In order to avoid destructive floods at the time of the yearly inundation, in order to bring about a graduated and regular rise of the Euphrates, in order to receive the overflow in the years when the inundation was higher, and apply the water thus stored in the years of drought,--in a word, in order to have the water of the Euphrates completely under control, Nebuchadnezzar took in hand, and completed, one of the most magnificent of hydraulic works. Above Babylon, and the four canals which connect the Euphrates with the Tigris on the northern border of Babylonia proper, lay the ancient city of Sippara (I. 257). Near this, on the eastern bank of the Euphrates, was excavated a vast basin, not inferior to the artificial lake of Amenemha. The circuit of this basin is said to have been 420 stades (_i.e._ 50 miles); the depth reached 35 feet. The trenches and dams, which formed this basin, were cased, on the inclines, with masonry, and the excavated earth was used for the embankment of the Euphrates. According to the excerpt in Abydenus, Berosus allowed a circuit of 40 parasangs, _i.e._ 150 miles, for this basin, with a depth of 20 fathoms, and added that the sluices, which opened and shut of themselves, according to the level of the water in the basin of the Euphrates, irrigated the level land. If the circuit of the basin was really 50 miles, we must suppose that here, as in the lake of Amenemha, a low-lying strip of land was changed by embankment into a basin or wide reservoir.[686] With this great undertaking were connected other hydraulic works erected at Ardericca. At this place Nebuchadnezzar caused a new bed to be excavated for the Euphrates, with sharp curves, either to lessen the force of the current, and make navigation up the current possible, or, which is more probable, because it was necessary to moderate the flow of the river in order to conduct the inundation into the basin at Sippara.[687] By means of this basin at Sippara Nebuchadnezzar really brought the Euphrates into his power. Even though the excess of the water of the stream might be too much for its large dimensions in any single year, the canals leading to the Tigris provided the means of carrying off the excess into that river, and at the same time it was possible owing to the connections to counteract by means of the Euphrates the inequality of the water in the lower Tigris.