wer
is required.

In fact, apart from its usefulness in furnishing auxiliaries, it
seems certain that the merchant service has been an element of
_weakness_. The need for navies arose from the weakness of merchant
ships and the corresponding necessity for assuring them safe voyages
and proper treatment even in time of peace; while in time of war
they have always been an anxious care, and have needed and received
the protection of fighting ships that have been taken away from
the fleet to act as convoys.

If commercial sea power was not the power meant by Mahan, then he
must have meant naval power. And if one reads the pages of history
with patient discrimination, the conviction must grow on him that
what really constituted the sea power which had so great an influence
on history, was _naval_ power; not the power of simply ships upon
the sea, but the power of a navy composed of ships able to fight,
manned by men trained to fight, under the command of captains skilled
to fight, and led by admirals determined to fight. Trafalgar was
not won by the merchant service; nor Mobile, Manila, or Tsushima.

If sea power be essentially naval power, it may be interesting to
inquire: In what does naval power consist and what are its principal
characteristics?

If one looks at a fleet of war-ships on the sea, he will be impressed
consciously or unconsciously with the idea of power. If he is impressed
consciously, he will see that the fleet represents power in the
broadest sense--power active and power passive; power to do and
power to endure; power to exert force and power to resist it.

If he goes further and analyzes the reasons for this impression
of power, he will see that it is not merely a mental suggestion,
but a realization of the actual existence of tremendous mechanical
power, under complete direction and control.

In mechanics we get a definition of power, which, like all definitions
in mechanics, is clear, definite, and correct. In mechanics, power
is the rate at which mechanical work is performed. It is ability
to do something in a certain definite time.

Now this definition gives us a clear idea of the way in which a
navy directly represents power, because the power which a navy
exerts is, primarily, mechanical; and any other power which it
exerts is secondary and derived wholly from its mechanical power.
The power of a gun is due wholly to the mechanical energy of its
projectile, which enables it to penetrate a