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  1. #1
    Robert T. Raucher
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    Default Glass "Bullseye" PW Crystals (By: Robert T. Raucher)

    Hello...I am curious if anyone might know when Glass "Bullseye" Crystals for Pocketwatches was phased in and when they were phased out? Thanks. Robert Chico, Calif.

  2. #2
    Robert T. Raucher
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    Default Glass "Bullseye" PW Crystals

    Hello...I am curious if anyone might know when Glass "Bullseye" Crystals for Pocketwatches was phased in and when they were phased out? Thanks. Robert Chico, Calif.

  3. #3
    Steve Maddox
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    Default Glass "Bullseye" PW Crystals (By: Robert T. Raucher)

    Robert,

    I believe these were used primarily in the first half of the 19th century, but perhaps someone else can offer more specific information.

    As a side note, why were these ever made? Was it just for "style," or was there some practical purpose?

    ------------------
    Steve Maddox
    President, NAWCC Chapter #62
    North Little Rock, Arkansas

  4. #4
    Registered User Jerry Treiman's Avatar
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    Default Glass "Bullseye" PW Crystals (By: Robert T. Raucher)

    I believe the original bullseye crystals were cut from blown glass. I expect a dop stick (is that the right term) was still attached to the center of the crystal and used for turning an even perimeter. When this was removed the spot in the middle would have been ground and polished flat.
    Jerry Treiman, NAWCC member since 1971
    Charter member of Pocket Horology Chapter 174

  5. #5
    Technical Admin Tom McIntyre's Avatar
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    Default Glass "Bullseye" PW Crystals (By: Robert T. Raucher)

    Hank & Marge Farrer do a talk on this subject at regionals and other events. Perhaps I can get one of them to respond here.


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  6. #6
    Marge
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    Default Glass "Bullseye" PW Crystals (By: Robert T. Raucher)

    According to the research we did in preparation for our talk, watch glasses, commonly called "watch ctystals", began to be made shortly after 1600 A.D. The first watch glasses were made by blowing a glass sphere. These crystals were all high domed.

    There is currently some controversy as to whether they had a "bullseye"(thick flat center)or not. Most written references indicate the first watch glasses had a "bullseye" for the reasons Jerry indicated in his post. However, some prominent present day British horologists think not. Since all of the people who were there are long gone, we will never know for sure!

    About 1800, watch case styles changed from pair-cases to single cases that looked like pair-cases. This was an intermediate step to the conventional double backed pocket watch case of the 19th century. Also, thanks to improvements in manufacturing methods, the glasses fitted to the cases changed from the high domed glass to a thinner less curved glass.

    If anybody has a written reference pertaining to the "bullseye or no "bullseye" theories, we would appreciate hearing from you.

    Marge Farrer



    [This message has been edited by Marge (edited 03-07-2002).]

  7. #7
    Robert T. Raucher
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    Default Glass "Bullseye" PW Crystals (By: Robert T. Raucher)

    Thanks for all the replies. I am not looking for how they were made...but at a minimum when the item was phased out of Pocketwatch production, in terms of approximate year. Robert.

  8. #8
    Marge
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    Default Glass "Bullseye" PW Crystals (By: Robert T. Raucher)

    Robert -

    Around 1800. But, like other changes, some makers probably made the change years earlier than other makers.

    Marge

  9. #9
    Barry G
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    Default Glass "Bullseye" PW Crystals (By: Robert T. Raucher)

    Well, I'm not sure you can really give a firm cutoff date for this or any other watch realted technology that you have been asking about in various threads. Yes, by 1800 the technology existed to produce better quality crystals that didn't have a bullseye "flaw", but as far as I am aware many watchmakers continued to use the bullseye crystals for many years thereafter, especially on lower grade watches. It's not like they would have just thrown them all out the minute better crystals became available, and it also takes time for new innovations to propigate and become accepted and popular.

    The same holds true for just about any innovation, whether it be stem winding vs. key winding, going barrel vs. fusee, pair case vs. hunter case, what have you. It's easy [well, relatively] to point to when each innovation was first invented and/or introduced, and it's even possible in most cases to find out when it became widespread. But I sincerely doubt there was ever a firm cutoff point when everybody suddenly adopted a new practice overnight and threw out all the old materials and ways of doing things.

