Chapter XI: Introduction (9)

One of the survivors, Mr. James May, a gunner, related that, shortly after midnight he was roused from his sleep by a noise, and feeling the ship uneasy, he dressed, took a light, and went into the after turret, to see if the guns were all right. He found everything secure in the turret, but that moment he felt the ship heel steadily over, and a heavy sea having struck her on the weather side, the water flowed into the turret, and he got out through the hole in the top of the turret by which the guns were pointed, only to find himself in the water. He swam to the steam-pinnace, which he saw floating bottom upwards, and there he was joined by Captain Burgoyne and a few others. He saw the ship turn bottom up, and sink stern first, the whole time from her turning over to sinking not being more than a few minutes. Seeing the launch drifting within a few yards, he called out, “Jump, men! it is your last chance.” He jumped, and with three others reached a launch, in which were fifteen persons, all belonging to the watch on deck, who had found means of getting into this boat. One of these had got a footing on the hull of the ship as she was turning over, and he actually walked over the bottom of the vessel, but was washed off by a wave and rescued by those who in the meantime had got into the launch. It appears that Captain Burgoyne either remained on the pinnace or failed to reach the launch. Those who were in that boat, finding the captain had not reached them, made an effort to turn their boat back to pick him up, but the boat was nearly swamped by the heavy seas, and they were obliged to let her drift. One man was at this time washed out of the boat and lost, after having but the moment before exclaimed, “Now, lads, I think we are all right.” After twelve hours’ hard rowing, without food or water, the survivors, numbering sixteen men and petty officers and three boys, reached Cape Finisterre, where they received help and attention. On their arrival in England, a court-martial was, according to the rules of the service, formally held on the survivors, but in reality it was occupied in investigating the cause of the catastrophe. The reader may probably be able to understand what the cause was by giving his attention to some general considerations, which apply to all ships whatever, and by a careful examination of the diagrams, Figs. 74 and 75, which are copied from diagrams that were placed in the hands of the members of the court-martial. The letters b and g and the arrows are, however, added, to serve in illustration of a part of the explanation. The vessel is represented as heeled over in smooth water, and the gradations on the semicircle in Fig. 74 will enable the reader to understand how the heel is measured by angles. If the ship were upright, the centre line would coincide with the upright line, marked o on the semicircle, and drawn from its centre. Suppose a level line drawn through the centre of the semicircle, and let the circumference between the point where the last line cuts it and the point o be divided into ninety equal parts, and let these parts be numbered, and straight lines drawn from the centre to each point of division. In the figure the lines are drawn at every fifth division, and the centre line of the ship coincides with that drawn through the forty-fifth division. In this case the vessel is said to be inclined, or heeled, at an angle of forty-five degrees, which is usually written 45°. In a position half-way between this and the upright the angle of heel would be 22½°, and so on. The reader no doubt perceives that a ship, like any other body, must be supported, and he is probably aware that the support is afforded by the upward pressure of the water. He may also be familiar with the fact that the weight of every body acts upon it as if the whole weight were concentrated at one certain point, and that this point is called the centre of gravity of the body. Whatever may be the position of the body itself, its centre of gravity remains always at the same point with reference to the body. When the centre of gravity happens to be within the solid substance of a body, there is no difficulty in thinking of the force of gravitation acting as a downward pull applied at the centre of gravity. But this point is by no means always within the substance of bodies: as often as not it is in the air outside of the body. Thus the centre of gravity of a uniform ring or hoop is in the centre, where, of course, it has no material connection with the hoop; but in whatever position the hoop may be placed, the earth’s attraction pulls it _as if_ this central point were rigidly connected with the hoop, and a string were attached to the point and constantly pulled downwards. This explanation of the meaning of centre of gravity may not be altogether superfluous, for, when the causes of the loss of the _Captain_ were discussed in the newspapers, it became evident that such terms as “centre of gravity” convey to the minds of many but very vague notions. One writer in a newspaper enjoying a large circulation seriously attributed the disaster to the circumstance of the ship having lost her _centre of gravity_! The upward pressure of water which supports a ship is the same upward pressure which supported the water before the ship was there—that is, supported the mass of water which the ship displaces, and which was in size and shape the exact counterpart of the immersed part of the ship. Now, this mass of water, considered as a whole, had itself a centre of gravity through which its weight acted downwards, and through which it is obvious that an equal upward pressure also acted. This centre of gravity of the displaced water is usually termed the “centre of buoyancy,” and, unlike the centre of gravity, it changes its position with regard to the ship when the latter is inclined, because then the immersed part becomes of a shape different for each inclination of the ship. Now, recalling for an instant the fundamental law of floating bodies—namely, that the weight of the water displaced is equal to the weight of the floating body—we perceive that in the case of a ship there are two equal forces acting vertically, viz., the weight of the ship or downward pull of gravitation acting at G, Fig. 74, the centre of gravity of the ship, and an equal upward push acting through B, the centre of buoyancy. It is obvious that the action of these forces concur to turn a ship placed as in Fig. 74 into the upright position. It is by no means necessary for this effect that the centre of gravity should be below the centre of buoyancy. All that is requisite for the stability of a ship is, that when the ship is placed out of the upright position, these forces should act to bring her back, which condition is secured so long as the centre of buoyancy is nearer to the side towards which the vessel is inclined than the centre of gravity is. When there is no other force acting on a ship or other floating body, these two points are always in the same vertical line. The two equal forces thus applied in parallel directions constitute what is called in mechanics a “couple,” and the effect of this in turning the ship back into the upright position is the same as if a force equal to its weight were applied at the end of a lever equal in length to the horizontal distance between the lines through B and G. The righting force, then, increases in proportion to the horizontal distance between the two points, and it is measured by multiplying the weight of the ship in tons by the number of feet between the verticals through G and B, the product being expressed in statical foot-tons, and representing the weight in tons which would have to be applied to the end of a lever 1 ft. long, in order to produce the same turning effect. When a ship is kept steadily heeled over by a side wind, the pressure of the wind and the resistance of the water through which the vessel moves constitute another couple exactly balancing the righting couple. The moment of the righting couple, or the righting force, or statical stability as it is also called, is determined by calculation and experiment from the design of the ship, and from her behaviour when a known weight is placed in her at a known distance from the centre. Such calculations and experiments were made in the case of the _Captain_, but do not appear to have been conducted with sufficient care and completeness to exhibit her deficiency in stability. After the loss of the ship, however, elaborate computations on these points were made from the plans and other data. The following table gives some of the results, with the corresponding particulars concerning the _Monarch_ for the sake of comparison:

