conceive I ought to touch again upon the main points of the controversy which have invested this problem with such a fascinating interest, and I feel under all the greater obligation to do this because Kosloff, in the book that he has recently published, has devoted a very great deal of attention to this question, claiming to have settled it in a sense favourable to Prschevalskij. Strictly speaking, this controversy, which has now continued for 25 years, may almost be disregarded, seeing that all the arguments, geological as well as historical, no matter whether they tell for the one party or for the other, are alike superfluous; for the facts, both the geological facts and the historical facts, speak their own plain and irrefutable language. But it is just because we possess these facts that it will be interesting to glance back over the different phases of the discussion, for the facts themselves are well calculated to bring out the real value attaching to the several arguments.
An account of Prschevalskij's second journey in 1876-77 will be found in Delmar Morgan's translation;* and the same work contains the controversy which arose between von Richthofen and Prschevalskij. Here I will cite a couple of passages from the paper** by von Richthofen, using Morgan's translation. Knowing, as we now do, that von Richthofen was right, it is especially interesting to recall the arguments upon which he relied. His proof is remarkable for its acute discernment, and his paper deserves to be regarded as a classic document in the history of the exploration of Central Asia. I may add, that it was this paper which led to my making both my journeys to the Lop-nor region. Richthofen says:
»It is remarkable, that Prejevalsky found the last reservoir of the Tarim much farther south than the maps and Chinese information placed it, and that the water was fresh instead of salt. — — — The statement about the second basin (Karakoschun), which answers to the true Lob-nor, and must be the last evaporating reservoir of the Tarim, is most surprising. The region through which the Tarim flows is highly charged with salt, springs of sweet water are rare, and only appear on the borders of the mountains. — — — The water of the Tarim must therefore contain a larger proportion of salt than any other of the larger rivers of the world; and the unusual amount of evaporation, continued through a great many centuries, must have produced a very large deposit of steppe salts of all kinds. The Chinese from ancient times have called Lob-nor the salt lake, in contradistinction to the many other salt lakes of smaller size. Contrary to theoretical deductions and historical records, we now learn from the first European explorer who has visited the lake, that its water is sweet. Let us endeavour to suggest some explanations.
In winter, when the evaporation is only slight, the river coursing rapidly down to the lake might be expected to diffuse sweet water over the strongly condensed alkali. But, on the other hand, the insignificant depth of the lake would scarcely allow of a dispersion of the salt. A second explanation can be found in the supposition, that the reservoir of the waters of the Tarim has undergone changes
* From Kulja, across the Tian-shan to Lob-nor, London, i 879 ; and see also Peterm. Mitteil., Ergänzhft No. 53, Przewalsky's Reise an den Lob-nor und Allyn-tag, 1876-77.
** Bemerkungen zu den Ergebnissen von Oberstlieutnant von Prjewalski's Reise nach dem Lop-nor und Altyn-tagh, in Verhandl.. der Gesellschaft f. Erdkunde (1878), v. pp. 121 fl., and Petern:. Mitteil. (1878), XXIV. pp. 313 ff.
IIIF Color HighRes
