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.