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Digital Archive of Toyo Bunko Rare Books

height 2,391 for the western edge of that
basin, are derived from this levelling oper-
ation. The height of Bêsh-toghrak (2,340),
obtained as the mean of several observations,
was accepted as datum point. ²⁰ᵃ The record
of levels, as shown in Appendix C, proves a
continuously descending slope from the an-
cient lacustrine basin to the dried-up Lop
sea bed.

A descriptive account of the ground
along the caravan track, as seen on my first
passage, is given in Desert Cathay, i. pp. 525
sqq.; ii. pp. 1 sqq., and a summary of its
characteristic features in Serindia, ii. pp.
549 sqq.; cf. also Geogr. Journal, 1916, xlviii.
pp. 129 sq. The topography of the ground
south of the Su-lo-ho, along the ancient
Chinese border line or Limes (C,D.4), and of
that on its western flank which the terminal
marsh basin of the Su-lo-ho served to protect
(C.4), has been touched upon passim in the
account given of my fruitful archæological
explorations on this Limes portion, in Desert
Cathay, ii. pp. 92-158. The physical cha-
racter and historical topography of the
ground along the several sections of the
Limes has been discussed in the detailed
record of those explorations, in Serindia, ii.
Chapters XVII-XIX; see in particular pp. 633
sqq., 656 sq., 662 sqq., 693 sqq., 705 sqq.
There frequent reference has been also made
to the evidence furnished by the ancient
remains and records regarding the physical
conditions, water levels, etc., prevailing here
during the first centuries before and after
Christ.

Though limited in extent and fairly
uniform in character, the surveyed area of
this sheet possesses special geographical
interest. It comprises the wide trough of
the terminal course of the Su-lo-ho, separat-
ing the southernmost Kuruk-tâgh from the
gravel glacis of the easternmost Altin-tâgh.

Astronomically observed latitudes.
1906-08. Bêsh-toghrak, Camp 152 (at well; B. 4) ... 40° 29′ 41″
Toghrak-bulak, Camp 154 (on left bank of river bed; C. 4) ... 40° 19′ 35″

To the north of the marshy depression (B,C.
4) in which the present bed of the river ends,
we have other branches, now dry, of an
ancient delta descending into an earlier termi-
nal basin; the lacustrine character of this
is clearly marked by its strings of Mesas. ²¹

Immediately to the west of this basin,
the 'Su-lo-ho trough' is continued in the
previously mentioned valley leading down
from Bêsh-toghrak to the eastern bay of the
dried-up Lop sea bed. There is evidence
supporting the belief that through this nor-
thern basin the Su-lo-ho drainage reached
the ancient Lop sea until a recent geologi-
cal period. ²² It is probable also that perco-
lation from it, even within historical times,
helped to facilitate the use of the Bêsh-
toghrak valley for the early Chinese route
towards Lou-lan. It certainly accounts for
the desert vegetation to be found today in
this valley, notwithstanding the utter bar-
renness of the Kuruk-tâgh on one side of it,
and of the high ridges of drift-sand on the
other.

Along the Su-lo-ho course and the line
of spring-fed marshes which accompany it,
such vegetation is abundant. But the con-
figuration of the ground precludes irrigation,
and the evidence of the plentiful documents
recovered from the ruined watch-stations of
the Limes makes it certain that already in
ancient times no cultivation existed along
this desolate border-line.

Corrections. A. 4. R. B. Lâl Singh's
Camps 50 and 51 of 1913 should be shown
circ. 6 miles S.W. of Kosh-kuduk and circ.
7 miles S.W. of Yantak-kuduk, respectively.
Against Camp 50 of 1913 should be added
the height 2,500.

C. 4. The height of Toghrak-bulak
should be corrected into 2,837 (see Appendix
B).