A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Date: 2015 Aug 1, 12:23 -0700
The idea that is underlying the double altitude method has been used extensively by French astronomers as early as from the 18th cy. Its main advantage is that it makes the observation independent of refraction. Lacaille applied it (mutatis mutandis) to establishing the right ascensions of stars (and thus that of the the sun). This was instrumental for his new solar theory 1758 which became the basis of Tobias Mayer's, and consequently for the lunar distances which he promoted. I won't be able to discuss this any further for the next 4 or 5 weeks as I am heading out on a passage within the hour. Just want to offer it as a pointer for further studies. Some of you will remember that I touched on this subject at a presentation on Lacaille in one of Frank Reed's seminars in Mystic.