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    Re: Calculator v. Slide Rule for Ex-Meridian Correction
    From: Alexandre Eremenko
    Date: 2016 Jan 3, 17:19 +0000

    It never crossed y mind that a lunar distance can be reduced with a slide rule:-)
    It seems that a much larger precision is required for a lunar distance...
    And I missed this discussion.
    Can you suggest how to find it?
    (The dates, or titles of messages).
    From: NavList@fer3.com [NavList@fer3.com] on behalf of Brad Morris [NoReply_Morris@fer3.com]
    Sent: Sunday, January 03, 2016 11:29 AM
    To: eremenko@math.purdue.edu
    Subject: [NavList] Re: Calculator v. Slide Rule for Ex-Meridian Correction
    Hello Alex
    Glad to see you!
    There has been some discussion of performing the lunar distance computation 
    with a slide rule.  What is your estimate of the number of significant digits 
    for the lunar distance computation?
    On Jan 2, 2016 4:42 PM, "Alexandre Eremenko" 
    > wrote:
    This kind of calculation requires few significant digits, and thus can be done 
    with a slide rule. You can also time how much it takes by hand with pencil, 
    as it was done in the old times, without a calculator and without a slide 
    rule. However the main calculation which we do in CelNav, solving a spherical 
    triangle, requires 5-6 digits, and this is not possible with a slide rule. 
    Perhaps for this reason a slide rule is not in the list of standard equipment 
    for a celestial navigator.
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