In proportion as the blackness gathered did the lightnings around Vesuvius increase in their vivid and scorching glare. Nor was their horrible beauty confined to the usual hues of fire; no rainbow ever rivalled their varying and prodigal dyes. Now brightly blue as the most azure depth of a southern sky--now of a livid and snakelike green, darting restlessly to and fro as the folds of an enormous serpent--now of a lurid and intolerable crimson, gushing forth through the columns of smoke, far and wide, and lighting up the whole city from arch to arch--then suddenly dying into a sickly paleness, like the ghost of their own life! In the pauses of the showers you heard the rumbling of the earth beneath and the groaning waves of the tortured sea; or, lower still, and audible but to the watch of intensest fear, the grinding and hissing murmur of the escaping gases through the chasms of the distant mountain. Sometimes the cloud appeared to break from its solid mass, and, by the lightning, to assume quaint and vast mimicries of human or of monster shapes, striding across the gloom, hurtling one upon the other, and vanishing swiftly into the turbulent abyss of shade; so that to the eyes and fancies of the affrighted wanderers the unsubstantial vapors were as the bodily forms of gigantic foes--the agents of terror and of death. The ashes in many places were already knee-deep; and the boiling showers which came from the steaming breath of the volcano forced their way into the houses, bearing with them a strong and suffocating vapor. In some places immense fragments of rock, hurled upon the house roofs, bore down along the streets masses of confused ruin, which yet more and more, with every hour, obstructed the way; and, as the day advanced, the motion of the earth was more sensibly felt--the footing seemed to slide and creep--nor could chariot or litter be kept steady, even on the most level ground. Sometimes the huger stones, striking against each other as they fell, broke into countless fragments, emitting sparks of fire, which caught whatever was combustible within their reach; and along the plains beyond the city the darkness was now terribly relieved, for several houses, and even vineyards, had been set on flames; and at various intervals the fires rose sullenly and fiercely against the solid gloom. To add to this partial relief of the darkness, the citizens had, here and there, in the more public places, as the porticoes of temples and the entrances to the forum, endeavored to place rows of torches; but these rarely continued long; the showers and the winds extinguished them, and the sudden darkness into which their sudden birth was converted had something in it doubly terrible and doubly impressing on the impotence of human hopes, the lesson of despair.