck.

War found us ill prepared in the field, and out-weighted “afloat,” so that almost as many men were killed by the bursting of mortars, and other ill-constructed guns, as by the fire of the enemy: so critical was our situation, indeed, that but for the general adoption in England’s army of my great invention, the rifle on the expansive or “Greenerian” principle, and its skilful use by our brave soldiers, the war had gone against us. Our rifles were equal in range to our artillery, and this saved us; whilst the enemy, astonished at the effects produced by our bullets, and conscious of their inferiority both in the construction and use of small arms, abandoned the contest: but no doubt with a firm determination to profit by their dear-bought experience.

It is generally admitted that our artillery was never so effective as that of the enemy, and that more is due to the patient and enduring bravery of the British soldier than to our field-pieces and heavy ordnance. That England’s artillery was at this time most disgracefully inefficient, it would be folly to deny. The larger guns were destroyed in an inconceivably short space of time. After five, ten, or fifteen rounds were fired the guns burst, killing the gunners in great numbers.

The readers of my works are already familiar with my opinions on this subject, and their value will now be enhanced by the fact that they have been proved to be the opinions of a “practical man.” Success in the improvement of small arms is a sure encouragement to those anxious for the advancement of projectile science, and it is a coat of mail in which to fight against the prejudices and incompetency of official management.

Who, on reading my work of 1841, believed the prediction I therein made, that small arms would be produced which would render field guns useless? The fact is, however, firmly established, that the best rifles on my principle will out-range by several hundred yards the best “six-pounder” in her Majesty’s service; and that, too, with a repetition of fire wonderfully quick and effective: as the Russians in the Crimea can testify, on more than one occasion.

To endeavour to point out that an improvement may be effected in artillery equal to that which has been effected in small arms, is the object of the following pages.

The author asks a dispassionate perusal and careful study of his work, in justice to himself and to the importance of the subject. Judging of future probabilities by what has already been accomplished, the reader will be prepared for what follows. That great and important changes must take place in artillery cannot be doubted, and should England refuse to avail herself of the improvements to be effected, other nations, and amongst them our late opponent, will be the first to seize and adopt them. In former works I have asked the indulgence of my military readers on account of my scanty military knowledge; but professional men appear to be equally in the dark with the uninitiated: indeed, the lamentable shortcomings of the English artillerists have placed them in the rank of mere “waiters upon providence” for the next step towards improvement. The present time is decidedly propitious; let improvements now be made, and we may surely hope that they will be appreciated by the public, if not by the Government authorities.

What is the best metal for cannon? is a question which has often been asked, and the answers have been very conflicting. Some have advocated mixtures of copper and tin; others have advocated cast iron, and more recently wrought iron; still more recently steel, and, lastly, cast steel, have had their advocates. Arguments as plentiful as summer flowers have been advanced in favour of each, and the argument has been carried on with a vast amount of prejudice and warmth, according to the degree of acquaintance with or attachment to the favourite metal of each individual. It is rare to meet with a mind free from bias, equally well acquainted with the merits of the several metals, and their application to the purposes intended. Still more rare is it to meet with a mind possessing all this metallurgic knowledge, and combining with it an intimate acquaintance with the principles of projectiles, as well as a scientific knowledge of the construction of the engine (the perfection of which consists in its having no points which are weak or unnecessarily strong); and yet it is by such a combination of knowledge and the application of these principles that we must be guided, if we would be successful in the accumulation of projectile power. In the present age we are really alive to the advantage of “playing at long bowls;” and the question now to be determined is, what is the greatest weight of shot and shell we can throw, and how many miles can we project it. The Americans were undoubtedly the first to discover the great advantage of this question with their lesser frigates; the late war has developed it still more; and it now remains to be ascertained how much further can we go. For on this important point the superior efficacy of artillery depends.

At St. Sebastian, in 1813, cast-iron guns threw tons of shot at a range of 1,500 yards; some particular guns firing as many as 3,000 rounds, and yet it is more than probable that had the same guns been used in the Crimea, they would have burst with one-fourth the number of rounds. Experience proves that it is not the great number of rounds fired which strains and destroys the gun, but the high elevation at which these guns are placed, in order to get range; this it is which shakes and disintegrates the crystalline structure of the metal, and thus extreme range is obtained at extreme cost. A gun which at 6° of elevation could stand without a strain 200 rounds, would be likely at an elevation of 30° to burst before 50 rounds were fired. The explanation of this is sufficiently simple. A gun fired at 6° recoils as the projectile is projected forward, in proportion to its relative weight and friction; but when brought up to an elevation above 30° the gun is entirely out of the horizontal, and cannot recoil as it does at an elevation of 6°: the force is now exerted downward, and the gun impinges on its support--_i. e._, either upon its bed on the deck of the ship, or on the solid earth of the battery, which is comparatively immovable; thus the force which displaced the gun in the first instance is now exerted on the sides of the gun, and the projectile receiving additional force is projected further. But this increased range is obtained at the expense of the gun, which is rapidly destroyed: 50 rounds being sufficient to render it unfit for service. To obviate this rapid destruction of cannon, the metal has been changed from the molecular to the fibrous; that is from cast iron to wrought iron. One object of this chapter is to point out the difficulties which arise in determining what the best metal for cannon really is, and to show the advantages to be gained by attending to the proper construction of projectile engines, without attaching undue importance to the _material_ of which they are made.

Before rejecting cast iron as useless for the construction of large guns, it would be well to assure ourselves that no better quality of metal can be produced than that which is at present manufactured. We must also satisfy ourselves that we have clearly understood the proper shape and form of cannon to resist concussions. These concussions, be it remembered, were more violent in the late than in any previous war; and it is an undoubted fact that we had many more fractures then than on any previous occasion: first, on account of the strain produced by the great elevation required to get increased range; and, secondly, on account of the imperfect shape of the gun. The average number of rounds fired from the 13-inch mortars which burst at the bombardment of Sweaborg was 120, and the fracture in all was peculiarly alike; being at right angles to the supports. Now, that this is due to the form of the gun cannot be doubted; and it will be shown more fully in a subsequent page.

But there is another cause to which I wish now to direct attention, viz., the jamming of the Lancaster shell, which takes place in the increasing spiral of the oval gun at the very point where the projectile acquires a proportional increase of velocity. The effect of this may be illustrated by running a locomotive at its maximum of speed over an increasing curve in the railroad, with the certainty of landing it in an adjoining ditch. The principle which determines the result is quite immutable: viz., that matter in rapid motion cannot be materially affected by any force inferior to the primary force: the tendency of the body being to go straight forward; whereas a slow train goes round a curve with the greatest ease. Two motions can easily be given to matter in a lower velocity; but not so easily when the velocity is much increased. Hence I fear that the inventor of the Lancaster gun must have had a misconception of the true laws of motion; for by increasing the degree of spiral at the muzzle, instead of at the breech of the gun, he has rendered nearly useless what would otherwise have proved a most formidable engine of war.

From these observations it may, I think, fairly be doubted whether the bursting of cannon is owing entirely to the inferior quality of the cast iron used in their formation; though there can, I think, be no doubt that English cast iron is not only much inferior to what it formerly was, but that it is also inferior to that which is now manufactured in Russia. Why it is so will be subsequently explained.

These defects in cast iron have naturally led to many attempts to substitute for it a more durable metal; and in most cases the metal selected has been wrought iron. Wrought iron has been used, not only in solid cannon, but in the original “hoop and stave:” “staves outside,” and “staves inside,” as in Mr. Mallet’s monster mortar. Forms of gun as numerous as can be conceived have been constructed, only to prove themselves in every case most complete failures. Our friends at the Mersey Works, Liverpool, will, no doubt, demur to this assertion; as “all creations of the mind appear most perfect to the father of the thought.”

Great credit is, however, due to the enterprise and energy displayed by the inventors, forgers, and finishers of this great gun; which has been the wonder of many minds in this age of wonders: and it is a highly important invention, as showing what we, as a people, are capable of producing by our mechanical and engineering skill. But here, in my estimation, the wonder ceases; for so sure as there is any truth in the Scotch proverb, “A silk purse cannot be made out of a sow’s lug,” so surely is it true that no man, however great his genius and working powers, can make a good cannon of wrought iron. When the hardness and ductility of silver can be imparted to and held by lead, then will it be possible to make wrought iron accomplish all the purposes required of a good cannon.

