196 RESEARCH IN CHINA. 
of gravel and sand occur adjacent to tributaries of the Fén-ho. The upper 
surface of the deposit near P’ing-yang-fu lies about 80 feet, 24 meters, 
above the river, and throughout the valley rises gently to the mountains, 
east and west. Northward it is continuous with the surface descending 
from the upland of the Si-yau-ling, and southward it sinks to the level of 
the present alluvial plain of the Fén-ho, at its junction with the Kii-ho. 
In the shallow sections to the south of the Kii-ho, snail shells are especially 
abundant. 
The continuity of surface, constitution, color, and structure, from 
the upland north of Ho-chéu to the lowlands south of P’ing-yang-fu, mark 
the Huang-t’u of the Fén-ho valley as a uniform deposit, which is through- 
out of alluvial origin, except where local conditions have determined the 
gathering of loess drifts from the alluvium. That the deposit is in part 
of earlier age and in part of current deposition is a fact which is of more 
than local significance. The Huang-t’u has been a continuous and con- 
tinuously moving formation since its inception. 
The conditions of accumulation of the Huang-t’u formation are 
intimately related to physiographic aspects of the region in which it now 
occurs, and of central Asia whence the material was derived. ‘The reader 
is accordingly referred to the discussion of physiographic stages, where the 
origin and development of the Huang-t’u are considered under the head 
of the Hin-chéu stage (see Chapter XI). 
ARTESIAN WATERS OF THE BAY OF PEKING. 
THE SITUATION OF PEKING. 
Before entering upon the investigation, of which the results are stated 
in the following pages, the writer deemed it improbable that a supply 
of good water could be obtained at Peking by a deep well. Accepting 
von Richthofen’s theory that the Plain of Peking was composed of mate- 
rial chiefly carried and deposited by wind, he saw no opportunity for 
the occurrence of strata of coarse and fine material, such as are favorable 
to artesian conditions; but the facts observed are convincing evidence of 
the fluviatile formation of the plain and of its heterogeneous bedded 
character. Good water is found by wells 200 feet deep, and all the 
desirable conditions of an artesian fountain may probably be secured by 
a well 1,000 to 2,000 feet deep. In the absence of any supply of whole- 
some water, such a well is of vital importance to the American Legation, 
and, as demonstrating the resources within reach, would be a boon to the 
entire city. 
