ualities concern primarily the naval architect and the marine
engineer. This is an error. Warships exist for war. Their powers,
being for the operations of war, are military necessities, the
appreciation of which, and the consequent qualities demanded, are
military questions. Only when these have been decided, upon military
reasons, begins the office of the technologist; namely, to produce the
qualities prescribed by the sea officer. An eminent British naval
architect used to say, "I hold that it is the part of the naval
officers to tell us just what qualities--speed, gun-power, armor, coal
endurance, etc.--are required in a ship to be built, and then leave it
to us to produce the ship." These words distinguish accurately and
summarily the functions of the military and the technical experts in
the development of navies. It is from the military standpoint, solely,
that this article is written.

The military function of a navy is to control the sea, so far as the
sea contributes to the maintenance of the war. The sea is the theatre
of naval war; it is the field in which the naval campaign is waged;
and, like other fields of military operations, it does not resemble a
blank sheet of paper, every point of which is equally important with
every other point. Like the land, the sea, as a military field, has
its important centres, and it is not controlled by spreading your
force, whatever its composition, evenly over an entire field of
operations, like butter over bread, but by occupying the centres with
aggregated forces--fleets or armies--ready to act in masses, in
various directions from the centres. This commonplace of warfare is
its first principle. It is called concentration, because the forces
are not spread out, but drawn together at the centres which for the
moment are most important.

Concentrated forces, therefore, are those upon which warfare depends
for efficient control, and for efficient energy in the operations of
war. They have two chief essential characteristics: force, which is
gained by concentration of numbers; and mobility, which is the ability
to carry the force rapidly, as well as effectively, from the centre to
any point of the outlying field where action, offensive or defensive,
becomes necessary. It is essential to keep in mind both these factors,
and to study them in their true mutual relations of priority, in order
and in importance,--force first, mobility second; for the force does
not exist for t