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: Jupiter's moons
    From: Herbert Prinz
    Date: 2002 Mar 21, 00:51 +0000

    I believe this is a misunderstanding. Sighting pieces differ mainly in
    magnification, field of view and light power or whether the image was erect or
    inverted depending on whether they were optimized for observing the Sun or the
    stars, on a steady deck or in a seaway, or for altitudes or distances. None
    were suitable for Jupiter satellite observation. Why would one want to observe
    satellite phenomena with a sextant, anyway? It's difficult enough with a
    suitable telescope. Try to watch (never mind timing!) Jupiter's satellites with
    your regular binoculars, and you will see what I mean. Sighting pieces are and
    were certainly not better than modern binoculars.
    By the way, does Riddle really say "occultations" ? He sure means "eclipses",
    doesn't he?
    Nigel_Gardner wrote:
    > Herbert wrote  magnification do/did
    > these sighting pieces have?>
    > I am afraid I have not, in UK decent old sextants have been priced out of
    > navigators' markets by being bought up by chi-chi antique dealers to sell
    > to people to hang on a wall.  My own 'good' sextant is a modern Zeiss but
    > with only one eyepiece.
    > I looked in my copies of Nories Epitome (one 1805 and the other 1896) which
    > give good, long and lucid descriptions of sextants. Both descriptions say
    > that a sextant is normally equipped with two magnifying eyepieces of
    > different strengths but neither sadly give any indication of what the
    > stengths are.
    > NG

    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