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    Re: suggestion for a satisfactory celnav narrative
    From: George Huxtable
    Date: 2005 Jun 4, 16:31 +0100

    There are some strange comments in Peter Fogg's posting.
    
    Referring to latitudes in which the Sun approaches the zenith, he comments
    that the practical difficulties "mean that noon sights in such places may
    be notable by their absence".
    
    And yet, the whole recorded history of navigation tells us that whenever
    the sky was clear at noon, taking an altitude of the Sun was an inflexible
    rule for any vessel, whether in the tropics or not, in spite of those
    practical difficulties that Peter refers to. Perhaps those navigators were
    made of sterner stuff than he is. Does he have any evidence to show that
    noon sights were ever skimped or avoided in the tropics? I doubt it.
    "Notable by their absence"? Nonsense.
    
    And he adds the curious comment "plus the awkward contortions of trying to
    take a sight of the blazing Sun with the head tilted back at 90 degrees to
    the body." It makes me wonder if Peter himself has ever taken a sextant
    sight of the high Sun he refers to (I haven't). The process involves
    bringing the Sun down to the horizon, not vice versa, so there's no need to
    look up, at all. What IS he talking about?
    
    Bill suggested that there was some value in discussing "longitude by noon
    Sun", if only to point out why it a bad idea.
    
    To which Peter replied, even more curiously-
    
    "Nah, it's all grist to the mill. There's nothing good or bad, as
    Shakespeare said, only thinking makes it so... If it serves a useful
    function (at least when it comes to nav) then its all good. Not perfect,
    mind. Good is simply good."
    
    Well Shakespeare is hardly a relevant authority to call in aid on such a
    question. The problem about a navigator learning such a bad and inaccurate
    way of determining longitude is that it displaces from his mind the right
    way to do the job.
    
    George.
    
    ================================================================
    contact George Huxtable by email at george@huxtable.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.
    ================================================================
    
    
    

       
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