Coin weights

[PeterD]

My curiousity was aroused by these two exagii (sing. exagium), or coin weights, so I bought them in spite of knowing nothing about the subject. They apparently date to the 3rd century A.D. and are Roman. They are simply small lumps of copper/bronze with Roman numeral 3 inscribed on them. The rectangular one weighs 4.48gms and the square one 4.61gms.

Anyone know how they were used? The weights are approximately 1/70 of a Roman Pound so could conceivably have been used to weigh a single gold aureus. But why the number 3?

[Pscipio]

Where did you get that date (3. Century AD) from and what is it based on?

Lars

[Manzikert]

Hi Peter

The inscription on the square one is a N which stands for nomisma, the Greek name for the solidus, which was 1/72 of a pound (c.4.55 gm), so the weight is roughly correct.

As the solidus was introduced about 309 and the weight standard was used well up into the Byzantine period the date should really be something like 4th-10th century at least. As the inscription is from the Greek then the weight is obviously from the eastern part of the Roman/Byzantine Empire.

What the significance of the three strokes on the rectangular one might be (apart from a badly inscribed N ) I don't know, but if the weight is the same, then the use could well have been the same, as a nomisma weight.

Best wishes

Alan.

[PeterD]

Alan,

Thanks for that information. Of course, silly me, 1/72 was the solidus, 1/60 the aureus. My two weights work out at 1/73 and 1/71. Presumably they were used to check individual coins to check if the were genuine, rather than to accurately weigh them.

Lars, the information came from the seller with no justification, hence my question here.