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    Re: Chronometers
    From: James Whitson
    Date: 2008 Mar 29, 21:45 -0400
    Mr. Eremenko- There are some ancient pocket watches contracted by the early railroad moguls called "regulators" that were considered the most accurate time keepers made. My previous skipper carried one and swore by it. -Jim

    > Date: Sat, 29 Mar 2008 15:23:07 -0400
    > From: eremenko@math.purdue.edu
    > To: NavList@fer3.com
    > Subject: [NavList 4766] Re: Chronometers
    > 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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