Greetings fellow dialists,
First I take and accept the point of Andrew James. Mea culpa. Now to the
solution of the compass point problem. Fortunately Tony Moss has just
visited me and agreed it. In one of the four photos I took I have now
been able to see two small holes drilled in the gnomon.  These are
clearly for the reception of a removable vertical rod arising over the
centre point. Thus the shadow of this rod would give the sun's bearing
plus 16 points (180 degrees) Moreover, by listing the reciprocal the
sun's actual bearing is recorded directly. And one eighth of a point is
only about 1.4 degrees so considerable accuracy is possible.

By the way, old nautical tables offered trigonometric solutions in
(usually 1/4) points, e.g. with traverse tables which are solutions of
right angled triangles and used in plane sailing.
Frank 55N 1W
-- 
Frank Evans
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