GEOLOGICAL SEASONS. 193 



the equatorial regions. If, furthermore, the cold of the 

 arctic regions equals that of the antarctic, the northern 

 trades will meet the southern trades at the equator, and 

 the equatorial current will flow westward midway between 

 the tropics. If, as at present, the cold of the southern 

 hemisphere is in excess, the southeast trades will possess 

 greatest force, and pass to the north of the equator, de- 

 termining the position of the equatorial current somewhat 

 nearer to the northern tropic than to the southern. If, on 

 the contrary, the cold of the northern hemisphere should, 

 as we have supposed, under the influence of high eccen- 

 tricity, become considerably in excess of the cold of the 

 southern hemisphere, the equatorial current would be 

 shifted to some latitude south of the equator. 



The configuration of the continents is such that the po- 

 sition of the equatorial current exerts a most important 

 influence upon the direction of its trend out of the torrid 

 zone. At the present time, for instance, with this current 

 a few degrees north of the equator, the larger portion of 

 it is deflected northward by the shore of South America; 

 and passing through the Caribbean Sea and the Gulf of 

 Mexico, issues as the Gulf Stream, which diagonally crosses 

 the North Atlantic, and impinges upon the shores of West- 

 ern Europe. Its movement across the Atlantic is aided, 

 and we may well believe is caused, by the prevailing 

 westerly winds of the North Temperate Zone. With the 

 equatorial current flowing as far south of the equator as 

 would be implied in the extension of the persistent snow- 

 cap of the northern hemisphere, the contact of the current 

 with the coast of South America would take place to the 

 south of Cape St. Roque, and its deflection would be into 

 the South Atlantic. Whatever influence the Gulf Stream 

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