NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Captain Cook & celestial navigation
From: Roger W. Sinnott
Date: 2020 Mar 13, 17:56 +0000
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.
Roger
-----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
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
Robin Stuart
