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: Altitudes, close to 90
    From: Alexandre Eremenko
    Date: 2004 Dec 1, 00:38 -0500

    Dear Frank:
    
    On Wed, 1 Dec 2004, Frank Reed wrote:
    
    > But  actually the
    > sextant has to be swung about the line of sight to the  object.
    
    This Maskelyne also says (in the same paper).
    But then he continues:
    
    "...can be only produced by the quadrant being turned
    upon a line drawn from the eye to the Sun, as an axis;
    a motion of rotation upon this line may be resolved into
    two, one upon the axis of vision (he means the horizontal axis here)
    and the other upon the line on the quadrant perpendicular to the
    line of vision; and consequently a proper combination of these
    two motions will keep the Sun constantly in the axis of vision...
    etc."
    
    > you know the correct rule, then the second paragraph
    > is nothing more than a
    > special case of it since rotating the sextant about a
    >  vertical line means
    > spinning about on your heels.
    
    And this he also says, almost in the same words.
    
    Alex.
    
    
    

       
    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