NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: sextant precision.
From: George Huxtable
Date: 2005 Jun 25, 20:26 +0100
From: George Huxtable
Date: 2005 Jun 25, 20:26 +0100
Bill wrote- My Astra IIB Deluxe, like Alex's SNO-T, has a front-silvered index mirror. >Like Alex I have to use gauge blocks to align the index mirror. That may indeed be necessary, as Bill says. But that doesn't NECESSARILY follow from the fact that his index mirror is front silvered. Only if the front-silvered reflecting surface is displaced from the pivot axis will that be the case. If the framing of a front-silvered mirror has been designed to align the reflecting plane with the pivot axis of the index arm, then he should be able to eyeball the continuity of the line of the arc, just as before. George. =============================================================== Contact George at george@huxtable.u-net.com ,or by phone +44 1865 820222, or from within UK 01865 820222. Or by post- George Huxtable, 1 Sandy Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK.