SIIIIAT'RA (called by the Arabians Srinme or Srimata, " the happy," whence its present name), the most westerly of the Sunda islands, lies s. of the Malay peninsula, from which it is separated by the strait of Malacca. Lat. between 5°45' n. and 5° 50' south. It is 1040 m. long and 266 in. in extreme breadth; area, 168,000 sq.m.; pop. including that of the adjacent isles, 5,000,000, about two-thirds of whom are directly or indirectly under Netherlands rule. The Europeans in 1873 numbered 2,654, not including the army in Atcheen.
Physical Barisan mountains run throughout its entire length, varying in altitude from 1550 ft. in the s.w. to 6,000 under the equator. Lofty cones, of which about 20 are volcanoes, attain to from 6,000 to upward of 10,000 feet. Another series of mountains runs parallel with the Barisan, lofty plateaux of great extent linking them together at various points. On the w. coast, a few m. of low land lie between the moun tains and the sea, in some parts spurs reaching the shore in beetling cliffs. Wide alluvial plains, covered with dense jungle and forest, through which the rivers run sluggishly, forming deltas at their mouths, stretch along the n.e. coast; while the tidal action is eat ing into the w. coast, new ground is forming on the east.
Extensive valleys lie between the mountain chains. Several beautiful lakes are scat tered over the interior. The largest is lake Singkarah or Samawang, in upper Padang, 17 m. long and 6 broad. It is 1167 ft. above the sea, and discharges its waters by the Ombilin, which flowing toward the e. coast, becomes the Indragiri.
The mountain systems are of trachyte, granite, limestone, red sandstone, and a wide spread conglomerate composed of granitic and quartzose particles, the hollows in many places being filled with lava. Sienite, porphyry, serpentine, jasper, basalt, and tufa occur. Tertiary deposits are found in the valleys, and in some parts of the coasts a rich vegetable mold rests on beds of red and gray clay, or on coralline lime stone. Potter's clays are met with, and gold is widely diffused. Coal, iron-ore, copper, sulphur, lead, silver, saltpeter, alum, naptha, etc., abound.
Rivers.—Sumatra has many rivers, the most important being the Talang-Bawang; the Masi, or river of Palembang; the Djambi, Indragiri, and Siak, on the e. ; the Sing
kel, Tabujong, Indrapura, Mao-3loko, Bencoolen, and Padang Gutjie on the west. The capes and bays are numerous, the bay of Tapanuli being capable of containing a large fleet. A chain of islands lies parallel to Sumatra in the Indian sea. The most important are—Babi or Si Maltz, Nias (q.v.), the Bata islands, North Pora, Coco island, South Pora, North Pagel, and South Pagei. To the s.e. lies Banca, rich in tin, produ cing also iron, lead, silver, copper, arsenic, and amber.
climate of Sumatra is moderately healthy, especially on the e. coast. In Tapanali, however, are large marshes, inducing intermittent and typhoidal fevers, dysentery, and other diseases. A slight increase of temperature takes place from October to March, the minimum being in May. Except in the highlands of the interior, where it is cool, the thermometer ranges from 70° Fahr., at sunrise, to 94° at 2 P.M. The monsoons are irregular, and rain falls during all the months, though the quantity in October and December is double that in February and June.
Flora.—Sumatra has many fine species of timber trees—as the djati (tectona grandis), the marls, a hard and heavy wood, ebony, iron-wood, etc. The magnificent dryoba lanops camphora, and other resin-producing trees, are abundant. Several species of fig, the urceola elastica, from which caoutchouc is obtained, and the gutta-percha tree (isonandra gutta), axe numerous. In the villages the bombax, or silk-cotton tree, forms a shady resting-place at neon. The lovely cinnamomum cassia, the melaleuca leucaden dron, which yields the medicinal cajeput oil, the satin-wood (chloroxylon sicietenia), the gigantic reed (calaraus draw), from the ripe fruit of which the dragon-blood gum exudes, and a great variety of palms, form part of the botanical wealth of island. Flowering plants and shrubs are numerous, and countless. parasites garland the forest trees with flowers of every hue. The most curious of these is the rajjlesia (q.v.), which, clinging to the bark of large trees, spreads out the largest known flower, with a' calyx 3 ft. in diameter and 9 in. deep, and capable of containing 2 gallons of fluid.