NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Portuguese shipwreck question
From: George Huxtable
Date: 2009 Nov 3, 17:03 -0000
From: George Huxtable
Date: 2009 Nov 3, 17:03 -0000
Apache Runner wrote, in reply to Frank's suggestion about a projection on which to put his mediaeval data- | Uh...because I was teaching Mercator projections last week? Because George | said so? Both? ======================= My own views shouldn't be taken too seriously on this matter. It's just that Mercator is the first projection that comes to my mind in terms of sea navigation, because it preserves the direction of bearings. But the mediaeval gazetteer that's under discussion here appears to be more related to travel by land than by sea, and it may well be that a simpler alternative, or one which preserves travel-distance better than Mercator does, may be more useful. Frank knows more about such matters than I do, and his suggestion of a conical projection should be taken seriously. The OMC website that I referred to allows for the following choices for projection- Mercator, Equidistant cylindrical, Polar stereographic, Lambert azimuthal, Azimuthal equidistant, Orthographic. But don't ask me to explain the differences between them. As for Thule, there seems little doubt that mediaeval navigators, Celts and Vikings, got that far, and that it was indeed what we now call Iceland. But that doesn't imply that every early voyager who claimed to have reached Thule really had. Those given coordinates for Is. Tule were a long way out, but then so they were for many other places on the Marseilles list. George. contact George Huxtable, at george@hux.me.uk or at +44 1865 820222 (from UK, 01865 820222) or at 1 Sandy Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK. --~--~---------~--~----~------------~-------~--~----~ NavList message boards: www.fer3.com/arc Or post by email to: NavList@fer3.com To , email NavList+@fer3.com -~----------~----~----~----~------~----~------~--~---