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 , F. R. S., etc., etc. With Illustrations. London: John Murray. 1860. pp. xx., 444.
OUR readers are probably aware that the question of the causes of glacier formation and motion, cool as the subject may seem in itself, has demonstrated the existence of a great deal of latent heat among scientific men. In England, the so-called viscous theory of Professor J. D. Forbes held for a long while undisputed possession of the field. According to him, “ a glacier is an imperfect fluid, or viscous body, which is urged down slopes of a certain inclination by the mutual pressure of its parts.” With that impartial superciliousness to all foreign achievement which not seldom characterizes the British mind, the credit of all the results of observation and experiment on the glaciers was attributed to Professor Forbes, who seems to have accepted it with delightful complacency. But presently doubt, then unbelief and at last downright opposition began to show themselves. The leader of the revolt was Professor Tyndall, whose book is now before us. The controversy has begotten no little bitterness of feeling; but none is shown in Mr. Tyndall’s volume, which is throughout written in the truest spirit of science, — with the earnest frankness that becomes a seeker of truth, and the dignity that befits a lover of it.
Not content with any theoretic antagonism to the Forbes explanation of the phenomena, Mr. Tyndall devoted all the leisure of several years to an examination of them on the spot. At the risk of his life, he verified the previous observations of others and made new ones himself. At home, he made experiments upon the nature of ice, especially upon its capacity for regulation and the effect of pressure upon it. He satisfied himself that snow may be changed to ice by pressure, that crumbled ice may in like manner be restored to its original condition, and that solid ice may be forced to take any form desired. Under proper conditions, lamination may be produced by the same means. The result of his investigations is, that the glacier is a solid body, and that pressure answers all the requirements of the glacier-problem, and is the only thing that will.
The book is one of uncommon interest, and discusses many topics beside the glaciers, though nothing that is not in some way related to them. Mr. Tyndall does justice to former investigators, — especially to M. Rendu. who, though imperfectly supplied with demonstrated facts, theorized the phenomena with the happiest inspiration,— and to Agassiz, of whose important observations, establishing for the first time the fact of more rapid motion in the middle of the glacier, Professor Forbes had appropriated the credit. The style is remarkably agreeable, in description vivid, and in its scientific parts clear. Indeed, we do not know whether we have enjoyed the narrative or the science the most. Professor Tyndall has the uncommon gift of being able to write science so that the unscientific can understand it, without descending to the low level of science made easy. The Royal Institution may well congratulate itself on having in him a man every way qualified to succeed Faraday, whenever (and may it be long first!) his chair is vacant.