What about sundials in antiquity?

Until recently, I associated sundials with castles and palaces for the rich in the 16^th and 17^th centuries and it never occurred to me that they already existed in antiquity. Meanwhile, I learned that they were known in Egypt around 1500 BC and after that in Babylon!

My first encounter with an antique sundial happened when I visited the site of Cnidos in southwestern Turkey. Here, I found such a sundial from Hellenistic times still in place. This was a most thrilling experience. Imagine standing in front of a time-telling mechanism that is more than 2,500 years old! It was missing the gnomon, the metal needle that is supposed to project its shadow onto the concave dial surface but some creative visitor had inserted a thin twig instead to reproduce the very principle. This type of dial is known as spherical or hemicyclium.

My next encounter with a sundial happened at the exhibition about Carthage that was organized in Leiden (Netherlands) in 2015. This sundial was made especially for the city of Carthage after 8 AD when the month of sextilis was renamed August in honor of Emperor Augustus. This example is, however, of an entirely different kind called scaphe or bowl sundial. The bowl is resting on its side and the sun is shining through a hole in the bowl’s top side highlighting one of the eleven timelines drawn on the inner side of the opposite part of the bowl. The fan of eleven lines marks the twelve hours of the Roman day, which were longer in summer than in winter.

After all, it seems that sundials are not entirely uncommon to the Greeks who saw them as an object of prestige mainly for public use. They were remarkably precise and very accurate, particularly those found on the island of Delos. The Romans seem to have merely copied the Greek models and used them in private life. They cared more for the philosophical attributes rather than for reading the time and they used the dial’s inscriptions and iconography as symbols.

These days, an intact and inscribed sundial has been discovered at the edge of the theater in Interamna Lirenas, near Monte Cassino, in Italy. This was not its original place as researchers believe that it was left behind by people who looted the area in search of building materials.

[Picture from Archaeology News Network, Credit: Alessandro Launaro]

The lettering and the style of the inscription indicate that the sundial dates from the mid-first century BC or later, in any case at a time when the city of Interamna had acquired Roman citizenship.

The Latin text tells us that the piece was commissioned by a certain M(arcus) NOVIUS M(arci) F(ilius) TUBULA [Marcus Novius Tubula, son of Marcus], who held the office of TR(ibunus) PL(ebis) [Plebeian Tribune] and paid for the sundial D(e) S(ua) PEC(unia) (with his own money). The otherwise unknown Marcus Novius Tubula may have used the sundial to celebrate his election as a Plebeian Tribune of Rome.

The Interamna sundial very closely resembles the Hellenistic one from Cnidos, which confirms that the Romans did not add much if anything to the existing Greek examples.