Warships and their story

by R. A. Fletcher

CHAPTER IX

GUNS, PROJECTILES AND ARMOUR

The introduction of direct shell fire at Sebastopol was a most important advance in the science of attack, and was followed soon afterwards by the adoption of elongated instead of circular projectiles, the French leading the way. Both for solid shot and explosive projectiles, it became necessary to increase the range and accuracy. To do this the windage had to be reduced as much as possible and the barrels of the guns were rifled in order to give the projectile a certain amount of twist on its axis.

Rifled breech-loading guns were proposed by Major Cavalli, of the Sardinian artillery, and by Baron Warendorff, of Sweden, and experiments were made with the weapons in this and other countries. A great deal of difficulty was found in adopting rifling for heavy guns, owing to the much greater strain imposed upon the metal, and the difficulties were still further increased when it became necessary that ordnance should be produced of very large calibre and able to throw heavy projectiles with high velocities. One way in which it was sought to get over the difficulty was by reducing the charge of powder considerably, and as the form of the newer projectiles was different from that of the old spherical projectiles, and the windage was as far as possible eliminated, it was found that this plan gave the desired result. Wrought iron and steel replaced cast-iron and bronze, though a few cast-iron rifled guns were strengthened with steel hoops. Wrought iron was adopted for gun carriages, and steel or chilled iron for armour-piercing projectiles.

Sir Henry Bessemer manufactured the first gun that was ever made of malleable iron without a weld or joint, and though he showed that guns could be made of steel, the Admiralty, with its then fondness for the things of the days that were, decided to continue making its guns of iron. But when the bore of the iron gun showed cracks, the Admiralty decided on the insertion of a steel tube, and tied it with a piece of iron.

“Why not with a piece of steel?” Sir Henry Bessemer asked, in 1881, many years later. “Why not a cylinder made of steel in preference to that iron coil? For the making of steel cylinders was then an accomplished fact, but the making of those iron coils was not an accomplished fact. The iron coil system has been thoroughly shown up, but at an enormous expense to this country. The incident was the turning-point which made us have iron guns, while every other country in the world has got steel guns.” But the next year the Government decided that the Navy’s guns should be constructed entirely of steel.

At the International Exhibition of 1862, a spherical steel cannon-ball was exhibited, and in January, 1864, some particulars were published of trials of projectiles of this class fired from a smooth-bore against armour-plate 5½ inches in thickness. This moved Sir Henry to remark that an expenditure of £50 three years earlier would have given as full a proof of the efficiency of these projectiles.

“Meanwhile how many hundred thousands pounds have been expended in building iron-plated ships, which these long-neglected steel projectiles will riddle as easily as the cast-iron shot found its way through the wooden walls of our old men-of-war!... It is not less remarkable that while our firm at Sheffield have manufactured some hundred and fifty pieces of Bessemer steel ordnance for foreign service, guns of this material are still untried by our government, although it is well known that the strength of this metal is double that of ordinary iron, while such is the facility of production that a solid steel gun block of twenty tons in weight can be produced from cast fluid in the short space of twenty minutes, the homogeneous mass being free from weld or joint.

“Our armour-plate system has certainly received a severe shock, and it behoves us now to see how far it is possible to increase the resisting power of ships so as to keep pace with the advances made by steel shot.... The fine ship Minotaur ... was all that excellent workmanship and the best iron could make her, but still she was only iron. It has been stated that the hull of the vessel weighs 6,000 tons, and her 4½-inch armour 1,850 tons. Now, had the hull of this vessel been built of a material possessing double the strength of ordinary iron her weight might have been reduced to 3,000 tons; but suppose that, while we admit a double strength of material, we only reduce the weight by one-third, this would give 4,000 tons of steel for the hull. Now, with this reduction in the weight of the hull, we may employ 9-inch armour-plates in lieu of the 4½-inch armour-plates now employed. It must be borne in mind that the resistance offered by the armour-plate is equal to the square of its thickness; hence a vessel constructed in the manner proposed would bear a blow of four times the force that the present structure is calculated to withstand. Thousands of Bessemer steel projectiles are now being made for Russia.... Have we a single ship afloat that can keep out these simple round steel shots fired from a common smooth-bore gun, if ever directed against us?”

