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The Mystery of Numerical Notation on the Dial Plate – 4 Is Expressed as IIII (seiko.co.jp)
26 points by mmastrac on Sept 14, 2022 | hide | past | favorite | 24 comments



This information is wrong the original number is IIII and IV notation was introduced much later.

As proof you can see that in the "portal" of the colosseum in Rome,they are numbered using the IIII notation and the colosseum is from the first century. In this photo you can see gate LIIII still standing up to this day.

https://www.flickr.com/photos/georgechamoun1984/7217597802


According to wikipedia: https://en.wikipedia.org/wiki/Roman_numerals there doesn't seem to have been a great deal of consistency about this (ie. IIII vs IV) in ancient times. I suspect that the notion that there is a single correct form is the (relatively) recent invention.


Huh...this is kinda interesting. This notation does produce a nice symmetry on the dial: four "I" numbers, four "V" numbers, and four "X" numbers. Satisfying, indeed. Roman numerals are terrible anyway, so I fully support any effort to butcher them.


Ah, the timeful symmetry of 10.5, 2.5, And 5.5 mod 12.

Roman numerals are nice because they don't steal attention when you aren't trying to read them.

General, intrusive text signage is mildly psychologically harmful.


Wikipedia says:

>Isaac Asimov once mentioned an "interesting theory" that Romans avoided using IV because it was the initial letters of IVPITER, the Latin spelling of Jupiter, and might have seemed impious. He did not say whose theory it was.

That's the explanation I've always heard.


This bit of speculation goes back at least to David Eugene Smith (1925), "History of Mathematics", volume II, page 59:

"There is a possibility that the Romans avoided IV, the initials of IVPITER, just as the Hebrews avoided יה in writing 15, as the Babylonians avoided their natural form for 19, and as similar instances of reverence for or fear of deity occur in other languages."

https://archive.org/details/in.ernet.dli.2015.201939/page/n7...


That would at least explain why they (sometimes) used IIII instead of IV, but apparently didn't use VIIII instead of IX, XXXX instead of XL etc. etc.


> In the middle ages in Europe, IIII was generally used, not IV, to express the Roman numeral 4 until around the 17th century.

This definitely stuck around much longer. I've seen plenty of wall clocks from the late 19th and early 20th century which also had the IIII instead of IV - and always wondered why some clocks from that time used IV and some used IIII (maybe it was just a retro-fashion at that time though, don't know).


I remember reading that IIII also made it easier to create the numbers in the first place. A watchmaker would mold VIIIIIX four times, the first would be cut as V, IIII, IX ; the second as VI, III, IX (the latter rotated to become XI) ; the third as VII, II, I, X ; the fourth as VIII, IIX (the latter rotated to become XII).


The site itself is interesting as well, Seiko has a fascinating history


Another mystery is why AM/PM time periods start with 12 instead of 0. Minutes and seconds are zero indexed, why not hours? I suspect it may have to do with how clocks have a 12 at the tope, despite 12 effectively being a thirteenth hour.


Yeah, "normal" people don't count from zero unless forced to.


"Denormal" people (e.g. coders) usually don't count from zero either, but when measuring distances or offsets, starting at zero makes sense (even in the real world, for instance a ruler starts at zero, and that's obvious also to "normal" people).

Anyway, where was I ...


They also don't count from 12 playing the role of zero (outside of AM/PM time).


Degrees and other circle-like things often interchange 0 and 360 depending on what "feels right" at the time.

The way clocks are built the first number is "hours since midnight/noon" depending on if it before or after 1 AM/PM heh.


That explains why the small church in the Italian village I'm from, built around 1650 IIRC, uses roman numerals for the clock tower and IIII instead of IV. Always struck me as odd to make such an elementary mistake.


Historically, the Romans used both IIII and IV for 4. The subtraction notation was not standardised until much later. There are plenty of instances of IIII on things like coins from the 17th and 18th centuries (though not that much for dates, for which a shorter notation was preferable), and examples dating back to Ancient Rome.

So, it was at worst old-fashioned but never erroneous.


One is often better served by considering that, when faced with the unexpected, oneself might be the mistaken entity.


In my field this proverb usually comes under the form of "it's probably not a kernel bug, but a bug in your code."


I distinctly remember a (the?) clock in the opera "La Scala" in Milan had the roman "IIII" on it.


TLDR; it’s a watchmakers four and IIII is for horizontal symmetry against the heavy VIII for eight.


It is not. It is an ancient notation that became fashionable again when clocks were being developed. Watchmakers just followed the sensibilities of their times, and everything sophisticated had to look Roman.


> became fashionable again when clocks were being developed

Why do you think it become fashionable again when clocks were being developed?


IIX for a watchmakers 8 would be even more symmetrical.




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