some random speculation for you regarding the question of why clocks with roman numerals use IIII instead of IV, while they use IX and not VIIII in the case of nine.
One possibility is that, while the IX and XI are really close to being upside up, the IV and VI are definitely upside down. Maybe the IV and VI were just harder to distinguish that way.
Or the Miner’s Guild was in it with the Smith’s Guild who sold to the clockmakers by weight, and after a long running dispute that was occasionally bloodied by horse sniping, it ended up in a Baker’s Guild-brokered compromise that the Miners and Smiths got the IIII, but the Clockwrights got IX.
My Rapport pocket watch has IIII, vice IV. In fact, I think that if you were to do an image search of pocket watches or grandfather clocks (time pieces which usually feature Roman numerals), you won’t find IV on many of them - if at all.
Is it possible that clock makers use IIII to keep the numerals even?
What I mean is that there are four numbers comprised of I’s, four of V’s and I’s, and four of X’s and I’s. To use IV for the number four would thow off the entire balance.
Wiki has it right and Cecil … well he kinda alludes to it when he says “the modern subtractive method (IV)” but doesn’t state it outright for some reason: the Romans didn’t use subtractive notation, constructions such as IV and IX are relatively modern inventions which the Romans would not have recognised.