Therefore, it seems that the Cape Horn channel would continue closed or greatly obstructed while the glaciers were being melted from the lands of both hemispheres. Thus at length a mild climate would extend over the globe, and so remain until the prevailing winds slowly forced the surface waters of the sea into the southern ocean in the manner explained in previous pages, thus filling the Cape Horn channel to its present capacity, and again restoring the independent circulation of the southern ocean. While contemplating the conditions that would obtain during the melting of the ice from the antarctic lands, it will be seen that the tropical waters attracted to the great low sea-level to the leeward of the closed Cape Horn channel would eventually enter the great bight of the antarctic continent to the eastward of Graham Land, where Captain Weddell sailed to the latitude of 74° south. This deep gulf, owing to its situation, would receive the full impact of the southern movement of the tropical currents; and, as the warm waters spread over the wide sea-level, the westerly winds would convert them into a drift current, and under such conditions would be driven along the shores of the antarctic continent, past the South Indian and Pacific Oceans, and eventually, after undergoing a cooling process from the long icy passage, be forced against the Pacific side of the closed Cape Horn channel and the western Patagonian coast. While regarding the circulation of the sea during an ice age, it may be said that the ocean’s being composed of brine was the cause of its waters being able to circulate in frigid latitudes where fresh water would congeal. Consequently, this is one of the reasons why successive periods of frigidity and mildness have been brought about; for with an ocean of fresh water, repeated epochs of cold and warmth could not have occurred, because a sea composed of fresh water would have congealed while circulating in the high latitudes during a frigid age. Therefore, it required a sea of brine to maintain a liquid state during the low temperature of an ice period.