[Roman] Dodecahedrons

One of the items in the “Pompeii Sorceress Kit” somewhat resembles a Roman dodecahedron and supposedly suggests a cultic, ritual, or magical use for such items.

The dodecahedron with zodiac markings is in a museum in Geneva at the Cathedral of Saint Pierre. It is solid, made of lead and plated with silver, has no holes, has no knobs on the vertices, and dates to a century or two later than the hollow bronze knobby dodecahedrons. It shows up on some of the lists of Roman dodecahedrons, but it does not seem similar enough to me.

Those slashes could just be remnants of whatever blending technique was used to fix the wax pieces together prior to the lost wax casting, but all of these variations in form do sort of lead me back to the notion that maybe these were objects that were made by a metalworker who had only received a description of the object.
Some examples have inscribed ring markings that concentrically encircle the holes. Others have small circular decorations that sort of orbit the holes, and this one has inscribed marks along the edges - could it be that these are all the result of what happens when you give a bronze worker a description such as ‘a hole in each face, with inscribed lines around each hole’?

Silly little idea, but I asked ChatGPT if those dodecahedrons could have been the centrepiece of an ancient umbrella and what it might have looked like. This would explain the regional distribution, as France, Belgium, Germany, Netherlands & Britain were probably wetter than other parts of the empire.

Edit: 422 error when uploading images?

I had a “magic kit” when I was a kid, with various self-working tricks (you know, so even a kid could do them). One of them was a board with a grid of various “mystical” symbols, and your mark was supposed to make various choices to ultimately end up on one of the symbols, and then you’d open an envelope that said which one they picked. Inside the envelope, it said “Three circles”, and there were (IIRC) four different spots on the board with (different) symbols consisting of three circles, any of which they might have landed on.

Google provides me lots of links to sites that say the Roman umbraculum was most likely constructed the same as a “modern” umbrella. The Roman Catholic Church still uses an umbraculum as part of papal traditions. No parts look like dodecahedrons. Functionally, I don’t see how a dodecahedron would be useful in an umbrella. If your handle goes in vertically, it passes through the center of the dodecahedron, filling up much of that area. You could insert five spokes that stick out and down at an angle, but they wouldn’t go in far before they hit the handle stick. You wouldn’t need five spokes going up and out at an angle, so almost half the holes would serve no purpose. Nothing about it would lend toward an ability to fold open and closed. Considering the holes are normally all different sizes, why would your umbraculum specifically need five spokes all of different diameters? The dodecahedron’s form really does not suit the function of being an umbraculum part.

Culturally, only Roman women used an umbraculum. Men considered them effeminate. Yet dodecahedrons often show up in areas associated with the Roman military where few people would have been willing to carry an umbraculum. Lots of Roman women carried an umbraculum to keep the sun off their skin, yet no dodecahedrons have been found in Italy where far more likely there would have been women using an umbraculum. The distribution of where dodecahedra have been found does not match the locations where people would more likely have been carrying an umbraculum.

I don’t think anyone can upload images in their posts. Instead, insert a link to where the image is externally hosted.

Thank you for those pics Retzbu_Tox

I could see how a robust dodecahedron type object might function as a the hub for constructing the roof of a tent or something. Poles jammed into various holes, knobs onto which lines can be laced, or over which leather buttonholes can be secured, but it would be a weird solution for a problem that doesn’t really require so complex an object to solve.

I’ve seen this list of suggested dodecahedron uses on a few sites, along with arguments about how there is no proof for any of them, or they are rather unlikely, or that some are just dead wrong,

  • A specific type of dice for a game since lost to history.
  • A magical object, possibly from the Celtic religion. A similar small, hollow object with protrusions was recovered from Pompeii in a box with either jewellery or items for magic.
  • A toy for children.
  • A weight for fishing nets.
  • The head of a chieftain’s scepter.
  • A kind of musical instrument.
  • A tool to estimate distances and survey land, especially for military purposes.
  • An instrument to estimate the size of and distance to objects on the battlefield for the benefit of the artillery.
  • A device for detecting counterfeit coins.
  • A calendar for determining the spring and autumn equinoxes and/or the optimal date for sowing wheat.
  • A candle holder. (Wax residue was found in one or two of the objects recovered.)
  • A connector for metal or wooden poles.
  • A knitting tool specifically for gloves. (That would explain why no dodecahedrons were found in the warmer regions of the Empire.)
  • A gauge to calibrate water pipes.
  • A base for eagle standards. (Each Roman legion carried a symbolic bird on a staff into battle.)
  • An astrological device used for fortune-telling. (Inscribed on a dodecahedron found in Geneva in 1982 were the Latin names for the 12 signs of the zodiac.)