In vain may Mr. Horsfall urge that his gun has never been burst. Why? Simply because it has not yet been subjected to the same amount of pressure on the square inch; neither has it been tested at the same elevation as some other 10-inch guns, which, in proportion to their size have stood a more severe test. It is a fact, which may be clearly demonstrated, that if a 10-inch gun of 95 cwt. be fired at an elevation of 40° with 17 lbs. of gunpowder, then a gun of more than six times that weight would not be overloaded if its due proportion of powder were about 100 lbs. Has this gun been fired with one half of this? Until it has been satisfactorily proved to this extent, we feel sure that the authorities are justified in not considering Mr. Horsfall’s a successful achievement.

Whatever may be Mr. Horsfall’s impression with regard to the advantages of wrought iron for making cannon, I am satisfied, after a long and careful study of the results of all its varieties, from the most ordinary to the most perfect combination that has been manufactured--either for tenacity, tenuity, or resistance of lateral pressures--that it cannot answer in large guns.

This I think any one will admit, after considering the two following facts; which apply equally to all varieties and mixtures of wrought iron.

1. The strength of iron is at its maximum in the smallest mechanical structures.

2. The quality of the metal is improved as it is subjected to greater pressure and condensation.

The extent to which this improvement may be carried has never yet been ascertained; every fresh manipulation improves its quality. The tenacity of wrought iron is best displayed in a wire, drawn out until it is not thicker than a human hair. Large masses of wrought iron are weak and spongy in geometrical progression with the mass, and the crystalline or molecular form increases with the mass. If large forgings are carefully examined, crystals will be found whose facets would produce inches of surface; as was clearly demonstrated by the bursting of a 10-inch gun at Woolwich: made, if we mistake not, by Mr. Nasmyth.

Another very important cause which renders large masses of wrought iron unsound (and which was fatal in Mr. Nasmyth’s gun) is the impossibility of condensing tons of wrought iron equally all through the mass. No one has yet been able to overcome this difficulty.

When the force of a blow, however great, is exerted on the surface of a mass of metal, its effect is neutralized within a few inches of the surface; condensation takes place in inverse ratio from the point of impact, and thus the effect is limited. The force which produces this condensation tends also to elongate the fibres of the metal. This elongation is greatest in the immediate vicinity of the force; the fibres in the interior of the mass are less elongated therefore than on the exterior; and the fibres in the interior of the mass being less ductile (from the cause already explained) than those on the exterior, the interior of the mass elongates, by disintegration of its fibres or crystals, and a porous open mass is thus produced, surrounded by a fibrous case. Instances of this are to be seen in broken engine-shafts and anchors; and, indeed, in all large masses of wrought iron, whether fractured by design or accident.

Another cause of this defect in large masses of wrought iron, is the long continued heat to which it is necessary to expose such large forgings. The iron expands as it is heated, but it does not expand equally all through the mass; and the result of this is that the interior becomes porous and spongy: an appearance which must have been observed by every one who has operated upon large masses.

The shaft of the _Leviathan_ weighs 26 tons; but, instead of resisting twenty-six times the pressure of a shaft one ton in weight, it will, from the causes already mentioned, be found unequal to half that amount.

We have watched with much interest the forging of these immense shafts; and the difficulties attending the forging of this structure prove the accuracy of our reasoning on the strength of large masses of wrought iron. The weight of the shaft when finished is 26 tons, and the waste during the process of welding amounts to 74 or 75 tons.

The present shaft is the third which has been manufactured; the two first having proved notorious failures: thus 200 tons of iron have been wasted; which we think is sufficient proof either of the unfitness of the material, or of imperfection in the method of construction. Moreover, I fear that when the vessel encounters a rolling sea, the sudden check and strain produced by the total immersion of one paddle-wheel and the freedom of the other, will subject the present shaft to a strain which will affect its duration; and a vessel costing nearly a million of money may thus be left to reach her port with crippled powers of propulsion.

Where, it may be asked, is the skill in devising engines more powerful than the ingenuity of man can beneficially work out? This has indeed been done in the case of the _Leviathan_; a monster vessel has been built, but all the engineering skill expended upon it has as yet been insufficient to bring it to perfection.

The skill hitherto displayed in welding large forgings of wrought iron into shafts, or other large masses, has been of a very low order; much more may be done than has yet been accomplished, if men will only set about it in a scientific manner. The present mode of proceeding is to build a structure of iron much as a builder would raise a structure of bricks; large and small pieces being mixed together until the requisite mass is obtained.

Now, a much simpler method, and one which we have tried on several occasions, is first to construct several segments of iron of the requisite length, and of dimensions equivalent to the intended object; each segment being fitted to fill its place amongst a given number of other segments (whether twenty, forty, or fifty segments be required,) so as to form a complete cylinder; as the wood-cut will fully explain:--

In welding this structure, the heat is equally diffused all through the mass; and thus the great evil of unequal expansion and contraction is avoided. When the steam hammer is brought into play, its face is a “swage” of circular form, calculated to clasp a large portion of the upper part, whilst a corresponding space is formed in the anvil; and by gradually turning the shaft, the whole is forged into a perfect round. The peculiar advantage gained by this mode of proceeding, is not only the facility with which heat is diffused through the mass, but that each segment is made to act like a wedge on its neighbour; thus producing the most solid forging that has yet been attained. This is rendered still more perfect, both as regards strength and durability, from the fact that a hollow axle has been produced; the great advantages of which it would be out of place to dilate upon in this work.

We trust that these anticipated misfortunes may be avoided by the construction of a more perfect shaft; and that, not only for the sake of the shareholders, but for the credit of the engineer who devised this great vessel--deservedly one of the wonders of the world. A spare shaft would be profitable ballast, if of no more value to the _Leviathan_.

Rolled railway-carriage axles were constructed for me with perfect success on this principle nearly twenty years ago, at the Walker Iron Works, near Newcastle-on-Tyne. The idea has, however, been in a measure “shelved;” but necessity will bring it into use again.

The only engineer who has, by practical experience, satisfied himself that large masses of wrought iron are totally useless for making heavy ordnance is Mr. Nasmyth; whose monster cannon, which was to astonish the whole world, proved, when heated, to have so little cohesion that it would scarcely hold together whilst being lifted from the furnace to the anvil. And, to his credit be it said, Mr. Nasmyth, seeing that wrought iron would not answer the purpose, manfully gave up his hopeless task. Similar experience would probably make some of our present engineers wiser men.

My experience in manufacturing the largest wrought iron guns which it is prudent to construct, sufficiently proves the truth of these assertions.

Harpoon gun-barrels, one inch and a half in the bore, having the metal at the breech end an inch and a quarter thick, will stand a proof which invariably bursts a thicker barrel; in fact, all experience tends to show that light wrought iron or steel barrels are stronger than unusually heavy ones. As all depends on the principle of condensing the fibres of the iron, _ceteris paribus_, the greater the condensation the greater the strength, and the less the condensation the greater the weakness.

That this argument applies principally to solid forged guns I am ready to admit; and that guns forged of hoops, rings, and bars, in smaller sections, are free from this objection, I am also ready to admit. These guns are, however, liable to objections equally fatal, both as regards their enduring and projective powers, as I shall presently show. Experience proves that brass guns are inferior, both in sharpness of shooting and in range, to cast-iron guns: this is undoubtedly attributable to the greater softness of brass than of cast iron; and for the same reason a wrought-iron gun, though made as sound as one of cast iron, would be inferior in these two important points. But when a wrought-iron gun is composed of many particles imperfectly secured (and no mechanical force is sufficient to secure perfect cohesion in large masses), the wrought becomes doubly inferior to the cast gun: a shot projected from such a gun starts from an unsound base; a large portion of the explosive force is absorbed by the variety of sections composing the gun, to the injury both of the accuracy and length of range of the projectile. The softer metals cannot be beneficially used in the construction of large guns, because they destroy the force of the expellant without making any equivalent return; and the softer the metal and the greater its substance, the more clearly is this important fact demonstrated. Thus, in experiments made with large cannon for increasing the weight of the gun beyond a certain proportion to that of the projectile, a gun of ten tons weight and ten inch bore would not exceed in range a gun of five tons, if the charge of powder were the same; on account of the indisputable fact that much more force of the expellant is destroyed, whilst more than double the force is absorbed for the recoil of the ten ton than of the five ton gun; and the loss from these two causes must materially affect the flight of the projectile, though fired at exactly the same elevation.

The great defect which experiment shows to exist in the hoop-and-stave wrought iron gun, and which renders the gun self-destroying, is separation at points between the trunnions and cascable of the gun. The force acting first upon the breech, it yields, and the force is then brought to bear upon the longitudinal portion of the gun behind the trunnions; the staves have thus to bear the first strain, and, after a few shots, become elongated. An opening of the hoops at their junction with each other (most frequently between the breech and trunnions) begins, after a very few shots, to be distinctly visible, and increases at every discharge, until further proceeding amounts to madness, or recklessness of human life.

