Carthage employed liquid cooling system for chariot races inside the city’s circus

Posted By: Dattatreya Mandal

Chariot racing was massively popular in ancient Rome; so much so that the world’s highest paid athlete and the first billionaire from their ranks possibly pertained to one Gaius Appuleius Diocles. According to classical studies professor Peter Struck (at University of Chicago), the ancient charioteer’s accumulated prize money equated to 35,863,120 sesterces, which is equivalent of around $15 billion or £9.6 billion. But while popular culture (including Ben-Hur) has presented the Roman penchant for brutal spectator sports, their long-time ancient rivals were also interested in chariot races fueled by skilled competitors and roaring crowds. We are obviously talking about Carthage – with the Circus of Carthage being the largest sporting arena outside Rome, built solely for such grand events. And now archaeologists have come across an advanced technological ambit that rather complemented the exhilaration of chariot races, and it entailed a nifty liquid cooling system that aided both horses and chariots.

For long historians were puzzled by the ‘efficiency’ of chariots (relating to both the horses and the vehicle) in Carthage, since the city-state was located in North Africa, traditionally known for its hot and arid climate. Simply put, even horses could have fainted mid-race in such rigorous conditions. But as a result of a recent excavation at the site of Circus of Carthage, experts have now identified the use of a special water resistant mortar in one of the structures of the stadium.

The structure in question here pertains to the spina, the crucial median strip of the circus – at the end of which the charioteers made their dangerously calculated turns. According to Frerich Schön of Tübingen University, the water technology specialist who first spotted the material, the hydraulic mortar was created by combining lime with crushed ceramics. Taking advantage of the material’s water resistance, the spina in itself was arrayed with water basins. So the structure mitigated any signs of dampness, while specially employed men (known as sparsores) were given the task of sprinkling water (from the basins) on the chariots and the horses as they rapidly passed by the spina.

Topographical measurements being conducted at the Carthage circus site. Credit: DAI Rom / Ralf Bockmann

Now from the practical perspective, the job of the sparsores must have been quite unenviable since they had to dip clay amphorae into the basins and then quickly sprinkle the water on the wildly moving horse-drawn vehicles. Suffice it to say, their positioning was crucial and pretty dangerous, as these men had to be on foot (probably at the level of the arena) while deftly sprinkling water on to the fast rotating chariot wheels.
Interestingly, the use of water basins atop the spina was not just limited to the Circus of Carthage. In fact, it was quite a typical feature in many of the Roman circuses, while being also depicted on an ancient mosaic from Carthage. However the presence of the aforementioned water resistant mortar is certainly fascinating – since it alludes to how the Carthaginians employed advanced engineering and cooling techniques (beyond visual depictions) that were quite similar to their Roman counterparts.
Lastly, concerning the actual physical ambit of the Circus of Carthage, we shall take the comparative route by presenting some figures relating to Circus Maximus, the largest sporting stadium of the ancient times. To that end, the oval-shaped Roman circus with a capacity of 150,000 people, had gargantuan dimensions of 620 m of length (2,033 ft or 678 yards) and about 140-150 m (492 ft or 159 yards) of width (by the time of Augustus). The inside track, covered in sand, boasted an area of 43,000 sq m or 465,000 sq ft – which is equal to more than eight American football fields. Now the length of the Circus of Carthage was judged to be around 500 m (or 1,640 ft) – as gauged by geophysical explorations done in the 1970’s. Moreover, it’s internal width equates to around 77 m (253 ft), without the stands. Thus the total internal area of the Circus of Carthage could have equated to around 38,000 sq m or 408,000 sq ft, which is still more than seven American football fields combined!

The tricky bend around the ‘spina’ of the ancient circus.