208 CURRENTS OE THE SEA. 



The eastern coast of North Asia has a consi- 

 derably higher temperature than the east coast of 

 North America under the same latitudes. The 

 former is not, as is the latter, struck by a current 

 coining from the Frozen Ocean, and, besides, a part 

 of the north-east current that comes up from Japan, 

 passes through Behring's Straits, and is felt even 

 farther up on the north coast of America. 



Besides the regular sea-streams which in general 

 flow ever in the same direction, there are also some 

 which are periodically reversed; that is, some 

 wliich run, during one part of the year in one 

 direction, during the rest in another. Thus, 

 between New Guinea and the island group of 

 the Carolinas we find a current wliich runs 

 eastwards from April to October, and from October 

 to April westwards, answering exactly to the winds 

 which prevail during the same periods. We meet 

 with like periodical currents in the China Seas, 

 in the Indian Ocean, &c, &c. Their dependence 

 upon the direction of the wind is everywhere 

 obvious. The same is true of many irregular 

 currents which are set up and cease again as the 

 winds rise and fall. 



The knowledge of the periodical currents is, 

 like that of the regular streams, of great 

 consequence to sailors. But the former have 

 not the importance for the study of climate 



