Adrien Barbaresi
email: adrien.barbaresi@oeaw.ac.at

Placenames analysis in historical texts: tools, risks and side effects

This article presents an approach combining linguistic analysis, geographic information retrieval and visualization in order to go from toponym extraction in historical texts to projection on customizable maps. The toolkit is released under an open source license, it features bootstrapping options, geocoding and disambiguation algorithms, as well as cartographic processing. The software setting is designed to be adaptable to various historical contexts, it can be extended by further automatically processed or user-curated gazetteers, used directly on texts or plugged-in on a larger processing pipeline. I provide an example of the issues raised by generic extraction and show the benefits of integrated knowledge-based approach, data cleaning and filtering.

Introduction

In Western tradition, a current of reflexion whose origin can be dated back to the 1960s has provided the theoretical foundations of the spatial turn, whose epitome is the concept of space as emergent rather than existing a priori, and composed of relations rather than structures. As a consequence, both the definition and the importance of space have been re-evaluated throughout the humanities. More recently, researchers have suggested the crossing of research objects between disciplines and the enforcement of the "spatial turn" in practice through specific methods of analysis. Even so, corpus linguistics and geographical information systems have traditionally had very little to do with each other, although both approaches can benefit from each other [START_REF] Gregory | Visual GISting: Bringing together corpus linguistics and Geographical Information Systems[END_REF].

Distant reading practitioners employ computational techniques to mine the texts for significant patterns and make statements about them [START_REF] Wulfman | The Plot of the Plot: Graphs and Visualizations[END_REF]. From the point of view of computational linguistics, toponyms are a particular kind of out-ofvocabulary tokens. On lexical level, they are a potential error source for natural language processing tools. On phrasal level, they are supposed to be identified by part-of-speech taggers as named entities or eventually by more fine-grained named-entity recognition tools as placenames. The processing chains usually stop at this point, they do not provide visualizations in the geographical sense, even if the toponyms can be linked to meta-information such as type and georeference and although progresses in fulltext geocoding are tightly linked to progresses in mapping systems, mostly thanks to a technology-driven evolution [START_REF] Juvan | From spatial turn to GIS-mapping of literary cultures[END_REF]. On the other hand, publicly available geocoding solutions do not usually come with interfaces to linguistic methods such as disambiguation and/or annotation layers. Finally, existing cartographic software solutions are not typically built for the visualization of digital text collections.

This article summarizes issues related to historical texts and describes an effort to conveniently go from texts to maps by integrating several key steps in a modular software package: data curation and preparation, processing of linguistic corpora, geocoding, and projection on maps. The use of a toolkit creates a common ground for hypothesis testing and visualization, while at the same time being compatible with other software in terms of formats and software environment. I provide an example of the issues raised by generic extraction and show the benefits of integrated knowledge-based approach, data cleaning and filtering.

Previous work

Among the tendencies in geographic information retrieval and geocoding [START_REF] Melo | Automated Geocoding of Textual Documents: A Survey of Current Approaches[END_REF], the extraction and normalization of named places, itineraries, or qualitative spatial relations, as well as the extraction of locative expressions are particularly relevant to study text collections. In the field of information retrieval, named entity recognition defines a set of text mining techniques designed to discover named entities, connections and the types of relations between them. The particular task of finding placenames in texts is commonly named placenames extraction or toponym resolution. It involves first the detection of words and phrases that may potentially be proper nouns and second their classification as geographic references [START_REF] Nouvel | Les entités nommées pour le traitement automatique des langues[END_REF]. A further step, geocoding, resides in disambiguating and adding geographical coordinates to a placename. Geocoding mostly relies on gazetteers, i.e. geospatial dictionaries of geographic names, mostly names, locations, and metadata such as typological information, variants or dates [START_REF] Hill | Core elements of digital gazetteers: placenames, categories, and footprints. Research and advanced technology for digital libraries[END_REF]. Toponym resolution as well as named-entity recognition can use machine learning methods [START_REF] Jochen | Detecting Geographical References in the Form of Place Names and Associated Spatial Natural Language[END_REF], however these are generally not ideal when tackling data not present in the training set, so that knowledge-based methods using additional fine-grained registers, for example from Wikidata [START_REF] Vrandečić | Wikidata: a Free Collaborative Knowledge Base[END_REF], have already been used with encouraging results.

Especially for historical corpora, researchers face a lack of general-purpose tooling. In order to produce cartographic visualizations, both the capacity to adapt to different contexts [START_REF] Alex | Adapting the Edinburgh geoparser for historical georeferencing[END_REF] and the necessity to complement existing resources with a precise historical gazetteer [START_REF] Borin | Geographic visualization of place names in Swedish literary texts[END_REF] have been highlighted. Such historical gazetteers exist, but their development is challenging [START_REF] Southall | On historical gazetteers[END_REF] even for texts as late as 20th century Europe [START_REF] Plini | One name one place? Dealing with toponyms in WWI[END_REF]. Existing toolboxes, such as AATOS [START_REF] Tamper | AATOSa Configurable Tool for Automatic Annotation[END_REF], mostly feature candidate extraction and ranking as well as entity linking. HeidelPlace [START_REF] Richter | Hei-delPlace: An Extensible Framework for Geoparsing[END_REF] does implement a comparable series of operations but it is currently tied to a series of engineering decisions which do not make its use on historical corpora straightforward. My approach is more light-weight, modular and adaptable, with a similar scope as CORE [START_REF] Mäkelä | CORE -a Contextual Reader Based on Linked Data[END_REF] but with an overall greater focus on usability, texts as input, integration of registers, and map export as images.

