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    Re: Quicker Ex-Meridian Formula for Slide Rule or Calculator
    From: Francis Upchurch
    Date: 2016 Dec 1, 11:22 -0800


    I've been looking for one of these for over a year and have failed to find a single one on ebay or similar. Anyone have any ideas?

    Alternatively, does anyone have accuarate copies of the scales so I can make one, as per my Bygrave replica of a few years ago?

    PerhapsBob Goethe could incorporate some of the best features, including the XM mark into his interesting navigators slide rule?

    Meanwhile, I'm sticking to my Fuller 3 which has cosines, sines, tangents (albeit only to 45°, but easy to adjust for > 45°) and 4-7 decimal places and in my hands anyway, just as quick as the 10" rule.( and I've just added the XM mark with fine pencil.) I still think the cylindrical Bygrave replica is the best and quickest  way to do LOPs and Great Circle.(except Browne-Nassau, which is quicker than Bygrave, but slightly less less accurate)

    Happy to be corrected.


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