CLACIAL riir.NOM1.NA. 



C7 



preternatural arrest were at the same time laid on the winds, which 

 spread the temperature of the sea over the land. The alleged facta 

 observed in Norway, and stated to BUpport this view, are evidently 

 nothing but the results ordinarily observed in ranges of hills, one side 

 of which fronts cold sea-water, and the other land warmed in rammer 

 by the sun. 



The supposed effects of the varying eccentricity of the earth's orbit, 

 so ably expounded by Mr Croll, are no doubt deserving of consider- 

 ation in this connexion ; but I agree with Sir Charles Lyell in regarding 

 them as insufficient to produce any effect so great as that refrigeration 

 supposed by the theory now before us, even if aided by what Sir 

 Charles truly regards as a more important cause of cold, — namely, 

 a different distribution of land and water, in such a manner as to give 

 a great excess of land in high latitudes. 



2. It seems physically impossible that a sheet of ice, such as that 

 supposed, could move over an uneven surface, striating it in directions 

 uniform over vast areas, and often different from the present inclina- 

 tions of the surface. Glacier ice may move on very slight slopes, but 

 it must follow these ; and the only result of the immense accumulation 

 of ice supposed, would be to prevent motion altogether by the want 

 of slope or the counteraction of opposing slopes, or to induce a slight 

 and irregular motion toward the margins or outward from the more 

 prominent protuberances. 



It is to be observed, also, that, as Hopkins has shown, it is only 

 the sliding motion of glaciers that can polish or erode surfaces, and 

 that any internal changes resulting from the mere weight of a thick 

 mass of ice resting on a level surface, could have little or no influence 

 in this way. 



3. The transport of boulders to great distances, and the lodgment 

 of them on hill-tops, could not have been occasioned by glaciers. 

 These carry downward the blocks that fall on them from wasting 

 cliffs. But the universal glacier supposed could have no such cliffs 

 from which to collect; and it must have carried boulders for hundreds 

 of miles, and left them on points as high as those they were taken 

 from. On the Montreal Mountain, at a height of GOO feet above the 

 sea, are huge boulders of feldspar from the Laurentide Hills, which 

 must have been carried 50 to 100 miles from points of scarcely greater 

 elevation, and over a valley in which the stria} are in a direction nearly 

 at right angles with that of the probable driftage of the boulders. 

 Quite as striking examples occur in many parts of this country. It 

 is also to be observed that boulders, often of large size, occur scattered 

 through the marine stratified clays and sands containing sea-shells ; 



