Mirror Disk, ca. 1352–1336 BCE
Unknown maker, Tell el-Amarna, Egypt
Bronze, 6 1/8 × 5 1/2 × 1 in. (15.5 × 14.2 × 2.6 cm)
Restored, 1939; conserved, 1997, 2007, and 2012
Brooklyn Museum, New York City, gift of the Egypt Exploration Society, 25.886.1 

Seated Statuette of Isis Holding Horus, 332–30 BCE
Unknown maker, Ptolemaic Kingdom, Egypt
Bronze, 14 × 3 5/8 × 5 3/4 in. (35.6 × 9.2 × 14.6 cm)
Electrolytically treated, 1932–35; restored, 1940; conserved, 2002 and 2006
Brooklyn Museum, New York City, gift of the Egypt Exploration Society, Museum Collection Fund, 11.682

Although this ancient Egyptian mirror predates the seated statuette of Isis holding Horus by a millennium, both items have a similar black-brown appearance. Records show that they were electrolytically cleaned by a restorer in the early twentieth century, a process that removed layers of patina and corrosion, resulting in their present stripped surfaces. Now deemed an unconscionable removal of age in an item, this technique is employed only in localized areas and to different ends. Whereas their previous surfaces told the story of their past, the surfaces now tell the history of metal conservation practice in the early twentieth century.