824 THE POPULAR SCIENCE MONTHLY. 



has conferred. The works were extended and added to from time 

 to time, and the construction of the canal Pe gave origin to a 

 popular song celebrating the benefits derived from canalization. 

 The transportation of rice by these artificial channels dates from 

 the third century, when the Emperor Min-Te had a canal con- 

 structed which added more than 300,000 acres of land to cultiva- 

 tion and was used for the transportation of arms and provision. 

 From this time there was more than enough food in China. 



The efforts of the Thangs in the sixth century were less re- 

 markable than those of their predecessors, because the more im- 

 portant enterprises had already been executed. The most note- 

 worthy of these was the excavation of a lake in 624 A. D. by the 

 celebrated poet Pe Ku I, who was also a prefect. It was supplied 

 by the Tsien Tang River, and watered a space of between 90,000 

 and 100,000 acres. The dam was solidly built, but permitted the 

 water to filter through in such a way as to fall slowly on the land 

 below the level of the lake. The bank, planted with peach-trees 

 and weeping willows, became a favorite promenade for literati 

 and poets. The lake was crossed by six bridges, beneath which 

 the flowers of the lotus waved, and the promenade was the first 

 water-side pleasure-walk that existed in China. This lake was 

 enlarged under the Sung dynasty by the poet Sou-Tong-Pao, who 

 added what is called the outer lake. New dams were built, and 

 travelers who resort to the lake are still able to admire the beauti- 

 ful as well as useful work of the two great poets, who enjoyed 

 also the rare privilege of being great engineers. 



The Sung dynasty, in the ninth century, desiring largely to 

 extend the system of canals, created a new department, at the 

 head of which was placed a minister called the Governor of the 

 Waters. Besides this, a superintendent of the transportation of 

 rice was appointed to administer the northern provinces of the 

 Yellow River, to whom were assigned the study of the regimen of 

 the waters and the food-needs of the provinces, the classification 

 of productive lands according to their value and position, and the 

 supervision of the mulberry culture. This was the second period 

 of Chinese agricultural prosperity. Another improvement was 

 introduced in the tenth century, when sluice -dikes were in- 

 vented which could be closed in times of flood and opened in 

 dry seasons. 



An overflow of the Tai Hu River in the province of Su Chiu, 

 in 1160, moved the censor Li Kie to propose three projects to the 

 throne : To make sluices and dams ; to establish competitions 

 among officers and others in plans for hydraulic works ; and to 

 take advantage of the fall and winter seasons of low water, when 

 the people were not engaged on their farms, to employ them in 

 constructing the works. The propositions were accepted, and the 



