You may, perhaps, exclaim: Are you then so benighted as to suppose that the gods send out previous intimation of the death of great men? Do you imagine that anything on earth is so great that the Universe should perceive its loss? That question must be reserved for another season. We shall then see whether a fixed succession is observed in all events, and whether one event is so bound up with another that what precedes is either cause or at least token of what follows. We shall then see, 4 too, whether the gods trouble themselves about human concerns, and whether the mere series of events reveals by unmistakable signs what its effects must be. Meantime, I venture the opinion that fires of the class referred to are produced by violent friction of the atmosphere. The pressure inclines toward one or other side, and as there is no yielding there, an internal struggle ensues. From violent action of this kind arise the different varieties of fires--beams, balls, torches, and gleams. When the shock is less severe, and the atmosphere is merely grazed, as it were, smaller lights are emitted, And the flying stars drag their hairy tail. Then their thin fires mark a slender path, which they prolong across 5 the sky. For that reason no night is without sights of the kind; no great movement of the atmosphere is required to produce them. In fact, to put it shortly, they are due to the very same cause as thunderbolts, only they require less force. Clouds that encounter each other with little force cause flashes of lightning; if impelled by greater violence, thunderbolts. Aristotle offers the following explanation: The earth gives forth many 6 different exhalations, some moist, some dry, some cold, some containing the seeds of fire. And little wonder if the earth’s evaporation is of all varied kinds. Why, even in the heavens the colour of objects does not show uniform; the red of the Dog-star is brighter, that of Mars duller; Jupiter has no red, his sheen is prolonged into pure light. 7 Well, in the great abundance of minute bodies emitted by the earth and driven up to the higher regions, of necessity some of the elements that reach the clouds furnish material for fires. They do not require any collision in order to burn, the breath of the sun’s rays is sufficient to kindle them. So with us, shavings sprinkled with sulphur catch fire at some distance. Probably, therefore, tinder of this kind gathering 8 within the clouds is easily kindled; greater or less fires are produced just as there has been more or less substance in the elements.