Tooling

Requirements

In order to process linguistically annotated text, it is useful to be able to start from either raw text or common formats for part-of speech tags and named entities recognition. The toolkit is pluggable to existing NLP solutions or usable directly on text, although morpho-syntactical analyses are appropriate in order to narrow down the search to relevant tokens, such as phrase heads found by surface parsing [START_REF] Barbaresi | A one-pass valency-oriented chunker for German[END_REF]. Gazetteers can be curated in a semi-supervised way to account for historical differences. Knowledge-based techniques are a way to tailor the geoparsing to historical contexts. Nevertheless, bootstrapping geographical data can save a significant amount of time. The generic gazetteer GeoNames [12] and structured data from Wikipedia and Wikidata are widely known to the research community. Wikipedia's API can be used to navigate in categories and to retrieve coordinates, including for historical places or areas. Current information is usually compiled from the GeoNames database, which also often includes historical variants. Additional lexical cues like stoplists or linguistic information such as suffixes or derivation ought to be configurable, as tools trained on modern texts do not necessarily tag historical morpho-syntactic patterns as needed. To provide support for manual annotation, an additional layer can be convenient as a geocoding bypass for targeted user lists which can operate on token or lemma level (using either linguistic processing or regular expressions and wildcards).

Concrete approach

The toolbox used for the experiments below is currently being developed [START_REF] Barbaresi | Towards a Toolbox to Map Historical Text Collections[END_REF] with historical texts in mind. It has already been used so far to map different text collections ranging from the 17th to the 20th century [START_REF] Barbaresi | A constellation and a rhizome: two studies on toponyms in literary texts[END_REF].

There is no commonly adopted standard for gazetteers, they have to be combined. Consequently, my approach allows for additional input, special sorting and prioritized merging, for example to put historical variants in the foreground. Second, it includes helpers to bootstrap geographical data, as knowledge-based methods using fine-grained data improve the results [START_REF] Vrandečić | Wikidata: a Free Collaborative Knowledge Base[END_REF]. So far, import filters for GeoNames and structured data from Wikipedia and Wikidata are implemented, with a particular emphasis on data cleaning. Third, an additional layer allows to bypass geocoding for targeted, easily extensible user lists which can operate on token or lemma level (using either linguistic processing or regular expressions and wildcards).

To spare resources, the extraction is performed by a sliding window capturing single tokens as well as multi-word expressions. Two different types of disambiguation methods [START_REF] Buscaldi | Approaches to disambiguating toponyms[END_REF] are included so far in the toolbox: map-based and knowledge-based. It has been shown that an acceptable precision can be reached by including meta-information [START_REF] Pouliquen | Geocoding multilingual texts: Recognition, disambiguation and visualisation[END_REF], which consists here in distance (based on a calculation relative to a contextual setting), type and importance of the entries (as known from information extracted from GeoNames or Wikipedia), as well as immediate context (e.g. the expected range and the last country seen). The process can be controlled by parameters set by the user, such as distance calculations, filter level or size of the search area.

Additionally, the toolbox integrates its own visualization component1 which makes use of the Python module matplotlib and its extension cartopy. It is profitable to allow for adaptability of projection and design and to leave it open to the user to refine the map, in a particular emphasis on the concept of visualization.

The toolkit is bundled as Python package, currently one of the most frequently used programming languages in academia, 2 it is available under an open-source license. 3 The release includes the code, especially the functions dedicated to geographic information retrieval, which form the bases of previous studies. It is meant to ensure replicability and extendability in an open science perspective and can hopefully respond to a growing demand in this field.

Contextual settings

The streamlined process from text to map involves a series of decisions as well as a critical reading of texts and maps. As user-definable settings make results vary, experiments can lead to diverging realizations. In fact, the extraction and visualization settings have a significant influence. In order to make them easily configurable, they are all accessible in a settings file. First and foremost, the filtering level affects both the construction of gazetteers prior to geoparsing and the toponym recognition phase in itself. Its purpose is to allow for a tighter or looser control on the data, with either restricted options or opportunistic search. Second, the minimum length of tokens to consider as valid toponyms, which is a function of the frequency, can be ignored or determined in advanced. Third, the disambiguation phase can be controlled by map-based parameters, notably the reference point for distance calculations and the countries in the vicinity, which help identifying the most probable candidates. Last, the cartographic processing in itself can be configured (window size and labels). Altogether, the settings allow for an opportune handling of historical texts. The process can adapt to different texts and contexts and it can evolve to reflect historical empires or regions for example, both during geoparsing (account for and disambiguate among historical names) and mapping (display historical or canonical names).

