Craig wrote: .......48 volumes of navigational tables were somewhat bulky......... .......This, in a nutshell, is how celestial navigation works (more or less)...... Rob wrote: ........The position of the stars does not tell you the LONGITUDE....... Joe wrote: "That's not too different from the Pacific navigators who used different cues, perhaps, but over the generations had reached conclusions about their reliability and how to interpret them..." Craig, that was a wonderful description with plenty of clues to chase. I wasn't sure when you talked about needing an accurate clock whether you mean't accurate over months so as to reference back to GMT or just accurate for an hour or two to do the celestial measurements, but after following up some of the key ideas you described I'm guessing you mean't the latter. Anyway many thanks indeed, for a clear and interesting outline. Robert, You're right of course. I thought about it and went back to the books and realised I should have said the stars and the planets and their moons. Then longitude can be measured using the tables that Craig mentioned; first espoused by Newton, written by Mayer and then put into practice by Maskelyne, Harrison's arch nemesis. I believe Australia was discovered by Cook using this method. As you say its a big island. It may have been Paul Theroux who said Australia's inhabitants were under the illusion they were Pacific Islanders? Anyway that's the sort of thing I had in mind 17km off shore wondering how one would manage with a featureless horizon. Thank heavens for the bulk carriers and cigarette boat racers that brought me back to earth:~) Joe, That's pretty much what I was trying to say. Seems as if some measure of time is needed as well. But I know from market gardening in the 60's that ancient gardeners don't need clocks to tell the time, Imagine the same could be true of islanders! Thanks everyone and all the best, PeterO *************************************************************************** PaddleWise Paddling Mailing List - Any opinions or suggestions expressed here are solely those of the writer(s). You must assume the entire responsibility for reliance upon them. All postings copyright the author. Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************Received on Thu Jul 29 2010 - 04:26:59 PDT
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