SURVEYING THE DESERT. 249
But other factors are certainly concerned in the relation which exists between the results of wind-erosion and the consistency of the soil, and after only two hurried visits to the region it is difficult to form a clear conception of them. I am indeed the only European who has visited the Lop-nor. I could of course have made inquiries amongst the natives and ascertained whether the winds which were blowing in the spring of 1896, 1900, and 1901, were indeed the prevailing winds, the winds typical of the country; but on the other hand, it would have been quite impossible to ascertain how far one and the same storm possessed the same power, and blew in the same direction, in all parts of the desert alike. The quarters to which the wind-eroded gullies point would seem to indicate that the wind does not possess the uniform direction suggested; but the same storm would appear to produce different effects in different parts of the desert. Lacking as we do the requisite observations, our conclusions must in several respects remain mere guesses. And in any case it must be next to impossible to obtain full certainty with regard to the wind relations in the interior of Asia. Hitherto we have heard nothing about meteorological stations in waterless deserts. The point to which I desire to call especial attention is, that the relative difference of elevation of one or two meters which my survey brought to
light may quite well be attributed to wind-erosion.
A discovery which we made in the vicinity of the above-mentioned round pit-like depressions would appear to indicate, that the level has not been lowered by wind-erosion since the lake dried up. This was a stake of tamarisk wood 35 cm. longs half buried in the ground, and undoubtedly placed there at a time when the locality was under water. The lower end of the stake was sharply pointed and burnt. Three of my attendants, who were Lopliks, thought that it had been used to moor canoes to, when their owners had been out on an exploring expedition, and had been unable to reach dry land before
nightfall. At the present day the Lopliks in similar circumstances are accustomed to fasten two or more canoes together in some shallow place, where in case of a storm arising they will not be in too great danger, and so pass the night in them. But it is equally possible that a shore may have run through that spot, and that the stake was situated at its edge. At all events, the condition of the ground showed distinctly that it was moist when the stake was put in; for were such a post to be driven forcibly into the hard schor, the latter would crack and split. But the post was as fast as if it had been cast in the schor, and it required two or three smart side-blows to loosen it. This piece of wood furnished another proof, that this part of the desert was once a lake-bottom, and that the lake was navigated by boats. It would be erroneous to suppose that it was a tent-stake, because the Lopliks when away from home with their canoes sleep under the bare sky.
If now the wind-erosion, or rather corrasion, had been powerful, the stake would not have been buried 18 cm. in the ground, but would have been lying free upon the surface. As to the question, what lake this was, and how far it was connected with the northern or the southern depression — these are matters to which I
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