It seems probable, from the work of Professor J. W. Gregory and others, that the Kin-sha — that portion of the upper Yangtze with which this book deals — formerly continued on its southward course and reached the Gulf of Tong-king.
(1) At about the same time their number was 573,981 in the eastern half of Sikang Province, including nineteen districts east of the Kin-sha River; (2) and 321,945 in the western half.
In the eighth century, a Chinese suspension span over the Kin-sha River hung from iron chains, and similar bridges were built in Yunnan and in the mountains of Tibet.
