16 FROM CENTRAL TIBET TO LADAK.
the river with horses and camels would have been in the vicinity of Camp LXXII. Very often the stream was divided into two or more branches by flat islands of silt or sand. From the point where the river assumes a south-westerly course, it alters its appearance in that it increases still more' in breadth: while the eroded banks still preserve a height of 4 to 5 m., the distance between them increases. Here they are equally high on both sides of the stream, the river flowing as it were at the bottom of a deep trench with vertically cut sides. The depth is inconsiderable, and the skiff frequently grounded even where the current ran strongest. Here then the depth would offer no impediment to the passage of a caravan; but the bottom did not bear everywhere and the scarped banks presented an insuperable obstacle. About one-half of the river-bed was occupied by alluvia, across which the water gently wound its way. During high flood these patches are beyond doubt completely covered with water, so that the lowest part of the course of the Satschu-tsangpo must then form a single wide current, flowing between perpendicular escarpments and moving everywhere with considerable swiftness.
About 5 km. north-west of the river rises a small ridge in the glen-opening, and on its slopes we saw herds of yaks and sheep, besides one or two tents. Except for this the country adjacent to the river consisted to all appearance of a perfectly level alluvial region, of hard, dry, horizontally bedded yellow clay, clearly a former lacustrine deposit, through which the Satschu-tsangpo now ploughs its way. From the point where we embarked down to its mouth the river is joined by no tributaries, though there are indeed dry gullies formed by transient rains and making, as it were, narrow gateways or sharp incisions in the high scarped banks. Every now and again we passed a tiny eminence beside the river; but these were the only
Fig. 9. TIBETAN TRYING TO CATCH A LIVELY HORSE.
IIIFカラー高解像度
