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    Re: Mirror recoating
    From: Alexandre Eremenko
    Date: 2019 Mar 26, 21:09 +0000

    Tony,
    
    1. The advise to blaken the back surface is taken from an old sextant book.
    
    2. Your geometry is wrong: assuming that the front and back surface are parallel,
    t does not matter which one is reflecting. And it does not matter whether the axis
    passes through the plane of the surface or not.
    
    Theorem. The ray from the sun is rotated by exactly 2 times the angle between
    the index and horizon mirror. 
    
    So moving any mirror parallel to itself, does not change this.
    
    Alex.
    
    

       
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