Herodotus observes that in Babylonia the river (Euphrates) does not overflow into the fields spontaneously, as in Egypt. It is not so active as the Nile, and the water has to be raised artificially by hand, and by wheels.[418] The provision of a sufficient supply of water for the land was not neglected by the kings. We have already seen (p. 261) that king Hammurabi boasted to have supplied Sumir and Accad with water for ever. The canal system of Babylonia began about 150 miles above the metropolis.[419] The main object was to protect the plain from the rapid floods of the Euphrates by dams, and to moderate the flow of the inundation. Reservoirs were required to receive the water of the overflow, and preserve it against the time of drought. It was also necessary to carry the water as far as the middle of the plain, which in ordinary years it failed to reach, to form a network of canals to convey water from the Euphrates even when there was no inundation, and finally to dig trenches to remove the water from districts where it lay too long, and to drain the broad marshes on the lower river near the mouth of the Euphrates. From the inscription of Hammurabi, and the numerous remains of dams and canals, we may conclude that the kings of Babylon constructed large and comprehensive works of this kind, which were of use not in agriculture only, but for commerce also. The brief duration of the later restoration of the kingdom could not allow time to complete the greater part of the vast structures and conduits, of which traces and ruins are still in existence. The canal Naarsares, which was carried from the Euphrates above Babylon toward the west, and ran parallel to the stream till within a short distance of the mouth; the canal Pallakopas, which was derived from the main stream 100 miles below Babylon, and emptied into the Chaldæan lakes, in order to convey to them the excess of water from the Euphrates; and three junction canals above Babylon between the Euphrates and Tigris, from which trenches branched off for irrigation, appear to belong to the time of the ancient kingdom (see below). These labours of the princes, the numerous dams and "waters of Babylon," attained their object. Babylonia was a garden where the land brought forth more abundant fruits than in Egypt.