has conferred. The works were extended and added to from time to time, and the construction of the canal Pé 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 constructed which added more than 300,000 acres of land to cultivation 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 remarkable than those of their predecessors, because the more important enterprises had already been executed. The most noteworthy 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 beautiful 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 invented 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