2C0 R. Chambers, Esq., on Glacial Phenomena 



The general glaciation of which we see traces in Scotland, 

 finds a still more unequivocal parallel in the northern part 

 of the American Continent. It is well known that there are 

 proofs all over Canada, and to a point far south in the United 

 States, as well as around Lakes Huron and Superior, of an 

 abrading agent for the most part from the north-west.* 

 Mountains of 2000 feet in height bear on their sides and 

 tops striation in that direction ; while to the north-westward, 

 no mountains of greater elevation to serve as gathering- 

 places for glaciers can be pointed out. Scandinavia, indeed, 

 would be in precisely the same circumstances as North 

 America in respect of these phenomena, if there were no 

 such lofty chain as the Dovre-Field to variegate its surface 

 — hence that plateau may be presumed to be quite indifferent 

 in the case, except as a proof of the grandeur of the agent 

 which could over-ride such elevations. 



Speculations on the Causes of the More General Glaciation. 

 When the phenomena of ancient glacial action in the 

 region of the Alps were first observed by Messrs Charpen- 

 tier, Venetz, and Agassiz, it was thought that the abrasion 

 of Scandinavia, which had been described some years before 

 and attributed to floods, might be accounted for by an ex- 

 tension of the polar ice over that region, and its movement 

 southwards, under the influence of a principle of dilatation, 

 supposed to reside within the glacier itself, and believed to 

 be dependent on the infiltration of water into chinks and its 

 subsequent freezing. This doctrine of dilatation has been, 

 as is well known, very generally abandoned, in consequence 

 of the demonstrations brought by Professor James Forbes in 

 favour of his proposition, that " a glacier is an imperfect 

 fluid, or a viscous body, which is urged down slopes of a cer- 



* Sir Charles Lyell shews that the ordinary and natural course of icebergs 

 borne by currents is from the NE. to SW. ; and in his attempt to account for 

 the glacial markings in America by that agent alone, he observes that the 

 general direction is the same as that of the icebergs. But I find that, in 

 Bigsby'e map of the glacial phenomena of Northern America,* the direction in 

 by far the greater number of the markings is from NW. to SE. 

 * Quarterly Jour, of Geol. Soc, April 1851. 



