south of the city of Mexico. Proceeding westward from the Capital, it was perceived again in Morelia, and it became so violent in the direction of Acapulco, that it destroyed houses, cracked the earth, and finally plunged into the sea, whose waves rose and swelled as under the influence of a violent storm. During its continuance of nearly five minutes, there were no meteoric phenomena worthy of note, no subterranean noise, and no perceptible change in the altitude of the barometer, in the city of Mexico.
Standing on the summit of Popocatepetl and looking over the immense panorama—which now lay spread like a map at his feet—Mr. Von Gerolt compared his repeated examinations of the geology of the valley and of the adjoining departments, and he came to the conclusion, that both the volcano and the vale owe their origin and present condition to some violent eruption, by which the actual surface has been raised from the interior to its present level, through the primitive and transition rocks; and that in the mining districts of the states of Puebla, Mexico and Michoacan, the rich veins, manifested in slaty formations, or in metallic porphyry, are but the trifling remains or islands, as it were, left rising above the plain, after the fiery deluge that swept over portions of our Continent.
But (turning to the prospect around them, from the examination of the crater of that vast stack, which pours forth the smoke and vapors of the central fires, and acts, perhaps, as the great safety-valve of a large part of the New World,) the travellers speak of the immense picture that lay before them as indescribably sublime.
The day was remarkably clear. Few clouds, and those very high in the air, appeared against the sky, which was almost black with the intensity of its azure; and, as far as the eye could reach, in every direction) there was one uninterrupted waving of mountain, valley and plain, until (almost without a horizon) the earth and the sky blent in vapory blueness. In the midst of the eastern plain, the tall cone of Orizaba stood up in bold relief against the sky, with its snowy peak glittering like a point of flashing steel. Below them, near two thousand feet, lay the summit of Iztaccihuatl, covered with snow, and exhibiting not the slightest evidence either of crater or volcanic action.
After enjoying this splendid panorama as long as their enfeebled condition would allow them, erecting a flag-staff, and making the sketch I have placed at the commencement of this letter;—the travellers, at four o'clock, began a descent, which they describe as not the least difficult portion of their enterprise. If they complained of the toilsome slowness of climbing, they could now with equal justice complain of the dangerous swiftness of their return. The day was far advanced; the cool wind of the evening had already frozen the surface that melted under the noonday sun, and, passing over the sands and snows at a sharp angle, they
