Welcome to the NavList Message Boards.

NavList:

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

Compose Your Message

Message:αβγ
Message:abc
Add Images & Files
    Name or NavList Code:
    Email:
       
    Reply
    Scales used on Bygrave
    From: Gary LaPook
    Date: 2010 Feb 18, 16:35 -0800

    A while ago we had an ongoing discussion of what scales were actually used on the Bygrave and the German version, the HR1. Wolfgang just posted an excerpt of a book in German which supplies additional information on this issue. I am attaching pages 166 and 167 of this book. Even without speaking German I think it is clearly stated on page 167 that the inner scale is a log cotangent scale and the other scale is a log cosine scale. Also page 166 states the formulas that are actually solved with these slide rules which identify the scales as a cotangent scale and a cosine scale.
    ------------------------------------------------------------------
    Some of you may be interested in the linked pages
    of "Lehrbuch der Navigation"
    Bremen 1943, volume II
    They show different aircraft sextants and describe
    their use and properties. (in German...)

    Most intersting is the last paragraph on mechanical
    calculation devices for the celestial triangle,
    including HR1.
    It reads:
    "The altitude slide rule manufactured by Dennert & Pape
    has proven useful and was introduced to navy and air
    force."
    Another hint that MHR1 is not likely to mean "marine" HR

    Wolfgang

    Pdf documents, zip compressed are linked ~ 5MB
    ----------------------------------------------------------------
    NavList message boards and member settings: www.fer3.com/NavList
    Members may optionally receive posts by email.
    To cancel email delivery, send a message to NoMail[at]fer3.com
    ----------------------------------------------------------------

    --------------------------------------------------------------------


    gl
    ----------------------------------------------------------------
    NavList message boards and member settings: www.fer3.com/NavList
    Members may optionally receive posts by email.
    To cancel email delivery, send a message to NoMail[at]fer3.com
    ----------------------------------------------------------------

    File:

      

       
    Reply
    Browse Files

    Drop Files

    NavList

    What is NavList?

    Get a NavList ID Code

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

    A NavList ID Code guarantees your identity in NavList posts and allows faster posting of messages.

    Retrieve a NavList ID Code

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

    Email Settings

    NavList ID Code:

    Custom Index

    Subject:
    Author:
    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