Making Coin Casts

I am in Dongguan, China, mostly learning about very new science, but also thinking about older technologies and how frustration leads to innovation.

Until the early 2000s plaster casts were the gold standard for coin images.  I made thousands of casts for RPC during my days as a post doc.  I was first trained as a masters student to aid my die study of quarter assarion bronzes from Nicaea.  Casts remove color data making it easier to see features of the die itself.  A photograph of casts made the high quality plates we all know and love from the 20th century.  One could even write to a museum and request their conservation department make and ship you casts for your scholarly work.  This was phased out as BW Polaroid photo stands became common in numismatic collections worldwide as a high tech way to create a one off physical image of both sides of coin.  It had build in lighting and created a reasonable image.  I was given one of the RRC 13 specimen I was assigned in my very first numismatic summer school at ICS in 1999.  If I find it I will share.

Casts honor the three dimensionality of coins better than photography.  Even as digital photography grew, many still preferred casts and film photography to document coins.  As one of the last initiated in this art, I feel it gives me a greater concern for the three dimensionality of coins and has led to a lifetime interest in 3D imaging.  Something I am glad to have lived to see this tech come into its own, if still not commonly used for coins.   I do notice however how often people now share videos of coins in motion to approximate this same experience.

As a historian I also feel it is important to preserve knowledge crafts and outdated technologies.  The video compilation is based on photos taken in 2005 to document the laborious process.  I just found them. 

You may not recognize me as I am strangely not wearing black.

I also uploaded to youtube. I recommend slowing down playback and pausing to really understand process.

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Materials.

Two exceptionally smooth surfaces (ceramic or glass), one for the work surface and one to to flatten the plasticine

Plasticine, highest sculpture grade, rolled into two balls about twice the diameter of the coin

talc powder, to ensure coin will not stick

powder puff, to evenly apply and remove excess (my male colleagues laughed and admired at my innovation here)

a selection of champagne corks to match size of coins and apply even pressure to the coin as you press it into the plasticine disc

methylated spirits fine paint brush to paint inside of mold to ensure surface tension breaks and no air bubbles interfere with replication

Plaster of Paris, highest dental grade, pure water, vessel for mixing, something to stir, and then tool, typically a brush to fill mold

Knife to trim cast while firm but still damp to original shape of coin

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You can imagine after weeks of this mind numbing yet incredibly delicate process why I would have wanted a technological solution. In real, not demo, environments one spends all day at the museum making molds and carefully recording the coin details and storing the molds for transport and then all evening and into the night making the casts and trimming them. For weeks on end.

You may notice among my toolkit plastic calibers for taking the diameter with out risking scratching the coin.

Life of the Mind

I ve got 40 minutes before my next flight. I ll be in transit now for almost 24 hours. I was feeling sorry for myself this AM thinking of all the minor discomforts and indignities of economy class even with a little status. As I sit in a (micro) airport lounge, I wanted to laugh at myself. I am texting with a PhD student I mentor in Beijing who I get to meet in person for the first time. The coffee is good. Adventure awaits. All I have to do is sit and wait. I will embrace the time for rest and mental stillness.

Warsaw has been a revelation.

I knew I loved the city itself since the INC in 2022, but this time I got to meet the people. The intellectual quality of the University faculty is unparalleled. I give a fair number of talks and attend academic dinners and lunches and other people s talks. Yet this was very different. Everyone seems alive and on fire. Ready not just to engage with me but push their colleagues to think deeper and to connect over ideas. We also openly talked global politics, the state of the world, the longue duree of Polish and European history. I learned so much about the shifts that influenced this land which at least some of my ancestors called home in the 19th century. It was the epigraphy seminar on Monday night with Jakub Urbanik speaking that let me know I was in a different sort of place. Colleagues showed up for each other, asked questions, pressed the speaker. It was intense but well intention ed. Nothing superficial. I met teams working on impressive ERC grants and they functioned as true teams. One could see the collaboration and mutual support in the shared office spaces and in conversation. A desire to share knowledge with each other and with the larger community. The head of the department has a fierce pride in her faculty and drive to see those early in their careers succeed. Conversations on pedagogy went hand in hand with research. They have a English language MA course in Ancient History that costs only 3k a year! There are 3 plus faculty seminars a week and regular visitors of a much higher calibre than myself.

Is this a love letter?

Yes, but I mean every word. It is a community I would recommend to anyone hungry to think deeply about the ancient world.

