32 THE GROWTH OF THE YANGTZE DELTA 



which figure is in wonderful agreement with 1 mile in 

 60 years. 



The Canal System. — One of the most conclusive 

 evidences of the Yangtze having built up the delta on which 

 we live is the intricate canal system of the delta. See Plate 

 10a, 106 and 10c. 



The canals are either tidal or their waters are held back 

 by the great tidal influence at the mouth of their principal 

 outlets, the Whangpoo, the Liu Creek, etc. 



History of Tsungming Island. — The following dates are 

 based on statements made in the Chih or Prefectural Eecords 

 of Tsungminghsien, of which there have been nine editions 

 since the end of the thirteenth centurv. See Plates 11, 12 

 and 13. 



"In the first 'Wu Te' year of Kao Tsu, Emperor o~ 

 the T'ang dynasty (A.D. 618) to the south of the subpre- 

 fecture of Haimen, there suddenly rose from the waters 

 two islands which were named 'Tung Sha' (East Sands) 

 and l Hsi Sha' (West Sands). In A.D, 696 some fishermen 

 occupied them, and nine years later a town, 'Tsungming' 

 was established. 



"Some three centuries after their birth, these islands 

 commenced to disappear, but at the same time there was 

 formed a little way to the northwest a new one called Yao- 

 liu-sha. In A.D. 1102, the two banks Tung-sha and Hsi-sha 

 had completely disappeared and while that of Yao-liu-sha 

 was itself also being demolished piecemeal, a further island 

 rose in the N.E. and received the name Tung-san-sha (East 

 Three Bank) from three families which established them- 

 selves there. In 1222 Yao-liu-sha which still resisted the 

 destroying current had its name of Tsungmingchen changed 

 to that of Tienszuchang (Salterns given by Heaven) and in 

 1293 is was made a district (Chou) with the earlier name 

 of Tsungming. A walled town was erected in that year." 



A chart of these changes is published in the 1760 edition. 



The Eecords proceed to describe how the island of 

 Yao-liu-sha was steadily cut away on the south and built 

 up on the north, compelling removals of the city in 1352 

 and 1420 (five miles in the first case and three in the second). 

 The waters continued to encroach on the city and a third 

 migration took place in 1529, the inhabitants going to the 

 island Tung-san-sha which had remained firm. Here again, 

 however, the river eventually began to destroy the city 

 walls and the site was moved to a new island (Ping-yang- 

 sha), somewhat to the south of Yao-liu-sha. Finally the 

 same fate overtook this position and the fifty and last migra- 

 tion took place in 1583 to another new island S.E. of the 



