Abstract
Man-nen-dokei, which is a historic perpetual chronometer, was made by Hisashige TANAKA at 1851. It is said that Man-nen Dokei is one of best works in "wa-dokei", Japanese traditional clock. Recently, it has been disassembled and restored in a national project, so we investigated the mechanism of the Man-nen-dokei in cooperation with the project. This paper shows the mechanism of the celestial globe at the top face of Man-nen-dokei. Especially, we focus on (1) the mechanism for simulating the motion of the sun and the moon throughout the year, (2) the relationship between the definition of "mutsu" and the "shinkon-sai" in the celestial globe.
