writing on an extensive
scale; and that the nature of their occupation has been such that
continuous application of the kind needed for thinking out principles
and expounding them in books, has only recently been possible.

Most of the few existing books on naval strategy deal with it
historically, by describing and explaining the naval campaigns
of the past and such land campaigns as illustrate principles that
apply to sea and land alike. Perhaps the best books are those of
Darrieus and Mahan.

Until about fifty years ago, it was only by experience in actual
war, supplemented by laborious study of the campaigns of the great
commanders, and the reading of books on strategy which pointed
out and expounded the principles involved in them, that one could
arrive at any clear idea of strategy.

But wars have fortunately been so infrequent, the information about
them has often been so conflicting, and so many results have been
due to chance, that, in default of experience, the mere reading
of books did not lead to very satisfactory results, except in the
case of geniuses; and therefore war problems and war games were
devised, in which the various factors of material and personnel
were represented, and made as true to life as possible.

The _tactical_ games resulting, which naval strategists now play,
employ models of the various craft used in war, such as battleships,
submarines, etc., and are governed by rules that regulate the movements
of those craft on a sort of big chess-board, several feet square, that
represents an area of water several miles square. The _strategic_
games and problems are based on principles similar to those on which
the tactical games are based, in the sense that actual operations are
carried on in miniature; but naturally, the strategical operations
cover several hundred miles, and sometimes thousands. The aim of
both the tactical and the strategic games is to determine as closely
as possible the laws that decide victory or defeat; and therefore,
for any country, the material, personnel and operations it should
employ. Naturally the results obtained are not quite so convincing
as those of actual war or battle; but they are more convincing
than can be attained in any other way, as yet devised, especially
as many of the operations of the game-board that turn out well in
games are tried out afterward by the fleet in peace maneuvers.
War games and problems may be compared to the drawings that an
ar