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    Re: Pear shaped Earth
    From: Peter Fogg
    Date: 2002 Oct 3, 07:33 +1000

    David Weilacher wrote:
    > My conclusion from this is that a pear shaped earth has a negligible effect on
    > the accuracy of sight reduction.  It doesn't matter what distance you are from
    > the center of the earth (well there is an over-simplification) as long as the
    > horizon is also at the same level.  Since the horizon is likely to be only 4
    > to 10 nm away, this pear shape notion becomes moot because you and the horizon
    > are at the same height.
    Agree with this.
    > so, if I've understood correctly, a degree at
    > 10d of lat.is 59.71 nm, and a
    > degree at 90d of lat. is 60.007 nm.
    Woke up in the middle of the night, an attack of logic: if the earth bulges out
    at the equator and is flattened at the poles, then shouldn't a degree, expressed
    as nm, be longer at the equator and shorter at the pole?

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