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.

The doctrine of the “Fleet in being” as formulated and practised by Torrington and developed by Kempenfelt goes no further than this, that where the enemy regards the general command of a sea area as necessary to his offensive purposes, you may be able to prevent his gaining such command by using your fleet defensively, refusing what Nelson called a regular battle, and seizing every opportunity for a counterstroke.  To use it as it was used by the French in the case of Tourville’s famous deterrent cruise, where the whole object of the French was offensive and could not be obtained except by offence, is quite another thing.

It is indeed difficult to understand the admiration with which his campagne au large has been treated in France.  He kept the sea off the mouth of the Channel for fifty days in the summer of 1691, and for forty of those days our Channel fleet was making no systematic effort to seek him out.  He had been sent to sea in hope of intercepting our great “Smyrna convoy,” which was then the backbone of our oversea trade.  Russell with the British main fleet simply took positions to cover its approach until it was safe, knowing presumably that Tourville must come to him if he wished to accomplish his purpose.  When the convoy was safe Russell proceeded off Ushant, that is, between the enemy and his base.  Tourville’s communications were thus cut, his line of retreat threatened, and he seized the first opportunity to elude Russell and to return into port.  Beyond taking a few ships from one of the West India convoys, he accomplished nothing.  The central French offensive in Ireland was broken at the battle of the Boyne, and the prestige of England at sea was restored.  It is true our trade suffered in the North Sea, but this was not directly due to the concentration which Tourville’s cruise forced upon us, but rather to the failure of the Dutch—­apparently by a misunderstanding-to provide for an effective blockade of Dunkirk.

To British eyes it will seem that the heresy which was latent in Tourville’s instructions was a seed that choked all the finer aspirations of the French navy.  In 1691 the plan of his cruise may possibly be defended as sufficiently aggressive, since, seeing how unstable was William’s new throne, a resounding blow at British trade, combined with an expected victory in Ireland, might have been enough to upset it.  But afterwards the idea was stretched to occasions it would not fit.  It seems to have