Augustus’ Timepiece

A short walk from us brings you to the Piazza Colonna and, behind that, Piazza Monte Citorio.

Palazzo Montecitorio, the Chamber of Deputies

As you walk through the piazza, you will notice some small bronze markers set into the pavement, as seen in the picture at the top of this post. You might wonder what they are — and you only have to look up to find a clue to the puzzle. What you’ll see is the horlogium, Augustus’ timepiece.

In front of Palazzo Montecitorio (where the Italian Chamber of Deputies is located) stands an ancient Egyptian obelisk of red granite. It was brought to Rome by the Emperor Augustus in 10 B.C.E. The prevailing theory is this obelisk was brought over not to simply be an ornament, but to serve as part of a giant sundial.

The obelisk, alas, no longer stands where it was originally erected (which was close to the original location of the Ara Pacis). You can see some presentations of what we think it may have looked like, and how it worked, at James Grout’s site.

Palazzo Montecitorio by Giovanni Paolo Pannini, c. 1747 — before the obelisk was moved here

The long-forgotten and badly broken obelisk was discovered in the 18th Century when some buildings behind Piazza Monte Citorio were pulled down. The obelisk was then moved to its present location, and re-assembled.

Engraving showing the moving of the pieces of the obelisk, by Vasi, c. 1792


Engraving of the Piazza Monte Citorio, showing the obelisk now standing in the piazza

Missing chunks of the obelisk were patched with red granite, as can readily been seen today.

The Obelisk of Monte Citorio, with its red granite patching visible

Although my understanding is the obelisk no longer functions as a sundial, since it has been moved from its original location, the bronze markers were placed in the pavement around it.

Some of the original markers, along with greek descriptions, can be found under a nearby building. That’s yet another sight I’d like to visit, when it’s finally time for me to go back to Rome. COVID has made time stand still… even for the Eternal City, where Augustus’ timepiece still stands.