Japanese lantern clock

Japanese wadokei lantern clock, unknown maker, c.1850. Weight driven brass clock with double verge and foliot escapements used to display unequal hours. Both verge staffs are suspended by a thread and the change from day to night foliot takes place automatically, but the time of the day and night periods had to be varied according to the season by moving the weights along the notched foliot. The clock has striking, going and an alarm mechanism and also has two calendar apertures. The train wheels are brass with steel arbors and pinions. The dial plate and also the back and sides are engraved with a floral design. Presented to the Worshipful Company of Clockmakers by Smiths Industries Ltd, August 1968. Clockmakers' Museum No. 580.

Japan did not adopt ‘Western’ time until 1873. Before that Japanese clocks recorded the time in two parts: from dawn to dusk and dusk to dawn. Each part consisted of six hours, but because day and night varied in length according to the seasons, hours in each part were rarely the same length. This clock is equipped with two separate verge escapements, which could be set to keep time at different rates by moving the weights on the notched foliots and to switch automatically from one to the other. The clock is stylistically fairly late and therefore most likely to have been made in the period before 1873 when 'Japanese time' was abolished.