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    Re: Measuring Dip in the 18th Century
    From: Brad Morris
    Date: 2013 Dec 29, 01:27 -0500

    http://www.dehilster.info/index.php?doc=http://www.dehilster.info/instrumenten/davis-quadrant/index.html

    On Dec 29, 2013 1:26 AM, "Alexandre Eremenko" <eremenko@math.purdue.edu> wrote:

    Brad,
    
    >http://www.dehilster.info/index.php?>doc=http://www.dehilster.info/instrumenten/davis-quadrant/index.htmlto
    
    Unfortunatey, this reference does not work:-(
    
    Perhaps I did not make my point clear. Let me try again.
    We see a dip table made in XVI century.
    We can easily check it by comparing with modern almanac.
    It does not show 10' errors, does it?
    
    Conclusion: They could measure angles in XVI century with
    about 1' accuracy.
    Now I ask: with what device? I conjecture that this was something similar to
    backstaff.
    
    On my opinion, all arguments about GPS and modern
    obsession with many digits
    which
    Frank and you give, are not related to this question.
    
    Alex.
    
    
    
    
    
    

    : http://fer3.com/arc/m2.aspx?i=126014

       
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