Page:Physical Geography of the Sea and its Meteorology.djvu/221

Rh and becomes the centre of one of the most remarkable storm-regions in the world. My friend and fellow-labourer, Lieut. Andrau of the Dutch Navy, has made the storms upon these banks a specialty for study. He has pointed out from the abstract logs at Utrecht the existence there of some curious and interesting atmospherical phenomena to which this body of warm water gives rise. The storms that it calls up come rushing from the westward;—sweeping along parallel with the coast of Africa, they curve along it. Though so near the land, they seldom reach it. They march into these warm waters with furious speed; reaching them with a low barometer, they pause and die out. That officer has conferred a boon upon the Indiamen of all flags, for he has taught them how to avoid these dreadful winter storms of the Cape.

393. The currents and drift of the Indian Ocean.—There is sometimes, if not always, another exit of warm water from the Indian Ocean. It seems to be an overflow of the great intertropical caldron of India;—seeking to escape thence, it works its way poleward more as a drift than as a current. It is to the Mozambique-current what the northern flow of warm waters in the Atlantic (§ 141) is to the Gulf Stream. This Indian overflow is very large. The best indication of it is afforded by the sperm whale curve (Plate IX.). This overflow finds its way south midway between Africa and Australia, and appears to lose itself in passing round a sort of Sargasso Sea, thinly strewed with patches of weed. Nor need we be surprised at such a vast flow of warm water as these three currents indicate from the Indian Ocean, when we recollect that this ocean (§ 392) is land-locked on the north, and that the temperature of its waters is frequently as high as 90° Fahr. There must, therefore, be immense volumes of water flowing into the Indian Ocean to supply the waste created by these warm currents.

394. The ice-hearing currents from the Antarctic regions.—On either side of this warm current that escapes from the intertropical parts of the Indian Ocean, but especially on the Australian side, an ice-bearing current (Plate IX.) is found wending its way from the Antarctic regions with supplies of cold water to modify climates and restore the aqueous equilibrium in that part of the world. There is a general drift up into the South Atlantic of ice-bearing waters from Antarctic seas. The icebergs brought thence, being often very large and high, are set to the eastward