Page:Encyclopædia Britannica, Ninth Edition, v. 17.djvu/298

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286 NAVY by any means certain that some method may not be devised of securing the requisite reserve of buoyancy by other means than armour-plating. Were this accomplished, the area of the armour might be diminished, and its thickness increased in a corresponding degree. The ship would then compiise a very strongly plated central citadel, surrounded and supported by an unarmoured raft constructed on a cellular system, or containing some buoyant substance such as cork, which, without offering any material resistance to the passage of pro jectiles, would not be deprived of its buoyancy by penetration." .... "At present we find ourselves compelled to regard the attainment of a very high degree of offensive and defensive power united with real efficiency under sail as an insoluble problem ; and we believe that our transmarine possessions, and other important interests in distant parts of the world, will be more effi ciently protected by the establishment, where requisite, of centres of naval power, from which vessels of the Devastation class may operate, than by rely ing upon cruising ships of such limited fighting power as the Monarch. We think, however, that a class of vessel in many respects resembling the Monarch, although much smaller and less costly, ought to form part of the British navy." In 1873 Italy was contemplating the construction of the Duilio " and "Dandolo," large turret ships of the "Devastation" type, but intended to mount four very heavy guns which were being constructed by Sir William Armstrong & Co., to be protected by armour 22 inches in thickness. It was necessary that England should not be behind, and the "Inflexible" was laid down. She was to carry four 60-ton guns in two revolving turrets, similar to the "Devastation," except that, in order to obtain right-ahead fire of all four guns, and to meet the objections raised by naval officers and in parliament against the lowiiess of the upper deck of the "Devastation" class, the turrets were placed " en echelon," the fore most turret on the port side and the after one on the starboard side, and a superstructure was erected between them along the centre of the ship. The belt also beyond the citadel was omitted, and a sub merged armour deck, of 3 inches in thickness, replaced it at the ends. This deck descended forward and helped to strengthen the ram. The armour on the sides was to be 24 inches ; before the ship was completed, however, compound armour had been intro duced, which allowed the thickness on the turrets to be reduced to 16 inches. The total weight of armour was 3155 tons. To enable this great -weight to be carried, to provide stability when injured, and to allow all the guns to fire in line of keel, the breadth, which had not before exceeded 60 feet in sea-going ships of war, was increased to 75 feet, the utmost which existing docks allowed. The length was 320 feet, and the displacement reached 11,880 tons. The horse-power was 8000, and this gave her, after she was launched in 1876, a speed of 14f knots, and when fully equipped at Malta 13 87 knots. She is rigged as a brig. This is, however, only an arrangement for peace time. In consequence of an important question having been raised in the press and in parliament as to her stability in the event of the unarmoured ends being badly damaged in action, a committee was appointed, who reported that it cannot be said that the armoured citadel is invul nerable, or that the unarmoured ends are indestructible, although the character of the risk they run is different. But in our opinion the unprotected ends are as well able as the armoured citadel to bear the part assigned to them in encountering the various risks of naval warfare, and therefore we consider that a just balance has been maintained in the design, so that out of a given set of condi tions a good result has been obtained." It was subsequently laid down in parliament, by the responsible minister, as a guiding principle in such questions, that in a ship of Avar there should be the greatest possible offensive power, and the defensive arrangements should be such as to ensure her as far as possible, and in equal degrees, against all the various modes in which she may be disabled or destroyed. From this it would follow that it should not be in the power of the enemy to disable the ship by one single blow delivered by any means at his com mand, if this could have been prevented by causing other defences, where he has not this power, to surrender a portion of their strength to succour the weak part. Amplifying this principle, it may be said that there should be defence for the propelling power, for the steering power, and for the floating power against the gun, the ram, and the torpedo. To a very large extent the defence against the two last named must rest with the officer in command ; but to resist them he must retain command of speed and steering gear. He therefore requires that these and his floating power should be equally defended against the gun, which he cannot avoid. The avoidable weapons, the ram and the torpedo, are provided against in all ships, even in the "Inflexible," far less than is the unavoidable weapon, the gun. The equality of defensive power in view of all three weapons is obtained by reckoning as part of the defence against the ram and the torpedo the skill and vigilance of the seaman. The "Ajax" and "Agamemnon" were laid down in the year the " Inflexible" was launched (1876). They are of the same type but smaller, carrying only 38-ton guns. Of this type also are the " Colossus" and "Edinburgh," commenced in 1879, and now (1883) approaching completion. They