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    Re: Chronometer Suggestions
    From: George Huxtable
    Date: 2009 Jan 6, 14:57 -0000

    Bill Sellar asked-
    
    As a beginning celestial navigator, I am wondering how much time and watch 
    accuracy is actually required for practical navigation. Can we predict how 
    many miles off one would be for every second of time error?
    
    ==========================
    
    A fair question. Answer: a quarter of a minute of longitude, which 
    corresponds to a quarter of a mile in position-error at the equator, and 
    correspondingly less at highter latitudes. That corresponds to the rate at 
    which the Earth spins, 360� in 24 hours.
    
    The precision available from a chronometer ceased to be of any great 
    importance once radio timing signals became available. Bill |Sellar has to 
    realise that many denizens of this list share a quest for precision for its 
    own sake, rather than for the purposes of practical navigation: and who are 
    we to deny them their fun?
    
    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. 
    
    
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