┌───────────────────────────────────────────────┬──────────┬──────────┐ │ │_Monarch._│_Captain._│ ├───────────────────────────────────────────────┼──────────┼──────────┤ │ I. Angle at which the edge of the deck is │ 28° │ 14° │ │ immersed │ │ │ │ II. Statical righting force in foot-tons at │ 12,542 │ 5,700 │ │ the angle at which the deck is immersed │ │ │ │III. Angle of greatest stability │ 40° │ 21° │ │ IV. Greatest righting force in foot-tons │ 15,615 │ 7,100 │ │ V. Angle at which the righting force ceases │ 59° │ 54° │ │ VI. Reserve of dynamical stability at an angle│ 6,500 │ 410 │ │ of 14° in _dynamical_ foot-tons │ │ │ └───────────────────────────────────────────────┴──────────┴──────────┘

From No. V. in the above table we learn that if the _Captain_ had been heeled to 54°, the centre of gravity would have overtaken the centre of buoyancy—that is, the two would have been in one vertical line. Any further heeling would have brought the points into the position shown in Fig. 75, where it is obvious that the action of the forces is now to turn the vessel still more on its side, and the result is an upsetting couple instead of a righting couple.

These figures and considerations refer to the case of the vessel floating in smooth water, but the case of a vessel floating on a wave is not different in principle. The reader may picture to himself the diagrams inclined so that the water-line may represent a portion of the wave’s surface; then he must remember that the very action which heaves up the water in a sloping surface is so compounded with gravity, that the forces acting through G and B retain nearly the same position relatively to the surface as before.

No. VI. in the foregoing table requires some explanation. To heel a ship over to a certain angle a certain amount of _work_ must be done, and in the scientific sense _work_ is done only when something is moved through a space against a resistance. When the weight of a ton is raised 1 ft. high, one foot ton of work is said to be done; if 2 tons were raised 1 ft., or 1 ton were raised 2 ft., then two foot-tons of work would be done, and so on. The same would be the case if a pressure equal to those weights were applied so as to move a thing in any direction through the same distances. It should be carefully noticed that the foot-ton is quite a different unit in this case from what it is as the moment of a couple. If we heel a ship over by applying a pressure on the masts, it is plain that the pressure must act through a certain space, and the same heel could be caused either by means of a smaller pressure or a greater, according as we apply it higher up or lower down; but the space through which it must act would vary, so that the product of the pressure and space would, however, be always the same. No. VI. shows the amount of work that would have to be done in order completely to upset each of the vessels when already steadily heeled over to 14°. The amounts in the two cases are so different that we can easily understand how a squall which would not endanger the _Monarch_ might throw the _Captain_ over. A squall suddenly springing up would do more than heel a vessel over to the angle at which it is able to maintain it: it would swing it beyond that position by reason of the work done on the sails as they are moving over with the vessel, and the latter would come to a steady angle of heel only after a series of oscillations. Squalls, again, which, although suddenly springing up in this manner, could not heel the ship over beyond the angle where the stability vanishes, might yet do so if they were intermittent and should happen to coincide in time with the oscillations of the ship—just as a series of very small impulses, coinciding with the time of the vibrations of a heavy pendulum, may accumulate so as to increase the range of vibration to any extent. It is believed that in the case of the _Captain_ the pressure of the wind on the underside of the hurricane assisted in upsetting the vessel. This, however, could only have exerted a very small effect compared to that produced by the sails. The instability of the _Captain_ does not appear to have been discovered by such calculations as were made before the vessel went to sea. It was observed, however, that the ship when afloat was 1 ft. 6 in. deeper in the water than she should have been—in other words, the freeboard, or side of the ship out of the water, instead of being 8 ft. high as intended, was only 6 ft. 6 in., and such a difference would have a great effect on the stability.

