Chap. IV] NOTES ON SHEET No. 7 69
further south towards Marat-bâshi in that and thence through the previously unexplored
of 1915. On both occasions the atmosphe barren outer ranges of Kelpin to the desert
ric conditions of the season seriously inter south, is given in Desert Cathay, ii. pp. 423
fered with astronomical observations as well sqq. • The general physical conditions of the
as with distant views towards the mountains. region from Ak-su to Kelpin and Maral-
This, together with the damage suffered by bashi have been summarily discussed, along
R.B. Lal Singh's theodolite on the former with its historical topography, in Serindia,
journey, explains why only a single latitude iii. pp. 1296 sqq. .
observation of our own (that for Kelpin, The large if imperfectly cultivated areas
B.3) falls within this sheet. of Ak-su and Ueh-Turfân owe their occupa-
Fortunately Mr. C. Clementi's astrono tion to the abundant irrigation supplied by
mical work of 1907 along the Kashgar-Ak the Taushkan' and Kum-arik rivers which
su highroad met this want by supplying unite close to the ' Yangi-shahr ' or Chinese
latitudes and chronometric values of longi town of Ak-su. Both are fed by portions
tude for Ak-su (Yangi-shahr) and for several of the Tien-shan carrying perpetual snow
of the roadside stations between that place and in their higher (unsurveyed) valleys
and Maral-bâshi. 8 The longitude thus affording ample grazing. The outer ranges
determined for Ak-su, 79,° 55' 25", shifts the to the south of the Taushkan river are on
position accepted in the Russian Trans- the other hand extremely arid, and the few
frontier map and shown also in Dr. Hassen- small settlements at their foot wholly depen-
stein's map accompanying Dr. Hedin's dent on subsoil drainage.
Reisen in Zentral-Asien, 1900, by some 29 South of those ranges extends a wide
minutes to the west, while the difference in desert plain, partly bare clay or gravel but
the same sense from the longitude deduced mainly covered with sand from alluvial de-
from our plane-table traverses of 1908, as posits; in this plain, percolation from the Yar-
shown in Sheet No. 23 of the Serindia map, kand and Kashgar rivers aided by occasional
is only about 8 minutes. 4 The difference in inundation maintains abundant jungle vege-
latitude of the position in the latter from tation. The winding Kara-köl bed, together
that of Mr. Clementi (41° 7' 57") is less with other branches (C, D. 4) filled at times
than 6 minutes to the south. The routes of flood, carries the water of the dying Kash-
passing through Uch-Turfiin and Kelpin were gar-darya occasionally as far as the southern
checked by the accepted positions of Ak-su, end of Ak-su cultivation. The curious wind-
Kashgar and Maral-bashi, use being made eroded low hill-chains (A, B. 4) striking
also of the latitudes observed at Kelpin and across this desert plain at right angles to the
Tunguzluk (Sheet No. 4. C. 4). Tien-shan axis have been referred to already
A descriptive account of the route sur above ; see p. 26.
veyed by me from Ak-su to Uch-Turfân Astronomically observed latitude.
1913-15. Kelpin, Camp 342 (Belt's house, E. of Bazar; B. 3) ... 40° 31' 23"
NOTES ON. SHEET No. 8 (MARA.L-BASHI)