Dear Hans,

Yes, Roderick Wall is right...

> ... it would work if all your sticks
> are parallel to the axis of the 
> earth.

You just need a whole set of polar-oriented
gnomons, BUT...

You have added an extra constraint...

> I would like the little gnomons to be
> perpendicular to the face of the dial...

No problem.  As Roderick almost says:

You simply arrange for the face of the dial
to be parallel to the plane of the Equator.

There is, though, a twist in all this...

We are assuming that you want this dial to
indicate local sun time.

If we relax that assumption, the face of
the dial can have almost any orientation.
You don't get sun time then.  You get what
Fabio Savian calls "Alignment Hours".

These are much more fun than boring old
sun hours and your design would illustrate
these hours very well.

The only snag is that no one would appreciate
your efforts except Fabio, you, me, readers
of this list, and anyone living in Paris!

Why Paris?

Well, the Arc de Triomphe, stands at the
centre of a major intersection with 12
streets meeting at the centre.

If you stand at the top you can see the
sun shining along each street in turn
while the sun is shining.  What you see
are Fabio's alignment hours.

Frank King
Cambridge, UK


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