National Institute of Informatics - Digital Silk Road Project
Digital Archive of Toyo Bunko Rare Books

of Kan-chou were surveyed on the second
expedition.

The compilation of the sheet is prima-
rily based on the positions adopted for Su-
chou (see Notes on Sheet No. 43) and Kan-
chou. The latitude of the latter city was
determined by closely concordant astronomi-
cal observations taken on the two journeys
(38° 55′ 41″ and 38° 55′ 36″, respectively).
But the plotting of the several traverses
carried on the third expedition between
Kan-chou and points lower down on the
Kan-chou river (No. 43. D. 1, 2) has led to
a change in the longitude value assigned to
Kan-chou. It is shown now as 100° 38′ 20″
against 100° 49′ 30″ in the map of the sec-
ond journey (see Sheet No. 94. D. 1 in
Serindia, vol. v).

This new value approximates very close-
ly to the longitude of Kan-chou as indicated
in Sheet No. XXI of the Russian Asiatic
Transfrontier map (circ. 100° 37′ 30″), but
differs notably both from Mr. Clementi's
chronometric longitude, 100° 21′ 29·16″,
and that adopted by the Survey of India in
previous publications, approximately 100° 49′
30″. These discrepancies as to the position
of an important and well-known city strik-
ingly illustrate the need of exact longitude
observations by telegraphic or wireless me-
thods along this great highroad from China
into Central Asia.

The area shown in this sheet corresponds
in all essential physical features to the three
regions distinguished in Sheet No. 43, of
which this is the continuation. In the south
we have the eastern portion of the Central
Nan-shan, as far as it is drained by the
headwaters of the Kan-chou river and by its
upper tributaries. The broad valley of the
O-po-ho, the river's eastern main feeder
(B. 4, 5, C. 5), is a pendant to the wide up-
lands met near the sources of the river's
main western branch (No. 43. B, C. 3).
But the snow-line appears to lie some-
what higher on the eastern continuation of
the enclosing ranges. The difficult gorges
in which the Kan-chou river, below the junc-
tion of both branches, has cut its way
through the Richthofen Range, are impas-
sable except in the depth of winter and still

await their explorer.

The plateau stretching along the nor-
thern foot of this range gradually widens
south-eastwards as the spurs descending from
the latter recede. The large cultivated
area around Kan-chou (A, B. 3) is accounted
for by the fact that the abundant waters of
the Kan-chou river can be utilized here to
full advantage for irrigation over a wide
alluvial fan. The same holds good also with
regard to the oases around Sha-ho-p'u (A. 2),
irrigated by the Li-yüan-ho.

To the east of the longitude of Kan-
chou cultivation along the foot of the Richt-
hofen Range becomes independent of
irrigation, owing to the increased precipita-
tion which approach to the Pacific drainage
assures. This important change of climatic
conditions is duly reflected also in the exten-
sive patches of conifer forest which the map
shows here right down to the foot-hills
(A. 3, B, C. 4). Further away from the
Nan-shan, however, this influence of a moist-
er climate appears to diminish rapidly, and
north of latitude 38° 45′ no cultivation seems
possible without irrigation.

The hill range which on the north
separates the inhabited plateau from south-
ernmost Mongolia rises in the vicinity of
Kan-chou to heights well over 10,000 feet;
yet its slopes are uniformly barren through-
out. The route surveyed from Mao-mei to
the Kan-chou river near Kao-t'ai (A. 1, 2)
afforded striking evidence of the great aridity
of the climate prevailing in the belt of low
hills and wide desert valleys which stretches
north of the middle course of the Kan-chou
river.

The route through the mountains, fol-
lowed in 1907 from the Kan-chou river
headwaters to the city of Kan-chou, is de-
scribed in Desert Cathay, ii. pp. 328 sqq. For
observations on the historical topography of
the Kan-chou tract and of the old Chinese
highroad passing through it, see Serindia,
iii. pp. 1131 sqq. Brief preliminary notes
on the routes followed by me in 1914 from
the Etsin-gol basin to Kan-chou, and thence
to the eastern headwaters of the river, are
recorded in Geographical Journal, xlviii. pp.
199 sq.

Astronomically observed latitudes.
1906 08. Sha-ho-p'u, Camp 227 (above left river-bank, outside eastern gate;
A. 2) ... ... ... 39° 9′ 24″