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
    or...
       
    Reply
    Re: Sextants, vernier and micrometer.
    From: George Huxtable
    Date: 2006 Oct 31, 10:13 -0000

    About the sextant arc that Alex pictured at
    
     http://www.math.purdue.edu/~eremenko/pic1.jpg
    
    Henry Halboth wrote-
    
    | It looks to me to be a 10 second vernier. Most older
    sextants/octants had
    | either 10 or 15 second reading verniers.
    
    But I think Henry should look again. It has 5 divisions to each minute
    of the Vernier arc, as I see it, which means that it measures to 12
    seconds, or 0.2 arc-minutes, somewhere between the two values that
    Henry suggested, of either 10 or 15 seconds.
    
    That has advantages when the arithmetic started to be done in decimals
    of a minute, rather than in seconds. Perhaps it dates the instrument
    to the later days of Vernier sextants.
    
    George.
    
    contact George Huxtable at george@huxtable.u-net.com
    or at +44 1865 820222 (from UK, 01865 820222)
    or at 1 Sandy Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK.
    
    
    --~--~---------~--~----~------------~-------~--~----~
    To post to this group, send email to NavList@fer3.com
    To unsubscribe, send email to NavList-unsubscribe@fer3.com
    -~----------~----~----~----~------~----~------~--~---
    
    

       
    Reply
    Browse Files

    Drop Files

    NavList

    What is NavList?

    Join NavList

    Name:
    (please, no nicknames or handles)
    Email:
    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:

    Email Settings

    Posting 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