know that the lake was salt. He knew that every lake without an outlet must be salt. If he had known the salinity of the lake he would never have accepted an outlet above or under ground from Gunchu to the Manasarovar. The premisses were quite different after Ryder and Rawling had visited the place and found that the water was salt and never drains into any other lake system. The thick ice covering the lake does not prove anything aganist the salinity, for Ngangtse-tso in the province of Naktsang is also salt and every winter covered with very thick ice. As all other salt lakes in Tibet the Gunchu-tso also diminishes in size. It cannot either be supposed that the Gunchu-tso in 1818 was really in communication with the Manasarovar and therefore fresh. For, as will be proved by this discussion, there is no indication of a great and decisive desiccation in the last i oo years. There is only a periodical fluctuation. But even in unusually wet years the Gunchu-tso has not drained to the Manasarovar, for if it had, the lake would not be salt. The period is too short to permit the lake to become salt during the depressions, and fresh during the wet years. I mentioned above the Chinese narrative which i 50 years ago gave the same description of the Gunchu-tso as Gerard and expressed the opinion that if, as the Chinese text puts it, the lake has a subterranean outlet, it could not be salt. Anyhow, the problem can hardly be definitely solved without a detailed examination of the ground, the beach-lines and the threshold which now forms a western boundary to the lake. My own opinion is that the Gunchu-tso, if really salt as Rawling says, cannot possibly have belonged to the Satlej system for a very considerable space of time.
The question whether the problematic river from Gunchu-tso or the Tagetsangpo should be regarded as the uppermost Satlej, has, however, nothing to do with the drainage of the Gunchu-tso. We have to deal with the problem as it is and not as it may possibly have been in prehistoric times. We have to use reliable observation and avoid uncertain information and hypotheses. In 1907 the Tagetsangpo was several times bigger than the Samo-tsangpo. If, in 1818, the precipitation was much richer than in 1907 the proportion should have been the same between the two rivers. Even if the drainage area of the Samo-tsangpo had been augmented by the area of Gunchu-tso, the addition in water from that lake can not have been considerable, — if it has ever taken place.
When Gerard thinks it is difficult to account for the rise and fall of the lake Manasarovar without supposing an outlet, he forgets that the rise and fall is much more considerable in self-contained basins than in lakes where the level is always regulated by the issuing stream.
For the Kailas he has heard the names Kylas, Kengree or Gangree; the Tibetans call it Heoonlas(?) or Kangree. He finds it strange that Moorcroft has so little to say about the mountain. But Captain Hearsay, in a sketch which Gerard saw, represented it as ending in a very acute point, and being far elevated above the other mountains.
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