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I. — On the Causes of the Great Currents of the Ocean. 

 By Mr. Alderman Hopkins. 



[Read Nwemher ith, 18S1 .] 



In addition to the disturbances produced in the water of the 

 ocean by tidal action, there are extensive movements of it 

 that are known by the name of Oceanic Currents. Different 

 opinions have been entertained respecting the causes of these 

 currents, but they have generally been ascribed to the rotation 

 of the globe on its axis causing the surface of the earth to 

 move eastward, faster than the water which is contained in 

 the bed of the ocean. The influence of wind on the surface 

 of the water has been occasionally recognised, but mostly as 

 a modifying cause, affecting only the surface and the water 

 immediately under it. 



For instance, in Lizars' Atlas, which is a popular compilation 

 from what are considered the best authorities, it is said, — 

 " Besides the tides there is a regular motion of the whole 

 waters of the ocean, which carries them from east to west in 

 the tropical regions, and as far as 30 degrees of north and 

 south latitudes in the same direction as the trade winds. 



