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Roman dodecahedra

The enigma of the Roman dodecahedra

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The Roman dodecahedron is a small, hollow object made of bronze or (more rarely) stone, with a geometrical shape that has twelve flat faces. Each face is a pentagon, a five-sided shape. The Roman dodecahedra are also embellished with a series of knobs on each corner point of the pentagons, and the pentagon faces in most cases contain circular holes in them.  More than 200 years after they were first discovered, researchers are no closer to understanding the origin and function of this mysterious object.

The Roman dodecahedra date from the 2nd or 3rd centuries AD, and typicall range from 4cm to 11cm in size. To date, more than one hundred of these artifacts have been found across Great Britain, Belgium, Germany, France, Luxembourg, Netherlands, Austria, Switzerland, and Hungary.

An incomplete cast copper alloy dodecahedron

An incomplete cast copper alloy dodecahedron (1 – 400 AD), discovered by a metal detectorist in Yorkshire,  England ( Portable Antiquities Scheme / creative commons).

The great mystery is: how do they work and what do they do? Unfortunately, there is no documentation or notes about them from the time of their creation, so the function of these dodecahedra has not been determined. Nevertheless, many theories and speculations have been put forward over the centuries: candlestick holders (wax was found inside one example), dice, survey instruments, devices for determining the optimal sowing date for winter grain, gauges to calibrate water pipes or standard army bases, staff or scepter decorations, a toy to throw and catch on a stick, or simply a geometric sculpture. Among these speculations, some deserve attention.

One of the most accepted theories is that the Roman dodecahedron was used as a measuring device, more precisely as a range measuring object on the battlefield. The hypothesis is that the dodecahedron was used for calculating the trajectories of projectiles. This could explain the different sized holes in the pentagrams. A similar theory involves dodecahedra as a surveying and levelling device. However, neither of these theories has been supported by any proof and exactly how the dodecahedron could be used for these purposes has not been fully explained.

One of the more interesting theories is the proposal that dodecahedra were astronomic measuring instruments for determining the optimal sowing date for winter grain. According to G.M.C. Wagemans , "the dodecahedron was an astronomic measuring instrument with which the angle of the sunlight can be measured and thereby one specific date in springtime, and one date in the autumn can be determined with accuracy. The dates that can be measured were probably of importance for the agriculture". Nevertheless, opponents of this theory have pointed out that use as a measuring instrument of any kind seems to be prohibited by the fact that the dodacahedra were not standardized and come in many sizes and arrangements.

A Roman dodecahedron found in Bonn, Germany

A Roman dodecahedron found in Bonn, Germany. Credit: Hadley Paul Garland / flickr

Another unproven theory claims that the dodecahedra are religious relics, once used as sacred tools for the druids of Britannia and Caledonia. However, there is no written account or archaeological evidence to support this view. Could it be that this strange item was simply a toy or a recreational game for legionnaires, during the war campaigns? Some sources suggest they were the central objects in a bowl game similar to that of our days, with these artifacts used as markers and the players throwing stones to land them in the holes within the dodecahedra.

Statue 'Dodecaëder' in Tongeren

Statue 'Dodecaëder' in Tongeren, highlighting the mystery of the Roman dodecahedra ( Wikimedia)

Another discovery deepens the mystery about the function of these objects. Some time ago, Benno Artmann discovered a Roman icosahedron (a polyhedron with twenty faces), misclassified as a dodecahedron on just a superficial glance, and put away in a museum's basement storage. The discovery raises the question about whether there are many other geometric artifacts of different types – such as, icosahedra, hexagons, octagons – yet to be found in what was once the great Roman Empire.

The Roman icosahedron found by Benno Artmann

The Roman icosahedron found by Benno Artmann ( georgehart.com)

Despite the many unanswered questions, one thing is certain, the Roman dodecahedra were highly valued by their owners.  This is evidenced by the fact that a number of them were found among treasure hoards, among coins and other valuable items.  We may never know the true purpose of the Roman dodecahedra, but we can only hope that advances in archaeology will unearth more clues that will help solve this ancient enigma.

Featured Image: A Roman dodecahedron. Source: BigStockPhoto

References

Roman dodecahedron – Wikipedia. Available from: http://en.wikipedia.org/wiki/Roman_dodecahedron

The Roman dodecahedron – Legends and Chronicles. Available from: http://www.legendsandchronicles.com/ancient-artifacts/the-roman-dodecahedrons/

Roman dodecahedra – George Hard. Available from: http://www.georgehart.com/virtual-polyhedra/roman_dodecahedra.html

Has The Roman Dodecahedron Mystery Been Solved? – Red Ice Creations. Available from: http://redicecreations.com/article.php?id=30435

Has The Roman Dodecahedron Mystery Been Solved? – Gralien Report. Available from:
http://www.gralienreport.com/ancient-mysteries-2/man-solved-roman-dodecahedron-mystery/

The Roman Pentagon Dodecahedron: An Astronomic Measuring Instrument for Determining the Optimal Sowing Date for Winter Grain – By G.M.C. Wagemans. Available from: http://www.romandodecahedron.com/the-hypothesis

By Federico Cataldo

Comments

Just yo hopefully establish a bit of credibility here I will begin by saying, I may not have an ancient article website, and my published area of research is in medicine not archeology. I am however, highly educated and have had a great deal of interest in archeology since childhood and that became focused in the area of paleoanthropology while in college and has continued these 42 years since. For this comment however, I don't believe the breadth and depth of my education gives me a great deal of help. What I do believe gives me a, possibly, unique insight regarding these artifacts is that I'm the father of three daughters for whom I always enjoyed building things. I think it just might be possible that there is no documentation about this article because it was designed for a much simpler purpose than war, navigation, currency, or any of the other things that make popular findings. I believe the dodecahedrons could have been made as links in a decorative chain. The larger and smaller holes could have served the double purpose of allowing finger or tool tip access so a small bit of softer metal rod could be pushed through from one smaller hole of one link to the next. Then, a small tool could have been inserted and both ends of the rod tapped to flatten the tips and hold the links together. It's a very easy to make (if you aren't the person who is building the dodecahedrons!) and very decorative chain for girls of all ages. Also, once the chain is made, it can be stretched across window or door to produce a pleasing, and sometimes eerie song.

the hexagon and octagon ones were not found in roman empire because visitors who brought their own specific ones from their own country of producing, took them back home when they left. But word did spread when they were first thought of, made /forged; word got around, the idea of them for those /that use(s) caught on. Like a new idea these days that grows when a large company buys someones, new idea or invention. I wonder why they are not made of iron ? or just also carved from rock, because rock would, certainly shatter ! And not made of metal--just in case one dropped it. No..
Metal is a clue for it's purpose, Longevity especially, and endless reuse(s) Perhaps used for, trades also :)

It is strange why there are tiny circles on the flat surface at each knob.. that bras one. It can be figured sensibly that each detail has a function. not looks or decor, the whole thing had a rather major use, so why not every part, aspect, have a function too, multi uses maybe.. no candle holder, no heater, not for military. for holding string, linen strands for sewing is good possibility, But really one needs to be found with it's function present, a drawing, painting, mosaic, carving.. Since there were Olympics, could it be, for shot put.?

..candles came in various widths..these are travelers candlestick holders...like modern day flashlights !

yeah, right.. It, can't at all, generate heat......

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