Note 381 — SECOND PART. The Astronomy of Dante. (continued 2)
Reading edition
“Vapours enkindled saw I ne’er so swiftly At early nightfall cleave the air serene, Nor, at the set of sun, the clouds of August, But upward they returned in briefer time, And on arriving with the others, wheeled Towards us.” Purg. v. 37-41. (Longfellow).
(By “vapours that cleave the clouds of August,” flashes of lightning without thunder are meant. Aristotle believed both these and meteorites to be ignited vapours).