12½-PR. Q.F. 50-CALIBRE GUN AND MOUNTING.

4-INCH B.L. 40-CALIBRE GUN AND MOUNTING FOR TORPEDO BOAT
DESTROYERS.

Photographs supplied by the Coventry Ordnance Works, Ltd.

After a remarkable series of experiments, Sir Joseph Whitworth produced a number of rifled guns of great power and precision. In 1863 they proved their worth in the Civil War in America, and in 1864 a series of competitive experiments was conducted by the British Government at Shoeburyness between the Armstrong and Whitworth guns. The committee of artillerists reported its inability to decide which was the better weapon, and the Whitworth gun was not then adopted by the Government, though foreign nations bought them largely. Four years later a Whitworth gun was produced which threw a 250-lb. projectile 11,243 yards, a range never before attained, and a 310-lb. projectile, 11,127 yards. Sir J. Whitworth also attempted to prove that a flat-headed projectile will penetrate armour-plates even when striking obliquely.

Like all inventors of war material of increased efficiency, he believed that the more destructive the weapons and explosives the more improbable would war become, until it should be rendered impossible.

“Were it not that the increased destructiveness of war must tend to shorten its duration and diminish its frequency—thus saving human life—the invention of my projectiles could hardly be justified; but believing in the really pacific influence of the most powerful means of defence, these long projectiles I call the anti-war shell.” But Sir Joseph Whitworth was disappointed, and the millennium has not dawned yet.

His own summary of what he accomplished, however, shows how one step after another has been taken in the production of weapon after weapon. The progress has been maintained by one inventor and scientist after another, until the remarkable guns with their 25-miles range which now are carried have been made possible.

“In 1857 I proved for the first time that a ship could be penetrated below the water-line by a flat-headed rifled projectile.

“In 1860 I penetrated for the first time a 4½-inch armour-plate with an 80-lb. flat-headed solid steel projectile. In 1862 I penetrated for the first time a 4-inch armour-plate with a 70-lb. flat-headed steel shell, which exploded in an oak box supporting the plate. In 1870 I penetrated with a 9-inch bore gun three 5-inch armour-plates inter-laminated with two 5-inch layers of concrete. In 1872, with my 9-pounder breech-loading gun and a flat-headed steel projectile, I penetrated a 3-inch armour-plate at an angle of 45 degrees. All these performances were the first of their kind and were made, with one exception, with flat-headed projectiles, which alone are capable of penetrating armour-plates when impinging obliquely, and which alone can penetrate a ship below the water-line.”

The Brazilian Government began a series of experiments in 1871 which convinced them that better guns were produced in this country than on the Continent. The Bessemer steel process was improved by Sir Joseph Whitworth for gun-making, and having adopted breech-loading guns, he obtained results superior to those obtainable with any form of muzzle-loading weapon. The Brazilian Government gave permission for him to offer to lend to the British Admiralty a 7-inch breech-loading steel gun he had made for the former, and a 35-ton muzzle-loading gun, in order that comparative tests might be made, but the British Government declined; it had no love for breech-loaders.

Having produced a type of gun capable, as he believed, of penetrating any armour then in existence, Sir Joseph Whitworth set about producing an armour-plate which should be able to beat the gun. Using his compressed steel, he invented what he called “impregnable armour-plating,” built in hexagonal sections, each of which was constructed of a series of concentric rings arranged round a central circular disc, this method preventing a crack caused by the impact of a projectile from passing beyond the ring in which it occurred. A Palliser shell of 259 lb. fired from a 9-inch gun with a charge of 50 lb. of pebble powder, which would have smashed an ordinary 12-inch iron armour-plate, was itself smashed against this new armour, and the target itself was forced 18 inches back into the sand and was only slightly dented.

