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: Off Center Sextant Scope Observations
    From: Fred Hebard
    Date: 2007 Nov 26, 17:19 -0500

    I'll take a look George.
    
    On Nov 24, 2007, at 5:14 PM, George Huxtable wrote:
    
    >
    > Fred Hebard wrote-
    >
    > | As I recall when determining index error using the sun, the point of
    > | contact varies with up and down location in the telescope.
    >
    > ==================
    >
    > Response from George.
    >
    > How interesting! When Fred says "As I recall ...", is he going just
    > by a dim
    > recollection, or is it a real, reproducible effect, that he can see
    > whenever
    > he tries to repeat it? To me, it appears to defeat the laws of
    > optics as I
    > understand them, but that doesn't lead me to deny that Fred saw
    > what he saw.
    > It  makes it worth examining more closely to discover why.  Could
    > it result,
    > perhaps, from a mirror that wasn't exactly flat, so the reflection
    > angle
    > varies slightly when you use a different part? Or a shade with a
    > bit of
    > ripple in it? Tell us more, Fred.
    >
    > 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.
    >
    >
    > >
    
    
    
    --~--~---------~--~----~------------~-------~--~----~
    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