japanese double foliot wadokei

This clock came in for a simple disassembly, clean and relubrication. It has undergone major restoration in the past, and the owner runs it very rarely, so there was very little wear and no need for any material intervention.

Throughout the Edo Period (1603-1868), native Japanese clocks (wadokei) were built to display the ancient temporal hours system still in use throughout the country. The day was divided into two periods - daylight and night-time, and these periods were then subdivided into six equal hours, or ‘toki’. Consequently, except during equinoxes, daylight and night-time toki were of differing, and changing, lengths throughout the year, necessitating twice-daily regulation of the clock’s oscillator. This clock is an example of late 18th Century Japanese horological innovation, including the double foliot system with automatic changeover linked to the count wheel. This eliminated the need for daily regulation of the oscillators, instead they just needed adjusting approximately every 15 days to account for the seasonal changes in daylight length.