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: Extremely poor conditions??
    From: Alexandre Eremenko
    Date: 2012 Mar 20, 21:32 -0400

    Thanks,
    I digged out my collection of papers about refraction.
    Wollaston and especially Huddart (same transactions, Nov 24, 1796)
    describe the cases of inverted refraction (when the ray is bent
    away from the earth).
    For Cel Nav, they advise taking direct and back sights, and average them,
    the thing not possible with modern sextants:-)
    They attribute the phenomenon to unusual concentrations of vapor in the
    atmosphere.
    
    Alex
    
    On Tue, 20 Mar 2012, Bill Morris wrote:
    
    >
    > Alex
    >
    > You wrote "I still have to dig the old archives on the anomalous refraction.
    > I even sort of remember reading a paper of Wollaston in
    > the Royal Soc. Proc. where he investigated this for the first time,
    > if I remember correctly."
    >
    > Wollaston's paper is here:
    >
    > http://www.jstor.org/stable/107055
    >
    > Bill Morris
    > Pukenui
    > 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
    > ----------------------------------------------------------------
    >
    >
    >
    >
    > View and reply to this message: http://fer3.com/arc/m2.aspx?i=118426
    >
    >
    >
    
    
    
    

       
    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