Daini-Seiko-sha, V-031

A very rare Imperial Japanese Navy Chronometer manufactured at the beginning of WWII that still retains the original winding key, case key and felt lined carrying case.

The three-tiered case is made from a Japanese hardwood and is fitted with brass handles to the sides, has traditionally shaped brass escutcheons, chrome plated hinges and a silvered engraved plaque with ‘V-031’ and two stamps indicating naval service.

The engraved matt silvered dial has Roman numerals for the hours, Arabic numbers for the subsidiary second’s dial and winding indicator, blued steel hands, Japanese characters and the serial number, V-031, in red. It is set behind a screwed bezel with a knurled outside edge, silver reflecting ring and beveled glass.

The finely finished gilt chain-fusee 56-hour movement has decorative tool work to the plates, carries the Daini-Seiko-sha trade mark stamp, is numbered ‘V-031’, has finely cut and finished wheelwork, is wound out the bottom and has shaped pillars affixed by screws. The bimetallic balance wheel has adjustable cylindrical weights for temperature compensation, timing screws, an elinvar helical balance spring and is set in jewels top and bottom. The original detent and escape wheel are set adjacent to break circuit work used for rating.  The whole is housed in a gimballed brass tub that is locked by a screwed swing latch.

This piece still retains the original ratcheted winding key, case key and felt-lined outside box.

In 1938, during a time of great international turmoil, the Japanese naval command decided they needed a dependable supply of domestically produced marine chronometers. The Daini-Seiko-sha company began production in 1942 after enlisting some leading engineers and doing extensive research. The chronometers they produced were near perfect copies of those produced by Ulysse Nardin with all the components produced entirely in Japan. They were, in fact, so good they often produced a daily deviation rate of .1 seconds which far exceeded the naval standard.

Less than 600 examples where originally produced with very few surviving the near total destruction of the Japanese Navy.

For additional information see:

Haruyama, T., The First Japanese Precision Timepieces: A Brief History of the Seiko Marine Chronometer, NAWCC Bulletin, October 2000, pp 581-586.

http://www.knirim.de/haruyama.htm

http://www.antiquorum.com/catalog/lots/lot-75-265?browse_all=1&page=3&q=japanese+chronometer#