NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Dipmeter: was [NAV-L] Wires, back sights and collimation
From: Frank Reed CT
Date: 2004 Dec 1, 15:17 EST
From: Frank Reed CT
Date: 2004 Dec 1, 15:17 EST
Alex E wrote:
"This raises an interesting general issue: why do they never fix
the
mirrors rigidly on a sextant, so that they are strictly perpendicular
to the frame and dispense with the adjustment screws?
Apparently it cannot be guaranteed that they remain perpendicular..."
mirrors rigidly on a sextant, so that they are strictly perpendicular
to the frame and dispense with the adjustment screws?
Apparently it cannot be guaranteed that they remain perpendicular..."
Presumably because the mirrors have to be re-silvered now and then. You
could fix the frames rigidly but it would be hard to guarantee that the mirrors
would be perpendicular when remounted.
Frank R
[ ] Mystic, Connecticut
[X] Chicago, Illinois
[ ] Mystic, Connecticut
[X] Chicago, Illinois