A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Lars Bergman
Date: 2019 Dec 23, 13:35 -0800
Further to my post of 21 December, I have now studied the sights on the link that Frank provided
and there are a few interesting details that can be detected. First we can see that the chronometer rate applied is 3.7 seconds/day gaining. It is used on all days from 27 November up to and including 5 December, 1852. The three lunars on 2-4 December show the chronometer is 2m38s, 1m17s and 3m21s respectively, too fast compared to the used rate, but no adjustment to the chronometer error is applied. On 28 November the Noon longitude is determined by an equal altitude observation, about 5 minutes before and 5 minutes after LAN. Also on 3 December is a similar EA observation squeezed in. Time sights not connected with lunars are performed in the afternoon, the Sun bearing between 255° and 257°.
A few number of miscalculations can be found, but no one so large as to be obvious.