Roman building 308 363 Restoration of the corner of a wall at Herculaneum (Insula II) following the earthquake of 62. 364 Masonry at Herculaneum (III, 14) built after the earthquake of 62 with reused material, including a number of smashed amphorae. Masonry construction 309 365 Pompeii, reconstruction after the earthquake of 62. Wall made up of varied terracotta material: bricks, tiles, fragments of amphorae (IX, 6, 3). 366 Pompeii, restoration of a wall after the earthquake of 62. Among the reused material are pieces of opus signinum paving (VI, 7, 2). Roman building 310 367 A masonry column of the Great Palaestra, Pompeii, fixed into place with a layer of lead (visible at the level of the scotia) after the earthquake of 62. is done nowadays with these artificial materials (for instance VI, 7, 2 and particularly the lower portico of the villa of Diomedes). At the Large Palaestra, bordering the amphitheatre, a particularly original solution was found to put back in place accurately the columns that had been shaken by the quake. These were set upright, probably using cranes, then once in position a hole was dug at Masonry construction 311 their foot, into which lead was poured. This set much faster than mortar, permanently wedging them into place (fig. 367). The ruin of the houses, as well as the departure of the owners, brought about a change in use of certain houses that were renovated, divided between several new occupants (such as the House of the Cryptoporticus) and sometimes turned into workshops or business premises (fig. 368). In well-organized reconstructions, both public and private, great use was made of brick, a standardized material quick to produce and use that could, if necessary, be combined with the recovered rubble (fig. 369).70 368 Pompeii, façade of a domus turned into a bakery after the earthquake of 62. The high door framed with cubic capitals was hidden by the addition of a first floor; the oven, visible at the back, was constructed in the atrium (VIII, 4, 26). Roman building 312 369 Adapting to new techniques and to the modern fashion, the House of Caius Vibius (VII, 2, 18) was totally rebuilt of new brick masonry and salvaged opus incertum. Masonry construction 313 370 Brick column from the Basilica of Pompeii. Around a central cylinder are arranged the ‘petals’ forming the fluting; a stucco rendering covered the facing. Roman building 314 371 Column shaft made of bricks in irregular quarters; diameter without the rendering: 45cm. House of Terentius Proculus at Pompeii. Masonry construction 315 372 Brick column from the second peristyle in the House of the Faun at Pompeii. Restoration from 62. 9 Masonry columns If it seemed natural to include a section on columns in the chapter devoted to stone block construction, it might appear less so to do the same in this one. Nevertheless, in the peninsula this is how thousands of columns of all sizes were built. The first known example of a complex of masonry columns is that already mentioned of the basilica at Pompeii, erected around 120BC (fig. 370).71 The fluted shafts of the central colonnade, 11m high and 1.06m wide at the base, are made up of a regular assemblage of brick sections, 4.5 to 5cm thick. The whole is in the shape of a flower, composed of a circular core surrounded by 10 ‘petals’ and completed by 10 lozenge- shaped segments, so as to form an outline, seen from above, of 20 flutings. In each course the arrangement is alternated so as to overlap the joints, except of course for the central core which forms an internal column; once the columns were up they were covered with a white stucco, delicately defining the flutings and creating the illusion of marble. This achievement may well have seemed unique in the great age of its construction, but the principle was carried on and innumerable colonnades made use of bricks (figs 371, 372), such as the great complex of colonnades in the portico of the Guilds at Ostia. The method, except for the small hypocaust pillars that are piles of small discs or squares, remains the same everywhere: sections of terracotta are assembled to form a succession of circular levels, either by themselves, or around a cylindrical core of masonry. Roman building 316 Rubble masonry, particularly at Pompeii after the earthquake of 62, was used to create columns of modest size in the peristyles of houses. These were sometimes organized in a homogeneous or mixed pattern, sometimes rough and ready, with a finish of a thick coat of rendering, giving a regular tapering appearance to the shafts constructed in this way (figs 373, 374). Still on this inexhaustible site can be admired, for they are a real tour de force, the columns faced with opus reticulatum mixtum of remarkable regularity: at the southern portico of the House of the Mysteries, at the gladiators’ camp (V, 5, 3) and, above all, the finest example, a large isolated column, formerly holding a gnomon, erected behind the Forum Baths (fig. 375). 