arks, with the name of the current annual Consul were stamped on every few bricks that were manufactured. The terms of office for these officials are known and the dating of the bricks can be fairly precise.1 The name of the architect is not known. This is not because such names were not preserved. The Pantheon was constructed on the site of another temple that had been built by Augustus Caesar's architect and minister, Agrippa. and had twice been destroyed by fire. The name Agrippa was, confusingly, included in Hadrian's inscription over the door but it is certain that he was not the architect.2 Hadrian himself was an architect, further evidence that the profession was held in high enough esteem to merit remembering the designer's name.3 But the name of this man has been lost.
In the five centuries between the time the building was put up and the time it was reclaimed by the Catholic Church to serve as a church, the emperors had changed their capital from Rome to Constantinople. The city of Rome became an impoverished small town in which the buildings of the Romans were allowed to fall into ruin. But the Pantheon survived and once it was reclaimed by the Church, as Santa Maria Rotonda, the combination of its solid construction and centuries of effort by "drain-cleaners and rooters-out of trees and vegetation combined to preserve it until proper help was brought in modern times."4
The Pantheon as it exists today is a large drum-shaped cylinder with a rounded dome. There is a transitional block at the front of the building and a temple portico or porch with eight Corinthian columns supports a triangular pediment. The height of the crown of the dome from the Pantheon's floor measures exactly the same as the interior diameter of the building. The walls are divided by cornices into two zones on the interior and three on the exterior. The interior is lit by an opening at the crown of the dome. The structure required ext...