Under the designation Plain of the Oxus is embraced the level tract extending from the base of the mountains east of Kunhi (68' E.long.) to the Caspian, and from the shores of the Aral to tho south of Balkh. From the junction of the river of Kunduz with the Amu-Deria the latter river maintains a generally north-west direction till it loses itself in the sea or lake called Aral. Below the junction of the Kunduz, the Amu receives no affluents of any magnitude. Wood forded the Amu at Jan-Kila, a short way above its junction with the Kokcha. [Ilanixsitte. A man on foot could not have forded the river here; and fewer than three horses abreast could with difficulty stem the current. At the ferry between Balkh and Kurshi, Burnes found the Amu about 800 yards across, with an average depth of 20 feet and a current of 31j miles an hour. At Charjui, on the road from Bokhara to Meshed, he found the river 650 yards broad, and in some places 25 and 29 feet deep. Kunduz is 498 feet above the sea. A barometrical levelling by Russian officers, in the winter of 1825, gives the height of Lake Aral above the Caspian 117 feet. [Aa&L; Cigna's.] From the banks of the Amu to the Elborz or, the south west, and to tho snowy mountains east of Kurshi on the east, extends an immense plain, the elevation of which, towards its southern extre mity, is at Balkh 1718 feet above the level of the sea, and at Khulm, 1437 feet. At Bokhara its elevation is 1201 feet. The northern boundary of this plain is formed by a ridge of high broken ground north of Bokhara, which extends from the eastern mountains to the Amu above Khiva ; west of the Amu it is bounded to the north by the Aral and by the abrupt termination of the Ust-Urt, a high table land rising precipitously from the shores of the Aral and the Caspian, to an average level of nearly 600 feet above the latter, occupying the whole breadth of 138 miles between the seas, and extending south of the southern termination of the Aral, almost to 41' N. lat. The central plain maintains a considerable elevation from Sherrukha to the base of the Ust-Urt, and the maximum depression of tho level of the basin of the Caspian extends a very little way to the eastward.
The wide tract extending from the shores of the Aral to the Caspian, and the Russian and Chinese frontiers, is known as the Steppe of the Kirghiz Tartars. From Orsk to Uralek the course of the Ural River Is nearly east and west, and sinks from 582 feet to about 200 feet above the level of the sea. From Orak to Guriev, near the Caspian, the Ural runs nearly south, and sinks to 140 feet above the sea at Kalmukomb, and to nearly 82 feet at Guriev. The steppe on the south bank of the Uml, between Orak and Umiak, appears to rise immediately to an average elevation of 500 to 800 feet. Mount Airuk, 224 miles S.E. from Orenburg, the highest summit of the Menge* Hills, rises 800 to 1000 feet above tho level of the steppe. From this culminating point the ground slopes, dill in a south-east direction, gradually down to the level of the And, a distance of 300 miles. To the south-west the ground sinks gradually to the level of the Ust-Urt. The Emba (which flows south-west to the Caspian), the Uil (which flows west till it is lost in the sands east of the Lower Ural), the Khobda and llek (which flow to the north of west, and after uniting their streams fall into the Ural midway between Uralsk and Orenburg), and the Or (which flowing to the east of north, joins the Ural at Orak), all rise on the sides of Mount Airuk. The eastern base of the Mongojar range is washed by the Irghiz, which, rising in an undulating plain south of the sources of the Tobol, nearly in 51° N. lat., flows to the south and loses itself in a chain of lakes called Ak-Sakal, about 60 miles north-east of the north-eastern corner of Lake Aral. From the sources of the Irghiz and Tobol, about 60° E. long., to those of the Turghai, about 3 degrees to the eastward, there extends a plain considerably elevated above the level of the ocean, but con siderably depressed below the hilly countries to the east and west of it, covered with a multitude of salt-lakes, and sending its waters southward to Lake Ak-Sakal, northward to the Tobol and Ishim, both affiuenta of tho Irtiah. The numerous streams which unite to form the Turghai rise about 64° E. long., over a range of country extending from about 49' to 52' N. and convergiug iuto one main stream flow westward to the LTIkialc, which coming from the.north joins the Irghiz near its termination in Ak-Sakal. Tho course of tho upper
