Dufour, "admit of no answers. Circumstances, which are always different, must decide in each particular case that arises. Here is the place for a general to show his ability. The military art would not be so difficult in practice, and those who have become so distinguished in it would not have acquired their renown, had it been a thing of invariable rules. To be really a great general, a man must have great tact and discernment in order to adopt the best plan in each case as it presents itself; he must have a ready coup d'œil, so as to do the right thing at the right time and place; for what is excellent one day may be very injurious the next. The plans of a great captain seem like inspirations, so rapid are the operations of the mind from which they proceed: notwithstanding this, everything is taken into account and weighed; each circumstance is appreciated and properly estimated; objects which escape entirely the observation of ordinary minds may to him seem so important as to become the principal means of inducing him to pursue a particular course. As a necessary consequence, a deliberative council if a poor director of the operations of a campaign. As another consequence, no mere theorizer can be a great general."
Battles, on which the fortune of the campaign must turn at last, receive a large share of attention. The decision of the question as to when they shall be fought, though sometimes admitting of no choice, is more often, with a skilful general, a matter of pure calculation, depending upon fixed principles, which General Dufour recites in a few brief, but suggestive sentences. His directions for the disposition and manœuvres of the forces in both offensive and defensive battles are quite complete, though the thousand varying circumstances by which these may be modified, and which render it impossible for one battle to be a copy of another, can only be hinted at. Among the elements of a battle here considered are the disposition of the forces, the manner of bringing on and conducting the engagement, the manœvres to change position on the field, bringing on reinforcements, seizing all advantages that may offer, and the manner of conducting pursuit or retreat. The attack and defence of mountains and rivers, of redoubts, houses, and villages, covering a siege, infantry, cavalry, and artillery combats and reconnoissances, each involve special principles, and ore treated separately. In the course of the article on battles, some general observations are introduced on conducting manœuvres so as to insure promptness, security, and precision. The conduct of topographical reconnoissances is well explained by means of a map of a supposed district of country, with marked features, which is to be examined. On this the course of the reconnoitring party, as it goes over the whole, is traced step by step, and fully explained in the letter-press. In the concluding chapter the author treats of convoys, ambuscades, advance posts, the laying-out of camps, and giving rest to troops.
Such are the outlines of a subject which General Dufour has handled in a masterly manner. His maxims are practical in their bearing, they commend themselves to our common sense as sound in principle, and are such as have received the indorsement of the best authorities. His style is clear and comprehensive; nothing superfluous is inserted, nothing need be added to make the subject more clear. The illustrations, which are given wherever they are needed, are simple and clear; the explanations are sufficient. This work will be a valuable manual to soldiers, and students will find it an excellent text-book. We hail it as an important addition to our growing military literature.
The student of Physical Geography must not expect to find in this massive book a systematic exposition of the science in the manner of Guyot and the French and German geographers; nor must he expect to see worked out on its pages the elaborate application of Geography to History, such as one day will be done, and such as was attempted, though with results of varied value and certainty, by the eloquent and plausible Buckle; but he will find an unexpected development of man's dominion over the world he inhabits. Mr. Marsh takes his readers very much by surprise; for few are aware, we apprehend, that in the course of his wan-
