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
    Name or NavList Code:
    Email:
       
    Reply
    Re: Beginner
    From: Herbert Prinz
    Date: 2005 Sep 18, 19:02 -0400

    Espen S. Ore wrote:
    
    > But it is in certain places along the scale easier to do fine
    > adjustments one way than another.
    
    True. But there is no way telling in advance in which direction the arm
    slides easier the next time from a given position.  Inherent in the
    simple adjustment mechanism of the Mark 3 (or rather absence thereof) is
    a physical problem: initial friction at rest is higher than the sliding
    friction while moving. This creates a tendency to overshoot. The best
    answer is your own solution:
    
    > Actually the most precice measurments are probably when the sextant is
    > set a
    > little to high or low (depending on the time) and then kept until the
    > sun moves up or down to that height.
    
    Of course, you don't have this option for establishing the index error.
    But there you have more time to play until you get it right.
    
    Still, once you have managed to _set_ the Mark 3 to the correct angle,
    be it through presetting it in the way you describe, dexterity, or good
    luck you can trust the reading regardless which way you set it. That is
    different from a drum sextant, where the angle to be measured should be
    set approaching from the same side as when index error was established.
    
    Herbert Prinz
    
    
    

       
    Reply
    Browse Files

    Drop Files

    NavList

    What is NavList?

    Get a NavList ID Code

    Name:
    (please, no nicknames or handles)
    Email:
    Do you want to receive all group messages by email?
    Yes No

    A NavList ID Code guarantees your identity in NavList posts and allows faster posting of messages.

    Retrieve a NavList ID Code

    Enter the email address associated with your NavList messages. Your NavList code will be emailed to you immediately.
    Email:

    Email Settings

    NavList ID 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