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    Re: The Navigator’s Slide Rule, wh ich has in the past, been mentioned on nav list
    From: Art Leung
    Date: 2022 Jan 24, 06:47 -0800

    The Bygrave/MHR1 cylindrical slide rules were WW-II era devices.  I wrote up an article on Bill Morris' sextantbook.com that describes a reproduction that Bill had made (using data files and materials found here on NavList) which can be found here: MHR | Search Results | The Nautical Sextant (sextantbook.com)

    If you have not seen these articles, I highly recommend them: 

       PositionLineSlideRules.pdf (rechenschieber.org)

       Collecting_DennertPape_HR.pdf (rechenschieber.org)

    You will find that real MHR1s will come on sale on eBay but be prepared to spend a lot of money to get one.

    There was a Poor's Line of Position Computer that recenty came up on eBay: Line of Position Computer Mechanical Navigator For Ships and Aircraft | eBay

    If you look up "Flat Bygrave" here on NavList, you will also find the means to easily create a flat version of the cylindrical Bygrave.

    -- Art

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