They have few wants and derive a livelihood principally from gathering and bartering shells, pearls, cured _thadecon_, and nests of the sea-swallow (Collocalia). Within depths of six or eight fathoms they are fairly good divers, both the men and the women, but their physical endurance is slight. Their trade is mostly with Chinese merchants who visit them in small vessels. No information exists as to when the Selangs first found profit in searching for pearls; but it was probably many centuries ago, and for a long time they made contributions of them to the Buddhist rulers of Burma. Shortly after the acquisition of Mergui Archipelago in 1826, representatives of the British government brought experienced divers from southern India to examine more fully the resources which the Selangs had made known; but as only seed-pearls were secured, the government concluded that they would yield an insignificant revenue, and the attempt to develop these resources was given up.[164] However, the Selangs continued to fish in their primitive fashion; and as the market for the shell developed, the profits increased. But their wants were easily appeased, and the increased profits were counterbalanced by decreased activities. Old traders among the islands tell of the opportunities of those days when choice pearls could be obtained for a pinch of opium or for a few ounces of tobacco. Far from the highways of the world, the Selangs remained undisturbed in their beautiful seas until nearly twenty years ago. Meanwhile, 800 miles distant, Singapore had arisen from a desert shore to the rank of a great seaport, and the headquarters for the pearl fishery of the Malay Archipelago and of the northwestern coast of Australia. In this fishery the vessels were well equipped and depended on the use of diving apparatus rather than on nude divers. Beginning about 1888, some of these vessels made occasional visits to the Mergui pearl-oyster reefs, and usually with very profitable results. This was the first instance in which diving apparatus was successfully introduced on any part of the Asiatic coast from the Red Sea to Malacca Strait. So great was the profit that nearly every one on the lower coast of Burma with sufficient capital or credit hastened to obtain a boat and diving equipment. The success of some of these early ventures was remarkable, single pearls worth $3000, $5000, and even $10,000 each being secured. The reefs in the shoal waters were rapidly depleted, to the great disadvantage of the nude Selangs, who can do little in deep water.