Strip spring wrapped around the movement, which the striker of a repeating watch hits to make a gonglike sound. Breguet invented the gong spring in 1783, and it was a turning point in the history of watchmaking. Replacing the traditional bell, it considerably reduced the thickness of chiming watches. Soon adopted by the majority of watchmakers of his time, the gong spring sounded the death knell of the earlier bulbous “turnip” watches.
Breguet quarter repeating watch No. 4270, grande sonnerie in passing. Sold on July 9, 1825 to Mr Suzanne de Bréauté the Elder. The gong-spring can be seen along the inner edge of the caseband.