Page:A History of Art in Chaldæa & Assyria Vol 1.djvu/168

148 A HISTORY OF ART IN CIIALD.I-:A AND ASSYRIA. these retaining-walls. The average diminution is from seven to ten feet at the base, to from three to six at the top. The constructor showed no less skill in the use he made of his stretchers and headers. They not only gave him an opportunity of safely diminishing the weight of his structure and economising his materials, they afforded a ready means of adapting his wall exactly to the work it had to do. The headers penetrated farther into the crude mass within than the stretchers, and gave to the junction of the two surfaces a solidity similar to that derived by a wall from its through stones or perpenders. In describing this wall, M. Place also calls attention to the care with which the angles are built. " The first course," he says, ' is composed of three ' headers ' with their shortest side outwards FIG. 46. Elevation of wall, Khorsabad ; from Place. and their length engaged in the mass behind. Two of these stones lie parallel to each other, the third crosses their inner extremities." Thanks to this ingenious arrangement, the weakest and most exposed part of the wall is capable of resistino- any attack. The surface in contact with the core of crude brick was only roughly dressed, by which means additional cohesion was given to the junction of the two materials ; but the other sides were carefully worked and squared and fixed in place by simple juxtaposi- tion. The architect calculated upon sufficient solidity being given by the mere weight of the stones and the perfection of their surfaces. 2 1 PLACE, Ninive, &c. vol. i. p. - Ibid. p. 33.