Welcome to the NavList Message Boards.


A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding

Compose Your Message

Add Images & Files
    Re: Bygrave position line slide rule
    From: Zvi Doron
    Date: 2004 Mar 18, 22:14 -0000

    Based on the information and images Mr. Koberer kindly sent me and on some
    details and a drawing from Weems' book Air Navigation I have now built a
    fully working model of the Bygrave position line slide rule. It is 2-3 times
    larger than the original and is quite accurate, giving calculated positions
    to within about 1' of arc (1 nautical mile) with the inputs being Dec, Lat
    and LHA, so in effect it replaces the normal sight reduction tables. It took
    some 8 hours of work to make. Do contact me if you are interested in
    Kind regards
    ----- Original Message -----
    From: Zvi Doron 
    Sent: 28 February 2004 16:01
    Subject: Bygrave position line slide rule
    > Hello,
    > Henry Hughes & Son of London, England used to make a cylindrical 3 part
    > position line slide rule for astro navigationsometims called "Bygrave"
    > worked on the principal of solving two right angle triangels instea of the
    > complete PZX in one calculation. Francis Chichester used one on his epic
    > solo flight across the Tasman Sea (1931) and Weems in his book "Air
    > Navigation - British Empire Edition" gives a drawing and a few details. I
    > could not find any reference to it on the web.
    > Has anyone - ever used one? got one? seen one? knows if they can be had
    > for how much? Any information will be gratefuly received.
    > Thanks
    > Zvi

    Browse Files

    Drop Files


    What is NavList?

    Join NavList

    (please, no nicknames or handles)
    Do you want to receive all group messages by email?
    Yes No

    You can also join by posting. Your first on-topic post automatically makes you a member.

    Posting Code

    Enter the email address associated with your NavList messages. Your posting code will be emailed to you immediately.

    Email Settings

    Posting Code:

    Custom Index

    Start date: (yyyymm dd)
    End date: (yyyymm dd)

    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site