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THE POPULAR SCIENCE MONTHLY 





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Fig. 4. Low Isolated Mountain 

 Geoup in Northeastern China. 



Pig. 5. Two Farmers Raising 

 Water from the Grand Canal into 

 the Head of an Irrigating Ditch by 

 means of a Wicker Basket slung 

 between them. 



Fig. 6. A wide River Plain among 

 the Mountains of Shan-tung. The 

 bridge of stone slabs across the sand- 

 laden river is part of the principal 

 wheel-barrow road of the valley. 



Fig. 7. A Typical City Wall, with 

 Gate Tower. 



termined largely by the rocks of which it consists, partly by the climate 

 to which it has been subject, but chiefly by the geologic events which 

 have occurred during its history. Of course the beginnings of that his- 

 tory are unknown, just as the human history of China shades into 

 darkness when we attempt to trace it back into the remote ages. But 

 the present features of the land are chiefly due to the later events in its 

 life, and these have been partly worked out by the geologists who have 

 explored its surface. 



"We may take as a convenient starting point for our interpretation 

 a time far back in geologic chronology 1 when China was a land surface 

 which had been exposed to erosion so long that nearly all the hills and 

 mountains that may have existed there before had been worn away, 

 leaving a relatively flat plain with groups of low hills here and there. 

 The rocks beneath this plain were of various kinds, most of them highly 

 folded. Eventually this surface was submerged beneath a compara- 

 tively shallow inland sea, and although the uneasy movements of the 

 earth's body caused the sea bottom to emerge occasionally, it remained 

 below the water nearly all through the geologic periods which consti- 

 tute the Paleozoic era. By the end of that time we may picture China 

 as a shallow sea bottom rising very gradually to a marshy coastal plain 

 on the east. During the long intervening ages the accumulation of sedi- 

 ments upon the sea bottom had formed successive layers of limestone, 



1 Just before the Cambrian period. 



2 Jurassic period. 



