222 BR. Pumpelly on the Delta-plain of the Yellow River, 
Map No. 7 (Pl. 5) represents the courses, under the Sung 
dynasty, from A.D, 1048 to A.D. 1194, a period of 146 
river, and to the §.E. through the Sz river. Lake Lo appears 
from the observation of Clark Abel, and from Chinese meas- 
urements, to be about 150 feet above the sea. 
Map No. 9 shows the condition of the river under the Yuen _ 
and Ming dynasties, together with the Grand canal, a condi- 
tion which seems to have remained substantially the same till 
within the last ten or fifteen years. 
In early times the Yangtse entered the sea by three arms 
called the Sankiang, i. e., “Three Rivers ;” and Chin Hu Wei 
has given a map of these, founded on the opinions of early au- 
thorities. I have indicated them on map No. 1 of the series. 
A glance at the nine maps of the delta courses will show 
ow widely separated have been the limits of divergence of the , 
arms of the Hwang Ho, within the past 3000 years. A mighty. 
river, ever turbulent, subject yearly to an enormous increase 
in volume, an increase regulated rather by the amount of pre- 
cipitation in the distant Kwenlun mountains, than by the local 
climate, it has ever been the terror of the countless millions 
through whose midst it flows, 
From the earliest times an immense force has been at work 
to keep it from breaking through its dykes, or, when this has 
happened, to guide and retain it between new embankments. 
The quantity of solid material carried by the river and depos- 
ited along its course, is so great that its bed is rapidly raised, . 
and appears to have been, before the last change, higher than 
the adjacent country. . 
7 Biot says, “‘it is certain that the bed of the river, from Hwai- 
_ downfall of dynasties, this "seed. ek of the river has been 
turned to account as a weapon of offense, Breaking the em- 
bankments has been made to accomplish, almost instantane- 
ously, by the destruction of hundreds of thousands of inhab- 
itants, conquests that had been delayed by years of brave re- 
From the earliest time of colonization on the delta-plain, 
the task of keeping the Hwang Ho within its bed has been the 
constant care of the rulers of China, both when the country 
was united under one man, and when it has been subdivided 
