Boulleter

Boulleter is a term with a specific meaning within the field of horology, referring to a type of clock movement that utilizes a going barrel. This going barrel incorporates the mainspring and the first wheel of the gear train, which are housed together in a single, rotating barrel. As the mainspring unwinds, it directly drives the barrel, which in turn powers the rest of the gear train. This design differs from clock movements where the mainspring is anchored to a fixed arbor and its unwinding directly drives the first wheel. The boulleter system is known for its relatively simple construction and was a common feature in many early mechanical clocks and watches. Its design allows for a more compact arrangement of the initial part of the gear train. The term itself is derived from the French word "boule," meaning ball, likely referring to the rounded shape of the barrel. While not the most complex mechanism, the boulleter represents a foundational element in the development of mechanical timekeeping devices.