Abstract
Man-Nen Dokei, which is a historic perpetual chronometer, was made by Hisashige Tanaka, who founded the predecessor of Toshiba Corporation, at 1951. It has six multi-functional clock faces and a celestial globe. It is said that it runs for almost a year with just a single winding. Man-Nen Dokei was disassembled and restored in a national project. We have investigated on the mechanism of Man-Nen Dokei in cooperation with this project. In this paper, we report on the mechanism of the power supply. As a result, the structure of the power supply was clarified, and from the mechanism composition, it has been understood that the maximum continuous operating days are about 225 days and the fusee composition had not been optimized for the power supply.
