170 THE PHENOMENA OF DRIFT, OR 



tain called the Calskills, west of the Hudson, these formations do 

 not rise as high as the primary ranges over which their bowlders 

 are scattered, by at least one thousand feet ; and I am confident 

 that every one ac(inainted with the topography of that region, will 

 admit that it is a moderate estimate to say, that these bowlders 

 must have been elevated from their original position as much as 

 one thousand feet. I doubt not that many of them have been 

 raised twice that quantity. 



It would be easy to multiply examples of this transference of 

 bowlders from lower to higher levels, where the height is less ; 

 as in a multitude of instances in the eastern part of Massachu- 

 setts, where a coarse conglomerate is strewed over the higher 

 adjoining unstratified ranges ; and in the valley of Connecticut 

 river, where syenite and sandstone bowlders are found upon the 

 narrow crest of Holyoke and Tom, having been detached from 

 the ledges several hundred feet below. But the example already 

 described is far more extensive, reaching from Vermont through 

 Massachusetts and Connecticut, into New York, and probably 

 further southwest, and is sufficient. The fact I believe will not 

 be doubted ; but it seems to me that its explanation on any known 

 hypothesis, is one of the most difficult in the whole history of 

 this subject. It is needless to spend time in showing that mere 

 currents of water, however violent, never could have done it. 

 The question remains whether icebergs, loaded with bowlders, 

 and floated by water, can have accomplished the work. But this 

 question will be more advantageously examined after detailing 

 ^ome other phenomena of drift. 



It is not easy to give a correct idea of the vast quantity of 

 bowlders scattered over some limited districts of New England. 

 The surface is sometimes almost literally covered with them ; as 

 the sketch (PL VIII, fig. 1) taken near- a place called Squam, on 

 Cape Ann, in Massachusetts, will show. The country there for 

 miles around, is almost equally full of bowlders and barren of 

 vegetation : and I might point to a multitude of other places, par- 

 ticularly in the eastern part of Massachusetts, equally crowded 

 with bowlders. 



