Jean-Eugène Robert-Houdin Paris Mystery clock Wood, bronze, glass, crystal, brass, fabric. Height: 48 cm. Width: 15 cm. Circa 1860 The dial at the top of the clock is supported by a pair of griffins. Under them is a cylindrical crystal column, held by an urn also flanked by griffins. The whole piece sits on a fabric-covered base which was originally crimson. The circular glass dial has Roman numerals for the hours and a single hand to give the hours. The mystery lies in the fact that the dial has no visible gear train and that the transmission from the movement to the dial is invisible. The movement, which is fitted in the base, has an hour and half-hour strike and a cylinder escapement. It is connected to the dial as follows: the crystal column is fitted with a tube that has a toothed wheel at each end. The tube turns, transmitting the movement through the two griffins to a moving glass disk set with a toothed wheel carrying the hand. This disk is placed in front of the dial. Clockmaker Jean-Eugène Robert-Houdin (1805-1871) worked hard on perfecting his art, as illustrated by the numerous patents he took out as well as by his production of automata which appeared in many celebrated magician acts. Several of his mystery clocks have been preserved and testify to his taste for clockmaking and conjuring. One famous example can be found at the Museum of Magic in Blois, France, which is largely devoted to his work.