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: Smallest direct reading on sextant veriers
    From: Frank Reed
    Date: 2014 Dec 5, 10:38 -0800

    Robert Cagle, you asked:
    "Can anyone inform me on what the smallest direct reading would have been on a sextant that would have been used in 1818? In other words late 18th and early 19th century sextants?"

    Sextants, which were used almost exclusively for lunars in this period, had verniers which typically could be read to 10 seconds of arc. Quadrants (usually called "octants" today) which were used for all other navigational sights, besides lunars, typically could be read to 1 minute of arc. There are no 'laws' on any of this. There was considerable diversity in instruments and usage in this period, so you might also find a rare quadrant capable of 15" accuracy or a metal sextant engraved only to 30" accuracy. But 10" for sextants and 1' for quadrants would be typical.

    Frank Reed
    Conanicut Island USA

    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