CAMPAGNA DI RomA, formerly Campania, is a province of Italy, which comprehends the greater part of ancient Latium. It is bounded on the north by Sabina ; on the east and south cast by Abruzzo Ultra, and La voro ; on the south west by the Mediterranean; and on the north west by the Patiimony of St Peter.
The Campagna di Roma, which is about 45 miles broad in almost every direction, is, as its name denotes, a flat and level district, interspersed with but few eleva tions. In approaching Rome from the north, the sky-line towards the south and south-west has the appearance of one uninterrupted level, except where the dome of St Peter's rises majestically above the horizon, and indi cates, at the distance of many miles, the position of Rome. The soil of the Campagna is wholly volcanic, and seems to be composed chiefly of the detritus of pu mice-stone. It is generally dry, but whereverlthere is moisture, the vegetation is very luxuriant.
The elevations of the Campagna, to the south of the Tiber, have commonly the form of great waves, whose summits are very distant from each other, and the inter vals between these elevations are valleys which drain to P form the richest meadows.
These elevations are all volcanic,' -• —e a nucleus of n, hard stone, called peperino, or citjja,, to be only the volcanic matter in a state of higher indium.,'..,,. These hills are pierced in every direction by caverns ; and M. Bonstetten, who examined this part of Italy with the greatest care, affirms, that he never could find a rock without mime' ous excavations. Many of them, which were inhabited by robbers, have been shut up by the police, and others have been concealed by the falling of the earth. These caverns, in which no marks of fusion appear, are almost always round, though they sometimes pass through rocks in a cylindrical form. Sonic of them in the neighbourhood of the famous brook of Cremera, are of a singular structure. Beds of small calcareous stones are found in the volcanic matter ; and all the hills in the neighbourhood are pierced with caves of a hr structure, which have been used as prisons or tombs. Bonstetten endeavours to explain these appearauces, by supposing that the whole of Latium was formerly a gulf of the sea, which extended to the base of the mountains — of Sabina, and that the pebbles were stratified at the time when the submarine volcanoes were in action. " Tomes ces cavernes prouvent que les •aux qui ont stratifie ces galets ont fait leur ouvrage dans le terns des volcans, qui melant leur ejections parmi les depots des fleuves, ont enfin fait sortir de la me' le sol de cette Rome, destiree comme les volcans dont tile est issue, a devenir le foyer d'autres bouleversemens."
The highcst eminence in the Campagna is Monte Al bano, now Monte Caro, which is about six leagues from Rome, and rises about 2920 feet above the level of the sea. It is united at its base, on one side, to the Algidus of the ancients ; and on the other, to Monte Velletri, and forms an immense insulated mass, situated on an ex tensive plain, and almost at an equal distance from the sea and the calcareous mountains of. Sabina. A chain of hills surrounds the base of Monte Cavo ; and on the tops of those which encircle the northern side of its base, are placed the villages of Compiti, Colonna, Monte, l'orcia, Frascati, Rocca-di-Papa, Marino, Castel Gandolfo, Al bano, Larriccia, Gensano, and Citta Lavigna. This moun tain is composed of volcanic ejections, and the Rocca-di Papa consists of tuffa.
Mount Soracte, which is about eight leagues north east of Rome, is completely insulated, and rises to the height of about 2119 feet.
The next principal eminence in the Campagna, is the Villa Millini, which is piacedon the summit of Monte Mario, about half a league tc the north: east of Rome. Its height, above the level el' the sea, is 440 feet, and as it occupies the centre of the great plain, it commands a most extensive view of the Campagna. The rock of which it consists, is filled with shells, but is slightly in durated, and the base of the bill rests on the volcanic matter which surrounds it. Bonstetten supposes that Mount Albano and Soracte have both a calcareous nucleus below the volcanic matter, and that the whole base of the Campagna is likewise calcareous. As a proof of this, he mentions that in the Grotto del Mondo, at Tivoli, large calcareous stones are found embedded in the volcanic ejections which form the vault of the ca verns. The great plain of Rome is completely free of stones, and those which do occur arc either brought them by the hand of man, or detached from sonic neje-I.'', • Mg volcanic rock. The streets of Rome, and (an cient roads, arc paved with hard lava ; an(1." the side of Palestrina, the ancient Preadt_,• that calca reous stones appear in the volcanic sok^ The volcanic ejections seem to lave had their princi , to :MOM(' Cavo, the highest elevation, is entirely enveloped, while the Villa itlillini is scarcely covered ; and on the calcareous hills to the cast the volcanic soil terminates at the height of 30 or 40 toises above the plain.