Drainage of the Yaiig-tse Bad.. ^257 



covered to the depth of several feet ; a vast inland sea is 

 formefljxi the centre of China, a few tree-tops, and roofs of 

 houses still standing, alone breaking the boundless water 

 horizon. When we see that each summer nearly half an 

 inch of sediment is deposited, and the level of the surround- 

 ing country raised each year to that extent, we cannot help 

 being struck with the fact that there must have been a vast 

 lake bottom to fill, — seeing that the soil set free by the 

 erosion of the Szechuan watercourses to a level many 

 hundi-ed feet below that of the original plain has failed even 

 now entirely to fill it up. Another striking fact is the very 

 recent formation of the existing landscape. In short — 

 China, the oldest cowitry politically, is geologically one of the 

 newest. This fact applies more especially to Central and 

 Northern China, within which were comprised, until recently, 

 the limits of the Chinese Empire. A few years more, 

 geologically speaking, and this and the other lake basins 

 \vill be entirely filled, and the whole sediment brought down 

 will be available for promoting the advance of the coast- 

 line, an advance even now so rapid that within the lifetime 

 of men now living Shanghai threatens to be left an inland 

 city unapproachable by tidal waters. This first lake is 

 formed by the damming-up of the river seawards by the 

 Wusueh range of hills, and is drained into the next lower 

 basins, that of the Nganhui province, by a comparatively 

 confined channel through which the river flows with a rapid 

 current — much as the Detroit River drains Lake Huron into 

 Lake Erie. 



The next lake bed, I take to be represented by the plain 

 north of Kiukiang, and the valley west of Nganking together 

 with the Poyang Lake region : this is again bounded sea- 

 wards by a cross range, through which the river has burst 

 its way, in the narrow winding rock-infested channel known 



s 