373 Masonry columns from a peristyle at Pompeii (VI, 13, 9): two are made of bricks, the third of opus mixtum; the capitals are dressed tufa. Fluted stucco decorated the outside. Masonry construction 317 374 Masonry column made of rendered rubble stones of lava. The block of the capital is tufa. Pompeii, VIII, 3, 27. Roman building 318 375 Masonry column alternating a tufa and lava reticulate and rings of bricks. Standing behind the Forum Baths at Pompeii, it carried a sun dial. 6 ARCHES AND VAULTS 1 Origins of the voussoir arch The voussoir (or true) arch is rightly considered to be one of the fundamental elements in the conquest of space, a contribution made by the Romans in their monumental architecture. An image traditionally accepted for generations was that the Etruscans were the inventors of this technique and responsible for its transmission into Roman architecture.1 It is to the Tarquins in the sixth century BC that we traditionally attribute the construction of drains, gates in city walls and vaulted tombs, providing the early models that were to inspire their successors. In fact, the reality is a lot less certain (fig. 376).2 For a long time the Cloaca Maxima, the long underground vaulted channel draining water from the low-lying Forum Romanum into the Tiber, was considered to be originally the work of the Etruscans (fig. 377). However, although in the period of the Tarquins a small natural water course leading into the river had in fact been channelled and made into a main drain, archaeological excavations have shown that the Cloaca Maxima, at first open to the sky, had been repaired and reconstructed several times, the last time by Agrippa, in the reign of Augustus. Two levels of evidence have served to confirm this on the Forum,3 as it has been possible to establish that the extrados of the vault was at a higher level than the flooring of the Republican period. The fine outflow with three rows of concentric voussoirs that can be admired today in the bank of the Tiber at the level of the Ponte Palatino can there- Roman building 320 376 The invention of the voussoir arch took place in the third millennium in regions with little wood and using unbaked brick, in Mesopotamia and the made of unbaked bricks at Ur Nile valley. This is a true arch (Iraq). (Photo: Hrand.) Arches and vaults 321 377 The outflow of the Cloaca Maxima into the Tiber, at the level of the Forum Boarium. The crown of the arch is made up of three rows of short voussoirs. The date of its construction is estimated to be the beginning of the first century BC. fore be dated to the beginning of the first century BC at the earliest. The walls of the Etruscan towns of Volterra (Velathri), Perugia (Aperusia) and Falerii Novi have monumental gates closed above by a voussoir arch which, just like the drain in Rome, have been considered to be the oldest models. The study of these ramparts has led to a more accurate assessment, and at both Volterra and Perugia,4 it has proved possible to identify the Etruscan walls and their gates that were rebuilt after the Roman conquest (fig. 378). At Falerii Novi the situation is much more interesting since this town is in fact a new city, built by the Romans, perhaps using Etruscan engineers, to rehouse the inhabitants of Falerii Veteres, besieged and taken by Rome in 241BC.5 It is possible here to be certain that shortly after this date, which forms the only definite marker in the early history of the voussoir arch, Etruscans and Romans knew the art of the true arch (fig. 379). As for the vaulted Etruscan tombs, it must be remembered that all the funerary halls from the seventh to the second century BC are either hypogea cut into the rock imitating the interiors of wooden houses (necropolises of Cerveteri, Orvieto and Tarquinia), or long spaces covered by corbelling of slabs or circular chambers, correctly given the name tholoi (tomb of Casal Marittimo or of Montagnola).6 The fine tombs covered with true Roman building 322 vaults in a full arc at Perugia (tomb of San Manno) and Bettona (20km south-east of Perugia), formerly held to be Etruscan models because of their location in that territory, are in fact Roman tombs of the second century BC (fig. 380). The fact that, as has already been mentioned, the Romans often adopted monumental techniques from the people they conquered, may have led to the attribution of the arch to the Etruscans.