HISTORICAL 223 



volume of the Geology of New Hampshire. This is a praiseworthy paper, 

 based on detailed study of 200 miles of the valley with spirit-level meas- 

 urements of the terrace altitudes and without good base maps. 



Upham's conception of the large element in the problem was unlike 

 that of either Dana or Hitchcock. He allowed no depression of the land, 

 but, following Adhemar, thought that the gravitational attraction of the 

 ice body on the sea deepened the ocean in the northern region. 



"It seems quite probable that the submergence of the Glacial period, of 

 which we have proof, amounting to 50 feet in southern New England, 200 feet 

 on the coast of Maine, and about 400 feet in the valley of the Saint Lawrence, 

 was not caused by any downward and upward movement of the earth's sur- 

 face, but by the attraction of the immense masses of ice." . . . 



IJpham's claim that "neither the deposition nor terracing of the modi- 

 fied drift requires any submergence, as by lakes or sea" (page 175), ap- 

 parently was meant to apply only to the New Hampshire section of the 

 valley; for, accepting statements made by E. Howe, Jr. (Popular Science 

 Monthly, volume 10, page 440), he writes: 



"These glacial sheets, when at their greatest extent and depth, caused the 

 sea to rise 200 feet higher than now at Long Island, as shown by marine 

 shells" (page 331). . 



"The valley of the Hudson River was also filled with modified drift to a 

 height at Albany of 330 feet above the sea" (page 332). 



This would seem to concede that the terraces in the IMassachusetts and 

 Connecticut section of the valley might have been built in sealevel waters. 

 And granting a stand of the sea at 330 feet at Albany should naturally 

 require a similar height of sea on the south border of New Hampshire, 

 in the same latitude and only 60 miles east. His "normal" terraces on 

 this latitude are beneath this height of 330 feet. 



The recognition of static-water influence in the lower section of the 

 valley might have suggested similar effects farther north. Upham's de- 

 scription of the valley features begins at the river head, in Connecticut 

 Lake, and proceeds down-stream. If his field-work had the same sequence 

 it helps to explain the non-recognition of the static water features in the 

 lower sections of the valley. From its source to the mouth of the Pas- 

 sumpsic Eiver, about 83 miles, the Connecticut Eiver was above the ma- 

 rine plane and the detrital deposits are to be credited wholly to the river. 

 Below that point the valley features are very different, as he recognized. 

 (See below, page 225.) 



Holding the theory of the flooded river as the only effective agent, the 

 author probably realized the inconsistency of the weak features in the 



