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    Re: leap seconds a navigational hazard, says expert
    From: Richard M Pisko
    Date: 2003 Aug 10, 20:08 -0600

    On Sat, 9 Aug 2003 22:52:32 -0700, Brooke Clarke wrote:
    
    >I did not file down the tacks.  The heads are a little less than 1/8"
    >diameter and were seated so only a tiny fraction of an inch was sticking
    >up.  You can feel the head with you fingers.  No problem to walk on them
    >bare foot.
    >
    That was my first thought; yes.  I'm glad it's not a problem, and I
    read the description so it seems as though it would be rather nice.  I
    couldn't quite make out the drawings on your ... calculations, I think
    it was.
    
    >>>I made one of these by placing a metal plate at the lower end of a South
    >>>facing skylight and using a 3x5 card with a number of concentric
    >>>ellipses and a small hole at their center.  I just tracked the Sun's
    >>>image with the card and at exactly noon stopped and drive a small brad
    >>>nail into the hardwood floor.  After many years there would be more than
    >>>one nail for the same date because as we go through the 4 years of the
    >>>leap year cycle the timing is a little different.
    >
    I see the reasoning behind the series of ellipses on the (much
    handled) 3x5 card; to more closely match the sun's shape on the
    horizontal floor.  What are the rough dimensions of your analem...
    figure "8"?
    
    I guess I could calculate that, given the difference in elevation
    between the skylight aperture and the floor, as well as your latitude,
    but I thought a reality check might be a break from the theory.  :-)
    
    
    --
    Richard ...
    
    
    

       
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