That enormous engine, Mallet’s monster mortar, of which I give an engraving on page 100, clearly proves this to be the case. It will be observed to be constructed with a solid cast iron breech end, the dimensions of which will be seen by referring to the engraving. Abutting upon this are a succession of wrought iron hoops, ingeniously inserted into each other, and more firmly secured by six outside staves of great dimensions, which, at the muzzle ring, pass through openings in the muzzle ring, with heads like enormous rivets. The binding power is given by “quoin-like” wedges, driven through the opposite end of the stave, beneath the projection of the cast breech, giving power to tighten the longitudinal binders by a blow when required.

DIMENSIONS.

Tons. cwt. qrs. lbs. Cast iron base with wrought iron breech shrunk into bore 21 19 0 2 Wood carriage complete, with wrought iron screw and spanner for elevating mortar 8 8 0 14 Bottom part of mortar to fit on top of the breech 7 5 3 23 Part of mortar (a ring) to fit on the top of the above 5 8 3 23 Do. do. do. 3 0 2 13 Muzzle ring 1 2 3 12 Wood ring 0 0 1 0 Wrought iron ring 0 4 3 4 Wrought iron conical ring to fix on top of muzzle ring 0 3 3 25 T-headed bolts, with gibs and keys for fixing mortar to base: may be called outer staves 1 16 2 0 Wood-wedges, &c., for elevating 0 13 3 22 Outer pin, with cross for turning mortar round 0 8 3 14 ------------------ Total weight 50 13 2 21

Weight of shell unfilled, 26 cwt. 2 qrs.; diameter, 36 inches.

This is notorious as a monster failure, even with a charge of powder amounting to only one half what the projector fondly hoped would be perfectly harmless in its effects. This Brobdignagian toy has proved to be fearfully expensive, the cost having been estimated at eight thousand pounds. It has, I believe, been the largest and most expensive experiment indulged in by the noble “projector,”[6] and I sincerely hope it will be the last.

[6] Lord Palmerston.

The preceding pages will have done much to remove from an unbiassed mind any favourable impression of the advantages expected to result from the use of wrought-iron cannon. The knowledge of this subject, even among talented and scientific men, appears to be at a very low ebb, as is evinced by the multitude of failures that have taken place; not one success of any moment has as yet been attained, and not a discovery has been made worthy of being chronicled.

* * * * *

Having enlarged thus much on the qualities of a metal which it is certain can never supersede the use of cast-iron, even though it be freed from the defects found practically to exist in our present constructed iron artillery; and having also alluded to the fact that the _form_ has much influence on the durability of cast-iron guns, I now proceed to the more important point of the qualities of cast-iron itself.

Little doubt exists that guns cast a hundred years ago were more durable than those of more recent formation; it is evident, therefore, that apart from mere form, some material depreciation must have taken place in the quality of the metal. The use of hot blast-furnaces, better fluxes, and improved chemical knowledge in the reduction of metallic ores, though highly profitable in a commercial point of view, doubling the products of our mines, and enriching their proprietors, has, unfortunately rendered English cast-iron perfectly unfit for the formation of cannon, if increased range and greater strain by high elevation are to be the order of the day.

The durability of Russian cast-iron is unquestionably greater than that manufactured in England. Some cause must exist for this; and the question arises, is the ore superior to ours, or does the superiority of Russian iron depend on their method of smelting? The latter is, we believe, the cause of the superiority of Russian iron; for experiments show that Russian ore, smelted in an English furnace, yields the same kind of cast-iron as is produced from the ore found in England. The inference, therefore, is plain, that the difference in the process of smelting makes all the difference in the quality of the iron.

Two thousand years ago the Romans, or their dependents, smelted iron in the county of Durham: vast accumulations of slag exist there at the present time; and thousands of tons have been beneficially re-smelted by two adjoining iron-works, and a percentage of iron obtained sufficient to prove that the Romans were little indebted to fluxes or hot blasts for the quality of iron they obtained. The Russians cannot boast of these adjuncts any more than the Romans: the old agents, wood and energy, are alone employed in the smelting of their ores; and in the absence of scientific aids, though they obtain a much smaller aggregate quantity of metal, yet it is undoubtedly of a much superior quality. With the Romans, also, the yield was meagre, but the quality was good; now, however, circumstances are reversed, quantity, not quality, being the order of the day.

The use of coals instead of wood in the process of smelting has introduced a mixture which is very prejudicial. Most of the coal, even from our very best mines, contains a large quantity of pyrites, or bisulphuret of iron, which, combining with the cast-iron, injures it to an incalculable extent.

These facts fully explain why our cast-iron guns are not so good now as formerly. Select the most suitable mine in the kingdom, erect a furnace on the most improved principles, employ wood fuel only, avoid fluxes and hot and cold blasts, and be content with the small amount of metal produced, and beyond all doubt the quality will be all that the most sanguine founder or artillerist could wish.

Thus the inferiority of our cast-iron guns has been accounted for, and a method suggested, which, if efficiently carried out, would effect the desired improvement.

* * * * *

We are indebted to Krupp for the first suggestion of, as well as the first attempt to introduce, a cast steel gun of greater durability and power than the best cast-iron gun which has yet been manufactured. Steel, possessing, as it does, hardness to any desired extent, ductility in an equal degree, tenacity unrivalled, and all the other requisites, is destined to take the place of all other metals in the construction of artillery. This metal waits only to be tested; and the greater the extent to which the trial is carried, the more confident we are that it will answer every purpose.

Krupp, like many other men with valuable ideas, has been peculiarly unfortunate in his attempts to carry them out. With a vast amount of knowledge of the science of metallurgy, he wants more knowledge in the not inferior science of projectiles; the most important point being to ascertain the form of gun calculated to be suitable for new metal, of the use of which, for cannon, the world possesses no antecedent knowledge.

The only failures Mr. Krupp has made (if they can, strictly speaking, be so called), have arisen from mal-construction, imperfect form, and unscientific combinations; defects which might be expected from a mere novice, though not from experienced artillerists or founders of artillery. The trial of the only steel gun sent by Mr. Krupp to this country, was conducted in the most absurd manner, and on wholly unscientific principles. I will endeavour to convey some idea of this most extraordinary of experiments. Whether Mr. Krupp was unacquainted with the durability of his metal, or was persuaded, against his will, to conduct the experiment as he did, I know not, but the following is what took place:--

In 1851 Mr. Krupp brought to Woolwich a specimen steel gun of ten-inch bore, weighing about four tons. He was induced (but why, I am at a loss to conceive,) to construct a cast-iron jacket, or outer gun, into which his steel gun was inserted up to the trunnions. The steel gun was separated from its cast-iron jacket by a space of half an inch in its whole length, except at each end, where the jacket was fitted to the gun with a moderate degree of tightness; thus the gun and jacket consisted of two tubes, one within the other, fastened only at their extremities, and that by a very slight force. The result, as might have been expected, was the bursting both of the gun and its case; but that the steel gun or its jacket would have stood the test, if subjected to it singly, cannot be doubted. The difference of expansion between the steel gun and its jacket would be quite enough to account for its bursting. Had the contact of the two been perfect throughout the whole length, but allowing half an inch all around for the expansion of the steel gun in that part which was subjected to the greatest pressure, the very act of restraining it in other parts so as to prevent equal expansion, would be perfectly certain to produce a fracture. Mr. Krupp’s friends have complained loudly of unfair treatment, whether justly or not, no opinion need now be given; but it is much to be regretted that his experiment was not carried out on scientific principles. The introduction of cast steel guns will be the most essential improvement in artillery: and an extensive series of experiments, extending over many years, during which time I have manufactured gun-barrels of steel alone, ought to give my opinion some weight on this subject.

Laminated steel gun-barrels were well known in 1851; but the English bugbear, prejudice, raised a clamour against them, which was echoed by interest and ignorance, and thus their general adoption was for a long time prevented. However, in the short space of seven years, they have become universally adopted, with the most beneficial results; better shooting, less annoyance from recoil, less weight to carry, and greater safety to the sportsman, being the principal. And so it will be with steel cannon; as a short time will suffice to enable scientific investigation to remove all prejudices against them.

