Monday, June 29, 2020

Significant data improvement made to ANS Greek department

Last week, as I begin to transition from the basically-completed Hellenistic Royal Coinages project to publishing the Roman Republican Die Project, I took a few hours to dump a list of names that appear as authorities in the ANS's Greek department and reconcile them against's API in OpenRefine.

Of the roughly 1,000 names that appear in the Authority facet, about 600 were successfully linked to Nomisma URIs, the majority of which were generated several months ago as a precursor to the launch of the new and improved Coin Hoards database. Of the remaining 400, a relatively small number (several dozen) are names that require further disambiguation between more than one entity (multiple Cotys or Mithridates are represented in the ANS collection) or rulers that have not yet been created in Nomisma. A larger portion of the remaining 400 are Roman magistrates that will be normalized at a later date as we begin to incorporate Roman Provincial Coinage Online URIs into our database or Celtic kings or tribes that will be created in Nomisma in the near future.

The linking of authorities in MANTIS to Nomisma results in a huge improvement in the usability of our Greek coinage. This not only improves that standardization of preferred labels (since we had previously implemented variant names and spellings for the same person in the underlying FileMaker curatorial database), but Nomisma also facilitates the indexing of related dynasty and corporate entity concepts into MANTIS. The Dynasty facet on the browse page is much improved (although not thoroughly cleaned, since we did not eliminate values from this facet for coins not linked to authorities).

Parthian coins in MANTIS

More importantly, the State facet now lists all of the overarching corporate entities linked to each individual ruler, satrap, magistrate, etc. This means that for the first time, it is possible to execute a simple query to gather all 1,600 coins of the Parthian Empire, 349 coins of the Kingdom of Elymais, etc. in one result set, rather than relying on the previous dynasty field, which was inconsistently cataloged.

Some further statistics:
  • Of the 94,723 coins in the Greek department, 38,563 are linked to Nomisma URIs for authority.
  • 32,177 coins are linked to a Nomisma concept for the related corporate entity. There are 84 corporate entities in total.

There is still much to improve here, both within the Greek department and beyond it, but this is a clear demonstration of the enhancements that can be made in usability by more thorough integration of Linked Open Data identifiers. The effort to achieve this was minimal (since most of the Nomisma IDs had already been created), but is a foundation on which we can build toward better data quality within other departments as we begin to transition from FileMaker to CollectiveAccess as our collections management system.

Friday, June 19, 2020

Hellenistic Royal Coinages union monogram catalog enabled

After making some minor updates to the XQuery that underlies the symbol pages in Numishare, I have enabled the unified monogram interface in the Hellenistic Royal Coinages umbrella site. There are now 2,800 monogram URIs in this interface spread across Seleucid, Ptolemaic, and Argead coinage, including posthumous issues in the name of Alexander the Great published in the PELLA project. These monograms can be filtered by constituent letter, as in individual projects, showing overlap between the various Hellenistic kingdoms. It will become apparent that identical monograms will have different URIs in the different type corpora. This will be addressed eventually, as we combine these images with monograms from other Greek numismatic projects, such as Corpus Nummorum, and issue unique URIs for each monogram concept in the namespace.

Hellenistic monograms consisting of Χ and Ψ

Some minor updates to Numishare were made this morning to index the constituent letters from these monograms into a Solr facet that appears under the symbols section of the browse page in each project, as well as the HRC umbrella site. The letters are indexed at the level of obverse and reverse, but not specific positions, like other symbols. The Javascript that forms the Lucene query has been updated to replace the default operator from OR to AND for letters, since it is more useful to search for types related to all of the associated letters than any of them (in contrast to mints, denominations, etc., where a coin type is typically only associated with one).

Hellenistic coins with monograms that contain Χ and Ψ

Price 874
What interesting here is that there are two pairs of identical monograms in the results. One coin from each pair is from PELLA and the other from SCO. For example, Price 874 is the same monogram as Houghton 570.4. Looking at the types associated with these monograms, Price attributes one type (P151) to Philip III Arrhidaeus from Aradus, but the monogram appears on several Seleucid types. In particular, P151 appears to be identical to, which also includes an identical monogram form (also with two different URIs in PELLA and SCO) in the left field (according to the images, but not the cataloging). The cataloging in PELLA is wrong here and should be fixed. The photographs associated with the Price type clearly show these monograms in left field, and Price 399 beneath the throne (perhaps wrongly encoded as the Greek zeta in SCO).

