A newspaper article the other day talked about decimalization and the brief trauma it wrought on British society. Decimalization, as I'm sure you know, is the event in 1971 when the UK switched from a monetary system that broke a pound into twenty pieces and each of those into twelve smaller pieces. Since then, there are one hundred pence in a pound, basta.

In this article was a big photo of a couple of babushka'd old ladies standing before an informational sign which helped you convert between the old and the new currency. It was neatly designed, and had two columns of figures, running like this (I draw your attention to the headings):

Now, I was perplexed by this. I knew that the new system, £p, was pounds and pence. I knew that "s" had to be shillings, and I knew there were a load of other coins in the old system: halfpennies, farthings, florins, crowns, et cetera. So I was scratching my head as to what could be the "d" in "£sd." Some other coin than the penny? But what?

Turns out to be more peculiar than that. "£sd" is short for "librae, solidi, denarii," and there you get your explanation for that crazy pounds sign—a hashed "L." "Libra" is a Latin word for "pound" as a unit of weight, and the other two are Roman coins.

There are at least two kinds of slashes in typography, one (the virgule) more of a prose slash, as in "let's have pudding/dessert", and the other (the solidus) more of a fraction slash (as in 3⁄4). The name "solidus," as you now realize, derives from the old British notation for shillings and pence, as in figures like 3⁄6 (the original price of a John Le Carré book I just bought, now valued at £2).

Does the US dollar sign have an origin in some Latin term? Unclear. Wikipedia lists no fewer than eight origin myths for the dollar, all a bit dubious. It seems that the sign itself does predate the republic.

Finally, please enjoy this sign appearing in St. Andrews, Scotland, just an hour or two from where I write.