This elaborate timepiece demonstrates the level of astronomical knowledge of eighteenth-century French scientists. The large main dial is composed of overlapping circular plates and three hands that indicate the time with a twenty-four hour chapter ring, the months of the year and their zodiacal signs, the days of the lunar month, and the local time in various cities and parts of the world, including La Californie. The four smaller dials grouped above show the phases of the moon, a tidal calendar for the ports of Northern France, the days of the week, and the times of the eclipses of Jupiter's first moon, Io. On the top of the case, a gilt-wood orrery shows the relative positions and motions of bodies in the solar system.
Very few such elaborate clocks have survived to the present. Unfortunately this clock is no longer in working condition as the movement is entirely missing.