In the estimation of the Chaldaean architects, stone was a material of secondary consideration: as it was necessary to bring it from a great distance and at considerable expense, they used it very sparingly, and then merely for lintels, uprights, thresholds, for hinges on which to hang their doors, for dressings in some of their state apartments, in cornices or sculptured friezes on the external walls of their buildings; and even then its employment suggested rather that of a band of embroidery carefully disposed on some garment to relieve the plainness of the material. Crude brick, burnt brick, enamelled brick, but always and everywhere brick was the principal element in their construction. The soil of the marshes or of the plains, separated from the pebbles and foreign substances which it contained, mixed with grass or chopped straw, moistened with water, and assiduously trodden underfoot, furnished the ancient builders with materials of incredible tenacity. This was moulded into thin square bricks, eight inches to a foot across, and three to four inches thick, but rarely larger: they were stamped on the flat side, by means of an incised wooden block, with the name of the reigning sovereign, and were then dried in the sun.* A layer of fine mortar or of bitumen was sometimes spread between the courses, or handfuls of reeds would be strewn at intervals between the brickwork to increase the cohesion: more frequently the crude bricks were piled one upon another, and their natural softness and moisture brought about their rapid agglutination.** As the building proceeded, the weight of the courses served to increase still further the adherence of the layers: the walls soon became consolidated into a compact mass, in which the horizontal strata were distinguishable only by the varied tints of the clay used to make the different relays of bricks. * The making of bricks for the Assyrian monuments of the time of the Sargonids has been minutely described by Place, _Ninive et l’Assyrie_, vol. i. pp. 211-214. The methods of procedure were exactly the same as those used under the earliest king known, as has been proved by the examination of the bricks taken from the monuments of Uru and Lagash.