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    Re: Quicker Ex-Meridian Formula for Slide Rule or Calculator
    From: John Brown
    Date: 2016 Dec 2, 02:40 -0800

    Greg and Francis

    Good luck in your searches for the Blundell Harling Academy 504.  I hunted all over the place for years and finally found one which was part of a very large private collection of scientific, engineering and navigational instruments in New Zealand.  After some negotiations I bought it.

    It arrived in its original, pristine packaging, looking as though it had never been opened. I am now reluctant to actually use it.

    From the same collection I also acquired a Sundowners Almanac, 'the solar slide rule', by the Sundowners Almanac Co of San Diego, dated 1988 -  in as new condition also.

    There are some similarities with 2102-D and it came with seemingly full instructions for use,  but I have yet to get to grips with it.

    If anyone is interested I can post pics.

    Regards to all


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