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    Re: No Lunars Era
    From: Alexandre Eremenko
    Date: 2004 Dec 6, 16:19 -0500

    I think, Chauvenet explains very well, why there
    was no "Lunars era":
    
    "The navigator having found his longitude
    "by chronometer" wishes to verify it by "lunars".
    He takes a set of distances with upmost care and
    reduces them... His results are liable to the three
    sources of error above mentioned, and...
    the distance would produce in the longitude a mean error
    of 38 seconds in time. Now his chronometer must have performed
    very badly to be in error of 38 seconds...
    He takes another set of distances and finds a still
    greater discrepancy...
    
    and upon making port finds that his chronometer is right."
    
    This was written in 1868, when the time for the "Lunars era"
    was gone long ago:-)
    
    The time for the "Lunars era" was probably 60 or 70 years
    earlier when chronometers "were expensive".
    
    Notice that the price of a "good sextant" necessary for
    decent lunars was about 4 times that of the "good quadrant".
    of the same era.
    
    (I don't know much about the price of chronometers).
    In  our time good chronometers are about 2-3 times more
    expensive than good sextants (on e-bay), but I understand
    that this is not a fair indicator:-)
    
    Alex.
    
    
    

       
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