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it would appear small, but of a radiance almost like the sun; --[5]
It must now be shown whether the moon is a heavy or a light body:
for, if it were a heavy body--admitting that at every grade of
distance from the earth greater levity must prevail, so that water
is lighter than the earth, and air than water, and fire than air and
so on successively--it would seem that if the moon had density as it
really has, it would have weight, and having weight, that it could
not be sustained in the space where it is, and consequently that it
would fall towards the centre of the universe and become united to
the earth; or if not the moon itself, at least its waters would fall
away and be lost from it, and descend towards the centre, leaving
the moon without any and so devoid of lustre. But as this does not
happen, as might in reason be expected, it is a manifest sign that
the moon is surrounded by its own elements: that is to say water,
air and fire; and thus is, of itself and by itself, suspended in
that part of space, as our earth with its element is in this part of
space; and that heavy bodies act in the midst of its elements just
as other heavy bodies do in ours [Footnote 15: This passage would
certainly seem to establish Leonardo's claim to be regarded as the
original discoverer of the cause of the ashy colour of the new moon
(lumen cinereum). His observations however, having hitherto
remained unknown to astronomers, Moestlin and Kepler have been
credited with the discoveries which they made independently a
century later.
Some disconnected notes treat of the same subject in MS. C. A. 239b;
739
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