Discovering a Japanese lantern clock
The Japanese temporal system divides the day into 12 hours, rather than 24, and six of these “hours” are proportional to daylight and six to darkness. Hence, the adjustable numerals are designed to accommodate variable time intervals within the relative lengths of day and night by season.
The numeral characters are engraved with the traditional 9-4/9-4 numbering, using the zodiacal names of the hours, which count down in reverse order.
During the process of recording and documenting, a conservation approach was employed focusing on stabilising the clock in its current condition. Treatment included; fabricating missing parts and the mechanical removal of corrosion with a custom made mother-of-pearl scraping tool, a material that retains its shape but is softer than the substrate, so becomes sacrificial, reducing the risk of damaging the ironwork.
Considerations for future work include analysis of the brass alloys and the coating used on the ironwork, as well as investigating the lacquer present on the calendar wheel (pictured above) aiming to provide a more detailed narrative of the social and craft context surrounding the clock. Due to its age a stable environment and restricted running hours will be imposed on the clock to mitigate further losses.