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.

Esty's die calculations and frequency visualizations added to CRRO

At long last, I've had a gap between a couple of projects to spend some time developing a new feature in Coinage of the Roman Republic Online (CRRO) that Liv Yarrow and Lucia Carbone requested last winter. There is now a significant number of coins die-linked within the Roman Republican Die Project (RRDP) that this network of relationships can be used to dynamically calculate the estimated number of dies for a Roman Republican coin type in CRRO. These calculations are based on formulas in Warren G. Esty's 2006 "How to estimate the original number of dies and the coverage of a sample" and the 2011 follow-up, "The Geometric Model for Estimating the Number of Dies," with p = 1 instead of p = 2 in a later addendum.

A new API in Nomisma was created to perform these underlying calculations and respond with JSON data that are rendered into HTML with a d3.js chart in corresponding pages in CRRO. The http://nomisma.org/apis/dieCounts API executes a SPARQL query to generate a list of named graphs that correspond to die studies (in this case, Richard Schaefer's RRDP, http://nomisma.org/editor/rschaefer) and related type corpora. There is also a list of available formulas for calculating die estimates, although the only one at present is Esty's. The formulas are extensible.

The next phase of the API call once selecting a formula (http://nomisma.org/apis/dieCounts/esty) is to provide two request parameters: 'type' for the coin type URI and 'dieStudy' for the named graph URI. For example, http://nomisma.org/apis/dieCounts/esty?dieStudy=http%3A%2F%2Fnomisma.org%2Feditor%2Frschaefer&type=http%3A%2F%2Fnumismatics.org%2Fcrro%2Fid%2Frrc-336.1c

This JSON response includes the number of specimens (n), number of unique dies (d), singletons (dies that appear on only one coin, d1), estimated coverage (based on these numbers, c_est), estimated number of dies for the type (d_est, given the coverage value), and the minimum and maximum range of dies given 95% confidence.

The response includes these calculations for both the obverse and the reverse, if applicable (some types may be linked to only obverse or reverse dies, but not both). Four SPARQL queries are submitted for each side of the coin and the JSON response that results from these queries is used by CRRO to display the results in HTML and a line graph.

The SPARQL queries for the obverse dies associated with RRC 336/1c are as follows:

• Number of coins with a die: https://gist.github.com/ewg118/de29e459bde316f854b41d390081853b
• Unique number of dies associated with a type: https://gist.github.com/ewg118/9a587212964436098a47c85b8fa58faf
• Number of singletons. This is a subselect of dies connected to one object: https://gist.github.com/ewg118/d7d1d655b8e740784bed6c3886cb566d
• Frequency (how many dies are represented by how many coins): https://gist.github.com/ewg118/53ece887943761f680184ecbc02b2d12
  

The first three queries are executed before implementing Esty's die estimate calculations, which are reflected in his 2006 article (with some later revision, as noted above):

The template for applying Esty's calculations is in XSLT with some additional math functions that aren't inherent in the XSLT 2.0 spec. These templates are extensible to include proposed formulas from other scholars.

The end result for RRC 336/1c appears below:

Die estimates and frequency visualization

The frequency statistics are also downloadable as CSV.

These calculations are performed dynamically when the page is loaded, so they reflect the current state of data entry. The numbers can and probably will change over time as more data are added into the Roman Republican knowledge graph stored in Nomisma.org. In the past, it may have taken weeks or months to aggregate the data necessary to perform these calculations, which can now be generated nearly instantaneously based on tens of thousands of coins linked to both types and dies.