Rome Art & Architecture: THE PANTHEON
Often considered not just the most perfect Roman temple but the apogee of Roman architecture, the Pantheon, the temple to all the gods, was the emperor's Hadrian's supreme architectural achievement in Rome.
Its fame derives in part from its unusually well-preserved state (it was converted into the church of Santa Maria ad Martyres in AD608) but is indisputably merited as one of the most sublime of Roman buildings.
Two earlier temples had been built on the same site, one by Agrippa in 27BC and one by Domitian when Agrippa's templed burned down in AD80. Built between AD118-25, the Pantheon is composed of three rather disparate elements: a huge colonnaded porch, a tall middle block, and the rotunda that forms the temple's cella and supports its dome.
The porch has 16 giants columns of the Composite order. These are made of grey and red Egyptian granite, with bases and capitals of white Carrara or Greek marble. With an eagle on top of its pediment, the porch originally dominated a colonnaded piazza in front, looking higher than it does now (the surrounding ground has risen, as it has in most of Rome).
The intermediary block, like the rotunda, was built of brick-faced concrete covered in marble. The rotunda's diameter and height are exactly the same, 142ft, making it larger than any dome built in the next 1800 years. The dome springs 71ft above the floor. This means that a sphere of 142ft diameter would fit exactly inside the temple.
The rotunda rests on an immensely solid travertine and concrete ring 24ft wide and 15ft deep. It has eight load-biering piers that form the building's framework, between which are curved or rectangular exedrae (recesses) each screened by two yellow Numidian marble columns, that may have once housed gods statues.
The piers support eight arches which run through the wall's core from inside out, part of a complex system of relieving arches that buttress the upper walls against the outward thrust of the dome.
The dome itself is built of concrete with an oculus (eye) opening 27ft at the top that gently illuminates the whole temple, drawing the eye up past the coffered roof to the sky, abode of the gods, far above.
The upper parts of the dome are made of progressively lighter materials, with very light porous pumice stone being used at the top around the oculum. The 140 coffers of progressively diminishing size, arranged in five tiers of 28, also help to reduce the dome's weight while adorning its interior.
Only a small section of the original decoration of the Pantheon has been restored, but it has retained more of its original decoration than any other Roman temple, and the overall effect is still very lavish.
The Pantheon impress not only as a tremendous feat of engineering but also because it gives us a vivid idea of what a Roan temple may have been like. Its mathematically perfect proportions also elevate the spirit of visitors as they look up into the huge airy dome of this temple to all the gods.