Nelson certainly shared Kempenfelt's views as to the possibilities of an inferior fleet kept actively in being. "As to our fleet," he wrote from the Mediterranean in 1796, "under such a commander-in-chief as Sir John Jervis nobody has any fear ... We are now twenty-two sail of the line. The combined fleet will not be above thirty-five.... I will venture my life Sir John Jervis defeats them. I do not mean by a regular battle, but by the skill of our admiral and the activity and spirit of our officers and seamen. This country is the most favourable possible for that skill with an inferior fleet; for the winds are so variable, that some one time in twenty-four hours you must be able to attack a part of a large fleet, and the other will be becalmed or have a contrary wind. Therefore I hope the Government will not be alarmed for our safety." Such a conception of the defensive may indeed be said to have become current in the British service. It was part of the reasoning which in 1805, after Villeneuve's escape from the Mediterranean, decided Sir John Orde to fall back on Ushant instead of entering the Straits. "I dare believe," he wrote, "Lord Nelson will be found in condition with his twelve of the line and numerous frigates to act on the defensive without loss and even to hang on to the skirts of the enemy's fleet should it attempt any material service, especially when encumbered with troops." In all this consideration of the potentialities of "a fleet in being" operating defensively it must never be forgotten that we are dealing with its possibilities in relation to a general command of the sea--to its general power of holding such command in dispute, as Torrington used it. Its power of preventing a particular operation, such as oversea invasion, is another matter, which will always depend upon the local conditions. If the "fleet in being" can be contained in such a way that it is impossible for it to reach the invading line of passage, it will be no bar to invasion. In 1690, so far as Torrington's fleet was concerned, the French, had they been so minded, might have made a descent, say, at Portsmouth while Torrington was at the Nore. But Torrington's fleet was not the only factor. His retreat forced Tourville to leave behind him unfought the squadrons of Shovel and Killigrew, and so far as commanding a line of invasion passage was concerned Tourville was himself as well contained as Torrington. The conditions of naval defence against invasion are in fact so complex compared with those of general naval defence that they must be treated later as a special branch of the subject.