her parts are fastened together with the utmost rigidity; while
the parts of an army are men, who are held together by no means
whatever except that which discipline gives, and the men themselves
are far from rigid. In the nature of things it is impossible that
an army should be directed as perfectly as a ship. The rudder of a
ship is a mechanical appliance that can be depended upon to control
the direction of the ship absolutely, while an army has no such
a thing as a rudder, or anything to take its place. Again, the
rudder is only a few hundred feet from the helmsman, and the
communication between them, including the steering-engine itself,
is a strong reliable mechanism that has no counterpart in the army.

The control of the main engines of a ship is almost as absolute
as the control of the rudder; and the main engines are not only
much more powerful than the legs of soldiers, but they act together
in much greater harmony.

_Inherent Power of a Battleship_.--Possibly the declaration may be
accepted now that a battleship of 30,000 tons, such as the navies
are building now, with, say, twelve 14-inch guns is a greater example
of power, under the absolute direction and control than anything
else existing; and that the main reason is the concentration of
a tremendous amount of mechanical energy in a very small space,
all made available by certain properties of water. Nothing like
a ship can be made to run on shore; but if an automobile could
be constructed, carrying twelve 14-inch guns, twenty-two 5-inch
guns, and four torpedo-tubes, of the size of the _Pennsylvania_,
and with her armor, able to run over the land in any direction at
20 knots, propelled by engines of 31,000 horse-power, it could
whip an army of a million men just as quickly as it could get hold