METEOEOLOGY IN RUSSIA. 



289 



rior are there nearest to the ocean. Air is also drawn into Central 

 Asia from the Arctic and Atlantic Oceans, but, having a much longer 

 distance to travel before reaching the mountains, and being originally 

 colder, it does not cause such a great i)recipitation. The in-draught 

 from the north and west is also less regular, since the pressure over the 

 Arctic is not high in summer, and the air of the Atlantic is also drawn 

 toward the deserts of Africa where the pressure is low in summer. 



The Asiatic monsoons were first known to the Europeans in India, and 

 therefore we often find them called Indian monsoons. It is also supjiosed 

 that they always blow from the northeast in winter, (dry monsoons,) and 

 from the southwest in summer, (wet monsoons.) In the lately published 

 " pilot-chart " of the British admiralty the monsoon region is repre- 

 sented as extending northward to Southern China only. But the 

 winds much farther to the north have the same periodical character. 

 Even in Northern China, Japan, Mantschuria, the Russian Amoor 

 provinces, and on the western coast of the Sea of Ochotsk, cold, dry 

 winds (northwest) from the interior of the continent generally jirevail in 

 winter, while in summer they are from the sea, bringing cloud and rain. 

 There is, therefore, no reason why we should not extend the Asiatic 

 monsoons to these countries, since their climates are of the same char- 

 acter as that of India, the temperature alone excepted, the winter being 

 the clear, dry time of the year, and the summer being the rainy period. 

 Sometimes the summer monsoon extends as far inland as Lake Baikal. 

 In 18G9 this lake, the greatest fresh-water basin of the world except 

 Lake Superior, rose more than 10 feet above its ordinary level, causing 

 disastrous floods in the neighborhood. Such copious and long-continued 

 rains in summer are unknown in European Russia; the great rivers are 

 unaccompanied with freshets in summer, especially those traversing 

 great lakes, as the Neva. 



The following table shows the periodical character of the winds in 

 the regions of Eastern Asia : 



Percentage of tvinds at Nicolajevsic, mouth of the Amoor. 



Months. 



N. NE. E. SE. S. SW. W. NW 



January 



February. .. 



March 



April 



May 



June 



July 



August 



September . 



October 



November .. 

 December ... 



19^ 



26. 



36 



23 



13 



9 



6 



9 



23 



36 



29 



40 



22 



