CHAPTER II. OF COMETS AND SHOOTING FIRES, AND THOSE WHICH RESEMBLE BEAMS.
Some of the Pythagoreans say, that a comet is one of those stars which do not always appear, but after they have run through their determined course, they then rise and are visible to us. Others, that it is the reflection of our sight upon the sun, which gives the resemblance of comets much after the same manner as images are reflected in mirrors. Anaxagoras and Democritus, that two or more stars being in conjunction by their united light make a comet. Aristotle, that it is a fiery coalition of dry exhalations. Strato, that it is the light of the star darting through a thick cloud that hath invested it; this is seen in light shining through lanterns. Heraclides, native of Pontus, that it is a lofty cloud inflamed by a sublime fire. The like causes he assigns to the bearded comet, to those circles that are seen about the sun or stars, or those meteors which resemble pillars or beams, and all others which are of this kind. This way unanimously go all the Peripatetics, holding that these meteors, being formed by the clouds, do differ according to their various configurations. Epigenes, that a comet arises from a rising of spirit or wind, mixed with an earthy substance and set on fire. Boethus, that it is a phantasy presented to us by fiery air. Diogenes, that comets are stars. Anaxagoras, that those styled shooting stars descend from the aether like sparks, and therefore are soon extinguished. Metrodorus, that it is a forcible illapse of the sun upon clouds which makes them to sparkle as fire. Xenophanes, that all such fiery meteors are nothing else but the conglomeration of the enfired clouds, and the flashing motions of them.
CHAPTER III. OF VIOLENT ERUPTION OF FIRE OUT OF THE CLOUDS. OF LIGHTNING. OF THUNDER. OF HURRICANES. OF WHIRLWINDS.
Anaximander affirms that all these are produced by the wind after this manner: the wind being enclosed by condensed clouds, on account of its minuteness and lightness violently endeavors to make a passage; and in breaking through the cloud gives noise; and the tearing the cloud, because of the blackness of it, gives a resplendent flame. Metrodorus, that when the wind falls upon a cloud whose densing firmly compacts it, by breaking the cloud it causeth a great noise, and by striking and rending the cloud it gives the flame; and in the swiftness of its motion, the sun imparting heat to it, it throws out the bolt. The weak declining of the thunderbolt ends in a violent tempest. Anaxagoras, that when heat and cold meet and are mixed together (that is, ethereal parts with airy), thereby a great noise of thunder is produced, and the color observed against the blackness of the cloud occasions the flashing of fire; the full and great splendor is lightning, the more enlarged and embodied fire becomes a whirlwind, the cloudiness of it gives the hurricane. The Stoics, that thunder is the clashing of clouds one upon another, the flash of lightning is their fiery inflammation; their more rapid splendor is the thunderbolt, the faint and weak the whirlwind. Aristotle, that all these proceed from dry exhalations, which, if they meet with moist vapors, forcing their passage, the breaking of them gives the noise of thunder; they, being very dry, take fire and make lightning; tempests and hurricanes arise from the plenitude of matter which each draw to themselves, the hotter parts attracted make the whirlwinds, the duller the tempests.