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

THE UPPER RAGA-TSANGPU.   297

My road then follows the Raga-tsangpo for two days. The valley rises slowly to the W.S.W. At first it is rather narrow, but soon becomes half a kilometre broad,

and halfway it opens out to a breadth of 3 to 5 km, and is more like a plain.

The ground is hard and even, partly covered with gravel, partly with low close grass, which sometimes forms a real steppe. As a rule, the river keeps to the right

or southern side of the valley; it is open the whole way; only in the more protected and shadowy side valleys is there still ice. At Camp 16o, the Raga-tsangpo carried 51!2 cub. m a second; the current is quick, but seldom forms rapids in this part of its course.

On the left or northern side of the valley the mountains are higher than on the right. They are wild, steep, rugged and rocky, pierced by short, narrow valleys, and here and there covered with patches of snow, but between the valley and them there is a confusion of low, yellow, rounded hills, for some 1 o km. The southern mountains are, as far as can be seen from our road, of respectable, but no great height, and nowhere covered with snow. The river sweeps along their foot and does not leave room for any marked erosion terrace, as on the left or northern bank. In the openings of the side valleys, however, one sees some more noticeable massives, one of which is called Marpo, another Rinak, or, according to other informants, Ngangbakanja. Through the Ngangba valley one sees to or 12 km south a short ridge, stretching east and west.

From east to west we notice several tributary valleys; from the north: Kyakchung, Töchung, Racho, Tökya; beyond a small isolated rock is Tibuk; the rock is here grey sandstone, forming small thresholds hardly rising above the ground; to the west a hill gives a beautiful view over the whole valley with the great mountain group of Chomo-uchong in the background; Shalung is a small valley with 15 m high erosion terraces; Pendem is larger; both these join the Teeng-chu before entering the Ragatsangpo; Salung is a small valley issuing from between low hills; Parva is the next, quite full of ice in its mouth; finally Yalung and Lungchung. From the right side, i. e., from the southern mountain range which is situated between Ragatsangpo and Tsangpo, we have Tipkuk; Shärlung and Sukshin, which join before leaving the mountains; Damlung, Naga and Ngangba, the latter comparatively large, whereas the Tograng is short and steep. Of course, none of these valleys can come from any far distance, as there is no space between the two great rivers. But even the northern tributaries are very short and, as far as can be seen, none of them has been able to pierce the range which I take to be the western prolongation of the Nien-chen-tang-la. The Dongmo-chu from Amchok-tso is the single one which pierces the range. We have seen that the Mü-chu-tsangpo also pierces it further east. But whether there is any other tributary, between Dongmo and Müchu which breaks through the range cannot be ascertained from what we know at present. A party from Ryder's and Rawling's expedition followed the Raga-tsangpo

38-141741 III.