ase the establishment of a blockade of
this character is for many purposes practically tantamount to securing
the command of the sea to the blockader so long as the blockade can be
maintained. Such a situation, however, can very rarely arise. There are
very few instances of it in naval history, and there are likely to be
fewer in the future than there have been in the past. The closest
blockade ever established and maintained was that of Brest by Cornwallis
from 1803 to 1805, when Napoleon was projecting the invasion of
England. Yet it would be too much to say that during those strenuous
years Ganteaume never could have got out, had he been so minded, and it
is not to be forgotten that for some time during the crisis of the
campaign he was forbidden by Napoleon to make the attempt. Moreover,
such a situation, even when it does arise, amounts at best to a
stalemate, not to a checkmate. It leaves the enemy's fleet "a fleet in
being," immobilized and wiped off the board for the moment, but
nevertheless so operating as to immobilize the blockading fleet in so
far as the chief effort of the latter must be concentrated on
maintaining the blockade.

It is necessary to dwell at some length on this conception of "a fleet
in being." Admiral Mahan, the great historian of sea power--whose high
authority all students of naval warfare will readily acknowledge and
rarely attempt to dispute--speaks of it in his _Life of Nelson_ as a
doctrine or opinion which "has received extreme expression ... and
apparently undergone extreme misconception." On the other hand, Admiral
Sir Cyprian Bridge tells us in the _Encyclopaedia Britannica_ (_s.v._
"Sea-Power") that "the principle of the 'fleet in being' lies at the
bottom of all sound strategy." Of a principle which, according to one
high authority, lies at the bottom of all sound strategy, and according
to another has received extreme expression and undergone misconception
equally extreme, it is plainly essential that a true conception should
be obtained before it can be applied to the elucidation of any of the
problems of naval warfare. Now what is this much-debated principle? It
is best to go to the fountain-head for its elucidation. The phrase "a
fleet in being" was first used by Arthur Herbert, Earl of Torrington, in
his defence before the Court Martial which tried and acquitted him for
his conduct of the naval campaign of 1690, and especially of the Battle
of Beachy Head, which was the lea