se among us who are already
learned in the geology and palaeontology of our continent; but we do
mean to affirm, that, by the efficient aid which this work will be to
them, thousands and tens of thousands who have sought hitherto for
information on its great subjects, when seeking was literally "groping
in darkness," will be helped forward to a degree of knowledge respecting
the history and life of our globe which they could not otherwise have
attained.

_Elements of Military Art and History_: comprising the History and
Tactics of the Separate Arms, the Combination of the Arms, and the Minor
Operations of War. By EDWARD DE LA BARRE DUPARCQ, Captain of Engineers
in the Army of France, and Professor of the Military Art in the School
of Saint-Cyr. Translated and edited by BRIGADIER-GENERAL GEORGE W.
CULLUM, Chief of Staff of the General-in-Chief of the Armies of the
United States. 8vo. New York: D. Van Nostrand.

War has its science and its art. There is a domain of general
_principles_, which have their application in all the active operations
of war; and military _science_ is but the sum of these principles in
their theory and practice. The _art_ of war deals more directly with
the details and practical direction of military affairs, and abounds in
_rules_ of action, organization, and administration. Military science
and art are equally the results of experience in war. Principles of
strategy have grown out of the exercise of the highest military mind in
weighing the general features of campaigns, and from the perceptive and
logical recognition of those elements essential to success. The art
of war has grown up as a body of practices, traditions, and rules,
naturally resulting from the immense sum of experience in military life
and action among all nations. It is, indeed, so inwoven with military
history that the two should be studied in connection. Military art is
more mature than military science; and in war, as in the practice of
other professions and trades, definite and empirical rules for daily
guidance, based mainly on practice, serve almost to exclude science and
to keep it unprogressive. When, however, a Napoleonic mind becomes truly
imbued with vital military principles, its most successful strokes
may result from a bold disregard of rules under the lead of higher
intelligence. But as military science is very imperfect, and as
Hannibals, Fredericks, and Napoleons are not every-day products, it
behooves less