Bernoulli-Euler-Digital with RDF-star-based Digital Edition of Jacob Bernoulli’s Travel Diary, Reisbüchlein

Bernoulli-Euler Digital application is a notable expansion of the Bernoulli-Euler Online (BEOL) project containing an interactive region-based digital edition of Jacob Bernoulli’s travel diary, Reisbüchlein, created using the RDF-star and SPARQL-star technologies. This platform serves as a dedicated research hub, focusing on exploring early modern mathematics and science. Its primary objective is to seamlessly integrate the extensive works and correspondences of the prominent members of the Bernoulli dynasty and the influential mathematician Leonhard Euler.

The knowledge graph of the Reisbüchlein edition is constructed using the JourneyStar ontology, an open-access ontology we developed to thoroughly and efficiently represent travel data by connecting metadata information such as dates and sources of information to the graph's edges. The ontology and its SHACL shapes, necessary for validating the graph data, are open-access on GitHub. The edition is created semiautomatically by using the textToRDFGraph pipeline to extract information from diary entries and represent the textual content in a machine-readable format. For this purpose, transcriptions generated using Transkribus and verified by the project team are used as the pipeline's input. This ontology-driven NLP pipeline retrieves the information from unstructured text and enriches the edition’s RDF-star graph with named entities and relations found between the entities. The RDF resources representing locations and persons given in the text are connected to their representation on the Wikidata and DBpedia repositories to allow the discovery of the information by following the nose principle. Thus, instead of creating yet another data silo of locations and persons, the named entities of the edition are connected to the third-party repositories and data is retrieved from these repositories upon access through federated searches. For example, for journey visualizations available on the web application, the coordinates of the origin and destination of journey stages are retrieved dynamically from Wikidata and used to create web-based visualizations.

The digital edition of all entries in the Reisbüchlein manuscript is presented in the Bernoulli-Euler Digital application with the facsimile of the pages, page transcriptions, interactive regions of the facsimile, and region transcriptions. The transcriptions contain all text markups and links to embedded named entities stored in the triplestore as standoff markups. This allows for analysis of the information using SPARQL, which enables queries for the texts about the embedded markups. For example, the user can query for all pages mentioning Geneva or all texts in which a certain phrase is written in italics.

Jacob Bernoulli described each of his journeys as an entry in Reisbüchlein with information about the duration, accommodations, events, means of transportation, costs, etc. The journeys are represented as RDF resources, with all main statements describing the journeys. The metadata are all added to the graph's edges with RDF-star statements. Upon accessing an entry through the web application, it retrieves the journey information from the triplestore vis SPARQL-star queries and displays it in a user-friendly form.