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: Cable Time
    From: Fred Hebard
    Date: 2003 Mar 23, 22:28 -0500

    I apologize if I'm repeating myself.  But it seems to me there is a
    circular argument going on here.
    
    The navigators in the story very clearly were determining the error in
    their chronometers by land observations of sun or stars.  There would
    be no need to do so if accurate time could be transmitted by cable.  So
    one concludes that accurate time could not be transmitted by cable, or
    was not transmitted very often.  (To do so, one would need to establish
    accurate time at the transmitting station.  If that station were
    located near the shore, and relayed signals from Paris or London by
    land-borne telegraph, then I expect that accurate signals could not be
    propagated to the station by land-borne telegraph, due to the time
    delays introduced by relays along the way).
    
    It would seem to me to be much easier to determine time at the
    transmitting station by observing the moons of Jupiter or some such, in
    place.  This also could be done at each cable station to determine
    longitude accurately.  Once the longitude of a station were known, one
    could determine the error of one's chronometers as described.  As
    George Huxtable describes, simple triangulation from the level spot to
    the benchmark spot could determine the location of the level spot, if
    the location of the level spot differed from that of the benchmark
    spot, which it might not.
    
    
    

       
    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