The calms in the so-called "belt of calms" were fortunately not of long duration, for in 6° 43' N., and 28° 49' W., a fresh south-east wind sprang up. When we came within the influence of the south-east trade-wind, we endeavoured to approach the coast of South America, for the purpose of observing the currents in that latitude, this being one of the investigations suggested by the letter of instructions drawn up by Alexander v. Humboldt. The great oceanic stream, which, on leaving the western coast of Africa takes a westerly direction, is divided by the projecting American Continent into two branches, of which the stronger turns N.W. towards the Caribean Sea, while the weaker moves south-west along the coast of Brazil.
We had already felt its influence whilst in the zone of calms, and it became still more perceptible the more the equator was approached. The continuance of the south-easterly trade forced us to cross the Line at a more westerly point than usual. This, however, causes no disadvantage to a good sailing ship; nay, Commander Maury has proved indisputably that ships make extremely short passages, which reach the Equator so far to the west that they run a risk of hugging the coast too closely. Those on the other hand, which, from over-anxiety to avoid the current, keep too far to the east, lose much time, being compelled to pass weeks in the zone of calms, which increases in breadth towards the east, whereas the others come very little in contact with it, and avail themselves of the changes of wind near the shore, to double the Cape of St. Roque on the American coast, so much dreaded by the former. We cannot here forbear expressing our high admiration of the great merits of Mr. Maury, whose classical work on the physical geography of the sea, as well as his inestimable wind and current charts, deserve the especial attention of all who navigate these seas.
The nearer we approached the Line, the more striking became the aspect of the southern constellations. The light of the northern polar star grew fainter and fainter, its altitude diminished, and it at length entirely disappeared. But, on the other hand, the Southern Cross, the Magellan clouds, the ship Argo on the "coal-bags," or starless, dark spots of the southern hemisphere, became more elevated in proportion as the northern sky moved away, and for a moment we felt some difficulty in recognizing our old acquaintances of the northern hemisphere in their relation to the new stars.