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 resisting body; and
the power of a moving ship is due wholly to the mechanical energy
of the burning coal within its furnaces.