ROMAN ARCHITECTURE Roman architecture owes its historical importance as much to the quantity produced as to any inherent merit of the work itself. The Etruscans, who were the early inhabitants of central Italy, were great builders and employed the arched vault in their structures. Rome complicated architecture by combining this form with that of the Greeks which, as we have seen, was based only on the post and lintel. It is readily evident that when such a simple form of construction as the post and lintel is combined with one as radically different as the arch and dome, far greater spaces without supporting columns, and a more striking impression of pomp and wealth, can be secured; but neither a finer nor a greater art necessarily results. Everywhere Roman designers worked for enrichment. Since the great Roman empire included all of the then-known world, extending over all of the ancient Mediterranean countries and northward across Gaul and even Britain, and since the Roman conquerors always built in the image of the Imperial City, the Roman love of ornamental grandeur irrespective of underlying structural principles made an enduring impression on nearly all of the peoples of Europe.
The topography of Italy, unlike that of Greece, was sufficiently open to encourage unification of the early kingdoms in a republic. As the power of the state spread, Greece being conquered in 146 B.C., Gaul in 59 B.C., and Egypt in 3o B.c., the need for centralized government of distant provinces brought about the formation of the empire. Caius Octavius (31 B.C.-A.D. 14), later known as Augustus, which became the surname of all the Roman emperors, boasted that he found Rome a city of brick and left it a city of marble. His boast is true in a sense, for in his reign the sun of Imperial Rome was at full noon and building flourished; but as a rule marble was used only as a facing, the core of the walls being formed by rubble, bricks or concrete. The rebuilding of Rome begun by Augustus was carried even farther by his immediate successors, and most of the earliest work was destroyed in the process.
The life of this victorious, self-honouring people is clearly depicted by their great forums, their law courts, their magnificent thermae or public baths, amphitheatres, bridges, triumphal arches, aqueducts and expensive town and country residences. The Romans were more practical men of the world than the Greeks, and their tastes more sophisticated, less fresh. Religion had begun to lose its grasp on the popular mind, and while it was adopted from the Greeks and kept up officially by the State, it centred more and more in a worship of imperial glory and the home, every house having an altar to its family gods.
One of the delights of Greek architecture is its perfect masonry form, marble blocks being accurately fitted together without mortar or cement by means of unequalled craftsmanship. Marble was practically the only building material Greece had. The quar ries near Rome yielded a variety of stones, but the material that made structural innovation possible was pozzolana, a volcanic earth which, mixed with lime, formed an hydraulic cement of great cohesion. The Romans do not seem to have realized the tenacious properties of this pozzolana cement which in foundations formed a solid mass capable of bearing as much weight as the rock itself. They feared also the thrust of the immense vaults over their halls, to counteract which they always provided cross walls. But when they had once covered large spaces with a per manent casing indestructible by fire, it not only gave an impetus to work in Rome, but led to a new type of plan which spread all through the Empire, and which only the differences in available materials and labour varied.
The studied and appropriate decoration of the Greeks, like their structural sincerity, disappeared in Roman architecture. The Roman legions brought home spoils from all the countries of the ancient world; niches and pedestals in Roman buildings supported alien statues. Owing to their cement, Roman builders required fewer columns to span greater spaces, and they could erect struc tures of several storeys, like the Colosseum. The column began to lose its structural significance; the engaged column and the pilaster were introduced and employed decoratively ; in buildings of more than one storey the orders were superimposed; the com posite order (q.v.), a combination of the Corinthian and the Ionic orders, was developed. The facings of the walls were highly polished, sometimes painted.
Rome was laid out in a series of splendid forums, or public squares, surrounded by public buildings, temples, basilicas, shops, porticos and colonnades, and containing arches and other monu ments in honour of victorious emperors. The forums were the vital organs of the city. In them, commerce centred, generals were acclaimed and captives were paraded. They formed the nucleus of cities and towns even on the outskirts of the empire, and are early instances of good municipal planning.
Of the ancient Roman buildings, the Pantheon (q.v.) is best preserved. Now, shorn of its once splendid embellishments, it is a Christian church known as S. Maria Rotunda. It was built by Hadrian (A.D. 120-124) and originally consisted of an immense rotunda (142ft. in diameter) covered with a hemispherical dome (14of t.' high) ; a portico was added later. Its walls are 2of t. thick and contain alternately semicircular and rectangular recesses, which probably once held statues of gods. Architecturally, its most interesting feature is its only, yet ample, source of light, a circular opening (3oft. in diameter) in the centre of the dome. The famous Colosseum (q.v.) is four storeys high, a sky-scraper for its day, though the topmost storey was not added until the first part of the 3rd century; it is notable for the excellent use of materials to accomplish desired structural effects; it records the love of entertainment that must have impelled the creation of such a vast structure solely for gladiatorial and similar exhibitions. Palaces were of a scale not conceived before or since. The villa of Hadrian extended over seven miles, and, in addition to numer ous halls, courts, libraries, etc., Hadrian attempted to reproduce in it some of the most remarkable monuments that he had seen in his travels.
The influence of Roman architecture may be divided according to its effect on (I) the world of Roman times, (2) the world im mediately following the decline of Rome, and (3) the world that came with the Renaissance (q.v.) in the 16th century. In Rome, quantity production and standardization tended to kill initiative, just as they do to-day ; love of power, wealth and comfort, and lack of spiritual incentive produced art magnificently impressive but barren of truly emotional significance. The very grossness of life ultimately turned men's thoughts to spiritual matters, and the architecture that followed Rome's decline still inspires designers of religious buildings. When antiquity became the model for Renaissance artists, Rome had so many classical monuments that its style was dominant. No other period in history has received the study and research given to the Roman, and this, too, has helped to impress its spirit on modern architecture. Finally, science and machines excluded, the civilization of imperial Rome differed but slightly from ours ; the seeming appropriateness of the Roman spirit to-day is therefore easily understood. (See also