Maker, Ferdinand Berthoud, Paris, France, c. 1785. Three train pinwheel escapement, 1/2 second gridiron compensated pendulum on knife edge suspension, 30 second Robin remontoire, full perpetual calendar, epicyclical equation of time, moon's age and phase, quarter strike on solar time Chime and strike can be silenced. 25.5"h x 12.25"w x 10.75"d, (65 x 31 x 27.5cm)

Below we examine on a closer basis some of the complex details of the movement.