Having presented that prolog, the author explains why this matter concerns him:
The easiest way out is to reiterate that it's only a game and isn't supposed to be totally realistic. What's realistic about fire-breathing dragons or alignment languages? How does that accord with the laws of biology and physics? There are quite a few of us out here in the boondocks who feel perfectly comfortable with basilisks, fireballs, illusions, the fact that a spell called "continual light" produces continuous light with nothing intermittent about it, and even the rule that clerics can't use edged weapons, but who balk at the idea of a world where platinum, gold, electrum, silver and copper all weigh precisely the same for a given volume. And if we do say that all coin metals weigh the same, we are still faced with the volume question.The bulk of the article that follows then concerns not so much the weight of individual coins, which Godwin admits would give the referee a nervous breakdown to track, but with the size of coins. His interest in this question is in how many of a given coin will fit into a given container. So, if a chest is 18" x 30" x 18" in dimension, how many gold coins can it contain? How many silver? What about a mix of gold and silver? By recourse to formulae involving the specific gravities of each metal, Godwin is able to offer a small table that gives the weight, volume, and thickness of typical coins of precious metal in AD&D. Armed with this table and the size of any container, the referee can, with comparative ease, determine how many coins of any type can fit within it.
As these kinds of articles go, "How Many Coins in a Coffer?" isn't very math-heavy. Godwin kindly saves most of the math for himself, but, even so, the idea of having to spend much time calculating how many silver pieces actually fit into an adventurer's saddlebags seems a needless complication. Working the other way -- figuring out many and how large the containers holding a given volume of treasure must be -- is not better in my opinion. But then I prefer to keep most things in Dungeons & Dragons fairly abstract, from hit points to experience points to encumbrance. Worrying about such things has never been an obsession of mine (I'd prefer to obsess about other things), but, back in 1983 and beyond, such obsessions became commoner in the pages of Dragon. The drive toward "realism," whether in encumbrance, weather, linguistics, population density, or some other area, was the tenor of the day and Dragon's content reflected that.