Welcome to the NavList Message Boards.


A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding

Compose Your Message

Add Images & Files
    Re: Perpendicularity check
    From: Alexandre Eremenko
    Date: 2004 Sep 22, 19:14 -0500

    Dear Fred,
    Thanks for your prompt reply to some of my questions.
    1. Bowditch (the online version I have) says the same as
    the authors of other sextant books I read; this does not
    address my question. Same about Bruce Bauer (which I have).
    > Until you get an almanac,
    > tAhe US Naval Observatory has a very nice
    > site
    > at  from which you can obtain
    Great!! Thanks! If I knew this earlier, I would not
    spend money on a 2004 Almanach.
    (Next time I will be sailing will be definitely not earlier than next
    summer. And until then I can use this wonderful web site
    for my "balcony
    > The old inverting telescopes had one nice feature for
    > observing lunars,
    > which was a cross hair reticule.
    When I said that my Soviet inverting scope is of poor quality
    I did not specify the details (being afraid that my message
    is too long anyway, and may be non-interesting for most
    because of the abundance of detasils). One point about
    this scope is that you
    cannot focus simultaneously on the cross hair and a remote object.
    And this is a constructive defect, not of this particular scope.
    > My understanding is that observed lunar distances will be too
    > large if
    > the sextant is not properly oriented.
    I don't understand this argument. I don't understand
    how cross hair are going to help. It seems to me
    that the usual "rocking" procedure will do the job.
    But I have not tried the lunar distances yet.
    I tried star distances (as described in Bruce Bauer for
    testing a used sextant).
    The distance Arcturus-Dubhe seems to indicate that my sextant
    error is at most) 0.3'.

    Browse Files

    Drop Files


    What is NavList?

    Join NavList

    (please, no nicknames or handles)
    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 Settings

    Posting Code:

    Custom Index

    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