THE WATERS OCEANIC. 53 



rials along the bottom. So too, though we find more irregularity in the beaches, 

 yet along what was by the supposition once the line of a coast, they are level, 

 while seaward they are rounded and sloping, like beeches now forming. 



In the case of moraine terraces, however, I think it unquestionable that some 

 other agent, besides water, must be called in to explain their formation. If masses 

 of ice were stranded for a long time on the spot where they occur, and currents of 

 water had accumulated the sand and gravel around them, and afterwards the 

 waters had retired and the ice melted, it seems to me that the surface would be 

 left in that peculiar condition which the phenomena under consideration present. 

 I can, however, conceive how strong eddying currents alone might pile up sand and 

 gravel to some extent in a similar manner. But when I meet with these ridges, 

 knolls, and depressions, over wide surfaces, and a hundred feet in height and 

 depth, I have strong doubts whether we must not call in the aid of stranded ice. 

 Water, however, even in this case, must have been the principal agent. But more 

 on this subject in a subsequent paragraph. 



12. If the preceding conclusions be admitted, it will follow, that at as high a 

 level as we can find accumulations of rounded and sorted materials, we may be 

 sure of the long continued presence of water, since the drift period, or during the 

 alluvial period. Hence I feel sure from the facts which I have stated, that over the 

 northern parts of this country, this body of water must have stood at least 2000 feet 

 above the present sea level; and I might safely put it at 2500 feet: for up to that 

 height I have found drift modified by water. At an equal height have I observed 

 it on the continent of Europe. 



13. The water that stood at such a height on the continents, must have been 

 the ocean. For most of the mountains in the United States are below that level, 

 and consequently must have been enveloped by the waters. Not a few instances 

 occur, indeed, nearly all the examples of beaches which I have described are of this 

 character, in which Plate XII, Fig. 4 represents their situation. Between the old 

 beach and the present ocean there are no barriers high enough to prevent the water 

 that covered the beach from communicating with the ocean: and the fact that the 

 surface, almost everywhere, is smoothed, rounded, and striated by the drift agency, 

 even to the bottom of the valleys, precludes the idea that rocky barriers existed 

 when the beaches were formed high enough to shut out the ocean : for those 

 beaches were formed since the drift period. 



I know of ho way of avoiding the conclusion that these waters were oceanic, 

 unless it be by supposing barriers to have been formed by vast accumulations of 

 detritus and ice, which subsequently disappeared, after having formed and sus- 

 tained lakes and inland seas long enough to form the beaches. But this must 

 have required barriers, sometimes perhaps a hundred miles long, and in some 

 places at least 1000 feet high. If they once existed, and were formed of detritus, 

 what can have become of it? Was it carried into the ocean? This would have 

 been impossible by the breaking away of the barrier, even though ruptured in 

 several places; and we may not, by the very supposition, call in the breakers 

 of an ocean to wear it away. YVas it an icy barrier? Is it not incredible that 

 an embankment of this material, so many miles long, and so many hundred 



