Many such incidents as this may have been experienced in the history of ancient Rome. They would be quite enough to fill the minds of the populace with terror, and to call for a nine days' expiation and lustration of the city. The traditional legend of the chasm that opened in the Forum, and into which Curtius threw himself in full armour to propitiate the gods and save the city, may very well have been founded on a real event of this nature. The lake or quagmire in the Forum may have been another Lagopuzzo, rent open by an outburst of gas. The subterranean rumblings and bellowings (_boati_), which were accounted such dire portents in old times, were exactly repeated near Monte Soracte in the autumn of 1831. Before we pass from this volcanic period to the consideration of the next phase in the history of the Campagna, it may be noted, as an interesting feature in the growth of the Italian peninsula, that the subterranean energy has been slowly dying out from north to south. The volcanoes of Central Italy have long since entered into the closing or Solfatara stage, when only steam, hot vapours, and gases are emitted. But at the southern end of the chain lies the still vigorous Solfatara of Naples, with the various cones around it, some of which have been in eruption within the last few centuries, while Vesuvius continues to maintain a persistent though variable activity. Still farther south lie the Æolian Islands, where Volcano occasionally breaks out, while Stromboli remains, as it has done since the beginning of authentic history, in a state of constant ebullition and eructation. At the far extremity of the volcanic belt rises the colossal cone of Etna, which from time to time displays an energy worthy of its place among the great volcanoes of the globe.