NOTE:  The description of the mannen-dokei in this web strand has intentionally been kept brief as numerous other dedicated books and web strands, including those of Toshiba Corporation, are able to give far better justice to this outstanding clock.

Appearance:      Hexagonal table clock with six dials and glass domed planetarium above.

Period:               1851.

Escapement:     Various.

Power Source:   2 x Brass Spring – year going.

Construction:   On the top of the clock there is an orrery in which the sun and moon automatically orbit over a map of Japan.  In the base there are four mainsprings; their great power controlled by fusees.  For exterior decoration, the techniques of inlay, cloisonné and chasing are skilfully used.

The clock consists of more than 1,000 parts and it is said that the clockmaker Tanaka Hisashige made all the parts himself using simple tools and a lathe that he made for the pupose. It took more than three years for him to finish the assembly.  The clock incorporates the following features – many unique:

• Large hexagonal table clock, 63 centimetres in height, that runs for six months on one winding of the mainsprings
• There are six dials and indicators around the hexagonal case:
  • Western time dial
  • Japanese wa-dokei temporal hour dial
  • Twenty-four seasons of the Japanese ‘peasants calendar’
  • Day of the week indication (shichi yo ho)
  • Date by the sexagesimal cycle
  • The days for one month of the Japanese lunar calendar
• These dials are synchronised and move continuously

As the news spread, everyone was astonished by the clock’s excellence but no buyer appeared.  Some of the ‘daimyos’ wanted it, but due to financial deficiencies near the end of the Feudal period they could not purchase it.  Therefore, it remained in the possession of Tanaka’s family.

In his Tanaka Omi Daijo by Seisuke Tanaka, the young author wrote the following:

“It is reported that Izumomo-kami Matsudaira, the lord of Matsui Castle, Unshu, liked a variety of clocks and erected two buildings to house them.  One time while returning from Edo he stopped at the officially appointed inn at Fushimi.  There he heard about the Mannen Jimei-sho and he desired to see it.  At once it was brought to Fushimi.  Seeing it, Lord Matsudaira ordered its purchase at once, but his attendants informed him the cost would be at least one thousand ‘ryo’, and they advised him to postpone the purchase.

Therefore the order was retracted and an indemnity awarded as compensation.”

The ‘mannen jimei-sho’ remained the property of the family, and it can be said that it eventually settled at the place most closely associated with it.

The clock was listed in the Mechanical Engineering Heritage as item No. 22 in 2007 and is now located in the National Museum of Nature and Science in Tokyo.  A replica can also be seen in the Toshiba Museum, Tokyo.