Risks and side effects 4.1 Examples

In order to better assess the impact of filtering and complementary registers, I present and discuss two different comparisons on close reading and on distant reading levels. Specially curated gazetteers are used, while current geographical information is used as a fallback, entries corresponding to European countries are retrieved and preprocessed. First, I test the coverage and the options at close level on a simple historical example. The sentence to be analyzed is from the late 19th century and features a series of proper nouns so that the experimental setting has an effect both on both form and content. 4 The standard fallback gazetteer, GeoNames, is known to be prone to coverage and data quality issues [START_REF] Ahlers | Assessment of the Accuracy of Geonames Gazetteer Data[END_REF]. Figure 1 displays an unfiltered view using raw text and GeoNames as only gazetteer. Only one point out of five is placed correctly while two other are wrongly considered to be placenames, and one place name is missing. The most prominent error concerns the token Berlin, which in GeoNames corresponds to a settlement in Northern Germany without inhabitants. The capital city of Germany is indeed never present as a single token in the dataset but systematically in the form of city quarters such as Berlin-Alexanderplatz. Figure 2 shows the impact of filtering (both knowledge-based and POS-based filtering lead here to the removal of false positives) and external resources (proper geocoding with a historical gazetteer). which lead to correct results when used in combination. This simple example illustrates how quality control and text analysis can benefit from the projection of the results on a map. Next, the impact of filtering methods on distant reading experiments is shown. Karl Kraus (1874-1936) founded his own journal, Die Fackel ("The Torch"), in 1899 and published it until his death. This complex and unique work resists summary description in its whole and in detail, it has been used as a basis for distant reading experiments using placenames and collocations as entry points to provide an additional, synthetic overview of the collection [START_REF] Barbaresi | Toponyms as Entry Points into a Digital Edition: Mapping Die Fackel[END_REF]. The present experiments use the same text base from the digital edition of the work [START_REF] Biber | Austrian Academy Corpus AAC-FACKEL[END_REF], the texts have been manually corrected as well as manually annotated with respect to the names of persons and institutions, so that most proper nouns which are not placenames can be excluded from the study. Figure 3 displays the results with a minimum filtering on a map showing most of continental Europe. Clusters can be found everywhere, not all of them being either intuitively explainable or justified with respect to the texts. In fact, the map tells more about the gazetteers used for geoparsing as about the work in itself. Current boundaries are retraceable, and numerous false positives come from plurilingual countries such as Switzerland or Belgium which are then overrepresented on the map. Figure 4 consists of a similar map featuring the results of maximum filtering level both during the construction of resources and during the extraction process. The map is more easily readable and depicts an accurate centering on Vienna and its surroundings. The overall Westward tropism of the mapped locations seems to coincide with the texts. This map is thus well-suited for further analyses.

Discussion

GeoNames, arguably the most commonly used gazetteer, has to be put under scrutiny, as the entries and their classification are subject to numerous problems, mostly unevenly distributed data and sparse metadata, which impact both detection and disambiguation of placenames [START_REF] Acheson | A quantitative analysis of global gazetteers: Patterns of coverage for common feature types[END_REF]. Nevertheless, this resource is still valuable mostly because of its coverage of language variants and thus potentially historical variants.

The status of placenames that are to be found and projected on the map also ought to be discussed. There are consubstantial ambiguities on linguistic level that complicate the search [START_REF] Smith | Bootstrapping toponym classifiers[END_REF]: the referent ambiguity (one name used for more than one location) and the referent class ambiguity (placenames used as organization or person names) are commonly addressed by disambiguation processes, whereas reference ambiguity (more than one name for the same location) has to be dealt with during the compilation of geographical databases. In general, successful detection and disambiguation relies on a smart interplay of resources and tools at different levels. Last, the case of either imprecise, vague or vernacular names [START_REF] Christopher | Modelling vague places with knowledge from the Web[END_REF] is a prominently linguistic issue which can at least be addressed by manual curation and should in any case be attended to.

Concerning the maps themselves, the consensus in the research community has evolved towards a relativity in construction and uses of maps, as there is neither a ground truth nor a cartographic truth. Although the maps seem immediately interpretable, they are not an objective outcome but a construct resulting from a series of interventions. "Selection, omission, simplification, classification, the creation of hierarchies, and 'symbolization' -are all inherently rhetorical" [START_REF] Brian | Deconstructing the map. Cartographica: The international journal for geographic information and geovisualization[END_REF]. As such, cartography is not the realization of static maps, but rather the description of emergent structures, and there is no single or best map.

Finally, the object of scientific inquiry does not simply reside in linking text to space, it is tightly linked to the interpretation of texts and maps. Even if the methodology conveys a feeling of scientific objectivity, the validity of mental and computerized operations described here should always be examined with respect to their relevance. Geospatial analysis and spatial representation may indeed be deficient or inadequate. The anthropological significance of toponyms has been emphasized by testimonies gathered on the field [START_REF] Feld | Waterfalls of song: An acoustemology of place resounding in Bosavi, Papua New Guinea[END_REF], but the symbolic role and the expressive power of placenames do not necessarily coincide with Western instrumental science and cartography, in that particular case the world geodetic system and the chosen map projection. This article introduced theoretical and practical instruments combining philological knowledge, geographic information retrieval and visualization, in order to streamline the steps needed to go from texts to maps. Examples of the issues raised by generic extraction have been discussed, they show the advantages of a methodology centered on historical texts and subsequent data cleaning and filtering. Being able to go through all the operation in one shot is ideal to assess the risks, to spot problems in methodology or datasets, and hopefully to mitigate the side effects.

The maps play an ambiguous role in distant reading, since they have to be flexible enough to adapt to new contexts and analyses, while remaining exact and in this regard trustworthy. The information they contain and reveal cannot always be verified on a point-per-point basis, yet it can be the starting ground of scientific reasoning. In fact, text visualizations are the substrate of interpretable representations which do not follow data but rather confront them by putting them in perspective. The difference between data wrangling and research in digital humanities resides precisely in the number and diversity of conceptual and technical filters which are repeatedly applied, consciously or sometimes unknowingly. The chosen approach and its inevitable imperfections have to be brought to light, documented and criticized.