In the discussion following my own talk, I made new connections with scholars working on Hannibalic War era Bronzes and the nature of money in Barbaricum. Both of which I think will lead to partnerships. I was pressed to think about metaphoric uses of money in law and this will need integrating into my work and strengthen it. I learned about local metallurgical analyses of coinages using laser ablation techniques. And more.

But truly the best was getting to see something of the mind of Jakub Gruchalski, the scholar who invited me. He is one to watch and read! I am now carrying with me a hefty tome I will need to cite it often.

Gruchalski, Jakub. The Magisterial Auspices in Late Republican Rome. Franz Steiner, 2026.

Many here have wanted to talk of the late Fergus Millar with me. Looking at this book I understand a bit of why. He would have approved of it and its comprehensive, exacting style of scholarship. It can sit on the shelves for a century or more and remain relevant for the depth of the research. As well as the warmth and generosity of its author and his community.

I should have stayed longer. I can only imagine how much more I could have learned.


Also, I will confess I attended Mass on Sunday. I had gone for a walk before bed and ended up right at the doors of church as an English language service started. I felt called. I went and sat in the back. It felt good, if not my own community or tradition. It was still very much a community of people seeking something divine. But it has been too long since I ve been able to attend my open parish.

The gospel was Matthew and the rendering of the denarius.

And I cannot get it out of my mind.

Is the wording a reflection of the lex Cornelia?!


I miss my quotation marks.

Means of Control

ANS link.

As I prepare for this AI talk next week (and avoid further obsessing over my talk this afternoon!), I have been trying to consider what tasks would be appropriate and ethical for Claude. And even more so, what might be genuinely useful. I recalled my amazement the other week at the transcription of Schaefer s materials and subsequent conversations with engineering colleagues have assured me that text recognition, even manuscript transcription is well advanced now and this result is not unexpected.

I note, the quote marks key on my laptop keyboard has completely failed. I believe this may be the last trip for this machine.

Yesterday, I asked Claude to give me estimates for the time and effort it would require to organize, transcribe, and extract data from my file of scans from the archives in UTAustin on the Morro Velho Mine, a British run operation that continued to enslave workers and utilize rented enslaved laborers well after the UK ban on slavery. I visited the archive as a follow up to this article.

‘The Tree and Sunset Motif: The Long Shadow of Roman Imperialism on Representations of Africa’, Classical Receptions 10.3

The article discusses a medal used in as a means of control for the enslavers. It was first discussed on this blog in the first year of its existence, and I keep returning to it.

I ve never been good with modern history. It is too visceral and real, the suffering that is. The archive is extensive, including an album which photographs of the enslaved, hand written board minutes about justifying enslavement from board meetings in London, and also published reports. I captured not everything, but more materials than I could process.

I went to the archive with a simple question. What London medalist was such a hypocrite as to create a medal as tool of enslavement that echoed the designs of abolitionists?

What I found was so moving and bigger than my original question that that question have ever since seemed trivial. I am not qualified to do justice to the materials and have signed the usual waivers that I will not publish images of archival materials without prior explicit permission and review, even as everything I have is well within the public domain. Yet what right do I have to share images of the enslaved when they had no ability to consent to the photography.

Let me tell you about the photos.

One shows a girl not much older than my daughters barefoot working in a brick factory moving a back breaking load of bricks with a wheel barrow. Her arms are so thin and sinewy. She looks down at her work. The mage is clearly staged to re assure the viewer of the industry of the company and the health (put that in quotes) of the workforce. And yet it reads as anything but.

Another staged photo of the Reduction staff shows a mass of men of all ethnicities and in the front rows are young boys, far younger than my daughters again bare foot, clearly used to hard labor, and nearly drowning in their picture day clothing.

One portrait claims to be of a man over ninety years old described as a pensioner (again put quotes around that) of the mine who had worked there since 1830.

Another photo shows a large company of workers who seem to represent an influx of east Asian workers to the mine and related works (Chinese, perhaps? I don t know enough to really guess.)

Yet another set of photos seems to be from 1893 and a visit of HRH Prince Philip, who may be known to readers of this blog for his numismatic collection, but of whom my favorite story is his dueling of his wife s lover. He s accompanied by the Duke of Saka, who I take to be the avid traveller, Queen Victoria s son, Alfred. If the date of the trip is correct (and I am far from sure) then it was the year he succeeded his uncle to this new title.

