A Napoleon III black marble mantle clock, 1850-1870, with maker's mark for S. Marti et Cie, the elegant plinth style case enclosing an enamel chapter ring with Roman, numerals and a visible escapement, raised upon an extended base with verde, antico decoration to the cusped edges, with key and pendulum, height 33 cm, width 28 cm, depth 14.5 cm