wer of the flotilla has greatly increased. Its real and
moral effect against transports must certainly be greater than ever, and
the power of squadrons to break a flotilla blockade is more restricted.
Mines, again, tell almost entirely in favour of defence, so much so indeed
as to render a rapid _coup de main_ against any important port almost an
impossibility. In the absence of all experience it is to such theoretical
considerations we must turn for light.

Theoretically stated, the success of our old system of defence depended on
four relations. Firstly, there is the relation between the rapidity with
which an invasion force could be mobilised and embarked, and the rapidity
with which restlessness in foreign ports and _places d'armes_ could be
reported; that is to say, the chance of surprise and evasion are as the
speed of preparation to the speed of intelligence.

Secondly, there is the relation of the speed of convoys to the speed of
cruisers and flotilla; that is to say, our ability to get contact with a
convoy after it has put to sea and before the expedition can be disembarked
is as the speed of our cruisers and flotilla to the speed of the convoy.

Thirdly, there is the relation between the destructive power of modern
cruisers and flotillas against a convoy unescorted or weakly escorted and
the corresponding power in sailing days.

Fourthly, there is the relation between the speed of convoys and the speed
of battle-squadrons, which is of importance where the enemy's transports
are likely to be strongly escorted. On this relation depends the facility
with which the battle-squadron covering our mobile defence can secure an
interior position from which it may strike either the enemy's
battle-squadron if it moves or his convoy before it can complete its
passage and effect the landing.

All these relations appear to have been modified by modern developments in
favour of the defence. In the first ratio, that of speed of mobilisation to
speed of intelligence, it is obviously so. Although military mobilisation
may be still relatively as rapid as the mobilisation of fleets, yet
intelligence has outstripped both. This is true both for gaining and for
conveying intelligence. Preparations for oversea invasion were never easy
to conceal, owing to the disturbance of the flow of shipping that they
caused. Elaborate precautions were taken to prevent commercial leakage of
intelligence, but they never entirely succeeded. Yet f