Chapter Iv. of Clouds, Rain, Snow, and Hail.

Anaximenes thinks that the air by being very much condensed clouds are formed; this air being more compacted, rain is compressed through it; when water in its falling down freezeth, then snow is generated; when it is encompassed with a moist air, it is hail. Metrodorus, that a cloud is composed of a watery exhalation carried into a higher place. Epicurus, that they are made of vapors; and that hail and snow are formed in a round figure, being in their long descent pressed upon by the circumambient air.