Unlike Europeans who allowed the clock to master them and change their lifestyle, the Japanese never considered this. Instead, the Japanese changed the clock to suit their traditions. The early gifted European clocks were developed to show unequal hours.
(Note: Europe through to the early 1400’s also used temporal time – i.e. throughout the Egyptian, Greek and Roman periods, as well as medieval periods. It was only the introduction of employer / employee working arrangements which could operate consistently throughout the year that encouraged the adoption of the 24 hour system throughout Euriope. The Italians retained temporal time through to Napolean times – and even thereafter.)
Japanese clocks were developed with unique shapes and mechanisms, leading to the creation of temporal time clocks (striking) and timepieces (non-striking); the products of ingenious technology and creativity. They had various names, including tokei, jimie-sho, jimie-ban, jin-shin-gi, however today they are collectively known as wadokei (“wa” being the Japanese particle, and “dokei” being clock).
Until the Meiji era no clocks were made by machinery. Early Japanese capabilities in metalworking are renowned. Generally, these capabilities are most commonly referenced in the production of either samurai swords or works of art. However, the craftsmanship was equally applicable to wadokei. Virtually all work was carried out by handworking. However, it is recorded that the European engineering lathe was introduced to Japan in 1830.
With the exception of a very few dated and/or named clocks, it is not possible to do more than describe Japanese clocks as early, middle or late in style and character. Generally these styles are aligned with ‘early’ being 17th century; ‘middle’ 18th century and ‘late’ 19th century. However, even these designations can only be applied broadly since nearly all clocks were individually made across the length and breadth of Japan and its islands (extending 1200 miles) as well as being made in the few major port cities which became cosmopolitan centres of the nation.
These major ports were filters for the latest exports of the western world and were adopted or modified as best suited to the Japanese way of life. However, the process of assimilation was slow and the earliest types of clocks were still being made in the interior of Japan long after they had been superseded by new designs in the cultural centres.
As was the custom in Europe, some priests were skilled in clockmaking. For a period of about 30 years, ending in 1612, not only did they make clocks, but they also taught their trade to Japanese blacksmiths in Kyushu and Kyoto. These blacksmiths incorporated Japan’s ancient system of timekeeping into new mechanical clocks, giving rise to the first wadokei clocks which began to appear from around 1612. They were generally known as ‘Daimyo clocks’ as only the Daimyo, or nobles, could afford to buy them and employ a permanent clock maker or ‘time doctor’ to make the necessary daily and seasonal adjustments. Since the hours of daylight and dark altered throughout the year, this meant a constant alteration of the rate of the clock. Clocks were not imported as trade items, but were gifted by European traders as favours for decorative and elitism purposes.
The Japanese were particularly accomplished at working metals and this made them ideal clockmakers. The first recorded clockmaker was a skilled blacksmith by the name of Tsuda Sukezaemon Masayuki, now known as the father of Japanese clockmaking. He was the founder of a flourishing clock industry in Nagasaki, which spread to Nagoya and Kyoto.
Initially, clock craftsmen in Japan did not make clocks for the purpose of improving time keeping accuracy. There were privileged clock craftsmen who were employed by the feudal lord, and there were some individual clock craftsmen. The clock was expensive in the Edo period, and the general citizen could not afford it. Equally, the general citizen did not need accurate time in social life, because they knew the time by the sound of the town bell-tower or the temple.
From an article in the Nihon Seikoo Shi of 1607:
“By order of the Shogun a Japanese missionary stayed at Edo castle as a keeper, Kanshu-nin, of a jimei-sho made previously at Nagasaki….”
An encyclopaedia Wakan Sansai Zue, published in 1715 by Gozasso, describes Japanese clocks as follows:
“Jimei-sho are generally called tokei.”
“The missionary, Matteo Ricci, has a jimei-sho. Each time that it reaches a toki it immediately rings. Even while passing, the time is shown correctly. It is wonderful.
Presently, astronomers can merely guess propitious times and cannot predict correctly. To measure time in daylight, there is the sundial; at night, the water clock must be relied upon but it is not very accurate. Moreover, rural villages do not even have water clocks. Therefore, regarding human destiny, astronomy can rarely be correct.
The Andokei, another name for the Kei-shaku, has a base made of wood 2.424 meters, or eight shaku, in length. In sunlight it indicates the time and also the difference between the summer and the winter solstices. This instrument is indispensable for astronomers.”
Water clocks have vessels filled with water that while slowly flowing shows the time. The principle is ingenious. Emperor Tenji made the first one in Japan, in A.D. 671, the tenth year of Tenji (662-671).
The time was struck on a bell. However, the jimei-sho, which have appeared recently, are superior to water clocks and too are called tokei.
The yagura-dokei is a jimei-sho placed upon a truncated, pyramidal stand, and thus, as it rings automatically, it resembles a belfry.
Clockwatches, or futokoro-dokei, were brought to Japan first by the Dutch. These are small and can be carried in one’s pocket.
There are hanging clocks that can be suspended on pillars. These have two pairs of weights to drive the time and strike trains. When winding, the large weights rise and the small weights descend. Inside, wheels with many teeth revolve.”
This encyclopaedia describes most kinds of rokoku and jimei-sho and explains that jimei-sho were more accurate and convenient than sundials or water clocks. Inasmuch as a description of springs is also written, mainsprings are considered to have already been known.
Hanzo Hosakawa published his infamous three volume set of books Karakuri Zui giving technical data about automated toys and clocks. Volume two provides detailed plans for constructing an 18th century Japanese clock. This provided a major reference for boosting wadokei construction.
This period can be termed the Golden Age of wadokei construction, where the majority of traditional lantern style clocks produced were of exceptional quality and decoration.
This period saw the rapid development of shaku-dokei, makura-dokei and other more complex designs, some with mainspring power sources and some with pendulums.
Throughout the development of wadokei, one of the key drivers for improvement was the reduction of the frequency and skills in making temporal time adjustments.
Early-period single foliot lantern style clocks required daily adjustment by capable clock-doctors at dawn and dusk to compensate for day/night hours and the seasons. Middle-period double foliot lantern style clocks and shaku-dokei only required adjustment by capable clock-doctors every 14 days to account for the seasons. Then by the later-period, shaku-dokei clocks and a few lantern style clocks were capable of adjustment by unskilled operators and some even fully automated the adjustments throughout the year.