4 STEPPES AND DESERTS. 



Desert must be regarded as uninhabitable by man. The 

 more civilised nations who dwell on its borders only venture 

 to enter it periodically. By trading routes, which have 

 remained unaltered for thousands of years, caravans traverse 

 the long distance from Tafilet to Timbuctoo, and from 

 Moorzouk to "Bornou; adventurous undertakings, the possi- 

 bility of which depends upon the existence of the camel, 

 the " ship of the desert/' ( 9 ) as it is called in the traditionary 

 language of the eastern world. 



These African plains occupy an extent nearly three times 

 as great as that of the neighbouring Mediterranean sea. 

 They are situated partly within, and partly in the vicinity 

 of the tropics ; and on this situation their peculiar character 

 depends. In the eastern part of the old continent, the same 

 geognostic phenomenon occurs in the temperate zone. On 

 the plateaux of central Asia, between the gold mountains or 

 the Altai and the Kuen-lun, ( 10 ) from the Chinese wall to 

 beyond the Celestial mountains, and towards the sea of Aral, 

 there extend, through a length of many thousand miles, the 

 most vast, if not the most elevated, Steppes on the surface 

 of the globe. I have myself had the opportunity, fully 

 thirty years after my South American journey, of visiting a 

 portion of them ; namely, the Calmuck Kirghis Steppes be- 

 tween the Don, the Volga, the Caspian, and the Chinese 

 lake Dsaisang, being an extent of almost 2800 geographical 

 miles. 



These Asiatic Steppes, which are sometimes hilly and 

 sometimes interrupted by pine forests, possess (dispersed 

 over tnem in groups) a far more varied vegetation than that 



