NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Sextant mirrors
From: Fred Hebard
Date: 2007 Oct 8, 21:05 -0400
From: Fred Hebard
Date: 2007 Oct 8, 21:05 -0400
Some sextant mirrors have the reflective surface on the front, but, traditionally, they've been on the back, I suppose in order to protect the reflector; they allow coating of the back and sides with salt- and water-resistant materials. Yes, rear-coated mirrors give multiple images, but they are easy to distinguish. On Oct 8, 2007, at 8:54 PM, Jim wrote: > > Issue 96 of the Nav.Found,newsletter has an article concerning > mirrors.In which the author suggests that in an emergency the mirrors > may be replaced,using any type of mirror available e.g.vanity,hand > etc.It is my understanding that sextant mirrors are manufactured from > an optically flat material,which to me means that not only the two > sufaces be flat but,also the refractive index.Is this correct.I have > read that using ordinary glass results in multiple images. > Jim Martin. > > > > --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to NavList@fer3.com To , send email to NavList-@fer3.com -~----------~----~----~----~------~----~------~--~---
