52 MY FIRST JOURNEY IN NORTH-EASTERN TIBET.
(Jing-ri or Dschinri), which proceeds from the bluff of the same name. The delineation of this region by Carey and Dalgleish is clearer and more intelligible than Roborovskij's; indeed it is pretty plain, without having visited the locality, that the map of the latter is for this particular section artificially constructed. The material available is not however sufficient to give us a clear idea of the orography as a whole, to say nothing of it in detail. One thing however is evident, namely that between the valley of Kum-köl and the river of Tschulak-akkan there must be a water-divide of some kind, which possesses great morphological importance, for it must form the boundary between the basins of Kum-köl and Tsajdam. The swelling in question is possessed of the same significance as that which separates the river Tschumar or Namchutu-ulan-muren from the Tibetan highlands south of the Kokoschili range. And Carey and Dalgleish do indeed show it as a distinct swelling, situated south-east of what they call the »Sandy table-land», which corresponds to the drift-sand area I have alluded to above. They are consequently entitled to the merit of having given to the »Tschong-kum-kul» its proper position and dimensions. On Roborovskij's map not only the neighbourhood of the lake, but also the mountain-ranges that rise to the south of it, are altogether distorted, as I shall show more fully in the sequel.
At the beginning of the day's march we had on our left only one subsidiary offshoot from the mountains, and it soon died away westwards into low hills. On the other hand the Kalta-alaghan extended as far as we were able to see towards the N. 65° W., and in that same direction several snowy peaks appeared to lift themselves above its crest. The latitudinal valley slopes, as I have already said, towards the west ; its surface is soft and sometimes strewn with a sprinkling gravel from the Kalta-alaghan, and likewise produces grass, and hard woody teresken and similar scrubby plants. We passed only two or three small rivulets running down from the mountains, and they speedily disappeared in the dry soil. These originate no doubt in springs, for all the other watercourses, most of them very shallow, were dry. Only two or three were as deep as 3 to 4 m., and even their banks were not sharpcut or terraced, but rounded. Where we crossed over them they were running towards the west-south-west, but gradually inclined towards the west; and supposing them to be powerful enough, they ought to converge to form a main stream that empties into the eastern end of the Upper Kum-köl. But as a matter of fact they dwindle away before reaching the lowest part of the valley; consequently this possesses no main drainage artery, unlike the valley between the Tschimen-tagh and the Ara-tagh and that between the Ara-tagh and the Kalta-alaghan.
On the left, that is to the south, we had all day the drift-sand area, the highest pyramidal dunes of _ which are situated well towards the centre of the area. To what extent they are composed of pure drift-sand it was impossible to determine, for it is quite conceivable that the irregularities of the ground, hills and smaller heights, which may have been covered with sand, may make them appear bigger than they in reality are. It was equally difficult to make out with certainty in what direction the steep faces of the dunes looked; so far as I was able to judge from our route, most . of the dune-crests run from north to south and their steep faces are turned towards the east, so that the latest predominant wind that blew would
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