A great deal of reliance was placed in America on the gun invented by Mr. Rodman, after whom it was named. Several of the American monitors were armed with these weapons. One, bought by the British Government and tested at Shoeburyness, weighed 19 tons and had a smooth bore 15 inches in diameter, and fired a round shot of 453 lb. with a charge of 100 lb. of American powder. It pierced the 8-inch plates of the Warrior type of target, but as in other experiments it was less successful, the Americans claimed that it was used in such a way as not to show its full capabilities. Even if it had been, it could only have had a very short career, as the breech-loading gun was steadily making its way in foreign navies, and any form of smooth-bore muzzle-loader, whether American or English, would have proved singularly ineffective against ships carrying rifled breech-loaders. The Mackay gun, an English invention doomed to early supersession, was an attempt to combine the simplicity of the smooth-bore with the penetrating force of the rifled gun, and in experiments made with this weapon on the Agincourt target, in 1867, the gun fully demonstrated its usefulness.

HEAVY GUN UNMOUNTED.

6-INCH B.L. 50-CALIBRE GUN COMPLETED AND WITH MOUNTING.

Photographs supplied by the Coventry Ordnance Works, Ltd.

No satisfactory results either with rifling or with the hexagonal bore could be obtained, and as guns became more powerful it was found that the only way of utilising them with the best results was by loading them at the breech instead of at the muzzle. Obviously, a heavy explosive shell could not be rammed down a big muzzle-loader. The old 32-pounder had a muzzle velocity of 1,600 feet per second, and the 40-pounder rifled breech-loader which took its place was of only 1,200 foot seconds, and the muzzle energy was 570 and 400 foot tons respectively. Various methods were employed and were not by any means satisfactory, but when slower burning powders were introduced, the strain upon the gun was less sudden and more cumulative, so that the pressure upon the projectile was exerted to the full as long as it was within the gun and it was then expelled at the muzzle with the greatest force obtainable. A great advance in naval gunnery was made with the appearance of the Armstrong breech-loader. The first breech-loader from this famous firm was a tube gun which was formed to admit of a breech block being dropped in to close the bore and a screw attachment held it fast. From about 1860 the principal guns in use in the Navy of the Armstrong screw type were the 9-pounder weighing 6 cwt., the 12-pounder weighing 8 cwt., the 20-pounder of 16 cwt., the 40-pounder of 35 cwt., and the 7-inch gun, 99½ cwt. The last-named was of 7.2 inches diameter, and fired projectiles weighing 109 lb. All these guns were on the polygroove system. About this time iron or steel gun carriages were introduced for use on shipboard. The Admiralty, for some reason best known to themselves, fancied muzzle-loaders, and obstinately remained faithful to them long after all other naval powers had discarded them as cumbersome and comparatively useless compared with the newer types of breech-loading guns. The newer muzzle-loaders, however, were improvements on the old smooth-bores, and were built on what is known as the Fraser system, and they were far larger than any which had been constructed before.

The inner barrels of the Armstrong 12-inch, 9-inch, and 7-inch muzzle-loading guns were of tempered steel, with solid ends; these were strengthened with wrought-iron coils shrunk on; the trunnion ring, breech-piece and cascable, which was screwed into the latter, were solid wrought-iron forgings. The different parts were hooked together with shoulders and corresponding recesses, to prevent their separation.

The muzzle-loader of 64 lb. on Fraser’s cheap construction plan consisted simply of a coiled iron tube, having the muzzle part double, but with a triple coil over the breech.

The Armstrong big muzzle-loading guns were formed with the Woolwich system of rifling or grooving, the projectiles being fitted with studs to correspond to the grooves. The muzzle-loading guns varied from the 7-inch 7-ton gun to the 16-inch 80-ton gun. The 8-inch was 118 inches in length, the 9-inch 125 inches, and so on, up to the 16-inch gun, which was 288 inches in length; the last-named took a charge of 450 lb., and fired a projectile weighing 1,684 lb. with a muzzle velocity of 1,590 foot seconds and a muzzle energy of 29,530 foot tons, capable of penetrating at the muzzle between 24 and 25 inches of wrought iron.

