188 THE OSCILLATIONS IN THE WATER-LEVEL OF THE LAKES.
This was during a summer with very little rain. On July. 2 5th, 1907, the Samo-tsangpo had only 0,73 cub.m. On July 23rd, 1908, the same river had 4.89 cub.m., or nearly 7 times as much water, which came down, however, after a very heavy rain. The channel from the two lagoons, receiving Patchen, Pachung and Lugnak, carried on August loth, 1907, 1.76cub.m. and on July 25th, 1908 at exactly the same place, 4.orcub.m., without being immediately influenced by rain. It is therefore no exaggeration to say that in 1908 three or four times as much water reached the Manasarovar, as in 1907. In the following years the amount was still increasing as we have seen.
The list given above shows that the Tage-tsangpo, with j
j.26cub.m., is incomparably larger than any one of the rest. The next largest is the Namreldi from Gurla-mandata with 2.86cub.m. Then comes the Pachung-chu with 2.36 cub.m. Samo-tsangpo comes as No.' o in the list, only two brooks being smaller. Some attempts have been made to award the honour of being the source of the Satlej, to the Samo-tsangpo, or, at any rate, that this river with the same right as the Tagetsangpo could be regarded as such. But it is not sufficient to look up the map and decree that one river or the other should be accepted as the source of the Satlej. Only actual measurements can decide the question. Now the Tage-tsangpo carries, even at its mouth in the lake, 5 times as much water as the Namreldi at the foot of the mountains, and 15 times as much as the Samo-tsangpo. So there can be no doubt which of the affluents to the Manasarovar must be regarded as the source of the Satlej, — from a hydrographical point of view.
It could perhaps be objected that this holds good only for the year in which the measurements were carried out and that the distribution of water may be otherwise in rainy years. But then we only need to remember that the Tage-tsangpo, in a very dry year, was 2 or 3 times larger than the Samo-tsangpo in a rainy year, and just after a heavy rain. And comparisons should of course be made under similar conditions prevailing all over the drainage area. Proportionately the volumes of the 12 water-courses will always and under all conditions be the same as I found them in 1907.
Finally it should be remembered that the historical points of view exactly agree with the hydrographical results.
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