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

1100

ranges of the Nan-shan.² Together with its outlying hamlets, Ch'iao-tzŭ probably counts fully
two hundred households, and the picturesque walled enclosure within which the main village
shelters, together with numerous temples and other substantial structures now half in ruins, proves
that the oasis must have been a far more populous settlement before the havoc wrought during
the Tungan rebellion. It owes its existence solely to the abundance of fine springs which come
to the surface in the extensive marshes to the south and south-west of the main oasis.

Grazing
grounds in
Ch'iao-tzŭ
valley.

Besides assuring plentiful irrigation to the area cultivable by the present population, the water-
supply from these and other springs accounts for the luxuriant grazing to be found over an area
which can safely be estimated at not less than 150 square miles. The valley must have been an
attractive winter grazing ground for any non-Chinese race once established in this region, nomadic
or semi-nomadic, such as the Yüeh-chih or Hsiung-nu, before the Chinese advance to the western-
most Kan-su marches drove them northward. Tibetans, Uigurs, and Tanguts must also have
appreciated its advantages, in conjunction with the grazing to be found in the higher valleys to
the south, while their hold over these parts lasted. But Chinese deep-rooted aversion to the
herdsman's life and calling leaves this rich grazing wholly unused now, and the traditional dread
of nomadic neighbours, kept alive by sad experience down to Tungan and Tangut raids, jealously
prevents access to it by those who could use it. There are similar winter grazing areas to be found
also in places along the foot of the Nan-shan further east towards Kan-chou and beyond, and this
geographical fact deserves to be emphasized here; for the historical student must keep note of it
if he wishes to account for the successive domination of westernmost Kan-su by races which were
essentially nomadic. Their prolonged occupation would have been physically impossible if the
whole of this region had been either such utterly barren desert as the wastes west of Tun-huang
and north of the Su-lo Ho, or else capable of supporting human existence only where irrigated and
tilled by a laborious settled population, as is the case practically everywhere within the plains of the
Târim Basin.

Physical
features of
So-yang-
ch'êng site.

The physical features of the ground on which I found the reported 'old town' to be situated
also presented distinct interest. The site proved to be a large one, and very instructive in several
respects. Its remains are scattered over an area extending, as the map shows (No. 83. n. 3, 4), for
about five miles from east to west and for over three miles from north to south at its eastern end.
Proceeding due south of the walled village of Ch'iao-tzŭ, one crosses cultivation for about a mile, and
then for nearly three miles more a belt of luxuriant vegetation fed by marshy springs. Beyond the
southern edge of this, and screened by a narrow zone of tamarisk-cones, there stretches the ruined
area, partly undergoing wind-erosion and partly overrun by low dunes which tamarisk growth and
reeds are binding in places. After crossing for another mile ground which closely recalled to me
that of familiar 'Tatis' in the Khotan region, I reached the conspicuous remains of a walled town
forming an irregular quadrangle, with outer enclosures that are far more decayed adjoining on the
north and west, as shown by the site plan (Pl. 46). Its position is marked β on the map. The
name given for it by the Ch'iao-tzŭ villagers was So-yang-ch'êng.

Wind-
eroded
ground near
ruined site.

Outside the town to the east and north-east, for a distance of 3–4 miles, scattered remains of
clay-built towers and walled enclosures, together with patches of thick pottery débris from dwellings
completely eroded, mark the extent of the once closely occupied area. The cultivated ground of
the old oasis is likely to have spread much further. The whole of it occupies a flat stretch of fertile
loess soil extending along the edge of the bare gravel glacis which slopes down from the hill range
on the south. The latter is a continuation of the one which I subsequently passed on the way from
T'a-shih to Wang-fo-hsia. This loess belt, wherever left unprotected by vegetation owing to want