So long as sails remained the sole motive power, warships retained the same classification as they had received in the seventeenth century. “Up to the time of the Dutch Wars,” says Admiral Colomb, “ships were both ‘royal’ and of private contribution; of all sorts and sizes and ‘rates.’ Fighting was therefore promiscuous. Fleets sailed in the form of half-moons, or all heaped together and, except for the struggle to get the weather gage, there were no tactics. Actions were general.” Then, in order to protect their fleets from the fire ship, the Dutch first introduced the Line of Battle: “in which formation it was easy for a fleet to leeward to open out so as to let a fire ship drift harmlessly through.” And so the efficacy of the fire ship was destroyed. “But now, with a Line, each ship had a definite place which she could not quit. Hence the diversities in sizes began to be eliminated. The weakest ships, which might find themselves opposite the strongest, were dropped for ships ‘fit to lie in the line,’ i.e. for what were afterwards called ‘line-of-battle ships.’ These ships would be individually as powerful as possible, only subject to the objection of putting too many eggs in one basket. Uniformity would thus be attained. The fleet of line ships, however, required look-outs or scouts, which could keep the seas and attend, yet out-sail, the fleet. Hence the heavy frigate. Lastly, there was the much lighter attendant on commerce (either by way of attack or defence), the light cruiser.”

Although this differentiation of types was based ostensibly upon displacement or tonnage, in reality it was formed on a more scientific basis. Admiral Sir George Elliot demonstrated, in 1867, that the real basis was not a rule of size, but a law of safety, similar to that which operates in the natural world; a law so important that it should under no circumstances be disregarded. He showed that sailing ships conformed to this law. He showed that the reduction of a vessel’s size, for instance, endowed her with smaller draught and an increased speed; that the dispensing with one quality automatically gave another in compensation; and that thus the weakly armed vessel always possessed the means, if not to fight, to escape from capture.[173]

With the coming of steam and armour, all this was changed. Size had now no inherent disability; on the contrary, the larger the ship the greater the horse-power which could be carried in her, the greater her probable speed and sea endurance. The small ship had no advantages. The old classification had clearly broken down. The first ironclads, the Warrior and her successors, although of frigate form, belonged to no particular class; they were of a special type intended to cope with the most powerful ships afloat or projected; and subsequent ships were designed with the same end in view. These ships being faster as well as more powerful than those of a smaller size, there was no object in attempting to build others of a frigate class for the purpose of outsailing them.

As material developed, and as the warship became more and more obviously a compromise between conflicting qualities, differentiation of types was once more seen to be necessary. Attempts were made to classify on the bases of displacement, material, defensive and motive power, service, system of armament. In the end British construction divided itself into two categories: armoured and unarmoured vessels. And each of these categories was subdivided into classes of ships analogous to those of the old sailing ships.

But, during the transitional period 1860 to 1880, when armour and iron ships, steam engines, rifled guns, and fish torpedoes, were all in their infancy and subject to the most rapid development, no such classification was recognized. The circumstances of the Crimean War, with the adoption of armour and the sudden and enormous growth in the unit of artillery force which took place soon afterwards, led to the first differentiation of ironclads, into ocean-going and coast-defence vessels. We have already noted this fact. We have seen how, especially to the lesser Powers, the turreted monitor appeared to offer an economical and effective form of naval force; and we have noted how, in America, the evolution proceeded in the opposite direction, viz. from coast-defence monitor to ocean-going turret ship. This differentiation prevailed for many years. It prevailed even in the British navy, in spite of its being in full opposition to the offensive principle on which that navy had always based its policy.

Later, although convinced that in any war involving this country and its colonies the chief combats must be fought in European waters, naval opinion saw the necessity for a type of ship designed primarily for the defence and attack of commerce: a speedy, lightly armed and protected type capable of overhauling and injuring a weaker, or of escaping from a more powerful enemy. The American War of ’62, in which no general sea action was fought, gave the impulse to the construction of the type which eventually became known as the cruiser. Vessels were built in ’63 expressly to overtake Confederate vessels and drive from the seas the Southern mercantile marine. These vessels were to annihilate the enemy’s commerce without being drawn themselves to take part in an engagement, unless in very favourable circumstances. Several such ships were built. The first, the Idaho, was a complete failure; the next attempt was little more successful; and those subsequently constructed, the Wampanoag class, the finest ships of the type which existed at the close of the war, which were designed for 17 knots and to carry sixteen 10- or 11-inch smooth-bore cast-iron guns on the broadside and a revolving 60-pounder rifle in the bows, suffered from miscalculations in design and from the weakness peculiar to long and heavily weighted timber-built ships. “These pioneers of the type,” says Brassey, “were followed, both in England and in France, by vessels believed by the builders of their respective countries to be better adapted for the work for which they were designed.”

At first England and France had built and appropriated small ironclads to this secondary service; in France the Belliqueuse, in England the Pallas, were designed to this end. But in ’66 the first ship of the cruiser type was built for the British navy: the Inconstant, of Sir Edward Reed’s design, an iron-built, fine-lined vessel with a speed of 16 knots and a large coal capacity. She was followed by the corvettes Active and Volage, and then, in ’73, by the Shah and Raleigh. Experience with the early cruisers showed the advantages of large displacement. “The greater number of the American corvettes had now been launched. A trial of one of them showed that the high hopes which had been entertained of their performance were fallacious. It now appeared no longer necessary that the English corvettes should possess such extraordinary power and speed, qualities which necessarily required very large displacements. The Admiralty, however, still believing in the wisdom of the policy which they had previously adopted, decided to follow a totally different course from that which all other navies had been compelled by financial considerations to follow. So far from diminishing the size of their ships, increased displacement was given to the new designs.”[174] Full sail power was still required, for the high-power steam engine used by the cruiser for fighting purposes was most uneconomical. The Raleigh, for instance, burned her six hundred tons of coal in less than 36 hours, at full speed.

But after the Raleigh came a slight reaction. With a view to economy a smaller type of vessel was designed, the smallest possible vessel which could be contrived which would possess a covered-in gun deck in combination with other features considered essential in a frigate class; the result was the Boadicea or the Bacchante class. In the late ’seventies size again increased, and the Iris and Mercury, unsheathed vessels of steel, with coal-protection for their water-line and extended watertight subdivision of the hull, were laid down.

From the unarmoured, unprotected cruiser was in time evolved, by the competition of units, the armoured cruiser. Russia led the way. Her General-Admiral, the first belted cruiser, was built to compete with the Raleigh and Boadicea. Then England designed the Shannon, partially belted and with protective deck and coal protection, to outmatch her. Eventually the cleavage came, and the cruisers were themselves divided into two or more classes, in accordance with their duties, size and fitness for the line of battle.

* * * * *