Harvard Art Museums added to BIGR

Thanks to the work of Simon Glenn (Ashmolean Musem, Oxford) and Laure Marest (Harvard Art Museums), 19 coins from Harvard Art Museums have been added to the Bactrian and Indo-Greek Rulers (BIGR) project. HAM is the 10th contributor to the project, which now contains links to more than 5,700 specimens.

A Harvard coin depicted at Euthydemus I 2.15

A spreadsheet of Harvard -> BIGR URI concordances and some basic metadata allowed me to load the spreadsheet into OpenRefine in order to extract the IIIF image and manifest URIs and export the resulting data directly into Nomisma-compliant RDF using a template. This is a departure from earlier iterations of the workflow which necessitated writing a PHP script to harvest data from the API and attempt to automate the matching of type references to URIs.

New Nomisma project partners are increasingly creating their own RDF/XML exports for ingestion into the Nomisma SPARQL endpoint or providing spreadsheets already embedded with coin type URIs, enabling a more seamless transformation into RDF through minor OpenRefine cleanup and template exports. Writing scripts to harvest and parse human-written references into URIs is increasingly a process of the past, although this is still necessary for one of Nomisma's largest contributors.

More than 4000 monograms published to Nomisma

After a tremendous amount of work over the last year or more, just over 4,000 monograms that appear on Greek coinages have been published as unambiguous URIs on Nomisma.org. These monograms constitute a combination of symbols that appear on Hellenistic Royals Coinages (HRC) and Corpus Nummorum (CN). Using Computer Vision methodologies employed by Karsten Tolle, identical monograms were matched across datasets, reducing the number of monograms published by both projects from 4,500 to 4,000. The potential matches were vetted by Peter van Alfen and Ulrike Peter. The monogram URIs in HRC and Corpus Nummorum have been integrated as skos:exactMatch properties in Nomisma, making it possible to create UNION SPARQL queries that enable the querying of types (and associated Nomisma concepts) across these disparate projects. This is a huge advancement in our ability to study Greek monograms and their meaning on coinage. Even in Hellenistic Royal Coinages, we did not have the time in the first phase of the project to disambiguate identical monograms across PELLA, SCO, and PCO, which limited the data and geographic visualization of monograms within their own typological silos. 

The user interfaces in Nomisma.org have been extended to include many of the features for symbols in the Numishare platform which publishes HRC: 

• The Nomisma.org browse page can be filtered to display results only for the http://nomisma.org/symbol/ namespace, and once this filter is active, a user can refine the search results by Greek and Latin (or other) letters which appear within the monogram. It is possible to switch to a grid view that makes viewing monograms more intuitive. If constituent letters have been selected, it is possible to display a map in a popup window that contains the mints, hoards, and individual finds associated with the monogram.
  

The Nomisma.org browse page showing monograms that consist of several Greek letters.

• The page for each monogram will show associated mints, hoard, and findspots. The size of the mint points vary by the number of types that produced the monogram.
• The page will show a network graph rendered in d3 showing the relationship between that monogram and other monograms that appear on associated coin types. By default, the network graph shows the most immediate relationships, but it is possible to click another button to view the secondary relationships.

The distribution map and network graph of Monogram 1830, uniting different Hellenistic typologies.

• A list of types (and photographic examples, if available) will appear. The type list is downloadable as CSV and sortable by several categories. 
• The SVG graphics associated with each monogram are in the Public Domain and can be reused for both commercial and noncommercial publication.
  

It should be noted that although thousands of monograms from CN have been published and integrated into Nomisma, we have yet to reindex the coin type data from CN that includes their own monogram URIs. As a result, the data visualizations and type lists in Nomisma only reflect HRC. Corpus Nummorum type data will be reingested into Nomisma's SPARQL endpoint in the near future.

After publishing the RDF derived from the HRC and CN monogram data, the network graph query is formed by querying a monogram of a particular URI (or its skos:exactMatches) which appear on the obverse or reverse of a type, and extending those type queries by including other monogram URIs will appear on those same types (filtering for matches that conform to the Nomisma symbol concept scheme).