FIG. 76.—_H.M.S. Glatton._
]

The turret system has been applied to other ships on quite a different plan. Of these the _Glatton_ is one of the most remarkable. Her appearance is very singular, and totally unlike that which we look for in a ship, as may be seen by an inspection of Fig. 76, page 162. The _Glatton_, which was launched in 1871, is of the _Monitor_ class, and was designed by Mr. E. J. Reed, who has sought to give the ship the most complete protection. With this view the hull is covered with iron plates below the water-line, and the deck also is cased with 3 in. iron plates, to resist shot or shell falling vertically. The base of the turret is shielded by a massive breastwork, which is a peculiarity of this ship. The large quantity of iron required for all these extra defences has, of course, the effect of increasing the immersion of the vessel, and therefore of diminishing her speed. The freeboard when the ship is in ordinary trim is only 3 ft. high, and means are provided for admitting water to the lowest compartment, so as to increase the immersion by 1 ft., thus reducing the freeboard to only 2 ft. when the vessel is in fighting trim, leaving only that small portion of the hull above water as a mark for the enemy. The water ballast can be pumped out when no longer needed. The _Glatton_ is 245 ft. long and 54 ft. broad, and she draws 19 ft. of water with the freeboard of 3 ft., displacing 4,865 tons of water, while, with the 2 ft. freeboard, the displacement is 5,179 tons. This ship cost £210,000. Mr. Reed wished to construct a vessel of much larger size on the same plan—a proposal to which, however, the Admiralty did not then consent. The _Glatton_ is, nevertheless, one of the most powerful ships of war ever built, and may be considered as an impregnable floating fortress. Above the water-line the hull is covered with armour plates 12 in. thick, supported by 20 in. of teak backing, and an inner layer of iron 1 in. thick. Below the water-line the iron is 8 in. thick, and the teak 10 in. The revolving turret carries two 25–ton guns, firing each a 600 lb. shot, and is covered by a massive plating of iron 14 in. in thickness. Besides this the base of the turret is protected by a breastwork rising 6 ft. above the hull. This breastwork is formed of plates 12 in. thick, fastened on 18 in. of teak. The turret rises 7 ft. above the breastwork, and therefore the latter in no way impedes the working of the guns. The _Glatton_ has a great advantage over all the other turret ships in having a perfectly unimpeded fore range for her guns, for there is no mast or other object to prevent the guns being fired directly over the bow. There are no sails, the mast being intended only for flying signals and hoisting up boats, &c. The hull is divided by vertical partitions into nine water-tight compartments, and also into three horizontal flats—the lowest being air-tight, and having arrangements for the admission and removal of water, as already mentioned. The stem of the ship is protruded forwards below the water for about 8 ft., thus forming a huge ram which would itself render the _Glatton_ a truly formidable antagonist at close quarters even if her guns were not used. The engines are capable of being worked up to 3,000 horse-power, giving the ship a speed of 9½ knots per hour, and means are provided for turning the turret by steam power. The turret can be rotated by manual labour, requiring about three minutes for its complete revolution, but by steam power the operation can be effected in half a minute. The commander communicates his orders from the pilot-house on the hurricane deck to the engine-room, steering-house, and turret, by means of speaking-tubes and electric telegraphs. The _Glatton_ was not designed to be ocean-going, but is intended for coast defence.

FIG. 77.—_H.M.S. Thunderer._
]

The British navy contains two powerful turret-ships constructed on the same general plan as the _Glatton_, but larger, and capable of steaming at a greater speed, and of carrying coal for a long voyage. These sister ships are named the _Devastation_, Fig. 69, and the _Thunderer_, Fig. 77. The _Thunderer_ has two turrets and a freeboard of 4 ft. 6 in. Space is provided for a store of 1,800 tons of coal, of which the _Glatton_ can carry only 500 tons. The vessel is fitted with twin screws, turned by two pairs of independent engines, capable of working up to 5,600 horse-power, and she can steam at the rate of 12 knots, or nearly 14 miles, an hour. With the large supply of coal she can carry, the _Thunderer_ could make a voyage of 3,000 miles without re-coaling. Though the freeboard of the heavily-plated hull is only 4 ft. 6 in., a lighter iron superstructure, indicated in the figure by the light shading, rises from the deck to the height of 7 ft., making the real freeboard nearly 12 ft. This gives the ship much greater stability, and prevents her from rolling heavily when at sea. The length is 285 ft. and the width 58 ft., and the draught 26 ft. The hull is double, the distance between the outer and inner skins of the bottom being 4 ft. 6 in. The framing is very strong and on the longitudinal principle, and the keel is formed of Bessemer steel. Each turret is 24 ft. 3 in. in internal diameter, and is built with five layers of teak and iron. Beginning at the inside, there is a lining of 2⅝ in. iron plates; then 6 in. of teak in iron frames, arranged horizontally; 6 in. of armour plates; 9 in. of teak, placed vertically; outside of all, 8 in. armour plates. Each turret carries two Fraser 35–ton guns, rifled muzzle-loaders. The turrets revolve by hand or by steam-power. There are no sails, and thus a clear range for the guns is afforded fore and aft. The bases of the turrets are protected by the armoured breastwork, of which a portion is seen in the figure in advance of the fore turret.

