和時計における不定時法自動表示機構 [in Japanese] The Mechanism of Automatic Display for the Temporal Hour in the Japanese Clocks [in Japanese]
Search this Article
In 2003, HASHIMOTO and TSUHIYA noticed a movement of Japanese clock in the survey on scientific historical materials at TAKEKAWA house in Matsuzaka city, Mie. In the investigation into this Japanese clock, it was understood that it is a lantern clock with the quite rare, automatic display for temporal hour as Japanese clocks. The myriad-year-clock, made by Hisashige TANAKA in 1851 who was called "Karakuri Giemon", has also the automatic display for temporal hour. Meanwhile, SASAKI had investigated into such Japanese clocks and gathered informations about automatic display for many years. The trial for such kind of automatic displays for them started in the late Edo period. And the improvements of the accuracy for time keeping and of the operationally of them are very interesting for us because they show the characteristics of the technical development in them. We have investigated into 9 cases in 4 kinds of automatic display mechanisms and calculated the numbers of days for annual motion in gear trains. As the result, it has been revealed that the tooth number 73 of the annual gear was very convenient and important to fix the numbers of days for annual motion of their mechanisms.
- Bulletin of the National Science Museum Ser. E Physical Sciences & Engineering
Bulletin of the National Science Museum Ser. E Physical Sciences & Engineering 28, 31-47, 2005
National Science Museum