Friday, September 24, 2021

More than 2,000 coins of Hadrian from the British Museum added to OCRE

I have received a major update from Richard Abdy, curator at the British Museum and author of the most recent RIC volume on Hadrian, which was published to OCRE in June of 2020. Nearly 2,300 coins from the British Museum have been linked to Hadrian type URIs in the new volume, an increase by about 2,000 over the relatively small number of Hadrianic coins the BM had previously contributed to OCRE. The photographic coverage of Hadrian types is nearly complete. There are, in fact, about 850 types where the British Museum specimen is the only photographed example: about one-quarter of all Hadrianic coin types.

Furthermore, I queried the BM's API for each coin to extract IIIF service URIs, when available. This extended to all of the BM's contributions to the ecosystem (Iron Age, Hellenistic, and Roman coinage), and about 16,000 of the 72,000 total coins from the British Museum have zoomable IIIF images.

A British Museum example of Hadrian 103

The British Museum's API for individual objects is not publicized, but I happened upon it by looking at the console in Firefox to locate the British Museum's IIIF URI pattern (which is also not publicized). The ID portion of the object URI serves as the 'id' request parameter for the API, e.g.,

The IIIF URL is 'zoom' property for each 'processed' in the 'multimedia' array. This is a relative path that should be appended to The other static jpg files paths are appended to

Frustratingly, the object metadata are not encoded in the JSON response as clean and machine-readable. It is possible to parse data from the escaped HTML in 'xtemplate', but it requires a little clean-up. I was able to parse the measurements for the Hadrianic coins from the xtemplate for the Hadrianic coins in OpenRefine, since they weren't in the the spreadsheet export I had received.

Thursday, September 2, 2021

Improved geographic context for other Nomisma concept types

I have made some modifications to the underlying SPARQL queries to improve the geographic distribution of regions and dynasties in

Previously, a map for a region would show points for coin hoards that contained a coin explicitly from that region. However, it did not exploit the inherent geographic hierarchy expressed by skos:broader between mints and parent regions. For example, there are numerous hoards that contain coins from Syracuse, but the map for Sicily did not show them, except for a small handful of hoards that contained Sicilian coins from an uncertain mint (_: nmo:hasRegion nm:sicily). As illustrated below, the coverage for Sicily has been expanded well beyond the two hoards previously depicted to numerous examples: most in Sicily, but others elsewhere in the Mediterranean and one as far as modern Iran.

Geographic distribution of hoards with coins from Sicily

Similarly, maps for dynasties now include points for hoards associated to rulers through their relationship to dynasty URIs with org:memberOf.

Distribution of the Seleucid Dynasty before update
Seleucid Dynasty after update

One other minor update was to enable the display of findspots and hoards on the map for collections. As you can see, the American Numismatic Society has fairly good coverage within Greek coin hoards.

Mints and hoards associated with the ANS collection

Wednesday, September 1, 2021

Updates to Associated Types in Nomisma

For quite a few years (going back to about 2016), the concept pages for many types of IDs in have shown a table of example types related to the given concept, with photographs of related specimens related to the type, if available. This table was limited to 10 results, but the entire type listing could be downloaded as a CSV file.

After a minor overhaul, I have implemented pagination of these types as well as sorting for the columns of authority, mint, denomination, and date (by earliest date of issue). This enhances the overall usability of the feature.

Examples of staters, ordered alphabetically by authority


In addition, I updated the underlying SPARQL queries for deities defined in Nomisma to display both maps depicting the geographic distribution (mints, hoards, and individual findspots) and related types. The metrical and distribution analysis charts are now available for deity concepts, so it is possible to generate a chart showing the distribution of Hellenistic kings that issued coinage of Zeus, for example.

Distribution of rulers that issued types of Zeus

Tuesday, August 31, 2021

Winterthur joins

The M├╝nzkabinett Winterthur is the most recent institution to join the consortium, through their collaboration with the NUMiD framework of German numismatic databases spearheaded by the MK Berlin.

One of the largest collections in Switzerland, it is just getting underway in its digitization program, with about 250 coins cataloged and photographed in its online database. Of these, 20 have been linked to existing Nomisma-affiliated Linked Open Data projects, such as Online Coins of the Roman Empire, Hellenistic Royal Coinages, and Inventory of Greek Coin Hoards.

Winterthur coins in IGCH 1419, found in Cappadocia.

Winterthur G 5677, linked to a Ptolemaic type from Alexander

We expect that more of Winterthur's coins will be integrated into these research portals as cataloging continues over the years.

Furthermore, Winterthur will be one of the major contributors to OSCAR, the type corpus of Swiss coinage from all periods. Specimens will be integrated into OSCAR from several collections in the coming months.

Tuesday, June 22, 2021

Consolidated GeoJSON for Nomisma concepts

For many years, maps on have shown a map for many types of numismatic concepts. At first, this map was restricted only to showing a single point for a mint, and the eventual adoption of a SPARQL endpoint and aggregation of typological, hoard, and find data enabled the query and display of many types of geographic features associated with a wider variety of concepts. Associated mints, hoards, and individual findspots were requested by Leaflet in three different API calls, and this created some limitations in applying variable styling based on density of distribution after AJAX loading completed while simultaneously binding the layers together in a group to zoom to the full map bounds, since the three API calls may take different amounts of time to respond.

