A gilt-bronze mystery clock, Jean Eugène Robert-Houdin, French, circa 1845

bell striking movement No.128 with silk suspension inscribed Brevet D'Invention and concealed in the base, a driving rod passing through the top of the case to engage with a single gilt arrow hand at the centre of a 4½-inch glass dial, the case similarly inscribed and numbered with reeded scroll foot supporting a rectangular plinth below a bombé-sided section applied with a bird and foliate scroll mount surmounted by a demi-column flanked by gryphons, the dial supported on two scroll arms, one of which contains the driving rod for the hand, the whole raised on a velvet and giltwood plinth, with an ebonised base inlaid with brass stringing

For a detailed history of Jean Robert-Houdin and his fascinating creations see Derek Roberts Mystery, Novelty & Fantasy Clocks Schiffer Books  1999; chapter 19 pg.219