NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Captain Cook & celestial navigation
From: Robin Stuart
Date: 2020 Mar 13, 09:29 -0700
From: Robin Stuart
Date: 2020 Mar 13, 09:29 -0700
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
