the enemy's main body;
but, until then, all that the department and fleet would know would
be that a large hostile force had left Europe. They would not know
its size or destination.

Clearly, the first thing we should need would be information. To
get this after war has broken out, the only means is scouts.

_Scouting and Screening_.--Scouts are needed by every navy; but
they are most needed by a navy that has a very long coast-line to
protect. If the great commercial centres and the positions that
an enemy would desire for advanced bases along the coast, have
local defenses adequate to keep off a hostile fleet for, say, two
weeks, the urgency of scouts is not quite so absolute; since, even
if the hostile fleet evades our scouts and our fleet, and reaches
our shores, our fleet will have two weeks in which to get to the
place attacked. But if the coast is not only long but also unguarded
by shore defenses, the urgency is of the highest order.

If we knew our fleet to be the weaker, but if we did not believe it
to be so much the weaker as to force it to seek safety in flight,
our natural plan would be that of Napoleon's in Italy in 1797--to
keep our force together, and to hurl it against detached parts
of the enemy's force, whenever possible. This plan might not be
difficult of execution, if the enemy were accompanied by his train
of auxiliary and supply ships; since such ships are vulnerable to
almost any kind of attack, have almost no means of defense whatever,
and therefore require that a part of the fighting force of the
main body be detached to guard them. Whether the enemy would have
his train quite close to him, or a day's steaming behind, say 240
miles, we should not, of course, know.

How could we ascertain?

If the enemy came along with no scouts ahead, and if we happened
to have some scouts located along his line of advance, these scouts
faster than his ships, and so heavily armed as not to fear to venture
near, our scouts might proceed along the flank of the enemy in
daylight, pass along his rear, go entirely around him, and then
report to our commander-in-chief by wireless telegraph exactly what
craft of all kinds comprised the force, what formation they were
in, the direction in which they were steaming, and the speed. Such
information would be highly appreciated by our commander-in-chief,
as it would enable him to decide what he had better do. If, for
instance, the scouts reported that the enemy fl