Entered according to Act of Congress, in the year 1863, by in the Clerk's Office of the District Court of the District of Massachusetts. UNIVERSITY PRESS: CAMBRIDGE. CONTENTS 1. Études sur les Glaciers. Par LOUIS AGASSIZ. 2. Essai sur les Glaciers et sur le Terrain Erratique du Bassin du Rhone. Par JEAN DE CHARPENTIER. 3. Occasional Papers on the Theory of Glaciers, now first collected and chronologically arranged. With a Pref- atory Note on the Recent Progress and Present Aspect of the Theory. By JAMES D. FORBES. 4. The Glaciers of the Alps. Being a Narrative of Excursions and Ascents, an Account of the Origin and Phenomena of Glaciers, and an Exposition of the Physi- cal Principles to which they are related. By JOHN TYN- DALL. 1. A Discourse on the Life, Character, and Policy of Count Cavour, delivered in the Hall of the New York Historical Society, February 20, 1862. By VINCENZO⚫ 1. Egyptian Chronicles, with a Harmony of Sacred and Egyptian Chronology, and an Appendix on Babylonian and Assyrian Antiquities. By WILLIAM PALMER. 2. An Historical Survey of the Astronomy of the An- cients. By the RIGHT HON. SIR GEORGE CORnewall 1. L'Année Littéraire et Dramatique, ou Revue Annu- elle des Principales Productions de la Littérature Fran- çaise, &c., &c. Par G. VAPEreau. 2. Revue de l'Année Religieuse, Philosophique et Lit- téraire, &c. son, late Professor of Moral Philosophy in the Univer- sity of Edinburgh. Compiled from Family Papers and other Sources, by his Daughter, MRS. GORDON. 2. The Works of PROFESSOR WILSON, of the Univer- sity of Edinburgh. Edited by his Son-in-Low, PROFES- NORTH AMERICAN REVIEW. No. CXCVIII. JANUARY, 1863. ART. I.-1. Études sur les Glaciers. Par LOUIS AGASSIZ. Neufchatel. 1840. 2. Essai sur les Glaciers et sur le Terrain Erratique du Bassin du Rhone. Par JEAN DE CHARPENTIER. 1841. 3. Occasional Papers on the Theory of Glaciers, now first collected and chronologically arranged. With a Prefatory Note on the Recent Progress and Present Aspect of the Theory. By JAMES D. FORBES, D. C. L., F. R. S., Professor of Natural Philosophy in the University of Edinburgh. Edinburgh: Adam and Charles Black. 1859. 8vo. pp. 278. 4. The Glaciers of the Alps. Being a Narrative of Excursions and Ascents, an Account of the Origin and Phenomena of Glaciers, and an Exposition of the Physical Principles to which they are related. By JOHN TYNDALL, F. R. S., Professor of Natural Philosophy in the Royal Institution of Great Britain, and in the Government School of Mines. With Illustrations. Boston: Ticknor and Fields. 1861. pp. 446. "THE speculations of the natural philosopher," says Sir John Herschel, "however remote they may for a time lead him from beaten tracks and every-day uses, being grounded in the realities of nature, have all of necessity a practical application." Students of natural philosophy are too often condemned as useless speculators by that large class of so-called practical and common-sense persons who see no value in any NO. 198. VOL. XCVI. 1 pursuit not directly productive of material advantage. Pure science is one thing, applied science another; and we must no more expect a single man to cultivate both, than that the judge having interpreted the law shall descend and execute the details of police duty. Some must perfect tools, while others apply them to daily use; and some must devote themselves to the study of those natural phenomena which make us acquainted with the causes whence proceed the effects upon which our worldly labors depend. It is easy enough to appreciate science when we see it applied to art; but enlightened philosophical liberality will acknowledge and encourage the science before the art is born. No branch of study will place us in closer connection with the workings of nature, or in a better position to observe how the most delicate physical elements combine to produce the most stupendous results, than that which concerns those vast masses of ice, the glaciers, which, descending from the snowfields of the higher Alps with slow but irresistible march into the lower valleys, overwhelming villages, mowing down forests, damming rivers, ploughing up the soil, and grinding, grooving, and polishing the rocks over which they pass, finally present the apparent anomaly of a mountain of perpetual ice surrounded by orchards and pastures and fields of grain. The appearance of the intensely interesting book of Professor Tyndall has induced us to present a brief review of the several glacial theories which have been put forth since 1840, with an exposition of the present state of the question, considered as a matter of physics. We say as a matter of physics, for as such the cause of glacier motion must be regarded; although the geologists were the first to enter this field of research, and the effects of glacial action, as seen in the modification of surface geology, certainly belong to that science. Of the geological agency of the glaciers in the past and present we do not propose to speak, but refer to the works of Charpentier and Agassiz. In the ordinary economy of nature, the water which descends from the clouds as rain is disposed of in three ways; first, by being absorbed into the soil; secondly, by evaporating into the air; and thirdly, by flowing off from the high |