Sec. ii] THE CULTURE-STRATA OF YOTKAN 195
the excavations touch the gardens and fields of Allâma (see Fig. 2 7), it shows an average of from 5 to 8 feet. In the banks on the west it seems to increase gradually as they approach the vicinity of the Yôtkan-Yâr (see Fig. 26). North of the latter the ` culture-stratum ' attains its greatest thickness, being fully 13 to 14 feet deep in the banks worked immediately below the houses of Khalche, where the proceeds in antiques, such as terra-cotta figurines, coins. small fragments of carved stone, &c., are the richest. It was chiefly here and along the northwestern edge of the area that recent working was proceeding. The banks to the south and east, where the relatively thin culture-stratum had ceased to be ` paying ', showed signs of having been abandoned for a considerable number of years, as proved by the fruit-trees planted just below them within the excavated area.
It was easy to see that, notwithstanding the uniformity in the character of the culture-stratum, there were variations in the relative frequency of the objects embedded in it. In some places the pottery fragments were closely packed, forming small layers or patches easily distinguishable on the surface of the banks, whereas elsewhere only isolated pieces could be picked out. In the same way bones, ashes, &c., are far more plentiful at certain points than at others. It is clear that the varying depth of the culture-stratum must be ascribed mainly to the different length of the periods during which particular localities were occupied, and to the different character of the uses to which they had been put. Of the latter fact the variations just noted afford direct evidence.
In one respect all portions of the culture-strata exposed to view show a regrettable uniformity ; nowhere did I come upon traces of structural remains, nor could I hear of such having been found during previous excavations. The nearest approach to such remains was represented by a layer of closely packed large pebbles, which the banks on both sides of the YôtkanYâr, just where it enters the excavated area from the west, showed in a thickness of about 52 feet and about toe feet above the present bottom of the ravine. The stones must have been brought from some river-bed, but whether they served for a platform, foundation of a wall, or some similar purpose could not be determined. Above this layer I noticed the occurrence of ancient pottery fragments, while none were exposed below it 9.
I believe that this absence of structural remains is to be accounted for by the fact that, owing to the total want of suitable stone, sun-dried bricks and clay supplemented by timber must have been in old days, as now, the only materials available for the construction of houses in the Khotan region. All of the mud walls of buildings that had not crumbled into dust was bound to decay completely in the course of the centuries during which. as we shall presently have occasion to demonstrate, the site was taken up for cultivation and the soil kept constantly moist by the percolation of irrigation water. The same fate overtook, of course, whatever of the wood once contained in the more substantial buildings had not been extracted and utilized by successive occupiers of the site. It might have been different if the old town, of which the ` culture-strata ' of Yôtkan now retain the sole relics, had been overwhelmed by some sudden catastrophe and its site once for all deserted. Then we might expect to find the original materials and even some structural outlines of buildings preserved in a recognizable form under the soil. The assumption of such a catastrophe, a great flood which was supposed to have destroyed the old town, has indeed been hazarded by some of the earlier European visitors to Yôtkan, who attributed to it the thick cover of earth now