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Information on 19.73 and 19.73N "Double Face" Chronograph

  1. Seiji Oct 1, 2017

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    [​IMG][​IMG]
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    I've tracked down 5 of them. One theory seems to be that they are Pilot watches. Other is that they are military. Two with 4 digit numbers are in Mexico. One is in Monaco. Any solid information? The Roman numeral watches are more scares but are documented by Longines.

    Update: Roman number versions were produced. At this time period any customization was available so there are a variety of possibilities. I currently do not think these watches were used for aviation. They were most likely used for sports like racing horses or automobiles.
     
    Edited Jan 4, 2023
  2. Foo2rama Keeps his worms in a ball instead of a can. Oct 2, 2017

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    Could have been for factory managers.
     
  3. SeanO Oct 2, 2017

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    You'd need to see the factory brochures for the year in question. The Roman numerals may well have been an option at the time of issue.

    or it may have been a "special order" for a good client. the problem with pocket watches is that there ARE so many variations of dials as standard from the factory.

    I reckon it's more a science instrument rather than a flight instrument.
     
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  4. Skrotis Oct 2, 2017

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  5. OMTOM Oct 2, 2017

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    Thanks Patrik - with Omega I'd be in there but not with Longines!
    Tom
     
  6. Seiji Oct 3, 2017

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    This came from Longines Museum.
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  7. Syrte MWR Tech Support Dept Oct 4, 2017

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    That multicolor dial is wild!
     
  8. vvvaaa Dec 26, 2017

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    Hello everybody.

    I think some posts of mine here may have been deleted – for whatever reason, so I'll sum up what I said. Forum-owner, pls pm me if I disregard/ed any rule, thank you.

    This double photo – and watch – belong to me, have been in family hands since the twenties. So I can confirm this are the original hands, so-to-speak ;-) and dials. This model was made between the late 19th ct and the 1940s, I suppose (19.73 and after 1909 19.73N).The pseudo-art-nouveau hands in the other photo are not authentic. And I too have tracked other examples, none with roman numerals. The minute counter is colour-coded for speed measurement – it's a tachometer, but whatever its primary practical use was, imho it seems too fragile to have had any field-usage. If anyone is interested, I can add photos after a revision. On condition that anyone who borrows them mentions the source, of course :)

    I'll also repeat that I'm trying to have it repaired/restored, which has proved quite an adventure. f.i. I'm looking for a balance wheel or a donor 19.73N movement etc. I'd also be grateful for any info or help with repair. I'd like to see the s.c. “Furnitürentafel”, i.e. the original parts-table and specifications.
     
  9. DirtyDozen12 Thanks, mystery donor! Dec 26, 2017

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    Think it is a tachymeter scale rather than a tachometer scale.
     
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  10. vvvaaa Dec 26, 2017

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    Thank you for the correction. In British English at least “tachometer” seems to be correct also but perhaps the two have a different function. So please go into detail if you wish.

    A second correction: I made a confusion. It is because Seiji also posted in another forum with the same material that I mistakenly thought I'd replied here but in fact I replied there. Please excuse my error (and allow me to correct it if the software allows)…
     
    Edited Jan 18, 2019
  11. Foo2rama Keeps his worms in a ball instead of a can. Dec 26, 2017

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    Tachymeters have lots of use actually not in the field. Pre 1900 and through today they can be used to time production times in factories andrea yield production per hour. In fact I believe that was the original intended use.
     
  12. vvvaaa Dec 26, 2017

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    The tachymeter-dial (FireFox autocorrects to “o”…) is marked Base 1000 mètres and in the dial-centre Base 100 mètres. F.i., 15" into the 1st (red) min. = 240 kmh. Was there any thing short of a strong wind that travelled 240 kmh in 1929? 1min 15" (360° wraparound) is 48 kmh. I do guess they would count more than meter-fabrication ;-) and it can measure any time-number relation, but my maths courses are many wraparounds back.
     
  13. vvvaaa Dec 26, 2017

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    Haha, I just saw in Seiji's photo of the display at the Longines Museum above, you have both versions (o/y) în FR and EN. Actually it seems it comes from GR tachos (read takos) for speed, so somehow (etymologically/linguistically) both are right, but is there a technical distinction between the two? :)
     
  14. Foo2rama Keeps his worms in a ball instead of a can. Dec 26, 2017

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    Pretty easy stand over worker putting an item together. Start at start of build end at start of next build. That yields items per hour.

    Sit at end of line time 10 items completing. Take reading times 10 and you get production per hour.

    This used to be taught in business school textbooks. There are old advertisements for tachy stop watches built for this purpose.

    Hence the expanded scales going to 20 and lower.
     
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  15. vvvaaa Dec 27, 2017

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    Huh! A capitalist watch… As he bought it in late 1930, it's owner was a goldsmith in his early twenties… (first image above). For the second image pair, the hands seem to have come from a 1905(?) Longines modelPurchases made through these links may earn this site a commission from the eBay Partner Network. For the Roman numerals I found this 1913 ad (see below). The top one is NOT the tacho side of the one below, just a contemporary model.

    Foo2rama, please, do you have sth like an original users' leaflet or instructions?

    Looking with a loupe at the dial, I found a matted area. Were these enamel dials lacquered or did they shine “naturally”?
     
    1913small.JPG
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  16. vvvaaa Dec 30, 2017

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    longines doubleface 19.73N.jpg Thank you Seiji. See image – your #1 image above :) after cleaning. The area at 6 o' was badly retouched. Colours faded, the enamel is also matted. I wondered whether they may have used some solvent on an original vernis. The damage you see is typical for a fall: it's around one of the feet ot the dial. Otherwise both dials are not cracked. I wondered what can be done… Mechanical polish? Are there special retouching paints?

    Everybody: thank you and a happy new year!
    :)
     
  17. vvvaaa Dec 31, 2017

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    Wow, they seem to be doing quite a job. I asked for a quotation… And also asked what the procedure and risk would be.

    Thank you!
     
  18. vvvaaa Dec 31, 2017

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    … and the very swift reply was they cannot (“too complex”) :)
     
  19. vvvaaa Jan 19, 2018

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    A better scan of that ad Longines DF.jpg bbhgeetx4344qq5r
     
  20. vvvaaa Jan 21, 2018

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    Seiji, interesting… I had a short email exchange with mme Lachat about one year ago, in the early stages of the adventures with my double face. She tried to help, but the Longines watchmakers said the watch is beyond repair, which, after having had it cleaned, seems a bit exaggerated (except I cannot find a balance). I thought of trying againm ok.

    I'd like to see the book/ those pages – can I please have the publication details?