Another very powerful ship of war, which possesses some special features, is represented in the diagram on page 165, Fig. 78. This vessel, named the _König Wilhelm_, was built at Blackwall for the Prussian Government by the Thames Ironworks and Steam Shipbuilding Company, from designs by Mr. Reed. Her length is 365 ft., width 60 ft.; burthen, 6,000 tons; displacement, 8,500 tons. She is framed longitudinally, that is, girders pass from end to end, about 7 ft. apart, and the stem projects into a pointed ram. In this case also the hull is double; there is, in fact, one hull within another, with a space of 4½ ft. between them. The armour plates are 8 in. in thickness, with 10 in. of teak backing; but on the less important parts the thickness of the iron is reduced to 6 in., and in some places to 4 in. This ship has a broadside battery, and there are no turrets, but on the deck there are, fore and aft, two semicircular shields, formed of iron plates and teak, pierced with port-holes for cannon, and also with loop-holes for muskets. From these a fore-and-aft fire may be kept up. The ship is fully rigged, and has also steam engines of 7,000 horse-power, by Maudslay and Co. Her armament consists of four three-hundred-pounders, capable of delivering fore-and-aft as well as broadside fire, and twenty-three other guns of the same size between decks. These guns are all Krupp’s steel breech-loaders.

FIG. 78.—_The König Wilhelm._
]

FIG. 78_a_.—_The “Victoria” leaving Newcastle-on-Tyne._
]

The great contest of armour plates _versus_ guns has already been alluded to, and to the remarks then made it may be added that, while on the one hand, guns weighing 110 tons are mounted in turrets, ships are already designed with 18 in. and even 20 in. of steel armour plates. It would be very difficult to predict which side will sooner reach the limit beyond which increase of size and power cannot go. The gradual increase of thickness of plating, attended by increased weight of guns, projectiles, and charges of powder, may be illustrated by stating in a condensed form a few details of some ships, as regards the thickness of armour, and its resisting power, which is nearly in proportion to the square of its thickness; and also some particulars respecting the guns originally carried by those ships.

┌──────────────┬──────────┬──────────┬──────────┬──────────┬──────────┐ │ │_Warrior._│ _Her- │_Glatton._│ _Thun- │ _Vic- │ │ │ │ cules._ │ │ derer._ │ toria._ │ ├──────────────┼──────────┼──────────┼──────────┼──────────┼──────────┤ │Date when │ 1861 │ 1868 │ 1872 │ 1877 │ 1889 │ │ completed │ │ │ │ │ │ │Thickness of │ 4½ │ 9 │ 12 │ 14 │ 18 │ │ iron plating│ │ │ │ │ │ │ in inches │ │ │ │ │ │ │Relative │ 20 │ 81 │ 144 │ 196 │ 324 │ │ resisting │ │ │ │ │ │ │ power of │ │ │ │ │ │ │ plating │ │ │ │ │ │ │Guns carried │Cast iron,│ Wrought │ Wrought │ Wrought │ Steel, │ │ │ smooth │ iron, │ iron, │ iron, │ Rifled │ │ │ bore │ rifled │ rifled │ rifled │ │ │Weight of guns│ 4¾ │ 18 │ 25 │ 35 │ 111 │ │ in tons │ │ │ │ │ │ │Charge of │ 16 │ 60 │ 70 │ 120 │ 960 │ │ powder in │ │ │ │ │ │ │ lbs. │ │ │ │ │ │ │Weight of │ 68 │ 400 │ 600 │ 700 │ 1,800 │ │ projectiles │ │ │ │ │ │ │ in lbs. │ │ │ │ │ │ │Destructive │ 452 │ 3,863 │ 5,165 │ 8,404 │ 56,000 │ │ power of │ │ │ │ │ │ │ projectiles │ │ │ │ │ │ │ in foot-tons│ │ │ │ │ │ └──────────────┴──────────┴──────────┴──────────┴──────────┴──────────┘

