FROM Gaeta, where the south end of the Volscian range borders abruptly upon the sea, to the peninsula of Sorrento, a broad gulf stretched in remote ages, cutting its way far into the land. Its waves dashed upon the base of the mountains which now, rising with steep slope, mark the eastern boundary of the Campanian Plain -- Mt. Tifata above Capua, Mt. Taburno back of Nola, and lying across the southeast corner, the huge mass of Monte Sant' Angelo, whose sharply defined line of elevation is continued in the heights of Sorrento.
This gulf was transformed by volcanic agencies into a fertile plain. Here two fissures in the earth's crust cross each other, each marked by a series of extinct or active volcanoes. One fissure runs in the direction of the Italian Peninsula; along it lie Monti Berici near Vicenza, Mt. Amiata below Chiusi, the lakes of Bolsena and Bracciano filling extinct craters, the Alban Mountains, and finally Stromboli and Aetna. The other runs from cast to west; its direction is indicated by Mt. Vulture near Venosa, Mt. Epomeo on the island of Ischia, and the Ponza Islands.
At three places in the old sea basin the subterranean fires burst forth. Near the north shore rose the great volcano of Rocca Monfina, which added itself to the Volscian Mountains, and heaping the products of its eruptions upon Mons Massicus, -- once an island, -- formed with this the northern boundary of the plain. Toward the middle the numerous small vents of the Phlegraean Fields threw up the low heights, to which the north