国立情報学研究所 - ディジタル・シルクロード・プロジェクト
『東洋文庫所蔵』貴重書デジタルアーカイブ

63

CHAPTER IV

NOTES ON INDIVIDUAL MAP SHEETS

NOTES ON SHEET No. 1 (TURUG-ART-DAWAN)

The survey of the small area comprised in the S. E. corner of this sheet was made by R. B. Lâl Singh in 1907. Owing to the damage his theodolite had suffered on the way from Ak-su, no latitude observations of his were available for this area. His route from Kâshgar to the Turug-art-dawân (Sheet No. 1. C. 3) on the Russian frontier lying almost due north, it was considered advisable to accept for the position of the latter the coordinates obtained from the latest Russian surveys and to adjust the details shown in this sheet on that point and on the accepted position of Kish gar (see below Notes on Sheet No. 2). The position of the Turug

art pass on the surveyor's- plane-table, as indicated by Sheet No. 1 of the 1906-08 Map, lies about 4 minutes of lat. to the south and circ. 9. minutes of long. to the west of that shown by the Russian map.

The fact that the Turug-art-dawan is reached from Kâshgar by a road which shortly before 1907 had been made practicable for country carts at the instance of the Russian authorities, sufficiently indicates the comparatively easy character of the ground over which this route along the Chakmak valley leads up to the Tien-shan watershed.

NOTES ON SHEET No. 2 (KASHGAR, MUG TAGH-ATA)

The area shown by this sheet comprises a considerable portion of the great meridional range connecting the westernmost K'un-lun with the T'ien-shan in the north and forming the eastern rim of the Pamir region. In it appears also the extreme north-western corner of the Tarim basin proper, occupied by the large oasis of Kish-gar and the much smaller ones of Opal and Tâsh-malik.

The routes surveyed on the first journey led along the western slopes of the merididnal range, usually known after its most prominent peak as that of Muz-tàgh-atà, as far as the great defile of Gez-dara (C.3) and then through this to Tâsh-malik and Kâshgar. The surveys of 1906-08 falling within this sheet were confined to the ground in its south-eastern and north-eastern corners. Those of 1913-15 were of greater extent and were carried not only through the main valleys receiving the drainage from the eastern flanks of the Muz-tagh-ata massif, but also along both sides of the northern portion of the range, where it approaches the T'ienshan and gives rise to the main feeders of the Kâshgar river.

For the delineation of the Muz-tagh-ata range, between the approximate latitudes of 38° and 39°, and of the great valleys

which flank its western slopes, a considerable number of triangulated points were available. These were derived mainly from the triangulation work of 1900, analyzed in sections B, C of Major Mason's Appendix A. In addition, certain points on the main range fixed by the operations of the Pâmir Boundary Commission and Captain Deasy could also be utilized. The extension of R. S. Rim Singh's triangulation to Tâsh-malik (D.2) permitted the course of the Gez-dara, or valley of the Yaman-yâr river, to be accurately shown on the map right down to where it debouches into the great plain of the Tarim basin.

Besides the triangulation results just referred to, the position accepted for the 'old town' of Kâshgar and those for Yirkand and certain other places in the adjoining sheets Nos. 1, 3, 5 were used for the adjustment of the plane-table surveys embodied in this sheet. The value assigned to Kishgar, lat. 39° 28' 45", long. 75° 58', is that hitherto adopted by the Survey of India from the mean of numerous observations by successive expeditions. It deserves, however, to be noted that the longitude value which wireless observation on Sir F. De Filippi's expedition furnished for a point close to Chini-bagh, the British Consulate