All early Japanese clocks were based on the imported European “Birdcage” or “Lantern” designs. They were made of:
- Plain iron
- Plain iron, gold leafed and lacquered
- Plain iron lacquered black
- Plain iron damascened with gold or silver
- Plain copper and decorated in a similar way to the iron plates (but not damascened), also silvered.
- Brass, but this was not used for cases until the end of the 17th century.
- Some late clocks were brass decorated with cloisonné enamels.
The method of measuring “hours” by the fall of the going weight marked on the wall behind the clock, led to the construction of small purpose made clocks with integral indicator (known as Shaku-dokei from the unit of measurement “shaku” equating to approximately 300mm or 12ins. and were made mainly of Shitan (or Cedar) wood.
Time was recorded by means of clocks which only had one hand, which indicated the hours. This hand was stationary, while the dial moved, except in clocks and watches with an alarm, where the dial was stationary and the hand moved.
There were no divisions of the hours into minutes. On some pieces a “second” hand was occasionally put upon the escape wheel as a matter of curiosity, or as a going indicator. The circle was divided corresponding to the teeth of the escape wheel, but had no meaning. There was no occasion for a minute hand and the divisions of the hour were simply known as the half-hour, which half-hour was approximatively the value of our hour. Sometimes the spaces between the hours were divided into four or eight equal parts.
The changeover to brass has been placed in the early part of the 19th century solely on one unsupported statement that metal turning was not known in Japan before 1830. This is open to doubt. The potters’ wheel was certainly known in Japan, simple turning between centres had been used in the East for a long time and the Japanese had managed to produce circular arbors for their later steel clocks. Also the Chinese, with whom diplomatic relations were resumed in 1600, were well versed in the art of metal spinning. It is only simple turning that we have to consider; there is nothing to be found which could not be turned out by almost unskilled labour with a chisel, a gouge and quite primitive turns.
An alternative date when these developments could have occurred was from 1680-1709, under an enlightened Shogun, the arts were encouraged and the mercantile classes from being a despised minority, gradually became a power to be reckoned with. The Mitsui and Sumitomo families were already flourishing in this period and thus with the rise of a fairly prosperous middle class there was an increase in the number of possible customers. Also the import of foreign books was permitted.
Reports on Wadokei Construction
As dials, ornamental pillars, and similar parts could not be made solely by hand, it is evident that an instrument such as a lathe was used.
The figure illustrated JINRIN KUNMO ZUI published in 1690 shows a tinsmith at work with a lathe. In 1851, Hisashige Tanaka (of Mannen Dokei fame) advertised that for his jimei-sho: “The body of the clock is made by lathe (senban), a device that I invented.” Hisashige was reputed at that time to have been the inventor of the lathe and also to have invented a lathe to turn an ellipse. Designs of various clocks were exhibited in shops, and they were made in Nagasaki, Kyoto, Osaka, Yedo, Sendai, etc. ; but how far back the work of the clocksmith, as he was called, became a recognized craft does not appear; and the absence of signature and domicile leaves the matter in doubt.