96 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



The present difference from that level is not due, in all 

 probability, to denudation, but rather to a subsequent de- 

 pression of the level of the surface following the previous ele- 

 vation. This elevation of the surface of the land of Northern 

 Canada into a great plateau at least as high as the summit* 

 of Mount Washington, with the less elevations north and 

 south as a part of the great swell of the surface, and with the 

 simultaneous elevation of other, perhaps higher plateaus over 

 the more northern and northwestern portions of the continent, 

 and all following the majestic uplifts of the tertiary, would 

 have made a glacial period for North America, whatever the 

 position of the ecliptic, or whatever the eccentricity of the 

 earth's orbit, though more readily, of course, if other circum- 

 stances favored. Having the most elevated land of eastern 

 North America along the region pointed out, the courses of 

 the winds and the distribution of moisture would have been 

 different from the present. Canada, being then on the sea- 

 ward slope of the high land, instead of, as now, on the land- 

 ward slope, could not have had its comparatively dry climate 

 with only an annual fall of thirty inches of moisture. Ac- 

 cording to Professor Dana, in the subsidence of this plateau 

 it is probable that the same region was depressed even below 

 its present level, this probably initiating the melting of the 

 glacier, followed by a return movement, with possibly minor 

 oscillations during the same period. 4_Z>, JYbv., 1871, 373. 



BROWN ON THE INTERIOR OF GREENLAND. 



Dr. Robert Brown, in a communication on the "Interior of 

 Greenland," states that the result of all the attempted explo- 

 rations of the interior o-oes to show that this is one huge mer 

 de glace, of which the outlets and overflow are the compara- 

 tively small glaciers on the coast, though, when compared 

 with the glacier system of the Alps, they are of gigantic, size. 

 The outskirting land is, to all intents and purposes, merely a 

 circlet of islands of greater or less "extent. There are, in all 

 probability, no mountains in the interior only a high plateau, 

 from which the unbroken ice is shed on either side to the east 

 and west, the greater slope being toward the west. No moun- 

 tains have been seen in the interior, the prospect being gen- 

 erally bounded by a dim, icy horizon. Dr. Brown considers 

 Greenland susceptible of being crossed from side to side with 