In a linguistic perspective, the tools allow for the systematization of research as well as for a critical approach to the extraction and the very concept of placenames. As quantitative and qualitative analysis can go hand in hand, digital literary studies are not mere numeric accounts. They are first and foremost a discovery process. The use of filtering, the customized gazeteers and maps, in short the human interventions as well as the technical competence to do so recreate the hermeneutic circle of the philological tradition.

Figure 1 :Figure 2 :

 12 Figure 1: No filter, standard GeoNames setting Figure 2: Cleaned data with metainformation

Figure 3 :

 3 Figure 3: Minimum filtering Figure 4: Maximum filtering

The software used in previous experiments (TileMill) is no more under active development and needed to be installed and used separately.

https://spectrum.ieee.org/computing/software/the-2017-top-programming-languages

https://github.com/adbar/geokelone

Taken from Der Stechlin by Theodor Fontane: "Ich sage Ihnen, Hauptmann, das waren Preußens beste Tage, als da bei Potsdam herum die 'russische Kirche' und das 'russische Haus' gebaut wurden, und als es immer hin und her ging zwischen Berlin und Petersburg."


Adrien Fackel

Barbaresi

Toponyms as Entry Points into a Digital Edition: Mapping Die

come

Introduction

Proper nouns are a challenge for the apprehension of texts by machines. In information science and computational linguistics, out-of-vocabulary tokens (mostly common nouns absent from the dictionary, proper nouns, and foreign words) are delicate to deal with, especially in the case of historical corpora, since they require adjustments of indexing methods and fine-grained linguistic tools in order to be made queryable or visible. Nevertheless, one can assume that irregular, seldom seen words bear a particular significance and structure the texts in a peculiar fashion. Concerning toponyms, it is known from disciplines such as linguistics or anthropology that their relevance exceeds the frame of deictic and indexical functions, as they enfold more than a mere reference in space. His study on Bosavi language leads [START_REF] Feld | Waterfalls of song: An acoustemology of place resounding in Bosavi, Papua New Guinea[END_REF] to the idea that "place significance neither starts nor ends with the linguistic referentiality of placenames", and that "there is considerable variation in how names hold and unleash significance".

In the western tradition, a current of reflexion dating back to the 1960s has provided the theoretical foundations of the "spatial turn", whose epitome is the concept of space as emergent rather than existing a priori, and composed of relations rather than structures [START_REF] Warf | Introduction: the reinsertion of space into the social sciences and humanities[END_REF], as "our epoch is one in which space takes for us the form of relations among sites" [START_REF] Foucault | Of Other Spaces, Heterotopias[END_REF][START_REF] Foucault | Of Other Spaces, Heterotopias[END_REF]. As a consequence, both definition and importance of space have been re-evaluated throughout the humanities. The emergence of currents named "GeoHumanities" [START_REF] Dear | GeoHumanities: Art, History, Text at the Edge of Place[END_REF] or "Spatial Humanities" (Bodenhammer et al. 2010), has prompted for a transfer of research objects between disciplines as well as an enforcement of the spatial turn in practice through specific methods of analysis. Their common denominator consists in opening up new spaces and experimenting in a transdisciplinary perspective1 in a field which has been evolving at an exponential pace since the last decade [START_REF] Caquard | Narrative Cartography: From Mapping Stories to the Narrative of Maps and Mapping[END_REF].

Concerning the maps themselves, some of the most compelling examples reflect a relativity in their construction and uses of maps: post-representational cartography [START_REF] Rossetto | Theorizing Maps with Literature[END_REF], where there is neither a ground truth, nor a cartographic truth, and where "the map is not objectively 'above' or 'beyond' that which is represented" [START_REF] Crampton | Maps as social constructions: power, communication and visualization[END_REF]. Although the maps seem immediately interpretable, they are not an objective result but a construct, the result of a filtering, "a connection made visible" [START_REF] Moretti | Atlas of the European novel[END_REF]. Cartography is said to go beyond the realization of static maps, to the description of emergent structures. As such, there can be no single or best map.

Fulltext geocoding, also known as geoparsing or geographic information retrieval, describes the process of identifying place mentions in text and linking them to unambiguous spatial references; it typically involves three components: gazetteers, toponym detection and disambiguation. Methodological developments in this research area are tightly linked to progresses in mapping systems, mostly thanks to a technology-driven evolution [START_REF] Juvan | From Spatial Turn to GIS-Mapping of Literary Cultures[END_REF], as Geographic Information Systems (GIS) and corresponding series of tools mostly come from other disciplines. An underlying assumption resides in the belief that understanding language and literature is not accomplished by studying individual texts, but by aggregating and analyzing massive amounts of data: because it is impossible for individuals to catch sight of everything in a large corpus, advocates of distant reading employ computational techniques to mine the texts for significant patterns and then use statistical analysis to make statements about those patterns [START_REF] Wulfman | The Plot of the Plot: Graphs and Visualizations[END_REF].

The article is a developed version of a conference presentation at the Digital Humanities conference (Barbaresi 2017); it is structured as follows: first, the digital collection is introduced along with methodological considerations, then the processes used to extract and visualize place names are presented, finally three different realizations are shown and commented: a map of toponyms and two different views of toponymic cooccurrences.

