In 1822, the ashes for twelve days fell in a continuous shower. The lava which had boiled up and hardened till the appearance of a depressed crater was lost was blown away. An immense abyss was formed, three-fourths of a mile in length and two thousand feet deep. The entire top of the cone was then blown away. Masses of lava weighing many tons were hurled two or three miles. Darkness prevailed in broad day, as far away as Amalfi, where the ashes fell to the depth of several inches. The dense column of ashes and vapor was thrown ten thousand feet above the level of the sea. In no known eruption has the electrical display been so brilliant and continuous. The roll of thunder could be clearly distinguished from the rumble of the volcano. In recent years an observatory has been erected on the mountain, and all its phenomena carefully noted. During the eruption of 1872 instantaneous photography was pressed into service. A comparison of the whole view with the height of the mountain, showed that the vapors and fragments were thrown twenty thousand feet into the air--nearly four miles. This outburst began on April 24, and reached its climax in two days. The entire mountain filled with fissures and cracks--in the words of Prof. Palmieri, “sweated fire.” Enormous volumes of steam poured from the crater, with such a prodigious roar, that the terrified Neapolitans rushed from their houses, and spent the night in the open air. The lava floods rushed down the mountain side; and one of them destroyed two villages, besides many country houses adjacent. The whole region for several days quivered with shocks of earthquake. Such have been the more important eruptions of Vesuvius. Its position, by an ancient and populous city, has made it the most celebrated of volcanoes. There seems no doubt that it is supplied from the same source which feeds the others in the neighborhood, as well as Mt. Ætna. When Vesuvius is quiet, Ætna is active, and vice versa. Close observation has established a well-defined daily periodicity: so that the most favorable period for visiting the crater may always be known beforehand. In fine, about sixty eruptions of Vesuvius are on record. Of these, twenty-three were during the last century, and twenty-five during this. The activity of the entire region seems on the increase. CHAPTER XXII. OTHER GREAT ERUPTIONS. “Hast thou observed the ancient tract, That was trodden by wicked mortals, Who were arrested on a sudden, Whose foundation is a molten flood? Who said to God, Depart from us, What can Shaddai do to us? Though he had filled their houses with wealth. (Far from me be the counsel of the wicked!) The righteous beheld and rejoiced, The innocent laughed them to scorn, Surely their substance was carried away, And their riches devoured by fire.”