2 54 The National Geographic Magazine 



Tracts with no outlet seawards. 

 ^— ^^—^ &f>K> Miles. 



Arid Regions and Closed Basin of Asia 



Courtesy of Messrs. D. Appleton & Co. 



to establish connection with the sea. 

 The streams on one side or the other 

 eat back through the watershed, ' 'steal' ' 

 the source of an earlier and less vigor- 

 ous stream, and bring about that con- 

 tinuous drainage across the previous 

 dividing line which is the mark of so 

 much of our Appalachian region . Noth- 

 ing of this kind has happened with this 

 closed basin, which from the earliest his- 

 tory has remained closed. The greater 

 streams of Asia, like the Indus and the 

 Ganges, have eaten longitudinally in 

 the folds of the great sj^stem in which 

 they sprang, and have not cut across the 

 watershed. The different conditions of 

 China from those of India appear in large 

 measure due, however, to a somewhat 

 different action of the streams there, 

 though this awaits further investiga- 

 tion. The great curve of the Hoang- 

 Ho and sundry conditions of the upper 

 Yangtze Kiang indicate the coalescence 



of valleys previously sepa- 

 rate. 



The eastern part of this en- 

 closed area, the Great Plain of 

 Turkestan, extends to a level 

 below the surface of the ocean ; 

 but all the three parts, the 

 elevated plateau of Tibet, the 

 less elevated area of Chinese 

 Turkestan, and the plains of 

 the Khanates, constitute to- 

 gether a great block interfer- 

 ing with free communication 

 between the two city centers 

 of Asia and the successive city 

 centers of Europe, first south 

 and then north of the Alps. 

 Over all this area a dense pop- 

 ulation has never been possi- 

 ble. Only at points where 

 irrigation is feasible has the 

 population ever reached a high 

 degree of civilization in tracts 

 essentially insular in their 

 character, cut off by oceans of 

 desert, and able to develop 

 insular cultures in the midst 

 of a continental area. Two great high- 

 ways extend across this enclosed basin. 

 Of the two areas on each side which 

 are open to the ocean, connecting the 

 Eurasian centers of population, the one 

 to the north is closed by cold. 



THE LINK REGION 



There remains, therefore, in the great • 

 land stretch which apparently connects 

 the different civilizations of the Eurasian 

 sj^stem only the narrow strip of ocean- 

 drained lands which extends from the 

 Indus to Asia Minor. This constitutes 

 the natural highway of the Eurasian 

 system. It is the link land of the con- 

 tinent. Its history has had an internal 

 development. Its external relations, 

 however, the growth of its dynasties, the 

 course of its culture, the development of 

 its wealth, and the channels of its trade 

 have throughout this entire region — 