By 1877 the initial velocity of rifled projectiles had been increased from 1,600 to 2,100 foot seconds, and the energies by nearly 75 per cent., so that a further reconstruction of artillery became compulsory. It was not until after 1881 that the Admiralty definitely adopted heavy breech-loading guns for its armed cruisers. Even as late as 1885 the squadron sent to sea when it was feared that trouble with Russia was brewing, included thirteen battleships, not one of which had a breech-loading gun of more than 6 inches diameter. As a contrast to this, all the heavy guns of the Russian ships were breech-loaders. What would have happened to the English ships had hostilities occurred, and had the Russian gunners been able to use their weapons properly, is best left to conjecture, but it might have proved a sorry day in the naval history of England. Even by 1894 muzzle-loaders were still in use in the Navy.

The Woolwich Armstrong breech-loading guns varied from 12-pounders of 3 inches to the 16.25-inch 111-ton gun, the length of which was equal to 30 calibres. The last-named gun took a charge of 960 lb. of powder, and fired a projectile weighing 1,800 lb. with a muzzle velocity of 2,087 foot seconds, and a muzzle energy of 54,390 foot tons, calculated to penetrate over 36 inches of wrought iron at the muzzle. Gunpowder not being powerful enough for these great weapons, other explosives were introduced, which had, among other advantages, that of being much more powerful. The principal of these explosives at present in use is cordite.

In the early ’sixties the guns chiefly in use on this side of the Atlantic were the 9-inch gun, weighing 12 tons, and discharging a 250-lb. shot with 43 lb. of powder, the initial velocity being 1,730 feet per second. The largest gun was the 23½ tons, with a 12-inch diameter, its shot weighing 600 lb. and the charge of powder 70 lb., and the muzzle velocity being 1,240 feet per second. The larger guns could not be worked without considerable improvements being made in the ships themselves. Greater height had to be given between the decks, and the distances between the guns had also to be increased, there being 25 feet between the centre lines of the ports for the 12-ton guns, while the 23-ton guns required about 30 feet between the ports and between 8 and 9 feet between the deck and the underside of the beams supporting the deck above. To keep the portholes as small as possible an arrangement was made whereby the gun should be pivoted near the muzzle.

The later developments in naval artillery began with the 12-inch 46-ton wire gun, which was the chief weapon of the battleships between 1894 and 1897. This gun was 37 feet 1 inch in length, or 35.43 calibres, and threw an armour-piercing shell of 850 lb. with a charge of 167½ lb. of cordite. It had a muzzle penetration of 36.8 inches of wrought iron, and was in every respect as powerful as the 13½-inch 67-ton gun, which it replaced. During 1898, the 12-inch wire gun, weighing about 50 tons, was introduced.

The adoption of breech-loading made possible a very rapid rate of firing, even with the heaviest guns. In 1881, the Government, in reply to an invitation it issued for guns to meet certain requirements, received a number of replies from gun-making firms, as did also the French Government at about the same time in reply to a similar invitation. These guns, which became known as quick-firing or rapid-firing guns, were comparatively small weapons, and the Armstrong Company at Elswick, having improved upon them with quick-firers of 4.7 inches and 6 inches calibre, they were adopted throughout the Navy as the secondary armament. Their superiority over those they displaced was such that a battery’s firing power was increased sixfold. An important trial took place on board the Hardy in 1887, when a 4.7 gun was mounted on a centre pivot recoil mounting, the whole weighing 4 tons 12 cwt.; this gun fired ten rounds in less than 48 seconds. Compare this with the firing of the ordinary 5-inch breech-loading gun on the gunboat Mastiff, when ten rounds took 6 minutes 16 seconds.

In rifling some of the guns an increasing twist was given, while in others the twist was uniform throughout the bore. The object of the increasing twist was to lessen the strain upon the gun, as the rotary motion was not started when the projectile was first put into motion, but developed as it moved down the bore. The projectiles were provided with studs which fitted into the grooves. The breech-loading guns on the polygonal system of rifling fired projectiles which were coated with lead fixed on with zinc, so that the bore of the gun was not injured by the rush of gas past the projectile as was the case in the rifled guns in which there was windage. Two systems of breech-loading were designed by Sir W. Armstrong, one being the screw system and the other known as the wedge.

