IXX PEOCEEDIXGS OF THE GEOLOGICAL SOCLETY. 



Scandinavia and Iceland from which Baron Waltershausen gathers 

 confirmation for his theory ; but from these, and from the glacial 

 phenomena described for various tracts throughout Europe, he 

 concludes that the total area to which they refer is but a small frac- 

 tion, say six per cent., of the whole of that quarter of the globe ; 

 that the glaciers were never more than local streams, due chiefly to 

 elevation of the land, and that the effects of the drift-ice, or bergs 

 and floes, might be produced by a moderately reduced mean winter 

 temperature, and require for their explanation no general reduction 

 and no degree of cold incompatible with Fourier's theory of heat. 



Taken in a general sense, these views gaiu in probability what 

 they lose in originality, when we look back to Mr. Godwin- Austen's 

 account of the superficial accumulations of our south-western coasts, 

 and fluud him stating that he can only explain the facts by an eleva- 

 tion of great amount, such as would place the ivTiole of the higher 

 portions of this country in regions of excessive cold* — nay, more, that 

 whilst disbeheving iu the " Glacial period", as propounded by Agassiz, 

 he would infer that a great elevation had at the same time affected 

 a large part of Europe, and that the Alps must at one time have 

 attained an altitude equal to that of the Himalayas. 



The Society will not have forgotten that, in his elaborate and phi- 

 losophical paper " On Changes of Climate," our former President, Mr. 

 Hopkins, examined at some length the hypothesis of producing by 

 local elevation of the land a great degree of cold to account for the 

 former extension of glaciers in the Alps and jSTorth Wales. He was 

 inclined to consider it untenable, first, on account of his estimate 

 that an elevation of at least 6000 feet would be required in the former, 

 and 7000 or 8000 feet in the latter case ; and secondly, because " aU 

 geological experience assures us that no such moimtain-range exists 

 without numerous dislocations and other phenomena of elevation 

 having determinate relations to the elevated tract." After a careful 

 review of his reasoning, I cannot but think that the objections to 

 such a view of the causation of a glacial temperature are in great 

 part removed by the detailed comparison of observed facts made by 

 von "Waltershausen leading to the requirement of no excessive 

 alteration of altitude ; whilst, on the second score, that geologist 

 must indeed be extravagant in his demands for evidence of mecha- 

 nical action, who is unsatisfied with the " accidentation" of the Alps, 

 or with the strange medley of lines of fault, dyke, and fold so won- 

 derfully exhibited in Prof. Kamsay's map of the Snowdonian country. 

 Nor is it allowable to treat the question as if the elevation of the 

 mass of land in these districts, with its subsequent depression, were 

 a new kind of requirement, when for many years past we have been 

 familiarized with the proofs of the upheaval of these very moun- 

 tain-tracts to considerable altitudes, and at periods separated by no 

 great interval from that under discussion. 



Geology of Savoy. — IS'ot only geologists, but all Alpine tourists 

 gifted with any power or desire of observation, wiU be thankful to 

 M. Alphonse Eavre for the labour of love which he has just com- 

 * Quart. Journ. Geol. Soc. 1851. p. 130. 



