NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Troughton and Simms
From: Alexandre Eremenko
Date: 2013 Jan 12, 14:27 -0500
From: Alexandre Eremenko
Date: 2013 Jan 12, 14:27 -0500
Norm, > I just realized how TRULY wonderful the sextant vernier is. 10 seconds is > a very small angle, I agree that these silvered scales are really wonderful. One cannot appreciate this from the pictures. I remember my excitement when I first saw my pocket sextant scale through the magnifying glass. It reads only to 1' but the whole 150 d scale is just 3 inch long! By the way I noticed an interesting statement in the Simms book on sextants. He recommends using pocket sextants for all observations AT SEA, except the lunars. The rational is "to preserve the precious instrument from elements":-) I've never heard before that pocket sextants were used at all at sea. Norie says that the sextant is to be used for lunars, but an octant for altitude observations. But this is another matter. Alex. sight but it's really more astounding than that. The arm > only moves 5 seconds to affect a visual angle change of 10 seconds. Not > telling the board anything new it's just that I love it all. > > Norm > ---------------------------------------------------------------- > 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=121898 > > >