Die Fackel (1899-1936)

Karl Kraus (1874Kraus ( -1936) ) founded his own journal, Die Fackel ("The Torch"), in 1899 and published it until his death. This complex and unique work resists summary description in its whole and in detail. Die Fackel includes few illustrations; it first resembled newspapers and increasingly became a magazine that was privileged in its editorial independence. Although it originally featured a few articles by intellectual figures, after December 1911 (Nr. 338) Kraus became its nearly exclusive author. Its field of interest embraced all major debates of its time, such as politics, culture, journalism, war, and overall the spiritual impoverishment of the intellectual society. Die Fackel denounced social masks and hypocrisy, most notably in politics and among journalists, and contained a series of attacks on corruption (in particular of the Habsburg Monarchy), and nationalism (notably the pan-German movement).

One of the hallmarks of Kraus' words is that they are not always to be taken to the letter. His extensive work on words not only supports criticism and satire by exploiting the full extent of different meanings but also by letting the readers reflect on the impact of a series of discourses, influences and powers [START_REF] Kouno | Die Performativität der Satire bei Karl Kraus[END_REF]. For example in the first issue, Kraus is critical of journalists who exchanged their free will or free spirit (Freisinn) against a flair for free theater coupons (Freikartensinn). These plays on words are often not directly translatable, an easier accessible example of modification on word-level is his characterization of the first world war as a "chlorious offensive" (chlorreiche Offensive, Nr. 443) which conveys altogether a feeling for the vanity of the war, the major role of chemical weaponry, and a certain linguistic accent.

Beyond his puns, Kraus' prose is known for its elaborate structures, complex syntax and the numerous allusions and citations, whose density increases in the journal's later issues. His typical and idiosyncratic style comes to expression through a great variety of different forms, such as essays, notes, commentaries, aphorisms, poems, and drama. His most characteristic satirical-literary technique is his montage and detournement of quotations, as he wittingly comments upon the quotes he finds in the press, in the literary works, and in the political speeches of his time.

On mapping historical text collections in general and Die Fackel in particular

In this paper, I present visualizations designed to analyze historical text collections in a spatial perspective. I wish to show that using place names and collocations as entry points can provide an additional, synthetic access to a digital edition of the work (AAC-Fackel) which is already available online.2 Although Die Fackel is particularly difficult to apprehend, in the digital edition the texts have been digitized, manually corrected as well as manually annotated with respect to the names of persons and institutions, so that most proper nouns which are not place names can be excluded from the study. I set out on a distant reading experiment leading to maps meant to uncover patterns and specificities which are not easily retraceable during close reading, in the sense that "mapping and visualisation concepts at the intersection of literary theory, cartography, and database technology could open up new dimensions of research." [START_REF] Piatti | A Literary Atlas of Europe-Analysing the Geography of Fiction with an Interactive Mapping and Visualisation System[END_REF]. The methodological implications of this interdisciplinary work are discussed and exemplified by "distant cartographic reading" on corpus level: "Thematic maps of spaces in literature visualize patterns that may tell the reader something important about the social content and impacts of literary forms; without these presumably 'non-theoretical' maps, such patterns would remain unnoticed and could not yield new theories." [START_REF] Juvan | From Spatial Turn to GIS-Mapping of Literary Cultures[END_REF] I focus on the concept of visualization, that is on the processes and not on the products [START_REF] Crampton | Maps as social constructions: power, communication and visualization[END_REF], and present them together with a critical apparatus, by giving a theoretical perspective on what is being shown and seen. In fact, digital methods in humanities ought to be criticized, especially since the cartographic enterprise bears both a thrill and a risk: "adding more to the world through abstraction", and "adding to the riskiness of cartographic politics by proliferating yet more renders of the world" [START_REF] Gerlach | Lines, contours and legends. Coordinates for vernacular mapping[END_REF]).

The plurinational nature of the Austro-Hungarian empire and the significance of Vienna as a cultural center at that time call for european-wide visualizations. In fact, Die Fackel is a European phenomenon with a decisively international extent, both with a thematic and a geographical focus. This work carries heterogeneity at its core and contains a considerable variety of toponyms [START_REF] Biber | In Wien, in Prag und infolgedessen in Berlin -Ortskonstellationen in der 'Fackel[END_REF] which are highly significant because of the multinational nature of the Austro-Hungarian empire and the later formation of a territorially diminished state. Regional and national peculiarities are explicitly referenced, through the names or through cultural or linguistic characteristics such as word choices, diction and accents. There are for instance a significant number of judiciary chronicles that were discussed in German-speaking newspapers at that time and consequently dissected by Kraus. There are close ties to events happening in Bohemia, the beginning of publication is co-existential with a prominent murder case in Czechia and Czech nationals are very often mentioned throughout the collection (Krolop 1994).

Place names can refer to people or events, they can also convey a particular function or message, like in the (very productive) construction of swear words, where three prominent types are found [START_REF] Welzig | Schmipfwörterbuch zu der von Karl Kraus herausgegebenen Zeitschrift "Die Fackel[END_REF]): substantive constructions with prepositional attributes: "Cherusci from Krems", "Teutons from Teplitz"; complex composita involving proper names, which may include modified components and are not analyzed here; and finally exemplary description of societal types and typology of discourses which are bound to nationality, socio-economic origins, confession, language, etc. Some toponyms are more easily extractable than others, the method described below does not apply to complex cases such as traditional denominations for parts of Vienna, which may be tricky to disambiguate even during close reading.

