This spring-driven table clock shows the time according to the Japanese 'temporal hours' system, in which the length of a day-hour is different from that of a night-hour and both vary according to the season of the year. The layout of this timepiece is unusual in that the movement of the indicator is in a straight line and not a rotation. Once the timepiece is wound up, the indicator moves slowly past the adjustable numerals over a 24 hour period. The timepiece is contained in a porcelain case which is painted with illustrations of the animals asociated with the Japanese hours.
© Science Museum / Science & Society Picture Library