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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Eclipses of Jupiter's moons: Did ships tend to carry the requisite equipment?
From: Fred Hebard
Date: 2004 Feb 13, 14:09 -0500
From: Fred Hebard
Date: 2004 Feb 13, 14:09 -0500
Aubrey, in fictional fact, is a Fellow of the Royal Society. Did not the Nautical Almanac of that time include data allowing determination of longitude from observation of Jupiter's moons? This would suggest the practice was somewhat common during that time. The technique also would not require much of a telescope, and the tripod need not be very fancy. On Feb 13, 2004, at 12:48 PM, William Allen wrote: > Carl, > > In my readings of this epoch of the Royal Navy, it would have been very > rare indeed for an average captain (average wealth and skills) to own > and carry on board such a telescope and to know how to use it to take > these type of sights - and reduce them to useable longitude data. I > have not found any precedent for this type of activity in O'Brian's > alleged role model for Aubrey (at least for the early books), the > famous > super-captain Thomas Cochrane. See for example "The Autobiography of a > Seaman" by Admiral Lord Cochrane, first published in 1860 with many > subsequent re-issues. > > However, I have read all the Aubrey/Maturin novels and it seems to me > that the author (pseudonym O'Brian, an Englishman born Richard Patrick > Russ, who in reality did not ever serve on-board a Royal Navy ship > during his stint in the armed forces during WWII) is depicting his > central character as a science dilettante who is willing to experiment > with new astronomy and navigation ideas. I believe Aubrey has even > submitted one or more papers to the Royal Society on the "Nutations of > the Earth", which I believe had something to do with the procession of > the poles. This makes him a worthy colleague for the cerebral and > multi-talented doctor (not just surgeon), Steven Maturin. And "Lucky > Jack" Aubrey would have had the money from his prize winnings to > purchase the needed equipment for Jupiter's moons sights -- at least in > the middle of his career before he starts to squander his savings. > > Certainly there were some Royal Navy ships that carried special > equipment with specially trained officers to perform the sights of > Jupiter's moons on distant shores (read on the land), but I am under > the > impression that these trials were earlier (maybe 1760 to 1780? Perhaps > under the instigation of Maskelyne or his cronies?) than Aubrey's > captain's commission. > > I have always viewed the Jupiter's moons sights as a slight literary > license that -- although historically had been done -- was primarily > included to enhance the reader's impression of the intelligence and > scientific prowess of the Aubrey character. However, this has not in > any way taken away my enjoyment and enthusiasm for the books. > > Bill Allen > > -----Original Message----- > From: Navigation Mailing List > [mailto:NAVIGATION-L@LISTSERV.WEBKAHUNA.COM] On Behalf Of CarlZog > Sent: Friday, February 13, 2004 8:49 AM > To: NAVIGATION-L@LISTSERV.WEBKAHUNA.COM > Subject: Eclipses of Jupiter's moons: Did ships tend to carry the > requisite equipment? > > A question arose on a mailing list of Patrick O'Brian fans that I > thought > this group may be better prepared to answer: > > Apparently, in one of his books, O'Brian's main character is carrying a > fairly substantial telescope on board with which to determine longitude > by > the eclipses of Jupiter's moons. > > Presumably, he would be conducting these measurements on some remote > coastline and not on board. But even assuming that much, the question > was, > how likely was a British naval ship or its captain to have carried or > used > such equipment circa 1800? > > His fan are prone to believing that most of O'Brian's details are drawn > from > contemporary source material. While the method is commonly discussed in > texts of the period, I'm uncertain how prevalent the actual practice > was. > > Carl Herzog > > -----Original Message----- > From: Navigation Mailing List > [mailto:NAVIGATION-L@LISTSERV.WEBKAHUNA.COM] On Behalf Of CarlZog > Sent: Friday, February 13, 2004 8:49 AM > To: NAVIGATION-L@LISTSERV.WEBKAHUNA.COM > Subject: Eclipses of Jupiter's moons: Did ships tend to carry the > requisite equipment? > > A question arose on a mailing list of Patrick O'Brian fans that I > thought > this group may be better prepared to answer: > > Apparently, in one of his books, O'Brian's main character is carrying a > fairly substantial telescope on board with which to determine longitude > by > the eclipses of Jupiter's moons. > > Presumably, he would be conducting these measurements on some remote > coastline and not on board. But even assuming that much, the question > was, > how likely was a British naval ship or its captain to have carried or > used > such equipment circa 1800? > > His fan are prone to believing that most of O'Brian's details are drawn > from > contemporary source material. While the method is commonly discussed in > texts of the period, I'm uncertain how prevalent the actual practice > was. > > Carl Herzog >