320 Rogers's Account of two Remarkable 
to our conünent at least, of this favorite theory of the Swiss 
geologists altogether inadmissible. And, moreover, Dr. Hitch- 
cock has already exhibited the absurdity, in the special case 
before us, of supposing a glacier to be capable of conveying a 
moraine, from the ridge in Canaan, across another ridge higher 
than the one from which it started. Since it has been beauti- 
fully demonstrated, by Prof. Forbes, of Edinburgh, that every 
glacier is partially plastic, and actually flows onward, though 
very tardily, in a species of semi-fluid current, floating its 
moraines along with it, we see that it can no more ascend a 
barrier higher than its snow-fed source, than can running . 
water. 
But turning from these speculations, as too unsatisfactory, 
we now proceed to inquire whether there is not another pos- 
sible mode of transport of fragmentary rocky matter, by an 
agency in the economy of our globe much more widely active, 
and more in harmony with the facts to be explained. This 
agency, to which we are disposed to attribute the phenomena 
we have described, is the paroxysmal, or sudden and violent, 
disturbance of the slightly flexible crust of the earth, causing; 
in the period of the northern drift, a partial elevation and dis- 
placement of the bed of the great frozen sea which occupies 
the arctic latitudes, and sending its waters, with all their ice, 
in a sudden inundation, over all the northern lands of the two 
continents. Before undertaking to account, by this cause, for 
the special phenomena of the boulder. trains of Berkshire, we 
- Crave permission of the reader to explain oup views of the 
nature of continental inundation, as they are expressed in an 
address, delivered by one of us, in May, 1844, to the Associa- 
tion of American Geologists and Naturalists. 
** The paroxysmal theory, I cannot but think, will be found, 
on careful examination, to be more in agreement with the : 
mitted laws of physical dynamics than either of the more 
popular. hypotheses of the day... This. doctrine, appealing t° 
the proofs which our science furnishes of the sudden disturb- 
ances.of the level of the different tracts of the earth's surface, 
