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    Re: � � � Re: David Thompson's Navigational Technique
    From: Ken Muldrew
    Date: 2004 May 31, 14:11 -0600

    On 31 May 2004 at 15:03, Bruce Stark wrote:
    
    > The point is, 1800 was not a leap year. It isn't divisible by 400.
    > Wasn't this the cause a big foofaraw, and a humiliation for Moore? For
    > Oct. 11th the d eclination is given as 7? 24' south. For Oct. 12th, 7?
    > 47' south. Is that correct?
    
    Thompson only writes down the sun's declination when he actually uses
    the sun for a lunar (when he uses a star he only writes down the
    sun's right ascension). In this case, I think the lunar is done on
    the 11th, but entered into his journal on the 12th, although you can
    see from the scans that it's tough to tell for sure. I read the
    declination as 7? 29' S from this entry. The lunar is taken at 20:47
    local time on the 11th. Since their time starts at noon, this would
    be 8:47 AM on the 12th by our present reckoning. The longitude by
    account gives a time of about 7 hours 39 minutes so Greenwich time
    would be about 4:26 on the 12th. The online Nautical Almanac gives a
    sun declination of 7? 29' S for this time and date, exactly in accord
    with what Thompson writes.
    
    Ken Muldrew.
    
    
    

       
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