112 CURRENTS IN THE OCEAN. [SECT. xin. 



where the rotatory motion of the surface of the earth is 

 very much less than it is between the tropics, on account of 

 th,eir inertia, they do not immediately acquire the velocity 

 with which the solid part of the earth's surface is revolving 

 at the equatorial regions ; from whence it follows that, 

 within twenty-five or thirty degrees on each side of the 

 line, the ocean appears to have a general motion from east 

 to west, which is much increased by the action of the trade 

 winds. This mighty mass of rushing waters at about the 

 tenth degree of south latitude is turned towards the north- 

 west by the coast of America, runs through the Gulf of 

 Mexico, and, passing the Sfcraits of Florida at the rate of 

 five miles an hour, forms the well-known current of the 

 Gulf-stream, which sweeps along the whole coast of America 

 and runs northward as far as the bank of Newfoundland, 

 then bending to the east it flows past the Azores and 

 Canary Islands, till it joins the great westerly current of 

 the tropics about latitude 21 north. According to M. de 

 Humboldt, this great circuit of 3800 leagues, which the 

 waters of the Atlantic are perpetually describing between 

 the parallels of eleven and forty-three degrees of latitude, 

 may be accomplished by any one particle in two years and 

 ten months. In the centre of this current is situated the 

 wide field of floating sea-weed called the grassy sea. Be- 

 sides this there are branches of the Gulf-stream, which 

 convey the fruits, seeds, and a portion of the warmth of the 

 tropical climates to our northern shores. 



The general westward motion of the South Sea, together 

 with the south polar current, produce various water-courses 

 in the Pacific and Indian Oceans, according as the one or 

 the other prevails. The western set of the Pacific causes 

 currents to pass on each side of Australia, while the polar 

 stream rushes along the Bay of Bengal : the westerly current 

 again becomes most powerful towards Ceylon and the Mal- 

 dives, whence it stretches by the extremity of the Indian 



