But, in order that the tropical currents should be able to flow into the high latitudes, in quantities sufficient to cause all lands and seas situated in such latitudes to enjoy a mild climate, it would be necessary that the land should extend unbroken, or nearly so, from the arctic to the antarctic circles. Thus, with a continent of such vast extent, the westerly winds would blow the surface waters of the ocean away from the eastern shores in the high latitudes, and so cause extensive low sea-levels; while the easterly winds of the torrid zone would heap the surface waters of the ocean against the eastern tropical shores of the continent. Consequently, the warm waters of the tropical high sea-level would be moved by gravity to the low sea-levels of the high latitudes, even to the arctic and antarctic regions, and thus afford them a mild climate. In this way we account for the mild climate enjoyed on lands and seas within the high latitudes during the warm epochs anterior to the glacial periods. As the western continent is the only land that extends unbroken from the equator to the cold latitudes of both hemispheres, thus affording an opportunity for the prevailing winds to move the tropical waters into the high latitudes, I will call attention to that portion of the continent which extends far southward into the southern ocean, where the winds and ocean currents have the greatest range and power to affect the climate on different parts of the globe. Here we see South America separated from the antarctic continent by a wide channel of deep water, where the westerly winds blow with great force. The space now covered by this interesting channel, owing to its being situated in the high southern latitudes, must have been occupied by a channel of comparatively small capacity, or else an isthmus of low land uniting the southern portion of South America with the antarctic continent during the warm epochs when the beds of the ancient seas of the northern hemisphere contained a considerable portion of the water now swelling the southern ocean. Therefore, the obstructions which separated the Pacific Ocean from the South Atlantic furnished opportunity for the westerly winds to force the surface waters of the sea away from the leeward side of such obstructions, causing a vast low sea-level, sufficient to attract the tropical waters heaped against Brazil by the trade winds into the southern seas in adequate quantity to cause a mild climate throughout the antarctic regions through long periods of time. Recent discoveries have proved that these high southern latitudes have been subject to great changes of climate. According to the reports from the Dundee whalers, while searching for seal in the icy seas that surround the South Shetlands, they met with the Norwegian ship “Jason,” Captain Larsen, who had traced the eastern shore of Graham Land to 68° south latitude, noting two active volcanoes.