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The genius architects of ancient Rome


by Jason Collins

After visiting St. Peter’s basilica, the next most interesting place for me to go in Rome is the Pantheon.

It is one of the oldest buildings in the world still used for its original purpose. What was constructed by the Romans to honor all the gods (from the Greek pan for all and theion for gods), it now honors Mary, the mother of Jesus, and all the martyrs.

The current building was constructed around 110 AD or so during the time of the Emperor Hadrian, who may have had a hand in its design. The inscription in the pediment (the triangular shape at the top) tells us that Marcus Agrippa built it (circa 20 BC). The original structure built by Marcus Agrippa was most likely destroyed in a fire. However, when the Emperor Hadrian rebuilt the temple, he wanted it to reflect the original age, hence the inscription “M.AGRIPPA L.F. COS TERTIUM FECIT,” which means “Marcus Agrippa, son of Lucius, consul for the third time, made this.”

What makes the Pantheon so unique and fascinating is its concrete dome with an opening in the middle. Yes, concrete. That stuff you drive on was practically invented and perfected by the Romans. Did you know that Roman concrete is stronger and more durable then modern concrete? They also had concrete that would cure under water! This concrete dome has served as the inspiration for buildings not only in Italy, from St. Peter’s to the Duomo in Florence, but also for buildings in the United States, most famously the Capitol building in Washington, DC.

The Romans expertly designed the dome structure so that concrete is thickest at the base and then narrows as the dome rises. They also placed small jars in the aggregate towards the top to lessen its weight. The oculus, the hole in the middle, actually serves a structural purpose – a dome with no oculus would have more than likely collapsed long ago.

It is thought that the dome represented the heavens with the oculus giving a view of those heavens. Inside, the edifice still looks much the same as it did to Roman eyes, with the notable exception of the addition of an altar and the removal of pagan gods from the niches. It was this addition of an altar that probably saved this building from the fate of so many other ancient Roman buildings that were reused to build new structures or repair existing ones.

In 609, the Byzantine Emperor Phocas, presented the Pantheon to the Pope, who consecrated it as a church.

Not only is the dome an amazing piece of engineering, so is the portico with is 40 foot tall solid columns. These monolithic columns were quarried in Egypt, shipped down the Nile, across the Mediterranean, and up the Tiber before finally arriving in Rome. Perhaps during the long journey something happened to the original columns. If you look at the Pantheon from either side in the piazza, you may notice some niches that form a triangle about ten feet are higher than the pediment. While Roman ruins are spread throughout the city of Rome and Western Europe, giving hints to the size of Roman construction; the Pantheon is a still an intact work of art that speaks to Roman engineering and ingenuity.


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