British Museum URIs updated, linked to Coin Hoards

More than 62,000 British Museum coins that have been aggregated into the Nomisma.org numismatic Linked Open Data cloud have had their URIs updated to the newly-launched Collections Online system. The lack of long-term maintenance of their own URI scheme has been a well-known problem for years, and hopefully the new Collections Online receives the administrative backing to promote a greater level of stability than the original experiment with SPARQL.

As part of this overhaul, my script read a JSON API for each coin to perform a lookup of new image URLs. The images provided in the new system are higher resolution than before, enabling us to store both thumbnail and maximum resolution image links. In some cases, we have been able to prefer obverse and reverse images over jpegs where these sides had been combined into one file.

In addition, I performed a lookup for Greek coins with "hoard" as a keyword. I downloaded the CSV for these search results (1,600 coins), and was able to link about 1,400 of them to URIs in coinhoards.org. Surprisingly there was zero overlap between Hellenistic coins from the BM that were already in PELLA, SCO, and PCO and coins with hoard references. I imagine this is a gap in cataloging. I also used OpenRefine to reconcile mints, denominations, and materials to Nomisma URIs so that these values can be used for more sophisticated query.

A British Museum coin linked to IGCH 1648.

These 1,400 coins have been linked positively to 38 IGCH hoards, including seemingly complete coverage of IGCH 2194, a hoard consisting exclusively of Carthaginian bronzes. The British Museum's cataloging suggests these were all minted in Carthage, but IGCH suggests an uncertain Siculo-Punic mint.

About half of all of the coins with an IGCH reference come from IGCH 1355, a substantial hoard of Rhodian silver coinage. Sadly, few if any have been photographed so far.

More than 1000 monogram URIs added to more than 2,000 types of Alexander the Great

Back in December, more than 1,200 monograms from Price's 1991 monograph, Coinage in the Name of Alexander the Great and Philip Arrhidaeus, were published into PELLA, each accessible at a URI with at least one SVG graphic (drawn by Mark Pyzyk) representing an idealized representation of that monogram.

Recently, we processed a concordance between these monogram IDs and their associated Price type numbers (also prepared by Mark) and regenerated the entire Price data in PELLA. The result is nothing short of major advancement in the way researchers can query and visualize these monograms over time and space.

Fig. 1: monogram facets

Let's first begin with the browse page, where the symbol facets (expand the list below the typological categories) have been updated for these monograms. The multiselect widget supports rendering HTML, which means we can display the SVG graphic in the symbol list (Fig 1). If we select one or more monograms to filter our search results, the graphic will also display in the list of filters to be removed (Fig 2).

Fig. 2: search results

Connecting all of the dots in the numismatic LOD graph

Monogram 453 is one of the more interesting test cases.

Of course the monogram will appear on a type page which contains that monogram, e.g., Price 210, and it will also appear in MANTIS as well, since MANTIS (and other Numishare-based projects) will pull typological data from a coin type record. The ANS coin, 1944.100.29329, has a type of Price 210, but was also found in the the Demanhur Hoard (IGCH 1664), which now enables us to establish a direct link from specimen -> hoard (with findspot) -> type (with mint) -> monogram. Since this monogram appears on many types which are linked to many specimens from various hoards, we can therefore generate a map showing the geographic distribution of both production and circulation of this monogram. We can also get a full list of types on which this monogram appears. We can see that it was overwhelmingly produced from 336 - 300 B.C., but still produced in Miletus as late as 165 B.C.

Fig. 3: Monogram 453

The next logical step for this is to expand the map to include a histogram reflecting both periods of production and the deposit dates of the related coin hoards. The hoard GeoJSON is already GeoJSON-T compliant.

Furthermore, since Price types have been annotated, you can see Edward T. Newell's own sketch for this monogram in one of his own research notebooks in our digital archive (powered by TEI - IIIF interoperability).

Page 19 of one of Newell's hoard notebooks.

Because we have captured constituent letters of these monograms (using CIDOC-CRM, as detailed in the December blog post), it is possible to take these visualizations one step further by showing the distribution of a particular letter or combination of letters over time and space. Although we have not adapted the Numishare user interface to query and visualize by constituent letters yet, it is nevertheless possible to conduct these queries directly in Nomisma.org's SPARQL endpoint.

Because there are a number of similarities across monograms (see http://numismatics.org/pella/symbols?symbol=%CE%94&symbol=%CE%97 for monograms with Η and Δ), perhaps we would like to query for all mints that contain monograms that include both of these letters:

PREFIX crm: <http://www.cidoc-crm.org/cidoc-crm/>
PREFIX geo: <http://www.w3.org/2003/01/geo/wgs84_pos#>
PREFIX nmo: <http://nomisma.org/ontology#>
PREFIX org: <http://www.w3.org/ns/org#>
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX skos: <http://www.w3.org/2004/02/skos/core#>

SELECT DISTINCT ?mint ?label ?lat ?long WHERE {
  ?monogram crm:P106_is_composed_of "Δ", "Η" .
  ?side nmo:hasControlmark ?monogram .
  ?type nmo:hasObverse|nmo:hasReverse ?side
  {?type nmo:hasMint ?mint}
  UNION {?type nmo:hasMint/rdf:value ?mint}
  ?mint a nmo:Mint ;
        geo:location ?loc ;
        skos:prefLabel ?label FILTER (langMatches(lang(?label), "en")) .
  ?loc geo:lat ?lat ;
       geo:long ?long
} 

Distinct mints with delta-eta (results)

Or perhaps we want to see not just the distinct mints, but the full list of types (mapped) and ordered chronologically (query):

https://tinyurl.com/y7puekgg

Broad distribution of delta-eta monograms, grouped geographically by number of types

What we see here is that eta and delta monograms first appear in Miletus about the time of Alexander's death before circulating around neighboring cities in Asia Minor, then substantial production in Ecbatana from 295-280 B.C., and then two notable periods in Odessus in 200 B.C. and again in 70.

Next Steps 

The obvious next step is to upgrade the interface of the symbol page to generate a map of mints and findspots for a given letter combination, as well as provide links to download related coin types and physical specimens. This is fairly straightfoward and can be implemented within the next several days.

Currently, Lauren Tomanelli (having finished her work on the new Hadrian volume of RIC) is working on preparing the Ptolemaic monograms for publication, and Oliver Hoover is doing the same for the Seleucids. Seleucid Coins Online and Ptolemaic Coins Online will be reprocessed with these new URIs, and so this functionality will become available in both of those projects, as well as in the Hellenistic Royal Coinages umbrella site. There will be some duplication of monogram forms across these corpora. In the longer term, the Greek numismatists working within the Nomisma community will disambiguate these monograms and issue a new URI pattern directly in Nomisma for each distinct monogram. Old, duplicate URIs from HRC will point to the new scheme.