Recapping ECFN / Nomisma in Sofia and Hackathon Athens

I am finally back in the office as of yesterday following two weeks in Europe for two related conferences: the 10th joint meeting of Nomisma.org and the European Coin Find Network and Hackathon Athens, hosted by Thomas Faucher at the French School of Athens. The former meeting is increasingly a formal conference while the latter included presentations of the current state of several projects which jumped off two days of workshops and roundtable discussions. After the conclusion of the Hackathon, I helped install Numishare on a cloud server for CEAlex to publish coins from archaeological excavations in Alexandria, Egypt.

My presentation at the ECFN/Nomisma conference, "FAIR Findspots: Making Data Reusable," is about the current Nomisma.org data model for representing findspots and linking findspots to existing gazetteer URIs, such as Geonames or Wikidata. I discussed interoperability through using HTTP protocols (content negotiation) which enable external database systems to reuse hoard/findspot data for cataloging. An example that I made is the Coin Hoards of the Roman Empire project. This is one of the largest-scale numismatic datasets in existence, although hoard URIs cannot be reused for cataloging in the sense that machine-readable data cannot be extracted from CHRE in order to power geographic visualizations (in contrast to coinhoards.org). Making CHRE more reusable and interoperable would radically transform the research value of other, related projects, such as Online Coins of the Roman Empire. I am hoping with further technical guidance, the IT staff at Oxford can implement standardized data exports from the CHRE database to enhance external projects.

A PDF of my presentation is available at https://doi.org/10.5281/zenodo.8120871, and the presentation can be viewed at the 6 hour 39 minute mark of the livestream on YouTube.

In Athens, I presented a general introduction to Nomisma.org and conducted a live demo of using OpenRefine to normalize some Roman imperial coinage data from the Getty museum, demonstrating the Nomisma.org and OCRE reconciliation APIs. The intention wasn't to teach participants the ins and outs of using OpenRefine (which can't be done in 45 minutes), but to illustrate the sorts of tasks that can be semi-automated in preparing data for integration into Nomisma.org.

The demo presupposes that the coins are already online. We did discuss how to start from scratch. There's no easy answer to this; data still need to be inputted in spreadsheets or exported from excavation databases (for example, Microsoft Access or FileMaker) into CSV, normalized, and then imported into Numishare or the Dedalo platform. The coin finds of Sardinia are published in Dedalo, while Federico Carbone of the University of Salerno showed the Coin Finds Hub of Italy, which is presented in Numishare. In either case, IT staff are often necessary to deploy these databases on web servers and/or handle the transformation and upload of data. There's no magic bullet in publishing excavation coins online without some level of technical support. We did discuss implementing a simple spreadsheet mapping tool into NUDS that could be uploaded in Numishare.

I expect both the Coin Finds Hub of Italy (which includes the excavations of Paestum, Pompeii, and others) and the Alexandrian coins to be available online later in the fall and integrated (at least to a small degree) to type portals such as IRIS, OCRE, or PCO.

About 900 Ptolemaic and Seleucid coins from the Netherlands National Numismatic Collection added

Finally, after two years on the back-burner, I have been able to process spreadsheets sent to me by Paul Belien at the National Numismatic Museum of De Nederlandsche Bank. These spreadsheets were of DNB's Seleucid and Ptolemaic coinage, with references to Hoover's Seleucid Coins and Ptolemaic types from Svoronos' 1904 volume, Ta nomismata tou kratous ton Ptolemaion. More than 600 coins from DNB have been added into Seleucid Coins Online and more than 250 have been added to Ptolemaic Coins Online, representing approximately half of DNB's Ptolemaic collection, since only the first half of the Ptolemaic Empire has so far been published to PCO. The DNB is presently the third-largest contributor of Seleucid coins, behind the American Numismatic Society and Bibliotheque nationale de France.

A few Seleucid coins have findspots of Caesarea (in Israel), perhaps from excavations. Interestingly one Ptolemaic coin, CPE 892, a silver stater minted in Alexandria of Ptolemy IV, was found in Arnhem, Netherlands.

DNB 1960-0180, found in Arnhem

Over 1,000 coins from the Gallo-Roman Museum of Tongeren added to OCRE

This is several months late, but in January, more than 1,000 coins from the Gallo-Roman Museum of Tongeren were added to Online Coins of the Roman Empire. A large number of these coins have findspots, which have propagated into the mapping functions through the OCRE user interfaces.

What's particularly notable of this collection joining the Nomisma.org consortium is a successful technical test of the Nomisma RDF import back-end's findspot reconciliation workflow. The technical team at the museum wrote a dynamic transformation into the Nomisma RDF model that conforms to our current CIDOC-CRM inspired findspot structure. Their gazetteer system of choice is Geonames.org, and these Geonames URIs are reconciled to Wikidata.org ones upon ingestion into the Nomisma SPARQL endpoint.

 

An example of Augustus 287 with a findspot of Tongeren, Belgium

 

Although this is not a unique example, since many Iron Age British coins from the British Museum or Portable Antiquities Scheme with findspots have been uploaded into Nomisma and made accessible through Iron Age Coins in Britain, these imported Iron Age datasets were cleaned and normalized by myself in OpenRefine and stored on our web server as static RDF files. The Gallo-Roman Museum of Tongeren is therefore the first external partner to adopt the findspot model through a dynamically generated export, which enabled the testing of Geonames->Wikidata reconciliation upon ingestion.