are the same length as the "In flexible," but 7 feet narrower. As they are of later date than the "Iris" (the first war-vessel built entirely of steel), steel is employed almost entirely in their construction, and they have steel -faced armour. They are to be armed with 43-ton breech- loading guns in the turrets, and four 6 -inch 4-ton guns on the superstructure. The "Conqueror" is another steel ship, designed especially as a ram, having one turret for two 43-ton guns, and four 6-inch guns unprotected by armour. The "Collingwood," commenced in 1880, has a different arrange- Barbette rnent. In the endeavour to increase the protection of the vital ships, parts, and at the same time to increase the offensive power without going into extravagant dimensions, it was inevitable that the space to be covered should be reduced, and the armour concentrated. The guns being large, it was thought they would not suffer by being mounted "en barbette," the loading being still done under cover. By these means the revolving turrets were got rid of, and the citadel was no longer required to protect the loading apparatus. By placing the barbette towers some distance apart it became possible to mount several broadside guns, not indeed protected from the front, but sheltered from raking fire by an armoured screen extending from the barbette towers to the ship s sides. This then is the design of the "Collingwood" class. The central belt, which rises but little above the water, has 18-inch compound armour, the barbette towers 12-inch, and the screen 6-inch. Communication is maintained by means of armoured vertical hollow cylinders between the towers and the protected part of the ship below, whence the supply of ammunition is derived. She will mount four 43-ton guns in the towers, six 4-ton guns in the broadside, and numerous lighter guns. The Rodney, " "Howe," " Camperdown," "Anson," and "Benbow" are similar to the "Collingwood," but they will carry 63-ton guns instead of 43-ton. Possibly the " Benbow " may have two exceeding 100 tons instead of the four 63 -ton guns. The cruising ironclads have also continued to advance. In 1873 Cruising the "Alexandra " was commenced, of the " Sultan " type. In this iron- vessel four powerful guns in the central batteries fire in line of keel clads. ahead, and two astern. She has thicker armour than the " Sultan," and a bulkhead was placed across the main battery, cutting off the two foremost guns from the rest. In the same year the " Temeraire" was commenced. She differed from the " Alexandra " in having barbette towers forward and aft, instead of the upper deck battery, the 25-ton guns mounted in them being made to descend, on being fired within the tower, for loading. The towers communicated with the protected part below by means of hollow armoured cylinders. She fires three heavy guns from her armoured batteries in line of keel ahead. Then came the " Shannon," a much smaller vessel, in which the water-line is protected by an armour belt to within 60 feet of the stem, whence a submerged armour deck extends forward ; a bulkhead rises from the same point, which covers two guns firing ahead. The remainder of the guns are unprotected, except from right-ahead fire. She was designed for an armoured cruiser, capable of engaging a second-class ironclad. The "Nelson" and "Northampton" followed, but they have central belts and armoured decks at each end, and armour-covered guns for stern as well as bow fire, with eight broadside guns between. In 1878, when Russia was threatening Constantinople, three ships then building in England were bought from the Ottoman Government, the "Belleisle" and "Orion," belted ships with a central battery and a gun at each of the corners, and the "Superb," broadside ironclad. At the same time the "Neptune," a masted turret ship like the " Monarch," building for Brazil, was bought. The " Imperieuse" and " "Warspite," now building, of steel, are the latest type of ironclad cruisers. They are like the " Nelson," but with barbette towers of the French type forward and aft and amidships instead of the partial battery. Recent ships are furnished with every appliance that modern science can devise to augment their efficiency and power. The turrets and the turn-tables of the barbette ships are moved by hydraulic power ; the guns are loaded and worked by the same power, and are fired by electricity if desired. Electricity is used to light the batteries and the ship generally, the old fighting lanthorn, or indeed any other, being extinguished by the shock of discharge of modern artillery. The capstan, the steerage of the ship, the gun, the ram and torpedo, the pumps and ventilation, and electric light all require machinery in every direction, so that the ship has become a factory. A large proportion of the crew are relegated to the stokeholds, and but little is left that recalls the war-ship of our fathers. The "Polyphemus" is the only other vessel to be here men- Experi- tioned. She is hardly an ironclad ; she comes under the head of mental special ships, and is described in the Navy List as a double screw ships, torpedo-ram of 2640 tons and 5500 horse-power. Her shape is cylindro-conical, of steel the part above water being covered with 3 inches of steel. She is intended for ramming and to use the Whitehead torpedo. Her only other armament is the machine gun. These guns are mounted in revolving towers. In this ship the first attempt was made in a sea-going vessel to use the locomotive boiler (working with fresh water) with closed stokeholes and forced draught. Mr Thornycroft and other torpedo- boat builders had used one such boiler in boats with great success. As its weight was very considerably less than the ordinary type of