FACT OF THE DAY

The escapement so smooth it skipped the oil

The detent escapement, refined by John Arnold and Thomas Earnshaw around 1780, has so little sliding friction at its locking surfaces that it needs little or no oil there at all. That was a big deal in an era when oils thickened, dried, and drifted over months at sea, quietly ruining a watch’s rate. Unlike the lever escapement in most mechanical wristwatches, the detent gives the balance a push only once per full swing, and otherwise leaves it largely alone to do its thing — less interference, better timekeeping, which is why it became the classic choice for marine chronometers.

According to Wikipedia, Arnold’s small 1782 chronometer paired a detent escapement with a clever balance spring setup and reportedly kept time to roughly 1 to 2 seconds a day.

Sometimes the smartest move is knowing when to leave things be.