When the nineteenth century began, the ships that contended for the
control of the sea were, and for two centuries had been, sailing
ships with broadside batteries: the guns, that is, were distributed
along both sides from the bow to the stern on one, two, three, or
four decks. From the largest down, all were of this type until the
very smallest class was reached. In the latter, which could scarcely
be considered fighting ships, the gun power was at times concentrated
into a single piece, which swept from side to side round the horizon,
thus anticipating partially the modern turreted ironclad with its
concentrated revolving battery.
The arrangement of guns in broadside involved anomalies and
inconveniences which seem most singular when first noted. A ship in
chase of another, for instance, had no guns which threw straight ahead.
If it were wished to fire, in order to cripple the fleeing enemy,
it was necessary to deflect from the course; and in order to bring
most of the guns on one side into play the vessel had to swing round
nearly at right angles to the direction of pursuit. This, of course,
lost both time and ground. Broadside fire—the distribution of guns
in broadside—rests, however, upon an unchangeable condition, which
controls now as it did a century ago. Ships then were from three to
four times as long as they were broad; the proportion now is, length
from four to six times the breadth—or beam, as it is technically
called. Therefore, except in small vessels, where the concentration
of the whole weight that can be carried in battery gave but one piece
effective against a probable target, a full development of fire
required the utilization of the long side of the ship rather than of
its short cross-section. This is precisely analogous to the necessity
that an army has of deploying into line, from any order of march, in
order to develop its full musketry fire. The mechanical attainment of
the last century did not permit the construction of single guns that
would contain the weight of the whole battery of a big ship: but even
had it, guns are not wanted bigger than will penetrate their target
most effectively. When an ounce of lead will kill a man it is useless
to fire a pound. The limit of penetration once reached, it is numbers,
not size, that tell: and numbers could be had only by utilizing
the broadside. This condition remains operative now; but as modern
battle-ships present two or more kinds of target—the heavy armored
and that which is light armored, or unprotected—the application of
the principle in practice becomes more complicated. Batteries now are
necessarily less homogeneous than they once were, because targets vary
more.