sources. After leaving behind the watershed of the Keriya River at an elevation of close on 18,000 feet, we turned westwards for the exploration of the ground which figured generally in atlases as a high plain with the name of ' Ak-sai-chin ', but which the latest trans-frontier map of the Survey of India rightly showed as a blank. Instead of a plain we found there high snow-covered spurs crowned by peaks up to more than 23,00o feet, and between them broad barren valleys, descending from the great range which overlooks the Yurung-kash headwaters from the south (Maps Nos. 22, 29, 33). At the debouchure of these valleys there extends a series of large isolated basins, all at an elevation between 15,000 and 16,000 feet, holding lakes mostly dry. It was fortunate that easy saddles leading over completely decomposed cross spurs facilitated progress over this dismal ground ; for owing to its utter barrenness, which after the first lake (Map No. 29. D. 4) was passed left no longer even a pretence of grazing, our ponies and donkeys, in spite of all care, succumbed here in rapid succession.
After a week of long marches from where we had left the track to the Lanak-la a large salt lake was reached which had been sighted from afar more than forty years before by a triangulation party of the Survey of India, but which had now dried up for the most part (Map No. 22. D. 4). Its approximate position was shown in the sketch-map intended to illustrate the route followed by Mr. W. J. Johnson on his adventurous journey from Ladâk to Khotan in 1865. This prepared me to look out for that old route, and after three more marches to the north-west across absolutely sterile basins, holding salt-encrusted dry lagoons and without animal or plant life of any sort, we struck its traces to my great relief (Map No. 22. B. 3). Two small stone-heaps, half-buried under coarse sand and gravel, found at the mouth of a valley leading northward, were the first trace left by human hands since we had crossed the Baba-Haim Pass to the Keriya River sources a fortnight earlier.
The survival almost intact of these rough little cairns, of stacks of dead ' Burtse ' roots found higher up the valley, and of some other small relics left behind by those who followed this route during the few years (1864-6) it was open, was characteristic of the dryness of the climate even at this great elevation. To find them in perfect preservation seemed striking proof how little of human presence the desolate high plateaus just traversed of the extreme north-west of Tibet could have seen ever since history began.
The track still perfectly well defined in most places, though not trodden by man for over forty years, led to the pass which in Johnson's sketch-map was shown as ' Khitai-dawân', and by the evening of September 18 we emerged at last in the valley of the eastern feeder of the Kara-kâsh. There a shelter roughly built with unhewn stones marked the ' Hâji-langar' (Map No. 22. B. I) of which Satip-aldi Beg, the old headman of the Kirghiz in the upper Kara-kâsh Valley, had told me as having been built by Hâji Habib-ullah's order, when this ill-fated rebel ruler of Khotan (1863-6) opened his own route across the high Ktun-lun Range south of Karanghu-tagh to Ladak. Two days later I was joined lower down in the Kara-kâsh Valley by a party of Satip-aldi Beg's Kirghiz with the supplies and transport arranged for from Khotan. So the difficult expedition through the Kun-lun ranges seemed now successfully ended.
But there still remained one exploratory task, all the more tempting to me because it offered also a quasi-historical interest. It was to trace Haji Habib-ullah's route up to the point where it
crossed the main K'un-lun Range above Karanghu-tagh by a high glacier pass, and thus to determine the exact position of the ' Yangi-dawân ' of Johnson which our surveys of 1900 and 1906, carried out from the opposite side, had failed to reveal." For this purpose I marched back with the Kirghiz and their yaks to below Haji-langar, where a line of cairns that obviously continued the one found