INLAND AND ISLAND; EFFECTS. 185 



agricultural population, on these islands the only 

 corn produced is a poor barley, which however can 

 ripen with a mean summer temperature no higher 

 than 8° C. (46°*4 F.) It is true that their winters are 

 not very severe, but the summer fails to supply the 

 warmth requisite for the usual cultivated crops. 

 At the North Cape even barley can no longer be 

 cultivated, and the birch, which a little farther 

 south, under 76° north latitude, is still met with, here 

 disappears. On the same isotherm in the country 

 about the Cumberland-house Factory, and in 

 the neighbourhood of Lake Winnipeg, in the in- 

 terior of North America, the ground is, as we are 

 assured by travellers, covered with forests, and is 

 fruitful, and well fitted for the growth of corn. 

 Even at Yakutsk, with a mean temperature for the 

 year of -9°*7 C. (14°*54 F.), and for the winter 

 months -42°-5 C. (-44°-5 F.), forest trees, and all 

 plants which, like wheat and rye, only need a short 

 but hot summer, grow well, because the mean 

 summer temperature, notwithstanding the ever- 

 frozen sub-soil at three feet depth, is as high as 

 16° C. (60°-8F.), and is thus equal to that of 

 Stockholm and of Konigsberg. In Nova 

 Zembla the year gives the mean temperature as at 

 Yakutsk. Nevertheless this island is quite unin- 

 habitable, and devoid of vegetation, because the 

 mean summer temperature does not rise above 

 2°-5 C. (36°-5 F.) The warmest day in the year 



A 