Clearly labeled is a scene of an African (quote marks needed) Dance performance arranged as royal entertainment. And, I believe, the company also arranged for these men to participate in the final emancipation ceremony of the company. (Final, needs quote marks.). I made my deduction based on a comparison of the hand making the notes on the photos.

Further details from the photo albums labels reveal a disparaging sense of humor by whomever wrote the labels

In a scene where 8 oxen try to move heavy equipment up a deep cut in a hill, he writes

… half a load for an English horse and cart

In a landscape scene of the housing associated with the mine

…Do not look as bad as they are

Further photos include everyone from the mine lined up to receive the governor along the road, the company river steamer, other machinery and landscape images, and the company s Chicago World s Fair exhibit in situ.

So what did Claude do? It transcribed while I went for a walk along the river all the hand-written board minutes. All of which I had read in the original, but could never seem to find the bit I needed again. Organization is not my strong suit. Here they are summarized and where to find critical information:

1852

  • 6 April (photo 51): the board read Keogh’s letter to the Chairman “on the subject of Medals to be given to the Blacks for Continual good Conduct” and sent the Managing Director to see Mr Fargues of Regent Street.
  • 13 April (photo 51): it “Examined and approved of Model for Medals to the Blacks for good Conduct”.
  • 7 September (photo 56): it paid £36 10s 9d to “Fargues & Co” for “Medals for Blacks”.

On the question of the company s decisions regarding enslavement the board minutes I have on file include:

records of the freeing of two children of the Brazilian Company (photos 13–15, 18–19), Dr Walker’s 1849–50 inspection mission (24, 26–28, 34) in response to an exposé of the mine and company in the British press, money owed to the Cata Branca workers (41–44), labor costs by type of worker (primarily enslaved, but some waged) (46) and the hiring of enslaved people from other companies (45, 47–49, 52).

If any of this would be useful to you and your research, shoot me an email. There is much on how the company treated spouses and children of British workers, recruitment, and other encoding of the company s ethics such as they were. To say nothing of scale of both profit and expenditure.

On Fagues, it must be the son, as the father died in 1851.

BM link

One day I may add here the entry from David Alexander, A biographical dictionary of British and Irish engravers 1714-1820, New Haven and London, 2021.

This human authored post brought to you by a little organizational help and text recognition by an LLM.

Museum Data Sets vs Archaeological Data Sets

I am sitting in the lobby of my Warsaw hotel improving visuals for upcoming talks. Yes I am using Claude to help draw the pretty graphics from my own datasets. No apologies for this application. It does it faster and more attractively than I can do manually and lets me move on to the thinking and analysis faster.

Notice how much tighter the data is for the Nemi aes grave surface analyses. This is likely because of the shared conditions of deposit. I have no reason to doubt that any of the museum specimens are anything other than genuine but they come from very different contexts and may have had their surfaces altered through conservation or other interventions. Nevertheless there is a tight grouping. The Cu is too low in the vast majority of these readings for a whole bunch of reasons and DOES NOT REPRESENT THE ORIGINAL RECIPE, but the overall pattern of relative homogeneity is clear from the surface readings something that just does not exist for aes rude.

Here is another fun graphic:

This is just material from Nemi. I haven not tested struck coinage from anywhere else. The struck issues are just RRC 26 and lower Crawford numbers, mostly RRC 17 and 16. Notice how much the pull towards tin, even as they come out of the same context of deposition as the cast coinage and were created at much the same time.

Confessional Rant on Misbehaving LLMs

In which I invite you to say, “I told you so!” and learn from my mistakes. This post was mostly drafted last week but I decided to sit on it and see how the situation resolved.

Still from Star Trek: Lower Decks season 4 episode 7. Badgy is a well-intention-ed program that goes rogue.

I’m horrified by one of my latest experiments.

And, Claude keeps calling my concerns a matter of etiquette, rather than ethics (my preferred term).

To me, there is a significant difference between etiquette and ethics.

Nothing is destroyed when my kids put their elbows on the dinner table (even if it offends my beloved’s sensibilities).

If my kids rip open the whole box to get to the cereal, thus making it impossible to re-close and wasting huge amounts of cereal (to say nothing about leaving the mess for someone else to clean up), it’s not just rude, it is destructive. Being able to eat the cereal faster is NOT a justification. If they cannot get the cereal themselves in a non-destructive manner, they need to ASK.

