Watch with portrait of Friedrick Wilhelm, the Great Elector

Swiss, geneva case with german, berlin movement; watch; horology. Date: case ca. 1688, movement ca. 1750. Dimensions: Diameter (case): 1 9/16 in. (4 cm); Diameter (back plate): 1 1/4 in. (3.2 cm). Medium: brass, painted enamel on gold, steel. Collection: Metropolitan Museum of Art.