A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Sean C
Date: 2016 Mar 29, 16:28 -0700
I ended up purchasing a different box sextant, made by F. Barker & Son, London. (Pictures attached.) This one has the index shades, and it appears to also have a removable filter for the telescope. The telescope itself is removable and a peep hole can be slid into place. A leather case is included. It seems to be in very good condition and the screws do not seem to have been tampered with. I was surprised to be the only bidder. This listing was less expensive than those of other sextants which appear to be in worse condition and have fewer features. I have seen as many as sixteen people watching the other listings.
Inside the lid is a paper label on which are printed "natural tangents to a base of 100". I'm familiar with how these can be used to determine the distance to an object/landmark. Do they have any useful purpose in celestial navigation?