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: Compact Lightweight Metal Sextants - Freiberger Yacht vs. Astra IIIB
    From: Bill Morris
    Date: 2012 Aug 11, 15:56 -0700

    "But my main objection is that its micrometer drum is too small and lacks a vernier scale. Even worse, its shinny surface reflects light, making it very difficult to read in many circumstances."

    For those who _must_ have a vernier, it is a simple matter to make one on paper using a computer drafting program, and then to glue it on to the index, followed by a coat of varnish. I attach some examples that can be printed out. Those with unsteady hands get three goes.

    Shine can be removed by rubbing with a piece of emery paper, say 400 grit. Some Freibergers have very respectable arc errors, but I have seen examples having errors of more than 90 seconds, two of them on the bridge of a modern container ship.

    The SNO-T, by the way, is supplied with two 'scopes,a 4 x 40 Galilean and a 6 x 32 Keplerian.

    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?

    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