The Mystery of the 2nd and 3rd Century Roman Dodecahedron

Posted by Chris Parker
Apr 12 2007

Sometime back we posted a brief article on the Blog concerning an interesting piece of ancient Roman metallurgy called a “dodecahedra”, whose use and function were unknown. It doesn’t strike the eye as an ancient piece looking instead rather like a piece of modern art.

Mr. Campbell found one of the items in his garden, as he describes below, and he forwaded photographs, two whch are reproduced on this page. If anyone has additional ideas about the function of the objects or has questions for Mr. Campbell, please contact us at and we will pass it along to Mr. Campbell.

Click Here to Read Article

3 Responses

  1. Falcon (C.R.) says:

    Fascinating artifacts, and truly indicative of how sophisticated the “ancient” world was.

    As for the exact purpose of the dodecadra (which Wikipedia lists under the name “dodecaeder”), I haven’t the foggiest.
    The shape and form appears to be familiar (one of those “on the tip of my tongue” things), but I can’t quite put my finger on it.

    My first instinct was that it was part of the world’s first Erector set.
    But somehow I doubt it.

  2. Administrator says:

    From Richard,

    Just read your artefacts page about Roman dodecahedra – and the possibility that they were “official” sizing guides for coins.

    UK coins of precious metals were at one time weighed to ensure nobody filed the edges to keep a bit of the gold. Clipping was also a problem.
    These size guides may have allowed an accurate gauge for this purpose.

    Could they be checked against coin collections?

  3. In my website yoy wil find a new theory for the use of the dodecahedron, together with experimental support. Shortly summarized, my new theory can be described as followed: 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. The sowing date of winter grain is important for the achievement of optimal produce. Therefore I anticipate that the dodecahedron would only be used in autumn time.

    The functioning of the dodecahedron as a measuring device is based on the angle of the sun on the highest point of the day. In a calendar year, the earth travels completely around the sun (365 ¼ day). The angle of the earth opposite the sun changes during the year in a sinus rhythm. The sun gets to the highest position around June 21, when the sun reaches the tropic of Cancer (degree of latitude N 23°.27′) and the lowest point will be reached around December 22, when the sun reaches the tropic of Capricorn. (degree of latitude Z 23°.27′).
    The vernal equinoctial point and the autumnal equinoctial point are at respectively March 21 and September 23, when the sun has reached the level of the equator. The angle which the sunlight makes with the earth is subjected to the degree of latitude where one is.
    As an example, take the city of Maastricht, located at N 50°.52′. At March 12 and September 23, the largest angle which the sunlight makes with the earth in Maastricht, is 90° – 50°.52′ = 39°.08′. On June 21, it is 90° – (50°.52′-23°.27′) = 62°.35′ and on December 22, it is 90° – (50°.52′+23°.27′) = 16°.41′.
    When one is able to determine the angle which the sunlight makes with earth, one is actually measuring the date quite accurately. According to my hypotheses, the use of the dodecahedron is based on this knowledge.

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