After a few days of work, I have implemented a new singular GeoJSON response that can be accessed via content negotiation for the "application/vnd.geo+json" content type or appending ".geojson" to the concept URI. This singular GeoJSON response is easier to manipulate further after loading, and now both the mints and finds layer display differently sized circles based on the density of objects or types produced or found at a particular geographic location. This makes it much easier to spot the mints that produced the largest volume of coinage for a particular ruler, denomination, etc. The map below illustrates the distribution of mints that produced coinage of Alexander the Great as authority, stated authority, or portrait (the numbers are based on the number of types, not specimens), with Amphipolis and Pella as the mints producing the largest number, unsurprisingly.

Map of Alexander the Great

Wednesday, June 9, 2021

Network graph visualizations for Hellenistic monograms

I have recently unveiled a new data visualization feature in Numishare that has the broadest impact in the Hellenistic Royal Coinages project, with its thousands of monograms: a network graph of the relations between a monogram and associated monograms that appear on the same types. This is formed by a SPARQL query (below) that is serialized by XSLT into the JSON model for the d3plus Network vis. A secondary iteration of queries is executed to generate an additional level of nodes related to each monogram associated directly with the root URI. In theory, you could iterate beyond this secondary relationship, but it's probably unnecessary for the purposes of a simple visualization. These data could be loaded into a desktop network analysis tool such as Gephi for more sophisticated display.

  BIND(<> as ?symbol)
  ?type nmo:hasObverse/nmo:hasControlmark|nmo:hasReverse/nmo:hasControlmark ?symbol .
  ?symbol skos:prefLabel ?symbolLabel ;
          crm:P165i_is_incorporated_in ?image .
  ?type nmo:hasObverse/nmo:hasControlmark|nmo:hasReverse/nmo:hasControlmark ?altSymbol . 
          FILTER (?altSymbol != ?symbol).
  ?altSymbol skos:prefLabel ?altSymbolLabel ;
          crm:P165i_is_incorporated_in ?altImage .        

Visualization of Price monogram 222

This network graph is a novel approach to investigating the potential meanings of these symbols, as it allows for the exploration of patterns that were never previously observed, at least at the scale that we are able to present in the HRC project. The thickness of the edges is dependent upon the number of types that share relationships. Therefore, monogram 769 and 55 share numerous types. I am still working on making some stylistic tweaks to the display.

There are two major areas of completeness that will be addressed in the future:

  1. In the process of developing this visualization, it has become apparent that there are numerous gaps in the typology where monogram URIs have not been inserted into the Price spreadsheet (and perhaps the Ptolemaic and Seleucid ones as well), so the monogram network visualization isn't necessarily a full accounting of all relationships.
  2. We have not yet gone through the monograms of the three major corpora to link the same symbol together into a cohesive, distinct set of monogram URIs. We know that the same monograms appear in Price on Alexanders as those that appear on the coinages of the Seleucids and Ptolemies, but they are not joined together. Therefore, the network visualizations in PELLA don't necessarily include monograms from Seleucid Coins Online or Ptolemaic Coins Online, unless they overlap with a small selection of early Seleucid or Ptolemaic types that were struck in the name of Alexander the Great.

One other recent enhancement is the implementation of a GeoJSON serialization for a monogram (appending .geojson to the monogram URI or requesting the content-type 'application/vnd.geo+json' via HTTP content negotiation). This GeoJSON is formed by three distinct SPARQL queries to get the mints, hoards, and findspots associated with a monogram URI. While this map did exist already, the enhancement includes the numeric counts of mints or findspots, which are stylized into differently-sized bubbles in Leaflet.

Price Monogram 1090 is one of the geographically best-represented symbols, particularly prominent in East Greece and the Black Sea. Adding a histogram of issue dates would be a useful tool in the future.

The next phase of development will be to include distribution visualizations in order to generate charts that show the numbers of denominations, mints, authorities, etc. that issued types that depict these monograms.

Thursday, May 27, 2021

American Numismatic Society joins Iron Age Coins in Britain

The American Numismatic Society has a modest collection 65 coins that have been identified and cataloged with Ancient British Coins numbers published by the Oxford Institute of Archaeology's Iron Age Coins in Britain project. Only a few of these have been photographed so far. Much like the ANS's integration with our only published digital type corpora, MANTIS pulls typological data and associated Nomisma linked open data in real time in order to display more complete and accurate data than our own internal cataloging, making it possible to display maps and use standardized terminologies for rulers, "tribes," denominations, etc. for faceted browsing.

Joined with the modest collections from Berlin and Paris and the massive collections from the British Museum and Portable Antiquities Scheme (which includes part of Oxford's Celtic Coins Index), there are nearly 40,000 individual specimens linked to Iron Age British coin types.