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

Change of
climatic
conditions
near T'u-to-
fan.

A striking change, however, came over the ground on ascending towards the T'u-ta-fan from
the gravel plateau beyond the Po-yang Ho.⁶ The broad valley leading up to this pass, the western-
most of those which cross the Richthofen Range proper, proved to be clothed with luxuriant grass
and flowers that recalled true Alpine vegetation. It was the first, but sharply marked, indication
of the distinct change in climatic conditions which was subsequently observed right through the
Nan-shan ranges south-eastwards and, in a lesser degree, also in the submontane tracts adjoining
them on the north. We were here leaving behind the extreme south-eastern limits of the great
arid belt of innermost Asia, as represented by the Tarim Basin and the adjoining drainageless areas,
and were entering that westernmost portion of true China which, remote as it is, is affected in its
climate by the increased moisture passing up from the Pacific.

Physical
divisions
meet near
Chia-yü
kuan.

It is important that we should realize clearly the meeting at this point of two great physical
divisions of Asia; for this geographical fact has had its manifest bearing upon the position of what
has been the recognized main western entrance into China for the last five hundred years, if not
longer. I mean the famous Gate of Chia-yü kuan, the modern representative of the ancient Jade
Gate. Its distance from the debouchure of the T'u-ta-fan valley is less than twenty-five miles, and
the contrast between this verdant alpine vale and the arid wastes of the Nan-shan beyond it to the
west is scarcely more striking than the change experienced by the traveller as, having crossed a vast
stony steppe from the west, he reaches the 'Great Wall' and, through the Gate of Chia-yü kuan,
passes into the succession of fertile tracts within. My own approach to this western end of the
'Great Wall' was singularly adapted to bring out the big features of its topographical setting. So
I may well briefly describe it before discussing Chia-yü kuan itself.

First sight
of 'Great
Wall'.

I had my first sight of the Great Wall, and a very impressive one, when after descending from
the T'u-ta-fan I rode on the evening of July 18 along the fantastically eroded foot-hills of the Nan-
shan eastwards to the hamlet of Ta-han-chuang.⁷ To the north an utterly lifeless steppe of stone
and gravel, fully twelve to fifteen miles wide, was seen to separate this fringe of the snowy Nan-shan
from a terribly bare hill range running parallel to it and forming a south-eastern offshoot of the Pei-
shan. As I looked down from a height of close on 8,000 feet, the view ranged unbroken along this
vast valley or plateau eastwards. Far away in the distance low gravel ridges, marking the water-
shed towards the Pei-ta Ho, seemed to form an eastern rim of the plateau. Along this the setting
sun lit up a long-stretched faint streak of white—the line of the 'Great Wall'. The distance
separating me from its nearest point was still close upon twenty miles. But in the clear atmosphere
it was possible to make out towers reflecting the slanting rays and, stretching away to the horizon
beyond, a great expanse of dark ground. It was the fertile district of Su-chou with its green fields
and arbours. Set off clearly against the grey of the steppe and the red of the bare desert hills, it
made me realize with my eyes what China 'within the Wall' (kuan li-t'ou) meant, and why its
border was drawn here.

Approach
to Gate of
Chia-yü
kuan.

The little fortified post of Ta-han-chuang (Fig. 251), which I visited next morning, was tenanted
by a few soldiers as an outpost of Chia-yü kuan to watch the route along the foot of the mountains.
Its massive watch-tower and the small walled enclosure adjoining, both half-ruined, seemed an apt
illustration of what posts on the ancient Han Limes might have looked like, though in a far more
desolate setting. The same day a long weary march brought us transversely over the bare stony
'Sai' of the valley to a point on the high road about four miles west of Chia-yü kuan. All view of the
wall and its great Gate had vanished in the glare of the day. Instead there loomed before us the
eastern extremity of the long barren range already referred to as overlooking the valley from the
north. A glance at its steep serrated ridges, furrowed by a maze of narrow ravines, sufficed to