Roman Numerals in watchmaking
And how modern brands adapt the Roman numeric system to their wristwatches.
Did you ever wonder where Roman numerals origin from and how are they used on a wristwatch's dial? Back in time, during the Roman Empire, Roman numerals were adopted on meridians, while they decorate today a classic watch's most beloved dials, and are a primary choice on classic-looking tourbillon or minute repeater watches. Conversely, sports watches preferably showcase Arabic numerals instead or no numerals at all, as that's the case with a professional divers' watch, where broad and highly-glowing applied indexes are used. The Roman numerals originally appeared as a mean to perform calculations in a simple, easy-to-manage way across different social classes, in an age where higher education was restricted to a selected group of people.
Where does the Roman numeric system originate?
The Roman numeric system origins from the engraving of notches on a piece of material: figure "I" stands for one, figure "II" for two and so on, up to figure "V" that stands for number five and symbolizes an open hand (i.e., five fingers), while figure "X" stands for ten that signifies two open hands. Intriguing, isn't it?
The origin of Roman numerals has a substantial symbolic value. The number five and its multiples all feature dedicated symbols, and when numbers smaller than ten occur, the subtractive notation is adopted. Oddly, the number four can be found in two alternative forms, either as IIII, according to the additive notation, or with the figure "IV," according to the subtractive notation; this is a specific case that has a historical explanation.
If we take a look at a classic watch's dial, like a Santos de Cartier, for example, we reckon the brand extensively uses Roman numerals as a design factor; the brand's designers opted for the additive notation, vice versa a few brands have gone for the subtractive notation. During the Roman age, the additive notation regarding number four was mean to avoid offending Jupiter, whose initials, in Latin, are I and V (IVPPITER). Another possible explanation is that Roman numerals that use the additive notation were, again, easier to use by poorly educated people, who were less or not familiar at all with maths.
It wasn't until the late Middle Ages that the number IV progressively replaced number IIII, and that's the reason why the majority of striking clocks across Europe, like the Big Ben in London or the Kremlin Clock in Moscow, show the number IV on their big dials. However, there are exceptions to the rule mentioned above: the Peace Tower, in Ottawa, (Photo by John Talbot from Ottawa, Canada - Peace Tower Clock, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=3788284) shows the number IIII instead.
How the Roman numeric system applies to wristwatches.
The Roman numeric system, according to the additive notation, is the primary option to most watch brands since it guarantees better aesthetic balance at first sight.
If we carefully observe a Drive de Cartier's dial from up-close, it looks like the dial can be formally split into three thirds: the first third includes Roman numerals from I to IIII, the second sector from V to VIII, and, finally, the last one covers from IX to XII.
In my opinion, this rule is successful when numerals are big and bold, as on a Cartier watch, but not all brands abide by this rule.
Moser watches, for example, has chosen figure IV instead, on its Heritage Perpetual, Moon and Tourbillon complicated watches, and their overall balance is excellent.
Here is a brilliant example of a watch showcasing Roman numerals.
If I had to mention an excellent example of a timepiece featuring Roman numerals, I would rate the Rolex Day-Date 40 at first place. With this exclusive collection, Rolex introduced a rather modern and original take on Roman numerals' design.
The brand adopted the additive notation to create a striking and bold dial featuring multi-faceted indexes, mated to various dials, including their signature Wimbledon green dial, thus making ref. 228238 pictured above, and its siblings, some of the most charming gold watches on the market.
(Photo credit: Horbiter®'s proprietary photo-shooting, courtesy of ROLEX)
Gaetano C @Horbiter®