Another great earthquake occurred on the coast of Chile on the 19th of November, 1822. This shock was felt simultaneously over a distance of 1,200 miles from north to south. It reached its greatest intensity about 100 miles north of Valparaiso. This earthquake caused a rising of the coast to a height of from three to five feet. From careful examinations it appears that the area over which a permanent elevation of the country took place must have been equal to 100,000 square miles, an area equal to about half of the area of France, and five-sixths that of Great Britain and Ireland. "If we suppose," says Dana, "the elevation to have been only three feet on an average, it will be seen that the mass of rock added to the continent of America by the movement, or, in other words, the mass previously below the level of the sea, and after the shock, permanently above it, must have contained fifty-seven cubic miles in bulk; which would be sufficient to form a conical mountain two miles high (or about as high as Etna) with a circumference at the base of nearly thirty-three miles.... Assuming the Great Pyramid of Egypt, if solid, to weigh in accordance with the estimate before given 6,000,000 tons, we may state that the rock added to the continent by the Chilian earthquake would have equalled more than 100,000 pyramids. "But it must always be borne in mind that the weight of rock here alluded to constituted but an insignificant part of the whole amount which the volcanic forces had to overcome. The thickness of rock between the surface of Chile and the subterranean foci of volcanic action may be many miles or leagues deep. Say that the thickness was only two miles, even then the mass which changed place and rose three feet, being 200,000 cubic miles in volume, must have exceeded in weight 363,000,000 pyramids." The shocks of this earthquake continued from the time of its occurrence, on November 19th, 1822, to the end of September, 1823, and even then there were scarcely two days that passed without a shock. On the 20th of February, 1835, the same part of the world was in the throes of an earthquake that was felt nearly 1,000 miles from north to south, or from near the town of Concepcion to the Isle of Chiloe, and from east to west a distance of about 500 miles, from Mendoza to the island of Juan Fernandez, which you probably know better as Robinson Crusoe's Island. By this earthquake the new town of Concepcion and several other towns were partly destroyed.