PHYSICAL FEATURES. 25 



The following are a few of the principal passes into Tibet : 

 Tsang Tsok Li (17,490 feet), M£na (17,890), Niti (16,628), Marchauk- 

 (19,000 about), Balch Dhura (17,590), Uttar Dhura (17,590), Dharma 

 (18,510), Langpaia Lek (Lankpya Lek of the map) (18,150), Lipu Lek 

 (Byans) (16,780), etc., etc. 



The rivers which drain the country examined by me belong to 



two systems: namely, to the Indus and the Gan- 

 ges. The provinces of Kumaun, Garhwal and 

 the native state of Tiri Garhwcil are drained by a series of big 

 streams which unitedly form the head-waters of the Ganges system, 

 whilst the high regions of the Hundes plateau of Tibet, Bisahir, Kun- 

 awa*r and Spiti belong to the Indus basin. These two systems are 

 separated by a watershed, which between the Nilang and Byans 

 areas coincides with the Northern range of the Central Himalayas. 

 The high peaks north-west of Nilang form a nucleus, from which 

 the line of water-parting between the two systems branches off 

 to south-west, dividing the Bagirathi from the Jumna valley. 



That portion of the Central Himalayas and of Hundes which be- 

 longs to the Indus system as far as it is describ- 

 ed in these pages, is drained by the Sutlej and 

 its numerous Tributaries. The Sutlej itself rises in the Manasarowar 

 lake district in Hundes, and flowing in a north-western direction 

 drains a large portion of the province of Hundes, finally entering the 

 Himalayas by a deep V-shaped valley near Shipki, from whence it 

 traverses the entire width of the Himalayan ranges. In Hundes itself 

 numerous smaller streams join it from both sides ; they and the Sutlej 

 itself have eroded deep troughs and occasionally narrow gorges in 

 the young-tertiary deposits which form the high plateau of this 

 part of Tibet. That of the Sutlej itself is fully 1,500 to 2,000 

 feet below the level of the plateau, which varies from 15,000 feet sea- 

 level near the southern margin to about 13,000 to 14,000 near the 

 centre of the high plain. In this deep V-shaped channel, or in that 

 of its tributaries, nearly all the permanently inhabited places in 

 Hundes are situated ; so, for instance, Kyunglung, Dongpu, Dapa*, 



( 25 ) 



