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seem smaller to him than the smallest star that
someone sees in the sky (see note), if that person is on the earth
looking up at it, whether he is on a mountain
or in a valley. And by this one may know how
quickly the sky moves in order for it to be able
to make a full circle around the earth by day and night.
We can see this when the sun
rises in the east in the morning and sets in the west.
And the next day at dawn we see it once again in the
east. For it completes a circle in what
is called a natural day, which comprises a day
and a night. In this way the sun comes and
goes without ever resting, nor will it stop from
going along with the sky. This is just like
a nail that is stuck in a wheel, which
turns when the wheel turns. But
I will give you another explanation why the sun moves opposite
to the turning of the firmament. If a fly traveled
along a turning wheel, if it was went in the opposite direction to
the wheel it would still be carried along with it.
But whereas the wheel would have turned
many times, the fly would have turned once,
and it would have gone