being around Ubsanor. Dr. A. H. Keane in his work on Asia gives the mean elevation as "probably not more than 2000 feet," to the western portion. Apart from some 7000 square miles around Ubsanor, the Encyclopædia Britannica states that the altitude of North-Western Mongolia ranges from 3000 to 4500 feet even in the river valleys and lower plains.
The chief mountains of this portion of Mongolia are, on the north-west the Russian Altai; on the north-east the Western Sayans; on the south-west the Ektag- Altai, which form a true border range facing the Zungarian depression; and the Kentai on the south-east, which separate the higher terraces of North-Western Mongolia from the Lower Gobi. North-Western Mongolia is described as "a massive swelling of the earth's crust, representing the northern counterpart of the plateau of Tibet." It is well watered, and has a good many lakes, "the desiccating remains of much larger basins."
Its chief rivers are the Jabkan, the Yenisei, and the Selenga, the Orkhon, and the Tola, on which Urga stands. Its chief lakes are the Ubsa, one of the largest in the Empire, being 1200 square miles in extent, the Kobdo and Kara-ussa lakes. Owing to its high altitude North-Western Mongolia is very cold in winter. The yearly rainfall in Urga is only 9½ inches. The temperature varies from —18° Fahr. in January to 64° in July. The chief towns are Urga, Uliassutai, and Kobdo. The chief occupation is cattle-breeding, with the export of furs and the transport of goods.
The Gobi.—The Mongolian word "Gobi" and the Chinese "Shamo" mean "sandy desert." Its characteristic is an open, flat and undulating plain "covered with a hard coating of gravel from which the wind has swept the lighter particles of mud or sand." Richthofen accepts the Chinese term of Han-hai or Dry-sea, supposing this region to be the bed of a former Central-Asia Mediterranean, but two professional geologists, Bogdanovitch and Obrucheff, after traversing some 20,000 miles of the plain, have discovered only one