Price P151 and SC Ad43.9 have not previously been linked together as the same type. Four coins from the Ashmolean and BnF link to the Price URI, but no coins have been cataloged to the SC number. By inserting these types into our concordance list, we will be able to display the images for the coins in SCO. Furthermore, Houghton, Lorber, and Hoover attribute this type to Seleucus, minted in Babylon. While we will not change Price's cataloging to change the authority and mint for the type, ideally we want to to use the SC data as the canonical reference.

Thursday, June 18, 2020

About 1,300 Seleucid Monograms published to SCO

About 1,300 monograms appearing on the coinage of Seleucus I through Antiochus III (Houghton, Lorber, and Hoover's Seleucid Coins, Part 1) have been published to Seleucid Coins Online (SCO) and linked to thousands of types and subtypes. Much like previous work with PELLA and PCO, the constituent letters have been annotated by Peter van Alfen, although I am sure we will spot some errors or oversights in the process.

Where the SCO monograms differ from the previous projects is that monograms have been organized hierarchically by Oliver Hoover. Unlike in PELLA and PCO, where a monogram usually has one SVG file (but may have more than one to illustrate slight variations in style), the Seleucid monograms have been grouped thematically by letters and general design motif.

SCO monogram 299

For example Monogram 299 generally consists of Μ, Ε, and Υ, and has four sub-monograms linked to the parent through skos:broader in the RDF. These sub-monograms URIs (e.g,, are encoded within the coin type data, which makes it possible to visualize the mints, hoards, and coin types connected at the sub-monogram level as well as the parent level, by extending the underlying SPARQL query all types associated with the parent monogram through each of the children:

  BIND (<> as ?symbol)
    SELECT ?symbol ?side WHERE {
     {?side nmo:hasControlmark ?symbol}
     UNION {?children skos:broader+ ?symbol .
              ?side nmo:hasControlmark ?children}

Similarly, Seleucid Coins is an extensively hierarchical type corpus. Many symbols and monograms are annotated at the subtype level. While individual subtypes are indexed into Solr in Numishare for OpenRefine reconciliation and the Atom feed (which powers lookups in KENOM), the browse page itself shows only parent types. The underlying code in Numishare was updated so that symbols and monograms annotated within subtypes are indexed into Solr, making it possible to access them from the symbol facets, regardless of whether that particular monogram appears explicitly within the data for the parent type. For example, Monogram 426 appears in SC 42.2, but has been indexed into the data for SC 42 so that it still appears on the browse page for the query, with two other non-hierarchical types in which the monogram appears directly. Coincidentally, Monogram 426 only appears on posthumous Alexanders minted in Carrhae from 310-290 B.C.

Query results for Monogram 426

Some technical advances I would like to implement in these user interfaces in the near future:

  • A histogram showing the dates of production for monograms
  • Plugging the monograms into the existing distribution analyses functions in Numishare and Nomisma (to generate charts showing authorities, mints, etc. that produced monograms)
  • Vary the radius of the mint points on the map by density of production
  • Introduce a draggable timeline into the map so that the geographic distribution can be visualized over time

The links between letters, monograms, types, mints (and other typological attributes), and hoards will open the door to completely new types of query that were not possible before the application of Linked Open Data to numismatics. We are barely scratching the surface of what's possible. I have recently queried a list of concordances between Ptolemaic monograms and mints from the SPARQL endpoint that I plan to import into a network visualization tool, like Gephi, for experimentation.

Friday, June 12, 2020

Ptolemaic Monograms Published to PCO

More than 300 monograms pertaining to the coinage of Ptolemy I - IV have been published to Ptolemaic Coins Online. Like the functionality detailed in our publication of monograms in PELLA, the monogram images will appear in the browse and coin type pages, and the landing pages for monograms, e.g., Lorber 265, will show related coin types and a map of associated mints and findspots. Since the American Numismatic Society's collection pulls typological directly from PCO, the monograms will now appear directly in Mantis.

Unlike in PELLA, where more than one monogram does not often occur in the same position on a side of the coin, the combination of monograms, letters, and other symbols may appear together, sometimes in a particular horizontal or vertical alignment.

CPE 1.1 645, for example, includes two monograms arranged vertically in the left field, and lambda over another monogram in the right.

