The Assyrians and Babylonians made almost exclusive use of brickwork in erecting the vast piles of buildings the shapeless ruins of which mark the site of ancient Nineveh and of the cities of the valley of the Euphrates. Their bricks, it is believed, were entirely sun-dried, not burnt to fuse or vitrify them as ours are, and they have consequently crumbled into mere mounds. The Assyrians also used fine clay tablets, baked in the fire--in fact, a kind of terra cotta--for the purpose of records, covering these tablets with beautifully executed inscriptions, made with a pointed instrument while the clay was soft, and rendered permanent by burning. We don't know much about Greek brickwork; but it is probable that very little brick, if any, was made or used in any part of Greece, as stone, marble, and timber abound there; but the Romans made bricks everywhere, and used them constantly. They were fond of mixing two or more materials together, as for example building walls in concrete and inserting brickwork at intervals in horizontal layers to act as courses of bond. They also erected buildings of which the walls were wholly of brick. They turned arches of wide span in brickwork; and they frequently laid in their walls at regular distances apart courses of brick on edge and courses of sloping bricks, to which antiquaries have given the name of herring-bone work. The Roman bricks are interesting as records, for it was customary to employ the soldiers on brick making, and to stamp the bricks with names and dates; and thus the Roman bricks found in this country give us some information as to the military commanders and legions occupying different parts of England at different periods. Flue bricks, for the passage of smoke under floors and in other situations, are sometimes found. The Roman brick was often flat and large--in fact, more like our common paving tiles, known as foot tiles, only of larger size than like the bricks that we use. They vary, however, in size, shape, and thickness. Not a few of them are triangular in shape, and these are mostly employed as a sort of facing to concrete work, the point of the triangle being embedded in the concrete and the broad base appearing outside. After the Roman time, brick making seems to have almost ceased in England for many centuries.