BRONZE, the name of a mixed metal, which the ancients employed for casting statues and other orna• ments. According to Vasari, the bronze of the Egyp tians consisted of two-thirds of brass, and one of cop per ; and-Pliny informs us, that the Greeks added to the brass one-tenth part of lead, and one-twentieth part of silver.
In casting bronze figures, particular attention must be paid to the formation of the mould. The pattern from which the cast is to be made must have a mould made upon it, with a mixture of one-third of plaster of Paris, and two-thirds of brick-dust. Its thickness should be proportioned to the weight of the figure ; and small air-holes, opening upwards, should be made in the joints, to give free passage to the air, which is thrust out by the entrance of the metal. Over the intcrior surface of the mould there should be spread neatly a layer of clay of the intended thickness of the metal.
When this is done, the concavity, which is bounded by the layer of clay, is to be filled with the composition of plaster of Paris and brick-dust already mentioned, which will form the core. When the figure is long, strong bars of iron must be laid in the mould as a support to the metal figure, and round these the core must be cast. The mould is then opened, the layer of clay taken, and every kind of dampness expelled, by drying the mould and core with charcoal or lighted straw. The core is then replaced in the mould, where it is sup ported in its proper position by short bars of bronze, which run through the mould into the core. The mould being strongly lortified with iron bars, and fixed in a right position, the liquid bronze is poured into the mouth of the mould. (9r)