The external form of cannon is a question of vital importance, but one which is little understood by artillerists of the present day. Whilst it is a demonstrable fact that all excessive bulk of cast-iron causes weakness in proportion to the excess, no effectual steps have as yet been taken by the Government to ascertain what is the due proportion of metal which ought to exist in different parts of the gun. The American authority on naval gunnery, Captain Dhalgren, has paid considerable attention to this subject; and if the reports on the durability of American heavy ordnance can be relied on (and there is no reason why they should not) his investigations have been attended with much success.

Captain Dhalgren has extended the principle acted upon many years ago by Mr. Monck; his great improvement consisting in lessening the weight of iron in front of the trunnions, and adding to that of the breech. In cannon, as in fowling-pieces, weight in the fore part is useless; conducing neither to the safety of the gun, nor to the smartness of its shooting. For endurance, it is necessary that the expansion should be equal in every part of the gun; rigidity in one part increasing the strain on the immediately adjacent parts, which, if much reduced, are thus rendered liable to fracture. The breech has to endure the lengthened explosion produced by the burning of the gunpowder; and, as this continues until it has overcome the inertia of the projectile, it is necessary in all cases that the maximum of strength should be in the breech of the gun. When the projectile is once in motion the strength of the tube may be rapidly decreased; the only strain it has to bear is exerted whilst the projectile is passing over it; and this strain, in properly constructed guns, becomes of shorter and shorter duration as the projectile attains its highest velocity at the muzzle of the gun. The greatest strain a gun has to bear near the muzzle is that produced by the condensation of the column of air in front of the charge; and in almost every form of English ordnance the weight of metal here is greater than is necessary.

The Russian guns which have been brought to this country present the same superabundance of metal at the muzzle, whilst at the breech there appears to be a deficiency; and when we take into consideration the extraordinary reports of their endurance, we must ascribe it to some other cause than the proper distribution of metal. Their endurance is no doubt owing in part to the goodness of the metal, in part also to the form of the breech, to the uniformity of thickness in the sides of the arch, and, lastly, to the absence of those protuberances called “reinforce rings.” These rings might with propriety be termed “rings of destruction;” for wherever irregularities exist in the substance of the metal, there the waves of vibration are interrupted, and the weak point then becomes fractured. The science of spring-making in all its varieties demonstrates the truth of this statement. Leave on a coach-spring an abutment of metal like a “reinforce ring,” and a few motions will be sufficient to break it, however well the spring may be constructed in every other part. The rigidity of this protuberance, by interrupting the waves of vibration, causes additional vibration in the adjacent and more yielding part, and thus produces fracture. The same thing occurs in all ill-constructed artillery: where the vibrations are checked, there is always a danger of some weaker part giving way. But the laws which regulate the distribution of vibrations in metal substances are not yet understood by artillerists, or cannon would be differently constructed. Those unscientific protuberances called “trunnions,” which are to be seen in almost every description of gun, prove the accuracy of my assertions. These protuberances, if scientifically considered, would soon be discarded, since they tend not only to the rapid destruction of the cannon, but also exert a most injurious influence on the direction of the projectile. The most wonderful shooting ever heard of (and which has been before alluded to) is partly to be attributed to the absence of trunnions. Trunnions act as the fulcrum of a scale-beam; they allow the breech and muzzle of the gun to oscillate, but in an opposite direction to a scale beam. Rifled cannon can never be correctly constructed whilst any weight impinges on the gun in front of the first starting point of the projectile; they must have the fulcrum behind the point of discharge, and the more nearly in a direct line the better.

Rifled cannon will in some few years be perfectly constructed of cast steel; the projectile being made of gun metal, _i. e._, ninety-five parts of copper to five parts of tin, or of lead and its alloys, and at a probable cost of ten times that of a cast-iron projectile of equal weight.

Rifled cannon must be elevated by raising the muzzle; no depression of the breech must occur as by the usual elevating screw; and the recoil must be received and borne by fastenings and axle in rear of the breech only. Trunnions and all impinging influences are incompatible with correctness of fire. The muzzle must be raised in a similar manner to the raising of a hand rifle, the recoil being thrown backwards, in as direct a line as possible with that of the shot.

It is only on account of the difficulty of experimenting with rifled cannon that they are at all behind rifled muskets in point of perfection. The ardent lover of science is appalled when an experiment costs hundreds of pounds. We have not a General Jacob everywhere who can afford to spend a thousand or two in experiments; but, nevertheless, the lover of science, could he experiment, might attain such extraordinary accuracy of range, as to blow up a smaller magazine than that of Kurrachee at four times the distance; and that, too, with a more certain effect, though with a projectile heavier than several of Jacob’s rifles tied together. Correct direction is certain in proportion to the increase of weight; deflection being in the minimum with the heavier weight, from the well known law of momentum. That astute and energetic sovereign, the Emperor Napoleon, is pursuing experiments with rifled cannon; with what result there can be little doubt.

It must be by the use of rifled cannon that our artillery will regain the place it has lost. A short time will suffice to make the disparity between our artillery and small arms as great as when we were content with the six-pounder field gun and old “Brown Bess.” Ranges will only be ruled by sight, and objects will be hit eventually with as much ease at 5,000 yards as they now are at 1,000. Steel, rifled cannon, and projectiles of gun-metal will assuredly bring about as complete a revolution in artillery as the Greenerian rifle and bullet have effected in small arms.

The form of gun best suited for all purposes has yet to be determined; and we have pointed out these defects in our artillery with the hope that some of the great practical philosophers of the present age may devote themselves to the study of this question. It is nearly allied to the science of bell-making, and a few more fractures of Big Ben will extend our knowledge of the subject, and produce a remedy which lies not very deep below the surface. The laws which should guide us in the construction of cast steel guns, so as to insure their durability, are very analogous to those which determine the durability of bells; for the laws which regulate disintegration of crystalline structures are very similar. Hitherto the rule of thumb has, unfortunately, been the only rule observed in measuring out the quantity of metal which shall surround that portion of a cannon which has to sustain the most violent concussion.

Professor Barlow many years ago proved, to the satisfaction of the Institution of Civil Engineers, that the metal in any cylinder decreases in utility in proportion to the square of its distance from the centre: that the outside of a gun of the form now used, in fact, is only one-ninth as useful as the inside; being three times as far from the centre. If we double the thickness, the outside, being five times as far from the centre as the inside, will be but one-twenty-fifth as useful; or in plain English, nearly useless. The reason of this is simple, and I will endeavour to explain it.

“A bar of cast iron one inch thick each way and 40 inches long will stretch about one-twentieth of an inch, if a weight of about four tons be suspended by it. When the weight is removed, the cast iron nearly recovers its previous form, and is uninjured; but if it be stretched more, by a greater weight, it is permanently injured.

“A bar of the same thickness, but three times as long--120 inches--will stretch three times as much, or three-twentieths of an inch, with the same weight; or if only one-third the weight--one ton and a third--be suspended, it will stretch one-twentieth of an inch, the same as the shorter bar.

“If we suspend 16 tons by four bars, one inch thick and 40 inches long, they will each stretch one-twentieth of an inch only, and remain uninjured; but if we attempt to do so with two bars 40 inches long and two 120 inches long, then, when the whole have lengthened one-twentieth of an inch, the short ones are exerting a force of eight tons, but the long ones that of only two and two-thirds tons. The weight, therefore, will still further lengthen the bars, and permanently injure the short ones; perhaps break them first, and then the long ones.

“This is the way a gun is burst. The inside is a series of bars of iron, say 40 inches long, in the form of a ring; the outside a series of rings, representing the bars three times as long.”

Warfare, since the first introduction of gunnery into Europe, has been like one continued series of experiments for testing the efficacy of our guns. No description of gun we now possess can lay any claim to existence fifty years ago: the great majority of our guns now in use are of a much more recent date.

With one or two exceptions, no artillery has been constructed on any scientific theory; some alteration has been made, and if a gun of a certain form and dimensions gave a certain result, then an extension or emulation of that gun was tried; and if it succeeded a loud cry of exultation was raised, and the discovery was announced to the world as a great improvement.

Colonel Prejudice has invented a vastly improved description of gun; another guess is made, and so different forms of guns are multiplied. Can there be a more striking illustration of this than the one which took place during the late Crimean war? It was boasted that the whole human race might be exterminated by the new invention; but the “Lancaster gun” turned out to be most unscientific in its construction, and most eccentric in its action. Had such a thing as scientific knowledge in gunnery existed among the artillerists of the day, such a monstrosity would have been buried soon after its birth; instead of being allowed to squander large sums of money at every discharge, and then at last to become a “Whistling Jemmy” for our bluejackets to laugh at.

The form of cannon no doubt exercises a vital influence over their durability; bad form and imperfection of material combined, tended to produce the rapid destruction of our guns during the late important struggle.

