Talk:Mural instrument

Bogus quadrant removed
If the first known quadrant belonged to al-Khujandi of 994, then the "reknowned quadrant of Ptolemy from 150 AD" must be bogus, unless someone can provide any source supporting such an Alexandrian quadrant. The Hipparchus article claims that all star measurements presented in Ptolemy's are all belong to Hippy's base, and Hippy used an astrolabe. I can imagine that. So "Ptollies reknowned quadrant" is probably a grasp into the blue, unless, as said, there's an outside source providing info about such a quadrant.  Said: Rursus   ☻   19:24, 16 April 2008 (UTC)


 * Just to clarify: nobody's actually lying here - there is possibly a mural quadrant built in Alexandria in memory of Ptollie. Or: he used some such for planet positions (not star positions), but the article may be confused about what's a quadrant or some such (f.ex. big astrolabe).  Said: Rursus   ☻   19:40, 16 April 2008 (UTC)


 * The first known mural sextant was in 994. Ptolemy's plinth was not invented by him but was already in use.  He is the first to describe the instrument.  No one's lying; they are talking about two different things.  --Michael Daly (talk) 22:25, 16 April 2008 (UTC)