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forward of loose-fitting parts in the interior, and against the sea by the entrance of water. Rotation is imparted to the projectile by a tail 2 feet long with spiral feathers, vide Plate 9, of Part III. A very similar trial of a pneumatic gun is said to have taken place in Germany in the spring of 1888. J. W. Graydon, of the United States, Graydon's has proposed a pneumatic gun, which he calls a "torpedo thrower," in thrower. torpedo which a much greater air pressure and velocity of projection is adopted than in the Zalinski gun. This enables a much shorter tube to be used, and presents considerable advantages. Graydon states that all danger of premature explosion of the high explosive employed is prevented by his system of charging the projectile, mentioned below, in explosive shells. At the same time it must be noticed that while the committee who tested his shells reported some measure of success, they also reported occasional failure. Graydon's pamphlets omit to notice this, but it may be seen in Information from Abroad, 1888, p. 377.

shells.

For some years it has been laid down that high explosives would Explosive be used for the bursting charges. Shells of forged steel resist the action of black powder, the use of which has been discontinued for Black armour-piercing projectiles. Experiments, however, were needed to powder. enable a definite conclusion to be arrived at. It had been proved at Lydd some years since that Grüson's ingenious plan of filling shells with compounds which were only mixed and rendered explosive by the rotation of the projectile in flight, could be carried out without danger to the gun. More recently it has been shown that compounds such as Roburite, or Bellite, could probably be fired with safety, which Roburite, would burst a shell with great violence. These two compounds resemble each other very closely. Bellite mainly consists of ammonium nitrate and di-nitro-benzole. Experiments made with both these compounds have shown an extraordinary power to resist ignition except by means of a detonator. Roburite has been fired in mines and explosive mixtures of gas to exhibit its close approach to entire absence of flame. Bellite has been mixed with powder in a mine, and the latter has been fired without igniting the Bellite. has been crushed on iron plates by the fall of heavy weights, and has been melted in a coal fire without explosion.

Bellite.

J. W. Graydon, of the United States, has also brought forward a Other comcompound for which he claims safety as an explosive for shells. He pounds. has also fired dynamite in shells subdivided in pellets with some measure of success, and high explosive bursting charges have also been fired in shells by Smolianinoff and Snyder. Steel common shells have a capacity in proportion to their weight which admits of a very large bursting charge. Still, as time went on, nothing was introduced

Armour.

Deck

armour.

Meppen

results.

into the British service in the shape of a stronger explosive, probably for two reasons: One, that until steel shell could be made to perforate armour without setting up, it seemed hopeless to expect the explosive to remain intact under the heat and shock due to the process of penetration.* Armour has been growing harder and harder; the behaviour of the early forged steel shell was thought admirable because they perforated wrought iron without changing their form, but it has only been during the last three or four years that steel shell have resisted setting up on impact against steel-faced or solid steel armour, and even now it remains to be seen whether armour may not be given so hard a surface as to ensure the fracture or setting up of the projectile. Chilled iron armour never fails to break up the best projectiles. It may well be concluded that so intolerable a thing as a bursting shell must be kept out even at the cost of fracture of the armour to almost any extent. This conclusion is one especially opposed to the line taken by our own and foreign naval authorities, but this conclusion may be adopted eventually, if shells containing high explosives are successfully driven through the present types of armour so as to burst in the interior of the ship. A second way in which high explosive charges may act is by shattering the plates themselves on their impact with the exterior face, but this is of the two a less serious form of injury; and this leads to another branch of the question, on which some misapprehension appears to exist. It has been stated that the deck plates when they become visible, or open to be struck by shot, constitute a thinly-armoured target in the sense of a weak defence. This, no doubt, would be the case if it were not for the fact that the decks can be struck only at very oblique angles indeed. The principle governing the thickness of deck armour is that its resistance to shot glancing on it at 10° with the face shall be equal to the resistance of the side armour of the ship when struck directly. It follows then that a shot which strikes a deck at, say, 9° with the face, will have less power to penetrate than the same shot would have if it struck the vertical armour of the same ship directly; and if this is true of shot, another element exists in live shell, namely, the necessity for very quick explosion of the bursting charge. It was found at Meppen in 1882 that no fuse could be devised with quick enough action to cause a shell in curved fire to burst on the roof of a casemate before it glanced, and it was found that bursting after contact was past, a very insigni

* Recent trials have suggested that Bellite might do so. The Swedish Government have purchased a delay action fuze designed to adapt this explosive to the perforation of armour.

deck

armour

ficant effect was produced. Against ships' decks at Eastney, common Eastney and Palliser shell were found occasionally to produce good effect, but it is a question whether Palliser shells were not more efficient than trials. common shell, and it is quite clear that steel projectiles fitted with delay-action fuses for attacking vertical armour would not explode effectually on glancing on deck plates.

armour.

Altogether there is much to be worked out at Lydd, especially with regard to the effect of detonation against the surface of really thick The value of experiments when thin plates are used and when penetration forms one element of the destructive action is comparatively little. France has taken the lead in the question of explosives. Whether Melinite is the best explosive may be questioned, Melinite. but it is one of the best, and it is obviously far better to have learned how to use one of the best explosives efficiently, and to have secured a supply of it, than to be caught at the moment of war breaking out in an experimental stage of inquiry with two or three alternative compounds, with our minds not made up which to adopt; with but limited experience possessed by our chemists, none at all by our manufacturers and combatant officers, and no supply in store.

of steel.

