30 miles a day. This current rounds Cape Comorin and the southern coast of Ceylon, where it sometimes attains the rate of 45 miles a day, and passes into the Bay of Bengal, reinforcing the general north-east movement of its own water, circulating round the head of this gulf, and then undergoing a deflexion by the coast line towards the entrance of the Strait of Malacca, into which it flows at the rate of from 20 to 24 miles per day. "When the sun crosses the equator towards the south at the autumnal equinox, so that its heating power is exerted on South Africa, the indraught of air towards that continent reproduces the north-east monsoon; and this restores the westerly drift, which extends over the Indian Ocean as far as 5 S. lat., giving place at about that parallel to the equatorial counter-current.
The surface of the southern Indian Ocean, between the parallel of 10 S. and the Tropic of Capricorn (the precise limits varying with the season), is pretty constantly traversed by the south-east trade-wind, which gives a steady westward movement to its water, known as the south equatorial current, whose average rate is about 14 miles per day. This meets the eastern coast of Madagascar, and that of continental Africa to the north and south of it; and, its onward flow being thus checked and deflected southwards by the trend of the land, it forms a strong current which sets along the Natal coast towards Cape Colony. The strength of this current varies according as the north-east or the south-west monsoon is blowing; for the movement produced by the former reinforces it, while that pro duced by the latter weakens it, by deflecting northwards a portion of the water which the southern equatorial current brings to the coast of Africa, and drifting it towards the Indian peninsula. When flowing with its greatest force and velocity, the Natal current[1] is scarcely, if at all, inferior to the Gulf Stream where it issues from the Florida Strait. When passing Cape Corrientes, at the southern extremity of the Mozambique Channel, it is said to have a rate of 80 miles per day, and has been even said to rush, under a rare combination of impelling forces, with a velocity of 140 miles per day. Its rate gradually diminishes, however, until, off Cape Colony (where it is known as the Agulhas current), it has a velocity of about 50 miles per day. The warmth it carries has a very import ant influence in ameliorating the climate of Cape Colony; for this would otherwise suffer from the importation of the low temperature brought by the Antarctic current which there meets it.[2] When the Agulhas current is at its strongest, it carries a temperature of 79 as far west as the meridian of 15 E. But when the drift of the monsoon wind countervails that of the south-east trade, instead of reinforcing it, the temperature of the Agulhas current is lower and its force less. Whilst a portion of this current rounds the Cape and becomes a tributary of the South African current of the Atlantic (thus carrying away the excess brought into the basin of the Indian Ocean by the Malacca current), the principal part of it is deflected to the south and east, partly by the agency of the Antarctic current, but chiefly under the influence of the westerly winds or "anti trades," that prevail throughout the southern water-zone which almost continuously girdles the globe between the parallels of 40 U and 60 S. Thus there is here a pretty constant retrograde set of surface-water (corresponding with the southern connecting current of the South Atlantic), at the rate of about 24 miles a day, towards the western coast of Australia; and since, notwithstanding the re duction of its temperature, the water which has circulated in the Indian Ocean is still much warmer than that which forms the general mass of the easterly drift, it is probably through this excess (imparting a corresponding excess of vapour to the atmosphere above, which is condensed again by contact with the colder land) that the fogs are generated, for which the islands that lie in the course of this flow are notorious. On arriving at the shores of Australia, this drift is divided by the south-west projection of its coast-line into two streams, one of which continues its eastward course along the southern coast, whilst the other, turning north wards, forms the West Australian current, of which the greater part, when it reaches the head-water of the southern equatorial current, is drawn into it, and thus completes the circulation of the southern Indian Ocean.
Between the parallel of 5, to which the influence of the monsoon winds extends, and that of 10 S., which is the usual northern limit of that of the southern trade, there is a "belt of calms," wherein there runs an equatorial counter current, which corresponds to that of the Atlantic, and is, like it, to be considered as a back-water flowing towards the source from which the currents to the north and south of it derive their supplies. (W. B. C. )
INDIANS, American. The application of the name Indians to the native peoples and tribes of the New World is an erroneous usage, originating in the belief of the Spanish discoverers of America that they had reached the eastern shores of Asiatic countries already partially known. As it happens, the name is now, even apart from the addition of American, customarily applied to the aborigines of the western hemisphere, while it is used with far less frequency as a collective name for the inhabitants of the great country of the East known from the remotest times as India.
Various questions in regard to the American Indians have been discussed in the article America. It is here intended to treat more particularly their ethnographical position, and to give what may be called a working classification of the races. This is followed by a separate notice of the present distribution and condition of the North American Indians.
It may be asserted with some confidence that there is nothing in the physical and mental condition of the aboriginal Americans which requires us to postulate for them a foreign origin. If man was evolved originally from several centres, America assuredly included one at least; if he sprang from a single pair, then we can even conceive that pair to have been first established in the New World, and the arguments brought forward in support of an Asiatic origin of the American would not lose their point if adduced in favour of an American origin of the Asiatic peoples.
Andreas Retzius, the founder of scientific craniology, arguing on insufficient materials, grouped all the American aborigines in two great divisions—(1) a western or highland, occupying the main ranges of the Rocky Mountains and Andes, with the intervening lands thence to the Pacific; and (2) an eastern, mainly lowland, whose domain stretched from the western uplands to the Atlantic seaboard. The former, being characterized by brachycephalous or round heads, he felt disposed to connect with the brachycephalous Mongolians and Malays of Asia and Australasia. The latter, being of a decided dolichocephalous or long-headed type, he traced to possible Berber and Guanche migrations from north-west Africa and the Canary Islands, doubtless because the historical arrival of the dolichocephalous Norsemen in the New World was of too recent date to serve his purpose. But Virchow (“Anthropologie Amerika's,” in Verhandlungen der Gesell. für Anthropologie, 1877, p. 144-56) has amply shown that this classification is untenable, and it will be seen further on that there are long and round-headed types often intermingled in every part of the continent. Virchow himself, while denying the claim of the American race to be considered autochthonous, declines to commit himself as to the probable regions whence they may have reached their present habitat. The theory of an Asiatic immigration via Behring Strait has been somewhat revived since ethnologists have, so to say, rediscovered the lost Tchuktchis of the north-east coast of Siberia through Nordenskjöld's Swedish polar expedition of 1878-9. These Tchuktchis are supposed to form the connecting link between the races of the two worlds, and the supposition is strengthened by the invention of an American branch of the tribe. Professor Nordenskjöld himself remarks that “this race, settled on the primeval route between the Old and the New World, bears an unmistakable stamp of the Mongols of Asia and Eskimo and Indians of America” (Petermann's Mittheilungen, 1879, p. 330). But Lieutenant Palander of the same expedition says that "they undoubtedly descend from the Greenland Eskimo" (ib.) which would at once deprive them of all value as a connecting link, while Peschel (Races of Man, p. 391) much more probably allies them to the Itelmes (Kamtchadales), the
- ↑ This is commonly termed the Mozambique current; but, as the usual southerly direction of the surface flow in the Mozambique Channel is liable to reversal with the change from the north-east to the south-west monsoon, or even under the influence of local winds, the term Natal current (suggested by Mr Laughton) seems decidedly pre ferable.
- ↑ Some very curious temperature phenomena are produced on the Agulhas bank by the splitting up of the cold and warm currents, which form distinct bands and strata that do not mix for some time.
