A Napoleon III black slate drum head mantle clock, mid 19th century, with maker's mark for Marti et Cie. the clock having a black chapter ring with gilt Roman numerals and a visible escapement set within a decorative bezel, with side volutes delicately engraved and gilt decorated with tendrils upon a similar plinth base, trimmed to the head and plinth with mottled amber marble borders, with key and pendulum. Height 30.5 cm. Width 54 cm. Depth 15 cm