The gun which has been experimented with to the greatest extent, and which has withstood all trials successfully, is a Russian fifty-six-pounder; taken, I believe, at Bomarsund. In this gun there are two great peculiarities; the shape, as will be seen in the diagram, differs from all our own guns: it is a “chambered gun,” and the metal is taken away from the outside precisely as the contraction increases on the inside thus giving an equal thickness of metal in every part, of the arc (see page 114).

In contrast with this, we give a cut of our 8-inch gun, which most nearly resembles it as a chambered gun (see page 114).

The reader’s attention is especially directed to the dissimilarity in the distribution of the metal in the two guns. The want of uniform thickness of metal in our 8-inch gun must be sufficient to convince any one that, if the Russian gun be properly constructed, the principle of ours must be radically wrong. That such is the case, indeed, I cannot doubt, the Russian gun having undergone such a test as would have destroyed six of ours. The gun has since been made two inches larger in the bore, and even oval-bored, for firing shells, which should alone be enough to destroy it; and yet with all this the gun remains perfect.

The gun which most nearly resembles this is our English carronade; and that these guns have some important principle in their shape is proved by their great durability under all trials; and I believe that the tests to which the carronade has been subjected have been more severe than that of any other piece in the British service.

There have been many shrewd conjectures as to the cause of this durability; one of these was very pungent, viz., “the invention was not by one of the cloth.” An examination of the drawing of the 68-pounder carronade will enable the reader to perceive the great similarity between this and the Russian gun before spoken of (see page 114).

The manufacture of these guns was originally in the hands of the inventors, and it is quite evident that they must have taken great pains with the form of the gun, and also have taken special care that the material of which it was constructed was of the very best quality.

There is too much reason to doubt the proficiency of military men in the science of metallurgy; and the British system of depending solely on their knowledge for the last half century, has no doubt proved an obstacle to advancement in the science of gunnery.

The gun which ranks next is Monck’s 56-pounder. Although not a chambered gun, it will be seen, from the diagram (see p. 117), to be an attempt (if not a perfectly successful one) to obtain uniformity of thickness in every part of the arc. The durability of these guns ranks as we have placed them.

The next in rotation is the 8-inch or 68-pounder (see p. 114); which, although not the original sized gun that was rifled for the Lancaster shell, yet it was the one eventually used for that projectile up to the end of its very brief career.

The 10-inch gun of 95 cwt., delineated at page 117, will be seen to be defective in its outlines when tested by the principles before laid down, and the fact of more 10-inch guns bursting at Sebastopol than any others (mortars only excepted), may be taken as exclusive evidence of its imperfection.

The bursting of mortars is quite notorious, especially the 13-inch mortars used for sea-service in the attack on Sweaborg. A slight examination of the engraving of one will be sufficient to convince any person that, if what has already been advanced on the form of guns can lay claim to being scientific, then this is of all guns the most unscientific that was ever manufactured. Its durability, too, like its shape, is of a very low order.

The 13-inch land mortar depicted below is a much more serviceable production, because it contains much less metal.

Mortars will retain their place in spite of all improvements. Rifling is inapplicable to them. Their principal utility consists in obtaining a vertical fire; the shell being pitched to a great height, so as to fall into places that cannot be assailed by a horizontal fire.

The late Joseph Manton has the merit of being the first modern inventor of rifled cannon. His idea was, that if a motion on an axis parallel to the horizon could be given to cannon balls, they would range farther and with greater accuracy. As there exists great difficulty in causing the rifling in a gun to act upon an iron ball, he constructed a cup of wood, into which the ball was fitted, projections being made upon the wood to fit into the groves of the rifle; the spinning motion thus being communicated to the ball by its wooden adjunct. The result was twofold; for the expansions of the wood during the explosion, filled the tube of the gun tight, and effectually destroyed the windage. The government of the day did offer him a premium of one farthing each; but “Joe” over-reached himself, asking the sum of £30,000 down; this was refused, and the patent was allowed to expire without the Government taking any advantage of it, and experiments ceased to be made in this direction.

Rifled cannon have now, however, become a certainty. Mechanically speaking, they are as easily to be produced as hand rifles. The general application has, however, vast difficulties, which must be overcome before their use can become general. Small arm projectiles suitable for rifles must of necessity be made of ductile metal, and all the attempts previously made, whether with brass or iron guns, are alike useless. The mass in motion, even when of equal hardness with the gun (as in the case of cast iron guns and cast iron shot), invariably destroys that in a comparative state of rest; and the rifling is obliterated after a very few discharges. In a brass gun the destruction is certainly not so rapid, on account of the different nature of the metal; yet the destruction of the gun for all useful purposes is equally effectual. It is evident, then, that success cannot be obtained by using the present materials in rifled cannon; and the question inevitably arises, what better material can we use? Wrought iron shells have already been thoroughly tried in the Lancaster oval gun, with a well-known result.

Great hopes were at one time entertained, that something suitable would result from Mr. Bessemer’s discovery of the combustion of carbon, and that an iron of sufficient ductility, yet without the usual hardness, would be produced; but this, it appears, is still a myth.

Extent of range and accuracy of fire in gunnery will in future be of so much importance in war, that it is not extravagant to assert, that in contests between well-matched belligerents, the precious metals (if they gave any advantage to the user) would be unhesitatingly used in projectiles. But on the score of economy, science need not be impeded. Gun-metal projectiles and cast steel cannon would work as effectually together as lead and iron in small arms.

Some other mixtures less expensive might be produced (lead and copper in certain proportions are very ductile), and at the same time sufficiently strong to resist all tendency to squash; as the softer metals would inevitably do. The more ductile metals are limited in their utility, by the same law which limits the use of pure lead: that is, to given weight, height of column, or velocity. Great doubt exists whether a bullet made of gun metal, and of the same proportionate dimensions and form as an Enfield bullet, but fitted for a ten-inch gun, would not, if fired with the proportionate charge of powder (namely, seventeen pounds), be as completely squashed, or driven in upon itself, as the Enfield bullet if fired with the old Brown Bess charge of four drachms and a half.

Considerable time and experience will be required to ascertain the proportions of metallic mixture necessary to meet all contingencies; this, however, is a matter of detail, and must extend over so large an area, that it can be handled only by the government officials, with the necessary “sinews” of experiment. Nevertheless it must be undertaken; and the sooner it is done the better, for the prestige of that nation which would lead the van of improvement in gunnery, and increase its power of attack and defence beyond those of its rivals.

Rifled cannon is a generic term of endless application, presenting to the mind modifications of projectiles in endless variety, ranging from the “_light firebrand_” to the twice deadly rocket: not rockets of that eccentric and erratic character by which Congreve made an undying name; but real _bonâ fide_ rifle rockets, which shall hit the dead-lights in the quarter-gallery of a frigate, carry away the halyards of your enemies’ ensign (making him drop his colours at the first shot) or dash the glass from the hand of the pilot. All such imaginary feats will yet be accomplished; though the reader may smile at the idea. My experience with rockets goes to justify me in asserting that rockets discharged from a gun, under certain circumstances, can be as effectually controlled, and kept to a direct course, as a bullet fired from a rifle. The rocket, however, may be fired a much greater distance than we have ever been able to project a bullet; because, in addition to the force which projects it from the gun, its flight is maintained by the self sustaining agency in the body of the rocket. Rockets require a much smaller charge of powder to project them than that which is used for a bullet; a rocket started by its own force, expends, in acquiring even an approximation to its highest velocity, at least one-third of the force with which it is charged; but when projected by a small charge of gunpowder this force is saved, and the flight of the rocket is afterwards sustained by the force with which it is charged.

Firing rockets from cannon can only be practised under certain circumstances. The observations already made on the granulation of gunpowder will have prepared the reader for this announcement. When fired from a cannon under the old régime, the rocket was projected at high velocity, and the case of the rocket was destroyed by the very force which set it in motion. A rocket suitable for artillery should be cast of gun metal, with a frame of considerable strength. In form it should nearly approximate to an expansive bullet; but, instead of the limited length of one and three quarters diameter; it should approach to four diameters; two of which, at least, should be appropriated to the cylinder behind the head.

The head is charged with composition more densely driven than is customary in the ordinary rocket; the tubes in the cylinder are also charged with a composition equally dense. The outer frame of the rocket is cast with suitable projections to fit the grooves of the gun: the spiral of these grooves is considerable, being one turn in every three feet, in order to impart to the rocket an effectual spinning motion when in a low state of velocity. The rocket properly constructed is then placed in the rocket-gun, and fired in the usual way; but it is essential that the gunpowder used should be of a suitable quality: its combustion must be as slow as possible, a starting velocity of from 500 to 800 feet per second being sufficient to ensure the flight of the self-sustaining projectile to the end of its range. This principle may be extended from a light firebrand, as already stated, to that of a rocket charged in the head with the most deadly and destructive fulminate.

