groups of powerful cruisers, and even battleship divisions, to meet them and reinforce their escorts.  Outward-bound convoys had their escorts similarly strengthened till they were clear of the danger zone.  The system was in regular use both for home and colonial areas.  In no sense did it constitute a patrol of the routes.  It was in practice and conception a system of outposts, which at seasons of special risk amounted to an extension of the defended areas combining with a reinforcement of the convoy escorts.  Focal points of lesser importance, such as Capes Finisterre and St. Vincent, were similarly held by one or two powerful cruisers, and if necessary by a squadron.

As has been already explained, owing to the peculiar conditions of the sea and the common nature of maritime communications, these dispositions were adopted as well for attack as defence, and the fertile areas, for the defence of which a frigate captain was sent “on a cruise,” were always liable to bring him rich reward.  His mission of defence carried with it the best opportunities for attack.

In the full development of the system patrol lines did exist, but not for the great routes.  They were established to link up adjacent defended areas and as a more scientific organisation of the cruiser outposts.  In 1805 the Gibraltar and the home areas were thus connected by a patrol line which stretched from Cape St. Vincent through the Finisterre focal area to Cape Clear, with a branch extending to the strategical centre off Ushant.  The new system was introduced at a time when we had reason to expect that the French and Spanish fleets were to be devoted entirely to operations in small raiding squadrons against our trade and colonies.  Special provision was therefore necessary to locate any such squadrons that might elude the regular blockades, and to ensure that they should be adequately pursued.  The new lines were in fact intelligence patrols primarily, though they were also regarded as the only means of protecting efficiently the southern trade-route where it was flanked by French and Spanish ports.[24]

[24] It should be said that Cornwallis did not regard this system as new except for the extension from Finisterre to St. Vincent, which Nelson advised.  In acknowledging the order from Ushant he wrote, “The instructions ... are nearly the same as have generally been given.  I can therefore only guess why a copy of the order was sent to me.”—­Admiralty, In-Letters, 129, 28 September 1805.

The whole system, it will be observed, though not conflicting with the main object of bringing the enemy’s fleets to action, did entail an expenditure of force and deflecting preoccupations such as are unknown in land warfare.  Large numbers of cruisers had to be employed otherwise than as the eyes of the battle-squadrons, while the coming and going of convoys produced periodical oscillations in the general distribution.