Brick

—A rectangular block of elay, moulded to regular sizes, and burnt to give it hardne and durability. The usual sizes average 84x44x2. The color of bricks de pends upon the amount of ferric oxide in the clay, ranging from white with 1%, through buff and orange, to a deep red with 6%. Common bricks are made from a marly ot sandy clay or an artificial marl, termed malm, made by mixing chalk with the clay.