NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Beware of Noon Sights this time of Year
From: Don Seltzer
Date: 2018 Mar 31, 10:22 -0400
Don Seltzer
From: Don Seltzer
Date: 2018 Mar 31, 10:22 -0400
Initially it seems puzzling as to how they could misread their compass so badly and stray so far north from their intended easterly course. Perhaps they were carried NE by the Gulf Stream for a considerable distance while pointing the ship's bow East.
It is also possible that they did not adequately understand magnetic declination. For 1815, declination would have been near zero when they left port but rapidly increasing westward as they crossed the Atlantic. By the time they reached the latitude of the British Isles, magnetic declination was about 30° west. On Sat, Mar 31, 2018 at 10:01 AM, Robin Stuart <NoReply_Stuart@fer3.com> wrote:
The dates and locations are quite specific. The error in latitude will be twice the Sun’s declination. For the Orkney’s the latitude difference is 23° and the Sun’s declination on the 19 April, 1815 was around 11°N. For Christian Sound (Kritiansund) the latitude difference is 27° and the Sun’s declination 13.5°N. It would be no easy task to construct a fanciful tale in which the differences in latitude, changes in declination and traverse times all line up so well,
Robin Stuart
