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: Finding longitude in the 12th century
    From: Alexandre Eremenko
    Date: 2012 Sep 1, 06:16 -0700

    On my opinion, there was NO way of finding longitude in 12-th century,
    except by dead reconing or measuring distance on land.
    Theoretically, one could time the eclipses, simultaneously
    at two different places but there was really no way
    to time them in 12-th century with sufficient precision.

    The proof of this is that actually longitides of many places were found
    incorrectly, until the invention of modern methods, like Jupiter

    It is also practically impossible to find longitude from stars only
    (without a chronometer, Moon or Jupiter satellites). I remember Frank
    proposed once using some varibale star with appropriate period, but
    I strongly doubt that this could be used in 12-th century, or that
    it was ever used by the US Navy.

    So probably the sailor, who participated in the war in Pacific,
    just forgot to mention that except the tables, chronometer should be used.


    NavList message boards and member settings: www.fer3.com/NavList
    Members may optionally receive posts by email.
    To cancel email delivery, send a message to NoMail[at]fer3.com

    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