Negus Sidereal, Break Circuit Chronometer

Discussion in 'Chronometers' started by Paul Regan, Jan 31, 2018.

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  1. Paul Regan

    Paul Regan Registered User

    Mar 4, 2003
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    I have been wanting one of these for some time and the opportunity availed itself last week. This is Negus Sidereal, Break Circuit chronometer No. 1769. It has a very storied history that, with minimal searching on Google, has turned up many occurrences starting in 1893 with the last I have found being 1918. I am certain there is a lot more to be found on this chronometer which served the U. S. Coast & Geodetic Survey. Within the USC&GS 1894 Annual report there is this quote, "Sidereal break circuit chronometer Negus 1769 breaks the even seconds and the fifty-ninth". I ran a brief test of the chronometer today and it still does the same while keeping sidereal time. The most striking adventure I have found that this chronometer participated in was the "failed" Ziegler Polar Expedition of 1903. Shortly after reaching the Franz Josef Archipelago their vessel, the America, sank after being crushed in sever ice. The members of the expedition were stranded on an island for two years before being rescued. It is amazing to me that I have in my hands this chronometer that survived that experience as well as I am sure many more. As received it is simply a movement/tub that is housed in an aluminum shipping container with a belt that is riveted to the shell. Judging from the wear on the bottom of the tub, I suspect it was used in this form for many years. I shall make an appropriate Rosewood box for it. Here are a few photos of this wonderful piece

    DSCN5959.JPG DSCN5973.JPG DSCN5969.JPG DSCN5965.JPG DSCN5953.JPG DSCN5957.JPG DSCN5954.JPG DSCN5955.JPG DSCN5978.JPG
     
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  2. Jim Haney

    Jim Haney Registered User
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    Sep 21, 2002
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    Paul,
    I am happy that you found this historical timepiece and thanks for sharing it.

    I am surprised that there is no engraving on the plates, was it made by contract and what year.

    I think I am seeing the circuit break under the balance between the 2 pillars??

    Great Piece !:D
     
  3. Paul Regan

    Paul Regan Registered User

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    Thanks Jim,
    I have never seen any engraving on Negus plates. The only engraving on this one is the serial number and JP (Joseph Preston, frame maker) on the dial plate.
    I would believe this chronometer would have been special ordered by the USC&GS.
    Yes, that is where the break circuit is. It appears to be insulated with Ivory. One of the electrical connections is grounded to the tub and the other is insulated with ivory also. All of it still functional.
     
  4. Jerry Freedman

    Jerry Freedman Registered User
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    Sep 16, 2000
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    Paul: Your USC&G related chronometer has made me write about one of mine . I have one that came with the initials USGS and # T222173 engraved
    on the shipping container and brass bowl. The container also has a label for C. G. Smith of Silver Springs, Maryland.

    It is a very old instrument dated to 1828 by Jonathan Betts of the Royal Observatory. It is a one day chronometer #124 by John Heron of Greenock , Scotland. Do you have any way of finding out when the USGS would have acquired this chronometer and what it may have used for?

    Jerry Freedman
     
  5. Paul Regan

    Paul Regan Registered User

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    Jerry, I have yet to find out if the USC&GS had their own Observatory. It's interesting that yours is also in a shipping container. It must have been the preferred way to carry these around. It also made setting up easy.
    I'll keep looking and update this thread if I find out more. This is why we collect these things!
    Paul
     
  6. Tom McIntyre

    Tom McIntyre Technical Admin
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    Chronometers were used in the national survey in confunction with the recording chronograph(s) invented by Bond. I would have thought the tub chronometers were part of that mix. I would look through the Bond records at Harvard Historical Instruments Collection.
     
  7. Paul Regan

    Paul Regan Registered User

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    Tom, as well as survey work, this Negus was used to determine magnetism at different parts of the globe with a pendulum device and the chronometer, and the curvature of the earth as it relates to a survey. Heavy stuff.
    Paul
     
  8. Paul Regan

    Paul Regan Registered User

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    Jim asked about the Break Circuit. Here is a close-up of it. On the left is the detent that runs on the cam that is below and attached to the third wheel. It has 31 lobes. This is even seconds. The extra one is for the 59th break. The long screw in the center is the adjuster for the contact points. On the right is the plate that holds the fixed contact. You can see the curved blue steel spring that comes in contact with the electrical connector on the tub. This plate is insulated with a sliver of ivory I believe. The other contact is simply grounded to the bowl. The exterior electrical connectors are placed as close as possible to the bowl gimbal pivot points for balance. There is a counter weight in the bowl opposite the break circuit to offset the weight of the circuit components, again for balance.
    Paul

    DSCN5971 (2).JPG DSCN5964.JPG
     
  9. musicguy

    musicguy Moderator
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    #9 musicguy, Feb 3, 2018
    Last edited: Feb 3, 2018
    Wow, this sidereal, break circuit chronometer is really great piece of American history. Thanks for sharing it with us and it’s Photos and history what a great find!

    And it’s really great looking


    Rob
     
  10. Paul Regan

    Paul Regan Registered User

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    The Board has been very quiet lately so I thought I would give an update on my Sidereal Break Circuit Negus. Thanks to a good friend I was able to acquire a period correct NY Rosewood box for my Negus. I have since mounted it in the box and cleaned the box up. It is amazing what lanolin hand cleaner, 0000 steel wool and paste wax can do for an old finish. I have not modified the box to include the electrical contacts as of yet. It fits like a glove. And yes it is documented here as a re-box. Which probably 80% of those out there are. Here are before and after pics,
    Paul

    IMG_4766.JPG IMG_5091.JPG IMG_5098.JPG
     
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  11. Paul Regan

    Paul Regan Registered User

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    I would like to bring attention to Burt Cifrulak's latest Bulletin Article. Burt has written a masterpiece story of the two years Negus Chronometer #1769 spent on the Ziegler/Fiala Polar Expedition of 1903. The fine Article appears in our latest Bulletin.
    Thank you Burt!
     
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  12. Jim Haney

    Jim Haney Registered User
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    I just received my Bulletin today and read Burt's story and was taken with his research and info in the article.
    Go Burt.
    Thanks for keeping us informed on this special timepiece
     
  13. Rhett Lucke

    Rhett Lucke Board Secretary
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    Just finished the excellent article by Burt and I couldn’t agree more with Jim.

    Thanks Burt and Paul for sharing this amazing story.
     
  14. Paul Regan

    Paul Regan Registered User

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    Thank you Jim and thank you Rhett, I feel privileged to own this Chronometer.
    Paul
     

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