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196
THE INDIAN ANTIQUARY
(SEPTEMBER, 1917
tamarisk fascines, and of the usual thickness of 8 to 9 feet, still rose to close on 15 feet. Special difficulties must have been encountered in assuring water and supplies for the men guarding this section. In order to safeguard what evidently was an important line of communication and supplies leading to it, a chain of small fortified stations had been cor.structed to the south independently of the wall, but at the same period. It ran in the direction of the big oasis of Su-chou, an important Chinese base ever since Han times, and to this I turned when early in May it became necessary to make preparations for our next move northward.
I had planned to follow the united course of the rivers of Su-chou and Kan-chou down into southernmost Mongolia, and to explore the ruins which the reports of Russian travellers had led me to expect along it and in its terminal delta. I was specially attracted to this ground by its geographical character, which suggested close resemblance to that of the Lopnor region, and by the interest attaching to its earliest historical past. For we know that this region of the Etsin-gol, as the river is called by the Mongols, had been included in the wide dominion held by those earliest nomadic masters of Kansu, the "Creat Yüeh-chih," the later Indo-Scythians, and the Huns, whose successive migrations westwards were destined to affect so cleeply the history of Central Asia as well as of India and the West.
The effective intercession of H.M.'s Minister at Peking had secured for me a very friendly reception by the Chinese administration of the Kansu Province. The Tao-tai of Su-chou agreed to provide me with a recommendation to the chief of the Torgut Mongols who now graze in the Etsin-gol delta, and on May 10 I was able to set out northward. The track) followed down the river of Su-chou allowed me to approach once more the area where we had previously lost the line of the ancient frontier amidst high dunes. Pushing a reconnaissance into the stony desert north-west of the Chinta oasis, I came upon remains of the Limes where it emerged on less impracticable ground near the south-eastern extremity of the Pei-shan. Thence we tracked it right through to the north of the Mao-mei oasis, the last Chinese settlement. There Lal Singh rejoined me after having followed a hitherto unsurveyed route along the river of Kan-chou, where it breaks in a picturesque gorge through the westernmost hill range of the Ala-shan.
In the valley of the Etsin-gol, nature, by affording water and grazing, has ever provided an easy route for raids and invasions from the Mongolian steppes into the line of the westernmost Kansu oases, which itself constitutes the great natural highway connecting China with the Tarim Basin and innermost Central Asia. Ruined forts of imposing size and evident antiquity were found to guard the point where this route of invasion cuts through the ancient border-line drawn by the Chinese, when they first occupied those oases in the reign of the great Han Emperor Wu-ti. One fort built with clay walls of exceptional strength looked an exact counterpart of the ancient frontier post of the " Jade Gate," famous in Chinese historical records, and previously identified by me on the Tun-huang Limes. We found evidence that the fortified border-line after crossing the Etsin-gol, north of Mao-mei, had continued through the desert eastwards. But when we came back in June from the Etsin delta the summer heat had become too great to permit of further search on this waterless
ground.
We found even in May our long marches trying as we moved down by the sandy bed of the Etsin-gol, nearly a mile wide in places, but absolutely dry at that time. Only at rare intervals could water be obtained from wells dug in deep hollows below the banks. Some 90 miles below Mao-mei the river passes through a low rocky spur thrown out from