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    Re: How does the AstraIIIb split mirror work?
    From: Jim Thompson
    Date: 2004 Apr 23, 10:04 -0300

    > -----Original Message-----
    > From: Navigation Mailing List
    > [mailto:NAVIGATION-L@LISTSERV.WEBKAHUNA.COM]On Behalf Of Joel Jacobs
    > Unless all your tests were made with a perfectly vertical instrument it is
    > hard to judge the cause of the variations.
    I have seriously been thinking about mounting the sextant on a camera tripod
    to hold it solidly in 3 dimensions, but the boat just arrived in the yard
    from storage and my priorities have just changed.
    > 4. I found Paul's suggestion noteworthy. However, I don't
    > understand how if
    > you block the clear portion of the horizon mirror from the mirror's front,
    > how you can have an object seen on a non-reflective surface.
    > Did you block it from the front or the back?
    From the back, which would allow the index mirror's image to reflect off the
    clear-window glass on the horizon mirror.  I think this proves that the
    clear window has reflective properties?
    Good point -- I will repeat the experiment by blocking from the front.

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