Millions of pocket watches still exist in drawers, safes and museums. During the life of many, their gold cases were often melted down, their material value being higher than the value of the actual pocket watch. Untold numbers were destroyed, but many still remain, vestiges of a by-gone era.

Here is one that although unexceptional in many ways, has one element that sets it apart from 99.9% of all others. Its endless screw winding mechanism.

The endless screw, the spiralling, twisting column meshes directly with the ratchet wheel winding up the mainspring sitting in the barrel. It is turned by the winding stem that in turn rotates the lower sliding clutch that engages with it.

The system is more often found in horological textbooks more than modern watches. There have been in recent year companies who have adopted the system for different functions, but they remain rare. The system was curious but expensive to produce and required considerable space; as a result, it was not commonly used; it does remain however, another detail in watchmaking history.

Thanks to the The K&H Watchmaking Competence Centre for the loan of this watch.