It is difficult to guess how much truth there is in the ancient traditions that the water-courses of the empire were improved through gigantic engineering works undertaken by the ancient Emperors of China. There is one gorge, well known to travellers, above Ich'ang, on the River Yang-tsz, on the way to Ch'ung-k'ing, where the precipitous rocks on each side have the appearance and hardness of iron, and for a mile or more--perhaps several miles-- stand perpendicularly like walls on both sides of the rapid Yang- tsz River: the most curious feature about them is that from below the water-level, right up to the top, or as far as the eye can reach, the stone looks as though it had been chipped away with powerful cheese-scoops: it seems almost impossible that any operation of nature can have fashioned rocks in this way; on the other hand, what tools of sufficient hardness, driven by what great force, could hollow out a passage of such length, at such a depth, and such a height? It is certain that after Ts'in conquered the hitherto almost unknown kingdoms of Pa and Shuh (Eastern and Western Sz Ch'wan) a Chinese engineer named Li Ping worked wonders in the canalization of the so-called CH'ÊNg-tu plain, or the rich level region lying around the capital city of Sz Ch'wan province, which was so long as Shuh endured also the metropolis of Shuh. The consular officers of his Britannic Majesty have made a special study of these sluices, which are still in full working order, and they seem almost unchanged in principle from the period (280 B.C.) when Li Ping lived. The Chinese still regard this branch of the Great River as the source; or at least they did so until the Jesuit surveys of two centuries ago proved otherwise; it was quite natural that they should do so in ancient times, for the true upper course, and also Yiin Nan and Tibet through which that course runs, were totally unknown to them, and unheard of by name; even now the so-called Lolo country of Sz Ch'wan and Yiin Nan is mostly unexplored, and the mountain Lolos are quite independent of China. The fact that they have whitish skins and a written script of their own (manifestly inspired by the form of Chinese characters) makes them a specially interesting people. Li Ping's engineering feats also included the region around Ya-thou and Kia- ting, as marked on the modern maps.