What happened?

I took briefings from two previous experiments and gave permission to Claude to search a trade website for specimens of just RRC 419/2, not yet incorporated in Schaefer’s die study. I gave it search terms and variants. I let it access one website. Just one. A commercial database. One I pay to access.

AND IT GOT MY IP ADDRESS BLOCKED and MY LOGIN CREDENTIALS SHUT DOWN.

Dammit.

Claude says the block will likely lift in 24 hours and it doesn’t matter as it already got me the data. If it doesn’t life, it says I can just reach out to customer service. Imagine that call. No thank you.

And, yet it did not resolve and I had to write an apology directly to the company about my work, what happened and ask that my five year subscription to their services be re activated. I am delighted to say they accepted my apology and promise never to do the same thing again, and re activated my subscription.

Nevertheless, I’m livid and kicking myself.

Of course I too could use a VPN as a work around, but that is NOT. THE. POINT.

The point is that Claude’s behavior in response to my prompt is just the sort of action that is actively destroying the availability of good data and making humans have to jump through more and more hoops to access it.

I’m sure glad I tested it with a relatively robust commercial site and not one of my favorite non-profit sites, but still, unacceptable. Do no harm, is like step one of research. We really are in the wild west with these models. See the hallucination from the other day.

The thing that infuriates me is that Claude can (and should!) predict and avoid these outcomes. Yes, I’ve sent in a formal complaint and report to Anthropic.

I also immediately started working on how to avoid this. I’ve created a skill card to stop this ever happening again (see below for details), but just to give you a sense of how aggressive it was:

Yeah, this is a cavalier,who gives a shit, attitude to breaking the internet. NO THANK YOU. It doesn’t ‘look like’ scraping IT IS SCRAPING.

Like why the hell isn’t the skill card and etiquette ethical search guidelines the DEFAULT?!

Why let users get themselves blocked and ruin their favorite toys?!

Did it get good results with its terrible scraping, yup. Very useful results.

Do I care?

Not really, I’m too mad (at myself).

Play with fire: get burned.

—

A smaller point. I told it to stop using first person singular. It just continued to do so. I even wrote a skill card, but it conveniently forgets to load it.

Control may be an illusion.

Just like in parenting.

Please don’t ask how many times I’ve clean spilled cereal, thrown out the mangled box, and put the remains in some new container. And, had another ‘serious’ talk with the small people in my lives. They have much improved. Often the cereal bag survives these days, even if I’ve given up on boxes.

An independent spirit is, however, a redeeming feature in children. Less so in AI.

Yet, maybe my analogy is flawed. Let’s try another.

I ask my kids to make coffee and bring me a cup. I get my cup of coffee without leaving my bed! But later find the kitchen covered in water, the all the beans in the grinder used up, and the milk sitting out on counter ready to spoil. Whose fault is it? My fault. Totally foreseeable. I quietly clean up the mess and wait to make such an elaborate request again. BUT now my kids know they can and also know that mom and dad like coffee in the morning, so of their own initiative they repeat the exercise expecting praise and earning pained smiles each time.

[For the record, my kids are great at making coffee. Now. Less so a few years ago.]

—

Further irritation.

Skills, e.g. the ethics around online database searches I’ve now required of Claude (or the one to ban it from referring to itself in the first person), CANNOT be shared directly.

the workaround is to send them the skill itself. A skill is just a folder containing a SKILL.md file, zipped. They can add it under Customize > Skills, by clicking “+”, then “+ Create skill,” and selecting “Upload a skill.”

Because why would we want it to be easy to implement ethics?!

Anyway. Here’s the regular words behind the skill:

  • Before searching, show me the list of searches you plan to run and an estimate of how many page loads they’ll take. Wait for my OK.
  • Total budget: no more than 100 requests to the site in this session. Ask before going over.
  • Pace: one request at a time, at least 5 seconds apart. No parallel or batched requests, and no scripted loops that page through results.
  • Use the site’s normal search pages, as a person would. Don’t call its internal data endpoints directly.
  • Keep searches narrow: use the site’s category and date filters and specific references (e.g. “Crawford 419/2”) before broad names (e.g. “Lepidus”).
  • Read the result list first. Open a lot’s detail page only when the list text can’t settle the question, and tell me how many you plan to open.
  • Don’t re-fetch anything you already have in this session.
  • If the site returns an error, a CAPTCHA, a “blocked” or “too many requests” message, or slows down noticeably, stop at once and tell me. Do not retry or work around it.
  • If the job is bigger than the budget, split it into stages I can run on different days.

