The present watch is an extremely rare example of a relatively small twelve months timekeeper, built to run during one year on one winding. Consequently, the barrel is exceptionally large and contains a very strong mainspring. The fusée is very high to accommodate the twenty-four turns in its groove.
Timepieces with one year going movements are also called four hundred day clocks and much more common to find in form of a large clock due to the size of the movement.
Etienne Tavernier (1756-1839) is listed in Tardy's Dictionnaire des Horlogers Français as famous watchmaker located in Paris who worked closely with Abraham-Louis Breguet.
It is thought that Etienne Tavernier invented the astronomical watch key, containing a miniature watch movement featuring calendar and phases of the moon.