Meteorology

For on this view it is certain amounts of each that are equal in power, just as would be the case if they actually originated from one another.

So it is clear that neither air nor fire alone fills the intermediate space.

It remains to explain, after a preliminary discussion of
difficulties, the relation of the two elements air and fire to
the position of the first element, and the reason why the 20

stars in the upper region impart heat to the earth and its
neighbourhood. Let us first treat of the air, as we proposed, and then go on to these questions.

Since water is generated from air, and air from water,
why are clouds not formed in the upper air? They ought 25

to form there the more, the further from the earth and the
colder that region is. For it is neither appreciably near to
the heat of the stars, nor to the rays reflected from the
earth. It is these that dissolve any formation by their 30

heat and so prevent clouds from forming near the earth.
For clouds gather at the point where the reflected rays