Two other states on the northern extremity of the island were so far devastated by the Tambora eruption of 1815 that their territory, after lying for long uninhabited, was in 1866 divided between Dompo and Sangar.
In a serious eruption in 1856 .the S.E.
Above sea-level (in June 1900, 4275 ft., but after the eruption of 1906 considerably less).
The lagoon is slowly filling up and becoming cultivable land, but the rate of recovery from the sea has been specially marked since the eruption of Krakatoa, the pumice from which was washed on to it in enormous quantity, so that the lagoon advanced its shores from 20 to 30 yards.
Poas (8895), the scene of a violent eruption in 1834, begins a fresh series of igneous peaks, some with flooded craters, some with a constant escape of smoke and vapour.
This eminence is itself due to an outflow of lava from that mountain, during some previous eruption in prehistoric times, for we know from Strabo that Vesuvius had been quiescent ever since the first records of the Greek settlements in this part of Italy.
In the eruptions of 1823, 1832, 1840 and 1868 the floor of the crater rose on the eve of an eruption and then sank, sometimes hundreds of feet, with the discharge of lava; but since 1868 (in 1879, 1886, 1891, 1894 and 1907; and once, before 1868, in 1855) this action has been confined to Halemaumau and such other pits as at the time existed.
Formerly, on the eve of a great eruption of Mauna Loa, this crater often spouted forth great columns of flame and emitted clouds of vapour, but in modern times this action has usually been followed by a fracture of the mountain side from the summit down to a point moo ft.
Early childish adventures, as told by Arago, herald the fearless aeronaut and the undaunted investigator of volcanic eruptions (Vesuvius was in full eruption when he visited it during his tour in 1805); and the endurance he exhibited under the laboratory accidents that befell him shows the power of will with which he would face the prospect of becoming blind and useless for the prosecution of the science which was his very life, and of which he was one of the most distinguished ornaments.
The Elder Pliny inspired his nephew with something of his own indomitable industry; and in August 79, when the author of the Historia naturalis lost his life in the famous eruption of Vesuvius, it was the sister of the Elder and the mother of the Younger Pliny who first descried the signs of the approaching visitation, and, some twenty-seven years later, it was the Younger Pliny who wrote a graphic account of the last hours of his uncle, in a letter addressed to the historian Tacitus (vi.