In November, 1758, a smart shock of earthquake caused the cone of the great crater to fall in, but no eruption followed. In 1759, 1763, 1766, and 1780, eruptions were noted, and on May 18, 1780, a fissure opened on the southwest side of the mountain and extended from the base of the great crater for seven miles, terminating in a new mouth from which a stream of lava emanated. This encountered the cone of Palmintelli in its course, and separated into two branches, each of which was about 4,000 feet wide. Other mouths opened later in the year, and emitted larger quantities of lava, while in 1781 and 1787 there were slight eruptions. Five years later a fresh outbreak occurred; earthquakes were prevalent, and vast volumes of smoke were carried out to sea, seeming to form a gigantic bridge between Sicily and Africa. A torrent of lava flowed toward Aderno, and a second flowed into the Val del Bue as far as Zuccolaro. A pit called La Cisterna, forty feet in diameter, opened in the Piano del Lago near the great cone, and ejected smoke and masses of old lava saturated with water. Several mouths opened below the crater, and the country round about Zaffarana was desolated. In 1797, 1798, 1799, 1800, 1802, 1805, and 1808 slight eruptions occurred. In March, 1809, no less than twenty-one mouths of fire opened between the summit of the mountain and Castiglione, and two years afterward more than thirty mouths opened in a line running eastward from the summit for five miles. They ejected jets of fire, accompanied by much smoke. In 1819 five new mouths of fire opened near the scene of the eruption of 1811; three of these united into one large crater, and poured forth a quantity of lava into the Val del Bue. The lava flowed until it reached a nearly perpendicular precipice at the head of the valley of Calanna, over which it fell in a cascade, and being hardened by its descent, it was forced against the sides of the tufaceous rock at the bottom, so as to produce an extraordinary amount of abrasion, accompanied by clouds of dust worn off by the friction. Mr. Scrope observed that the lava flowed at the rate of about three feet an hour nine months after its emission.