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: chronometer dials: 12 or 24 hours?
    From: George Huxtable
    Date: 2009 Jan 19, 20:20 -0000

    The attached picture should answer Clive's worry about the difficulty of
    reading a 24-hour clock. This clock has stood at a gate of the Royal
    Observatory, Greenwich, for over 150 years. It's actually an early electric
    "repeater" from a master clock.
    
    In my view, the only problem about reading it is in the multiplicity of Is,
    Vs, and Xs that are called for by the use of Roman numerals. If ordinary
    numerals had been used, it would have been much clearer.
    
    It relates, a bit, to earlier discussion, in that the moment of passing 24
    hours must have been changed, at some date, from midday to midnight.
    Probably when Greenwich time changed, at the start of 1924.
    
    Note that at the very top mark, the dial is not labelled XXIV (=24), but 0,
    something that all our 12-hour dials could usefully follow.
    
    George.
    
    contact George Huxtable, at  george{at}hux.me.uk
    or at +44 1865 820222 (from UK, 01865 820222)
    or at 1 Sandy Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK.
    
    
    --~--~---------~--~----~------------~-------~--~----~
    Navigation List archive: www.fer3.com/arc
    To post, email NavList@fer3.com
    To unsubscribe, email 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