One of the latest additions out of the thirty or forty armoured ships that have been added to the British Navy since the preceding pages were written is included in the above table for the sake of comparison. Our ironclad fleet now includes vessels protected and armed in many different ways. Some have the protective armour extended continuously along the water-line, others have it for only a greater or less part of their length. The armaments are also very diverse as to the size of the guns and the way in which they are mounted. A few carry one or two of the huge 110–ton gun mounted in massive revolving turrets; others have their guns in central batteries, or in _barbettes_, and others again are arranged as broadside ships; while these plans are also variously combined so as to form a great number of different types. In the ships built within the last 15 years, steel has been almost invariably used instead of iron for the armour-plating. A great increase of speed has been obtained in late years. The largest British armoured ships yet launched have displacements between 10,000 and 12,000 tons, but another class of first-rate line-of-battle ships of still greater size is in process of construction, and of these it is estimated that four will be completed in 1893. They are all of the same design and armament, and will have a displacement of 14,150 tons, a length of 380 feet, and a breadth of 75 feet. The armour plates at the sides will be 18 inches thick. Each ship will carry four 67–ton breech loading rifled guns, ten 6–inch quick firing guns, and 18 other smaller guns, also quick firing. These vessels are expected to realize a speed of about 20 miles per hour; but this is somewhat less than a few of the heavy ironclads now afloat have given by actual trial, a rate equal to 21⅓ miles an hour having been attained by some. Several of our rapid unarmoured cruisers are able to steam at 25 miles an hour.

Before the close of 1894, the British navy possessed no fewer than eight of the largest armoured line of battle-ships mentioned in the foregoing paragraph, each being of 14,150 tons displacement, and having engines of 13,000 horse-power. At the same period there were in course of construction four ships surpassing even these in tonnage, though of somewhat less engine-power. Two were building at Portsmouth, to be called the _Majestic_ and the _Royal George_, whilst the _Jupiter_ was in progress at Glasgow and the _Mars_ at Birkenhead. All these are very heavily armoured vessels, each displacing 14,900 tons, provided with engines of 12,000 horse-power, and a very effective armament of guns. Among the powerful ships of the navy may now also be noted the _Blake_, the _Blenheim_, which, although the displacement is only 500 tons greater than that of _König Wilhelm_, have engines of nearly three times the power, namely, of 20,000 horse-power. Of large armoured ships, namely, those of _9,000 tons and upwards_, Great Britain now has afloat at least fifty; and the advance that has taken place in the size and power of war-ships during the last twenty years may be inferred by reference to the foregoing paragraphs giving the dimensions, &c., of the _Glatton_ and the _Thunderer_, which paragraphs are, for the sake of comparison, allowed to appear as they did in the first edition (1876) of this book. Besides these very large armoured vessels, of which the smallest is nearly twice as big as the largest of twenty-five years ago, the British navy comprises ships of every size and for every purpose, and so many of them that their names and classifications would occupy many pages.

Two recent additions representing new type of ships claim notice before this article is concluded. These are first the _Terrible_, with a sister ship the _Powerful_. The former, of which a representation[3] is given in Plate V., is pronounced, for its size, armour, armament, and speed taken together, to be the most powerful cruiser in the world. The length is 538 ft., breadth 71 ft., depth 43 ft., and the displacement is 14,250 tons. A special object in the design of this vessel was high speed, and she is provided with twin-screws and two engines, the combined effort of which is equal to 25,000 horse-power. There are forty-eight boilers and four funnels, the ship being capable of carrying 3,000 tons of coal. The vessel is built on the lines of the great Atlantic steamers, and the engines, guns, and magazines are protected by a thick curved armour deck. The vessel has a speed of 22 knots, or 25⅓ miles per hour. Her armament consists of two 22–ton guns, twelve 6–in. quick-firing, and many other smaller machine guns, and she carries besides four submerged torpedo tubes. A second ship to be noted is amongst those designed mainly to exceed all other craft in speed, and ranging in tonnage from 3,800 to 4,500. The _Janus_, a torpedo-boat destroyer of this class, was found, at a recent trial over a measured mile, to attain the then unexampled speed of 28 knots, or 32¼ miles per hour. But even this has been beaten by a new torpedo-boat destroyer, built by Messrs. Yarrow at Poplar for the Russian Government, and launched in August, 1895. This vessel, within a few hours after leaving the stocks, cut through the water at the rate of 30·285 knots, or nearly 35 miles, per hour.

Footnote 3:

From _Graphic_, 1st June, 1895.

A sad fate befell the _Victoria_, which was one of the heaviest armed of British ships (_vide_ page 129), when taking part in some naval manœuvres off Tripoli, on the Syrian coast, where she was the flag-ship of Admiral Tryon, commander-in-chief of the squadron. On the 22nd June, 1893, in consequence of an inconsiderate order given by the admiral himself, the _Victoria_ was struck by the formidable ram of the _Camperdown_ (10,600), and in fifteen minutes turned over and sank in sight of the whole fleet, carrying down with her the admiral, 30 officers, and 320 men, out of a crew of 600. [1895.]

FIG. 78_b_.—_Firing at a floating battery._
]

PLATE XI. H.M.S. “TERRIBLE.”
]

FIG. 79.—_Krupp’s Works, at Essen, Prussia_.
]

FIRE-ARMS.

