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    Re: Captain Cook & celestial navigation
    From: Roger W. Sinnott
    Date: 2020 Mar 13, 17:56 +0000
    Yes, Robin --

    I got my May issue two days ago and also noticed your letter wasn't there.  (I guess my "pull" has very little weight anymore, as I did strongly urge them to publish it.)  Sorry about that.


    -----Original Message-----
    From: Robin Stuart <NoReply_Stuart@fer3.com>
    To: rsinnott <rsinnott@post.harvard.edu>
    Sent: Fri, Mar 13, 2020 1:33 pm
    Subject: [NavList] Re: Captain Cook & celestial navigation

    As predicted Sky & Telescope has apparently chosen to ignore errors that are pointed out to them. The May 2020 digital edition has just appeared and they only acknowledge a couple of fairly simple but nevertheless egregious mistakes in the article in question.
    • A 6-minute error in determining Greenwich Time would lead to a navigator’s error of 90 nautical miles, not 6 (S&T: Mar. 2020, p. 60), when sailing near the equator.
    • When computing longitude, subtract Greenwich Time from local time and multiply by 15, not divide, as stated in Captain Cook’s Astronomy” (S&T: Mar. 2020, p. 61).
    On Navlist Frank had pointed out the first of these which represents an error of a factor of 15. The second one is an error of a factor 225 and we all missed that!

    Robin Stuart
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