So far, then, the principles on which our naval supremacy was built up are clear. For the enemies with whom we had to deal Anson's system was admirably conceived. Both Spain and France held the communication theory so strongly, that they were content to count as success the power of continually disturbing our control without any real attempt to secure it for themselves. To defeat such a policy Anson's constitution and the strategy it connoted were thoroughly well adapted and easy to work. But it by no means follows that his doctrine is the last word. Even in his own time complications had begun to develop which tended to confuse the precision of his system. By the culminating year of Trafalgar there
were indications that it was getting worn out, while the new methods and material used by the Americans in 1812 made a serious rent in it. The disturbances then inaugurated have continued to develop, and it is necessary to consider how seriously they have confused the problem of fleet constitution.
Firstly, there is the general recognition, always patent to ourselves, that by far the most drastic, economical, and effective way of securing control is to destroy the enemy's means of interfering with it. In our own service this "overthrow" idea always tended to assert itself so strongly, that occasionally the means became for a time more important than the end; that is to say, circumstances were such that on occasions it was considered advisable to sacrifice the exercise of control for a time in order quickly and permanently to deprive the enemy of all means of interference. When there was reasonable hope of the enemy risking a decision this consideration tended to override all others; but when, as in Nelson's case in the Mediterranean, the hope was small, the exercise of control tended to take the paramount place.
The second complexity arose from the fact that however strong might be our battleship cover, it is impossible for it absolutely to secure cruiser control from disturbance by sporadic attack. Isolated heavy ships, taking advantage of the chances of the sea, could elude even the strictest blockade, and one such ship, if she succeeded in getting upon a line of communication, might paralyse the operations of a number of weaker units. They must either run or concentrate, and in either case the control was broken. If it were a squadron of heavy ships that caused the disturbance, the practice was to detach against it a division of the covering battle-fleet. But it was obviously highly inconvenient and contrary to the whole idea on which the constitution of the fleet was based to allow every slight danger to cruiser control to loosen the cohesion of the main fleet.
It was necessary, then, to give cruiser lines some power of
resistance. This necessity once admitted, there seemed no point at which you could stop increasing the fighting power of your cruisers, and sooner or later, unless some means of checking the process were found, the distinction between cruisers and battleships would practically disappear. Such a means was found in what may be called the "Intermediate" ship. Frigates did indeed continue to increase in size and fighting power throughout the remainder of the sailing era, but it was not only in this manner that the power of resistance was gained. The evil results of the movement were checked by the introduction of a supporting ship, midway between frigates and true ships-of-the-line. Sometimes classed as a battleship, and taking her place in the line, the 50-gun ship came to be essentially a type for stiffening cruiser squadrons. They most commonly appear as the flagships of cruiser commodores, or stationed in terminal waters or at focal points where sporadic raids were likely to fall and be most destructive. The strategical effect of the presence of such a vessel in a cruiser line was to give the whole line in some degree the strength of the intermediate ship; for any hostile cruiser endeavouring to disturb the line was liable to have to deal with the supporting ship, while if a frigate and a 50-gun ship got together they were a match even for a small ship-of-the-line.
In sailing days, of course, this power of the supporting ship was weak owing to the imperfection of the means of distant communication between ships at sea and the non-existence of such means beyond extreme range of vision. But as wireless telegraphy develops it is not unreasonable to expect that the strategic value of the supporting or intermediate ship will be found greater than it ever was in sailing days, and that for dealing with sporadic disturbance the tendency will be for a cruiser line to approximate more and more in power of resistance to that of its strongest unit.
For fleet service a cruiser's power of resistance was hardly less valuable; for though we speak of fleet cruisers as the eyes
of the fleet, their purpose is almost equally to blindfold the enemy. Their duty is not only to disclose the movements of the enemy, but also to act as a screen to conceal our own. The point was specially well marked in the blockades, where the old 50-gun ships are almost always found with the inshore cruiser squadron, preventing that squadron being forced by inquisitive frigates. Important as this power of resistance in the screen was in the old days, it is tenfold more important now, and the consequent difficulty of keeping cruisers distinct from battleships is greater than ever. The reason for this is best considered under the third and most serious cause of complexity.
The third cause is the acquisition by the flotilla of battle power. It is a feature of naval warfare that is entirely new.[10] For all practical purposes it was unknown until the full development of the mobile torpedo. It is true that the fireship as originally conceived was regarded as having something of the same power. During the Dutch wars—the heyday of its vogue—its assigned power was on some occasions actually realised, as in the burning of Lord Sandwich's flagship at the battle of Solebay, and the destruction of the Spanish-Dutch fleet at Palermo by Duquesne. But as the "nimbleness"