Mapping digital collections requires to describe the implications of making something visible, knowing that new visualizations are not always scientifically relevant or productive. Reading Die Fackel under the perspective of toponyms cannot end in maps which satisfy both literary and technical constraints. Maps are relative and subordinated to various purposes, the steps in making a map -selection, omission, simplification, classification, the creation of hierarchies, and 'symbolization' -are all inherently rhetorical [START_REF] Harley | Deconstructing the map[END_REF]. As long as this background is not eclipsed by the apparent perfection of numbers, I believe it is not only possible but also beneficial to find new accesses to historical text collections. The complexity of interpreting Die Fackel has been compared to a minefield, as mistakes are practically unavoidable, but at the time time it is precisely the ambitious apprehension of this difficult terrain that makes it possible to confront the texts in a philological way, in short to "light up the minefield" (Krolop 1994).

Extraction of toponyms

Among the tendencies in geographic information retrieval and geocoding [START_REF] Melo | Automated Geocoding of Textual Documents: A Survey of Current Approaches[END_REF], the extraction and normalization of named places, itineraries, or qualitative spatial relations, as well as the extraction of locative expressions are particularly relevant to study text collections. From the point of view of computational linguistics, toponyms are often out-of-vocabulary tokens. On lexical level, they are a potential error source for natural language processing tools, while on phrasal level, they are supposed to be identified by part-of-speech taggers as named entities (NE tag), or eventually by more fine-grained named entity recognition tools as place names. The processing chains usually stop at this point, they do not provide visualizations in the geographical sense, even if the toponyms can be linked to meta-information such as type and georeference.

In the field of information extraction, named entity recognition is a set of text mining techniques designed to discover named entities, connections and the types of relations between them. The particular task of finding place names in texts is commonly named place names extraction or toponym resolution. It involves the detection of words and phrases that may potentially be proper nouns as well as a second operation classifying them as geographic references [START_REF] Nouvel | Les entités nommées pour le traitement automatique des langues[END_REF]. A further step, geocoding, resides in disambiguating and adding geographical coordinates to a place name [START_REF] Leetaru | Fulltext geocoding versus spatial metadata for large text archives: Towards a geographically enriched Wikipedia[END_REF]. Toponym resolution often relies on named-entity recognition and artificial intelligence [START_REF] Leidner | Detecting Geographical References in the Form of Place Names and Associated Spatial Natural Language[END_REF]. However, knowledge-based methods using fine-grained data, for example from Wikipedia (Hu et al. 2014) or Wikidata (Vrandecic & Krötzsch 2014), have already been used with encouraging results. Combined approaches also lead to more complete or finer knowledge bases which are paramount in order to obtain fine-grained results.

Indeed, interdisciplinary work is paramount in order to produce cartographic visualizations of historical texts, as the necessity to adapt to different contexts [START_REF] Alex | Adapting the Edinburgh Geoparser for Historical Georeferencing[END_REF] and to complement existing resources with a precise historical gazetteer [START_REF] Borin | Geographic visualization of place names in Swedish literary texts[END_REF]) has been highlighted. However, corpus linguistics and geographical information systems have traditionally had very little to do with each other, although both approaches can benefit from each other [START_REF] Gregory | Visual GISting: Bringing together corpus linguistics and Geographical Information Systems[END_REF]. The present endeavor grounds on a specially curated gazetteer: during the 20th century there have been significant political changes in Central Europe that have severely affected toponyms, so that geographical databases lack coverage and detail. Consequently, the database developed at the Austrian Academy of Sciences (Academy Corpora) in cooperation with the Berlin-Brandenburg Academy of Sciences (Language Center) focuses on Europe and follows from a combination of approaches. Gazetteers are curated in a semi-supervised way to account for historical differences. Manual compilation and screening is sometimes necessary, because of the different names in the main languages of the area or because of changes in recent history, gathering existing information on the Web and completing it in the light of historical German and Austrian maps. Additionally, concurrent out-of-vocabulary tokens such as frequent proper and literary names are listed in order to exclude them from the study. Current geographical information is used as a fallback: Wikipedia's API3 is used to navigate in categories and to retrieve coordinates, which are completed by hand for states and regions; current information is also compiled from the Geonames database4 : data for European countries are retrieved and preprocessed (variants and place types).

The extraction is performed by a sliding window which captures single tokens as well as multiword expressions: the tokenized files of works to be analyzed are filtered and matched with the database by finite-state automatons. The recognition is refined through a series of contextual adaptations (Barbaresi 2017). As it is often necessary to assign the right coordinates to a toponym among several possible ones, disambiguation is a critical component [START_REF] Leetaru | Fulltext geocoding versus spatial metadata for large text archives: Towards a geographically enriched Wikipedia[END_REF]. It has been shown that an acceptable precision can be reached by applying a series of heuristics based on existing meta-information or various data generated on-the-fly [START_REF] Pouliquen | Geocoding multilingual texts: Recognition, disambiguation and visualisation[END_REF]. The use of a specially designed register as described above allows for bypassing the disambiguation for a handpicked list of places, which accounts for the specifities of the texts and the time. In the other cases, two different methods [START_REF] Buscaldi | Approaches to disambiguating toponyms[END_REF]) are used so far: map-based (geographically relevant contextual information) and knowledge-based (supplied external meta-information). The information taken into account consists in type and importance of the entries (as known from data extracted from Geonames or Wikipedia such as population counts) as well as immediate context (e.g. the expected range and the last countries and locations seen), which are controlled by predefined parameters, most notably customized distance calculations (here the distance to Vienna), filter level or size of the search radius.

