Pantheon Essays (681 words) - Domes, Pantheon, Rome, Pantheon

Pantheon Pantheon, temple dedicated to all the gods. The Pantheon of Rome is the best-preserved major edifice of ancient Rome and one of the most significant buildings in architectural history. In shape it is an immense cylinder concealing eight piers, topped with a dome and fronted by a rectangular colonnaded porch. The great vaulted dome is 43.2 m (142 ft) in diameter, and the entire structure is lighted through one aperture, called an oculus, in the center of the dome. The Pantheon was erected by the Roman emperor Hadrian between AD 118 and 128, replacing a smaller temple built by the statesman Marcus Vipsanius Agrippa in 27 BC. In the early 7th century it was consecrated as a church, Santa Maria ad Martyres, to which act it owes its survival (see Architecture). The term pantheon also refers to a building that serves as a mausoleum or memorial for eminent personages of a country. The most famous example is the Church of Sainte Genevi?ve in Paris, designed (1764) in the classical style by the French architect Jacques Germain Soufflot. It was later secularized, renamed the Pantheon, and used as a temple to honor the great of France. Built in Rome, AD c.118-28, in the reign of Emperor Hadrian, the Pantheon is the best preserved and most impressive of all Roman buildings. It has exerted an enormous influence on all subsequent Western architecture. The Pantheon asserts the primacy of space as contained volume over structure in the most dramatic fashion. From the time of the Pantheon onward, Roman architecture was to be one of spatial volumes. The Pantheon was designed and built by Hadrian to replace an earlier temple established by Agrippa (the misleading inscription in the entrance frieze refers to this earlier edifice). The existing structure is an immense round temple covered by a single dome, fronted by a transitional block and a traditional temple portico of eight Corinthian columns carrying a triangular pediment. Originally, the awkward juxtaposition of these three sections was softened by a rectangular forum in front of the temple. The temple is deceptively simple in appearance, consisting of a circular drum carrying a hemispherical dome with an inside diameter of 43.2 m (142 ft). The proportions are such that, if extended to the floor, the curve of the inner surface of the dome would just "kiss" the floor; thus, a perfect sphere is contained, a symbolic reference to the temple's dedication to all the gods--pan ("all") plus theos ("god")--in the sphere of the heavens. The drum and dome are of solid monolithic concrete, reinforced with bands of vitrified tile. The vertical gravity loads are collected and distributed to the drum by relieving arches incorporated in the concrete. The wall of the drum, 6.1 m (20 ft) thick, is hollowed out by a series of alternately rectangular and curved niches or recesses. Thus, the drum is transformed into a series of massive radial buttresses, lessening its deadweight without decreasing its strength. The weight of the upper sections, and thus the magnitude of the thrusts, was reduced by varying the density of the filler in the concrete, from pumice in the upper dome to tufa in the middle sections and dense basalt in the foundations. The visually compressive effect of the dome on the inside is lessened by deep coffers (indentations) radiating down from the central oculus ("eye")--9.1 m (30 ft) in diameter--the only window in the building. Because the oculus is open to the sky, the floor is slightly concave with a drain at the center. The building was converted into a church dedicated to Mary (Santa Maria Rotunda) in 609, and therefore it escaped destruction. It is the only Roman building to retain its marble revetments, mosaics, and stuccowork. The huge bronze doors (7 m/24 ft high) are the largest Roman doors to survive in place and remain in use. Leland M. Roth Bibliography: Boethius, Axel, and Ward-Perkins, J. B., Etruscan and Roman Architecture (1970); MacDonald, William L., The Pantheon (1976); Ward-Perkins, J.B., Roman Imperial Architecture (1981).