Copper alloy dodecahedron (Roman)Original Source: CORBRIDGE ROMAN MUSEUM
All across Europe, from Hadrian's Wall in England to Avenches in Switzerland and even as far as eastern Hungary, people have found these unusual artefacts, known as Roman Dodecahedrons. There are no ancient writings or images of these objects, and their use is a mystery.
116 of these objects have been discovered, and they all seem to follow a pattern: hollow regular twelve-sided (or dodecahedral) shapes made of cast metal; they feature knobs on the vertices; and different sized holes on each face; they vary in size between 4-11cm.
This one, found at Hadrian's Wall and now at Corbridge Roman Museum, is fairly plain, but others feature rich ornamentation. They were evidently costly and difficult objects to make, which suggests they had a very special use, but so far, no-one has worked out what exactly.
The context in which they have been found varies massively. They have been discovered in Roman military camps, public baths, temples, theatres, and tombs, all dating between the 2nd and 4th centuries CE, and often in areas where Celtic tribes interacted with Romans.
Despite their distinctive appearance and evident widespread use, there are no Roman writings that mention these objects or images that depict them. Perhaps they were so-everyday that nobody thought to mention them, or so-specialised that very few people were familiar with them.
Some of the various theories as to their use include children's toys, gambling games, or fortune-telling devices - perhaps they were thrown and their faces read like that of dice. However, experiments with reproductions show they are difficult to roll.
Traces of wax have been found on some examples, which has led people to suggest they were candle holders. Others say they are simply talismanic objects, created for symbolic meaning and ritual purposes. However there are other, more controversial, theories…
Some have suggested that they may be surveying devices. If you hold the dodecahedron up to your eye, you can use the different sized holes to sight objects and estimate range or size. But with no standardisation, they wouldn't be much use.
According to one theory, they are sundials - a dodecahedron would be placed in a specific location, and on a certain date, the sun would align with two of the holes. This theory accounts for why they are largely found in northern Europe, where the growing season is short.
One truly inventive theory was put forward by a knitting hobbyist; that they were used to make gloves. This theory tries to explain why they're largely found in cold northern Europe, and why they are absent from writings on architecture, farming, and divination.
Wool would be spun around the knobs in a specific pattern, and as each finger was knitted, it would be pushed into the corresponding hole. The different-sized holes are for different-sized fingers, and the different-sized dodecahedrons are for different-sized gloves.
Unfortunately, there's simply no evidence for knitting until at least 1,000 years after the creation of these objects. Still, the observations made by archaeologists, historians, farmers, and knitters may one day help solve the mystery of the Roman Dodecahedrons.
There may be problems with the knitting theory, but it's still interesting to see it in action. Take a look at this experiment carried out with a replica Roman Dodecahedron.