Page:Great Neapolitan Earthquake of 1857.djvu/501

Rh The barometer stands at 26.50 inches, thermo. 42° Fahr. at 12:30 and the elevation above the sea at Naples is 3158.3 feet. At Tardiano, the contrary slope towards the valley basin of the elevated mountain lake, the gloomy Lago Maorno commences. This lake is commonly pronounced Lago Maouri by the peasantry. Many singular beds of metamorphic shales, and indurated clays, with some thin seams as hard as chert or jade, and, lithogically, very like the latter, are passed, and at about 500 feet above the level of the Lago Maorno, where the descent has become again very steep, along by the northern side of a nameless torrent that discharges into it, great beds of intensely hard, flinty, and hæmatitic, dark-blue grey limestone occur, with huge seams of very hard, black and brown hæmatite, 12, 15, 24, and 30 inches thick. All these run here in a general direction, for a considerable way, nearly east and west, but as they extend, are much twisted towards the north. They are very nearly vertical, their dip being only 15° to the south. The torrent separates these beds to the south from the cretaceous limestone which here makes its appearance once more. Sloping up steeply to the north for more than half a mile, with a bare, weathered, and water-furrowed surface, without a blade of vegetation, extend parallel, and nearly vertical beds of green, grey, and purple clays, alternating with beds of yellow, soft, clayey sandstone, many yards in thickness, standing in ridges high above the worn-down clays. (See enlarged plan and section, Diagram No. 242.) My attention was directed, in particular, to these beds of ferruginous rock here, by finding that the compass would no longer work, the needle turning round 90°, within a few paces' change of