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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Armillary shphere, search engine
From: Alexandre Eremenko
Date: 2004 Oct 30, 16:33 -0500
From: Alexandre Eremenko
Date: 2004 Oct 30, 16:33 -0500
I am very thankful to the list member who sent this reference for the Armillary spheres: http://www.hps.cam.ac.uk/starry/armillobser.html I am terribly sorry, that I could not recover this person's name and his message. (How the search engine works on this list archive is far beyond my understanding:-( Maybe someone more experienced could explain!!? The "Observational Armillary sphere" on this site seems to be an "analog copmuter" (as I conjectured before) with which you can do the same tasks as with a Star Globe. (or Wulff grid, or planispheric astrolabe). The only difference is that the Star Globe has fewer graduated circles. (Namely, 4. The modern Freiberger version has only 1 or 2 circles, but permits to solve the same problems.) Mathematically, all devices solve a spherical triangle. (I suppose with 1/2 degree precision). Some of them also include some "almanac data", mostly star positions. Alex.