SELECT ?symbol ?altSymbol ?image ?altImage WHERE {
  BIND (<http://nomisma.org/symbol/monogram.01830> as ?symbol)
  {?side nmo:hasControlmark ?symbol}
  UNION {?side nmo:hasControlmark ?match .
    ?match ^skos:exactMatch ?symbol}
  ?type nmo:hasObverse|nmo:hasReverse ?side .
  {?side nmo:hasControlmark ?altSymbol}
  UNION {?side nmo:hasControlmark ?altMatch .
  ?altMatch ^skos:exactMatch ?altSymbol }
      FILTER (?altSymbol != ?symbol 
        && contains(str(?altSymbol), "http://nomisma.org/symbol"))  
  ?symbol crm:P165i_is_incorporated_in ?image .
  ?altSymbol crm:P165i_is_incorporated_in ?altImage .
} 

Such queries can be extended to list mints or authorities which produced them, and how many types in total are associated with those concepts. By associating types with Nomisma concepts for denominations, materials, mints, individual rulers or broader political organizations, it is possible to query and visualize relationships between entities in complex ways that simply could not be undertaken before applying Linked Open Data principles to numismatics.

Once the Corpus Nummorum data have been updated in Nomisma, I will prepare a second post discussing more complex use cases with mints and authorities.

Most of the ANS collection migrated to CollectiveAccess

Several weeks ago, the North American department was migrated from the ANS' old FileMaker curatorial database into our new CollectiveAccess database system. The intermediate clean-up work was substantial and undertaken in OpenRefine by Sami Norling, who is now a data scientist for the Smithsonian Institution.

There is substantial overlap between the persons who appear on or are responsible for the issue of coinage (including designers) between North American and Medals and Decorations, and much care was taken to disambiguate between these entities and those already created in ColletiveAccess in previous department migrations. There is also quite a large number of corporate organizations responsible for issuing tokens, notes, etc., which has gone through a rigorous normalization process to standardize names and link to Wikidata.org, when possible. The resulting quality of the North American department is substantially improved (especially when linking places to Geonames.org), which is plainly visible when using the Mantis browse page and clicking on individual object links.

To date, Sami has completed the Islamic, South Asian, and North American departments, which have all been imported into CollectiveAccess and republished to Mantis. Sami has also just completed her work on the Latin American department, which will be prepared for upload into Mantis within the next few weeks.

I completed Medals & Decorations a year ago, and Greek, Roman, and Byzantine in May, which I blogged about here and here.

Only East Asian, Medieval, and Modern European departments remain to be migrated, which will hopefully conclude by the end of this year.

Symbols and monograms on Nomisma.org

Several years ago, the Nomisma scientific committee made a decision to create a new namespace in which we would publish URIs for symbols that appear on coins (including monograms): http://nomisma.org/symbol/.

Only recently have symbols been added into this namespace, primarily religious symbols that appear on Medieval coinage. At present, these symbols link to SVG graphics hosted by the Wikimedia foundation. By the end of the year, there will likely be thousands of Greek monograms added into Nomisma, disambiguated from identical glyphs between across the Hellenistic Royal Coinages (HRC) and Corpus Nummorum typologies. This is especially important since the same monograms in PELLA, Seleucid Coins Online, and Ptolemaic Coins Online are not interlinked, even when not factoring in the integration of a project external to the HRC umbrella.

The Nomisma.org browse page now includes a new filter for Concept Scheme, enabling users to sort between only those in the /id/ namespace and the /symbol/ namespace. If the /symbol/ namespace is selected in the query, additional query options become available.

Adjacent to the pagination buttons are buttons that enable changing the view from the typical list layout to a grid, which is better for perusing the symbol graphics. Additionally, it is possible to filter monograms by constituent letters, much like in the symbol interfaces in Hellenistic Royal Coinages. A user can select one or more letters, whether Latin, Greek, or another script, to filter the monograms to those containing those letters. The perceived letters are, of course, somewhat subjective based on the specialist who undertook the work of manually itemizing them.

At present, only 2 of the 13 symbols published in Nomisma are monograms (chi-rho and tau-rho Christograms), so there is a very limited range of available letters for filtering. That will change once Greek monograms are added into the Nomisma namespace.

 

Extensions for displaying symbols in Nomisma.org browse page

Once these symbols are connected to typologies integrated as Linked Open Data into the Nomisma SPARQL endpoint, I will be able to generate lists of relevant types and maps depicting the mints, findspots, and hoards associated with them, which will create a more complete picture of their distribution over time and space, a more significant advancement in data visualization as compared to the relative silos of the HRC sub-projects.

