Rome

by M. A. R. Tuker; Hope Malleson

Four of these ancient aqueducts are still in use. The Virgo, built by Agrippa in 27 b.c., and now known as the Trevi; the Alexandrina, constructed by Alexander Severus (222-235), probably to supply his own baths, and now known as the acqua Felice; the ancient Trajana, now Paola, and the Marcian, restored by Pius IX. The Marcian was always considered the best drinking water, and the Trevi being a softer water was preferred for bathing purposes.

The amphitheatre alone was, perhaps characteristically, a building of purely Roman origin. Intended for shows and fights of gladiators and wild beasts, these were at first temporary wooden structures. The only stone predecessor to the great Flavian amphitheatre was a smaller building in the Campus Martius, the work of Statilius Taurus in 30 b.c. The Colosseum was begun by Vespasian in a.d. 72, was dedicated eight years later by Titus, and was completed by Domitian. It stands upon the site of Nero's artificial lake, is one-third of a mile in circumference, covers some 6 acres of ground, and is 160 feet in height. It could seat 87,000 spectators, and its staircases, galleries, and entrances are so admirably planned that this crowd of sight-seers must have found their seats and filed out when the show was finished with little delay and difficulty. The numbers of the entrances, cut in stone, can still be seen over each of the arches. The Colosseum is built entirely of travertine, the blocks are fitted together without mortar and are studded with holes from which the greedy despoilers of the middle ages wrenched the metal clamps. In spite of its having been used as a fortress and served as a stone quarry for centuries, it is still one of the most magnificent of the monuments of Rome.

The solidity of the public buildings seems to have been in marked contrast to the flimsy nature of the common dwellings or insulae. In the time of Augustus these numbered 46,600, the domui, or houses of the rich, 1790. The former were roofed with timber or thatch. As land was dear, they were often of several stories and perilously high; many of them were built of unbaked bricks with projecting upper floors, and they were constructed with wooden framing filled in with rush and plaster, so that when a fire broke out in the city whole regions were laid waste in a few hours. As a measure of safety Augustus limited the height of the insulae to 70 feet, and Trajan reduced this again to 60 feet, while a distance of 5 feet between each house was prescribed by the law of the Twelve Tables.

The volcanic tufa used by the earliest Roman builders was discarded gradually in favour of better materials. Peperino, a grey-green volcanic stone from the Alban hills, began to take its place, and was used for the construction of the Tabularium in 78 b.c. and for Hadrian's mausoleum. It was cut in the same way in large rectangular blocks, clamped together during the Republican and early Imperial periods with iron. Mortar was not used till later, and at first served only to level the surfaces of the stones; it came into use for binding bricks together only at a later and degenerate period of architecture. Travertine was adopted towards the first century b.c. It is a cream-coloured stone hard and durable though easily calcined by fire, formed by deposit in running water. It was quarried at Tivoli and on the banks of the river Anio, where it is still plentiful. To the present day the quarries are worked at Tivoli, and the stone is brought to Rome on waggons drawn by immense white oxen which pace majestically along the dusty roads beneath the goad of their wild-looking drivers.

The chocolate-brown earth imported from Pozzuoli or dug from beds in the campagna, is known as pozzolana, and early in the history of Rome her builders discovered that when mixed with lime it made a remarkably strong cement. As such they used it for foundations, for the lining of walls and ceilings. With pieces of brick and stone a concrete was formed which was poured in a liquid state between wooden casings, and when set proved to be one of the hardest and most durable of the materials used. It was the strength of this concrete which enabled the Roman builders to give the vaults of their baths and basilicas such an enormous span; and it could be used for the flooring of upper stories without beams or supports. When especial lightness was required, the concrete was made with broken pumice stone.

TEMPLE OF MARS ULTOR
The temple erected by Augustus in his Forum to the God of War under the title of Mars the Avenger. Only the upper part of the ancient arch of the Forum, now known as Arco de' Pantani, is visible. This represents the first imperial building in Rome. See pages [3], [30].

After the first century b.c. concrete became a favourite building material. The walls so made were lined with stucco and faced without in various fashions, the variety of the facing determining with considerable accuracy the date of the fabric. The earliest facing, of the first and second century b.c., was of irregular blocks of tufa set in cement, and is known as the opus incertum. This was replaced in the middle of the first century b.c. by tufa blocks cut in squares and set diagonally giving the appearance of a network and hence known as opus reticulatum. In or after the first century a.d. this fashion was superseded by a facing of triangular bricks set point inwards, and by the end of the third century bricks were mixed with the opus reticulatum, a style known as opus mixtum. To the casual observer the narrow brown bricks of the ruined buildings of ancient Rome seem to play an important part, but, with few exceptions, they are merely a brick facing upon concrete.

Up to the first century b.c. there was little or no splendour or decoration introduced into the buildings of Rome, and the city of Augustus' inheritance was a city of sober-hued, volcanic rock. When marble was first sparingly used, Livy reprobates it as too showy and extravagant. Notwithstanding, the fashion rapidly spread, first in the embellishment of public buildings, then for private houses as well until in the first century of the Empire it became a common building stone.