IRRIGATION (ante). Some of the ancient works for irrigation were stupendous. The canal of the Pharaohs, which connected Pelusium with the Red sea, was an irrigat ting canal. There existed a work in Arabia, probably long before the time of Solomon, which, in some respect-z, excelled all works of the kind, modern or ancient, and corre sponds weli with the fact that the Arabians were among the first mathematicians. In Yemen, Arabia, them was an immense reservoir for holding water for irrigating the valley of Mare). This reservoir was made by a dam 2 m. long and 120 ft. high. It was constructed of immense blocks of ashlar, and was so durable as to serve the purpose for which it was built more than 2,000 years. It then gave way, scattering ruin in the course of the torrent which it let loose. It must he borne in mind that one of the best examples of modern engineering is a dam in France across the Furens which is 164 ft. high, but only 328 ft. wide at the top. This work almost sinks into insignificance when compared td the ancient Arabian dam. It may, perhaps, be presumed that there is some exaggeration in the statement regarding the ancient work, but a reasonable allowance must leave it as one of the most stupendous engineering works of which we have any record. The plains of Assyria and Babylonia were intersected with a system of canals both for irrigation and navigation. In many of them the water was raised by mechani cal means somewhat lake that practiced at present in Egypt. The ancient Peruvians and Mexicans constructed immense aqueducts for irrigation purposes. The system of irrigation practiced 'in Lombardy at the present time, and derived from the ancient Romans, is the cause of the wonderful fertility of that country. The distribution of the waters of all the rivers of Lombardy is held by the government, and is rented for periods of time to the horticulturists and agriculturists. Channels are made for leading the
water from the rivers, and from these secondary channels are constructed, about 24 ft. apart. In summer the water is allowed to flow only a few hours during each week, but from Oct. to April the flow is steadily kept up, except during grass-cutting. The lands thus irrigated well repay their owners for the outlay by the increased rent received, which is about one-third more, while the yield is double. The cultivation of rice can be successfully carried on only with irrigation, and the best lands are therefore found on the alluvial flats bordering rivers. The land is intersected by ditches, along which there are embankments supplied with gates, so that the water in the ditches may be raised above the level of the fields, and flowed upon them at pleasure. The rice is planted in trenches and lightly covered, and then the water is let on and kept there tor from 4 to 6 days, or when the grains swell and begin to sprout. It is then let off till the sprouts arc 2 or 3 in. above the ground, when it is let on again for about the same space of lime. Then it is drained off, and after a time the rice is cultivated with a hoc. • In from 0 to 8 weeks the water is again let on for 2 weeks, for the first 4 clays to a con siderable depth, after which it is gradually let off. See RicE. Considerable attention is paid to irrigation in our western territories and California. The facilities are usually great, as elevated mountain streams may generally be used as som•ces, whence the water finds its way by gravity wherever it is directed