41. We have a more detailed account of the eruption of 1669 than of any previous outburst. It was observed by many men of different nations; and we find accounts of it in our own _Philosophical Transactions_, in French, and of course in Italian. Perhaps the most accurate and complete description is that given by Alfonso Borelli, Professor of Mathematics in Catania. The eruption was, in every respect, one of the most terrible on record. On the 8th of March the sun was obscured, and a whirlwind blew over the face of the mountain; at the same time earthquakes commenced, and continued to increase in violence for three days, when Nicolosi was converted into a heap of ruins. On the morning of the 11th a fissure nearly twelve miles in length opened in the side of the mountain, and extended from the Piano di S. Leo to Monte Frumento, a mile from the summit. The fissure was only six feet wide, but it seemed to be of unknown depth, and a bright light proceeded from it. Six mouths opened in a line with the principal fissure; they emitted vast columns of smoke, accompanied by loud bellowings which could be heard 40 miles off. Towards the close of the day, a crater opened about a mile below the others, and it ejected red hot stones to a considerable distance, and afterwards sand and ashes which covered the country for a distance of 60 miles. The new crater soon vomited forth a torrent of lava which presented a front of two miles, it encircled Monpilieri, and afterwards flowed towards Belpasso, a town of 8000 inhabitants, which was speedily destroyed. Seven mouths of fire opened around the new crater, and in three days united with it, forming one large crater 800 feet in diameter. The torrent of lava all this time continued to descend, and it destroyed the town of Mascalucia on the 23rd of March. On the same day the crater cast up great quantities of sand, ashes, and scoriæ, and formed above itself the great double-coned hill now called Monti Rossi from the red colour of the ashes of which it is mainly composed. On the 25th very violent earthquakes occurred, and the cone of the great central crater was shaken down into the crater for the fifth time since the first century A.D. The original current of lava had divided into three streams, one of which destroyed S. Pietro, the second Camporotondo, and the third the lands about Mascalucia, and afterwards the village of Misterbianco. Fourteen villages were altogether destroyed, and the lava was on its way to Catania. At Albanelli, two miles from the city, it undermined a hill covered with cornfields, and carried it forward a considerable distance; a vineyard was also seen to be floating on its fiery surface. When the lava reached the walls of Catania it accumulated without progression until it rose to the top of the wall, 60 feet in height, and it then fell over in a fiery cascade, and overwhelmed a part of the city. Another portion of the same stream threw down 120 feet of the wall, and flowed into the city.