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

MEASURING THE TSANGPO AND THE CHAKTAK-TSANGPO.

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At the Chaktak junction the river had 9o.5cub.m. ; at the Dok-chu junction, 305 km. lower down, only 75cub.m. ; though many tributaries are received on the way.The difference of course depends on the fact that the river was measured at the latter place 53 days before the measurement at the Chaktak junction; it should also be remembered that all the northern tributaries from the Transhimalaya are caught by Raga-tsangpo. From the result we get an absolute proof that the Tsangpo constantly rises from day to day during April and May, a rise which, of course, continues the whole summer till the absolute maximum is reached.

A small oscillation of the water level of the Tsangpo could be observed. In the morning of May 29th it stood 25mm. lower than at 3 P. M. the day before; at 3 P. M. on 29th it had again risen, and stood i 5mm. higher than 24 hours before. This must chiefly depend upon the local weather, and the different speed of melting day and night in the nearest tributaries.

From Camp i 68 our road follows the northern bank of Chaktak-tsangpo N.W. and W.N.W-wards below or on the top of its 5m. high terrace. The valley is level to the eye and the current very slow, having no rapids at all. Once or twice the river is divided into two or three arms. The valley is broad and open, about I km., and surrounded by rather low mountains, a series of shoulders, generally with some living rock visible, green schist, either at the base or as ridges on the crest. The Chaktak-tsangpo is here enclosed between two ridges with short transverse valleys, a few of them with brooks.

From the left, or north, we observe the following tributaries : Ählung-rong, Chang-lung, Muga with a brook forming a little delta at the junction, and coming from a considerable mountain group in the background; Pelung-ongma, Pelungkongma, and Nimdong. Tögden is a promontory just below Camp i 69. From the right or south enter the tributaries : Kha, Tingring, Kera-lung, and Gulung. There are some good pasture-grounds in the valley and bushes grow at a few places; at Nimdong were two tents and flocks of sheep and goats. There is not much gravel, but a good deal of sand, either forming rudimentary dunes, or terraces with steep

sides, and grass on the top. Kyangs are common. Mani-riçmos, chor/ens and ruins are often seen along this road which seems to have been very much frequented; the

walls and towers on some hills are probably remains of fortifications from times of hostility with Nepel.

A half storm was blowing from the west the whole day, and the air filled with dust.

From Camp 169, at 4,5 2 5m. ( I 4,842 feet), we again leave the Chaktaktsangpo, and ride up the Takbur valley to the N.N.W., and then turn N.N.E. rising considerably. This valley is rich both in grass, bushes, water, and wild animals, such as kyangs, foxes, lynxes, hares, arctomys, rabbits, partridges, pheasants and small birds. Great flocks of tame yaks are seen. Near the pass a few snow-patches may still be seen in shady places.

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