Pound Wise

 

Roman Bronze As (pound) coin
Obverse - head of Janus. Reverse - Prow of a ship

You've likely heard the expression "penny wise and pound foolish" - meaning that you can pay attention to the details and still miss the big picture. This, of course, makes more sense when you understand that the penny and pound are units of money from the UK - not a mixture of money and weight as it first appears in the US. We are so used to decimal currency - 100 cents in a dollar - that it's easy to forget that currency hasn't always been like this. Before the radical attachment to multiples of ten, in both currency and metric measurement, usually the importance was in being able to break something into pieces of equal value.

And ten, while it's handy in so many ways, is not as good as dividing into subvalues as twelve is. 10 divides in halves and fifths, of course, but it doesn't divide neatly into thirds, quarters, sixths or eighths. Meanwhile, 12 divides evenly into halves, thirds, quarters and sixths. 

 

The ancient Romans understood this, which is why, when they moved to a coin-based system in the Republic (around 280 BCE), they set it up so that their largest bronze coin, the As was twelve times their smallest coin, the uncia. The As was made of bronze, and struck at 1 Librum (pound), equivalent to roughly 328g or 12 oz. Yes - our ounce derives from the Latin uncia - itself meaning "one [unit]." Thousands of years later, we still have roughly the same measurement in use! (Interestingly, the word "inch" also derives from uncia!)

This gave the Roman currency the ability to have other coins that were fractions and multiples of the As:

10    Decussis, equivalent to a Denarius (1/8 ounce of silver)

5      Quincussis

4      Quadrusse

3      Tressis

2.5   Sestertius (later changed to 4 As due to inflation)

2      Dupondius

1      As

1/2   Semis

1/3   Triens

1/4   Quadrens

1/6   Sextens

1/12 Uncia

1/24 Semiuncia

12 Uncia to the As - 12 oz to the pound. Which is still the metals standard today - 12 troy ounces to a troy pound. (Why it's called a "troy ounce" is a divergence for another time)

Over time, of course, the value of the coins diminished due to inflation - one of the main ways that Rome's many wars were funded was through devaluing the currency. By the time of the Caesar Augustus, the As was changed from a pound of bronze to a half-ounce of copper. What had started as a pound was now a penny! 

Caesar Augustus' changes were intended to make things less confusing, but to our modern sensibilities, it looks like a jumble of numbers. 4 copper As to the bronze Sestertius. 5 Sesterce to the silver Denarius. 25 Denarii to the gold Aureus (later renamed the Solidus). If you're familiar with British Imperial currency before the 20th century reforms, you may recognize values given in £sd - L for Libra, s for Solidi, and d for Denarii. In the usage, £1 was 1 pound of sterling silver. 1 shilling was 1/20th of a pound. 1 pence (1 penny) was a twelfth of a shilling.

From the Roman As to the British pound and its divisions into shillings and pence, the echoes of these ancient currencies resonate through the corridors of time, influencing even our present-day financial systems. While our currencies have evolved and transformed, the principles behind their divisions into units that could be divided and multiplied efficiently have left an indelible mark. The Roman understanding of divisibility, with its emphasis on the number twelve, and the subsequent adaptations through history, remind us that beneath the digitized transactions and complex economic mechanisms of today lie foundations laid centuries ago.

Even as we've transitioned to decimal systems and globalized currencies, remnants of these ancient units persist in our language, our measurements, and even in the subconscious ways we perceive value. The 'pound wise' approach, rooted in these historical systems, urges us not just to focus on the details but to grasp the broader context—a sentiment that transcends mere monetary transactions.

As we navigate the digital age of finance, let's not forget the profound influence and lasting wisdom embedded in the pound, the ounce, and the ancient systems that continue to shape our understanding of value and worth.

Sources:
https://www.monete-romane.com/roman_coins/as.html
https://www.forumancientcoins.com/dougsmith/worth.html
https://en.wikipedia.org/wiki/%C2%A3sd
https://en.wikipedia.org/wiki/As_(Roman_coin)