reason the Tibetans drive them over this dangerous piece of road one by one; but even then some of them prefer, as the photograph shows, to pick their way amongst the broken rocks above the actual track. This issues finally upon the gravelly scree at the mouth of an eroded watercourse, and then descends abruptly to the lake-shore on the other side of the rocky promontory.
At the new camp the profile of the shore was as shown in the accompanying illustration (fig. 201); b indicates the highest of the strand-terraces visible from that side; it forms a projecting ledge built of pebbles from the gravel-and-shingle and sand, cemented together into a compact mass as hard as stone. The upper edge of the ledge is I I.5 m. above the existing level of the water, and is thus younger than the beach-line which I measured and described before. That this gravel-andshingle ledge can be nothing except an old beach-line is clear from its horizontal position, and the reason it projects in the way shown in the illustration is that it has been undermined by the action of the waves and of the ice, of which action we had already observed several instances at the existing lake-level. On the adjacent hard rock no such traces are visible, the cause being, I have no doubt, the relatively rapid decay of the schists. On the same illustration a indicates the characteristic strand-rampart formed by ice-pressure, being so steep on its outer side that it was as much as ever we could do to climb over it. At this particular spot it was 3.o6 m. above the lake, though in other places it is a little higher. Its height above the interior narrow strip of shore (c) was 57 cm. On its outer side too it possessed a very narrow strip of level ground close to the edge of the ice, consisting as usual of sand, mud, and ooze, and the differences in the thickness of its layers shows that it is the result of ice-pressure applied over several years. In places there is a thin dark layer of rotting Alg, with mollusc-shells intermingled with them. On Plate 49 a section of this rampart may be seen.
In the neighbourhood of Camp CXLIII the lake on the morning of December 4th was frozen in the manner shown in the accompanying sketch (Pl. 50). Here again the open reaches were found principally along the southern shore, their cause being as before the presence of springs; for were there none, that part of the lake which lies during the major portion of the day under the shadow of the lofty mountains on the southern shore would become frozen sooner than those parts which lie exposed to the sun on the north. The ice in the bay near our camp was at 6 p. m. 9.7 cm. thick, and at the thinnest place just off the promontory it had a thickness of 5.2
Hedin, Tourney in Central Asia. IV. 38
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