304 THE LOP-NOR PROBLEM.
the west; and the Ilek, with its lake-like expansions, and the belt of salt lagoons and marshes which accompany its eastern bank, are really but paltry remnants, not again of the Lop-nor, but of the curving of the migratory river.»
»These facts and these explanations disprove the arguments which Sven Hedin has adduced in support of his hypothesis of the existance of a former and second Lop-nor.»
»The only conclusion I am able to draw from the whole of the foregoing investigation of the Lop-nor problem is, that the Kara-koschun is not only the Lop-nor of my revered teacher N. M. Prschevalskij, but also the ancient historical and true Lop-nor of the Chinese geographers.»
In these words Kosloff defines the standpoint he assumed after my first journey to the Lop-nor country. How little tenable it was is clear from my later explorations. One idea which I entertained in i 896 I have seen cause in some respects to change since my fresh visit to that region. I was earlier of opinion that the chain of lakes, Avullu-köl, Kara-köl, Tajek-köl, and Arka-köl, were surviving remnants of the ancient Lop-nor, transformed in shape and altered as to position. That idea is however only in part correct, in so far as these lakes do lie in the same depression as the old Lop-nor, and so far forth may be regarded as newly arisen descendants of that lake. But on the other hand it is doubtful whether the position of the lake has been altered by winds and sand in the way I formerly represented. It is indeed quite true, that these two natural powers are at this moment encroaching upon the eastern shores of these lakes, the dunes penetrating into the water and so advancing westwards across the lake, while the vegetation gets left behind, so that in their present stadium their eastern shores may be said to be travelling west, but it is not credible that this process has been going on since the time of the old Lop-nor, and is still incredible even when we suppose that there have been arid intervals in between. At the present moment I am unable to decide the question, though, now that the basin of the old Lop-nor has actually been discovered, it is a question of no importance. How far to the east these four lakes extended at the maximum can only be determined by fresh journeys in the Desert of Lop; and even then it would be difficult to arrive at a final solution, because the sand, under which the entire region lies buried, is pretty high and difficult immediately east of the lakes. In any case Kosloff has no right to attempt to reduce the dimensions of these lakes. Although he has never seen them himself, he nevertheless takes it upon him to declare, that they really are nothing more than expansions of the Ilek. Is it not indeed just to such riverine expansions as these that we generally do apply the term lakes ? And as for the lakes in question, we have found that they contain depths nearly twice as great as even the maximum depth of the Kara-koschun. Moreover a comparison between the mean depth of the Kara-koschun and the mean depth of this eastern chain of lakes yields very interesting results. The mean depth in the current which traverses the northern part of the first-mentioned lake is, we found, 2.7 m., and that of the southern i.o m., the mean of all the soundings being 2.366 m. Taking into account the approximate dimensions of the lake and the volume it receives, we calculated that its real mean depth is 0.8x m. In the several lakes of the eastern waterway the mean depths are as follows:
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