286 THE CANADIAN NATURALIST. [Yol. X. 



In Europe the northern drift descended from the Scandinavian 

 mountains towards Central Russia. It did not cover Eastern 

 Europe, nor any portion of Asia, but in the eastern hemisphere 

 it was confined to the north Atlantic. 



The greatest development of the deposits of the Ice Age is 

 adjacent to where there would have been the greatest precipita- 

 tion of moisture. We see to-day that much of Greenland is 

 covered with glaciers, but Messrs. Fielden and Kance (of the 

 Arctic Expedition of 1875-76) observed the paucity of glaciers 

 in Northern Greenland, and that neither there nor in Grinnell's 

 Land, north of about lat, 80^ 20' were icebergs (derived from 

 glaciers) met with, but all the ice was considered as floeberg ice- 

 Capt. Nares explains the dift'erence between the ordinary floe 

 and Polar sea ice. The former is only a few feet thick, and 

 meeting with obstacles, it sometimes gets piled up 40 feet or 

 more in height, while the latter is 80 or 100 feet thick, and 

 simply lifts any obstacle in its way. Now, our glacial friends, in 

 referring to the " American Ice Caps " or sheet, can only refer 

 to the region covered by northern drift before roughly outlined, 

 which did not even cover Alaska. It must also be remembered 

 that any such ice cap, as they require, would be lessening in 

 thickness as it receded from the eastern marain of the continent, 

 with its Laurentian and Appalachian Chains of mountains, to 

 cut off the Atlantic moisture, as we have just seen with regard 

 to the northern coast of Greenland. We are told that the drift 

 is found in the White Mountains at an elevation of more than 

 (3200 feet on the top of Mount Washington, with erratics (be- 

 longing to a lower topographical level) on the summit of the 

 mountain, and that all this debris was pushed up by a glacier. 

 Whilst there seems no doubt of the existence of sjlaciers in the 

 White Mountain regions, it seems really too hypothetical to place 

 a o'lacier in the White Mountains at the hisrh elevation, that in 

 moving would push up debris even 500 feet from the summit of 

 the highest adjacent mountains. 



Thickness of Ice Cap. — When Professor Agassiz annouii«ed 

 his glacier hypotheses, requiring a continental glacier to over- 

 top by 2,000 feet, the highest peaks of Mount Desert Island 

 (which are in the same latitude as Mount Washington, with 

 an elevation of more than 1500 feet) and project to Long 

 Island Sound — Professor Leslie calculated " the height of 

 the snow mass necessar}^ for producing the supposed motion of 