The projectiles invented by Major Palliser were specially designed to penetrate iron armour. Cast iron was found to be smashed against armour, wrought iron was too soft to do any damage, and steel in those days was too expensive to be of use. Major Palliser solved the difficulty by making his projectiles of chilled iron, and giving them a cylindrical shape with the pointed or ogival head.

PROJECTILES AND CHARGES USED IN THE BRITISH NAVY.

Photograph by Stephen Cribb, Southsea.

1. Projectile, 16·25 B.L., 1,800 lbs.	9. Projectile, 7·5 B.L., 200 lbs.	17. Projectile, 4-in., 25 lbs.
2. Charge for ” ” 960 lbs. powder.	10. Charge for ” ” 77½ lbs. cordite.	18. 4-in. Cylinder.
3. Projectile, 13·5 B.L., 1,250 lbs.	11. Projectile, 6-in. B.L., 100 lbs.	19. Projectile, 12-pounder.
4. Charge for ” ” 187½ lbs. cordite.	12. Charge for ” ” 29 lbs.	20. 12-pounder Charge.
5. Projectile, 12-in. B.L., 850 lbs.	13. Projectile, 5-in. B.L., 50 lbs.	21. 12-pounder Case Shot.
6. Charge for ” ” 211 lbs. cordite.	14. Charge for ” ”	22. 12- ” 8 cwt. Charge.
7. Projectile, 9·2 B.L., 380 lbs.	15. Projectile, 4·7, 45 lbs.	23. 6- ” Cartridge.
8. Charge for ” ” 103 lbs. cordite.	16. 4·7 Cylinder for Cartridge.	24. 3- ” ”
		25. 1¼-lb. Cartridge.

Experiments are often carried out to ascertain the resisting qualities of various combinations of armour offered to projectiles of varying weights and penetrative powers according to the distances at which they are fired. When iron was used for armour-plating, targets were built in duplication of those provided for the armoured ships. Both the Armstrong and Whitworth 70-pounders fired in the competition trials over 3,000 rounds, or three times the number assigned as the limit to the life of the old cast-iron smooth-bore guns. Of course, the bigger the gun the shorter the life, as a rule.

The French adopted for naval service four different patterns of heavy breech-loading rifled guns, all made of cast iron, and strengthened behind the trunnions with steel rings which were shrunk on. Their weight varied from 21 tons 13 cwt., with a calibre of 10.82 inches, to the gun of 4 tons 18.5 cwt., with a calibre of 6.48 inches, firing projectiles respectively of 476 lb. and 99 lb. The weight of the charge was rather more than one-sixth of that of the projectile. The guns were mounted on wrought-iron carriages and slides constructed on the box girder system.

As the powers possessed a great number of old smooth-bore guns and rifled guns were expensive, several attempts at a compromise were made by lining the smooth-bore guns and converting them into rifled guns, the lining being rifled according to whichever system the power owning the gun happened to prefer at the moment. The Dutch Government is said to have set the example of national frugality in this respect.

How slow the Admiralty was, is shown by the statement of the Secretary to the Admiralty in the House of Commons in March, 1881, to the effect that “at this moment there is not a single heavy breech-loading gun mounted on any of our ships, but by the end of next year a very substantial beginning would have been made towards arming our fleet with breech-loaders.... The Admiralty was driven to the step by the fact that a high velocity was now required for the projectile, that high velocity was only obtainable by a great length of gun, and that to load a gun over a certain length at the muzzle became impracticable under the ordinary conditions of mounting guns afloat.” The Government, it was contended, was now able to profit by the experience which foreign nations had gained, and intended to improve upon the guns which were in use abroad. But whatever may have been the official view, the fact remains that the Admiralty was years behind other nations, that Woolwich, in spite of official claims, discovered nothing that had not been known to be possible a decade earlier at least, and that the Navy was armed with out-of-date muzzle-loaders. Fortunate it no doubt was for this country that it had no wars in which its Navy could be tested against a navy armed with breech-loaders.

