This a a very unusual double wheel movement in an exceptionally large silver case.
The watch requires some work, but is running.
MOVEMENT : Substantial gilt movement, very plain with no engraving or ornamentation.
Balance with ruby endstone, and going barrel (no fusee).
The watch runs for 24 hours (losing about 3 minutes per hour) when placed face upwards, but stops when face down.
DIAL : Large white enamel dial, signed and with subsidiary seconds. In very fine condition, with just a few surface scratches. Steel Breguet style hands. The hour hand has been repaired and the minute hand is loose (square hole needs to be reduced).
CASE : A heavy silver case with signed (and dated 1839) gilt cuvette. French silver marks on the stem and back cover. There are a few light scratches but the silver is in good condition, the hinges are fine and the covers and bezel all snap shut correctly.
The crystal is in poor condition, with chips all around the edge. This needs to be replaced (about 63 m).
This rare escapement was invented in France in 1704 by Debaufre, but not used in any volume until the early 19th century. The escapement uses two steel escape wheels acting alternatively on a single steel roller. Driven directly by a going barrel rather than a fusee as the escapement is not affected by variations in power.