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    Re: No Lunars Era
    From: Frank Reed CT
    Date: 2004 Dec 6, 19:32 EST
    Ken M wrote:
    "I have to do a lot of
    double checking to eliminate errors but I think that in the days when log
    tables were in common use and arithmetic calculation was heavily drilled
    at school, a lunar could easily be done in 30 minutes by an experienced
    I agree that they could be done with relatively little time. I would say 20 minutes with a little experience, but the idea that this was "common math" I don't believe at all. The only thing a navigation instructor could take for granted in his students was knowledge of basic addition and subtraction. But really, that's all you need. Sometimes a blank slate is easier to work with.
    "Confidence in the result would come from comparing the lunar longitude with the ded reckoning."
    Ded instead of dead? That might be another interesting topic for discussion.
    But to your point, the comparison with the DR longitude was the ONLY way that navigators could get confidence in their results and sometimes too much confidence. It's easy to subconsciously "adjust" lunars, both in the observations and the calculations. How often did navigators work back through their calculations and find an error when none was present in order to bring their lunar longitude into line with their DR longitude?
    Frank R
    [ ] Mystic, Connecticut
    [X] Chicago, Illinois
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