Sec. iv.] THIRD EXPEDITION, 1913-15 35
series of expeditions for the exploration of unknown or as yet inadequately surveyed portions of the Kuruk-tagh and Lop deserts to the south.
At the same time it became possible also to utilize my prolonged stay for a detailed large-scale survey of the chief parts of the Turfan basin. Geographi-
Geoeraphical interest cal and antiquarian interests united in calling for such a survey ; for of Turfin basin.
apart from containing in its terminal salt lake probably one of the deepest land depressions below sea-level of our globe, it exhibits, within close topographical limits and hence in a particularly characteristic form, all those physical features which make the Tarim basin, its great neighbour and counterpart, so instructive both to the geographer and the historical student. For the latter a close survey of the territory must offer additional archœological interest on account of the very numerous ancient remains which have survived within or near its oases, and which strikingly attest its importance and resources in the past when Turfan served as a chief link between Buddhist Central Asia and the Far East.
This work, on the one-inch scale and with clinometrically observed contours, was entrusted to Muhammad Yaknb and carried on by him under such control
Detailed surveys in as his periodic visits to my archœological camps permitted me to-
exercise. In the end his plane-table sheets, seven in number, covered the whole of the central part of the Turfan depression and comprised all its oases ancient or modern with the exception of Toksun in the extreme west of the basin. 60 With this and the other surveys of my two expeditions it is hoped to prepare a detailed map of the Turfan district, on the scale of 1:250, 000, for publication in the Royal Geographical Society's Jour. nal, together with a short monograph on the geography and historical topography of the territory. Iu addition, I may mention, both Afraz-gul and Muhammad Yakûb were engaged during our work at Turfan in preparing Iarge-scale plans of important ancient sites, such as the ruined towns of Kara-khôja and Yttr-khoto, etc., to be published in my Detailed Report on the third expedition.
By November 12th I was able to let R. B. Lai Singh start from Kara-khbja for fresh
hard work in the Kuruk-tagh to the south. His instructions were to reach Singer, the only small inhabited place in those truly 'Dry Mountains', by a new route from the south-east corner of the Turfan basin 61
and thence to start triangulation towards Altmish-bulak in the south-east with a view to securing, if possible, a connection across the Lop desert with the easternmost points on the K'un-lun range fixed during the preceding autumn. Owing to the incipient season of dust storms no chance for sighting those distant peaks had offered during our stay at Âltmish-bulak in February, 1914. But experience during my first explorations at the Lou-lan ruins in December, 1906, had shown the possibility of such rays being observed under particularly favourable conditions. At the same time the rapidly increasing cold gave hope that after Lal Singh's arrival at Singer and the establishment of a triangulation base there, the season would be sufficiently advanced to permit of the difficulties arising from the want of drinkable water further east being overcome by the use of ice formed on salt springs.
Lâl Singh carried out this programme with his accustomed persevering energy in the
face of great hardships and privations, helped once again by that experienced hunter Abdurrahim and his hardy camels. By the middle of December he had carried a system of triangles from his measured
base near Singer to Âltmish-bulak. 62 There a fresh base was measured, but the chance of sighting the K`un-lun range south was vainly awaited for a week, the usual desert haze and the distance, over 130 miles, effectively preventing a view. Lai Singh then moved one march hither south to the salt spring of Àstin-bulak and after again waiting under still more trying conditions of extreme cold and exposure succeeded at last on December 23rd in sighting a portion of the distant range. Observations were made from both ends of a new base to a peak
Plan for Lil Singh's
surveys in Buruk-tigh.
Singer to Altmish-bulak.
60 The one-inch scale survey extended from the Pichan oasis in 'the east (Sheet No. 31. A. 3) to the vicinity of Altan-mazir in the 'west (No. 28. B. 3 ), and fiàm about lat.43° South to the terminal salt lake Vidforming the deepest -portion ' Of ' the Turfin
61 For the route followed from Deghar to Arpish. me-bolak, two marches N. of Singer, see Sheet No. 28.. B.'4. C. 4. D. 3.
62 See Sheet No. 29. B, C. 2, D. 3.