Page:Physical Geography of the Sea and its Meteorology.djvu/56

30, telling him whether the wind as he finds it has been blowing for some time, or whether it has but just shifted, and which way. Columbus first found this weedy sea on his voyage of discovery; there it has remained to this day, moving up and down, and changing its position, like the calms of Cancer, according to the seasons, the storms, and the winds. Exact observations as to its limits and their range, extending back for fifty years, assure us that its mean position has not been altered since that time. That the water which comes through the Florida Pass with the Gulf Stream flows in a circle, going to the north on the western side, and returning to the south on the east side of the Atlantic—sloughing off its drift matter always to the right, is shown not only by the Sargasso and its weeds, but it is indicated also, by our "bottle papers," by the facts developed in Plate VI., and by other sources of information. If, therefore, this be so, why give the endless current a higher level in one part of its course than another?

89. A bifurcation.—Nay, more; at the very season of the year when the Gulf Stream is rushing in greatest volume through the Straits of Florida, 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. There is the trade-wind that gives the higher level to Baffin's Bay", or that even presses upon, or assists to put this current in motion? The agency 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 tending across its course. The probability is, that this "fork" flows on towards 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's crust, and quite as cold as at a corresponding depth off the Arctic shores of Spitzbergen.

90. Winds exercise but little influence constant currents.—More water cannot run from the equator or the pole than to it. If we make the trade-winds to cause the Gulf Stream, we ought to have some other wind to produce the Polar flow; but these currents, for the most part, and for great distances, are submarine, and therefore beyond the influence of winds. Hence it should appear that winds have little to do with the general system of aqueous