Before the Meiji Period (1868–1912), Japan used a time schedule that was far more complicated than what we know today. Day and night were each partitioned into six equal parts called koku, but because sunrise and sunset times vary depending on the season, the length of the koku also changed from day to day. The traditional Japanese clock called wadokei was developed to adapt to this “temporal hour system,” a time concept that followed the sun. What sort of mechanical engineering swayed the evolution of clockwork away from the Western “fixed hour system” that ticks the time equally all day and all night? To find out, we spoke with the only wadokei maker in Japan, Takuro Naluse of NALUSE TOKEI Co., Ltd.
Japan’s Engineering Industry was Founded on “Amusement,” Not the Pursuit of Accuracy
With almost no reliable literature on traditional Japanese clocks, the origin of wadokei is not clear. According to the "Owari-shi" (a periodical from the Owari territory) compiled in 1832, “a blacksmith named Sukezaemon Tsuda repaired a clock that had been a gift to Tokugawa Ieyasu from Korea, and then used it as a model to create a new clock, which he offered to Ieyasu.” This is known to be the first mechanical clock made by a Japanese. Tsuda’s descendants remained in Owari and earned a great reputation serving the Owari Tokugawa Family as clockmakers for generations. “Nagoya’s thriving engineering industry today has its roots in this history,” says Mr. Naluse, whose home is also Nagoya.
Later, clock-making craftsmen, pioneered by Tsuda, remodeled imported“fixed hour” clocks to suit the Japanese “temporal hour system” that tells time differently depending on the season. The problem was that these clocks were handmade by craftsmen and as such, were quite expensive. Only a member of the shogunate, a feudal lord, or a wealthy merchant could afford one. Particularly elaborate clocks with delicate craftsmanship known as Daimyo (feudal lord) clocks were often owned to show authority. Once the technology popularized towards the end of the Edo Period, the clocks became available to wealthy townspeople. Again, practicality did not seem to be an issue. When the sun rose, people went to the fields. When it went down, they returned to their homes. In those days, the center of Japanese life was farming. They had no need to know the time anyway.
So then why did the traditional Japanese clocks exist? Mr. Naluse says, “They invested high technology into something they didn’t need. It was obviously amusement.” Almost excessive detail to the gear, decorative grace, the stately pedestal; the wadokei made its own evolution as a status symbol from start to finish, or an exclusive collector’s item for the enjoyment of mechanical engineering. It is interesting that the focus of technology is fundamentally different from the Western clock that insists on accurate time measurement.
The Temporal Hour System is a Healthy and Natural Time System Based on the Movement of the Sun
In order to understand the traditional Japanese clock wadokei, one must first understand the “temporal hour system,” which was the concept of time during the Edo Period (1603–1868). The method that divides the entire day into equal parts is called the fixed hour system. Commonly throughout the world today, our day is divided into 24 equal parts. Conversely, the temporal hour system separates daytime from nighttime and partitions those into six equal parts each. The most noticeable feature is that since day and night are different lengths depending on the season, this changes the length of the divided units of time. For people who are used to the fixed hour system, to have to depend on the sun to tell what time it is would likely be very inconvenient. In an agrarian society however, it is actually quite convenient. In Mr. Naluse’s words, “The temporal hour system based on the movement of the sun was a healthy and natural time system.”