BOR'NEO (corrupted from Brunai, Malay Blend, Burnt, a district, the island having no comprehensive native name, though sometimes called Palo Kalamantin., after one of the native fruits). The fifth largest island in the world, only Australia, (lreenland, Bailin Land, and New Guinea or Papua exceeding it in area (Map: East Indies, D 4). It is situated in the East Indian Archipelago and extends from just north of latitude 7° N. to 4° 10' S., and from longi tude 108° 53' to 119° 22' E. It is bounded on the north by the China and Sulu seas, the latter separating it from the Philippine Islands; on the east by the Celebes Sea and Strait of Macassar, which separate it from Celebes: on the south by the Java Sea, which separates it from the island of Java; and on the west by the southern part of the South China Sea, which separates it from Malacca and Sumatra, and by Karimata or Billi ton Strait. It is 850 miles long and 000 miles wide in the broadest part, and has an area of about 290,000 square miles, with a population eunjectured to be nearly 2,000,000. The interior nas been but partially explored, much of the coun try being one vast, almost impenetrable jungle.
A little north of the middle of the island there is a central highland region called the 31adei _Mountains, from which stretch out in different directions mountain ranges that in most eases continue to the coast, and which include between them low valleys. A mountain range which, with a certain discontinuity, extends toward the northeast, divides the northern part of the island into eastern and western seetions and culminates near the extreme north in the isolated peak Kini Bain, which attains an alti tude of 13,700 feet. Other ranges diverge, one toward the west (the Klinkang Mountains); another range toward the southwest. which, with that toward the northeast, forms a central chain; another range toward the southeast, which in approaching the coast bends toward the south and continues to the extreme southeastern cor ner of Borneo; and still another range toward the east. These mountain ranges do nut appear to have had names assigned to them as complete chains, although the different portions have dis tinctive local names. A number of the summits
rise to 7000-9000 feet. In the extreme west are a few small volcanic cones. Between the two main ranges, which diverge to the west and southwest, lies the valley of the Kapu which river flows southwest to the west coast, forming there a broad delta after the manner of several of the Borneo rivers. The region on the north of the Klinkang and \ladei mountains is drained chiefly toward the west by the Batang Lnpar, Rejang, Barram Limbang. and other rivers. The northeast section is drained toward the east by the Koti, Segal, Kajan, and other rivers. The whole southern lowland region is drained toward the south by the Barito (which is nearly 600 miles in length), Little and Great Dyak, Ka tingan, Pembuan, Kota•ingin, Djellei, and other rivers. Many of the rivers are navigable. but only for small boats, as most of the river mouths are closed by bars which prevent the en trance of sea-going vessels. The rivers are subject to frequent floods at all seasons, and to wide ex pansion during the rainy season. The southern and eastern sections possess extended areas of lowland, which become flooded during the rainy season and form great lakes, and in the dry sea son are intersected by numerous watercourses of both river and canal or ditch-like character.
The coast of Borneo is, in the main. indented only by open bays. It has few islands, the chief of which are Labium on the northwest coast, Bangney on the north coast, Na nokong on the northeast coast, Laut on the southeast coast, and \laivang on the southwest coast.
The geological formations are Tertiary and post-Tertiary, except in the central and western mountains, which are pre-Tertiary. and consist largely of Devonian and Carboniferous sehists and slates. Economically. the most important formations are the coal deposits of the Tertiary period. and they show the remains and much of the detailed structure of the luxuriant vegeta tion of this period. The chief products of the rich mineral deposits are gold, diamonds. silver, platinum, mercury, tin, and antimony, to which must he added petroleum, sulphur. rock salt, marble. rock crystal, and porcelain-clay. Most of the streams appear to be auriferous.