76 STEPPES AND DESERTS. 



the collection of so great an amount of orographic data in the 

 highlands of Asia, and more especially in the regions (hitherto 

 so little known in the west), north and south of the Celes- 

 tial mountains, between the In-schan, the mountain lake 

 Khuku-noor, and the banks of the Ili and the Tarim. 

 The three advantages I allude to are, the military expedi- 

 tions towards the west, (under the dynasties of Han and 

 Thang 122 years before our era, and again in the ninth 

 century when conquerors advanced as far as Ferghana and to 

 the borders of the Caspian), together with the more peaceful 

 conquests of Buddhistic pilgrims; the religious interest 

 attaching to certain lofty mountain summits on account of 

 sacrifices to be periodically offered there; and the early 

 and general use of the compass in giving the directions of 

 mountains and of rivers. The knowledge and use of 

 the " South pointing" of the magnetic needle twelve cen- 

 turies before our era, has given to the orographic and 

 hydrographic descriptions of countries by the Chinese, a 

 great superiority over the descriptions of the same kind 

 which Greek or Eoman writers have bequeathed to us, 

 and which are besides extremely few. The acute and 

 sagacious Strabo, was alike imperfectly acquainted with the 

 direction of the Pyrenees, and with those of the Alps and of the 

 Appennines. (Compare Strabo, lib. ii. p. 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-west 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 



