TIBERIUS. 267 TIBET. When the death of Augustus occurred. August 19, 14, Tiberius was ou liis way to lllyricum. He was summoned liome by his mother, and at once assumed control of the Pmpire. Despite his execution of Postumus Agrippa, the grandson of Aiigustus, Ids reign was at first beneticent. Grad- ually, however, a change took place in Tiberius. He minimizeil the power of the jieople. and trans- ferred the election of magistrates from them to the senate. At the same time he watched w'ith suspicion the increasing popularity of Germani- cus Caesar (q.v.), his nephew. In 19 Gcrmanicus died, poisoned, if the reports current at the time may be believed, at the instigation of his uncle. About this time the evil genius of the reign of Tiberius, .-Elius Sejanus (q.v.), gained his as- cendency over the Emperor. Under his influence a system of espionage was instituted which doomed all who in any way opposed Tiberius. Freedom was abolished in Rome, the senate was demoralized, and the Emperor sank to the level of a cruel and ruthless tyrant. In 23 Sejanus abetted the murder of the only son of Tiberius, Drusus Caesar (q.v.). Three years later the Emperor left Rome with Sejanus, going first to Campania and in 27 to Capri, where he re- mained till his death. In 29 Livia Drusilla died, thus removing one of the last barriers to the complete degeneration of her son. Two years later Tiberius learned of the treachery and ambition of Sejanus, who was put to death, only to be replaced by Macro, as corrupt as his predecessor. In 37 Tiberius died, smothered, though already on his death-bed, by Macro, and was succeeded by Caligula (q.v.). The reign of Tiberius was beneficial to the Empire at large, and the provinces especially flourished under his sway. Only in Rome, and only where liis personal interests were at stake, was he merciless. The writings of Tiberius have been lost. His style is said to have been obscure, archaic, and affected. He wrote a brief autobiography, a lyric on the death of Lucius C»sar, and a number of Greek poems. Consult: Ihne, Plea for the Emperor Tihcrius (London, 1853) ; Pasch, Zur Kritik dcr Ge- schichte des Kaisers Tiheriiis (Altcnburg, 1800) ; Freytag. Tiberius iind Taeitus (Berlin. 1870); Stahr, Tiberius' Leben, liegierunq, Charakter (2d ed., ib., 1873); Tu.xen, Kejser Tiberius (Copenhagen, 1896) ; Baring-Gould, Tragedy of the Ccesars (London, 1892). TIBET, or THIBET, til/et or tl-bet'. A re- gion of Central Asia, forming part of the Chinese Empire. It is bordered on tlie north and east by Chinese territory', and on the west and soutli by Kashmir, Nepal, Bhutan, Sikkim, Assam, and Burma. Tibet is one of the least known parts of the world, foreign travel and exploration being forbidden in accordance with Chinese policy. There is some uncertainty even as to its exact boundaries and extent. Politically three distinct regions included within its wide limits must be eliminated: (1) 'Little Tiliet.' between 74° and 79° east longitude, now included in Kashmir, and composed of Baltistan and Ladakh (qq.v.) ; (2) and (3) the two regions known as Ku-ku-nor and the Ts'aidam, or Ch'ai- dam, lying south of the Nan-shan, east of the Altin-tagh, and north of the curve formed by the eastern and southeastern extensions of the Vol. XIX.— 18. Kuenlun system, bearing the names of Akka, Tolai, Angirteksliia, Barklian-Bhuba, Shuga, etc. Physical Feature.s. Tibet presents two dis- tinct physical divisions: (1) A region of lakes in tile north, and (2) a region of rivers in the south and east. The first, occupying the greater portion of the western half of the country, is known as the Chang Tang or 'Northern Plain.' It is an arid treeless and shrubless solitude, with rounded hills and broad flat valleys between them, and a number of sharply defined mountain ridges rising several thousand feet above the plain. It has an average elevation of from 14,000 to 10,000 feet, falls away gradually to the east and south, and is dotted with lakes — mostly salt, some of them of considerable size. The more or less parallel mountain ridges, to- gether W'ith their separate valleys, lie buried beneath a vast accumulation of mountain debris, giving the surface the aspect of a plateau of uplift, or of one of tectonic construction. The streams terminate in salt lakes, which give unmistakable evidence of gradual desiccation. Large stretches toward the Kuenlun are uninhabitable, and are abandoned to the wild beasts. In the southern zone, between the parallels of 32° and 33° north, a lofty range reaches as far east as 90° 25' — the Nin-chin Tang-la, the highest peak of which has an alti- tude of 24,153 feet, the Goring-la pass having an elevation of 19,587 feet. From 33° 50' north toward the Kuenlun there are ranges of extinct volcanoes with altitudes of 20,000 feet. One of the best known lakes of this region is the Pangong-tso, 13,930 feet aliove sea-level, partly in Ladakh (about latitude 34° north and longitude 79° east). This inhospitable region is bordered on the east and south by the region of rivers, which is also a region of snow and ice-covered moun- tains and deep ravines. Its eastern section covers the whole eastern half of the country, stretching from about 90° east to China. It "is almost entirely occupied by a succession of more or less wooded but lofty and steep moimtains, with a general north to south trend, cut into deep narrow gorges, in which flow the rapid streams of melted snow which unite to form the upper courses of the great rivers which are known in their lower courses as the Hoangho, the Yang-tse-kiang, the Mekong, and the Sal- win (qq.v.). The southern section of this river region lies to the south of the Chang-tang and extends from the Nin-chin Tang-la north of Lhasa, the capital, to the great South Chain, and is overlooked by Mount Everest, the highest peak of the Himalaya. Its mountains have a southeast and east trend, with many lateral intersecting ranges and spurs, which give direction to its numerous streams. In it are found the sources of three important rivers — the Indus and the Sutlej (qq.v), which rise in the Gang-ni or Kailas Mountains in tile west and flow through India, and the Brahmaputra, which, under the name of Yaru-Tsangpo, rises farther east .in the Mariam-la Mountains. The principal lakes of this region are the Sacred Manasarowar, near the sources of the Indus and the Sutlej, and 'Scorpion Lake,' the Yamdok or Palti, south of Lhasa, with a cir- cuit of 45 miles. Here are found the bulk of
