730 Ulisse Aldrovandi

...mounds composed of opaque light, with some stars flickering within, can be seen. Moreover, a certain cluster of stars is observed below the last part of Orion’s belt, where they are gathered in a small space; then, among these little stars, a white light shines like a cloud. Further on, a little above the arrow of Sagittarius, a dark globe also appears among the mixed stars.

Furthermore, one may conjecture that wandering corpuscles are found in the heavens from certain sunspots that many have observed with an excellent telescope. Therefore, if these or other bright corpuscles—which are not individually visible—flow together into one, they shine out, just as if a planet were to join with another planet or a fixed star. In such a case, the rays of both are so blended that they appear to be the brightness of only a single star. For this reason, once these are so arranged, comets are said to vanish when these corpuscles, which had previously gathered, scatter again. Since these corpuscles are small and filled with a somewhat diffused light, they cannot equal the splendor and clarity of other stars. Thus, many have most diligently observed through optical tubes that comets are composed of these corpuscles.

The "hair" and tail of comets are not fire, nor a burning mass, but perhaps the transmission of the Sun’s rays in that shape through these loosely united corpuscles, in the same way that sunbeams are sent through a hole into a room. Moreover, the reflection and refraction emanating from various corpuscles can account for the different forms of comets: long-haired, bearded, and tailed.

Many authors affirm that the appearance of comets foretells disasters for the world. Thus, in the tenth book of the *Aeneid*, Virgil compares the weapons of Aeneas—which he had received through the generosity of Vulcan—to comets and Sirius (the Dog Star), because they were forged for the destruction of many. The appearance of these stars results in illness and the death of men. Virgil's words are these:

"Just as when in the clear night blood-red comets glow mournfully, or the burning Sirius, which brings thirst and disease to weary mortals, rises and saddens the sky with its ill-omened light."

For this reason, they report that the Actaeans were most diligent in observing the rising of the Dog Star, as witnessed by Pierio; for from its appearance, they understood whether the coming year would be healthy or pestilential. Indeed, if this star appeared dim and foggy, they would foretell that the air was thick and stagnant, and consequently that the year would be oppressive and diseased. But if it appeared bright and clear, they predicted that the sky would be pure and the year healthy.

If the Dog Star can bring so many great evils to the human race, we can, according to Pliny, expect much more from comets; for they are said to portend wars, famine, disasters, diseases, the overthrow of cities, changes of kingdoms, the death of men, and various forms of destruction. Therefore, it was not without reason that the old Greek adage of an unknown author was coined: "The comet is a star that brings evil," which a certain scholar quite gracefully rendered into hexameters as: "Alas, a comet is never seen without certain disaster." Closely agreeing with this is the line from Claudian: "And never was a comet seen by the lands without a price."

Tacitus also has this to say in his *Annals*: "A comet shone forth, about which there is a common opinion that it portends a change in kingdoms." Similarly, Silius Italicus sang of the matter:

"As the comet terrifies fierce kingdoms with its flaming hair, scattering blood-red fire, the dark torch vomits rays across the reddening sky, and the star sparkles, glittering with a savage light, threatening the earth with the end of all things."

There is indeed a persistent opinion among men that the appearance of a comet denotes the death of princes. Suetonius testifies to this in his life of Nero: "A long-haired star, which is commonly thought to portend destruction for the highest powers." He recorded the same regarding Claudius: "The chief omens of his death were the rising of a long-haired star, which they call a comet." But there was a witty remark recorded in the history of Vespasian; for when a long-haired star appeared...