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    Re: Chronometers
    From: Alexandre Eremenko
    Date: 2008 Mar 29, 15:23 -0400

    
    Dear Henry,
    
    Thank you very much for your information.
    I think our library has a reasonably old
    copy of Dutton.
    
    > The later edition of 1985 broaches
    > the subject of Quartz Chronometers ... "capable of
    > maintaining an excellent rate, with the better models
    > having a deviation of less than 0.01 seconds from
    
    On my opinion, "Quartz chronometer" is an oxymoron.
    My best electronic wrist watch (200 Euros) has a
    rate of 2 seconds PER YEAR, and my cheap Casio
    digital watch ($25)
    has a daily rate of about 1 sec per day, and this rate is
    pretty constant, so by using a daily correction, even this
    cheap watch is enough for all navigation purposes,
    even without radio signals.
    
    So I don't see any need of quartz chronometers, and I see
    no reasons why they are made at all
    (the only justification I can
    imagine is that seamen are SO conservative that they want
    to see a chronometer in a wooden box, otherwise they don't
    trust it:-)
    
    Anyway, quartz chronometers and atomic watches
    are in the same category
    as GPS: we do discuss them from time to time, but this
    is not the main topic of the list as I understand it:-)
    (Though of course, I routinely use a quartz watch
    (and even Internet) with
    a sextant in my "practical" navigation:-)
    
    BTW, there are rumors of pocket watches of early XX century
    (thus mechanical) which were equal or
    exceeded the best chronometers. If these rumors are true,
    and the price of these watches was comparable with the price
    of chronometers, then these watches should had made all
    chronometers obsolete.
    
    > Older editions of Dutton, specifically that of 1934,
    > which was my initial navigation text, details the
    > older 20th century methods and procedures as followed
    > by the US Navy.
    
    That's interesting indeed. I will check an old Dutton.
    
    > method of Chronometer comparison whereby the
    > regularity of of daily rate could be demonstrated -
    
    I understand the method of comparison of chronometers.
    (It is described in many books, including Chauvenet).
    My difficulty is in comparison of ONE chronometer with
    internet or electronic watch, to high accuracy.
    
    > There are other texts that include commentary on the
    > chronometer, Bowditch, Norie and Mixter being three
    > that come immediately to mind,
    
    Yes, indeed! My 1828 Norie indeed has a chapter on
    chronometers, which I never noticed before:-)
    
    > into technical detail as to construction.
    
    A book of Could ("Marine chronometer") was recommended
    on this list. It costs a fortune in the used
    book stores on Internet. There were rumors of a new
    reprint, and Amazon even asked $50 pre-payment
    (pre-order, whatever) so
    that the book will be sent to you after it is published.
    I ordered this. 6 months later Amazon told me that
    the publication is "postponed". And few months later
    they cancelled my order.
    
    > To increase the accuracy of reading the 1/2 second
    > beat, I have sometimes used a 1/100 second reading
    > mechanical stop watch running simultaneously with and
    > synchronized with the chronometer second hand.
    
    That's fine, I also tried to use such stop watch.
    I can perfectly synchronize it with my chronometer.
    But how to synchronize it with Internet or
    an electronic watch that beats only whole seconds?
    
    Alex.
    
    
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