Fellow Shadow Watchers,
Information boards are being prepared for a
nearly-completed large dial on a hill near the Northumberland (UK) coast which
is 94 metres above mean sea level at Latitude 55° 1' 38" North Longitude 1°
30' 16" West.
The latest question is "How far away is the sea horizon?" School geography
taught me that the earth is an 'oblate speroid' so I suppose the true distance
varies slightly depending on the direction in which the observer is looking but
so little as to be unimportant perhaps? The sea is only visible in a generally
easterly direction.
Can any list member supply the mean sea level radius of the earth at this
location on which to base the necessary trig calculation plus any subtleties I
may have overlooked as I don't have ready access to specialist reference
material of this sort.
With thanks in anticipation of any helpful response.
Tony Moss
