114 ANNUAL RECORD OF SCIENCE ANDINDUSTRY. 



rent flowing inward, together with his explanation of the 

 physical cause of this circulation. The phenomena observed 

 have led him to suggest some striking views in reference to 

 the currents of the ocean, especially those known as streams, 

 and also the general movement of the entire body of water. 

 The Gulf Stream of the North Atlantic he considers to be 

 due by the impulse given by the trade winds to the superfi- 

 cial layer of the portion of the Atlantic over which they 

 blow, creating what is known as the equatorial current, which 

 moves constantly from the coast of Africa toward that of 

 America, the northern portion entering the Caribbean Sea 

 and the Gulf of Mexico, where it receives a further accession 

 of heat, and undergoes a change of direction, in consequence 

 of the resistance offered by the American coast-line ; thence 

 issuing in a northeasterly direction through the narrow strait 

 between Florida and the Bahama Islands. In its course ob- 

 liquely across the North Atlantic Ocean the Gulf Stream 

 gradually spreads itself out, diminishing in depth as it in- 

 creases in breadth ; and when it approaches the Banks of 

 Newfoundland, one portion of it bends round the Azores, and 

 returns in the equatorial current, thus completing the shorter 

 circuit of that horizontal movement of which the primum mo- 

 bile is the action of the trade winds. The other portion con- 

 tinues its northeasterly coast past the Banks, there meeting 

 with arctic surface currents which tend to neutralize its 

 movement and to reduce its temperature. Of these currents, 

 the principal, formed by the junction of the Labrador and 

 Greenland currents, sweeps southward along the Atlantic 

 sea-board of the United States, not only cutting this off from 

 the influence of the Gulf Stream, but reducing its winter tem- 

 perature considerably below the normal temperature of the 

 latitude. 



This current, however, is quite different from the general 

 movement of the entire Atlantic Ocean, which, he thinks, 

 takes place under precisely the same conditions as those 

 which he has pointed out in the case of the Mediterranean. 

 lie simply substitutes in the explanation the polar basin for 

 the Mediterranean, cooled down by the withdrawal of solar 

 heat, and for the Atlantic the equatorial ocean. The antago- 

 nistic conditions of temperature being constantly sustained, 

 a constant interchange between polar and equatorial waters, 