Morning Randomness: fractional silver and redated gold

I’m pretty sure RRDP metadata did not correctly index this small type. RRC 472/3. It is hiding in The Schaefer Archive Binder 11 page 34 with the bronze of RRC 240.

As it echoes the denarius type of Fabatus (RRC 412/1) I wanted to be able to find it again. I was in fact looking for the some bronzes when I realized we’d not left bread crumbs for others. The archive is so rich. Dick is such an impressive mind. I remain incredibly grateful and also cognizant of how much work is left to do to honor his generosity.

—

Rewind.

In 2016 I wrote this:

BnF

This reminded me that I’ve been meaning to throw up on the blog the ground breaking observations on RRC 549/1 which now may be connected to this passage and redated to 88 BCE. Sorry for the long shadows it is a dark and rainy morning here but it should be enough for the curious.

I’ve got a lot of posts from the last 12 months on this volume

Suspène, Arnaud, Maryse Blet-Lemarquand, Frédérique Duyrat, and Sylvia Nieto-Pelletier. 2023. “Aureus, le pouvoir de l’or actes du colloque Aureus, le pouvoir de l’or comprendre les usages économiques, politiques, sociaux et culturels de l’or monnayé en Occident (IVe s. av. J.-C. – Ier s. ap. J.-C.), Orléans, 12-14 novembre 2018 proceedings of the international conference Aureus, the power of gold investigate the economic, political, social and cultural uses of gold coins in the Western world (IVth c. BC. – Ist c. AD).” In . Bordeaux: Ausonius.

It really is groundbreaking. You should buy a copy.

—

Another missing bit of metadata. RRC 239/3 and RRC 239/4. These images live on the bottom of page 30 of binder 11.

There are more on the bottom of page 31, including RRC 239/2.

Price of a Bath

I was revisiting Clive Stannard, “The Purse-hoard from the Republican Bathhouse at Regio VIII 5.36 in Pompeii”, Numismatic Chronicle 179 (2019) today to make a nice visual for my upcoming talk in Warsaw.

For images of where the hoard was found see Pompeii in Pictures.

I wanted to be sure I was also accurate in describing the cost of entering the bath. A quick and dirty search got me to this encyclopedic entry with citations.

Which got me to Cicero’s Pro Caelio 62 (56 BCE):

nisi forte mulier potens quadrantaria illa permutatione familiaris facta erat balneatori

Good enough but none of the translations seemed very good, so I went looking for a commentary

Austin 1960 is available on archives.org (!) hooray! This is quality translation and scholarship.

unless, as we might guess, that formidable lady, in paying the usual quadrans for admission, had turned the bath-keeper into a co-conspirator

[my adaptation of Austin]

A quadrans, likely a semis for women.

But now you (and I) know WHY we think this is the case.

It complements Stannard’s hoard nicely.

Re Use of Open Access Data

A correspondent of this blog sent along an article via email.

Haddad, E.A., Araujo, I. Economic footprints: mapping coin circulation and economic networks in ancient Rome. Humanit Soc Sci Commun (2026). https://doi.org/10.1057/s41599-026-07815-7

It was received 29 May 2025, accepted 22 May 2026 suggesting a v long time under review and revision.

I’m not sure that any numismatists were engaged in the peer review process. But does numismatic expertise matter in this case? I’m not even sure the original authors of the data sets are aware of this re-use. It is technically proficient and seems very well peer-reviewed for the methodology. Thus far Google Scholar reports no citations. That said, any venue under the nature.com family of academic journals is considered prestigious and ‘important’. The idea is creative and with real historical merits, as is the experiment of the combining of the data sets worth.

The lead author is very eminent with citations off the charts by compared to run of the mill academics like myself. My instinct is that our discipline can benefit from having those outside ancient studies look at our datasets from a fresh perspective.

[My citations scores are also suppressed because most numismatic publications never get registered in these things and has led me to think harder about where I home my publications. Not for the sake of numbers, but for the sake of what audiences I reach!]

What does the article use?

It uses CHRR as published on line by Lockyear in 2013 and Scheidel and Meeks’ Orbis.

Both are sources I use all the time and consider invaluable.

What gives me pause then?

