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    Re: accuracy of Cook's lunars
    From: Alexandre Eremenko
    Date: 2013 Jan 6, 23:59 -0500

    Yes, and I did this.
    From my analysis of observations in Point Venus, I concluded that
    approximately 1/2 of the average error in longitude was due to
    the ephemerides they used and 1/2 to observation errors.
    
    You may look at the details in my article
    http://www.math.purdue.edu/~eremenko/Navigation/Accuracy/pointvenus.pdf
    
    The study of ephemerides is easy: you just compare their almanac with
    the modern one for those dates.
    
    The study of observation errors are harder because not all details
    are recorded in the source available to me.
    
    Alex.
    
    
    > I wonder if the ephemeris especially of the moon as used by Cook can still
    > be studied today. Naturally, Cooks errors cannot have been any smaller
    > than the ones of those.
    >
    > An accurate calculation of the moon's ephemeris is a extremely intricate
    > business and was not developed by his time. To get an idea of the immense
    > difficulties you might want to read the attached article from an 1899
    > issue of "The Observatory".
    >
    > I suspect that Cook's errors were mostly caused by the lack of an accurate
    > ephemeris of the moon.
    >
    > Does anyone know more about this?
    >
    > h
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