704 THIBET chains which connect the western extremities of these two great ranges separate Thibet from Cashmere. It appears now to be established beyond doubt that a third lofty and snow- capped chain intervenes between the Himalaya and the Kuen-lun, parallel with them, proba- bly a prolongation eastward of the Kara- korum mountains, under the name of Nian- tsin-tangla according to Ritter, and Tanla ac- cording to Hue. Hodgson calls it the Nyen- chhen-thangla range. It forms the northern boundary of Great Thibet, a region which ex- tends thence southward about 200 m. to the outer Himalaya overlooking India, and 750 m. from W. to E. along the basin of the Sanpo or upper course of the Brahmapootra. Western Thibet (Thib. Ari), in the widest sense, com- prises Ladakh (outside of the limits above sta- ted ; see LADAKH) and the lofty Himalaya re- gion about the sources of the Ganges and the Sutlej; while of eastern Thibet (Thib. Kam) little is known except that it is deeply indent- ed by the gorge-like valleys of the numer- ous great rivers which flow thence into China, Indo-China, and Burmah. In its main physi- cal features Thibet is a vast, arid, mountainous plateau, with an altitude seldom less than 10,- 000 ft. above the sea, except in the lowest val- leys, and over a great part of its area more than 14,000 ft. The northern portion of the country, between the Nyenchhen-thangla range and the Kuen-lun, consists of a series of lofty table lands, uncultivated, and inhabited only by nomads and robbers and the residents of the Buddhist monasteries, which are the only permanent dwellings met with in the region. Great Thibet is comparatively a cultivated country, of settled habitations, and contains the capital and principal cities ; but by far the largest part of its surface is occupied by vast grassy steppes, which afford abundant and val- uable pasture. In western Thibet the area capable of cultivation, or even habitable by man, is proportionately very small, owing to the exceedingly mountainous character of the region. Thibet has four systems of drainage. North of the great middle range of mountains, on the slopes of which are numerous glaciers, the drainage is wholly interior, the streams being received by the salt lakes which occupy some of the principal depressions. The most considerable of these is that known as Tengri- nor, or more properly Nam-cho, the Sky lake, 15,190 ft. above the ocean, about 50 m. long and from 16 to 35 m. wide. One of the trans- verse ridges extending northward from the Himalaya separates the southern part of the country into two basins, forming a watershed with the Indus and the Sutlej flowing off its W. slope, while its E. side sends the Brahma- pootra to water Great Thibet, which finally likewise makes its way down to the Indian plain. Near the great Kailas peak of the Him- alaya are Lakes Rhawan-rhad and Manasaro- war, out of which last pours the Sutlej ; and '.the remarkable ring-shaped lake of Palte, or Yamdok-cho, is about 35 m. S. W. of Lassa, in the valley of the Sanpo or Brahmapootra. Lake Koko-nor, in eastern Thibet, is near the head waters of the Hoang-ho. The nature of the rocks near the southern edge of the table land indicates that the Thibetan plateau must be of recent geological origin. The plains consist of horizontal gravel strata on which rest bowlders, and extensive fossil-bearing de- posits occur in the vicinity of the Himalayan range. In' the north metamorphic rocks alter- nate with beds of granite. Among the Nyen- chhen-thangla mountains are numerous hot springs, as well as geysers the waters of which freeze as they fall, forming lofty columns of ice. The climate in the higher districts is cold, dry, and almost rainless, and even the snow- fall is light. Timber never rots, but becomes so dry as to break, and the flesh of animals exposed to the air dries till it can readily be reduced to powder. The limit of perpetual snow is higher on the Thibetan than on the Indian side of the Himalaya, which is attrib- uted 'to the excessive dryness of the atmos- phere on the IsT. slope of the range. It is there 18,000 or 19,000 ft. above the sea, while in India it descends to 15,000 ft. During sum- mer the sky is clear and the atmosphere won- derfully transparent, but the plains are subject to violent winds and dust storms in winter, and the cold is intense. A warmer climate prevails in many of the valleys, where Euro- pean fruits and vegetables are raised. With the exception of the pasturage on the steppes, the vegetation of Thibet is scanty. Forest trees are unknown except in some of the mountainous districts, and in such as have been explored they consist principally of cedar and birch. In the warmer valleys the apple, fig, pomegranate, apricot, peach, vine, and sev- eral varieties of nuts are grown. Wheat and rice are cultivated sparingly, and some buck- wheat, but gray or black barley is the prin- cipal grain and the chief article of diet. The mineral productions comprise gold, silver, mer- cury, cinnabar, lead, iron, salt, and borax, as well as several kinds of precious stones, in- cluding lapis lazuli. Gold occurs, not only in the sands of some of the rivers but in many mines, of which perhaps the most productive are in western Thibet N. of the Kailas moun- tain. There are rich" silver mines in the neigh- borhood of Lassa, and although it is said that the authorities prohibit working them, large quantities of silver are constantly exported from Thibet into China. Salt, which is also an abundant article of export, is obtained by solar evaporation from the saline lakes. The number of animals is greater than might be expected from the scantiness of vegetation; among them are the tiger, ounce, lynx, wolf, fox, bear, buffalo, wild ox, wild goat, long- haired sheep, and yak, which abounds through- out Thibet. The shawl goat is the most im- portant of the domestic animals, and the musk deer the most valuable object of the chase.
