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
    Name or NavList Code:
    Re: Sextants in Little Rock
    From: Bill Morris
    Date: 2010 Jan 8, 23:15 -0800

    I very much enjoyed reading the old salt's story.

    I hope Henry won't mind my correcting his terminology for the micrometer sextants. They do use a rack, a term inherited from watch and clock makers and meaning a toothed segment of a circle, but the only real sextant that has a pinion,a gear wheel with a small number of teeth, usually fewer than 12) is the box sextant (see attachment for an interior view). Nearly all nautical micrometer sextants use a short length of a helical thread, a worm, to engage with the rack. The one exception that I know of is the Freiberger Skalensextant, that has an internal glass scale divided to degrees, viewed through a microscope having a micrometer eyepiece, which allows reading directly to one minute and estimation to 30 seconds.

    Bill Morris
    New Zealand
    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


    Browse Files

    Drop Files


    What is NavList?

    Get a NavList ID Code

    (please, no nicknames or handles)
    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 Settings

    NavList ID 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