Maker, Unknown, probably English. c.
1870. Movement 16.5"h x 6"w x 5"d. / 23.5"h x 9"w 6"d over
dome. Similar in many respects to a clock illustrated in British Skeleton Clocks,
Derek Roberts, pg. 255 and signed, Joyce, London. Pinwheel with one-half seconds
pendulum and coup perdu (French for 'lost beat') escapement resulting in a seconds beating
system. Eight day duration.
Click on pictures for more detail.
Movement has five overlapping dial rings for seconds, minutes, hours, 24 hour and
rotating moon indicating phases. The tall, slender frame is held by only three turned
pillars. Escapement has an over-sized pinwheel with 60 pins. Moon driven by a combination
of contrate wheel / worm gear combination driven off second wheel. Movement held by
polished and blued screws throughout. The large polished surfaces of the base holding the
rest of the movement create an interesting reflective movement in opposition to the actual
movement of the pendulum bob.
A coup perdu escapement converts a 1/2 second beating pendulum to directly control an
escape wheel at the rate of a one second pendulum, so only every other beat is registered
by the escape wheel. Hence the 'lost beat' moniker. It is an escapement with only
one impulse pallet, the other being hinged to the escape anchor; allowing the escape tooth
to pass without advancing the wheel. This design was invented by Jean-Baptiste
Dutertre, France, c. 1720's.
Provenance: Christie's, London UK, July 1, 2005; Lot #51. A very similar clock was auctioned at Sotheby's, London,
June 3, 1994, lot# 373. Maker unknown.