The earliest Roman works of architecture were of a purely utilitarian character, and in addition to the Cloaca Maxima already mentioned the most noteworthy still in existence are the bridges over the Tiber, the aqueducts of the Campagna outside Rome, and the so-called Pont du Gard at Nîmes, France. The most ancient temples greatly resemble those of Greece, and amongst them may be named as specially typical those of Fortuna Virilis and of Antoninus and Faustina, both now in use as churches, and that of Venus and Rome, all in the capital, that of Diana at Nîmes known as the Maison Carrée, and that of the Sun at Baalbec. Of later date are the beautiful circular temples, of which the grandest example is the Pantheon of Rome, built under Hadrian about A.D. 117, in which Roman architecture reached its noblest development. The colonnaded porch with entablature and pediment, that detracts so much from the external effect of this magnificent building, did not originally belong to it, but formed the entrance of a temple built by Agrippa more than a century before, and was added to the Rotunda after the completion of the latter. The internal diameter of the Pantheon is 142 feet 6 inches, and its height at the apex of the dome is the same; its walls are 20 feet thick, and its concrete dome is adorned with deeply recessed panels or coffers and has a single circular opening at the crown through which alone light is admitted. The floor is of marble; bronze pilasters flank doorways of the same metal, the oldest existing specimens of their kind, and it is supposed that when first completed the whole of the outside was cased in white and the inside in coloured marbles.
Other circular temples of Roman origin, but on a much smaller scale than the Pantheon, are the Temple of Vesta and that in the Forum Boarium, Rome, the latter much injured and spoiled by a modern roof quite out of character with it; the one at Tivoli near the capital, known as that of the Sybils, still beautiful in spite of the loss of much of its entablature and many of its columns; the Temple of Jupiter at Spalato with a domed roof upheld by columns; and that at Baalbec, which has the distinctive feature of a curved instead of a perfectly flat entablature.
A very special interest attaches to the Roman basilica on account of its having so long been supposed to have been the type on which the earliest Christian churches were built. Basilicas were used as courts of justice and exchanges, more rarely as market-places, and the most ancient are said to have been merely square spaces, enclosed within rows of columns open to the air, that were however soon succeeded by walled buildings roofed with timber or with vaults of concrete supported on massive piers of stone. In them a raised semicircular space at the eastern end was divided off by columns known as cancelli for the use of the magistrate and his lectors, and between it and the main body of the hall, which was divided by columns into a nave and aisles, rose the altar on which sacrifice was offered up before any business of importance was entered upon.
A good example of an early Roman basilica is that called the Ulpian in the Forum of Trajan, Rome, dating from A.D. 98, which is said to have had a flat roof and double aisles, the latter surmounted by galleries, whilst that of Maxentius and Constantine, the ruins of which are known as the Temple of Peace, also in the capital, of considerably later date, A.D. 312, had a groined central roof and barrel-vaulted side aisles.
| Roman Doric Column and Entablature | Roman Ionic Column and Entablature | Roman Corinthian Column and Entablature |
It was in their Thermæ or Baths rather than in their Temples and Basilicas that the Roman architects achieved their greatest triumphs. These were vast complex structures fitted up with every conceivable luxury for the use of bathers, with a large hall artificially heated and known as the tepidarium, open colonnaded courts, and many subsidiary buildings including gymnasia, debating rooms, &c. They combined simple grandeur of structure with rich internal decoration. The most ancient Thermæ in Rome, of which extensive remains still exist, were those of Caracalla, erected in A.D. 217, already referred to in connection with the earliest use of the contrivance which foreshadowed the pendentive. Rising from a lofty platform, the noble tepidarium was roofed in by three fine intersecting vaults, and its walls were cased in marble. With their supplementary buildings the baths covered a space some 110 yards square, and beneath them were many vaulted rooms for the attendants on the bathers. Amongst their ruins were found the masterpieces of sculpture known as the Farnese Hercules and the Farnese Bull, but when they were first placed there, there is no evidence to prove.
