Glaciation of Mountains^ Etc. — Upham. K37 
Hudson bay, as is indicated by the general divergence of 
striic and dispersal of drift from that region; but a nearly 
equal depth of ice seems to have extended thence westward to 
lake Superior and over the area of James bay and the south- 
ern part of Hudson bay to the vicinity of lake Winnipeg and 
Reindeer lake. 
Similarly, northwestern Europe was covered by an ice-sheet 
which moved radially outward in all directions from the 
mountains of Scandinavia, extending southeast and nouth over 
about half of Russia and Germany, and southwest across the 
area of the North sea to Britain, where the mountains of 
Scotland, Wales, and Ireland, were smaller independent centers 
of glacial outflow. Farther to the south, a large area in the 
Pyrenees, and a still larger district in the Alps and adjoining 
country were covered by ice. In North America, likewise, the 
Rocky mountains and the Sierra Nevada bore glaciers of great 
extent along a distance of several hundred miles south of the 
continental ice-sheet ; but no such local glaciation is known 
along the Appalachian mountain belt south of the general 
boundary of the drift. 
Alpine glaciers are wholly inadequate to give a mental 
picture of the North American and European ice-sheets, 
though they suggested to Louis Agassiz fifty years ago the 
grand generalization that the drift of these northern countries 
was formed by land-ice covering continental areas, as the 
ancient glacier of the Rhone poured westward from the Fins- 
teraarhorn, the Jungfrau, Monte Rosa, and Mont Blanc, 
across the great valley of Switzerland where now are the 
lakes of Geneva and ^euchatel, to the Jura range on which 
its immense bowlders are stranded. Even that former exten- 
sion of ice from the Alps was small in comparison with the 
ice sheet of northwestern Europe, which stretched 2,000 miles 
from west to east, with a maximum width of 1,")(X) miles; 
and the North American ice-sheet had far greater extent, 
reaching 4,0(X) miles from Newfoundland and Labrador to the 
Pacifjc ocean and Alaska, and from the Ohio, Missouri and 
Columbia rivers to the Arctic ocean. The only similar tracts 
of ice now existing upon the globe are the Antarctic ice-sheet 
and that which occupies the interior of Greenland. 
Around the south pole an ice-sheet extends outward on all 
sides, to an average distance of 1,000 miles or more from the 
