NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Instrument for solving spherical triangles
From: Geoffrey Kolbe
Date: 2012 Apr 26, 13:36 +0100
From: Geoffrey Kolbe
Date: 2012 Apr 26, 13:36 +0100
List member Wolfgang Koeberer gave a very interesting talk on such instruments to the recent National Maritime Museum conference in Greenwich (England). The earliest example he showed dated from the 16th century, I believe. They were re-invented regularly over the succeeding centuries and all had the feature of four intersecting circles of adjustment, from which the spherical triangle could be solved. The astro-compass was probably the latest (and last) instrument to be commercially made in that tradition and Wolfgang said that with care, an accuracy of one degree was possible using the astro-compass. Geoffrey At 13:19 26/04/2012, you wrote: >For this one we have a patent with good pictures in our list archive: >http://fer3.com/arc/img/106506.fix_finder.pdf >Unlike the bubble octant, these things are very rare on e-bay, >from which I conclude that not so many were produced. > >Alex. > >P.S. My son who had a pilot training in 1994, and who works in >the airspace industry says that he has never seen a sextant >(and it was never mentioned during his training) until I showed him one. > >On Thu, 26 Apr 2012, G Becker wrote: > >> >>Here is a link to a newspaper blurb on the Zerbee Celestial Fix >>Finder... the caption says it was revolutionary in jet navigation. :/ >> >>http://news.google.com/newspapers?nid=2206&dat=19511028&id=FJMzAAAAIBAJ&sjid=YOkFAAAAIBAJ&pg=3196,6472009 >>---------------------------------------------------------------- >>NavList message boards and member settings: www.fer3.com/NavList >>Members may optionally receive posts by email. >>To cancel email delivery, send a message to NoMail[at]fer3.com >>---------------------------------------------------------------- >> >> >> >> >>: http://fer3.com/arc/m2.aspx?i=119269 >> >> > >
