A couple of weeks ago, I posted on the old forum in relation to a Seikosha stopwatch with a mysterious dial. ( http://www.network54.com/Forum/78440/thread/1269731297/Mysterious+stopwatch+dial+--+Please+help!! ).Thank you to all who have contributed. I have since received the Seikosha, and am posing an update.
While I’m still unable to find another Seiko high-precision timer (the greatest resolution has so far been 1/10 sec), I did find a Swiss manufacture that did offer some. In fact, Heuer is famous for being the first to offer a 1/100 timer in 1916. Here’s a page from the catalog of the period.From the specifications that accompany, notice that these Heuer models complete1 revolution in 3 seconds, and a minute accumulator sub-dial up to 3 minutes.To achieve this, Heuer built their movement with a beat rate of 180,000 A/h.
The company later released the 1/50 time, the Semikrograph,with split-seconds functionality. Notice how the sweep centre hand in thismodel would complete its revolution in 6 seconds, and tallying the minutes upto 3 minutes (as in the 1/100 models).
(Image source: www.onthedash.com)
My apologies for the non-Japanese watch content, but the purpose is to arrive at the conclusion that the Seikosha we are examining is a high-precision timer, and, in line with Heuer’s, has the following spec.
1/20 sec recorder, 1 revolution in 15 sec, 0-7.5 minregister
Compared to Heuer’s 1/100 stopwatch, Seikosha cannot match its resolution, but makes up by offering timing over a longer duration. I havenot yet found information on the beat rate of this Seikosha, but am wondering whether the 1/20 resolution requires the movement to beat at 36,000-72,000 A/h. Perhaps someone who has more knowledge of horology can help me on this.
Here are more images. Stop watch hands are blue steel.
While pocket watches may be considered as both tool and jewelery, I’ve always thought that timers/stop watches are more [i]tool[/i] in nature, and would expect the overall design to be utilitarian as a result. I was very surprised, therefore, to find the level of finish and decoration on the movement of this Seikosha. The movement plate is decorated with stripes,similar to [i]Cotes de Geneve[/i], while the hinged case back is decorated [i]Perlee[/i]. Thequality of finish is as good as, if not better than, those I’ve seen on Seikosha Precision of the 1930s and 40s.
Inscribed on the movement plate are "SEIKOSHA” and “ADJUSTED”.
Beneath the balance is stamped "G7". Notice that the [i]G[/i] seems to have been machine stamped/pressed, while the [i]7[/i] look as though it was hammered in by hand. Would this imply that there are other Gs?
Inside the caseback are the following inscriptions:
I believe the Sxxxxx is the serial number (unique to each piece), rather than a reference/model number. This is from the fact that I have seen a WWII-era Japanese Army Seikosha stopwatch which has similar Sxxxxx number found stamped inside the case back, hand-written on the dial. This may have been for ease of identifying each piece when the Japanese Army issued the stopwatch to personnel.
This particular piece is currently not running, but seems tobe all complete. I may get my watchmaker to have a look at it, but to me, apiece like this is special regardless of whether or not it is operational.
I am, however, still seeking further information regarding the movement inside, and in particular, which specific pocket watch calibre, if any, it was based on. I’m also looking for anything relating to Seikosha’s early stopwatch.So, comments and help would be much appreciated.
Thank you. :)