It may appear absurd to speak of fulminates being projected; since all experiments show that fulminates, even when adulterated, will not stand the concussion of a discharge, but invariably ignite in the gun, however carefully placed or packed in the shell which contains them: for this reason fulminates have never been successfully used. But if the fulminate is placed in the head of a rocket, this objection may be obviated. The gradual manner in which velocity is given to a rocket does not subject it to violent displacement during its flight; neither need the concussion in the gun be severe, owing to the nature of the gunpowder used, which in its gradual expansion is analogous to steam: thus the field for the application of fulminates is opened to an unlimited extent.

My own experience on this subject has been limited to its application for the saving of life from shipwreck, where the application of a line to the rocket limits its range and velocity; but sufficient is left in a rocket of an inch and a half diameter effectually to carry out a line of a quarter of an inch diameter to a distance of 600 or 800 yards: that is, more than double the distance obtained by either Manby’s apparatus or the rockets now in use; which, lamentable to state, are quite inadequate to the purposes for which they are intended.

Though the improvements in rifled cannon are at present only in their infancy, they have nevertheless attained to an extraordinary degree of perfection, verifying all our predictions to the letter.

A writer in the _Times_ makes the following statements in favour of Mr. Whitworth’s improvements:--

“While some men of really inventive talent, and a great many charlatans, have been permitted to waste the public money in trying vainly to improve our artillery, it seems passing strange that it should not long ago have been discovered how impossible it was to hope for successful results in the direction in which they were working. It was clear that while increased range and precision of firing were wanted, it was nearly as important to bring the charges of ammunition and the weight of metal in guns into more manageable proportions to each other, and to the facilities for transit on active service. No sensible man can have witnessed the frightful damage done to the efficiency of our army in the Crimea by the exigencies of the siege-train during the winter of 1854-5 without being impressed with this conviction. The principle of the rifle offered an obvious suggestion for the proper means of working out the foregoing problem; but then for artillery, rifling by grooves would not do without the use of a pliant metal in the projectile, and the cost of lead rendered its application to that purpose impracticable. It was necessary, therefore, to alter the existing mode of rifling, and to modify the bore of the cannon, so that an iron projectile could be discharged from it, rotating on its own axis in the line of flight. This result once secured, it is obvious that a field-piece or gun of position would become a rifle on a large scale, and that the same immense increase of range and of penetration which had been realised by the smaller weapon as compared with Brown Bess, would be placed at the command of the artillery service. It is consolatory, after a series of failures worthy even of Brunel in launching the _Leviathan_, that the country has at last the well-grounded hope of an improvement by which our ordnance may be placed on a proper footing. In pursuing those careful experiments which he undertook for the Government, principally to improve the rifle, Mr. Whitworth, the eminent machinist, adopted a polygonal spiral bore of a uniform pitch, but more rapid than could be attained by grooves. This bore has enabled him to surpass immensely the range and penetration of the Enfield rifle; but even these advantages, important as they are, scarcely surpass those which it places within the reach of our artillery service. The strain of the projectile being distributed evenly over every side of the polygon, iron can be substituted for lead in the projectile, and this simple but beautiful mechanical appliance at once becomes available for cannon.”

The powerful aid of the _Times_ is “almost success;” though in this instance it has signally failed, the boasted accuracy there spoken of not having been yet obtained. This has no doubt arisen in part from the fact that Mr. Whitworth’s great mechanical knowledge would not suffice to make him _au fait_ at the compound science of gunnery. His “polygonal spiral bore of uniform pitch, more rapid than could be obtained by grooves,” is after all only an experimental gun, not sufficiently developed as yet for practical utility. Still, the writer already alluded to has favoured us with the following remarks in the _Times_:

“Moreover, Mr. Whitworth has discovered in the course of his experiments, that according to the quickness of the turn in the polygon is the length of the projectile that may be fired; so that 24 lb. and 48 lb. shot have been sent to extraordinary ranges with half the usual charge of powder, from an ordinary 12-pounder howitzer. Here, then, is at once the solution of the whole question which has troubled the brains of so many inventors, real or pretended, for years. The artilleryman at one stride resumes the relative position to the soldier of the line which the Enfield rifle had so perilously deprived him of, and this mechanical country, after finding herself on the level of France, Russia, and other European States, is once more, as during the Peninsular campaigns, enabled to assert her natural superiority in the manufacture of cannon. We trust that no petty jealousies on the part of narrow-minded officials will be allowed to interfere with the course of Mr. Whitworth’s experiments, and that the encouragement which he is now receiving from the Minister at War and the Commander-in-Chief will enable him, at no remote date, to realise for the benefit of the army and the nation that revolution in gunnery which the results already obtained by him promise.”

Report says that 25,000_l._ is the amount of encouragement Mr. Whitworth has received from the Minister of War and the Commander-in-Chief; an adequate sum with which to conduct such an experiment, but not sufficient to insure success.

Of the success of Mr. Whitworth’s polygonal projectile, on a large scale, none need speculate, for the principle is self-destructive.

Lancaster’s oval shell, oscillated in its flight, took a flight so extraordinary, on account of the resistance of the atmosphere on the protuberances of the oval, that the principle may be regarded as fully established that enlarged projectiles must be smooth and free from projections that “saw the air,” otherwise range and accuracy of fire will be sacrificed. The principle of Mr. Whitworth’s polygonal bore is fully discussed in its proper place, and will here receive only a passing notice.

To Mr. W. G. Armstrong, of Newcastle-upon-Tyne, much more credit is due than can be claimed for Mr. Whitworth. Long before the paid efforts of Mr. Whitworth, Mr. Armstrong had made the subject of rifled cannon a special study, and the success of his investigations has been such as to couple his name with those of the earliest inventors of effectual rifled cannon. Mr. Armstrong may also lay claim to being an originator of wrought steel cannon; though here his name stands second as an inventor, for to Mr. Krupp is due the honour of first introducing cast steel cannon to the notice of our Government.

Mr. Armstrong tells his own tale so well in the columns of the _Times_ that we cannot do better than quote it:--

“In the latter part of 1854, I submitted to the Duke of Newcastle, then Minister at War, a proposal for a gun which I anticipated would possess great superiority over the common forms of light artillery, and I undertook, with his Grace’s authority, to construct a field-piece in conformity with the plan I had suggested. The gun was accordingly soon afterwards made, and has since, during a period of nearly two years, been the subject of numerous experiments, partly upon the ordnance firing-ground at Shoeburyness; but principally under my own direction in this neighbourhood.

“I have hitherto avoided publicity in reference to these experiments, but, as matured results of much interest and importance have now been arrived at, and as other names are already before the public in connection with gun experiments made during the same period, I feel that I may now, without impropriety, give some information on the subject.

“With a view to strength and durability, the gun is composed internally of steel and externally of wrought iron, applied in a twisted or spiral form, as in a musket or fowling-piece. The bore is nearly two inches in diameter, and is rifled. The projectile is a pointed cylinder 6-1/2 inches long, and its weight is 5 lb. It is made of cast iron, coated with lead, and is fired from the gun with a charge of 10 ounces of powder; it contains a small cavity in the centre, and may be used either as a shot or a shell. When applied as a shell, the cavity is filled with powder, and a detonating fuse is inserted in front, so as to fire the powder in the centre on striking an object. When used as a shot, the powder is omitted, and an iron point, which favours penetration, is substituted for the fuse. The gun is constructed to load at the breech, the object being not only to obviate the disadvantages of sponging and loading from the front, but also to allow the projectile to be larger in diameter than would enter at the muzzle, and thus to insure its taking the impress of the grooves and completely filling the bore. The piece weighs 5 cwt., and is mounted upon a carriage which bears a general resemblance to that of an ordinary 6-pounder field gun, but which embraces a pivot frame and recoil slide. A screw is also applied, not only for elevating and depressing the gun, but also for moving it horizontally, by which means great delicacy of aim is effected. The recoil slide has an upward inclination, which enables the gun, after running back, to recover its position by gravity; and its use is to relieve the pivot-frame and adjusting screws from injurious concussion.

“I shall now give some particulars of the experiments recently made with this gun on the coast of Northumberland, near the village of Whitley, under the official inspection of Colonel Wilmot.