In the matter of armour this country owes a debt of gratitude to Sir John Brown, who made the Atlas Works at Sheffield famous throughout the world for the excellence of the armour-plates produced there. Indeed, the records of what he has accomplished seem to indicate that his rule was to surpass whatever his rivals produced, and never to forget that he might be able to learn something from others. His company took up the manufacture of chrome steel, which was patented in America about 1871. When the Italian experiments at Spezzia resulted in the 100-ton gun smashing, in 1876, 22 inches of iron armour and its backing, the French turned their attention to steel plates, as did also Sir Joseph Whitworth, but Sir John Brown thought that better results would be secured with iron plates with steel faces. These compound plates had half their thickness of steel. By 1888 the firm was producing compound plates each 32 tons in weight.

An interesting comparison between French and English methods was made a few years ago[55] by M. Canet, of the well-known French firm of gun manufacturers, in a paper on the heavy naval guns and warships of the two countries. Referring to the latest type of the large weapons then employed at sea, viz., the English 12-inch gun, known officially as Mark IX., he described its method of construction, which has already been alluded to, and pointed out that the corresponding gun in the French navy was of 305-mm. bore (or 12.008-inch) and of 45 calibres in length. The barbette system of gun-mounting, as already explained, owed its origin to French inventiveness, and is preferred in the British Navy; but the French, curiously enough, seem to have preferred the English system of mounting turrets for the guns. The turrets themselves, however, differed from those of the English pattern, the French idea being to make them oval and smaller, so as to offer the narrowest possible target, and this theory was carried into practice even at the expense of the interior roominess. The limited dimensions, however, made it no easy task for artillerists to arrange conveniently inside the turrets all the machinery required, and M. Canet avowed a preference for the English practice of allowing the designer plenty of weight and room inside the turrets or barbettes. There were also structural differences in the methods of the two countries of arranging the armour, and it was claimed that the French oval form, with the other characteristics, had, among other advantages, that of distributing the blows of the projectiles over a greater weight of armour. Another important difference lay also in the method of working the guns. It has been the custom for many years in the British Navy to take up the recoil of the guns by hydraulic buffers, and to use hydraulic pressure to run out the guns again. The French introduced springs, which were compressed by the force of the recoil. Again, hydraulic appliances are preferred in the British Navy for training and elevating the guns, but our neighbours across the Channel prefer electricity. The latter has been tried in the British Navy, the most notable example being one of the super-Dreadnoughts, but the experiment has by no means given satisfaction.

Even more striking differences appeared in the matter of the ammunition hoists, etc. The French battleships, M. Canet said, were equipped with hoists leading direct from the magazines to the guns, and there was the drawback that the guns had to be returned to a certain position to be reloaded, and the muzzle had to be depressed a few degrees below the horizontal to facilitate the loading, the projectile being pushed home with a rammer by the gun crew, whose strength was assisted by a compressed spring. The ammunition hoists on the English battleships, on the contrary, were made in two sections. The lower section raised the ammunition to a relay chamber, and the upper section carried it thence to the gun. This method is held to allow of more rapid firing, as a large supply of ammunition can be placed, prior to an action, in the relay chamber, and the store there, as fast as it is drawn upon, can be replenished from the magazines. It has also been held that in case of a shell bursting in the turret the danger to the magazine would be less, and in M. Canet’s opinion the English method is superior to that of the French. Another matter in which he considered the English to have an advantage was in the manner of loading the guns. How this was done on the French battleships has just been explained. The English gun crews could load the guns at any elevation. The ammunition was carried up in a curved hoist, so that it could be delivered at any point desired, and was pushed home by a hydraulic rammer moving with the gun.

By permission of Messrs. Vickers, Sons & Maxim, Ltd.

12-INCH BREECH MECHANISM
(CLOSED).

12-INCH BREECH MECHANISM
(OPEN).

INTERIOR OF A BARBETTE, SHOWING 12-INCH GUN, H.M.S. “CÆSAR.”