rivulets of the Turghai appears to form the western termination of it belt of high land which extends iu a north-western direction, parallel to the course of the Irtish, between Ust-Bukbtarminsk and Omsk, from the high lands between the Nor-Saisan and Tarbagatai, about 85' E. long., to the meridian of 64° E. From its outlying hills on the north, about 100 miles from the banks of the Irtish, to its southern base, this high Land must have a horizontal breadth of nearly 180 miles. Its central ridges reach an estimated elevation of at least 5000 to 6000 feet above the sea. To the north it sends out the Ishiui (which joins the Irtish), the Nura (south-west of the lehim), the Selenta, Tanta, Chanderli, and other rivers to the eastward, which lose themselves in the steppe lakes before they reach the Irtish. To tho south this high land sends forth the Aingue, the Jurgutu, and some other rivers which fall into the Lake Balkash on the Chinese frontier; and the Sar1•Su and the Kongur, which meet about 47° N. lat., 67' E. long., and from their point of junction flow south-west till they are lost in brackish lakes about 40 and 50 miles from the Sir-Deria. The Tahui, which is believed to issue from Lake Issi-Kol, at the northern base of the Thian-Shan range, about 42° N. lat., 81° E. long., flows in a north-west direction till it is lost in a salt-lake a little to the south of that which receives tho united streams of the Kongur and Sari-Su. The hills south of Issi-Kol extend westward from the meridian of that lake to the Sir-Deria, about 69° E. long. The Sir-Deria flows at their southern base to 69' E. long., then turns and flows past their termination to the north till it reaches within a degree of latitude of the lakes in which the Tshui terminates; hence it bends away to the west and flows to Lake Aral in 61° E. long. The apex of the delta of the Sir-Dena is not less than 5 degrees to the east of the shores of the Aral; the most northerly branch joins that lake not far from its north-east angle, about 46° N. lat., and the most southerly near its south-east angle, about 431j° N. lat. The mouu tains which intervene between the upper valley of the Sir-Dcria and the valley of Samarcand, and the hills which extend from their western termination to the Amu, form the extreme southern boundary of the Kirghiz Steppe, between 42* and 43° N. lat. Humboldt esti mates the elevation of Lake Balkash as not more than 800 feet above the ocean. The Aral is about 30 feet above the level of the Black Sm. (Caarierv.) The extensive range of country which lies east of the great elevation of Pamir, has been called by recent geographers Chinese Turkistan or Tartary. The Thian-Shan extends along its northern side, from the junction of the range with Pamir to its junction with the high desert plain of the Oobi, and tho high laud of Tibet along its southern side. Lop-Nor appears to form its eastern boundary. Kash gar and Yarkand stand on a plain much depressed below the level of the highlands to the north, south, and west of thew, in 39° 25' N. lat., 73" 56' E. long. ; Yarkand in 38° 19' N. lat., 76° 18' E. long. A river flows past Kashgar, formed by two streams, one of which comes from the pass of Karakorum on the road to Latlak ; the other from a range of hills at the cast end of Sir-i-Kol. A river flows past Yarkand, formed by tho junction of two streams, one of which comes from tho Terek Pass, on the road to Kokand ; tho other from a lake on the high plain of Pamir, situated between the Terek Pass and Ushi is situated among the hills at the base of the Thian Shan, in 41* 3' N. lat., 78° E. long ; Khotan, at the base of the high land of Tibet, about 37' N. lat., 80° E. long. The rivers of Yarkand and Kashgar unite about 40° N. lat., 80° E. long., and receive near their junction rivers from Ushl and Khotan. The united stream flows eastward to the Lop-Nor (41° N. lat., 89° E. long.), receiving on the way affluents on its north bank from Kukhi (41' 37' N. let., 82' 50' E. long.), and from Kharashar (42° 10' N. lat., 87' 10' E. long.). Tho river formed by the uniou of the rivers of Khotan, Yarkand, Kash gar, and Ushi, flows close to the hills at the base of Thian-Shan. East of Khotan the country is represented as a saud-waste, and the same account is given of the country mat of Lop-Nor. The country Lop-Nor and the upper Hoang-ho attains to a considerable elevation.