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

spur which flanks the debouchure of the stream on the right bank. It ends where the cliffs on this
side too become impracticable. As I followed the little valley, cultivable all along its bottom,
upwards for about a mile I found it closed, where it narrows to about 200 yards across, by a battle-
mented wall which resembles in construction the main wall of the Chia-yü kuan 'barrier',⁴ and is in
any case of no great age; for the many loopholes piercing it, a true 'chiusa', were manifestly
intended for fire-arms. This wall, which was in good preservation except for the middle portion
exposed to damage from the stream, faced with its parapet to the south-west, i. e. up the valley. Its
purpose could not be doubtful. The precipitous rock walls, rising on either side to heights of 300
to 400 feet with unscalable faces, and the rugged nature of the hill range in general completely
protected this closing wall in the Hao-shan-k'ou gorge from being turned. Thus that portion, too,
of Huang-ts'ao-ying cultivation which lies outside the main wall was made safe from raids, and the
guarding of the latter itself greatly facilitated.

Second wall
facing in
inverse
direction. But a very puzzling fact faced me when, only some hundred yards higher up in the gorge, I found
the remains of another and distinctly older wall on either side of the low ground watered by the stream.
It, too, had undoubtedly been meant to close the passage through the valley; but strangely enough
its parapet, as seen in Fig. 253 on the left, faced to the north-east, i. e. down the valley. This
second wall, though massively constructed, had suffered far more decay than the first. It was built
of stamped clay with a thickness of 11 feet at its base, where it rested on a solid stone foundation
covered with a layer of rushes; its height, where greatest, was still 11 feet. The parapet, about
2 feet thick and 3 feet high, had no loopholes. Had the gorge been situated somewhere on the Indian
North-West Frontier, or on ground similarly affected by internal feuds in the past, it might have been
easy to account for two fortified positions facing each other at such close range. But here, on the
North-West Frontier of China, such an explanation would find no support in anything that we know
of its history. Hence the close proximity of such inverse lines of defence, and both by their very
nature manifestly of Chinese origin, was bound to appear from the first in the light of a problem.

Wall line
striking off
to north-
east. Before indicating what I now consider its likely solution, it will be advisable to complete the
account of my Chia-yü kuan survey with reference to another puzzling feature. I mean the line of
wall which on my first approach to Chia-yü kuan I had already noticed striking off at right angles
from the modern barrier wall and stretching far away to the north-east. It was at the very first of
the watch-towers guarding the wall north of the Gate, and only about a mile and a half from the
latter,⁵ that I found the junction of this distinct line. Its remains were far more decayed, as, in fact,
I had noticed from a distance, and closer inspection at once produced evidence of a different, and
probably earlier, date of construction. This wall, also built of stamped clay like the Chia-yü kuan
barrier, shows at its base a thickness of 8½–9 feet only as against the 11 feet of the latter. Its
height, exclusive of the parapet, is about 8 feet. Of the badly broken parapet only about a foot
remained here. The examination of the clay layers also disclosed a striking difference. Whereas
in the wall forming the Chia-yü kuan 'chiusa' they are 4 to 5 inches in thickness, those in the older
wall touching it here at right angles have a height of 10 to 11 inches.

Decay of
north-east
wall. The line of this wall, running south-west to north-east, is, as subsequent inspection showed,
broken by many great gaps. But though the aggregate length of these in the section here examined
is probably quite as great as that of the parts of the wall still standing, the alignment of the wall