Sad, but this is what I did this weekend . . .
During the 13th century, the counts of Troyes were busy buying back fiefs they had previously granted to vassals, in a successful attempt to make all castle-holders direct liegemen of the count. One charter states that a certain knight agreed to the sale of his holdings for "500 pounds in cash". This charter is dated 1221, so it's completely relevant for an Ars Magica saga. The only actual coin in 13th century France was the denier, equivalent to the English penny in the conversion scale of 1 pound = 20 shillings = 240 pennies. Thus, 500 pounds in cash equals 120,000 pennies.
I wondered how large a pile of coins that was, what they put it in to move it, and how many containers it would that take.
Two types of Troyes deniers existed, the larger being 19mm in diameter, weighting 1.54 grams, and being 1/3 as thick (approx.) as a US penny (which is 1.55 mm thick).
I've found a wealth of information about medieval chests, the most common type of medieval furniture, but can't find any specific dimensions. An SCA site has plans for creating a "medieval hutch", which is 16" in heigth, 24" in length, and 13" wide. I suck at math. I think that means that such a hutch would have a volume of 4992 cubic inches, which equals 81,804 cubic centimeters. (I know that I have not taken into account the thickness of the boards used to make the hutch.)
A coin with a diameter of 19 mm and a thickness of .5 mm has a volume of 567 cubic mm (rounded off) or 57 cubic centimeters (rounded again). Is this right so far?
So said hutch would hold 1435 coins (81,804/57), I think.
If these calculations are right, it would take 84 hutches to hold 500 pounds in cash. That's several wagon loads of hutches, I'd imagine.
I also found measurements for a medieval coffer, or strong box. Using the same calculations, based on its size of 18 cm high, 35 cm long, and 20 cm wide, it has a volume of 12600 cubic centimeters, and would hold 221 coins. It would take 543 coffers of this size to move the coins.
How about barrels? What are the dimensions of a medieval barrel? A common barrel? I could not find adequate information regarding this. Would medievals move money in a barrel?
I'm imagining a scene where the characters come across a group moving 500 pounds from one area to another. What would the group consist of? Knowing how many coffers/hutches/barrels it would take would be useful.
Thanks in advance,