The Icelandic volcanoes may be divided into three classes: (I) cone-shaped, like Vesuvius, built up of alternate layers of ashes, scoriae and lava; (2) cupola-shaped, with an easy slope and a vast crater opening at the top - these shield-shaped cupolas are composed entirely of layers of lava, and their inclination is seldom steeper than 7°-8°; (3) chains of craters running close alongside a fissure in the ground.
65), and no mention is made of the great eruption of Vesuvius (A.D.
The brief notices of the classical writers inform us that Herculaneum' was a small city of Campania between Neapolis and Pompeii, that it was situated between two streams at the foot of Vesuvius on a hill overlooking the sea, and that its harbour was at all seasons safe.
It is quite possible that she was the Rectina whom Pliny the elder wished to assist during the disaster of Vesuvius, for her husband, Voconius Romanus, was an intimate friend of Pliny the younger.
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.