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CAUSE OF COLD AND MILD PERIODS, 9–36

Traces of ancient glaciers in temperate zones, 9; prevailing winds the main cause of the circulation of the ocean waters between the tropical and temperate zones, 10; general direction of prevailing winds, and how, in connection with continents, they circulate the surface waters of the sea, 11; high and low sea-levels; separation of antarctic lands from South America, 12; Captain Larsen’s discoveries in antarctic regions, 13; how low lands south of Cape Horn were submerged, 13; how the winds move more surface water southward than northward, 14; Dr. Croll’s views on winds and ocean currents, 16; under-currents of the ocean, and how caused, 16; Gulf Stream currents, 17; antarctic under-currents, 18; why the winds were able to force more of the ocean waters southward than northward at the close of the Tertiary age, 19; Mr. Alfred R. Wallace’s views on Tertiary seas, 20; how the Cape Horn channel affects the ocean currents, 21; cause of the increase of cold in southern latitudes, 22; how the Cape Horn channel is closed during ice age, and its effect on ocean currents and temperature of southern latitudes, 24; the melting of glaciers from southern lands, 27; a salt sea requisite for circulation during ice age, 28; direction of surface currents in southern seas, 29; Humboldt current, 30; Agulhas current, 32; temperature of arctic ice, 34; movement of southern icebergs, 35; glaciers south of Cape Horn, 36.