On the Pamirs Russia has since 1885 been conterminous with British India (Kashmir); but the boundary then swings away N. round Chinese Turkestan and the N. side of Mongolia, and, since 1904-5, it has skirted the N. of Manchuria, being separated from it by the river Amur. As thus traced, the boundary in Central Asia includes the two khanates of Bokhara and Khiva, which, though nominally protected states, are to all intents and purposes integral parts of the Russian empire. But it excludes Manchuria, with the Liao-tung peninsula and Port Arthur, upon which Russia only placed her grasp in 1898-99, a grasp which she was compelled by Japan to release after the war of 1904-5. The total length of the frontier line of the Russian empire by land is 2800 m. in Europe, and nearly Io,000 m. in Asia, and by sea over r1,000 m. in Europe and between Ig,000 and 20,000 M. in Asia. Russia has no oceanic possessions; her islands are all appendages of the mainland to which they belong. Such Islands. are Karlo, East Kvarken, the Aland archipelago, Dago, and Osel or Oesel in the Baltic Sea; Novaya Zemlya, with Kolguyev and Vaigach, in the Barents Sea; the Solovetski Islands in the White Sea; the. New Siberian archipelago, Wrangel Land and Bear Islands, off the Siberian coast; the Commander Islands off Kamchatka; the Shantar Islands and the N. of Sakhalin in the Sea of Okhotsk. The Aleutian archipelago was sold to the United States in 1867, together with Alaska, and in 1875 the Kurile Islands were ceded to Japan. If the border regions, that is, two narrow belts, on the N. and S., be left out of account, a striking uniformity of physical Leading feature prevails throughout the whole vast extent physical of the Russian empire. High plateaus like that of features. Pamir (the " Roof of the World ") and Armenia, and lofty mountain chains like the snow-clad Caucasus, the Alai, the Tian-shan, the Sayan Mountains, exist only on the out-skirts of the empire. Viewed broadly, the Russian empire may be said to occupy the territories to the N.W. of the great plateau formation Plateau of the old continent—the backbone of Asia—which formation stretches with decreasing altitude and width from 0' Asia. the high tableland of Tibet and Pamir to the lower plateaus of Mongolia, and thence N.E. through the Vitimr.egion to the farthest extremity of Asia. Thus it consists of the immense plains and flat lands which extend between the plateau formation and the Arctic Ocean, including the series of parallel chains and hilly spurs which skirt the former region on the N.W. And it is only to the E. of Lake Baikal that it climbs up on to the plateau, from which it descends again before it reaches the Pacific. This plateau formation—the oldest geological continent of Asia—being unfit for agriculture and for the most part unsuited for permanent settlement, while its oceanic slopes have from the dawn of history been occupied by a relatively dense population, long pre-vented Slav colonization from reaching the Pacific.