This paper addresses the ongoing development by the American Numismatic Society (ANS) of an XML ontology for coins, the Numismatic Descriptive Standard (NUDS), and an open-source collections management and publication application, Numishare (http://code.google.com/p/numishare/). Both are greatly influenced by the tenets of linked open data. In order to facilitate interactions between systems, concepts are represented as URIs hosted by http://nomisma.org. Nomisma.org is a collaborative effort to provide stable digital representations of numismatic concepts and entities. It provides URIs for such basic concepts as 'coin', 'mint', 'axis'. All of these are defined within the scope of numismatics but are already being linked to other stable resources where available. For example, URIs that represent mints are linked via the SKOS ontology to the Pleiades Gazetteer of ancient places. Moreover, concepts may contain as many labels in alternate languages as necessary, making it possible to aggregate search results across multi-lingual collections. Numishare leverages APIs provided by nomisma.org to create rich numismatic metadata, but can also use geonames.org URIs for modern places and the Virtual International Authority File (viaf.org) for personal and corporate names.
The ANS project, Online Coinage of the Roman Empire (OCRE), is a proof of concept of this system. Roman coinage is one of the richest bodies of material in existence for the study of the art, economy, and social life of the ancient world. Although ancient coins have been catalogued and classified in print, existing online databases are partial, unconnected or inconsistent with one another. An authoritative and complete type-corpus of Roman coinage is available in libraries in the form of the ten volumes of Roman Imperial Coinage, which identifies 47,000 discrete varieties. But this resource cannot be found everywhere, is extremely expensive to purchase and, since it is split across multiple volumes, is impossible to search easily as a whole. It is the aim of this project to create the first online type corpus of Roman coinage. OCRE will provide an illustrated listing of all known varieties of Roman coinage of the imperial period, from Augustus in the first century BC to Anastasius in the fifth century AD, in a format that can be searched by emperor, place of production, designs, legends, denominations and metals used. Inherent in the design is the ability to append to the basic type record the details of specimens in collections represented online. Thus it will be possible to accumulate quantitative data, such as weights or metal content of individual specimens, to aid in the construction of data sets usable for statistical analysis of Roman coinage.
The system will provide for information about coin hoards and finds, and it will be integrated with the leading online information source for ancient geography, Pleiades, knowing that it could be potentially linked to any relevant electronic platform or database dealing with the ancient world.
