SECTION II.—PAST THE MAO-MEI OASIS AND ITS OUTPOSTS
The advance of the season and the increasing heat, from which our camels had already begun to suffer, made it important to push on down the Etsin-gol. It was therefore doubly gratifying
that, thanks to the help of Mr. Chou 1-lua-nan 14, the youthful Hsien-kuan of Mao-mei or
Mao-mu,1 we were able, during a single day's halt on May 14th, to hire the additional camels required to lighten the loads of our own animals ; to secure some useful preliminary information about the route which I was anxious to follow from here through an unexplored portion of the Pei-shan on our return journey of the autumn, and also to obtain, as a guide along the Etsin-gol, an intelligent and willing young Chinese, accustomed to act as traders' agent among the Mongols of that ground. On the same day Lai Singh rejoined me, having carried out his survey of the Kan-chou river from the point where it breaks in a tortuous course through the barren hill range that edges the great plateau on the north. He had, moreover, by following this route, been able to ascertain that the cultivated area of Mao-mei, narrow but over thirty-five miles in total length, extends much farther southward along the river than appeared from the cartographical sources previously available (Map No. 42. D. 4). But throughout this long stretch of cultivation and in the forlorn looking little town with its decayed Ya-mêns and few shops, there was evidence of the serious damage which a succession of deficient summer floods during the preceding two or three seasons had caused to all local interests. Supplies were quite unobtainable. The small garrison ordinarily maintained here had been recently withdrawn, it was said, for the same reason.
Even before the discovery of the Han Limes leading towards Mao-mei along the Pei-to-ho, there were strong geographical reasons for the belief that this outlying oasis, scanty as its resources might be, must have been of considerable importance for the protection of the north-western marches of Kan-su. Nature, by affording water and grazing over a continuous line of some two hundred miles, has at all times provided in the valley of the Etsin-gol an exceptionally easy route for raids and invasions from the Altai region, that true home of the Mongols and other great nomadic races, towards the line of the westernmost oases of Kan-su. These, extending along the foot of the Nan-shan, constitute the great natural highway between China and innermost Asia. Wide belts of desert and barren hill-ranges stretch both to the west and east of the Etsin-gol. These belts, very difficult for any large bodies of men to cross, hardy nomads though they may be, help to protect this important ` corridor ' for trade and military operations against serious attack from the north. But the valley of the Etsin-gol stands open, like a gate inviting invasion. We shall see that through this gate came the first great onslaught of the Mongols, under Chingiz Khan's leadership, which led to China's conquest and absorption in the greatest empire Asia has ever known. On how many previous occasions Huns, Turks and other nomadic races from the northern steppes had used this gate for the invasion of north-western China, is a subject well deserving study by those who have access to Chinese historical sources.
It will suffice here to point out that those who since the first Chinese advance under the Emperor Wu-ti into ` Ho-hsi ' were concerned with the safeguarding of this indispensable passage land between China and Central Asia, were not likely to ignore or neglect the advantage that a cultivated area, well to the north of the great highway and yet easily capable of support from the side of both Su-chou and Kan-chou, would necessarily present for the purpose of a barrier whereby to close