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.
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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.
[url=http://lh4.ggpht.com/_EWDt_J4i-Q4/S77Jza2IS0I/AAAAAAAAD6c/znaYCYiXwoQ/Heuer1916.jpg][img]http://lh4.ggpht.com/_EWDt_J4i-Q4/S77Jza2IS0I/AAAAAAAAD6c/znaYCYiXwoQ/Heuer1916.jpg
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.
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[url=http://lh4.ggpht.com/_EWDt_J4i-Q4/S77J0t5jTEI/AAAAAAAAD6s/LCDdjj6N_hU/IMG_4404.JPG][img][/url]
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[url=http://lh4.ggpht.com/_EWDt_J4i-Q4/S77J1qPbHJI/AAAAAAAAD60/EtX3JBabXI0/IMG_4409.JPG][img][/url]
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”.
[url=http://lh4.ggpht.com/_EWDt_J4i-Q4/S77J1zQCfrI/AAAAAAAAD64/nxblfjKHKqk/IMG_4417.JPG][img][/url]
[url=http://lh5.ggpht.com/_EWDt_J4i-Q4/S77J2A_y2mI/AAAAAAAAD68/VNVz4eHmbtk/IMG_4418.JPG][img][/url]
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?
[url=http://lh4.ggpht.com/_EWDt_J4i-Q4/S77J2hpP9aI/AAAAAAAAD7A/QqPoyjphBwU/IMG_4423.JPG][img][/url]
[url=http://lh5.ggpht.com/_EWDt_J4i-Q4/S77J29MvLFI/AAAAAAAAD7E/BJkqm31w_sA/IMG_4424a.JPG][img][/url]
Inside the caseback are the following inscriptions:
[b]SKS[/b] ([i]Seikosha[/i])
[b]FINE NICKEL[/b]
[b]S76192[/b]
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.
[url=http://lh3.ggpht.com/_EWDt_J4i-Q4/S77J3NuE_II/AAAAAAAAD7I/LJ0UjeG_B9E/IMG_4425.JPG][img][/url]
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. :)
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Mysterious Stopwatch Dial [...Part II...] ...(Large pics)
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An interesting piece. The beat rate is easily calculated from (20 beats per second) = 20 x 60 x 60 = 72,000 bph. A rate this high requires special materials, oils and ways of overcoming stresses not found in lower beat movements, which may account for the unusual routing of the hairspring where it attaches to the stud carrier. (Unless it's been assembled incorrectly, which may be why it's not running.)
I doubt the stopwatch's intended use is for equestrian polo, as someone mentioned previously. True, each chukka lasts a maximum of 7.5 minutes, but the clock is stopped every time the umpire blows his whistle. Since your is a single-button stopwatch I'm guessing it resets to zero after being stopped, thus rendering it unable to cumulatively time a chukka. The same goes for water polo.
The fact it records time to 0.05 sec indicates it's intended more for timing single competitive events such as an athletics or horse race, which can be decided by such a small amount. It could certainly be used for horse training, so that's what I'm putting my money on.
Oh, and that engine-turned finish is called perlage, not perlee!
I doubt the stopwatch's intended use is for equestrian polo, as someone mentioned previously. True, each chukka lasts a maximum of 7.5 minutes, but the clock is stopped every time the umpire blows his whistle. Since your is a single-button stopwatch I'm guessing it resets to zero after being stopped, thus rendering it unable to cumulatively time a chukka. The same goes for water polo.
The fact it records time to 0.05 sec indicates it's intended more for timing single competitive events such as an athletics or horse race, which can be decided by such a small amount. It could certainly be used for horse training, so that's what I'm putting my money on.
Oh, and that engine-turned finish is called perlage, not perlee!
gary6213 said:
Thanks, Gary. As for application, I'm still researching the uses of the Heuer timers in those days, and I'm guessing whatever those were used for, mine was Seikosha's alternative. Also thinking that this particular stopwatch may have been only available in Japan, and that might narrow down the application. I know that, in the West, we see a stopwatch and tend to associate it with sports (and we can therefore invest in expensive gear, because there's money to be made there), but early 20th Century Japan may have been a different place altogether.
...I'm still reading up on it.Thank you, Sir Les. That's very useful to know, as I do not know much about the positioning of the hairspring. I'll try and find more information on oiling and material. The colour of the ratchet and crown wheels, as well as the screws, is quite peculiar and looks bluish gun-metal (whereas anodized would look grayish gun-metal). At the moment, it doesn't wind, but I'll certainly have my watchmaker to look at it, as I certainly don't want to break anything.Sir said:
72,000 is what I worked it out to be as well, but wondering how Heuer achieved 0.01 resolution at only 180,000 bph, when 360,000 bph should have been needed. Unless my source is incorrect--will double check on this.
Oops... you are right. I was looking at through references in FrenchSir said:Oh, and that engine-turned finish is called perlage, not perlee!
...it is indeed perlage in English... thank you 1 - 5 of 5 Posts
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