The invention of gunpowder—or rather its use in war—appears at first sight a device little calculated to promote the general progress of mankind. But it has been pointed out by some historians that the introduction of gunpowder into Europe brought about the downfall of the feudal system with its attendant evils. In those days every man was practically a soldier: the bow or the sword he inherited from his father made him ready for the fray. But when cannons, muskets, and mines began to be used, the art of war became more difficult. The simple possession of arms did not render men soldiers, but a long special training was required. The greater cost of the new arms also contributed to change the arrangements of society. Standing armies were established, and war became the calling of only a small part of the inhabitants of a country, while the majority were left free to devote themselves to civil employments. Then the useful arts of life received more attention, inventions were multiplied, commerce began to be considered as honourable an avocation as war, letters were cultivated, and other foundations laid for modern science. If such have really been the indirect results of the invention of gunpowder, we shall hardly share the regret of the fine gentleman in “Henry IV.”:

“That it was great pity, so it was,
That villanous saltpetre should be digged
Out of the bowels of the harmless earth,
Which many a good tall fellow had destroyed
So cowardly.”

We often hear people regretting that so much attention and ingenuity as are shown by the weapons of the present day should have been expended upon implements of destruction. It would not perhaps be difficult to show that if we must have wars, the more effective the implements of destruction, the shorter and more decisive will be the struggles, and the less the total loss of life, though occurring in a shorter time. Then, again, the exasperated and savage feelings evoked by the hand-to-hand fighting under the old system have less opportunity for their exercise in modern warfare, which more resembles a game of skill. But the wise and the good have in all ages looked forward to a time when sword and spear shall be everywhere finally superseded by the ploughshare and the reaping-hook, and the whole human race shall dwell together in amity. Until that happy time arrives—

“Till the war-drum throbs no longer, and the battle flags are furl’d
In the Parliament of man, the Federation of the world—
When the common sense of most shall hold a fretful realm in awe,
And the kindly earth shall slumber, lapt in universal law,”—

we may consider that the more costly and ingenious and complicated the implements of war become, the more certain will be the extension and the permanence of civilization. The great cost of such appliances as those we are about to describe, the ingenuity needed for their contrivance, the elaborate machinery required for their production, and the skill implied in their use, are such that these weapons can never be the arms of other than wealthy and intelligent nations. We know that in ancient times opulent and civilized communities could hardly defend themselves against poor and barbarous races. But the world cannot again witness such a spectacle as Rome presented when the savage hordes of Alaric swarmed through her gates, and the mighty civilization of centuries fell under the assaults of the northern barbarians. In our day it is the poor and barbarous tribes who are everywhere at the mercy of the wealthy and cultivated nations. The present age has been so remarkably fertile in warlike inventions, that it may truthfully be said that the progress made in fire-arms and war-ships within the second half of the nineteenth century surpasses everything that had been previously accomplished from the time gunpowder came into use. Englishmen have good reason to be proud of the position taken by their country, and may feel assured that her armaments will enable her to hold her own among the most advanced nations of the world.

The subject of fire-arms embraces a very wide ground, as will appear if we consider the many different forms in which these weapons are constructed in order best to serve particular purposes. Pertaining to this subject, attention must also be directed to the modern projectiles and to the newer explosives that have largely taken the place of ordinary gunpowder. The shot gun, fowling-piece, and sporting rifle properly come under the head of fire-arms, and in the march of improvement these forms have most commonly been in advance of military muskets and rifles, the ingenuity bestowed on all their details being worthy of admiration. Nevertheless it is to the implements of war that general interest attaches; for on them depends so much the fate of battles and the destiny of nations, that whenever any country is engaged in war the question of arms becomes one of surpassing importance, enlisting the patriotic instincts of every citizen. Hence in the following pages our space will be devoted mainly to weapons of war, and more particularly to those that have been adopted by our own country.

Everyone of course is aware that guns, cannon, and gunpowder are by no means inventions of the nineteenth century; but there are fewer acquainted with the fact that rifling, breech-loading, machine guns, and revolvers were all invented and tried hundreds of years before. The devices by which some of these ideas were sought to be realised in past ages appear to us in some instances very primitive, not to say childish, when compared with modern work: but it must be remembered that nearly all the appliances required for producing such weapons had themselves to wait for their invention until the nineteenth century; such, for instance, as the steam-hammer, powerful and accurate tools, refined measuring implements, material entirely reliable such as the new steel, and also scientific investigations of all the conditions involved. The military fire-arms are of so many different forms and patterns that we can deal here with but a selection from the various services. If a rough classification had to be made, the most obvious distinction would be between the weapons the soldier carries in his hands (small-arms) and those which are mounted on some kind of carriage and discharge projectiles of much greater weight (ordnance). Ordnance again includes guns mounted on forts, carried in ships, or taken with an army into the field, in each case coming into action under different conditions. Partaking somewhat of the nature of both field-guns and of small-arms are the machine guns, of which the French mitrailleur was the first example, afterwards developing into much more effective weapons in the hands of Gatling, Gardner, Nordenfelt, Maxim, and Hotchkiss.

