CLIMATE 267 



tic Circle, in longitude 146, and thence flows southwest- 

 ward to its mouth. It is navigable for small steamers 

 throughout its course in Alaska, and when not closed by 

 ice, that is, from June to October, carries much traffic, 

 since the greater part of the food, supplies, machinery and 

 other goods for the support of the mines in Alaska and 

 the Klondike come by this route. 



North of the Yukon most of the land is permanently 

 frozen at a depth, thawing only near the surface in sum- 

 mer. Wherever the slopes are at all gentle such ground 

 is marshy, forming the well-known tundra of the Arctic 

 regions. 



CLIMATE. 



We must speak of the climates rather than the climate 

 of Alaska, for different parts of the Territory differ in 

 climate, not in degree only, but in kind. The Pacific coast 

 has a climate of its own, the coast of Bering Sea has an- 

 other, and both differ widely from that of the interior. 



The climate of the Pacific coast, from Portland Canal in 

 the extreme southeast to Attu Island at the west end of 

 the Aleutian chain, may be characterized, in a word, as 

 ' chilly.' Take the well-known climate of San Francisco 

 with its dampness, fogs, and cold sea winds, reduce the 

 temperature 15 to 18 degrees and increase the dampness 

 and fog in proportion, and you have a fair idea of the 

 climate of the Alaska Pacific coast. At Sitka, in latitude 

 57, the mean annual temperature is 43 Fahr., which is 

 about the same as at Eastport, Maine, 12 degrees farther 

 south. The extreme range of temperature on record at 

 Sitka is from a trifle below zero Fahrenheit to 90 above, 

 and the monthly mean temperatures range from 31 to 56 

 only, illustrating the wonderfully uniform temperature of 

 the Pacific coast. At Kadiak, 16 degrees farther west 

 and a degree farther north, the mean temperature is 2 



