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: Mid XIX century Nav
    From: George Huxtable
    Date: 2005 Nov 23, 15:40 -0000

    Frank Reed had written-
    
    If we don't trust the tabulated longitude, you have other options  for
    determining longitude ashore like moon culminations that are generally more
    accurate than lunars. These depend on a careful determination of true
    azimuth.
    
    to which I had objected
    > "But I'm not so convinced  about the practicality, for a ship's navigator,
    > of
    > timing Moon  culminations"
    
    And Frank now says-
    
    > I agree. I wouldn't expect any ordinary navigator in the  19th century to
    > do
    > anything like this. Rather, I would expect a typical  navigator with a
    > chronometer to test it by ordinary time sights from the first  port with a
    > trusted
    > longitude, perhaps supplemented by occasional lunars while  in regions
    > with
    > uncertain longitudes. But, if this was putatively a voyage of
    > "exploration" (as
    > it seems to have been, at least in theory), then I would  expect you might
    > have
    > an observer with greater astronomical skill.
    
    It seems we agree, then,  that a ship's navigator would not be determining
    his time that way, although we disagree about why. Frank presumes that a
    ship's navigator would not have the skill to do so, which may well be the
    case. However, even if he had that skill, he would not have had any
    instruments to allow him to make the "careful determination of the azimuth"
    that would be necessary. An astronomer or surveyor may have carried such
    instruments, but not a ship's navigator.
    
    George.
    
    contact George Huxtable at george---.u-net.com
    or at +44 1865 820222 (from UK, 01865 820222)
    or at 1 Sandy Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK.
    
    
    

       
    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