a formal vote, deposited as a voucher with the Society of Natural Sciences at Neufchâtel, and was printed by that society in 1883. This paper contained the following contributions to the subject: 1. The sloping of the terminal beds of glaciers toward their interior, and their origin as closed-up crevasses. 2. The laminated structure or blue bands of glacier-ice. 3. The cause of the fan-shaped disposition of crevasses. 4. The more rapid motion of the glacier's center than of the sides. 5. The more rapid motion of the top than the bottom of the glacier. 6. The movement of glaciers which takes place by means of a molecular displacement, whence results the plasticity of the glacier. Later, he added the law of the formation of transverse crevasses in a plane perpendicular to the steepest slope of the glacier. With rare modesty Guyot never took part in the fierce discussions caused by the claim laid by others to his own discoveries, contenting himself with a simple statement of the facts published long afterward in his memoir on Agassiz.
In 1839 Guyot accepted a call to the Academy of Neufchâtel, where his friend Agassiz was then settled, and there he remained till his removal to America in 1848. His chair was that of History and Physical Geography, and he regarded the years of his work there as the period of his greatest intellectual activity. During this time he gave much attention to his glacial work, taking up the geological side of the question, the erratic blocks and ancient extension of the glaciers, and devoting to this work "absolutely single-handed, seven laborious summers, from 1840 to 1847." This gigantic undertaking was brought to a successful conclusion, though the results were but partially published, inasmuch as the "Système Glaciaire," by Agassiz, Guyot, and Desor, never went further than the first volume (Paris, 1847). Guyot's collection of five thousand erratic rocks, illustrating eleven erratic basins, now fills a room in the Princeton Museum, a monument of incredibly pains-taking labor.
The political disturbances of 1848 induced Guyot to follow his friend Agassiz to America, and he lived for some time at Cambridge, Massachusetts. He first attracted public attention by the remarkable series of lectures afterward published in the well-known book "Earth and Man." These lectures were the starting-point of a great reform in the historical and geographical teaching of this country. For six years he was engaged by the Board of Education of Massachusetts as a lecturer to the normal schools on geography and the methods of teaching it, and after he came to Princeton he followed up the work there commenced by preparing a series of geographical text-books and large maps. To use the words of a recent writer in "Science" with regard to these books: "It is not too much to say that they revolutionized the methods of teaching geography. Every series of geographies which has since appeared shows the influence of Guyot." He threw aside the old routine methods, and brought the pupil face to face with Na-
