CHAPTER XL.
CONTOUR-LINES OF THE UPPER TARIM BASIN.
I have devoted two whole volumes of this work to a description of the Tarim and its tributaries, its lakes and surrounding deserts, but I have given no attention to the absolute altitudes, nor yet to the relative, though they are in many respects of great interest. The reason of this is that it seemed to me more desirable to discuss the hypsometrical data in connected form. In this and the succeeding chapter I will touch upon certain matters which arise out of them; and in Chapter XLII I will yield place to Dr. Nils Ekholm, who, in an interesting and important essay, has kindly given a general account of the manner in which he has dealt with my hypsometrical observations and of the different methods which he has employed in working them out.
Plate 58 is a map of the Tarim depression, designed to give a picture of the general shape of its basin. A single glance at it suffices to convince us of the great flatness and regular structure of the basin; it is only in the north-west that the contour-lines exhibit any irregularity, and there appears another slight departure from uniform regularity between the Chotan-darja and the Kerija-darja. Towards the bases of the mountains, that is to say the Tien-schan in the north, the Pamir in the west, and the Kwen-lun in the south, the curves become more crowded together, and if we attempted to trace them out up the relatively steep detritus scree, they would resolve themselves into a single continuous black 'mass on the map. How much more then would this result ensue did we attempt to follow them up in the mountains! But as a matter of fact it will be a long time before contours can be drawn for these mountains, which as yet are so imperfectly known. On the whole, our elliptical or oval basin bears in a high degree a resemblance to a spoon, the hollow of the bowl being at Kaschgar, and from there the fall slopes more and more gradually down to the tip of the spoon in the Lop country. The resemblance may even be carried one step farther, for just as a liquid contained in a spoon is poured out over its tip-end, so in like manner is the water that is contained in the Tarim spoon emptied out over its farther end in the country of Lop.
IIIFカラー高解像度
