292 METEOROLOGY IN EUSSIA. 



luer, the i)revailiug direction being still west. In the steppes of South- 

 ern Eussia, and far into Central Asia, the winds are also west in June 

 and July, the prevailing direction being the opposite of that of winter. 

 Yet this has not so great an influence on all the features of the climate 

 as in Eastern Asia — 1st, because winds from other directions are more or 

 less common in both seasons ; and 2d, because there is not the contrast 

 existing in Eastern Asia between the winds from the continent and those 

 from the ocean. 



In Transcaucasia the winds are also generally easterly in winter and 

 westerly in summer, as on the northern shores of the Black Sea. Yet 

 the influence of the mountains and sea is strongly felt. On the Caspian, 

 especially, the day and night breezes are very regular in summer. The 

 Persian sailors know this very well, and in going from the south to As- 

 trachan they keep along the eastern shore, where the breezes are stronger 

 than on the western. 



We possess very few observations on the quantity of falling water, 

 and this has induced the Geographical Society to establish a more gen- 

 eral system, especially for this element. Yet we must wait at least from 

 ten to fifteen years before having reliable data from the new stations. 

 Some general features can, however, be ascertained eveu now, with the 

 aid of the few points of observation we possess. In a work on the rains 

 of Russia* I have divided the country thus : 



1. Region of prevailing summer rains, with a maximum in July: In- 

 cluding the northern part of Russia and Siberia as far as the 50° in the 

 west, and 54° in the east. 



2. Region of prevailing summer rains, with a maximum in June: In- 

 cluding the country south of the former, being the principal part of the 

 steppes (prairies) of southern and eastern Russia. 



The two regions difter, moreover, in this, that the second has a very 

 marked dry time in September and October, with easterly winds, and 

 a second maximum in aSTovember. 



Possibly the difterence of the time of most copious rains coincides 

 with the physical aspect of the country, being well wooded in the north 

 and nearly naked in the south. In the beginning of the summer the 

 grasses and corn-fields of the steppes are green, and in this condition 

 the evaporation is considerable, giving enough of vapor to the air, 

 while at the same time the cold caused by evaporation is favorable to 

 the condensation of moisture. In July the grasses are already withered, 

 the corn ripened, and in these conditions the plants evaporate much less 

 water, and therefore the rains are less frequent and copious. 



In the wooded region of the north evaporation from the leaves of 

 trees goes on the whole summer, the best conditions for rain being in 

 July, the hottest month. In the United States the conditions are simi- 

 lar. The country east of the Rocky Mountains is also principally one of 



* To be i^ublished in the "Sapiski" of the Eussian Geographical Society; also, 

 "Zeitschrift der osterreichischen Gessellschaft fur Meteorologie," year 1871, p. 193. 



