国立情報学研究所 - ディジタル・シルクロード・プロジェクト
『東洋文庫所蔵』貴重書デジタルアーカイブ

258

THE SOURCE OF THE BRAHMAPUTRA.

at many places. It is not the amount of water which causes difficulties, for the Tsangpo is fordable even below Tuksum; it is on account of the blocks and boulders

in the bed.

I cannot be responsible for the correctness of the following geographical information given by my guides, but as they proved to be very reliable in everything else I think it worth while to relate their description of a completely unknown part of the Himalayas. They asserted that somewhere to the S.W. was a snow-covered pass, Tabsi, with a difficult and hardly ever used road leading across the high mountains to the valley of Map-chu or Kauriala. Tabsi-la should thus be situated somewhere in the same range to which the Kubi-gangri, Chema-yundung-pu and Ganglung-gangri belong. But from Tabsi-la one does not by any means come down directly to Map-chu, as could be expected. One comes down to the source region of Gyang-chu or Kyang-chu, the lower course of which I crossed near Camp 194.' Continuing southwards one has to cross a second range of mountains in a pass called Nangsa-la. The source of Gyang-chu is situated on the north side of this pass. To the south from Nangsa-la one comes to a region called Mogum, from the forests of which the sheets of thin bark we saw are said to be carried by the winds. This can hardly be anywhere else than in the Map-chu valley. The Gyang-chu should therefore partly be fed from the southern side of the Kubi-gangri and, further east pierce the range, the highest part of which is the same Kubigangri. But then one would expect to find the Gyang-chu as a very considerable river, which is not at all the case. However, very much depends upon the general configuration of the mountains. If the southern branch of the Tage-tsangpo, which Ryder has marked with a clotted line on his map, really has the course Ryder believes, then a good deal of the water from the southern or rather western side of the Kubi-gangri group goes to the Manasarovar. Another part may go to the Map-chu, and only a comparatively small remainder to the Gyang-chu. Probably only the S.E. part of the Kubi-gangri group drains to the Gyang-chu.

This part of N.W. Nepal, or the country S.W. of the Tibetan frontier is completely unknown and left as a blank on all maps. But from the information I got it really seems likely that there are two ranges between the Map-chu of Purang and the Kubi-tsangpo. S.E. of Gurla-mandata, Ryder has also two ranges, and this may be the case still further south-westwards. Therefore it should be possible to reach the southern side of Kubi-gangri by following the Gyang-chu upwards. This high region has many interesting problems and surprises in store for future exploration.

From Shamsang, Nain Sing's and Ryder's »furthest south>>, I had now, at Camp 200, proceeded 53.2 km. or 32 miles S.W., and the general hydrographical situation had become perfectly clear to me. I decided, however, to continue in the direction of the glaciers. So, on July i 2th, we marched another 16.1 km. or

I See p. 327.