on account of the condensation of the monsoon clouds. The valleys on the S. W. side are also, as we have seen, cut very deep. The erosive activity has been much greater in them than in those on the N. E. side. Or in other words, the relative differences of altitude are much greater on the S. W. than on the N. E. side. The small transverse valleys which go down at the N. E. side have a very gradual fall towards the centre of a self-contained basin on the high plateau-land. The amount of water flowing down through them is not great. The relative difference of altitude between the crest of the Kara-korum Range and the general surface of the plateau-land, is very small, as may be seen from the first marches to the N. E. from Chang-lung yogma. Seen from the plateau-land the water-parting Kara-korum Range may rather be called a slightly elevated edge of the plateau-land itself, and by no means as a considerable mountain range forming its boundary to the S. W. On the S. W. slopes of the range, on the other hand, even the small valleys develop a respectable amount of erosive energy. Their gradients are much steeper, they receive the greater part of the precipitation, and they cut down their furrows to a greater depth. Therefore, the water-parting range of the Kara-korum appears from the S. W., as we saw in the Slang-lung- valley, as a considerable and bulky mountain range, though without any high, snow-covered peaks which could at all be compared with the giants situated on the second, or highest Kara-korum Range, which is to be found on the S. W. side of the water-parting line.
What I have discussed here are general rules derived from the observations made during my crossing over the Chang-lung yogma Pass. The same observations could be made during my second crossing, over the Daj5sang, nearly 1 'J~ year later. To a certain extent they may again be made on the Kara-korum Pass, though there the morphology is somewhat different. This is nearly all that can be said with any degree of certainty. And how very little is it not when compared with the enormous extent of the water-parting Kara-korum Range ! Honestly we may say that we know only perhaps a dozen points on the water-parting line itself! We, therefore, have only a very slight and vague idea of its situation, and if we try to make a map of it, most will have to be drawn by interpolation and consist of mere guesswork. If so little hitherto has been conquered, it is easy to understand that there is work enough to be done in the future. Hundreds of thousands of small valleys take their rise from the range. A minimal number of them is known. And there are many great valleys which have not yet been visited and, much
less, mapped.
From my standpoint above the pass, lines of mud-flow could again be seen in the soft, wet material on the slopes. Only about one fifth of the area of the ground near the pass was still snow-covered. The panoramic view from the pass itself was far less dominating than the one I had sketched.
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