Page:Great Neapolitan Earthquake of 1857.djvu/221

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CONNECTION OF VALLEYS—RIVER COURSES.
171

The connection between one valley and another, at a not greatly different level, is not unfrequently through a gorge or serrated cleft, fractured through the rock, in the bottom of which a torrent mars, while the road or mule tract is over the shoulder above; such are Campostrina, between the valleys of the Calore and Tanagro—and that of the Gioija, at Muro. In general, however, the valley bottoms are at different levels, and are reached by passing over low shoulders between them, the streams finding vent in sinuous, but not very deep ravines.

The lower mountain ranges, of the cretaceous limestone are not very steep, though the slopes can nowhere, except in the rolling plain country, be called gentle. The higher ridges, are always steep, and frequently characterized by a shaggy bristling grandeur, of crest and outline, greater than one is prepared to find in mountains, of a formation so recent.

The fall of the rivers generally, throughout the kingdom is rapid, the mean breadth of the land, not giving an average length of bed, of much above a hundred miles, in which the average fall is probably above 3,000 feet; and even the great rivers, have their volume so augmented in winter, that on reaching the seaboard plains, their velocity is still very great, on debouching into the sea. Thus, the Salaris, after having traversed the plain of Pæstum, retains a mid-surface, winter velocity, of about eight feet per second.

The towns in the earthquake region to which this Report refers, are nearly all built, as stated, upon rocky eminences, within the mountainous region; in some cases, however, within it, they are (or were) built upon the alluvial clay deposit, on the level of their respective Piani.