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    Re: Clockmaker John Harrison vindicated
    From: Hanno Ix
    Date: 2015 Apr 20, 13:08 -0700
    These remarks refer to precision pendulum clocks and their development in Germany
    in 1800's.

    Up to the mid 60's the University of Stuttgart / Dept. of Horology and Micro mechanisms
    provided time signals for the local radio station and industry - and their reference was
    a pendulum clock just as Geoffry described. It had a ~1m pendulum and an amplitude
    of about 3 deg. I don't remember the specified accuracy.

    They found that a major contribution to its accuracy and stability was the wall to
    which the clock was attached. It needed to be detached from the building altogether.
    So this clock was located in the basement of the institution and hung from the side
    of a big block of concrete, perhaps 1m * 1m* 3m, which had its own foundation in the ground.

    Another researcher/inventor was Schuler of the Schuler-pendulum-fame whose
    ideas are still implemented in modern inertial navgation systems.
    NASA published the attached article about his electrically driven precision
    pendulum clock - in German :(  I add this for the benefit of the German speaking
    members of the list.


    On Mon, Apr 20, 2015 at 3:31 AM, Geoffrey Kolbe <NoReply_GeoffreyKolbe@fer3.com> wrote:

    On Mon, Apr 20, 2015 at 7:01 AM, Bill Morris <NoReply_Morris@fer3.com> wrote:


     I agree with Geoffrey that if the clock was sealed hermetically in a case it would have been  isolated from changes in atmospheric pressure, and I wonder how then the clock was wound. 

    ​This gives a good description of the Burgess B clock


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