Roman Architecture

The monumental city gate while sometimes serving a com memorative purpose differs from the arch in being part of the defences of the city and meant to be used. Of these one of the most famous and best preserved is the Porta Nigra at Treves. Bridges and Aqueducts.—The bridges and aqueducts of the Romans may be treated as monumental works in spite of their utilitarian character. The most famous examples of Roman aque ducts are the Pont du Gard, Nimes, and the aqueducts at Tar ragona and Segovia in Spain. Those which crossed the Campagna bringing water to Rome from the hills are also well known and impressive in their decay.

There are not many of the larger Roman bridges now remain ing. The best preserved is that built by Augustus and Tiberius at Rimini. The finest is that across the Tagus at Alcantara in Spain.

Tombs.

The larger Roman tombs consisted of an earth mound or tumulus surrounded by a ring of masonry rising usually to a considerable height. Few of these now exist, the most notable being the tomb of Cecilia Metella on the Via Appia and the mau soleum of Hadrian, now the castle of St. Angelo. The smaller tombs, in particular those known as columbaria (q.v.), are usually underground, though there is sometimes an upper storey, often in the shape of a small temple in antis, built of cut brick from which steps lead down to the tomb proper. There is a line of such tombs just outside Rome along the Via Appia and also along the Via Latina. Examples of Roman funeral monuments of various kinds exist along the Street of Tombs at Pompeii and in the provinces, in Syria at Palmyra, Jerusalem and Petra.

Palaces.

By the end of the republican period the Palatine (q.v.) hill had become by far the most desirable residential quar ter of Rome. It was therefore natural that the Roman emperors from Augustus onwards should choose to live on it, gradually acquiring further property until the whole hill, except that part hallowed by tradition or by the presence of temples, became the imperial residence. Augustus himself bought and enlarged the

house known as the House of Livia which still exists. Tiberius built a palace on the north-west side of the hill. Another palace was built on the south-east corner of the hill by Claudius or more probably by Nero. Some rooms of this palace have recently been discovered, though both it and the palace of Tiberius were partially destroyed by fire. The central space was covered by the palace of the Flavians, Domitian with his architect Rabirius being responsible for a magnificent suite of State apartments and for the sunken garden called the hippodromes. Hadrian ex tended the palace towards the forum and the House of the Ves tals and finally Septimius Severus raised a huge structure over looking the Circus Maximus, partly on the top of Hadrian's work and partly on an artificial platform supported on arches and finishing with his Septizonium. Remains of these buildings, often one above the other, cover the Palatine.

Of the famous Golden House of Nero on the site now covered by the baths of Titus, the Colosseum and the basilica of Maxen tius, very little remains.

The Villa of Hadrian (q.v.) at Tivoli, begun about A.D. I 23, was another sumptuous imperial residence with parks and gar dens on a large scale. There are remains of great brick and con crete structures and the unevenness of the site necessitated large terraces and flights of steps. All the buildings are Roman in style and method of construction, though with Greek names.

The palace of Diocletian at Spalato (Split), to which he retired on his abdication in A.D. 305, combines a palace with a fortress. It consists of an immense rectangle surrounded by walls guarded by towers on three sides and on the fourth to the south protected by the sea. The palace itself is on the south side with a great gallery 52o ft. long with 51 windows overlooking the sea. (See