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    Re: Great Circle Course via calculator & HO 208
    From: Bill B
    Date: 2016 Oct 4, 23:12 -0400

    On 10/4/2016 2:13 PM, David Fleming wrote:
    > Appologies to Gary and all Navlist members my previous reply was too
    > terse and further should have been directed to Bill B.
    > Google Earth claims1 degree longitude at 41 N represents .76 degree arc.
    >  This is correct.
    > GE also says the arc is 45.46 nm long.  therefore 45.46nm / 60 nm/degree
    > = .7576 degrees.
    Perhaps semantics.
    To the best of my knowledge there are 360 degrees in a circle, 60
    minutes per degree, and 60 seconds per minute.
    Short answer, 86 degrees - 85 degrees = 1 degree, period.
    I suspect you are comparing apples to oranges. Certainly the distance in
    miles, meters feet etc. between meridians diminishes as the position
    moves from the equator to the poles, but a circle created by a parallel
    is still a circle (albeit with a smaller radius) and  degree remains a
    degree (as do arc minutes and arc seconds relationship to a degree).
    How then should I report my position on the 41st parallel half way
    between the 85th and 86th meridian? As 85d 22' 44" given your assertion
    that a degree is "45.46nm / 60 nm/degree = .7576 degrees" which equals
    45'27". (45' 27"/2 = 22' 44").
    I would prefer to report my longitude as 85d 30', especially if in need
    of rescue (perhaps lost in a sweetcorn maze?)! Less terse, but IMHO a
    superior answer if you want a chopper to show up with boiling water and
    butter :-)

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