shot from rifled guns at short range. Mr. Whitworth was the first to demonstrate these facts, and to show that 44-inch plates

on the 'Trusty' were no match for his steel bolts, which went through the plates, and which with a few more rounds would have sunk the ship. These and other subsequent experiments showed the weak points in the build of the Warrior' class, and suggested new appliances and new constructions, such as we have endeavoured to describe.

The Warrior' and 'Black Prince' (of the first of which we give an engraving in the frontispiece) are, nevertheless, noble vessels, well protected with armour-plates to a depth of 6 feet under the line of floatage, and for about one-third of their lengths have a certain portion of the bow and stern unprotected and open to the enemy's shot. The whole of the sides are, however, well secured with 44-inch armour-plates, with 18 to 20 inches thick of teak and oak backing, and if to these be added two transverse armour-plated bulkheads, we have some idea of the security which those vessels afford when encountered by a vessel of equal or of superior force.

As regards the build of these vessels, they do not contain the elementary strength of the 'Bellerophon,' as exhibited in the longitudinal keelson and cellular form of construction. They are, however, well and securely built, with a partially constructed double bottom, and longitudinal frames and transverse ribs, as shown in section, at ▲ ▲ ▲ ▲, fig. 91. These frames are of no great depth, but they add to the strength and stiffening of the angle iron of the transverse ribs, being united by a solid plate from the centre keelson, A, round the bilge to the bottom of the armour-plating at B, which renders that part of the structure of greatly increased strength.

The decks are covered with iron plates, which, to a certain extent, answer the purpose of stringers, but they are defective in those parts, both as regards the tensile and compressive powers of resistance, and are inferior in strength to the corresponding parts in the 'Bellerophon.'

These were the first ironclad vessels of any great magnitude which made their appearance as ships of war, and considering that they were built previous to the experiments on armour plates that have since been made, they approximate closely to the construction of those founded upon more certain data.

Notwithstanding what has been said on the build of iron

plated vessels, and their limited powers of resistance to guns of large calibre, it is evident, from the experiments to which we have referred, that the question of security against shot and shell is one of great importance. There cannot exist a doubt that vessels can be built large enough to carry armour-plates 10 inches thick, but it remains to be seen whether such vessels would or would not be almost totally unmanageable in action; and we have yet to learn to what extent it would be prudent to build such monster ships, and embark the public money in speculations where the principles on which they are founded are not fully developed. We have already noticed the dangerous nature of armour-plates when perforated and driven through the backing into the interior, making a large and dangerous breach in the side of the ship. With such heavy ordnance to contend against, it is a question whether, in so far as regards the officers and crew at close quarters, the loss of killed and wounded would not be greater with than without the armour-plates. In this latter case they would only be exposed to the shot and the splinters from the sides or bulwarks of the ship; whilst, on the other hand, in the case of the armour-plates they would not only be exposed to the entrance of shot and shell, but to large fragments of iron driven forward, with the most deadly effect to those who happen to be in the way of the range of these destructive missiles. This is one of the reasons why we advocate a clear deck and plenty of room for an active crew to work the guns. Open ships entirely free from obstruction and no harbour for skulking is what the British sailor requires, and what he would infinitely prefer to the imperfect shelter of armour-plates. He would then strip to his work, fight with greater courage, and being sure of his ship with thick plates, as we have recommended, along the water-line, his only object would be to disable his adversary and give a satisfactory account of the enemy.

If this system, of simply protecting the ship by a belt of armour along the water-line with free and open decks, applies to the case of vessels where the batteries are concentrated amidships, the same principle will also apply to the turret plan. It is well known that the great advantage of the turrets consists in the power to revolve and work the guns; but this does not compensate for the crowded state of the interior, and the

accidents that may occur in driving in large pieces of armourplates and backing, to the discomfort of the inmates and, in all probability, the destruction of both men and guns. These are difficulties which require consideration; and till such time as we have further experience, these and other suggestions will require to remain in abeyance for further development. In the interim, we have to recommend attention to the foregoing

Fig. 92.

B

principles of construction, which we have endeavoured to urge on the attention of the Government; and as most of them are founded on experimental research, we have the greater confidence in their development for the increased security and benefit of the British Navy.

4. Before closing this part of the subject, it may be desirable

to direct attention to what we are unable, in the absence of experiment, confidently to recommend. It is, however, of some importance to ascertain what would be the effect of a water-shield running parallel with the armour-plating all round the ship, from the line of floatage to a depth of 4 feet under that point, as exhibited in the section, fig. 92, at A. The object of this construction would be to receive any accidental shot that strikes the vessel with a force that would penetrate the armour-plates, the backing, and the skin of the ship. In the event of such an accident, it appears obvious that water, which presents a powerful resistance to the entrance of bodies at high velocities, would be an element into which a spent shot at greatly reduced velocity might come to a state of rest. If we are correct in these views the vessel would require to be built with the double bottom carried up to the lower deck, B; and from that point to a depth of 4 feet, the sides would be enlarged to the dimensions shown in the section. Should this arrangement be found advantageous, it would not be necessary to retain the tank full of water excepting only in the time of action, and that for the exclusive purpose of preventing the entrance of shot into the interior below deck, and thus to render the vessel what is considered unsinkable under every condition of attack or defence.

Next to water, sand is the most powerfully-resisting medium, but it is unsuitable for such a purpose on account of its weight; and as the water-space can be filled and emptied at pleasure, it is probably in more respects than one preferable to that of sand or any other solid lining. We hope the time is not far distant when we may be able to prove the efficacy of these views by a series of experiments calculated either to confirm or abandon this principle of protection.

5. The limits of this work will not admit of an extended description of the different armour-plated vessels of war as designed for this and other maritime nations: it may, however, be convenient to give the dimensions, tonnage, armaments, and other conditions of some of the leading vessels of the ironclad fleet. For this purpose we have selected and tabulated ten vessels; from which it will be seen that, with three exceptions only, most of the vessels are of large tonnage, and some of them carrying heavy guns.