In the case of such a sudden transfer, the eastern coast of America being carried round in an opposite direction, might strike against a large body of water with tremendous violence, and a considerable part of the continent might be submerged. This disturbance does not occur, because the water of the stream, as it advances gradually into new zones of the sea, acquires by friction an accelerated velocity. Yet as this motion is not imparted instantaneously, the fluid is unable to keep up with the full speed of the new surface over which it is successively brought; and Herschel, in his Treatise on Astronomy, observes, when speaking of the trade winds, it lags or hangs back in a direction opposite to the earth’s rotation, that is from east to west; {24a} and thus a current which would have run simply towards the north but for the rotation, may acquire a relative direction towards the west, or become a south-easterly current. {24b} The most extensive and best determined system of currents is that which has its source in the Indian Ocean, under the influence of the trade winds; and which, after doubling the Cape of Good Hope, inclines to the northward, along the western coast of Africa; then crosses the Atlantic near the Equator, and is lost in the Caribbean Sea; yet seems to be again revived in the current which issues from the Gulph of Mexico, by the Straits of Bahama, and flows rapidly in a north-easterly direction, by the bank of Newfoundland, towards the Azores. Rennell informs us, that the Lagullas current, so called from the cape and bank of that name, is formed by the junction of two streams flowing from the Indian Ocean, the one from the channel of Mozambique, down the south-east coast of Africa, the other from the ocean at large.—The collective stream is from ninety to one hundred miles in breadth, and runs at the rate of from two and a half to more than four miles per hour. It is at length turned westward by the Lagullas bank, which rises from a sea of great depth, to within one hundred fathoms of the surface. It must therefore be inferred, says Rennell, that the current here is more than one hundred fathoms deep, otherwise the main body of it would pass across the bank, instead of being deflected eastward, so as to flow round the Cape of Good Hope. From this Cape it flows northward, along the western coast of Africa, taking the name of the South Atlantic current. It then enters the Bight or Bay of Benin, and is turned westward, partly by the form of the coast there, and partly, perhaps, by the Guinea current, which runs from the north into the same great bay. From the centre of this bay proceeds the Equatorial current, holding a westerly direction towards the Atlantic, which it traverses from the coast of Guinea to that of Brazil, flowing afterwards by the shores of Guiana to the West Indies. The breadth of this current varies from one hundred and sixty to four hundred and fifty geographical miles, and its velocity is