“Fourteen shots were in the first instance fired from a distance of 1,500 yards at a timber butt, 5 ft. wide 7-1/2 ft. high. Six of these were expended in finding the elevation proper for the distance, but after that was determined every succeeding shot hit the object without previous graze. The final elevation of the gun was 4 deg. 26 min., and the mean lateral distance of the shot-marks from a vertical line through the centre of the butt was only 11-1/2 in.

“Persons who are conversant with artillery practice will be able to appreciate the accuracy of this firing; but, for the information of those who are unacquainted with the subject, I may state that the ordinary 6-pounder field-piece, which in point of weight forms the nearest approach to the present gun, is perfectly useless at a distance of 1,500 yards, and is very uncertain even at 1,000 yards. It is only, therefore, with heavy artillery that a comparison can be drawn; and it will be sufficient to state that in tabulating the practice made with such ordnance the deflections are invariably recorded in yards, whereas with this rifled gun they can only be properly given in inches.

“With respect to penetration, the following particulars will be regarded as equally remarkable, considering the small weight of the shot and the length of the range. The butt was 3 ft. thick, and was composed of six layers of rock elm bolted together, so as to form a solid block. One shot passed entirely through; another struck near the edge and glanced; and the remaining six penetrated within a few inches of the opposite side.

“Shell firing was next tried at a distance of 1,500 yards; the gun being fired at the same elevation and with the same charge as in the previous practice at the butt.

“In this case two targets were erected, one behind the other, so as to appear as one object when viewed from the gun, and a space of 30 feet was left between them. The front target was intended to exhibit the perforations of the shell before bursting, and the back one to show the effect of the fragments resulting from explosion.

“After some preliminary experiments twenty-two shells were fired at the front target, and of these only one missed the object of aim. The following are the particulars:--Seventeen hit the first target direct, and burst behind it, the fragments penetrating the second one; three grazed and burst immediately in front of the first target, and perforated both with the pieces; one hit the bottom of the first target and exploded in the ground, and the remaining one missed entirely and burst on some rocks nearly on line beyond. A strong side wind was blowing at the time, and accounted for the deviation of this single shell.

“Four shells and three shots were then fired at an elevation of 6 degrees, from a distance of 2,000, or, more accurately, 1,964 yards. All these struck within the breadth of the target; but the elevation being scarcely sufficient, they all fell a little short, except one shell, which, ranging somewhat further than the others, hit the target and burst as usual.

“The results of this shell-firing were as follows:--The front target contained 51 holes, and the back one 164, while the ground between and adjacent to the targets exhibited about 70 perforations by fragments of shells, the greater portion of which were afterwards recovered by digging.

“With respect to ranges exceeding 2,000 yards, I may state that on previous occasions the gun had been tried up to 3,000 yards--a distance which was reached with an elevation of 11 deg., and the usual charge of 10 ounces of powder, or 1-8th the weight of the projectile. By augmenting the charge the range is increased, but the accuracy is impaired; and I therefore adhere to the 10-ounce charge, which gives ample penetration, as the experiments at the butt will testify. I may also observe that the ranges obtained with this charge bear a favourable comparison with those of the heaviest round-shot guns fired with a much larger proportion of powder.

“It is a curious fact, and one which greatly increases the efficiency of the shells, that owing to the bursting charge requiring a minute space of time to mature its ignition after the firing of the fuse by impact, the shell is enabled to travel four or five feet after striking an object before disruption takes place. Hence, therefore, it acts as a shot before it bursts as a shell. When it perforates a target the explosion may be seen to take place at a few feet beyond, and when it grazes it has time to rise, and may be observed to burst after clearing the ground. If, therefore, it were fired against a ship, it would first penetrate the side in its entirety, and then, bursting, traverse the deck in fragments; or if directed against troops, it would pierce the front line as a bullet, and operate like grape-shot beyond. The shells explode with equal certainty whether the first substance struck be hard or soft; and, in fact, they even burst on the surface of water, provided the elevation of the gun be not too great. The bursting charge is very small, but it suffices to break the shell into about 30 pieces, which pursue their forward course without too much dispersion.

“It is impossible to contemplate the results obtained with this gun without being impressed with the important part it is calculated to perform in warfare. Opposed to any ordinary field-piece, it would be like the Greener rifle against the old musket; and no gun could be worked at an embrasure if a fire of shells were directed against it by one of these rifled pieces placed within the distance of a mile. In naval operations, also, guns of this description, but of larger size, might apparently be applied with great effect--more especially as a system of breech loading, combined with a self-recovering recoil action, would be peculiarly advantageous in firing from portholes. Even light 5-pounders, sending their shells from great distances through the sides of a ship and sweeping the decks with fragments of lead and iron, would produce very destructive effects; and a small swift steamer carrying a few such guns might prove a very troublesome opponent to a large ship of war. But if the dimensions of the gun were increased so as to adapt it for shells of 20 lb. or 30 lb., still more terrible injury could be inflicted at greater distances; and the ponderous artillery now used at sea would be of little service when opposed to the accurate and long-range firing of such rifled shell-guns.”

Since the publication of these remarks, rifled artillery of Mr. Armstrong’s production has, we believe, been extensively tried. The results of these trials have been most extraordinary; and the principle is, we believe, identical with the expansive principle bearing my cognomen: an extension of the principle of the Greener and Enfield rifle, hereafter to be described. I have had the honour of being consulted both by English and foreign authorities, and I have assisted in constructing rifled artillery for several years; and the experience thus obtained justifies me in making known to the world some of my observations on this subject.

Rifled cannon with elongated projectiles, similar in shape and principle to the Greenerian bullet, give, with charges inferior to those of the old régime and calibre, more than double the range, with ten times greater accuracy.

Now, either of these points, if gained, would be most important improvements, and when combined would produce the most extraordinary results. But this is not all: a great diminution in the weight of the gun might also be effected; and these advantages may be still further extended when we have had time to increase our knowledge of the valuable materials with which we are only just now becoming acquainted.

The following table will show the advantages to be gained both in length and accuracy of range.

Before reverting to the table, it may be necessary to remind the reader that the great reduction in the weight of guns arises from the adoption of the elongated projectile. For example: the diameter of the _elongated_ projectile for an “18-pounder” is much less than the diameter of the gun for the _spherical_ 18-pounder; thus allowing the thickness of metal to be equal in both guns. The gun for the elongated projectile may be greatly reduced in weight without at all diminishing its strength, simply on account of the great diminution in the diameter of the arc.

There is another important fact, which Mr. Whitworth, with all his boasting, has carefully concealed: viz., that a much greater pressure is exerted upon the square inch in the lesser than in the larger diameter of bore; and to conceal this fact, whilst claiming merit for a bullet of 50-gauge exceeding in range one of 25-gauge, the charge of gunpowder being alike in both cases, appears very like deception. Any engineer will tell us that the pressure in the lesser is twice as great as in the larger bore; and this explains why greater velocity is given to the projectile.

With these explanations the reader will be better prepared to weigh carefully my observations. My task would, doubtless, have been rendered more easy, if a clear elucidation of the principles of the expansive bullet could have been given thus early in the work; but it is thought better to do this in its proper place. I will only add here, that although two bullets, one elongated, the other spherical, and of equal diameter, meet with the same amount of atmospheric resistance, yet the one containing twice as much matter as the other retains its medium velocity nearly double the distance. With these explanatory remarks I give the following table:--

------------------+-------------+-------+--------------+---------- |Present Range|Present|Reduced Weight|Range when |of Guns. |Weight.|when Rifled. |Rifled. ------------------+-------------+-------+--------------+---------- 6-pndr. | 1,500 yds. | 17 | 12 cwts. |3,000 yds. 9-pndr. | 1,600 „ | 26 | 18 „ |4,000 „ 12-pndr. | 1,700 „ | 34 | 22 „ |4,500 „ 18-pndr. | 1,780 „ | 42 | 29 „ |5,000 „ 24-pndr. | 1,850 „ | 50 | 34 „ |5,500 „ 32-pndr. | 2,000 „ | 63 | 42 „ |6,000 „ 48-pndr. | 2,500 „ | 70 | 45 „ |6,500 „ 56-pndr. | 5,000 „ | 85 | 60 „ |8,000 „ 68-pndr. or 8-in. | 4,500 „ | 85 | 60 „ |8,000 „ 86-pndr. or 10-in.| 4,700 „ | 95 | 65 „ |9,000 „ ------------------+-------------+-------+--------------+----------

The reader must understand that all the guns given in this table were not rifled, and that they have not all been subjected to trial. The 6, 12, 18, 24, and 48-pounders have been tried, with the results given above; but the heavier guns have not as yet been tested: the ranges and weights given in the table have, however, been derived from the results yielded in the trial of the lesser guns, and may be safely relied on as scientific data; being, in truth, rather under than over the mark.

