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: New Moon, Perigee, and Solstice
    From: George Huxtable
    Date: 2003 Dec 30, 14:21 +0000

    The delay, between the moment of New or Full Moon (or syzygy, a favourite
    word of mine) and the greatest range of tide near to it (spring tide), has
    had the name for many years "the age of the tide". Not a perfect name,
    perhaps, but if Frank Reed and Trevor Kenchington had both used it
    consistently, much misunderstanding would have been avoided.
    
    Frank said-
    
    >This all got started because I
    >pointed out that Bowditch wrote in early editions about Spring Tides
    >occurring three days AFTER New Moon/Full Moon. That rule applies
    >reasonably well in
    >parts of northwest Europe.
    
    I don't doubt that Bowditch made such a statement, though I don't have an
    early Bowditch to check. But on what basis does Frank justify his own
    claim, that Bowditch's three-day rule "applies reasonably well in parts of
    northwest Europe".  My own experience supports the statement in the
    Admiralty Manual of Tides "The average value of the age is about 1 to 1 1/2
    days", perhaps in some parts of Europe 2 days. I think that Cassini, who I
    quoted in an earlier mailing, got the age of the tide about right, at 1 day
    to the West of the English Channel, 2 days to the East.
    
    In an earlier mailing, Frank had said-
    
    >Northwest Europe has a
    >SPECIFIC phase lag that Bowditch copied from European sources (or maybe simply
    >"knew" from the common culture of European sea lore). The specific phase
    >lag for
    >Europe leads to a specific lag of the Spring Tides there. That phase
    >difference applies to much of northwest Europe, but it does not apply to
    >the Americas
    >generally.
    
    We know now that the phase-lag or phase difference Frank was referring to
    was the age of the tide. Now he is back-tracking somewhat by claiming only
    that "That rule applies reasonably well in parts of northwest Europe."
    
    Well, I simply ask Frank to supply some evidence to support his own claims
    about that three-day "age", on which he has built such a big argument. To
    which parts of northwest Europe does he claim that it applies? I am not
    claiming he is wrong; just asking for the evidence.
    
    George.
    
    ================================================================
    contact George Huxtable by email at george---.u-net.com, by phone at
    01865 820222 (from outside UK, +44 1865 820222), or by mail at 1 Sandy
    Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK.
    ================================================================
    
    
    

       
    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