To those who have the opportunity of studying the question of Structure steel, more particularly as to its structure, two papers may be specially commended, one by William Metcalf in the Transactions of the American Society of Civil Engineers, and one by Captain Couhard of the French Artillery, in the Revue d'Artillerie. An excellent translation of the latter appeared in the Proceedings of the Royal Artillery Institution, and notices of both papers in the Engineer of April 6th, 1888.

on In

Mr. Longridge wrote an interesting paper on "Internal Ballistics," Longridge which was rejected by the Institution of Civil Engineers, and published ternal by Messrs. Clowes & Sons, and reviewed in Engineer of February 3, Ballistics. 1888. This discussed the question of burning of powder in the bore, referring particularly to the results of investigations made by M. Sarrau in France. Mr. Longridge considers that our adoption of cocoa powder has been too precipitate.

ment of

CHAPTER III.

QUICK-FIRING GUNS AND SMALL ARMS.*

Develop- THE development of quick fire has made considerable progress quick fire. during the year. Stress has been laid on the rapid destruction which

Lord

on naval

may be effected of the unarmoured portions of ships of the Citadel and protected classes. On the other hand, it will become increasingly difficult for unarmoured vessels however small to approach armoured ships well supplied with quick-firing guns, and the old armoured vessels of the Minotaur class possess an unexpected advantage in their power of resisting quick fire from light guns. The smaller quick-firing pieces, namely, 6-pounders and 3-pounders, have been supplied to most ships, but larger ones, similar to those described in the Annual for 1887, although approved, are not yet issued for service. These will probably consist of a 36-pounder and a 6-in. gun. France and Russia have made trials with a 33-pounder of Hotchkiss construction. Krupp has made experiments with R. F. guns up to a 66-pounder.

Lord Armstrong, on Sept. 26th last, spoke at a meeting of shareArmstrong holders of Armstrong, Mitchell, & Co. on the work done recently, defence. especially dwelling on the development of quick fire. Lord Armstrong said that the new Elswick 6-in. and 43-in. quick-fire guns, weighing 5 tons 15 cwt. and 2 tons 1 cwt., perforate 15 in. and 10.5 in. of wrought iron respectively at the muzzle. They are mounted on special carriages, provided with shields, and fitted with special gear for handling and aiming. He said that in Admiralty trials last year the 42-in. gun fired ten rounds in 47 sec., while an ordinary breechloading gun of the same calibre took 5 min. 7 sec. to fire the same number of rounds. At Shoeburyness a few weeks previously the power of these guns to pour in a rapid fire with accuracy was exhibited by a target 6 ft. square being hit five times running in 31 sec. at 1300 yards range. Lord Armstrong added that the Admiralty have adopted both these guns for the service. He dwelt on their value in resisting

*List of Authorities. Captain Stone's paper in R. A. I. Proceedings; and Colonel Slade's pamphlet on Small Arms; also the Times, March 23, 1889.

the attack of torpedo boats. A torpedo boat sighted at 1300 yards by a war vessel having a broadside armament of three ordinary 6-in. service guns would be open to their fire at the rate of about two rounds per minute until she came to within 200 yards, at which range she might probably discharge her torpedo. At the speed of 20 knots an hour she would traverse the 1300 yards of space between the range at which she was first seen and her striking range, in about two minutes. The three guns above mentioned might therefore fire twelve shots at her while running this distance; if, however, she had three rapid-fire 44-in. guns, she could fire seventy-two shots during the two minutes specified. For this quick fire to be delivered without obstruction, smoke must be got rid of as far as possible. Happily, a powder has now been made by the Chilworth Company which has so little smoke as to present little obstacle to the sighting of the gun. This powder, with a charge of about two-thirds the weight of the ordinary powder charge, gives a velocity of from 2300 ft. to 2400 ft. as compared with 2000 ft. due to the ordinary powder charge.

Applying the advantages of such guns to the case of protected cruisers, great results follow. In August last was launched for the Italian Government a cruiser named the Piemonte, which is a further Piemonte. improvement on the Esmeralda type; her displacement is only 2500 tons, yet her speed is to be 21 knots-or 24 miles per hour, and the coal capacity of her bunkers is sufficient to steam about 13,000 miles at her most economical speed without re-coaling. Her offensive power is, he observed, enormous. "In addition to a complete torpedo equipment and full complement of Hotchkiss and Nordenfelt guns, she carries an armament of six 6-in. and six 43-in. guns of improved type; and she is capable of discharging against an adversary in a given time twice the weight of shot and shell that could be fired by the largest vessel now afloat, not excluding the leviathan battle ships of five or six times her size, which could ill withstand the torrent of shell which the Piemonte conld pour into the large unarmoured portion of their structure." Lord Armstrong points out with truth that the increased rapidity of the quick-fire gun offers the advantage of an increased number of guns without their increased weight of protecting shields and guns, or the increased number of men necessary to serve them; and he specially recommends the heavier quick-firing guns to be used in the defence of harbours, in conjunction with Major Watkin's system of position finding.

machine

The Maxim machine gun rifle bore was submitted for trial by our Maxim Government in March, 1887: it was not to exceed 100 lbs. in weight; it was to fire 400 rounds in one minute, 600 in two, and 1000 rounds

gun.

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