As much will have to be said about _rifling_ the bores of muskets and cannon, we may here explain the nature and object of this device. The projectiles used in all guns down to comparatively recent times were almost invariably of spherical form, and could indeed scarcely be otherwise with smooth-bore weapons. As the diameter of the shot would necessarily be something less than that of the bore of the barrel, a considerable loss of power would result from the escape of the powder gases between the shot and the barrel, which escape is known as _windage_. Another disadvantage of the spherical projectile is that for the same weight of metal the air offers a greater resistance to its passage, and consequently checks its speed more quickly than that of any other circular form; for the air resistance is proportional to the square of the diameter, and therefore if we take a ball of 1 in. diameter and a cylinder of 1 in. in length, each having the same weight of metal, the diameter of the cylindrical shot will be a little more than four-fifths of an inch, and the air resistance to the ball will be exactly half as much again as to the cylinder, that is, in the proportion of 3 to 2. Again, the passage of the spherical shot within the barrel of the gun will not be in a straight line, but in a series of rebounds from side to side, and its direction on leaving the muzzle will depend upon which part of the bore it just before impinges on, as from that it will also take a rotatory “twist” that will in part determine its path through the air.

Now if an elongated projectile were fired from a smooth-bore gun, its course through the air would be erratic to a degree impossible to the spherical shot, for it would turn end over end with deviations that would make aiming impracticable. But if the elongated projectile is made to spin rapidly enough about its longitudinal axis, it flies through the air quite steadily, the axis of rotation remaining parallel to that of the gun throughout the whole flight. The steadiness due to rapid rotation has familiar examples in spinning tops, in gyroscopic tops, in the way arrows are feathered so that the air may cause them to revolve axially, and so on. The axial rotation of the projectile is effected by ploughing out in the cylindrical barrel of the gun a number of spiral or twisting grooves, which the projectile is compelled to follow as it travels along the barrel, either by means of corresponding protuberances formed upon its surface in the first instance, as in Jacob’s bullets, or by studs let into it, as in the studded shots and shells for ordnance which constituted at one time the regulation plan adopted by the British Government; or otherwise by making the force of the explosion expand some portion of the projectile in such a manner that this portion shall completely fill up the grooves, thus preventing windage, and causing the projectile to follow the twist of the grooves. This is the more general method, especially since the adoption of breech-loading. The Lancaster rifling, and that advocated by Whitworth, are the same in principle, but differ in appearance, from the section of the barrel being made in the one case oval, in the other hexagonal or polygonal, but with the twist necessary to produce rotation.

Incident to the discharge of all fire-arms, great and small, is a phenomenon of which we have to speak, because it is one which in the mounting of heavy ordnance especially has to be taken into account. And as it also illustrates in a very direct way one of the most general laws of nature, while people often have very vague and erroneous ideas of its cause and operation, it deserves the reader’s attention. In gunnery it is called the _recoil_, and is familiar to anyone who has ever fired a pistol, fowling-piece, or rifle, in the kick backwards felt at the moment of the discharge. This law is in operation whenever the condition of a body in respect to its rest or motion is changing. That is, whenever a body at rest has motion given to, or if when already moving it is made to go faster or slower, or to stop, or when the direction of the motion is changed from that in a straight line. Now although these changes or actions are frequently occurring before our eyes, the operation in them of Newton’s third law of motion does not generally present itself to common observation. This third law was stated by Sir Isaac Newton thus:—“To every action there is always an opposite and equal reaction.” Now the expanding gases due to the gunpowder explosion press the bullet forwards and the barrel (with its attachments) backwards, with the same pressure in both cases, but at the end of the bullet’s passage along the bore the same velocity is not imparted to the two bodies, because the same pressure acting for the same time on bodies of unequal _mass_ always produces velocities that are inversely proportional to the _masses_. The reader should try to acquire this conception of _mass_, remarking that it is a something quite distinct from that of _weight_. A given lump of metal, for instance, would have exactly the same _mass_ in any part of the universe, whereas its weight would depend upon its position; as, for instance, at the distance from the earth of the moon’s orbit, it would _weigh_ only as 1/3600th part of its weight at the earth’s surface, and if it could be carried to the very centre of the earth it would there have no weight at all. Though the lump of metal will have different weights at different parts of the earth’s surface, it has been found (by experiment) that the weights of bodies at any one place are proportional to their masses. Therefore the same numbers that express the weights of bodies might also express their masses; but for certain good reasons these quantities are referred to different units. In England a piece of metal weighing 32 lbs. under standard conditions is said to have mass = 1; and so on. As with the _same pressure acting for the same time_, the velocities imparted are inversely proportional to the masses, it follows that the number expressing the velocity multiplied by that representing the mass in each such case of action and reaction will give the same product, or in other words the _amount of motion_ (momentum) will be the same. This is what Newton meant by saying the reaction is _equal_ to the action. We may now by way of illustration calculate the velocity of recoil of a rifle under conditions similar to those that might occur in practice. Let us suppose that the rifle, including the stock and all attachments, weighs 10 lbs., and that from it is fired a bullet weighing one-sixteenth of a pound, with a velocity at the muzzle of 1,200 ft. per second. To obtain the amount of motion or the momentum, we should here multiply the number expressing the _mass_ of the bullet by 1,200, but for our present purpose the weight numbers may be used for the sake of simplicity; therefore 1/16 x 1,200 = 75 will represent (proportionately) the forward momentum of the bullet, and according to Newton’s law the backward momentum of the rifle will be, on the same scale, 75 also. We must therefore find the number which multiplied by 10 will give 75, and this obviously is 7·5. That is as much as to say that at the instant the bullet is leaving the muzzle, the rifle itself, _if free to move_, would be moving backward at the speed of 7½ ft. per second. Observe that this result would be the same if the rifle were fired where weight is non-existent; nor is the recoil due, as sometimes is erroneously supposed, to the resistance of the air to the passage of the bullet along the barrel, for even if the air were abolished, the recoil, so far as due to the masses and velocities, would remain the same, as indeed may be seen from the fact of our calculation taking no account of the bore of the rifle or of the shape of the bullet, circumstances of the utmost importance where atmospheric resistance is concerned.