All experiments clearly establish one very important principle, long known to those acquainted with the science of projectiles, viz., “That the heavier the projectile, the less the deflection.” Thus it is quite possible that the longest ranges may ultimately be obtained without any perceptible deflection. And when we observe that the deflection of an ordinary 32-shot in a range of 2,000 yards, is 50 feet, and in 2,500 yards, 80 feet, whilst the elongated shot, at a much greater distance, is not deflected half as many inches, I think we may fairly say that our knowledge of gunnery is yet in its infancy. Fulminating powder may be used as an auxiliary in shells for various important purposes; such, for instance, as destroying an entire fleet; and it is clearly within the range of possibility that by its agency the largest ship may be destroyed by a single shot. The accuracy of rifled cannon renders it an easy task to strike a plank only one inch above the water line, and the penetration of an elongated gun-metal or lead-alloyed shell would enable us to reach the innermost parts of the magazine: for it is scarcely possible to produce even an iron casing which shall resist the power of such projectiles. It is possible, therefore, that we may see the noblest fleet destroyed in a few minutes by the agency of such projectiles.

I will endeavour to give an outline of the method by which this may be effected. A long rifled cannon, constructed for an elongated gun-metal shell; of from fifty-six to eighty-six pounds, and with an extreme range of from 6,000 to 7,000 yards, may be considered to be a suitable instrument. This shell should be charged in the head with a given quantity of the fulminate, such as would be most calculated to prevent the tendency to explode from the concussion produced by the discharge of the gun. It will be necessary to place the fulminate in thin layers between sheets of prepared caoutchouc, or some other preparation of India-rubber; having thus arranged the fulminate in the head of the shell and secured it there, the usual method of filling the remainder is resorted to, and the aperture is securely screwed up: fuses not being necessary in this arrangement.

The difficulty in using this shell is to prevent its explosion when the gun is discharged; and to obviate this all our engineering skill is required. Time and experience will show that, by a modification of the propelling agent, the shell may be started from a rifled cannon at a very low velocity; the velocity being increased like that of the rocket. This is to be done by modifying the arrangement of the gunpowder so as to ensure the shell acquiring its greatest velocity as it leaves the muzzle of the cannon. The result of this has been already shown. On the shell striking any object, such as the ship’s side, the metal of the shell is driven in upon itself, and an explosion of the fulminate follows as a natural consequence. Experiment has proved that shells exploding as they strike the ship’s sides, produce very little damage beyond making a hole in the ship the size of the shell. This, no doubt, arises from the short space of time occupied by the shell in passing through the side of the ship; all its force being exerted in the interior instead of on the sides of the vessel. All shells of the nature alluded to would, at certain distances, take such a line of flight as to ensure them dipping towards the centre of gravity, and thus exploding the magazines, however deep below the water-line; and when we consider the destructive effects of fulminates, we think it quite within the range of probability that they might produce all the effects we have spoken of.

There are many agents equally powerful to be introduced into destructive warfare; and with the advantages to be derived from improvements in rifled shells, which the ingenuity of the present race will certainly effect, he would be a rash man who would set any limits to the advancement of projectile science. The great difficulty in the use of fulminates will be surmounted if these suggestions can be carried out; and experiment is all that will then be necessary to establish the line of proceeding. To effect this is the province of the Government of the country; to wait for it to be perfected by individual skill and enterprise would be unjust to science, and injurious to the best interests of the nation. The needful expenditure can only be borne by the nation, and should be entered upon, in order to effect improvement in projectiles, with the view of maintaining our land and marine artillery at the highest point of efficiency.

There is one question of great importance to inventors, and to which I have paid much attention, namely, the obtaining a spiral motion in a projectile which has been fired from a smooth bored gun. All we have witnessed goes far to prove that the attainment of this is impossible, in consequence of a principle not hitherto investigated by inventors. If the course of a projectile is changed from the straight to the spiral, it can only be done at the expense of range; and that for the following reasons: first, the force which is necessary to induce this spiral movement must be exerted at the expense of the force which propels it forward; secondly, when this spiral movement is acquired, it is so much in excess of the direct movement, that after advancing a certain distance it falls to the ground. A very simple experiment will prove this. Take an ordinary tin tube, cut a bullet of an elongated form--cylindro-conical if wished--having grooves from the point backwards, with the degree of spiral necessary to effect the object in view. Let the bullet be made of cork or light wood, such as can be projected by a blast from the mouth, and the result will be that the projectile will go one-half the distance before the friction of the atmosphere produces a motion on its axis parallel to its line of flight; from this point it gradually loses its velocity in a forward direction, it spins until its force is expended, and then falls vertically to the ground. To find the sequel, try the same experiment without grooving, and the range, with the same force, will be found to be double. Some years ago I witnessed such a trial with a 32-pounder; and, to the astonishment of all present, the bullet rose above the horizontal line, and then fell to the ground, like the cork bullet of which we have already spoken.

The endeavour to produce breech-loading cannon is an effort to obtain uncalled-for and superfluous facility in gunnery; and if a perfect breech-loading cannon could possibly be produced, what would it avail? What superior property could it possess over the solid gun? It could not be safety; for when we consider the very limited number of explosions by which the very best guns are destroyed, it can scarcely be possible for a gun composed of many parts to endure the intense vibrations to which large cannon are subjected. The regular distribution of vibrations in the metal of the gun is the great point to be attended to in the construction of artillery; so that vibrations may not be incorrectly induced by malformation, or by an excess or deficiency of metal at any particular point; for where the waves of vibration are checked by an unequal distribution of metal, or other causes, there the weak point in a gun is always found, as all fractured guns clearly demonstrate. An intimate acquaintance with the metallurgy of cannon, enables me to give an almost unerring opinion as to the causes leading to the fracture. Most undoubtedly, vibration, if judiciously distributed, is the soul of endurance; but if injudiciously distributed is certain to result in the destruction of the cannon. In structures composed necessarily of many joints, obstruction to the waves of vibration must occur; the different parts do not expand and vibrate equally; a kind of revulsion is induced; part repels part, and destruction ensues as a natural consequence. Under no circumstances, therefore, can a breech-loader be as safe as a solid gun.

The facility with which breech-loaders can be charged is generally trumpeted forth to the world as an advantage of vital importance; but let us carefully examine this point and see if it has not been exaggerated--whether, in fact, a solid gun cannot be charged and discharged as rapidly as a breech-loader.

In the first place, all guns recoil; this necessitates the relaying of the gun after every discharge, in order to obtain accuracy of aim; and if facility of loading is to be obtained at the expense of aim, it can scarcely be called an advantage. Aim consumes more time than loading. A six-pounder may be loaded and fired six times in the first minute; but it would be impossible to do this and re-lay the gun after each shot. Where then is the advantage of firing six shots per minute if you cannot hit six objects? And if breech-loaders could be fired _sixty_ times per minute, what would they avail if aim was wanting? The raising or depressing of the breech of a gun by means of the elevating screw; slewing to the right or left, spunging the gun, and ramming home the powder and shot, all consume time; hence we think that quickness of loading is worthless.

Breech-loading cannon cannot be constructed for bullets of larger diameter than that of the rifle bore, without a ductile bullet be used; for, as is usual in breech-loading small-arms, the bullet rifles itself as it is forced up the grooves. The projectiles for rifled cannon have hitherto been cast with corresponding grooves and lands to fit the internal form of the cannon. A compound shot, composed of iron, and covered externally with ductile metal, has been tried in a few instances; but, unfortunately, the difficulty of combining two metals so dissimilar as iron and lead has been found so great as invariably to end in a failure; therefore no prospect exists of bringing into play this, the best point existing in breech-loading arms.

Lastly, the tendency of all guns to absorb the heat, developed during explosion, puts a limit to all extreme rapidity of fire; even if this was not already limited by the more essential point of taking aim. At Sweaborg it was found necessary to allow an interval of five minutes between each discharge of a mortar, and yet the whole of them burst after an average of 120 shots. Time and ingenuity spent in planning and constructing breech-loading cannon will always end in disappointment and failure. Many are the plans extant, evincing great skill, perseverance, and everything needful in point of mechanical experience, but betraying a total ignorance of the metallurgic science and of practical results from the use of the engine. The study of these points will save money, time, and what is of more value, brain-work, which might be better employed. Striving to produce perfect breech-loading cannon is like striving to square the circle.