So, imagine that the gnomon IS that axis, and imagine a plane tangent (=touching) the earth in the North Pole, divided in 24 equal angles.
Well, with some approximation, it should be clear that the shadow of the axis runs around, covering one of these angles in exactly an hour.


I was about to ask how you could read it at night to prove that it works for each hour. But, of course, you'd be able to use a torch to see, wouldn't you? [running-like-hell emoticon]



The idiot also known as Capfka ...