PHYSICAL AND CLIMATAL CONDITIONS. H9 



pass westward up its sloping surface, surmount the soft 

 edge of the third steppe without much altering its form, 

 and finally terminate over 700 miles from its source, and 

 at a height exceeding the present elevation of the Lauren- 

 tian axis by over 2,000 feet. The distribution of the 

 drift equally negatives either of these theories, which 

 would suppose the passage of an immense glacier across 

 the plains. 



" In attributing the glacial phenomena of the great 

 plain to the action of floating ice, I find myself in accord 

 with Dr. Hector, who has studied a great part of the 

 basin of the Saskatchewan and also, as far as I can 

 judge from his reports, with Dr. Hay den, who, more than 

 any other geologist, has had the opportunity of becoming 

 familiar with all parts of the Western States. 



" The glaciating agent of the Laurentian plateau in the 

 Lake of the Woods region, however, cannot have been 

 other than glacier ice. The rounding, striation and 

 polishing of the rocks there are glacier work ; ancUce- 

 bergs floating, with however steady a current, cannot be 

 supposed to have passed over the higher region of the 

 watershed to the north, and then, following the direction 

 of the striae and gaining ever deeper water, to have borne 

 down on the subjacent rocks. The slope of the axis, 

 however, is too small to account for the spontaneous 

 descent of ordinary glaciers. In a distance of about 30 

 miles, in the vicinity of the Lake of the Woods, the fall 

 of the general surface of the country is only about 3 feet 

 to the mile. The height of the watershed region north- 

 east of the lake has not been actually measured ; but near 

 Lac Seul, which closely corresponds with the direction 

 required by glaciation, according to Mr. Selwyn's measure- 

 ments, it cannot be over 1,400 feet. The height of land 