Many other collections that may have individual findspots associated with coins have not updated their findspot RDF model accordingly.

1,400 British Museum Bactrian and Indo-Greek coins added to BIGR

Simon Glenn has recently completed the cataloging and photography of the collection of Bactrian and Indo-Greek coins in the British Museum (and these updates have propagated to the online collection). This is one of the largest collections of this genre of coins in the world, numbering a little over 1,400 specimens. At present, there are now approximately 5,400 total objects linked to the types and subtypes in the NEH-AHRC funded Bactrian and Indo-Greek Rulers (BIGR) project.

With a concordance spreadsheet of the British Museum's PRN database IDs and BIGR coin type URIs, I was able to use OpenRefine to extract data from the BM's not-publicly-documented JSON API to parse out weights, diameters, axes, image URLs, and even findspots. Although none of these 1,400 coins include a reference to published hoards in the Inventory of Greek Coin Hoards database, about 60 do have findspots listed in the BM metadata. These place names (fewer than ten distinct places in total) were parsed from the BM and reconciled against Wikidata.org entity URIs. The resulting data from OpenRefine were exported into the Nomisma.org RDF model and uploaded into the Nomisma SPARQL endpoint yesterday afternoon. As part of this upload process, the Nomisma import back-end extracted preferred labels, coordinates, and geographic hierarchy for each of the Wikidata findspots linked to the British Museum coins.

Euthydemus I 11.1 with one findspot of Bagram, Afghanistan

Since we extract the geographic hierarchy for findspots from Wikidata and import these places into the Nomisma SPARQL endpoint, it is therefore possible to query all coins found within Afghanistan, regardless of whether the place is Kabul or Bagram. For example:

SELECT ?coin WHERE {
  ?coin nmo:hasFindspot/crm:P7_took_place_at/crm:P89_falls_within+
<http://www.wikidata.org/entity/Q889>
}

 

where http://www.wikidata.org/entity/Q889 is the entity URI for the country of Afghanistan.

These finds, of course, propagate into the maps on Nomisma.org itself, for example, the page for Euthydemus I now lists individual findspots for Bukhara and Bagram.

The ANS and Oxford University launches Bactrian Indo-Greek Rulers (BIGR)

Although it has been announced informally on Twitter, our official press release was issued during the INC conference in mid-September to coincide with a paper presented by Simon Glenn and Gunnar Dumke in the digital futures of Hellenistic coinages session. This typology includes 531 types and many additional subtypes, linked to more than 4,000 total specimens from three major collections. The photographic coverage of the parent types is nearly complete, and these typologies have already been integrated into the Hellenistic Royal Coinages umbrella site, backing Bactrian and Indo-Greek coinages available through the same interfaces as Seleucid, Ptolemaic, etc.

Nomisma Updates: New partner and interlinked data

Through the KENOM project, the Coin Cabinet of the Mainz City Archives joins the Nomisma.org consortium, providing more than 60 coins to Online Coins of the Roman Empire.

In addition, more than 3,500 URIs from the IKMK thesaurus system (the Normdatenportal, or NDP) have been incorporated into Nomisma RDF, as either skos:closeMatch for mints or skos:exactMatch for other classes. The data were provided by Karsten Dahmen at the MK Berlin, and the URIs were incorporated into the Nomisma RDF with a relatively simple script.

Geographic export in Nomisma.org finally migrated from Pelagios RDF to Linked Places GeoJSON-LD

At long last, the Nomisma.org geographic export from in the nearly ten year old Pelagios RDF/XML model has been migrated into Linked Places GeoJSON-LD. The query of places from Nomisma includes all mints and regions that have a spatial extent. These places are predominately mints, as only a few regions have explicit polygon spatial boundaries. As such, the Linked Places export does not include the full geographic hierarchy between mints and regions (yet), although it may be possible to generate a bounding box of a region formed by the extent of child mint locations. The new download URL is http://nomisma.org/linked-places.json.

Another requirement of a Linked Places place is a "when" property that includes a data range and optional period URIs. These are not explicit within Nomisma, although they can be derived by the link between the mint/region and a "field of numismatics" concept URI. There are about two dozen fields of numismatics in Nomisma (e.g., Roman, Byzantine, Islamic, and Greek), and I have updated these concepts to insert URIs for corresponding periods in the DAI's ChronOntology, Perio.do, and style facets defined in the Getty Art & Architecture Thesaurus. Fields of numismatics aren't precisely periods, and so they are linked with the skos:related property rather than skos:exactMatch, which is usually implemented for linking to external thesauri from Nomisma concepts.

The date range of the "when" property is required in Linked Places. It is not currently available in the JSON export, but we are going to put a broad start and end date range into the field of numismatics concepts, which we can then incorporate into the export after minor modifications to the underlying SPARQL query. Apart from this the period "name" is not populated, since we are only storing URIs for these concepts in Nomisma, and not any additional metadata we might extract from those target information systems.

Other than these temporary deficiencies, the model is fairly fleshed out. There are about 2,000 places with geographic coordinates in Nomisma.

Linked Places Geo-JSON-LD views in the GeoJSON sandbox.

 

Hopefully this export will pave the way for Nomisma.org geographic concepts to be integrated into the World Historical Gazetteer since the old Pelagios geographic aggregation system has been deprecated.