A Napoleon III black marble mantle clock, circa 1889, with maker's mark with date for S. Marti et Cie; with key and pendulum, with an enamel chapter ring with Arabic numerals and a visible escapement set within a decorative bezel, the case with engraved and coloured spandrels, stylised floral motifs flanked by green onyx pillars and surmounted by a shaped arching pediment, upon an extended base, with onyx trims and floral details throughout, height 42 cm, width 35 cm, depth 16 cm