In order to drain these marshes an accumulation of difficulties will have to be surmounted. A range of wooded dunes bounds the marshes on the west. Having crossed these, we enter a second zone of marshes, which are separated from the sea by a second range of dunes, extending northward from the Monte Circello, and likewise densely wooded. These two formidable barriers would have to be surmounted in order to drain the marshes towards the west. Nor are the prospects more promising in the direction of Terracina, for there, too, every outlet is stopped by dunes. The streams and canals crossing the marshes are, moreover, choked up with a dense {267} growth of aquatic plants, which impedes the circulation of the water, feeble though it be. Herds of buffaloes are sometimes driven into these streams to trample down the vegetation, but neither this barbarous procedure nor the more regular process of mowing has availed against its rapid and luxuriant growth, and the water remains stagnant. Rains are not only heavy in this portion of Italy, but the superabundant waters of neighbouring river basins actually find their way through subterranean channels into the depression occupied by the Pontine Marshes. This happens after heavy rains in the case of the Sacco, a tributary of the Garigliano, and of the Teverone, a tributary of the Tiber, and to this circumstance {268} must be ascribed the curious fact first ascertained by M. de Prony, viz. that the volume of water annually discharged by the Badino, which drains the marshes, exceeds by one-half the whole of the rain which annually descends upon them. When this happens the whole of the country is under water. Another danger arises during dry weather. It happens then occasionally that the parched vegetation is ignited through the carelessness of herdsmen; the fire communicates itself to the turfy soil, and the latter smoulders until the subsoil water is reached. In this manner tracts of land which were looked upon as secure against every inundation are converted into marsh. During the greater portion of the year the Pontine Marshes present the appearance of a plain covered with herbage and flowers, and it is matter for surprise that a country so fertile should be without inhabitants. The town of Ninfa, which was built in the eleventh century, near the northern extremity of the plain, has since been abandoned, its walls, houses, and palaces still remaining, covered with ivy and other creeping plants. There can be no doubt that our engineers would be able to reclaim this desolate region. The system adopted in the case of the valley of the Chiana may not be practicable, but other, if more costly, means may be devised. Whatever the outlay, it is sure to be productive, for even now the marshes yield rich harvests of wheat and maize. * * * * *