The succession of cause and effect which has produced the present ship-of-war will be traced in rapid outline, in order to leave as much room as may be for the description of the essential feature of the ship herself as she now exists.
Two chief factors concur to a ship-of-war—motive power and fighting power. The displacement of sails by engines, and the progressive development of the latter, are features of the general progress of the century. The engines of a ship-of-war are differentiated from those of merchant ships chiefly by the necessity of protection. This affects their design, which must be subordinated to the requirement of being as far as possible below the water-line. The further great protection now afforded is incident rather to the use and development of armor as a part of the fighting power.
Fighting power divides into offensive and defensive. Armor now represents the latter. The fighting ship in every age is the product of the race between the two, and in the nineteenth century this was unprecedented in the ground covered and in the rapidity of the pace, due to the increased power of dealing with materials, already alluded to.
CONTEST OF ARMOR AND PROJECTILE
The modern contest began with the introduction of horizontal shell fire in the third decade of the century. This term must be explained. It has been said that all ships’ guns up to 1815 threw non-explosive projectiles. In practice this is true; although Nelson alludes to certain shell supplied to him for trial, which he was unwilling to use because he wished not to burn his prizes, but to take them alive. A shell is a hollow projectile filled with powder, the idea of which is that upon reaching the enemy it will burst into several pieces, each capable of killing a man, and the flame not impossibly setting woodwork on fire. It was necessary that the powder within should not explode from the combustion of the cartridge of the gun, for if it did its force, combined with the latter, might burst the gun; yet the process that should result in bursting must begin at that moment or else it would not take place at all. This difficulty was met by a short column of hard, compressed powder called the fuse, which extended from the outside to the inside of the shell. The outer end was inflamed by the charge of the gun, but from its density it burned slowly, so that the charge of the shell was not enkindled for five, ten, or more seconds. This expedient was in use over a century ago; but owing to imperfections of manufacture, no certainty was attained that the fuse might not be driven in or broken by the force of the discharge, or the shell itself be cracked and so explode prematurely. Shell, therefore, were fired with very light charges; and, to obtain sufficient range—go far enough—they were used in very short, very thick guns, called bombs or mortars, to which great elevation was given. Such firing, because the shell flew high in the air, was called vertical firing, in contradistinction to the fire of the long gun or carronade, called horizontal fire because their projectiles rose little above the level.
The destructiveness of shell from ordinary guns was so obvious, especially for forts to use against wooden ships, that the difficulties were gradually overcome, and horizontal shell fire was introduced soon after the cessation of wars allowed men time for thought and change. But although the idea was accepted and the fact realized, practice changed slowly, as it tends to do in the absence of emergency. In the attack on Vera Cruz, in 1848, Farragut was present, and was greatly impressed, as with a novelty, by the effect of what he called the “shell shot,” a hybrid term which aptly expresses the transition state of men’s minds at the time. I remember an officer who entered the navy in 1840 telling me the respectful awe and distrust with which his superiors then regarded the new weapon, a very few of which for each gun were supplied tentatively. Ten years more, however, saw a great change, and in 1853 the attack of the Russian squadron of wooden sailing-ships upon the Turkish vessels in the Bay of Sinope gave an object-lesson that aroused the naval world to what wooden ships must expect from horizontal shell fire. In a few minutes three out of seven Turkish frigates were in flames; while of nine sailing-ships and two steamers only one of the latter escaped.
HORIZONTAL SHELL FIRE
The Crimean War followed quickly, and in 1854 the wooden steamships of the line of the allies, vessels identical in fighting characteristics with those of Trafalgar, attempted to silence masonry works at Sebastopol. Though the disaster was not so great, the lesson of Sinope was reaffirmed. Louis Napoleon, a thoughtful man though scarcely a man of action, had foreseen the difficulty, and had already directed the construction of five floating batteries which were to carry armor. Before the war ended these vessels attacked the forts at Kinburn, which they compelled to surrender, losing, themselves, no men except by shells that entered the gun ports. Their armor was not pierced.
Horizontal shell fire had called for iron armor, and the two, as opposing factors, were now established in the recognition of men. The contest between the two sums up the progression and the fluctuations of military ideas which have resulted in the battle-ship of to-day, which, as the fleet-ship, remains the dominant factor in naval warfare, not only in actual fact but in present probability. From the first feeble beginnings at Kinburn to the present time, although the strife has waxed greatly in degree, it remains unchanged in principle and in kind. To exclude the shell, because, starting as one projectile, it became many after penetration, in what does it differ from excluding the rapid-fire gun, whose projectiles are many from the first, and penetrate singly?
There occurred, however, one singular development, an aberration from the normal line of advance, the chief manifestation of which, from local and temporary conditions, was in our own country. This was the transient predominance of the monitor type and idea; the iron-clad vessel, with very few very heavy guns, mounted in one or two circular revolving turrets, protected by very heavy armor. The monitor type embodied two ideas. The first was the extreme of defensive power, owing to the smallness of the target and the thickness of its armor—the hull of the vessel rising but little above the water—the turret was substantially the only target. The second was an extreme compression of offensive power, the turret containing two of the heaviest guns of the day, consequently guns of the heaviest penetration, which could fire, not in one direction, nor in several, but in all directions as the turret revolved, and which were practically the sole armament of the ship. The defensive power of the monitor was absolute up to the extreme resisting endurance of its armor. Its offensive power must be considered relatively to the target to which its guns were to be opposed. If much in excess of that target’s resistance, there was waste of power. Actually in our Civil War monitors were opposed to fortifications, except in one or two instances when they had to contend with the imperfect structures which the Confederates could put afloat. The target, therefore, was not in excess of their gun power. Moreover, being for coast warfare, the monitor then was necessarily of small draught and small tonnage. Her battery weight, therefore, must be small, and consequently lent itself to concentration into two guns, just as the battery weight of a schooner a century since found its best disposition in one long traversing gun.