Page:A sketch of the physical structure of Australia.djvu/97

85 (May to September) the trade winds are confined to the Tropics, and blow all along the north-eastern and the northern coast of Australia. At that season calms, and light, and variable airs prevail all along the north-west coast for a distance of at least 200 or 300 miles from the shore. The trade wind which blows "home" on the eastern coast is lifted by the ascending current that rises from the heated plains of the interior, and does not descend to the sea again on the north-west till after it has passed beyond them for that distance. In the summer (November to March) the sun draws the trade wind as far south as 30° or 35°, so that easterly winds prevail all along New South Wales, and frequently blow through Bass's Straits and along the southern coast of Australia. At that time the sun being perpendicular over Northern Australia heats it to such an extent that instead of mere calms on the north-west coast the wind rushes from the north-west to the land, the current is reversed instead of suspended, and occasional winds and gales from the west and north-west prevail all along the northern coast. That season is thence called that of the north-west monsoon. These winds bring heavy thunder