Close to Naples lies the town of Boscoreale. It’s an ugly place that’s not really worth a visit, but it does have a museum, located in a rather unappealing neighbourhood. It houses a decent collection of artefacts retrieved from archaeological excavations conducted in the area, including a number of objects retrieved from Pompeii, which famously got smothered in ash from the eruption of the Vesuvius in AD 79.
A funerary relief
One of the most interesting artefacts in the museum of Boscoreale is depicted at the top of this article: a damaged gravestone that once belonged to a certain Popidius Nicostratus, whom the museum refers to as a Pompeian. It probably dates from the first century AD.
The inscription reads, in Latin:
Popidius sibi et
This is a fairly standard form of Latin inscription, which can be translated as: “Nicostratus Popidius (dedicated this relief) for himself and Popidiae Ecdoche, his concubine, and his (family).” Both Nicostratus and Ecdoche are names of Greek origin, so they are perhaps of Greek origins, maybe even former slaves that once belonged to someone named Popidius? The museum’s description sadly doesn’t provide any further information.
The relief depicts the tools of Nicostratus’ trade: at left, we see an instrument that the Romans called a groma, while toward the right we see what is most likely a plumbline.
The groma was essentially a pole with a bracket device fixed to the top, on which a squared cross was mounted (a surveyor’s cross). At the end of each element of the cross a plumbline was suspended to ensure that the pole was straight, similar to how we would use a level. The pole would be driven into the ground with a spade to secure it.
Using a groma, a Roman surveyor could lay out the ground plan of a Roman military camp or even an entire city along a regular plan. The point where the groma had been driven into the ground would be where roads intersected. The main roads in either a new Roman city or a camp were the cardo and decumanus. The cardo was the road oriented north-south, while the decumanus ran east-west.
But Popidius Nicostratus might not have engaged much in laying out new cities or camps, especially since back then, like now, Campania already featured a large number of settlements. More likely, he would have been engaged mainly in divying up agricultural land into plots based on an orthogonal grid of cardines and decumani. His fine instruments, immortalized in the relief, would have ensured measurements were accurate, so that all got the land that they were entitled to, nothing more and nothing less.
The groma itself would have been made from wood and other perishable materials, which in general have left little trace in the archaeological record. Fortunately, some examples have been unearthed, including at sites in Egypt and in Pompeii. This relief, with what seems to be a detailed and accurate depiction of a surveyor’s tools of the trade, provides valuable information that aids in reconstructing and understanding this ancient instrument.