CEAlex excavation coins added to Ptolemaic Coins Online

Yesterday, the excavation database of Centre d'Études Alexandrines (CEAlex) was publicly launched, and today the relevant Linked Open Data has been imported into Nomisma.org. This new project currently includes the coins from the Cricket Ground excavations of Alexandria, which lasted from 1994-97. The nearly 300 coins published so far range in date from the Hellenistic period through Roman into Byzantine; more than 50 link to coin type URIs published in various platforms, primarily Ptolemaic Coins Online.

These excavation coins therefore enrich the research potential of PCO, providing findspots for dozens of coin types, which, in turn, expand the geographic visualization of related Nomisma.org concepts. You can learn more about the project by clicking the database link above.

CEAlex coin 3868 in Coins of the Ptolemaic Empire B196

Updated distribution map of Ptolemy II in Nomisma.org

158 Bactrian coins from the Dutch National Collection added to BIGR

Recently, Simon Glenn and Gunnar Dumke identified the Bactrian and Indo-Greek coins in the National Numismatic Collection of the Netherlands at De Nederlandsche Bank, linking them to URIs in the Bactrian and Indo-Greek Rulers (BIGR) project. These 158 new coins bring the total number of objects linked to the typology to 5,670, adding the sole photographic example for at least a handful of types.

Apollodotus II 17.3, with one NNC-DNB example: RE-00076

Greek Department updated in Mantis

 At long last, the Greek department at the American Numismatic Society (nearly 100,000 objects) has been migrated into CollectiveAccess and updated in our public database, Mantis. The coverage of people, political organizations, denominations, dynasties, etc. among Greek coinage has almost complete coverage in Nomisma.org, and the overall data quality, consistency, and completeness is greatly improved over the previous version of the data from the ANS's decades-old FileMaker database.

Almost 9,000 coins from this department have been linked to URIs published by RPC Online, which has enabled us to incorporate issuer URIs from RPC Online into Mantis, as well as fill gaps in cataloging, such has missing legends and type descriptions, which had not previously been inputted into FileMaker.

Due to the links from people to dynasties and political entities inherent in Nomisma.org linked data, we have been able to leverage these relationships and fill in missing fields, making it possible to search all coins of Parthia, even if only the ruler had previously been named on the coin.

One of the most important advances in data quality is the normalization of many findspots to places defined by Geonames, enabling the extraction of coordinates from Geonames for display in various map interfaces, either for the map showing the mint and findspot for a particular coin, or indexed in Solr for aggregate queries across the entire ANS collection. Over 150 coins in the Greek department are single finds or from excavations. Additionally, hoards are now indexed for query and geographic visualization. Several thousand Greek coins had references to Inventory of Greek Coin Hoards (IGCH) coin hoards which had not been successfully linked to URIs in Coinhoards.org, and so some gaps had been filled. Over 10,000 coins in the department (10% of the ANS's Greek collection) come from IGCH hoards and are therefore mappable in various user interfaces in Mantis. Mints, findspots, and hoards are all available in the Mantis maps interface, and can be refined by various faceted search queries. Point sizes vary based on density of coins related to those places.

Map depicting geographic distribution of Greek department

Some hundreds of Greek coins had previously slipped through the cracks in automated linking to Hellenistic Royal Coinages type URIs in the previous FileMaker-to-Mantis PHP script (due to typos or other inconsistencies that failed to match regular expressions). These have been identified and linked using OpenRefine.

After the republication of the newly-cleaned Greek and Roman departments to Mantis, the RDF export has been refreshed in Nomisma.org, adding several thousand new coins linked to type and coin hoard URIs, as well as propagating individual findspots into Hellenistic Royal Coinages, Online Coins of the Roman Empire, and Coinage of the Roman Republic Online. In total, more than 90,000 Greek and Roman coins have been ingested into the Nomisma SPARQL endpoint, an increase in more than 20,000 due to the integration of RPC Online URIs into our CollectiveAccess database. It should be noted that the RPC Online typology Linked Open Data have not been loaded into Nomisma, so it isn't possible to conduct sophisticated queries on Roman Provincial Coinage within the Nomisma LOD ecosystem (yet).

RIC Trajan 9 depicting findspots from Larnaca, Cyprus.

Aggregate distribution map of imperial coinage issued by Trajan (findspots from Portable Antiquities Scheme and the excavation of Larnaca, Cyprus)