attleships, cruisers, and flotilla has so long dominated naval thought
that we have come to regard it as normal, and even essential. It may be so,
but such a classification has been by no means constant. Other ideas of
fleet constitution have not only existed, but have stood the test of war
for long periods, and it is unscientific and unsafe to ignore such facts if
we wish to arrive at sound doctrine.

The truth is, that the classes of ships which constitute a fleet are, or
ought to be, the expression in material of the strategical and tactical
ideas that prevail at any given time, and consequently they have varied not
only with the ideas, but also with the material in vogue. It may also be
said more broadly that they have varied with the theory of war, by which
more or less consciously naval thought was dominated. It is true that few
ages have formulated a theory of war, or even been clearly aware of its
influence; but nevertheless such theories have always existed, and even in
their most nebulous and intangible shapes seem to have exerted an
ascertainable influence on the constitution of fleets.

Going back to the dawn of modern times, we note that at the opening of the
sixteenth century, when galley warfare reached its culmination, the
constitution was threefold, bearing a superficial analogy to that which we
have come to regard as normal. There were the galeasses and heavy galleys
corresponding to our battleships, light galleys corresponding to our
cruisers, while the flotilla was represented by the small "frigates,"
"brigantines," and similar craft, which had no slave gang for propulsion,
but were rowed by the fighting crew. Such armed sailing ships as then
existed were regarded as auxiliaries, and formed a category apart, as
fireships and bomb-vessels did in the sailing period, and as mine-layers do
now. But the parallel must not be overstrained. The distinction of function
between the two classes of galleys was not so strongly marked as that
between the lighter craft and the galleys; that is to say, the scientific
differentiation between battleships and cruisers had not yet been so firmly
developed as it was destined to become in later times, and the smaller
galleys habitually took their place in the fighting line.

With the rise of the sailing vessel as the typical ship-of-war an entirely
new constitution made its appearance. The dominating classification became
twofold. It was a classification into vessels of s