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 EASTERN AND SOUTHERN SHORES OF RAKAS-TAL.   167

of harzburgit in 24°N.4o°E., but amongst the detritus one finds granites, gneiss, crystalline schist and other specimens generally rounded by the waves. At the western side of the promontory the harzburgit dips 76°E., and still farther west 47°E. A narrow valley opens to the bay west of the promontory and here is a road from Purang; a caravan of sheep, just passing here, came from Purang and was on its way to Lumaring-tso and Kerki in the interior of Western Tibet. The valley was called So-longyo, though this name is doubtful.

Then follow some small bays and promontories and finally a large, not very

deep bay, before Camp 227 is reached at the very point of a sharp, rocky peninsula. The rock is the same harzburgit as before, now in 4 I °N.2°E. N.N.E. and not far from the shore is a little rocky island, Lache-to. It takes only 25 minutes to walk round the island along its shore. It consists of solid rock rising steeply from comparatively deep water, or 34.5m., halfway between the island and Camp 227. The rock of the island consists of the same harzburgit in 38°N.4o°E. At the foot of the rock are heaps of detritus and sometimes more or less well developed terraces. The north-eastern part of the island forms an open plateau, and here, amongst sand, gravel and vegetation, the wild geese breed in spring and early summer as could be seen from thousands of eggs. The people of Parka plunder the nests of the wild geese every spring, and reach the island on the ice, which indicates that at least this more protected part of the lake remains frozen rather long, say six months. A little ring all also proves that the island is occasionally visited.

The section of the shore from Camp 227 to 228 is also very irregular, for

the mountains of the southern shore send forth a series of ramifications and spurs forming promontories and peninsulas. In each bay between them a valley or ravine is formed, sometimes with terraces, seldom with a minimal brook, which disappears into the gravel before it reaches the ashore. These little valleys seem to be very short, and there is hardly room for any considerable length, as the great Purang valley is near at hand on the southern side of the ridge.

Following this shore one has a feeling of being in a labyrinth between water

and land. The perspective is very picturesque and changes every moment. One has a series of promontories westwards and understands that each of them is situated between two bays. A terrace follows the foot of the rocks ; it is exactly I om. high (August 3oth), and at Camp 227 it was 48m. from the shore; sometimes it is interrupted or disturbed. The same harzburgit rocks continue the whole way, in 73°N.45°E., 48°N., and 4o°N.7o°E. The two islands are easily visible in the south-western corner of the lake, but one can only seldom make out that they are real islands and not parts of promontories. There may possibly be three of them. The greatest is called Dopserma, though other Tibetans called it Dotser.

One promontory- could be cut off in a pass about worn. above the lake. \Vest of it is a long narrow bay. At the sides of a valley coming out here, per-