ANS 1944.100.76207 - CPE 1.1 645

In order to handle these particular placements, as well as choices between monograms (a type may include slight variations of a monogram), we have turned to using EpiDoc TEI for more granular annotation. EpiDoc was introduced in 2017 to facilitate increased granularity for legends, descriptions, and bibliographic references. I have recently updated the NUDS XML schema to allow for the namespacing of EpiDoc into the <symbol> element to differentiate between monogram URIs and tei:segs for letters. Many other symbols that appear on coins (e.g., dolphin, torch, lightning bolt, etc.) are still encoded as segs, but we will eventually replace these with URIs representing visual concepts.

The arrangement of symbols above is represented in TEI as:

<symbol position="leftField">
    <tei:div type="edition">
        <tei:ab rend="above">
                    <tei:g type="nmo:Monogram" 
    >Lorber Monogram 206</tei:g>
        <tei:ab rend="below">
                    <tei:g type="nmo:Monogram" 
    >Lorber Monogram 265</tei:g>
<symbol position="rightField">
    <tei:div type="edition">
        <tei:ab rend="above">
        <tei:ab rend="below">
                    <tei:g type="nmo:Monogram" 
    >Lorber Monogram 104</tei:g>

The @rend element is used in the <ab> or <seg> for particular renderings, e.g., to annotation rotation.

B544 is an illustration of a choice between two monograms, a variation of sigma that is facing either direction.

<symbol position="exergue">
    <tei:div type="edition">
                <tei:g type="nmo:Monogram" 
    >Lorber Monogram 250</tei:g>
                <tei:g type="nmo:Monogram" 
>Lorber Monogram 118</tei:g>

These data are entered into spreadsheet columns following a particular standard, which the CSV-to-NUDS PHP script will parse into TEI XML. The same logic has been applied to the script for publishing Seleucid monograms. So expect to see those online in the year future.

Wednesday, June 3, 2020

Richard Abdy's new Hadrianic RIC volume published to OCRE

After a tremendous amount of work by ANS curatorial assistant, Lauren Tomanelli, and with the permission of Spink & Son and British Museum curator and author of the newest edition of Roman Imperial Coinage (Volume II, Part 3, second edition), Richard Abdy, the new coin types of Hadrian have been published to Online Coins of the Roman Empire.

The new volume includes more than 3,000 types of Hadrian, with a much more granular description of busts, we have taken a type/subtype approach to the new volume in order to minimize the reduction of physical specimens that are attributed to these types.

For example, RIC II.3 Hadrian 4-6 have three distinct busts:

  • Bust of Hadrian, laureate, bare chest, traces of drapery on far shoulder usually visible, right
  • Bust of Hadrian, laureate, cuirassed, right, viewed from front
  • Bust of Hadrian, laureate, draped and cuirassed, right, viewed from front
These three types have been derived from a single type in the original volume, 2C. Since few, if any, other collections have begun to catalog their collections in the new type numbers, if we published every type without linking Hadrian 4-6 as a supertype, we would end up losing all of the specimen data from Hadrian 2C. There is certainly a disadvantage to this approach, which can be illustrated in Hadrian 14-16:

While II.3 Hadrian 14 maps 1:1 with II Hadrian 4B, II.3 Hadrian 15 and 16 both map to one type in the first edition (4C). Therefore, the same example specimens appear under the Hadrian 15 and 16 types, not having been disambiguated by bust type in the source cataloging from partner collections. We hope these sorts of issues will be cleaned up over time.

On the other hand, the supertype strategy does open the door to archaeological materials to be attributed to the supertype, when the bust is too worn for certain identification.

The Concordance List

Lauren worked to put together a concordance list between the old and new type numbers, which we have published as a Google Sheet here. The relationship is often 1:1, but there are 1:n relationships in either direction. Under the hood in Numishare, 1:1 relationships result in an HTTP 303 See Other redirect to the new type URI. If an old URI corresponds to more than 1 new URI, the user is presented with a choice of possibilities (example, The underlying RDF data include dcterms:replaces/dcterms:isReplacedBy and skos:exactMatch properties, according to precedents we have established in other projects, like Ptolemaic Coins Online.

There are some 400 type numbers from the first edition that are not in the second, including cistophori, which have moved to Roman Provincial Coinage. We plan to create automated redirects to RPC Online for this block of about 100 types in the near future.

Tuesday, May 19, 2020

British Museum URIs updated, linked to Coin Hoards

More than 62,000 British Museum coins that have been aggregated into the 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 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.

Thursday, May 14, 2020

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's SPARQL endpoint.

Because there are a number of similarities across monograms (see 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: <>
PREFIX geo: <>
PREFIX nmo: <>
PREFIX org: <>
PREFIX rdf: <>
PREFIX skos: <>

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):

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.