8 On the Physical Geology of the United States, Sc. 
rents both of the ocean and the atmosphere have a tendency to 
a circular flow; those flowing from the equatorial toward the 
polar regions bend more and more to the eastward as they ad- 
vance into higher latitudes, while those flowing from the poles 
towards the equator, bend to the westward as they approach the 
tropical regions. This may be seen in the southwest winds of 
the United States and the Gulf Stream, in one case—and in the 
prevailing currents of the atmosphere and of the Atlantic Ocean, 
that cause the trade winds and the equatorial current, in the 
other.* 
The bending of these currents of the ocean and of the atmo- 
sphere to the eastward in the northwardly flow, and to the 
* In regard to the great currents of the ocean, the following are said to have been 
distinctly recognized as permanent, and with slight variations in velocity. Nu- 
merous local and variable currents have been noticed, which are caused by sub- 
divisions and deflections of the more general ones, and by those causes that pro- 
duce eddies. Theory would render others probable that have not been recognized. 
A. (1.) The equatorial current of the Atlantic is divided by the eastern coast 
of South America into two branches. The larger flows to the W. and N. W. 
into the Caribbean Sea and Gulf of Mexico, causing a higher level than that of 
equilibrium, and a flow through the Gulf of Florida called the Gulf Stream; the 
other flows along the coast of Brazil toward Sandwich Land. 
(2.) The equatorial current of the Pacific has a very moderate westward flow, 
which is nearly uniform and constant, like the trade winds in the central and 
western parts of that ocean. 
Branches of this current are said to set northward along the coasts of China 
and Japan, corresponding to the Gulf Stream; and southward by New Holland 
toward the Antarctic regions. 
(3.) The equatorial current of the Indian Ocean has a northwest flow, caused 
by a deflection of the same current from the Pacific among the reefs and islands 
between which a part of it passes, and by the southwardly polar current. The 
northwest current flows west from Cape Comorin to the African coast, thence 
along that coast through the Mozambique Channel to the Lagullas Banks near the 
Cape of Good Hope, where it meets the Lagullas current from the Antarctic seas. 
Numerous ccunter and variable currents are also found in the Indian Ocean. 
B. (1.) The polar current from the north issues from Davis’s Strait and floats 
icebergs even against the wind, and against the Gulf Stream in the vicinity of the 
Banks of Newfoundland. This current proceeds southwardly, and owing to the 
rotation of the earth, it presses to the westward along the coast of the United 
States, and gives that coldness to the water that modifies so materially the climate. 
(2.) Another polar current sets from the north in the Atlantic Ocean near its 
eastern shore, and these two polar currents by their action on the Gulf Stream, 
deflect a part of its waters across the Atlantic and along the western coasts of Eu- 
rope, to join again the equatorial current. 
(3.) Part of the Lagullas current flows along the southwest coast of Africa to- 
wards St. Helena and Ascension, to join the equatorial current. 
(4.) Another in the Pacific sets along the west coast of South America to join 
the westward flow from the Gallipagos. 