Geographical and topical overview

In order to provide a typological overview of the digital collection, a cascade of filters is used: current and historical states (e.g. Austria-Hungary); regions, important subparts of states, and regional landscapes (e.g. Swabia); populated places; and geographical features (e.g. seas or valleys). The results are projected on a map of Europe which is static in nature, it features combined phenomena in a single image and provides an overview of toponyms in the collection. The use of a cartographical software (TileMill5 ) allows for the manipulation of mapping procedures, experimentation and fine-tuning of the visualization, whose main objective consists in making the overview interpretable and not obfuscated by the amount and diversity of information depicted. The assumption behind this mode of operation is the human eye is able to discern and filter patterns in a complex image [START_REF] Bertin | Sémiologie graphique : les diagrammes, les réseaux, les cartes[END_REF] if guided properly, especially concerning the distinction between various strata and the apprehension of color differences. To this end, the map in Figure 1 is customized with CartoCSS: multiple trial-and-error iterations are performed concerning both data quality and graphical output. The goal resides in finding the most relevant toponyms, which are depicted according to their frequency: only the most prominent ones are labeled, the size of the circles is proportional to the frequency. As expected, Central Europe plays a crucial role in the collection, the existence of numerous data points in Bohemia and Moravia confirms the importance of these regions. The relative importance of points placed in Northern Italy and along the Rhine spark questions about the method and/or their status in the work. They provide a ground for debate and are entry points inasmuch as they are an incentive to explore the digital edition in search for exhaustive evidence. What is more, the toponyms can also be seen as lexical entries to particular themes, especially in the high-frequency range for historical concepts ("Austria-Hungary", "German Empire"), which are placed arbitrarily on the map. In this perspective, mapping the work provides a topical index in a visual form. Since it is exported as an image for the sake of publication, the map can be considered to be static, it cannot be explored dynamically. However, this restriction can be addressed in part by adding a supplementary layer of visual grammar, this time not points but lines.

From collocations to lines of thought

In a further analysis, I visualize co-occurrences of all extracted toponyms, which can be considered to be a subset of GeoCollocations [START_REF] Bubenhofer | Geokollokationen -Diskurse zu Orten: Visuelle Korpusanalyse[END_REF], for which the basis has to be a toponym but without restriction on collocates. The two experimental maps below ground on the same data, they result from different settings. In the first case, only toponyms are considered and airborne lines are drawn following their order of appearance. The resulting sequences show which place names appear jointly in the texts.

Maps are mostly projected in Euclidean spaces where two points are connected by a single line. By extension, the word line defines a series of connected points on a plane, potentially both linkage and separation. Lines can enforce and divide, in the way that maps are instruments of power, another reason why the proponents of post-representational cartography call for a change of perspective. For example, lines that draw state boundaries are increasingly put into question, especially concerning historical states and texts, as they fix an evolving process and convey a sense of immobility that fails to describe the past accurately [START_REF] Smith | Networks, territories, and the cartography of ancient states[END_REF]). The word "network" is to be used with circumspection as [START_REF] Latour | On recalling ANT[END_REF] suggests. Although it is ubiquitous in the terminology of the spatial turn, the now predominant interpretation in the sense of the World Wide Web suggests an immediacy which is contrary to the acceptions it had before, so that the concept of "meshwork" is more appropriate [START_REF] Ingold | Lines: A Brief History[END_REF]. Thus, I interpret Figure 2 as a general meshwork which makes it possible to visualize paths depicting chains of thought (Gedankengänge) as well as their intensity (well-trodden or seldom). If they may reveal spatial patterns that would otherwise remain hidden in texts (Bodenhammer et al. 2010), these linkages are also "mappings and tracing imposed on the data" [START_REF] Wulfman | The Plot of the Plot: Graphs and Visualizations[END_REF] which are not meant to be interpreted without further filtering.

A rhizome as entry to Die Fackel

That is why I refine the map by selecting a subset of the co-occurrences -the maximal distance between two extracted place names is fixed to twenty tokens -and by color-coding qualitative features -the typology of place names (similar to Figure 1) and the axis of time. The most frequent place names are printed out. Surfaces (regions for instance) cannot be represented as such because of historical evolutions and because of the difficulties of linking surfaces without tampering with map readability. Coastlines are depicted in gray to give a sense of orientation, no boundaries are drawn, as they are of a changing nature and may superimpose an artificial reading of the map. In order to interpret Figure 3, I suggest to think about the implications of the concept of rhizome as formalized by [START_REF] Deleuze | Mille Plateaux[END_REF]. Its main principles are connection and heterogeneity, with no fixed order; "flat" multiplicity defined by "lines of flight"; "asignifying rupture"; and finally "cartography and decalcomania" ("tracing something that comes ready-made"). The rhizome puts an emphasis on several aspects of post-representational cartography as described above; it "pertains to a map that must be produced, constructed, [...] and has multiple entryways and exits" [START_REF] Deleuze | Mille Plateaux[END_REF][START_REF] Deleuze | Mille Plateaux[END_REF]). For there is no cartographic truth, the map has to be seen as a tool for the multiplication of accesses to reality.

