Hadrian was responsible for rebuilding the Pantheon, a temple dedicated to all gods (Figures 23.9, 23.10, and 23.11). The Pantheon was originally built in 27 BC by Marcus Agrippa, a confidant of Augustus. Damaged in a fire of AD 80, the temple was restored by Domitian. Hadrian’s version was a complete rebuilding; the architect of this unique design is unknown, but Hadrian himself surely took a great interest in it. All traces of the earlier plan were obliterated, although Agrippa’s dedicatory inscription was kept, curiously enough. Turned into a Christian church with few modifications of the Hadrianic structure, the building has been extremely well preserved. Today, however, the setting differs: the surrounding ground level is much higher than in antiquity, and the rectangular court lined with porticoes that originally lay in front of the temple, focusing attention on the temple’s entrance, is now replaced by a square with streets heading off in all directions.
The construction of Hadrian’s Pantheon began in ca. 117 and was finished by 126—128, according to its brick-stamps. Brick-stamps represent a distinctive component of the archaeological record of imperial Rome. Baked bricks were used as building materials from the time of Augustus, with great popularity from Nero to Hadrian. The bricks made in and around Rome were stamped with different types of information from the reign of Augustus through Caracalla, then again from the reign of Diocletian (284—306). This information could include: the type of product; the source of the clay or the name of the brickyard; the owner of the clay source; the brick maker; or the consuls in office when the brick was made. This last is especially useful for dating purposes from AD 110 to 164, the period when consuls might be named in stamps, because consuls, well known from literary sources, served for one-year terms.
The unusual design of the Pantheon combined traditional Etruscan (Tuscan) and Greek architectural features with innovations. The temple consists of two parts: a Tuscan-Greek porch
Figure 23.10 Plan, Pantheon
Figure 23.11 Cross-section, Cella, Pantheon approached from a large colonnaded court, and, behind, a circular cella covered by a hemispherical dome. The two join awkwardly by means of an intermediate zone with niches. The porch, deep with a broad flight of steps on the front only and raised on a podium, all in the Tuscan manner, is covered with a pediment and gabled roof held up by monolithic columns of Egyptian granite with Corinthian capitals. Marble, widely used, gives an elegant effect. The cella, in contrast, is made largely of concrete, with brick and stone elements. Here the builders developed innovative construction techniques, although much is hidden from the visitor’s eye. The walls are not solid, but are composed of vaulted spaces, one on top of the other. The vaults of bricks redirect the downward pressure toward the eight massive piers in the circle and give variety and resilience to the structure. The dome itself is made of concrete that was poured over a huge wooden frame, the weight of the concrete lightened with inclusions of pumice instead of the heavier aggregate used in the lower walls.
Although the hemispherical dome springs from the internal wall at a height equal to the radius of the dome, the exterior wall rises well above this starting point, permitting the extra support of buttressing against the lower part of the dome. Because of this compensation, from the outside one cannot discern the complete shape of this dome. Instead, the dome appears shallow, only slightly curved.
The inside reveals unimpeded the full hemisphere. The dome is decorated with coffers, or squares one inside the other. Originally a gilded bronze rosette decorated the center of each coffer; with light reflecting on them, these rosettes must have seemed like stars. At the top is an oculus, an opening to the sky. The worshipper can look up into the heavens; sunlight and rain and even snow penetrate the temple. The sun as it crosses the sky illuminates a different spot with each passing minute. Drain holes in the floor carry off water.
The dome of the Pantheon had great influence on post-antique architecture. In religious architecture the embodiment of the divine, the celestial, as in the Byzantine Haghia Sophia or the Islamic Dome of the Rock, in a secular building such as the Capitol in Washington, D. C., the dome represents the triumph of human thought and rationalism, the symbol of a certain idea of Roman civic order. No need to be surprised, then, by the first three lines of an inscription installed in 1632 by Pope Urban VIII at the rear of the Pantheon’s porch: “The Pantheon, the most celebrated edifice in the whole world” (MacDonald 1976: 94).
World History
