30 
THE PHYSICAL GEOGRAPHY OF THE SEA. 
14. Nay, more ; at the very season of the year when the Gulf 
Stream is rushmg in greatest volume through the Straits of Flor- 
ida, and hastening to the north with the greatest rapidity, there is 
a cold stream from Baffin's Bay, Labrador, and the coasts of the 
north, running to the south with equal velocity. Where is the 
trade-wind that gives the high level to Baffin's Bay, or that even 
presses upon, or assists to put this current in motion ? The agen- 
cy of winds in producing currents in the deep sea must be very 
partial. These two currents meet off the Grand Banks, where 
the latter is divided. One part of it underruns the Gulf Stream, 
as is shown by the icebergs which are carried in a direction tend- 
ing across its course. The probability is, that this " fork" con- 
tinues on toward the south, and runs into the Caribbean, Sea, for 
the temperature of the water at a little depth there has been found 
far below the mean temperature of the earth, and quite as cold as 
at a corresponding depth off the Arctic shores of Spitzbergen. 
15. More water can not run from the equator or the pole than 
to it. If we make the trade-winds cause the former, some other 
wind must produce the latter; but these, for the most part, and 
for great distances, are submarine, and therefore beyond the influ- 
ence of winds. Hence it should appear that luinds have little to 
do with the general system of aqueous circulation in the ocean. 
The other "fork" runs between us and the Gulf Stream to the 
south, as already described. As far as it has been traced, it war- 
rants the belief that it, too, runs up to seek the so-called higher 
level of the Mexican Gulf. 
16- The power necessary to overcome the resistance opposed 
to such a body erf water as that of the Gulf Stream, running sev- 
eral thousand miles without any renewal of impulse from the forces 
of gravitation or any other known cause, is truly surprising. It 
so happens that we have an argument for determining, with con- 
siderable accuracy, the resistance which the waters of this stream 
meet with in their motion toward the east. Owing to the diurnal 
rotation, they are carried around with the earth on its axis toward 
the east with an hourly velocity of one hundred and fifty-seven* 
miles greater when they enter the Atlantic than when they arrive 
off the Banks of Newfoundland. In consequence of the difference 
* In this calculation the earth is treated as a perfect sphere, with a diameter of 
7925-56 miles. 
V 
