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    Re: Size of a nautical mile
    From: Gary LaPook
    Date: 2009 Jan 15, 14:38 -0800

    Check your math, 90 X 60 = 5,400 not 7,200. But you obviously used
    5400 to get you result.
    It is interesting to remember that the meter was originally defined as
    one ten millionth the distance from the equator to the pole and they
    got it pretty close by measuring the meridian from Barcelona to
    Dunkerque, taking 7 years while the french revolution swirled about
    them. Using the original measure there would be 1851.85 meters in one
    minute of latitude. They are only off by about 2,000 meters, about 1
    NM in a distance of about 5,400 NM.
    On Jan 15, 1:35�pm, Lu Abel  wrote:
    > As has been pointed out, the length of a degree of latitude varies from
    > pole to equator.
    > The nautical mile is supposed to equal a degree of latitude. � Today,
    > however, it is defined as precisely 1852 meters.
    > When one multiplies 1852 by 7200 (the number of minutes in 90 degrees),
    > one gets 10 000 800 meters as an answer.
    > My understanding is that the distance from equator to pole is 10 002 000
    > meters. � It's a small discrepency, on the order of 0.01%, but I'm
    > wondering why it was allowed to stand instead of defining the NM more
    > precisely.
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