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    Lunars hard to shoot
    From: Paul Hirose
    Date: 2000 Sep 13, 4:29 AM

    Thanks to those who replied to my query on shooting lunars.
    
    It was a little surprising to see Carl Herzog's statement that the
    choice of whether to use the horizon glass or index mirror for the
    Moon is mainly a question of physical convenience for the navigator.
    I'd expect the index shades to be much darker, since they have to
    make the direct rays of the Sun safe to view. (Remember, I own a
    bubble sextant but no marine sextant.)
    
    I've seen old engravings of quadrants, but never noticed the second
    sight line George Huxtable mentioned. But in "From Sails to
    Satellites" by J.E.D. Williams (excellent book!) there is a photo of a
    1750 quadrant by J. Bird. That instrument appears to have two horizon
    glasses, each with its own index mirror shade glass! I don't think
    this is what George is talking about -- the horizon glasses (if indeed
    that is what they are) are parallel as well as I can judge. Doesn't
    seem possible one could be used for a back sight.
    

       
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