OCR Text |
Show ANNOTATIO~S AND ADDITIONS. 77 directions of mountains and of rivers. The knowledge and use of the outh pointing" of the magnetic needle twelve centuries before our era, has given to the orographic and hydrographic descriptions of countrie by the Chinese, a great superiority over the descriptions of the same kind which Greek or Roman writers have bequeathed to us, and which are besides extremely few. The acute and sagacion Strabo was alike imperfectly acquainted with the direction of the Pyrenees, and with those of the Alps and of the Apennines. (Compare Strabo, lib. ii. pp. 71 and 128; lib. iii. p. 137; lib. iv. p. 199 and 202; lib. v. p. 211, Casaub.) To the lowlands belong almost the whole of Northern Asia to the north-we t of the volcanic chain of the Thian-schan ;- the Steppes to the north of the Altai and of the Sayan chain ;- the countries which extend from the mountains of Bolor, or Bulyt-Tagh, ("cloud mountains" in the Uigurian dialect,) which follow a north and south direction, and from the upper Oxus, (whose sources were found by the Buddhistic pilgrims Hiuen-thsang and Song-yun in 518 and 629, by Marco Polo in 1277, and by Lieutenant Wood in 1838, in the Pamer Lake, Sir-i-kol, Lake Victoria,) towards the Caspian; and from Tenghir or the Balkhash Lake through the Kirghis Steppe, towards the sea of Aral and the Southern extremity of the Ural mountains. As compared with high plains of 6000 to 10,000 feet above the level of the sea, it may be well permitted to use the expressions of "lowlands" for flats of little more than 200 to 1200 feet of elevation. The lowest of the last two numbers corresponds nearly to the altitude of the town of Mannheim, and the highest to that of Geneva and Tubingen. If the word plateau, so often misemployed in modern works on Geography, is to have its use extended to elevations which hardly present any sensible difference in climate and vegetation, the indefiniteness of the expressions "highlands and lowlands," which are only relative terms, will deprive physical geography of the means of expressing the idea of the connection between elevation and climate, between the profile or relief of the ground and the decrease of temperature. When I found myself in Chinese Dzungarei, between the boundary of Siberia and Lake Dsaisang, at an equal distance from the Icy Sea and from the mouth of the Ganges, I might well consider myself in Central Asia. 7* |