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    Re: sextant precision.
    From: Geoffrey Kolbe
    Date: 2005 Jun 20, 10:11 -0700

    >
    >At the point where you have set aside the welder's glass, and swung in the
    >dense shade in the index-mirror view, you still have the full brilliance of
    >the Sun in the horizon-mirror view. Unless you introduce a similarly dense
    >shade into that direct view, your eye will be quite unable to take it. But
    >if you do that, you are measuring, not the error of the upper shade, but
    >the combined error of two shades (just as Lecky described), which was NOT
    >the object of the exercise.
    
    George, are you able to remove the index mirror shade and rotate it  - even
    using plasticene or some other jury rig to hold it in place while you see
    if the IC has shifted....?
    
    Geoffrey Kolbe
    
    
    

       
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