The foregoing calculation however involves an assumption not in exact conformity with actual conditions, by taking for granted that the _centre of gravity_ of the rifle is in the line of the axis of the barrel, while in fact this centre is almost always lower, and therefore the kick of the recoil acts in part as a turning-over push, tending to tilt up the muzzle of the gun, and for that reason the firer must hold the weapon very firmly or he will miss his aim. When such a rifle as we have supposed is fired, say from the shoulder, it would follow from the above calculation that the backward kick of the recoil is equivalent to a blow from a 10–lb. weight moving at the speed of 7½ ft. per second. This would certainly be a very uncomfortable experience, but the backward momentum must be met somehow. We have supposed that the gun is free to move, but we know the firer presses it firmly against the muscles of his shoulder, and the stock of the gun is spread out and provided with a smooth hollow heel plate, so that any pressure from it is felt as little as possible, especially as the muscle against which it is applied acts as an elastic pad. With the rifle thus firmly held we may regard the marksman and his rifle as forming only _one mass_, and the centre of gravity of this being now much below the axis of the barrel, the effect of the recoil tends to overthrow the man backwards; but he learns to resist this by standing firmly, so that the elasticity of his whole frame comes into play; and besides this, the mass factor of the momentum being now so large, the velocity factor becomes comparatively insignificant.

Although the momenta of gun and projectile are, according to Newton’s law, _equal_ and opposite, the case is very different with regard to their _energies_, or powers of doing work, for the measure of these is jointly mass and _the square of the velocity_. The _energy_ (_vis viva_) of a body of weight in pounds = W, moving with the velocity of v feet per second is always Wv^2/64·4, that is, it will do this number of foot-lbs. units of work before it comes to rest. It would require too much space to demonstrate and fully explain here what this means, but the reader may refer to our index under the entries “Energy” and “Work,” or to any modern elementary treatise on dynamics. If the calculation be made of the energies of the ball and of the rifle due to our calculated velocities of recoil, it will be found that that of the ball is 160 times greater than that of the other, and the ball possesses this energy in a much smaller compass.

FIG. 80.—_Trajectory of a Projectile._
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The course or track of a projectile through the air after it leaves the gun is called the _trajectory_, and this has been studied both experimentally and theoretically, with interesting results. Assuming that the shot passed through empty space, or that the air offered no resistance to its passage, it would be very easy to trace the path of a projectile. Let us suppose that Fig. 80 represents a gun elevated at a high angle. The moment the projectile leaves the muzzle, gravity begins to act upon it, causing it to move vertically downwards with ever-increasing velocity until it finally reaches the ground; the onward uniform movement parallel to the axis of the piece being continued all the time. We could find the position of the projectile at the end of successive equal periods of time by drawing a straight line AC, a prolongation of the axis of the piece, or a line of the same inclination; on this we mark off equal distances representing by scale the velocity of the projectile per second, the points B, C, D, E being the positions the projectile would be in at the end of each successive second if gravity did not act. In order to bring the diagram within moderate compass, we suppose the projectile to have only the small velocity of 115 ft. per second. At the end of the first second it would be at B, but now suppose that gravity is allowed to act for one second, it would at the end of that time have fallen 16 ft. vertically below B and have arrived at _b_. Similarly we may set off by scale on verticals through C, D, and E distances representing 64 ft., 144 ft., and 256 ft. respectively. Because, for instance, the ball, without gravity acting, would at the end of 3 seconds be at D, where we may suppose its course arrested and gravity then allowed to act for 3 seconds to pull the ball down from its position of rest at D; at the end of this period, gravity alone acting, its position would be 144 ft. vertically below D, because gravity pulls a body that distance in 3 seconds, and the actual position 3 seconds after the ball had left the muzzle would be at _d_, after it had described the curved path A, _b_, _c_, _d_. Supposing _d_ to be the highest point of the trajectory, another 3 seconds would bring the ball along a downward curve, and at the end of 6 seconds from the discharge it would be at a point on the same level as A. Now the complete curve would be symmetrical on each side of a vertical line through its highest point, and it would be in fact a regular _parabola_ with its vertex at _d_.