
CAPABILITIES WITH REFERENCE TO SETTLEMENT. 279 
forests already described, and on the west by the wooded district of Pem- 
bina Mountain and its northern extensions. 
- 646. The climate of the Red River Valley, like that of the whole 
interior of the continent, is an extreme one, the cold of winter being 
exceedingly severe, and the heat of the summer season also excessive. 
The courses of the summer, and winter isothermal lines across the conti- 
nent, do not require notice here, as they have already been ably discussed, 
and laid down as far as the observations now at command allow. It 
would seem, however, that between the Laurentian highlands on the east, 
and the Rocky Mountains, a great summer wave of warmth passes far to 
the north, reaching its highest latitude near the eastern base of the 
latter range; while in winter a compensating and long-continued flood of 
cold air invades the whole region vf the plains, and the eastern and 
western flanking ranges. 
647. The watershed between the Red River, and the St. Louis and 
other streams flowing into Lake Superior, forms a pretty well marked 
climatal line. The influence of the lake, and the high wooded ground 
forming a partial barrier to the north-westerly winds, renders the autumn 
in the latter region warmer; while in spring the ice accumulations of 
the lake, and wooded character of the surrounding country, keep the 
temperature much lower than in the Red River Valley. The tempe- 
rature of the Red River country, like that of the prairies generally, 
depends very closely on the direction and origin of the wind, though in 
years to come, when great regions of the plains have been planted with 
trees, much amelioration may result. A single instance—though an 
extreme one—may be mentioned. ‘On the 8th of May last year, a strong 
south wind raised the temperature at Dufferin to 100° F. At Winnepeg, 
60 miles further north, the temperature was 94°5°, the mean tempera- 
ture for the month being 52°52°. The Red River Valley, as the lowest 
trough of the interior region of the continent, would also seem to serve as 
a channel of efiux for the cold northerly winds in spring; for immediately 
on passing out of it, and up to the level of the second steppe, the vege- 
tation was found to be slightly, but distinctly, more advanced. 
648. The following notes taken at Dufferin in the Spring of 1874, 
will illustrate the advance of the season, and serve for comparison with 
other localities :— 
April ¥%5.—General surface of the prairie free from snow, and in some places already 
quite dry, though frozen below. Coulées holding large snow-banks. 
Ponds beginning to open. Ducks observed, and several of the smaller 
birds of passage. 