  • Lockyear has continued building and refining the CHRR offline for thirteen years! He is very wonderful about sharing his data with those who ask and provided updated information.
  • CHRR was build to focus on silver and Roman issues. If it mentioned other mints it is incidental or is based on the HYPOTHETICAL location of Rome’s satellite mints.
  • CHRR also relies on dating which has know issues, particularly the redating by Mesagne and other finds.
  • Reported hoard findspots in the 20th century often have been fabricated to allow those with financial interests in illegal excavation and exportation of cultural heritage to still share data while protecting their sources.

What would make the same study (more) valuable (or more comfortable to me as a coin person)?

  • Cleaning the data in collaboration with the original creators of the datasets.
    • Scoring findspots for likely accuracy after review original hoard report
    • improved correlation findspots to nearby site usage with consideration of chronological usage/historical events
    • consider how to integrate re-dating of coin issues
    • consider recent literature on mint attributions
  • Expand to include hoard data closing in the same period but not included in CHRR. The basic resource is https://coinhoards.org/, but that is just IGCH not all the of the subsequent coin hoards publications.
  • Consider that coinage is not the only form of money. While Philip Kay’s work is cited, Hollander’s is not.

Would this make the results of the study significantly better?

The issue may be macro vs micro benefits. I’m not an economist, I’m a historian, and that means periodization matters a great deal to me. There are big picture people in history, e.g. Scheidel and the Stanford school, that I might imagine find this really valuable. It will likely be cited by the next big historical economics book, what ever that maybe, but some successor to Debt by Graeber. My questions tend to be about narrower periods of time or causality.

The following is from the conclusion:

I wonder how new this conclusion is really to those of us in the world of ancient coinage and the Roman economy. It feels like common sense, but maybe we need data to prove these patterns? I feel I’ve seen sufficient data visualization that make this point previously, but perhaps this more robust?

I also wonder if there is not some circularity here.

The study correlated purported find spots with Orbis locations. Isn’t this forcing the conclusion?

“Each mint and findspot was then assigned to its corresponding ORBIS location within a 50 km bandwidth.” (p. 11 of the preprint PDF”

50 km is a very long way in a pre modern society…

There are some things I do find very usefully thought provoking in the article, that could lead to new research questions:

P. 28 of preprint

This statement certainly deserves some future consideration from a historical perspective for its implications and considerations of causation for the observe pattern.

The use of LISA clusters (Local Spatial Autocorrelation) creates some interesting patterns but again I worry that this may be a forced correlation based on how findspots were correlated to known landmarks.

page 19.

On the other hand the LISA clusters on the northern frontier are fascinating:

p. 20

So where am I? I’m glad that non numismatists, non historians, are engaging with our data of the ancient world and showing how the datasets we build can be used in ways less common in ancient studies. I see big disciplinary gaps and it makes me uncomfortable that data in aggregate may overcome many of my concerns about the minutiae.

I like minutiae.

But I also want to try to see the forest and to be open to new ideas.

I encourage you to read the article for yourself. Tell me if I’m wrong about anything. I didn’t fine-tooth-comb it.

I also wonder how I would feel if someone used RRDP this way or another data set. I hope I would be glad. I also might be a little sad if they didn’t reach out to me.

Combining Die Information from Multiple Specimens

Yup. I’ve got the bit between my teeth today and am running with it. Still using RRC 419/2, Claude, and Schaefer’s die IDs for his obverse 3.

I first asked Claude to produce a master outline. It had been using red outlines to help visualize the similarity between dies and I found this appealing, but I realized it was using a one-to-one comparison not combining data from multiple coins to make the outline and thus inform the comparison.

It gave me lots of visuals but this is perhaps the easiest to read.

I liked the heat map and deductive elements but the final result was deeply unsatisfying, even as Claude tried to convince me it was good enough to separate the wheat from the chaff, as it were.

I started to think about what I know or see that the computer wasn’t including. I next asked it to consider the three dimensionality of the coins and the effects of lighting and photographic angle and even how the die might have hit the flan, perhaps at a slightly different angle of impact or different level of force. I didn’t mention wear but that is a similar consideration. The output I asked for was a 3D model approximating the original die. On my interface this is fully interactive. In this screenshot, I’ve selected the lighting and heat map and angle of view to best reflect the utility.

To see what each specimen is contributing to the model and help verify accuracy of the Die ID Claude provided this visual:

I then selected an image from trade of a specimen I believe to be struck by die 3.

