Pocket watches · Complication
Moon-Phase Pocket Watches
Partially verifiedWatches displaying the current phase of the moon, typically through a rotating disc visible in a dial aperture.
Mechanism
A wheel with 59 teeth, advanced by one tooth per day, rotates a disc bearing two moon images so that a full cycle of phases appears roughly every synodic month.
Typical characteristics
- Painted or engraved moon disc showing two moons
- Aperture in the dial, often at 6 or 12 o'clock
- Frequently combined with calendar functions
Identification characteristics
- Moon aperture and disc visible on the dial
- Accuracy of the moon-phase train (some approximate, some highly precise) varies by maker
Collector significance
A decorative and astronomical complication frequently paired with calendar work on higher-grade watches.
Known variations
- Simple moon phase
- Precision moon phase (long-cycle accuracy)
Photographs
Photographs are illustrative examples of the type, not necessarily the exact object described. Verify details against the source file page.
Sources & references
- General horological surveys
Where sources disagree, the disagreement is stated rather than resolved silently.