CLIMATE. 



189 



Climate. — Vegetation. 



One in the aspect of its great plains, in tbe regularity of its geological forma- 

 tions, in the vast extent of its river basins, Eussia is not less so in its climatic 

 conditions. From north to south, and from south to north, the atmospheric waves 

 are rapidly propagated, nowhere meeting with any serious obstacle. When the 

 cold northern blasts prevail, they traverse all the land, and stir up in the Black Sea 



Fig. 92.— Lines of Mean Summer and Winter Température in Russia. 



The con inuous lines pass throug'h placss having' the same mean winter temp-'ra'^ure ; the dotted lines throngh 

 places having the same mean summer temperature. 



those fierce storms which have earned for it the epithet of " inhospitable." 'V^ hen 

 the equatorial currents set in, their influence is felt to the foot of the Ural and on 

 the shores of the arctic seas. No doubt the differences of climate are considerable 

 between north and south, for, apart from the arctic islands and the Caucasian 

 lands, Eussia covers a portion of the terrestrial sphere measured by 26° of 

 latitude, and from one extremity to the other of this vast area the normal difference 

 of the climate is such that the mean summer temperature (36° Fahr.) on the Kara 

 Sea is less than the mean winter temperature (37° Fahr.) at Sebastopol, on the 



