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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Joshua Slocum's navigational methods
From: Fred Hebard
Date: 2005 Apr 17, 13:02 -0400
From: Fred Hebard
Date: 2005 Apr 17, 13:02 -0400
On Apr 17, 2005, at 5:04 AM, George Huxtable wrote: > Frank Reed revisits the question of Slocum's navigation. > > I was (somewhat reluctantly) convinced by his arguments, in that > earlier > correspondence in 2003, to the effect that there's no evidence of more > than > a single lunar-distance observation in Slocum's whole > circumnavigation. And > in describing that observation, Slocum showed such delight and pride > in it, > that if he had taken other lunars on other legs of the voyage, he would > surely have at least mentioned them. > > So I now agree with Frank, that over Slocum's solo voyaging, there's no > further evidence of reliance on lunars than that one example. > Yes, I agree the only evidence for a lunar in Slocum's book is that one observation in mid Pacific. However, I believe the reason Slocum showed such delight and pride in it was that he also uncovered an error in his tables due to the strong disagreement between his initial calculated position and his DR position. Frank Reed responded to this argument claiming that Slocum had not uncovered an error in the table but rather had merely corrected a blunder. I see no reason to suppose that Frank's claim is true, but rather prefer to take Slocum at his word. Given that lunars are a rather difficult observation and involve a different computation than usual, I believe that Slocum was performing them on a regular basis, which is what gave him the confidence to believe that the error he describes fell in the tables rather than in his observations or in his calculations, such that he could uncover the source of the error in the first place. Fred