# Mysterious 12-sided Roman object found in Belgium may have been used for magical rituals

#### GoldHorde

I'd go with a CALTROP used against horses (cavalry/chariots) but the differing hole dimensions do suggest a calculative purpose.

RickintheUSA

#### claudiusxander

Search youtube for some lovely people knitting gloves using these dodecahedrons. The different holes are for varying finger sizes, Also they are only found in northerly colder regions of roman empire, where gloves were necessary.
"Knitting with a Roman Dodecahedron"

#### EMM

It could be a "massage therapy" device. The holes would allow a "hot" coal or other hot object to radiate while the knobs "rolf" muscles. I expect we will never know for certain but that's my input.

#### Baryonyx

Nowadays we might say these dodecahedra look like viruses, thanks in part to those projections. (The "head" of a bacteriophage is typically rendered as an icosahedron--& the whole thing resembles a lunar landing craft!)

#### Stratovaari

As this objet has various sized holes I assume it has been used to check the sice of metal objects. Would be easy to determine what the size of a coin or a metal sphere or some other spherical object is.

#### smee

Someone has not been doing their homework. This object was the subject of study a number of years ago. It is not magical and not for knitting. It is a sighting device. The pairs of holes are used for determining distance. Line them up with the smallest closest to the eye and move your arm forward until the sizes of the holes appear to be identical. The distance from the eye is the N in the equation to determining distance. The differing sizes are used for estimating the rough distance before taking a proper sighting.

#### dcbrown

When I read Amelia Carolina Sparavigna's paper I was certain she was onto something. I figured calculating the eye distances based on the hole measurements she provided would show they were consistent with a normal arms length, and that would be a nice verification. But I did the calculations and one hole pair on each of the measured dodecahedrons didn't check out. It would need to be held 3-6 meters from the user's eye. We should expect something about 20" or less for a handheld portable device. Wouldn't a reasonable person just use smaller holes? Her theory also doesn't explain the knobs at the corners. She's definitely onto something, but it's not the whole story.

Another concern was that a much simpler device would have performed the same function better.
Consider that a single hole in an ordinary flat disk, and a cord equally divided into equal segments (by knots) would allow estimating ANY arbitrary distance as long as the approximate size of the viewed object is known. This would give a more accurate distance estimate and be much simpler to make.

But it would be possible to improve that simpler device. Fiddling with a measuring cord would be awkward if the user just needs a quick verification that his target is in range. So some means of quickly comparing actual range to a few standards (like the range of his ballista) without the cord would be desirable. The opposing holes of different sizes on the dodecahedron provide that. But it's an extra feature, not the primary function.

But if they want to keep the capability of the more accurate measuring using a cord they would want some means to wrap the cord when not in use.

Also consider that the cord could rot and be broken. If broken it would be difficult to replace in the field (a military campaign) with an accurately divided cord. A way to use an ordinary piece of cord that that somehow measures itself would also be nice.

The dodecahedron addresses these shortcomings of the simpler device. A few hole pairs are provided that can be used for quick range verification checks without a measuring cord. The large and small holes can be used to define the proper holding distance by the method of corresponding edges.

A measuring cord is provided to make arbitrary range estimates accurately. This would use those hole pairs that do not really work for the cordless method. A knotted cord would probably have been a provided initially.

The knobs or balls on the corners provide a convenient means to wind the measuring cord. This can be done without blocking the holes if adjacent knobs are used, the cord always following the dodecahedron edges.

When winding the cord this way it is naturally equally subdivided and self-measuring. Each segment of cord that is unwound is equal to one edge length of the dodecahedron. So a knotted cord is no longer essential. If the original knotted cord is lost or broken an unknotted cord can replace it. The cord would even be somewhat self-marking due to the tendency to discolor where it repeatedly rubbed on the copper alloy knobs. This makes the natural knot spacing for the cord equal to the edge length of the dodecahedron.

To measure range an object of known height (probably a man...an enemy fighter) is viewed through the hole in the dodecahedron. The user would hold the dodecahedron far enough from his eye that the height of the man appears to fill the field of view. The range is then proportional to the eye distance as measured with the cord. The actual distance in stadia or any other Roman units is irrelevant as long as the range of the ballista is known by the same method.

This is for rough range estimates with a portable device, not surveying. There are more accurate methods available when you have access to the down range position.

I think this is a reasonably complete explanation. All the features of the dodecahedron are explained and are consistent with this function.

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#### danielkblackwood@outlook.

I would like to put forward a new description of the workings of the artifact, please.
The key to the Roman Dodecahedron is perspective.
In 2019 I came to the conclusion that the artifact can be photographed from any direction and would produce a unique silhouette from each and every angle it was photographed.
I found this to be true for the shadow cast by the artifact also.
This 3D form made up of 2D images resembles an unseen radiant star pointing in any and all directions. As a big bang projecting outward or a globe projecting inward.
Its uses could include a space compass used to navigate, map, or plot in 3D space.
Further, the true form I was seeking when I made this discovery was a 3D writing system and to be honest that is also plausible.
I understand that is a lot to fathom but for now, I'm calling it perspective theory by Daniel K Blackwood.
Thank you.

RickintheUSA

#### Uncialist

I believe I have discovered the real use of the Roman dodecahedra.
They were night time clocks using candles of differing thickness for each month of a year in the different size holes in the twelve faces. A major argument levelked at this is that no two examples have the same size holes so there was no standardization. What I suggest is that each object would need holes sized to the latitude where the artifact was used as the length of night varies with the date and its latitude. The variation within each month is less than needed so that candles of the same size for each month would be sufficient to monitor the changing of four watches used by yhe Romans. A full descriptive document is available.

