30 THE OCEAN WOELD. 



general, the current of air there is an ascending current. This belt, 

 which does not exactly correspond with the Equator, is called the Zone 

 of Calms, where atmospheric tempests frequently occur, and the winds 

 make the entire tour of the compass, which has acquired for them the 

 name of tornadoes. 



The trade-winds, whose movement towards the west is retarded by 

 the friction which the waves of the ocean oppose to them, communi- 

 cate to these waves, by a sort of reaction, a tendency towards the west, 

 or, to speak more exactly, towards the south-west in the northern hemi- 

 sphere, and towards the north-west in the opposite hemisphere. The 

 currents on the surface of the water which result from this reaction, 

 reunite under the Equator, and form the grand equinoctial current 

 which impels the waters of the east towards the west. This movement 

 is stronger at the edges than in the middle of the current, because the 

 force which produces it acts there with more energy : it results from 

 this, that the currents bifurcate more readily when any obstacle pre- 

 sents itself to its movement. In the Atlantic Ocean, bifurcation takes 

 place a little to the south of the Equator ; the southern branch descends 

 along the coast of Brazil, and probably returns by reascending along the 

 west coast of Africa. The northern branch follows the coast of Brazil 

 and Guiana, enters the Sea of the Antilles, and directs its course, rein- 

 forced by the current which reaches it from the north-east, into the 

 Bay of Honduras, traverses the Yucatan Channel, and enters the Gulf 

 of Mexico, whence it debouches by the Florida Channel, under the 

 name of the Gulf Stream. Of this oceanic marvel Dr. Maury observes 

 that " there is a river in the bosom of the ocean ; in the several 

 droughts it never fails, and in the mightiest floods it never overflows ; 

 its banks and its bottom are of cold water, while its current is of warm ; 

 it takes its rise in the Gulf of Mexico, and empties itself into the Arctic 

 Seas. This mighty river is the Gulf Stream. In no other part of the 

 world is there such a majestic flow of water ; its current is more rapid 

 than the Amazon, more impetuous than the Mississippi, and its volume 

 is more than a thousand times greater. Its waters, as far as the 

 Carolina coast, are of indigo blue ; they are so distinctly indicated 

 that their line of junction can be marked by the eye." Such is Dr. 

 Maury 's description of this powerful current of warm water, which 

 traverses the Atlantic Ocean, and influences in no slight manner the 

 climate of Northern Europe, and especially our own shores. 



