Under the first head, we have much interesting matter concerning peat and coral formations, coral reefs and their origin, illustrated with figures.

Under the head of Water as an Agent, some plates are given, new to the general reader, of the remarkable canons of the Colorado, which so well illustrate the powerful agency of this element in wearing away for itself deep channels in the strata.  Under the same head is an interesting essay upon Glaciers, with figures, one of which is a reduced copy of a sketch in Agassiz’s great work, representing the Glacier of Zermatt, in the Monte-Rosa region.

Under the head of Heat as an Agent, we have, as might be expected, interesting and valuable matter upon volcanic phenomena, and those of metamorphism.

We have thus briefly passed in review the contents of the work, and without criticism, too, for we would scarcely have a sentence in the book altered or omitted.  Yet we do not always concur in all the views expressed or implied by the author.  For instance, we consider the evidence of the Jurassic age of the Ichnolitic strata of the sandstone of the Connecticut River too strong to allow of their being any longer classed among the Triassic.  We certainly differ from him in much that is said upon the subject of Man, as of one species.  Yet we do not care to dwell upon these points, especially the latter.  Our author will not expect to find all readers agreeing with him upon such mooted questions.

We do not think that we overestimate the value of this work, when we express our belief that its publication will mark an era in our geological progress.  By this we do not mean to imply that its character is such as to be of great service to those 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.