NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: No sextant, no watch, no almanach, nothing
From: Trevor Kenchington
Date: 2004 Nov 7, 21:21 -0400
From: Trevor Kenchington
Date: 2004 Nov 7, 21:21 -0400
Alexandre, You wrote: >>Voyagers like the Polynesians, >>for example, who roamed the Pacific seas with >>"no sextant, no watch, no >>almanac, nothing", >> > > I suppose they also did not have compass, so DR > was not available to them, and they had to rely > on CelNav entirely. That is a false distinction. They used the stars (and other guides) to determine direction -- call that CelNav if you wish. But on the basis of such a "star compass", they then maintained a dead reckoning in the sense of holding a known course for a known time at an estimated speed. > So I would be interested to know > more details on how exactly they did it. Start with Steve Thomas' "The Last Navigator". It is an autobiographical account of his own training in the techniques and the thought patterns that go with them. Anyone who starts with Thomas' prior knowledge of Western navigation methods should be able to comprehend the Polynesian (strictly Micronesian) methods. > It is easy to imagine for me how they determine latitude. > What is really hard to imagine, that they could determine > longitude by their Cel Nav methods, even roughly. Without either chronometers or lunar predictions, I don't see how anyone would get longitude by celestial methods. And neither of those were available before Western technology achieved them in the mid-18th Century. >>An almanac just happens to be one of _our_ ways of >>passing on this sort of information. >> > > I disagree with "just one":-) > Based on what I know, it is also a "better", "superior" > way in comparison with what other cultures invented. > In the sense that it gives better precision. > Of course one can argue that other cultures did not need > better precision for their needs, with this I don't argue. > (Correct me if I am wrong here). Better precision, of course, but at a considerable cost. Long after the sextant/chronometer/almanac/sight-reduction-tables technology package diffused around the world, the great majority of vessels pushing out from shore did not (and do not) carry that package. I very strongly suspect that, at any time you care to name, the great majority of vessels (by numerical count) going out of sight of land have done so without that package of technology. I would suggest that that indicates that the package is not "better" overall for many potential users. An almanac, clearly, has little to recommend it as a way of encapsulating celestial lore for anyone who does not also carry a sextant or some equivalent instrument. So better precision, of course. But "better"? I'd not be so sure. Trevor Kenchington -- Trevor J. Kenchington PhD Gadus@iStar.ca Gadus Associates, Office(902) 889-9250 R.R.#1, Musquodoboit Harbour, Fax (902) 889-9251 Nova Scotia B0J 2L0, CANADA Home (902) 889-3555 Science Serving the Fisheries http://home.istar.ca/~gadus