CLIMATE AND CAUSES 199 



produce that high and even distribution of heat discovered as 

 ranging over so great an area." 



These conclusions have since been established as facts by the 

 recorded observations sent in from the meteorological stations at 

 Winnipeg, Fort McLeod and Fort Calgary in the south and Fort 

 Rae and Fort Simpson in the north. (See Meteorological Report 

 for 1878). 



"In 1879, my attention was mainly directed to an investigation 

 of the causes of the supposed aridity of the district lying to the 

 south. I found a parched surface, dried and withered grass, and 

 in short, every appearance of the existence of such aridity; but 

 closer examination showed that these indications were illusory. 

 At the point, "Blackfoot Crossing," latitude 50° 43', where the 

 consequence of aridity appeared the strongest, I came upon ground 

 broken up in the spring, bearing excellent crops of all kinds — oats 

 being four feet high, while, on the land outside the fence, the 

 grass was burnt up and all other vegetation withered. From this 

 I argued that the rainfall in the district was evidently ample for 

 the requirements of vegetation, but that, until the baked crust 

 was broken, it could not penetrate the ground as rapidly as it 

 fell and so a great portion was evaporated by the dry atmosphere 

 and lost. Thus, the apparent aridity vanished before the first 

 efforts of husbandry. Next to the question of aridity was that of 

 the high and even temperature of the climate. On this point, I 

 simply accumulated data bearing on the observations of former 

 years, all of which served to prove that the great plain to the 

 northwest, and north of latitude 49° extending along the Saskat- 

 chewan and other rivers between the 100th and 115th Meridians 

 and the narrow strip of coast north of Monterey, California, 

 present decided features of difference from other districts of the 

 American continent. These differences and peculiarities I shall 

 now deal with seriatum. 



TEMPERATURE. "It was long ago asserted as a principle 

 by geologists that land in quantity, situated to the southward of 

 latitude 40° north, very materially raises the temperature of land 

 lying to the north of such parallel." (Sir C. Lyell). To the 

 expression, "Land in quantity," I would add — when this character 



