Technically, bronze is an alloy of copper and tin; in Egyptology, the term bronze is often used to include a wide variety of alloys—such as arsenical copper and copper with additions of lead and of nickel. Since several metals occur in nature as impurities in native copper, the determination by archaeologists of intentional alloying has been difficult, particularly with respect to the first use of bronze in ancient Egypt. Copper ores seem to have been imported into Egypt from a variety of sources, including Cyprus, the Sinai, Southwest Asia, and, possibly, Nubia. Cast copper and hammered copper objects were made in Egypt from the Predynastic period onward. From the Old Kingdom, life-size statues of Pepy I (r. 2354–2310 BCE) and his son are the earliest surviving large-scale works in hammered copper; the composition of the sculpture was analyzed at 98.20 percent copper, 1.06 percent nickel, and 0.74 percent iron.
Copper's casting ability can be improved by the addition of tin—this reduces shrinkage, inhibits porosity, lowers the firing temperature, and increases fluidity. The resulting alloy, bronze, has the advantage of being harder and stronger than copper. Despite the obvious superiority of bronze, a longtime overlap continued for the use of copper alongside bronze in Egypt from the Middle Kingdom through the New Kingdom. Copper and bronze, regardless of their various respective properties, were used indiscriminately for similar objects. There seems, as well, to be some confusion in Old Egyptian terminology, with bἰʒ (“copper”) being used for ḥsmn (“bronze”).
A large furnace was discovered at the site of Kerma in Sudan, which was dated to the Second Intermediate Period. There, copper was the principal metal in use. An even larger and more elaborate foundry was discovered at the Ramessid capital of Qantir in the Nile Delta. Similar in style to the Kerma furnace, a long trench was flanked by perpendicular channels for tuyeres (a nozzle through which air is delivered). Associated with that find were crucibles, molds, tuyeres, and finished pieces, particularly trappings for horses. Both furnaces were largely for casting, rather than smelting, as most copper was imported in ingot form.
A scene in the tomb of the vizier Rekhmire at Thebes depicted the casting of a set of doors for the temple of Karnak. Simple open-face molds were used to make tools and the surfaces of vessels were raised by hammering, but elaborate sculptures were often cast in multiple-piece molds, then assembled. The casting of such pieces was produced by the lost-wax process, or cire perdue, wherein a model would be made in wax over a core material, usually clay, and then encased in a clay mold. The wax would be melted off as molten metal replaced it. Significant amounts of lead added to the bronze would further increase the fluidity of the molten metal, allowing a finer casting. A large number of the bronze statuettes known from the Third Intermediate Period and later were produced in that way. Multiple-piece castings were assembled through mortise-and-tenon jointing, with cold hammering rather than soldering. Wood and other materials were employed as bases, into which sculptures could be set. Many statues were also gilt and inlaid—by cold hammering, by cementing in precast settings in the surface of the bronze, or by coating the surface with a layer of gesso and applying gilding to that. The last, a largely unsuccessful technique, was nonetheless widely employed.
- Lucas, A., and J. R. Harris. Ancient Egyptian Materials and Industries. 4th ed. London, 1998.
- Roeder, G. Staatliche Museen zu Berlin: Mitteilungen aus der Ägyptischen Sammlung, vol. 6: Ägyptische Bronzefiguren. Berlin, 1956. The most comprehensive work on ancient Egyptian bronzes.
Yvonne J. Markowitz and Peter Lacovara