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    Re: Dipmeter: was [NAV-L] Wires, back sights and collimation
    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..."
     
    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
       
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