RickintheUSA

#### RickintheUSA

*It appears that it could be used to measure coins, but old Roman coins in that time period were not very round. They were hammered on a die, not cast, so they weren’t a perfect circle. Weight and material constitution was more important to the value of an ancient coin, not a perfectly round shape (especially since the coins were debased of their silver so much during the 3rd century). In addition, some dods had triangular and oval holes.

*Knitting tool?- interesting, but some dods are too small for this; also some holes are too small; finally, that type of 'French' knitting tube size is based on number of knobs(pins), not the opening/hole sizes.

*range finder? – prob. not, as the dods found are all different sizes, with different opposing opening/hole size ratios & no numerical markings; also, some dod hole pairs would be measuring something so close to you, you wouldn’t need a range finder or you have to hold it farther away from you than your arm could reach; also, there were other somewhat accurate range finders in use by the Romans. Finally, the device would have been found in a wider area.

(Researched Opinion below)

Could it be the original Swiss army multi-tool? Kinda…

The enigmatic object many refer to as a Roman Dodecahedron (or ‘Dod’) is of Gallic/Gaul (including the Swiss Alps)/ Germania Superior & Inferior Origin (Northwest Gallic area). It was initially produced by Gallic-descendent blacksmiths (ordered by Negotiatores/Roman arms merchants in conjunction with Roman auxiliary army arms officers) as a ‘blueprint’/spec key, procurement & (in varied instances a) maintenance tool for polearm wood weapon shafts (mainly) for the Roman Auxiliary troops (of which polearm size/specs were varied)…for region-specific tribe/area troops. Some were also used to measure tool handle shaft diameters (including oval) -see Jublains Dod.

Negotiatores/arms merchants, Auxiliary troop arms officers and mid-market woodworking (and other) merchants utilized the tool to efficiently measure/QC multiple weapon shafts in the business of procurement and maintenance. This would include the max shaft diameter at its expected point along the shaft; the (exposed) shaft taper ‘just prior’ to where the shaft joints the metal head (if applicable per weapon), & the shaft taper that will be inside the metal weapon head socket. And (if needed) for maintenance – to replace damaged shafts in workshops located inside a fort or in a related Vicus, by removing the weapon heads (most auxiliary troop weapon heads are wider at the blade than the socket and are easily removable with the dod). Some were used as a maintenance jig to mark/actively taper shafts (see Corbridge Dod). Some dods with inscribed circles around the openings were used to measure/center & mark the end(s) of pre- or post-tapered shafts (to the desired final diameters at the head joint and end of the shaft).

The Dod knobs (@ all the vertexes) served as a grip to remove the head from its shaft (usually wrap the weapon head with cloth prior), in one of multiple fashions including through a wedge opening, or used as a fulcrum with a varied lock bar, if twisting is needed…but inertia worked well with the weight of the dod (vs. the weapon head) & dropped on the weapon head for quick removal. The knobs also served as a tie-down when shaving or measuring shafts, or (in some cases) lathe tapering the end of multiple wood weapon shafts although most shafts would have been found to be shaved (vs. lathe turned) due to shaft thickness and length. The knobs also served to allow the shafts to efficiently pass through from the top to bottom of the dod, to ensure measurement caliber is acceptable - with a small tolerance (based on knob distance past the face openings).

The sizes of different dods related to the length of the weapon shaft that resides inside the weapon head sockets.

Contrary to published work comments, many dod openings DO show signs of chips/dents, scrapes and cuts (especially some of the larger opposing openings and the largest opposing openings – damage is not just from oxidation). This damage is due to the weapon heads being removed, and in some cases from using as a jig (see Corbridge dod), or ‘can-opener’ pry bar when ‘in-service’ weapon heads are broken-off at the head and wood needs to be removed in anticipation of a new shaft being inserted.

All reviewed, published interior weapon socket shaft max/min diameters/tapers (in the ancient Gaul/Gallic/Britannia areas) are consistent with the size of the dod openings & opposing openings. Because of the wide variation of thrusting weapon shapes/sizes/shaft tapering in the published Dod find areas (as is understood through the archeological record), these dods would have logically been of different sizes and had/have different hole/opening sizes and opposing opening size ratios, for procurement/maintenance of these different auxiliary troop’s weapons.

The Dods began to be used during Roman fort expansions on the frontier regions of conquered Gaul in the Rhine/Danube regions (and beyond in Britannia) when weapon procurement was localized. Auxiliary troops (as opposed to the Legion troops) used many of their own traditional weapons which had different calibers, per tribe origin. There were many different tribes in the Gallic area that were not organized as one power, thus the differences in their weapons, & the dod opening sizes (and ratio or opposing opening sizes), per dod.

Shafts (and especially at the ends at the head joint) are the weakest part of the pole weapons and a relatively constant supply was necessary (either due to training or war, etc.). The Dods ensured the quality/specs of auxiliary troop-specific weapon shafts.

Once inflation became out of control / coins being continually debased (near the late 3rd century+), the mass production of weapons was required & began, and the Dods were no longer needed as local/regional arms merchants were no longer supplying the (majority of the) weapons and there weren’t 30-40+ different sizes of polearm specs to be blueprinted for all the regions. In the coming years, the Roman empire declined & then dissolved in Western Europe.

The ancient Swiss 'Army' (multi-tool) has come a long way since then...

Richard Allday

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#### Curt Welch

I think they are a gauge for testing the spherical roundness of objects. I wrote about this idea here:

Roman Dodecahedron I suspect is a Ball Gauge

I wrote a longer post, but the system blocked me from posting it.... Ugh.

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