This eruption of Skaptar was preceded by several outbreaks in the sea; some of them close to the shore; some many miles from land. Such phenomena have become tolerably familiar. Livy informs us that a disturbance of this kind near Sicily, occurring with similar phenomena at the time of Hannibal’s death, so terrified the Romans as to induce them to proclaim a day of supplication to the gods to avert their displeasure. Santorin in the Grecian Archipelago is a similar production. And in 1831 an island was thrown up to the southwest of Sicily, where previous soundings had shown a depth of six hundred feet. It was preceded by a violent spouting of steam and water. The sea around was filled with floating pumice and dead fish. The crater reached a height of two hundred feet, being three miles in circumference. Its circular basin was full of boiling, dingy, red water. It continued active three weeks, and then slowly sank, leaving a dangerous reef eleven feet below the surface; while a single black volcanic rock projected from the sea near the center of the reef. It is known as Graham’s Island. Thus we see that volcanic action is not confined to the land, and that the areas affected are continually shifting. Jorullo, in Mexico, affords an example of the way in which new volcanoes are constantly being formed. In the parallel of the City of Mexico exist five volcanoes, extending in a line across the country as if thrown up along some immense fissure or subterranean fault, extending from sea to sea. Of these Popocatepetl is perhaps the largest, and Jorullo the most recent. There formerly existed in Mexico an extensive plain of remarkable fertility, covered with fields of cane, cotton and indigo, and watered by irrigation from the reservoirs in the basaltic mountains that bounded it. This region, the _Malpays_, had no volcano within eighty miles, and lay twenty-six hundred feet above the sea. In June, 1759, alarming rumblings were heard in the earth, which were succeeded by severe earthquakes. These phenomena lasted several weeks, to the great consternation of the inhabitants. In September it seemed that quiet was restored, when suddenly, on the night of the 28th, a fearful subterranean noise was again heard; fissures opened, and hot stones were thrown out. Part of the plain rose up like [Illustration: JORULLO.]