THE NEW SCIENCE OF METEOROLOGY 



theory that ocean currents are due to the trade- winds 

 has again come into favor. Indeed, very recently a 

 model has been constructed, with the aid of which it is 

 said to have been demonstrated that prevailing winds 

 in the direction of the actual trade- winds would pro- 

 duce such a current as the Gulf Stream. 



Meantime, however, it is by no means sure that 

 gravitation does not enter into the case to the extent 

 of producing an insensible general oceanic circulation, 

 independent of the Gulf Stream and similar marked 

 currents, and similar in its larger outlines to the polar- 

 equatorial circulation of the air. The idea of such 

 oceanic circulation was first suggested in detail by 

 Professor Lenz, of St. Petersburg, in 1845, but it 

 was not generally recognized until Dr. Carpenter in- 

 dependently hit upon the idea more than twenty 

 years later. The plausibility of the conception is ob- 

 vious; yet the alleged fact of such circulation has 

 been hotly disputed, and the question is still sub 

 judice. 



But whether or not such general circulation of ocean 

 water takes place, it is beyond dispute that the recog- 

 nized currents carry an enormous quantity of heat 

 from the tropics towards the poles. Dr. Croll, who has 

 perhaps given more attention to the physics of the 

 subject than almost any other person, computes that 

 the Gulf Stream conveys to the North Atlantic one- 

 fourth as much heat as that body receives directly from 

 the sun, and he argues that were it not for the trans- 

 portation of heat by this and similar Pacific currents, 

 only a narrow tropical region of the globe would be 

 warm enough for habitation by the existing faunas. 



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