So would candle holders. Warmer regions tended to use lamps that burn oil or fat in it’s liquid state

Edit: however a culture that used oil lamps made of fired clay would probably make candle holders from the same material, I would think, and also would probably style them for similar usability, such as putting a handle on one side so they can be easily carried.

Some of those proposed uses face the objection that you could do the same job with a much simpler object, and some face the objection of “well, but how would they have used it for that?”. Like, for instance, a surveying tool would certainly justify the amount of craftsmanship in one of these, but how would it be useful for that? You also have to contend with the fact that they’re not entirely consistent in their traits: For instance, some but not all have clear distinctions between their faces. The ones with distinctions could be used as dice, but not the ones without.

The Asian dodecahedra vary from the Roman ones in that the holes are all the same size. It appears that one feature of the Roman ones is that the holes were deliberately made of different sizes. As I wrote above, this is a generalisation, some have every hole different, some have some overlap in sizes. I suspect this is an important aspect of the design. There was a desire to, at least symbolically, make each face distinct - although being able to tell one from another visually wasn’t important. They weren’t a useful die. Nor measuring instrument.

The trouble with a dodecahedron is that there are not exactly a large number of Platonic solids, and only so many ways to make them. There are without doubt going to be parallel paths to the same result.

Certainly not everything that’s a dodecahedron is related. The Zodiac-sign die, for instance, probably isn’t. But “hollow dodecahedron, with a circular hole in every face, and a knob at ever vertex” sounds pretty specific, especially since we haven’t found other Platonic solids like that (though there’s an icosahedron without the big circular holes, and an irregular solid, both of which do have the knobs).

The Romans used plenty of bronze oil lamps, as I’ve linked to before, so that objection doesn’t work.
I mean, they did also make clay candlesticks. However, their actual existing candlesticks, bronze or clay, look nothing like dodecahedrons. They look just like later candlesticks.

I think you absolutely nailed the juxtaposition of puzzling factors here; the dodecahedra are elaborately crafted in many cases, and have features - in particular the varying sizes of hole - that appear to have some deliberate purpose to them. It’s easy enough to cook up an idea that explains some factors, but the ideas that fit best in one way tend to be absurd in others.

Every time I think hard about these things, I change my mind. I’m now back to thinking maybe they were intended as some sort of retort - a lot of roman glass medicine/cosmetic bottles were very small and tapered in shape and would not stand up on their own; a dodecahedron with a variety of different sized holes would work as a stand or retort for a variety of different-sized small bottles; it would also allow them to be warmed by standing the apparatus in a pot of warm water, to melt and loosen the contents of the bottle, allowing it to be applied in small dabs with a brush, yet keeping both hands free. Here is an example of such a glass bottle: https://p1.liveauctioneers.com/5584/243868/126452380_1_x.jpg?height=310&quality=70&version=1649795396

Except the problem with this is that it’s a highly specific use case, and although there are numerous examples of tapered bottles, the majority of Roman glass vials appear to have flat bottoms and could stand up on their own.

Echoing that they might not be rare based only found specimens. Not a direct correlation of course, but for example there are only about 40 T-rex skeletons vs the just shy of 2 billion that once lived. Compare that to the 120 or so found dodecahedrons - that suggests to me that there are probably many more that have yet to be unearthed.

Or maybe, like copper wire collectors today, many of them were melted down after their usefulness faded.

It’s easy to forget just how little stuff survives for us to study. We have lots of stuff from ancient Rome, but still a miniscule amount relative to what they produced. And since the Romans used lots of papyrus, much of what they wrote is lost to us forever.

For all we know, these things were a fad among Roman officers for some period of time: an expensive tchotchke that they displayed because they were popular.

Humans from ancient empires were cognitively identical to modern humans, which means they’re just as likely to display neat-looling useless stuff as we are, and just as likely to value something useless because it’s popular.

If they had some common use, would there not be somewhere a fresco or floor mosaic or imprinted or glazed ceramic design showing one of them actually being used?

As a rulke I distrust explaining unfamiliar objects as “religious” or “cultic” items. That was one of the favored explanations of North American “Birdstones”:

It seems highly probable that these items were handles for atlatls – spearthrowers. The long portion that has holes that look as if cords went though them would have been used to tie the handle to the atlatl, while the bulbous “eyes” were actually places for the speasr shaft to rest.

Similarly, although it’s a fictional example, in Frederic Pohl’s “Heechee” story Beyond the Blue Event Horizon the alien artifavts are thought to be “prayer fans”, because no one could come up with a more plausible explanation for the ubiquitous artifacts. Until later in the book where it’s revealed that they’re really books than can be read when inserted into an appropriate reader.

I still favor the “glove knitting” theory. It’s been demonstrated to work, explains why these are found in colder parts of the Empire, and explain the pattern of larger and smaller holes.

How? The size of the knitted thing depends on how the knobs are placed.

I’m still favoring “popular tchotchke” .