The Arctic Ocean--comprising the White, Barents, and Kara Seas--and the northern Pacific, that is the Seas of Bering, Okhotsk, and Japan, bound it on the north and east. The Baltic, with its two deep indentations, the Gulfs of Bothnia and Finland, limits it on the north-west; and two sinuous lines of frontier separate it respectively from Sweden and Norway on the north-west, and from Prussia, Austria and Roumania on the west. The southern frontier is still unsettled. In Asia beyond the Caspian, the southern boundary of the empire remains vague; the advance into the Turcoman Steppes and Afghan Turkestan, and on the Pamir plateau is still in progress. Bokhara and Khiva, though represented as vassal khanates, are in reality mere dependencies of Russia. An approximately settled frontier-line begins only farther east, where the Russian and Chinese empires meet on the borders of eastern Turkestan, Mongolia and Manchuria. Russia has no oceanic possessions, and has abandoned those she owned in the last century; her islands are mere appendages of the mainland to which they belong. Such are the Aland archipelago, Hochland, Tuetters, Dagoe and Osel in the Baltic Sea; Nova Zembla, with Kolgueff and Vaigatch, in the Barents Sea; the Solovetsky Islands in the White Sea; the New Siberian archipelago and the small group of the Medvyezhii Islands off the Siberian coast; the Commandor Islands off Kamchatka; the Shantar Islands and Saghalin in the Sea of Okhotsk. The Aleutian archipelago was sold to the United States in 1867, together with Alaska, and in 1874 the Kurile Islands were ceded to Japan. [ILLUSTRATION: ARCHANGEL.] A vast variety of physical features is obviously to be expected in a territory like this, which comprises on the one side the cotton and silk regions of Turkestan and Trans-caucasia, and on the other the moss and lichen-clothed Arctic _tundras_ and the Verkhoyansk Siberian pole of cold--the dry Transcaspian deserts and the regions watered by the monsoons on the coasts of the Sea of Japan. Still, if the border regions, that is, two narrow belts in the north and south, be left out of account, a striking uniformity of physical feature prevails. High plateaus, like those of Pamir (the "Roof of the World") or of Armenia, and high mountain chains like the snow-clad summits of the Caucasus, the Alay, the Thian-Shan, the Sayan, are met with only on the outskirts of the empire.