Page:History of Art in Phœnicia and Its Dependencies Vol 1.djvu/399

TOWNS AND HYDRAULIC WORKS. 377 walls do not describe a circle but a regular polygon, whose visible part rises from twenty-three to twenty-seven feet above the ground. The contiguous reservoir is smaller ; its diameter is not more than from twenty-four to twenty-eight feet, but it is rather deeper than the other. At the point of junction there is a perpendicular slit, about sixteen inches wide, which descends almost to the floor, and allows the water to flow from one cistern into the other. At the ground level a number of openings allowed the rain to pour into the larger reservoir, where they deposited the earth, sand, leaves, and other matters held in suspension. After the rains were over the sluice was opened and the water allowed to flow gently into the smaller reservoir, the whole thus acting as a FIG. 255. Plan of cistern. From Daux. huge filter. The sluice was then reclosed and the water carried in leather buckets to the thirsty cattle. The weight of water inclosed in these basins exerted a very strong thrust against their walls, and, warned no doubt by the destruction of those first erected, the builders took precautions against accident which seem to have been effectual in spite of their naivett. At the points where the short stretches of straight wall joined each other, strong buttresses were erected, both within and without. To give our readers a clear idea of how this contrivance was arranged we here insert a plan of the large basin (Fig. 255), a cross section of the wall (Fig. 256), and an elevation of part of its VOL. i. 3 c