The notion of rhizome has been used in corpus linguistics by [START_REF] Scharloth | Das Wuchern der Rhizome. Linguistische Diskursanalyse und Data-driven Turn[END_REF] to qualify discourses captured by collocation graphs: the authors performed significance tests to extract relevant collocations in the course of time, isolate clusters, and uncover lingering discourse elements. The notion of collocation and of subterranean word complex is a common ground, however the present study is different in its form and its content, because it literally leads to a map and most importantly because its text base is in itself rhizomatic. This concept is indeed particularly adequate for Kraus, as the Austrian satirist has always been concerned by the multiple aspects of discourse and reality. In addition, his work in Die Fackel evades distant reading processes because of the number of citations used and its ever present and extensive usage of parody. It would be vain to design an authoritative cartography of Die Fackel: following from the principles of heterogeneity and "asignifying rupture" (ibid.), the lines are frequently interrupted. Phenomena in the low-frequency range are filtered out by the human eye, but clusters and interpretation cues may emerge which provide a different access to the work. In this regard, Figure 3 depicts a rhizome connecting heterogeneous information, just as we are all "traversed by lines, geodesics, tropics, and zones marching to different beats and differing in nature" (ibid.).

Conclusion

I have presented a distant reading experiment which consists in connecting toponyms extracted and projected on maps. The latter are meant to be used as additional feature to the existing digital edition. 6 The first map provides a geographical and topical an overview of the collection, while further analyses introduce a sense of dynamism by targeting toponymic cooccurrences: the first example displays unfiltered lines of thought, whereas the second one grounds on a refined analysis and lets the practical image of a rhizome emerge. This is not an authoritative cartography of Die Fackel but rather an indirect depiction of the viewpoint of Kraus and his contemporaries. Drawing on Kraus' vitriolic recording of political life, toponyms in Die Fackel tell a story about the ongoing reconfiguration of Europe. As the map conveys the uncanny sensation that the continent is a field on which points east and west are projected, the lines of force entangle European countries and capitals. Their spatial patterns document an inclination for major cultural centers, whereas the chronological dimension captures a major shift towards the end of publication: the force field intensifies as its range narrows, showing both the interplay of major European powers of the time and the emergence of transatlantic (westwards) and transeuropean (eastwards) relationships. This evolution can be read as an intensification of tensions and a prefiguration of other schemes, this time of military nature. The notion of rhizome as exposed in this article is not only insightful in this case but also for the scientific process at work: the rhizomatic nature of text visualizations does justice to both philological and technological understandings and thematizes their essence as multiple, disrupted accesses to digital collections. Indexical maps are entry points both in the sense of an input which enters computational processes and in the hermeneutic sense, since they prompt for contextualizations and interpretations. In fact, digital literary studies are not mere numeric accounts. If on one hand they deal with detecting, counting, and projecting occurrences, on the other hand they have to include and criticize the distanciation provoked by "blind" computer-based thinking [START_REF] Barbaresi | La Raison aveugle ? L'époque cybernétique et ses dispositifs[END_REF]. Because the rhizome is in part a structuralist notion, it may be computed or even computerized. Thus it is only superficially paradoxical that blind numeric analyses can be applied in order to make linguistic phenomena visible. While Die Fackel criticizes mechanical, instrumental language [START_REF] Hirt | Improving Wikipedia-Based Place Name Disambiguation in Short Texts Using Structured Data from Dbpedia[END_REF], the "well-informed" linguistic instruments can help materializing dots or sequences. However, this is best performed under human supervision. As quantitative and qualitative analysis, both automatically generated outputs and hand-and-eye techniques, are indispensable [START_REF] Gregory | Visual GISting: Bringing together corpus linguistics and Geographical Information Systems[END_REF], the human interventions on the maps as well as the technical competence to do so recreate the hermeneutic circle of the philological tradition.

The finality of text visualizations is neither an apparatus nor a notion of an operational nature. It is instead the substrate of interpretable representations which do not follow data but rather interact with them by putting them in perspective. The difference between data wrangling and research in digital humanities resides precisely in the number and diversity of conceptual and technical filters which are repeatedly applied, consciously or sometimes unknowingly. The chosen approach and its inevitable imperfections has to be brought to light, documented and criticized. In this regard, spatial and digital humanities can hopefully be equipped with the adequate instruments and philological background in order to make computed information visible and apprehensible without adding more blind spots.

Figure 1 :

 1 Figure 1: Prominent place names on European scale (yellow: sovereign territories; orange: regions; green: populated places; blue: geographical features)

Figure 2 :

 2 Figure 2: Unfiltered map of toponymic co-occurrences

Figure 3 :

 3 Figure 3: Refined analysis (size proportional to corpus frequency; yellow: sovereign territories; orange: regions; green: populated places; blue: geographical features; time axis represented by a gradient from light green to dark blue)

"The parallel disciplinary structure of German-language Literaturwissenschaft and linguistics is not merely anecdotal; rather, it is an index of the necessary interchange of methodologies and content which holds beneficial possibilities for both fields."(Domínguez

2011)

http://aac.ac.at/fackel Free online access to

volumes, 415 issues, 922 numbers; more than 22.500 pages and 6 million wordforms.

https://www.wikidata.org

http://www.geonames.org

https://github.com/tilemill-project/tilemill

Software and gazetteer will be made available under open-source licenses, for development files see https://github.com/adbar/geokelone