Horoloscopy and Uncertainty

Let's begin with that first word in the title of this post: horoloscopy. As far as I know, I made it up. It is a riff on the term "dactyloscopy," which is not a term I made up. Dactyloscopy is the study of fingerprints in order to establish identity. Most of us are familiar with this practice from crime movies and stories. A detective "lifts a print" off a crime scene, sends it to "the lab" and a "match" in some database of known fingerprints reveals the identity of a person of interest.

An AI generated image of a watch with a fingerprint on the dial.

So what do I mean by this made up term "horoloscopy"? Well, since I made it up, I guess I get to define it. No, it's not an unpleasant procedure recommended for your watch when it hits 50 years of age (sorry, couldn't resist). Instead, I'd define horoloscopy as the study of minute wrist watch characteristics in order to establish the identity of a wristwatch. Now, I want to be clear here, I'm not talking about a process used to establish that a wristwatch is genuine. We already have a term for that: authentication. I'm talking about a process used in an attempt to establish that one watch is exactly the same as another watch (or perhaps one watch component is exactly the same as another watch component).

To me, the unsurpassed master of horoloscopy is a man known as Jose Pereztroika (you can find him on Instagram using the handle @perezcope). I'm a big fan of his blog, Perezcope. There, Jose has surfaced some really important facts about the history of watch brands. He also presents compelling evidence tracing watches and / or watch parts through auction history. Jose's assessment of particular auction listings is always fascinating and, honestly, extremely important.

However, we really should start from a position of skepticism when it comes to auction lots and blog posts (including this one!). As I've read Jose's pictures and naratives presenting points of similarities across photos of watch dials, movements or other components, I've always had a bit of lingering doubt about methodology. Do we really know that matching blemishes shared across watch parts truly establishes the uniqueness / identity of those parts? How do we know this?

Here, I'll make the case that the reliability of horoloscopy is largely unknown when it comes to establishing the identity (uniqueness) of a particular watch part or an entire watch. Now, I could be wrong. It could be the case that 8 visually similar flaws across watches means that there is 1 in one gazoogalmillion (another made up term) chance the two are not the same watch. But, I think we need to acknowledge that there probably is a fair bit of uncertainty when it comes to horoloscopy as a method.

I was pretty shocked to learn that fingerprint matching, which is quite analogous to horoloscopy, has its doubters. According to an article in the Smithsonian magazine, as recently as 1991 a judge in the United States stopped accepting fingerprints as evidence of identity. The same article notes that at least 23 individuals have been wrongly connected to crime scene fingerprints. It does seem, though, that arches and whorls have been reliable elements that establish identity, although we don't have a great sense for exactly how rare fingerprinting errors might be according to this 2011 article.

So, why do I think horoloscopy is likely less reliable than dactyloscopy?

An AI generated image of "two Rolexes that are the same model." There are clear similarities but there are also differences.

Let's begin with the observation that humans and their fingerprints are generated through a fairly foible-prone biological process of genetics and other things I'm not qualified to discuss. We know this gives rise to an incredible diversity of all sorts, and as a result fingerprint features probably are quite unique. Watches, on the other hand, are manufactured. In addition, that process of manufacturing is intentionally designed to produce parts that are as similar to one another as possible. This also means that flaws are likely replicated across parts. A weird mark here or a scratch there may actually just repeat across dials, for example, because that's what is happening with the machinery. There is a fantastic article on A Collected Man about famous mistakes that have been replicated across examples of certain watch designs. So we already have evidence that foibles are not always unique to a particular watch.

Second, even if blemishes and marks on watch parts are valid in establishing identity, how many blemish matches do we need in order to have confidence about an identification? Law enforcement won't accept a small number of similar points across fingerprint examples as sufficient evidence of a match. At one point in England and Wales, 16 matching features were required before a set of fingerprints would be used in a court of law. I'm just not sure we have any sense of the analogous requirement when it comes to horoloscopy. If we're going to use blemishes to match watch parts, it would be helpful to have a thoroughly explained basis for the minimum number of similarities that would establish identity.

Last, I would like to see more exploration into whether photography, as the medium used to establish a match in watch blemishes, has unique characteristics which might limit the reliability of horoloscopy. Do we need to make sure that pictures of a watch are taken with similar settings, lenses, lighting, or perhaps even the same camera in order to have confidence in a visual analysis? It is certainly true that fingerprints are not always fixed in the same medium. One print might be ink, the second might be dust on an adhesive. But with fingerprints, we're doing a fairly straightforward assessment of two dimensional patterns. Watches have all kinds of hue and three dimensional features that may seem more similar through the lense of a camera than they really are.

I think horoloscopy is a fascinating practice that has great potential to shed light on the path followed by particular timepieces. I don't have concrete suggestions for how we might make this practice more reliable or precise. Until the practice of horoloscopy is more refined, it is probably best to treat its results with some caution.

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My book on the history of Rolex marketing is now available on Amazon! It debuted as the #1 New Release in its category. You can find it here.

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