Chap. IV) NOTES ON SHEETS No. 20 79
tion with my visit of 1907 to the ruined site of Khiira (D. 4). The plane-table work has been adjusted to the positions adopted for Kara-shahr, Korla and Bugur; see Notes on Sheets 21, 24.
For an account of my visit to Khôra, cf. Desert Cathay, ii. p. 372; Serindia, iii. pp. 1224 sqq. The northern slope of the' outer Tien-shan range then seen, appeared very barren, and even in the wide valley of the Khaidu-gol, stony but scrub-covered in
parts, there was little to suggest the rich grazing which has macle the plateaus of Yulduz at its head favourite haunts for nomad tribes from the times of the Huns down to the Mongols of the present day. But on ascending to the Kara-dawan (A.4) by a route which leads from Yangi-hissar to Yulduz, Lal Singh noticed fine pine-forest clothing the southern slopes of the range from an elevation of about 8000 feet upwards.
NOTES ON SHEET No. 21 (BUGUR, KORLA)
The area shown in this sheet forms part of the extreme north-eastern corner of the Tarim basin proper. Of the routes along which the surveys lay, those leading from Korla to the Inehike-darya were followed in 1908 and the rest, mainly north and south of them, in 1915.
The compilation of this sheet and those immediately adjoining to the east and southeast has been adversely affected by the erroneous longitude adopted at the time for the position of Korla in connection with R. B. Lal Singh's northern triangulation series along the Kuruk-tagh. In paras. 2-4 of Major Mason's Memorandum prefixed to Appendix A, the circumstances have been explained which necessitated in 1921 a re-examination of the computations relating to this triangulation and led to the rejection of its distant connection with the southern series of the same surveyor's triangulation along the K`un-lun range.
The western extremity of the northern series, as marked by station CC 85 (3170) in Sheet 25. A. 1, approaches Korla within about 5 miles, and as a result of the revised computation it was decided to base the work of the northern series on Mr. Clementi's value of Korla (lat. 41° 44' 20.8", long. 86° 10' 10.4"). While the tables of Appendix A now show throughout the revised values for R. B. Lal Singh's triangulation stations and
13 With reference to Major Mason's statement in para. 4 of his above quoted Memorandum about the difficulties attending compilation owing to war conditions, I may conveniently here mention that my absence in England during 1916-17 prevented my being consulted at the time as to the doubts thrown upon the computation results of the northern series In relation to the position of Karla.
In Sheet No. 49 of the IS06-08 Map the approxi.
points, it has been impossible to rectify their positions as shown in the map sheets. The corresponding correction in the case of Korla necessitates a shifting of its longitude by about 15' 30" to the east, while the latitude remains practically unchanged .13
In addition to the latitude observations recorded below, use was macle also for the main road of those available from Mr. Clementi's work and for the Tarim river route (Ugen-darya) from that of Dr. Hedin. The latter route and that along the Inchikedarya were adjusted in longitude to the values derived for Peres and Shahyar (Sheet No. 17) from the traverse between Kueha and the Keriya river.
For a brief account of my observations regarding the Korla oasis and the ancient topography of this region, see Serindia, iii. pp. 1230 sqq. There the reasons for the surveys made in the desert between the Konche-darya and Inehike-darya have also been explained. The part played by the riverine tracts of the Inchike-darya and Tarim in early historical topography is discussed in Serindia, iii. pp. 1236 sq.
Except for the presence of some drift-sand belts towards the Konche-darya, the area shown in this sheet south of the line of oases along the foot of the Tien-shan, shares the character of the scrub- and jungle-covered zone extending around'the cultivated
mately correct longitude of 86° 10' is shown for Korla. That the erroneous longitude now adopted for liorla has not seriously affected the compilation of the work further west may be concluded from the notes above (Sheet No. 17) concerning the longitude of Kuehl', and also from the fact that the longitude 84° 10' 20r shown for llugur-bâzar in our sheet, (A. 1) accords well with the chronometrical value of Dr. Vaillant, viz 84° 11', 1 (see La Géographie, 1921, p. 498).