What is a Wadokei (Traditional Japanese Clock)?
The distinctive mechanical clock used in traditional Japanese timepieces was created in Japan during the Edo era. Based on a mechanical clock imported from Europe, this traditional Japanese clock was created in line with the "seasonal time system," the time system utilized in Japan. The duration of a day is divided into equal pieces, or hours, under our present "fixed time system," which governs how time is kept. Up to the early Meiji period (1868–1912), Japan employed a "seasonal time system" that split a day into day and night, then divided each into six segments. A seasonal time clock had to be regularly adjusted since the duration of the day varies from season to season. This was necessary to maintain alignment with the daylight hours throughout the whole year.
In the entire globe, there are very few clocks designed to keep time for antiquated time systems like Japan's seasonal time system. Traditional Japanese clocks have been made and used for more than 200 years.
The traditional Japanese clock's forms were also modified to fit the way of living in Japan at the time. There were pillbox pocket watches, pillar clocks, and lantern clocks all made. Many were excellent pieces of art that were also well-liked elsewhere.
The earliest known mechanical clock was a self-ringing bell that was one of the presents given to Yoshitaka Ouchi, the feudal ruler of Suo (the modern Yamaguchi prefecture), by the Spanish missionary Francisco de Xavier. In 1551, a Spaniard traveled to Japan to ask for permission to spread Christianity. The actual clock has been lost to history. The oldest clock still in use in Japan is a spring-driven table clock that the governor of Spanish Mexico gave to Ieyasu Tokugawa, the founder of the Edo government, in 1612. It is presently kept as a treasure at Shizuoka Prefecture's Kunozan Toshogu temple.
After 1873, when the fixed time system took the place of the seasonal time system, the traditional Japanese clock gradually vanished.
What happened when Christian missionaries and dealers brought mechanical clocks into Japan?
In 1551, Francis Xavier sent a mechanical clock to the daimyo of Suo Province in Yamaguchi Prefecture. A spring-driven clock was given to Ieyasu Tokugawa, the Shogun, in 1612.
Japanese blacksmiths began producing clocks and were referred to as tokeishi (時計師) or clock manufacturers. The majority of Japanese clocks were designed to resemble lanterns called Yagura-dokei or towers named Dai-dokei.
Instead of putting Japan on a fixed mechanical time system, these clock makers devised clever ways to modify mechanical clocks to account for the irregular time in Japan. The clock mechanism may be changed for non-constant time in one of two ways: either by shifting the weights to modify the pace of the clock, or by moving the hour markings on the dial.
If you're curious in the mechanics, you may see how they operated on this page of the Japan Clock & Watch Association's website. Two sets of weights are located at the top of this lantern clock in the Matsumoto Timepiece Museum, and they may be adjusted individually for day and night.
