GEOLOGY. 297 



subject of terraces a phenomenon that characterizes the whole breadth of 

 the continent (except perhaps at the south), and therefore one of the grand- 

 est in the science is approached in the right method, and an important 

 step is taken towards solving the great problem. It is impossible in a brief 

 notice to give a satisfactory review of the facts brought out in this long and 

 valuable paper. We mention a few of the deductions. 



1. True unstratified drift never covers the terraces; it is covered by the 

 terrace material, and is therefore of older date. 



2. The successive " beaches" and " terraces" are made out of the drift ma- 

 terial, with few exceptions, all by essentially similar operations. 



3. The river valleys were excavated before the terrace epoch, for in the 

 rocky gorges, as at Bellows Falls, drift scratches are found, near the present 

 water level; these gorges, therefore, were not closed at that time by rocky 

 barriers. 



4. The highest distinct river-terraces noticed by the author in this country- 

 are as follows : at Bellows Falls, on the Connecticut, 226 feet above the river; 

 on the Deerfield, 236 feet; on Genesee river (New York State) at Mount 

 Morris, 348 feet. Above these heights, there are other levels designated 

 beaches, and the most distinct of these are stated to be from 800 to 1200 feet 

 high ; while others, less distinct, are mentioned as found at 1200 to 2600 feet 

 in the White Mountains and elsewhere. 



5. The number of terraces is usually larger, and the height greater, on the 

 small than on large streams; there are seldom over three or four on the Con- 

 necticut; while on some of its tributaries, there are sometimes as many as 

 ten. 



6. The terraces on the opposite sides of the same stream very often do not 

 correspond in elevation. 



7. The terraces, in general, slope with the stream. They are usually 

 somewhat the highest about a gorge, as if the gorge had occasioned a higher 

 level to the river floods, and therefore more elevated depositions. They 

 show by the stratification that they are the result of water-action; though 

 stranded ice, it is urged, may have aided in making the variety of terrace 

 called moraine-terrace. 



8. The beaches also must have been produced by water, and this water 

 must have been the ocean. "Hence, I feel sure," says the author, "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." 



9. As a consequence of these conclusions, it is argued that the drift period 

 was a period of submergence for the larger part of the continent, and per- 

 haps nearly the whole, and since that period, the ocean has stood 2000 feet 

 deep over New England. 



10. The formation of the succession of beaches might have taken place by 

 a gradual elevation and drainage of the continent, without pauses in the 

 movement of elevation ; yet it is possible that some such pauses may have 

 taken place. Still, the author argues against the probability of such pauses, 

 and finally against the possibility of pauses for river terraces in general, on 

 the ground mainly of their unequal heights on opposite sides of the streams. 



11. As regards North America, "we may as yet safely say, that there is 

 no evidence of the existence of life in the seas that covered it during the period 



