In spite of the counter currents and contrary squalls, we crept slowly southward to meet the southeasterly winds, the captain taking advantage of every opportunity offered by the weather. After many discouragements and setbacks, we at last crossed the equator.
One afternoon a squall rose and drove us southward. After it had blown over, it became calm again. Then we saw, far away, ripples on the ocean, which gradually came nearer and nearer. These ripples were the forerunners of the southeast trade-winds that were coming towards us. Soon after we felt a cool, gentle breeze, and a shout of joy came from all on board. Our imprisonment in the “Doldrums” was over!
The southeast trade-winds were at first very light, for we had reached just where they were dying away, close to the region of the “Doldrums,” but towards evening the breeze freshened. The next day white caps covered the sea, and life became pleasant once more. The southeast trade-winds were strong, and now we had the same beautiful blue sky as under the northeast trade-winds, and the same beautiful white and often transparent clouds.
These southeast trade-winds have also blown from time immemorial—the hot air of the South African continent bringing about the same results as the hot air of the desert of Sahara.
Then we tacked ship, and laid our course towards the west coast of Africa. I asked the captain if I should have to pass again through such dreadful regions as that of the “Doldrums” when I returned home. “No,” he replied; “on the return trip from the equatorial regions of Africa, we sail with the southeast trade-winds, south of the equator, to avoid these dreaded ‘Doldrums,’ carried onward by the southeast trade-winds until a few hundred miles off the coast of Brazil; then we get into variable, and often light winds.”
Then I thought that if our little ship were left to drift within the area of the northeast or southeast trade-winds, in the course of time she would reach the South American coast, then drift gradually northward, and, if not stranded on the way, would get into the Gulf Stream, then be carried northward, passing the latitude of New York, whence we came.
The northeast and southeast trade-winds cause the initial movement of the currents which, in their course, make the current known to us as the Gulf Stream.
The two trade-winds, blowing continually from the hot regions of Africa, drive the hot water of the tropics from Africa westward, towards South America, and this current is known as the equatorial current.
The Bight of Biafra, in the Gulf of Guinea, may be considered the head waters of this equatorial current, which runs all the way from about eighteen to twenty-five miles every twenty-four hours, until it strikes the South American coast.
This equatorial current, or stream, is a shallow river of warm water, not deeper than three hundred feet. The temperature of the water is between 75° and 80° Fahrenheit at the surface, and not more than 60° at the depth of six hundred feet,—the deeper water not being so heated by the sun, of course, as the surface water. Besides, from below there is a continual rising or flow of cold polar water.