From the above explanations it will be seen that the impact of surface water against the antarctic ice barrier when the Cape Horn channel was closed would greatly assist the tropical waters attracted to the great low sea-level to the leeward of the obstructed strait to wash the antarctic shores while being drifted eastward by the westerly winds over the southern ocean against the Patagonian coast and the Pacific side of the closed channel, and there causing a high sea-level. This movement of the winds and currents encircling the antarctic continent is shown on map No. 1. The vast, high sea-level caused by the westerly winds drifting the surface waters against the Patagonian coast would obtain a much higher plain, were it not that so much of the water of the great drift current was required to feed the antarctic under-current which constantly sets northward from the antarctic shores; yet it would be sufficient to greatly increase the volume of the Humboldt current, which would flow in the same direction it now flows, down the South American coast to the equatorial latitudes, where it would become the main source of the great equatorial stream, and thus offset the increased southward flow of the equatorial waters through the Brazil and Mozambique streams. The equatorial stream, with its increased volume, would also move, as it moves to-day, across the Pacific; and, on gaining the western side, after sending off large streams to the northern and southern latitudes, it would pass through the East India passages into the Indian Ocean, where it would be drifted westward by the trade winds and cause a high sea-level abreast the east coast of Africa, and so become the source of the great Mozambique current, which would flow southward along the east coast of Africa, and, with the Cape Horn channel closed, would gain a much higher latitude than it would with the channel open. At this age, when the continuation of this great equatorial stream gains the latitude of the Cape of Good Hope, its waters are largely turned eastward by the great drift current of the southern ocean. Still, a considerable portion of its waters turns toward the west, forming the Agulhas current, which flows around the Cape of Good Hope into the Atlantic, where it mingles with the cooler currents which branch off from the great southern drift current; and so, in connection with the latter, it is attracted to the low sea-level caused by the south-east trade winds abreast the south-western coast of Africa, and from thence moved as a drift current by the trade winds to the equatorial Atlantic and coast of Brazil. Thus it will be seen that the Agulhas current, even with the Cape Horn channel in possession of its present wide capacity, serves to retard somewhat the advance of a cold period.