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: Sextant manufacturers
    From: Michael Daly
    Date: 2007 Oct 25, 17:47 -0400

    Alexandre E Eremenko wrote:
    > Perhaps a list of dividing engins would be shorter
    > (and more interesting) than a list of "makers":-)
    > But harder to make.
    duc de Chaulnes, 1768
    Ramsden, 1773  first significant "public domain" design
               (by virtue of Crown financing)
    Troughton E., 1778 (based on Ramsden's but improved accuracy)
    Lenoir, 1783
    I put this stuff on Wikipedia on the "Dividing engine" article but would
    like to carry it forward a bit into the 19th c.
    One thing I'd love to find is a graph I remember seeing in a
    book/article about 20 years ago.  It showed the improvements in accuracy
    of dividing engines over time.  It started with John Bird and ended in
    the 19th C, IIRC.  (Bird didn't use an engine but a series of beam
    dividers etc).  If anyone knows where such a graph is, please let me know.
    To post to this group, send email to NavList@fer3.com
    To unsubscribe, send email to NavList-unsubscribe@fer3.com

    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