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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Newton and Halley
From: George Huxtable
Date: 2007 Nov 16, 21:09 -0000
From: George Huxtable
Date: 2007 Nov 16, 21:09 -0000
Let's sum up. The following 3 pieces of evidence exist. 1. In Halley's papers, after his death (and after Newton's) a note was found, of unknown date, to him from Newton, which was then copied for the Royal Society, and published in their Philosophical Transactions, vol 42, no. 465, pages 155-6, of 1742. It described, unambigously, a two-mirrored instrument, in some detail. It referred to an "annexed scheme", which has not survived. 2. The Secretary made the following entry in the Royal Society's Journal Book, of 16th August 1699- "Mr Newton showed a new instrument contrived by him for observing the moon & Starrs, the Longitude at Sea, being the old Instrument mended of some faults, with which notwithstanding Mr Hally had found the Longitude better than the Seamen by other means". That was in Halley's presence, who was back in London in the short interval between his two Atlantic voyages. 3. Halley's Journals, for his three voyages 1798 to 1701, record latitudes found at sea to a precision which was quite unachievable by the known instruments of the day. Therefore, the conclusion is that Halley had indeed carried and used Newton's two-mirrored instrument, to measure the altitudes on which those latitudes were based. =================== To most of us, I suggest, that conclusion is inescapable, and we can consider the case as closed, unless some of that evidence is found wanting. However, for some reason Mike Daly finds it unpalatable, and he has written- "However, I can't find much to support the claim that Halley used Newton's..." Well, that's OK. I'm all for a bit of scepticism. He can accept it or not, and the rest of us will lose little sleep. It seems to me, though, that the case, made above, is sufficiently strong that it isn't shaken by Mike's failure to find further supporting evidence. Indeed, it's strong enough to require some contrary evidence before it is to be discredited. ===================== Some other matters crop up as a result of these recent postings. To my suggestion of a plausible scenario, to explain some details of Newton's words, Mike Daly responded- "Plausible scenarios are nice, but they are not good scholarship." Well, that may sound VERY superior. However, suggesting a plausible scenario is a valid counter, in the most scholarly circles, to a suggestion that something didn't happen. As long as it isn't dressed up as a proof that it did happen. And it wasn't. If Mike is offering lessons in scholarship, however, he might consider these quotations, from his recent postings, with my own comments in square brackets. When he tells us what others say, unless he provides some sort of citation, they are unchallengeable, being uncheckable.- "If he did use lunar distances, it is often suggested that he used Newton's," [Often, by whom?] "If folks are saying "Halley used Newton's original instrument", then that means the statement is false" [Who was saying that?] "Some suggest it was because Halley wasn't that familiar with Newton's instrument" [When challenged, on who were the "some", the reply was- "In exactly which books did I read that - offhand I can't remember". ] ==================== Finally, I invite Mike Daly to tell us the basis for his comment in Navlist 3863- "Perhaps because the thought of lugging around a huge brass plate with a three to four foot long telescope intimidated the navigators too much. (size, weight and cost) I don't know that anyone would have thought to shrink it down, given the original design came from Newton " Newton's note gave no dimensions for his plate, only for the telescope. So how does Mike infer that the plate was "huge", and called for shrinking down? George. contact George Huxtable at george@huxtable.u-net.com or at +44 1865 820222 (from UK, 01865 820222) or at 1 Sandy Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK. --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to NavList@fer3.com To , send email to NavList-@fer3.com -~----------~----~----~----~------~----~------~--~---