NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: interesting navigational device
From: Alexandre Eremenko
Date: 2012 Apr 16, 08:40 -0400
From: Alexandre Eremenko
Date: 2012 Apr 16, 08:40 -0400
This is a simple device which permits you to solve the spherical triangle graphically with about 0.5 degree accuracy. When I was a child I made such thing myself. (Of two sheets of paper rather than plastic). Same principle was used in astrolabias. I suspect this is what stereographic projection was invented for (Sometime in Hellenistic Alexandria). Alex. On Mon, 16 Apr 2012, Gary LaPook wrote: > > > http://www.nasm.si.edu/collections/artifact.cfm?id=A19700379000 > > gl > > > > > > > : http://fer3.com/arc/m2.aspx?i=119092 > > >