    Regards,

    Barry

    ------------------
    My Online Pocket Watch Collection

  10. #10
    Oliver Mundy
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    Default Glass "Bullseye" PW Crystals (By: Robert T. Raucher)

    I have the impresssion that the golden age of the bullseye was from about 1780 to 1820. They do not seem to go back to the earliest days of watchmaking. I have two watches dating from 1763 (approx. - this one is not hallmarked) and 1775, and both have plain high-domed glasses without bullseyes; the glass seems to have been produced by blowing and is quite thin - too thin, probably, to allow the centre to be ground back even if this had been desired. Bullseye glasses are generally thicker; I suspect, although I have no documentation, that their introduction coincided with changes in the method of manufacture which allowed glasses to be made thicker and therefore more durable than the hand-blowing process would have permitted.

    Of course there is no guarantee that the pressent glass on an 18th-century watch is original; but presumably such items as the earliest chronometers by Harrison, Kendal and Arnold have been secure against later interference, and it is noticeable that none of these, as illustrated in the reference-books, have bullseyes.

    I am not sure about the theory that the ground-down central section was a device to remove pontil-marks or other flaws. It may have been based on the idea that the centre of the glass, being the most prominent point, was therefore the most vulnerable to scratches and chips; but I suspect it was largely a matter of fashion, giving the watch some of the appearance of a scientific instrument with an ?optically-ground? lens.

    Bullseye glasses certainly lasted some years into the 19th century. My Joseph Johnson watch (1820-21) has one. As Marge has said, they tended to die out concurrently with the pair-case; and yet I have occasionally seen them on Swiss watches as late as the 1870s.

    ------------------
    The Watch Cabinet

  11. #11

    Default Glass "Bullseye" PW Crystals (By: Robert T. Raucher)

    Bullseye like crystals were available in the early 20th century. These had a little round bullseye at the center but they were not high dome crystals like the earlier "true" bullseye. These later ones were called "Patent Geneva" by at least one material house.

    hope this helps,

    Greg

  12. #12
    Robert T. Raucher
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    Default Glass "Bullseye" PW Crystals (By: Robert T. Raucher)

    Hello...thanks to all who answered my question of this list. Very imformative. Robert

  13. #13
    Steve Maddox
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    Default Glass "Bullseye" PW Crystals (By: Robert T. Raucher)

    Robert,

    I agree with Oliver and others, who say that early watches had plain high domed crystals, and that the "bull's eye" type came into style and went out again a few decades later. Oliver may be correct in the timeframe he suggests (1780-1820), but I think it was a bit later than that. I think the prime popularity of "bull's eye" crystals began about 1790-1800, and ended about a half century later. Furthermore, like "pair cases," I think "bull's eye" crystals were much more popular in Britain, than they ever were anywhere else.

    Regardless of what some "authorities" claim, I don't think the "bull's eye" had anything to do with assisting in the manufacturing process; I think it was merely for style, and nothing else. Some relatively modern references indicate that the "bull's eye" spot was ground to facilitate mounting on mandrels to grind the edges round, but that idea fails to consider that rather than grinding each and every crystal with a flat spot, it would have been much easier and more efficient to use mandrels that were slightly concave, and fit the natural curve of the glass.

    I've looked through my "library" quite a bit for an authoritative source for this information, and I can't find it again at the moment, but I had an occasion to research this subject fairly extensively a few years ago, and I was eventually satisfied I'd found the correct information. I have a 1780s French "pump-type" repeater, that's unusually large, and I was having a devil of a time finding a bull's eye crystal for it. At length, I discovered that watches of that era weren't necessarily intended to have "bull's eye" crystals, and the plain high-domed crystal I was trying to replace was indeed appropriate. "Bull's eye" crystals may have been available at the time my repeater was produced, but they actually came into vogue a bit later.

    In any event, you may be certain that "bull's eye" type crystals enjoyed relatively limited and short-lived popularity, and that they're not appropriate for very significant percentage of watches that survive today.

    SM

  14. #14

    Default Glass "Bullseye" PW Crystals (By: Robert T. Raucher)

    De Carle shows two types of crystals with circles in the center. the high dome ones he calls "Bull's Eye" and the low dome ones he calls "Double Lunette, Cut Top".

    FWIW.

    Greg

  15. #15
    Oliver Mundy
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    Default Glass "Bullseye" PW Crystals (By: Robert T. Raucher)

    As a pendant to Steve's comments about the purpose of the bullseye, I have noticed that the ground section is frequently off-centre ? which could scarcely be the case if it were intended as a guide during the manufacturing process.

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