34 
THE OCEAN WORLD. 
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 hy 
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 thero 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. 
The Gulf Stream thus described by the American savant issues from 