Photograph by Gale & Polden, Aldershot.

Time brings strange revenges. At one period the French were the leading nation in the world in the matter of naval construction, and the English were content to copy the French designs. But in later years England has taken the lead, and not only France but the other maritime powers of the world have been glad to sit at the feet of Britannia and accept the instruction she has been able to impart. Some of these pupils, if pupils they be, have proved themselves exceedingly apt copyists and improvers, and are inclined to think that their own creations are every whit as good as anything this country can produce.

The superiority of the British methods alluded to by the famous French gun-maker were not lost upon French naval architects, and in some of the latest French battleships these methods have been copied. The rapidity of the fire of the big guns would thus, it was expected, be raised to two rounds a minute. Electricity, however, has been retained, as the French consider it to be better than hydraulic machinery for the loading of the guns and movement of the turrets, and more easy of repair in case of damage under hostile fire.

The size and weight of the pieces forming the breech mechanism of the modern guns of large calibre made compulsory the adoption of mechanical means for loading them. There was also the further advantage that machinery was less likely to make mistakes, or to suffer from the accidents which are bound to disable some of the crew in a naval engagement. In some of the earlier battleships, in which the large muzzle-loading guns were fitted, the charge was raised to the gun-mouth by machinery worked by hand-power, and after it had been rammed home by the crew the projectile was inserted and rammed home also, obviously an impossible arrangement when it was sought to introduce rifled explosive shells. When guns were made too large to be withdrawn into the turrets to be loaded, they were loaded by being depressed so that their muzzles just entered a specially cut orifice in the deck in front of the turret, and the loading crew were able to do their work in safety. The drawback to this system was that the gun had to be brought back to the same position for loading, then revolved with its turret once more to the direction in which it was to be discharged, and aimed afresh before its missile could be sent at its mark. The chief advantage of this system was that the gun required a smaller, and consequently less weighty, turret for the protection of its crew. The introduction of the breech-loader enabled the guns to be loaded in greater security, with greater speed, and without interfering with the aim or training of the gun, thereby rendering a more rapid fire possible. Ammunition hoists brought the charge and projectiles right into the turret or barbette more expeditiously and with greater precision than the best-drilled crew, and the men had simply to load the weapon and fire it. The human element came in here, however, in all its uncertainty, and, in spite of the greatest possible care, accidents occurred. A charge or a shell was dropped or caused to explode in some way, and disastrous were the results. Again the necessity for the mechanical appliances caused them to be forthcoming. The projectiles and charges for fighting purposes, which naval strategists declared to be necessary in ever-increasing size and weight, and the greater rapidity of fire which was demanded, made it impossible for dependence on hand power to be retained. After various experiments, both steam power and electricity being tried, hydraulic power was introduced, and has proved more suitable for the purpose than any other method. Now the heaviest projectiles, weighing half a ton or more, are lifted with the greatest ease and exactness to the required position by hydraulic power, are pushed into their places by the same power which does a like office for the charge of explosive, closes and fixes the breech, and does not desist until its task is finished. In the latest appliances, the machinery is made interlocking, so that, at least in the system introduced lately by Messrs. Vickers, no one operation connected with loading the gun can be performed until its immediate predecessor has been accomplished. With a view to securing more rapid and accurate fire this firm has introduced a modification of the breech mechanism by what is known as a “pure couple.” The hydraulic breech mechanisms just alluded to are used for the largest guns, such as the 12-inch weapons, and have also been installed on the Japanese ships for the 10-inch guns. The guns can be loaded at the required angle of elevation, the advantage claimed for this being that the sight can be kept on the target all the time.

The pressure to which guns are subjected when the charge explodes is enormous. One reason why they do not burst is that they have not time to do so. How rapidly the pressure arises against the sides of the gun and then against the projectile to expel it from the bore, was shown by experiments which Sir Andrew Noble conducted some time ago with a 6-inch gun of 100 calibres length of bore. Practically instantaneously with the ignition of the charge, that is to say in about the four-hundredth part of a second, a maximum pressure against the interior of the gun of 22 tons per square inch was reached, but this declined to about 13 tons per square inch in about the twelve-hundredth part of a second more. But by that time the projectile had left the gun, and was rushing, faster than the eye could follow it, towards its mark.

