GEOLOGY — WILLIS. 219 



Depth of the filling. — Data for estimating the depth of filling of the 

 Bay of Peking are meager, but not altogether lacking. The depres- 

 sion is recognized as a sunken valley, sculptured by running water. 

 There are many examples of similar character and of like magnitude 

 in the neighboring province of Shan-tung, and some of these have 

 not been so filled as to hide the floor of the valley. The valley of the 

 upper Won- ho, near Lai-wu, east of T'ai-an-fu, is many miles across, 

 is nearly flat over considerable areas, and is diversified and bounded 

 by mountains which rise abruptly from it. The bed-rock is widely 

 exposed. Reasoning from this comparison, we may infer that the 

 slopes of the mountains about the Bay of Peking descend to a depth, 

 which is probably not excessive, beneath the plain, and are con- 

 nected by a comparatively fiat floor. The fact that so large an area 

 as the Bay of Peking has been filled by streams which, though of 

 considerable size, are not great rivers is an argument in favor of 

 comparatively moderate depth. At Peking it may be 1 ,000 feet from 

 the surface to bed-rock ; it probably is not 2,000 feet. 



THE WATERS OF PEKING. 



Siirfacezvaters. — A small stream, the Tung-mi, enters the city from 

 the northwest, feeds the canals and lakes in the Imperial City, and 

 flows away through the Chinese city to the Pei River. It has no 

 value as a source of water. Wells are numerous in Peking. Some 

 of the principal ones in use by the natives are seen on the streets. 

 The deep grooves made by the ropes in the stone curbing testify 

 to their constant and long-established use. They are shallow, are 

 supplied by percolation in the uppermost strata, including the sur- 

 face waters of the streets and houses, and are liable to go dry. 



On the site of the American legation two wells have been sunk in 

 the course of operations for building. The first proved inadequate. 

 The second, 100 yards from the first, was sunk 32 feet, at which 

 level water poured in in such amount that the work had to be stopped. 

 The bottom is reported by Mr. S. H. Nealy, the architect in charge, 

 as being a quicksand which had a tendency to flow to the southeast. 

 This well has not been lowered by any draft thus far made upon it. 



Japanese ' ' artesia?i ' ' wells. — Wells, which are artesian in the sense 

 that they reach flows beneath the surface waters, have been sunk by 

 the Japanese in Peking with marked success. Regarding these the 

 following facts have been ascertained : 



A well in the Presbyterian Mission Compound is fitted with a 

 windmill and is reported to yield a satisfactory supply. 



A well in the Belgian Legation grounds is said by the Belgian Min- 

 ister to be 60 meters (195 feet) deep, and to give excellent soft water. 



