I.—The Mechanism of Stromboli

Mr. R. Mallet—whose theory on the source of volcanic heat was noticed in a former number of this Magazine—has followed it up by a second paper, read before the Royal Society in June last, and published in the last number (155) of the Proceedings, upon “The Mechanism of Stromboli,” one of the Lipari Islands, well known for the permanence of its volcanic activity, which seems to have been incessant for the last two thousand years at least. This insular and conical mountain rises more than 3,000 feet above, from a depth of nearly 2,000 feet below, the level of the Mediterranean, and exhibits the usual structure of a volcano, having an old breached crater on one side, from the bottom of which red-hot scoriæ and fragments of lava are thrown up, together with much steam, by explosions occurring at irregular intervals of from two or three to thirty or even occasionally forty minutes.