Physical Dimensions: overall: 15.2 x 16.3 cm (6 x 6 7/16 in.)
Provenance: Purchased in Madrid in 1849 by William Stirling-Maxwell [1818 - 1878], London (from an album with his device and bookplate as William Stirling). (Bernard M. Rosenthal, Inc., New York); purchased 1960 by Lessing J. Rosenwald; gift to NGA, 1964.