Element of fire. — Middle region of the air. The water interposed between the fire and the water partakes of water and of fire, but so much more of the one than of the other as it is nearer to the one than to the other. It follows that it partakes so much less of each as it is more remote from them; and this remoteness lies in the middle of the region of the air. Therefore this middle region is in the first degree of coldness. For this reason it follows that the part of the cloud that comes closest to this middle region cools the most. Whence the heat of the sphere of fire, drawn up by such a cloud, is of lesser power, and for this reason it follows that the motions of the moist granules that compose the clouds are of slower motion. And therefore it follows that in the rising of the granules of moisture, that which rises higher toward the vicinity of this middle region is more delayed, and that which follows it is faster than it, so that it overtakes it; and it often happens that it strikes it from below and becomes incorporated in it and increases its quantity and weight. And for this reason the air, being unable to sustain it, gives place to its descent, which strikes all the droplets that impede its motion, and incorporates many of them into itself, and, gaining weight, gains speed of descent. Wherefore, once it has penetrated its whole cloud, at every degree of descent it will acquire degrees of diminution, and many will be the times that such granules will not reach the ground. But if such granules, in the topmost part of their height, acquire so much weight that the weight generates a swift descent for them, without doubt this motion will increase their size, since this speed will overtake the droplets that descend below them and will incorporate them into itself; and this will be the increase of weight at every degree of its descent.

a b c d fe. The descent of droplets that strike one another without wind will not be straight, but will be angled. It is proved, because if two bodies strike one another in the air, that one will be moved further out of its straight line which is of lesser quantity. And if two different grains of dew or of quicksilver join together, both the one and the other will be moved from their place, and the proportion of their motions will be similar to that of their magnitudes.

Liquid varnish. The droplet of that liquid will be of more perfect sphericity, which will be of lesser [size] ... For why is it that, if two spherical liquids of unequal quantity come to the point of contact between them, the larger draws the smaller to itself and immediately incorporates it without destroying the perfection of its sphericity? This is a difficult answer, but for this I would not refrain from giving my opinion. Water clothed by air naturally desires to remain united in its sphere, because in such a state it is deprived of weight. This weight is double, that is, its whole has weight directed toward the center of the elements, and the second weight is directed toward the center of its own watery sphericity; and if this were not so, it would make of itself only a half-sphere, which is the part that lies from the center upward. But of this I see no way in the human mind to give knowledge; rather I would say, as it is said of the lodestone that draws iron, that such a power is an occult property, of which there are infinite ones in nature. But we shall ask why there is more perfection in the smallest sphere of the liquid than in the large one. Here it is answered that the smallest droplet has a lightness more similar to the air that surrounds it than the large droplet has, and, because of the small difference, it is more sustained from the middle downward by that air than the large one. And in proof of this one may cite the smallest droplets, which are of so small a figure that they are almost invisible in themselves, but many in quantity are visible: and these are the little particles that compose the clouds and the mists. This is because the air that submerges rises enclosed in a garment of water, which settles on its surface in the figure of a half-sphere; and if it is viscous water, it moves through the air in a spherical figure.

Rattle, or bladder of water. You shall make experiment of these water rattles [bubbles], which, upon a little water placed in a basin, make, by means of the solar rays, cruciform images upon the bottom of that basin.