The English 12-inch (Mark IX.) gun consists of a steel tube, wound practically from end to end with layer after layer of steel ribbon or wire of very great tensile strength. This tube is known as the A tube, and may be called the hollow heart of the gun. As much as a hundred miles of wire will be used for one of these guns, and, of course, for the newest guns, the 13-inch weapons, such as have been placed in the latest super-Dreadnoughts, or the 15-inch guns which it is said will be placed in the Dreadnoughts of 1912 or the year after, the amount is a great deal more. The greatest thickness of layers is placed round the breech of the gun, where the strain is most severe, and each succeeding layer is wound on with increasing tension, though to the ordinary observer the first layer seems to fit so tightly that nothing could be tighter; but the gun makers know better. All along the chase or fore part of the tube another tube, called the B tube, is shrunk on to ensure that it shall be the tightest fit possible. Then, over a portion of the B tube, and also over a portion of the winding, that part of the gun known as the breech jacket is shrunk. Apparently everything is so strongly fixed together that nothing can cause the parts to separate, but the gun makers know this is not so, for into this jacket a bush is screwed to prevent any movement of the A tube, so far as the jacket is concerned. The A tube itself contains a thin steel inner tube inserted from the breech and fixed in position by the breech bush. It is this inmost tube which has to bear the wear and tear caused by the firing, and suffers from erosion, due to the gases generated by the explosion of the charges, and has to be replaced by a new tube when it is no longer fit for service.

THE 12-INCH GUNS OF H.M.S. “NEPTUNE.”

Photograph by Stephen Cribb, Southsea.

Gun makers have always responded cheerfully to the challenge to penetrate the hardest armour of the time, and have succeeded in producing weapons which are able to penetrate any armour now carried. The problem at present is to increase the range at which the penetrative power may be exercised. This can only be attained by the increase in the length of the gun and the use of explosives developing higher pressures in order to obtain higher velocities. The British gun of 45 calibres and 9.2 inches diameter is about to be superseded by one of 50 calibres, and the 40-calibre gun carried in some of the latest ships is being superseded by the 12-inch gun of 45 calibres.

Twelve-inch guns of 45 calibres and 10-inch guns of 50 calibres have been installed in the new ships, built at Elswick recently, for the navies of Japan and one of the South American States.

Greater length means a greater muzzle energy, higher velocity, and increased power of penetration. The latest guns, too, have shown that the manufacturers have been considering the advisability of effecting a certain amount of redistribution in the thicknesses of the different parts of which the gun is built, notably the tubes, wires, and jackets, and the adoption of a uniform type of rifling. The theory was that the rifling should be increased as the grooves passed down the tube, so that a gradually increasing twist should be given to the projectile, but it is now held that no advantage is obtained by this method, whatever may have been the case in the past, and that the uniform rifling will give better results as to accuracy, muzzle energy and velocity, and inflict no greater strain upon the gun or shorten the “life” of its tube. The trials already made have shown that uniform rifling for modern high velocity guns has resulted in giving greater range and greater accuracy in shooting.

The war between France and Germany in 1871 brought machine guns into notice. Great things were expected by the French of the mitrailleuse, and some of the patriotic Paris newspapers at the time published glowing prophecies of the number of Germans each gun could be depended upon to kill in a few minutes, with the result that, according to their calculations, there would be no Germans left after a few days to continue the war. But events turned out otherwise; the mitrailleuse failed, and the Germans were victorious. This machine gun was very defective, and served to advertise by contrast the Gatling, Nordenfeldt, Gardner, and Maxim automatic guns, named after their respective inventors. Of these the Maxim has been so improved that it is considered to be superior to any of the others. The machine guns fire, according to the number of their barrels and their calibre, from four hundred to six hundred or more shots per minute, at a range equal to that of the best infantry rifle, and can be sighted with deadly accuracy.