changes could have taken place in the course of sixteen centuries, and evidently is persuaded that the hydrographical conditions remained unchanged from the 5th cent. to about 1817. And yet we know that in 1308 the Dragon Town was destroyed by an inundation, evidently a shifting of the lake. He has no idea that the only mouth which existed in 1817 was altogether different from the one mouth spoken of by the Han-scliu. This last was the mouth of the Tarim's Kuruk-darja, emptying into the old, northern Lop-nor; the former is the mouth formed about 1740, the present embouchure of the Tarim into the Kara-koschun. As, according to Himly's surmise, the Chinese author did not himself visit the Lop-nor, he confuses the Karakoschun with the Lop-nor of the old writers; but it is a mistake for which he may readily be pardoned, seeing that the same mistake has also been made by Prschevalskij and Kosloff, notwithstanding that they both visited the region several times.
In the same breath in which the Chinese author appeals to the Han-scliu to prove, that there is only one mouth, he also mentions the small lakes, of which three, round in shape, lie north of the big lake of Lop-nor, and four, elongated ones, lie south of the same. It would thus appear that this statement also rests upon the authority of the Han-schu of the 5th century. Ali I-Kung does not mention these seven small lakes, but on the other hand he does mention a very small lake on the southern shore of which an ocean of sand extends, while south of that there are plenteous steppe and kamisch-fields on the northern shore of Lop-nor (i. e. Kara-koschun or Utschu-köl). One proof that the circumstances in 1759 were different from what they are now is to be seen in the fact, that there are no such thick belts of vegetation on the northern shore of the Kara-koschun. Nevertheless, as I shall attempt to prove lower down, it seems as though the position assigned to Lop-nor on the map belongs to a far earlier time than that of the small lakes.
These seven small lakes are all marked on the Wu-tschang map, on the map in the Si yü-schuei-tao-ki, and on a third map, the I-thung-yü-thu map, mentioned by Himly. As I have already pointed out, Lop-nor is placed on the first-named I I/i too far to the west, consequently the seven lakes too share in the displacement. The latitude is 40°30' to 40°45'. If the four lakes to the south of the Lop-nor really did occupy the positions relatively to the big lake which is assigned to them on the map, the one farthest south, Ör-kou-hai-thu, ought to lie about 4o km. from its _ southern shore. From this it follows that the Lop-nor of the Wu-tschang map cannot be identical with the Kara-koschun, for at the distance of only 17 km. south of the shore of the last-named, that is to say at Dungluk, the altitude is already more than 200 m. above the level of the Kara-koschun itself, and at 4o km. distance it is double the altitude of the Kara-koschun. Accordingly the Lop-nor of the Chinese map lies at all events north of the Kara-koschun, and as its latitude agrees with • the latitude of the depression which I discovered immediately south of Lôu-lan, it is consequently this last which is represented on the map in question.
Turning now to the seven small lakes, I observe that the three northern ones, which bear the common name of Thsao-hu, or the Grass Lake, are probably identical with the extreme northern parts of the Lop-nor, the region immediately south of the Kuruk-tagh where I discovered the survivals of the old kamisch-fields. They were no doubt directly connected with the Lop-nor, into which the Kuruk-
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