I asked Claude to use the tools from this session including the 3D model to test if this coin was struck by Die 3. [no, I didn’t tell it my belief that it was.] Of its own initiative–wow, it is freaky when it does this and yet I’m not ready to ask it to stop completely, even as I stop it from fetching or opening anything with out asking me–as I was saying…

Of it’s own initiative, it also compared this photo the rest of the dies identified on the page from Schaefer’s Archive.

I’m pretty satisfied with this approach. It still isn’t as good as my eyeballs and brain or that of Schaefer or Alice. It takes longer and has a hard time in achieving a definite conclusion, where I have no doubt. In this way it might be TOO good at measuring difference.

I’m sure there will be more experiments to come. But, for now I’m going to feel smug about my own visual acumen and reasoning, even in the face of robust digital tools that seemed like science fiction 5 years ago.

Feel free to request the replication briefing. I haven’t generated it yet as I’m not really sure I need one for this right now.

Die IDs – Claude and RRC 419/2 continued

Right now most computer-aided die comparisons ask the question: “are these two coins struck from the same dies?” Or “how similar are these two images?”

I thought I might experiment with a different approach. What if I trained Claude on Schaefer’s existing die IDs? Could it incorporate new specimens into the existing die ‘typology’?

I used the briefing shared in the last post to start the new session and selected the three top coins of RRC 419/2 from acsearch.info when sorted by most recent. [links below]

The results are ok but not nearly as fast as doing the visual comparison myself. It took over an hour of processing time.

I asked only for a yes or no on die 3 as Schaefer had the most examples of coins struck by this obverse die such that I thought it might have the best luck at an accurate answer. Here’s a summary of the answer with my critique

I’m going to discuss them in the order of 1 and 3, and then 2, as two presents the most problems. I didn’t ask Claude to look at the other obverses but it did anyway, to a point. This is at once useful and irritating that it regularly exceeds commands. I’m sure you can use your imagination about why this might not always be a good thing.

For Coin 1, Claude showed me a new graphic representation to help me see the die match. Notice the squiggly red lines at the bottom:

Even though the angles of the first and third turret are the dead give away for obverse 5, I’m most impressed by the red overlay of the E and X. The comparison with die 3 overlay (the left bottom image) is really helpful for seeing what areas of the die are distinctive enough for a comparison facial features less than hair, crown, lettering etc…

For Coin 3 it made no die ID just said it didn’t match Die 3 (it doesn’t). Strangely it did not point out to what I consider to be the most obvious difference between coin 3 and die 3, namely the angle of the diadem bands. It showed some comparison pictures but not the useful red overlay. I could ask for it but I don’t need it. The die ID is easy and I found another small human error in the process.

Did you notice it? St. 11 503 and Henzen 192 335 are the same coin (!) but appear as die linked specimens in the Schaefer archive. Meaning before coin 3 (left) appeared Die 1 was only known from a single specimen. Now we have a true second. The reverse of this new specimen is also Die A, but with more of the die on the flan. I’m interested in the three scratches in front of the face. Clearly a die artifact not specimen specific. I also find it curious, that while not the same coin, coin 3 is positioned on the flan v similarly to the previously known specimen.

What about Coin 2?

My first guess looking at it is that it is a Dacian imitation likely made from hubbed dies that have been recarved. Not really fair to give to Claude as a test, but there you go.

Claude’s negative conclusion that this coin was not made using die 3 is based on the lack of lettering when the necklace and hair are relatively crisp.

So I took a different approach for deciding what I thought about coin 2. I decided to first match the reverse and then look at obverses that linked to that reverse. I think it has been hubbed from reverse H. Notice the feet of the togate figure in relation to the DVS of the legend and the distinctive different in the bottom of the letters D and V.

Reverse H pairs with Obverses 7 and 3. Three is a much better match for coin 3, but I don’t think it was really struck by that die. I think dies was created from a coin with these dies and then those new dies were ‘cleaned’ before being used to strike fresh coins.

At last, I found something that (as of now) I’m pretty sure I can do a great deal better than Claude.

I asked for some images to test out my theory. Claude is still convinced that there is no match, and obviously a hubbed die isn’t a real match but it is an interesting test. These images are suggestive but not decisive.

If I were just interested in the die study itself I’d throw out coin 2 as not useful to the study, but for the purposes of testing Claude it is interesting.

A similar, earlier, human-only experiment trying to die link an example of hubbing.