Ancient World Mapping Center

Exploring the Forma Urbis Romae Fragments: A New Approach

E. Wolfram Thill, IUPUI

       The scope and complexity of the Great Marble Map of Rome make it an unparalleled resource, but also complicate attempts to work with its immense volume of fragmentary data. Originally covering an area of over 2,500 square feet, it depicted the architectural footprint of every ground floor room in the city, from the Colosseum cavea to the interior of sprawling apartment structures. It has been recovered in around 1,200 known fragments, some subsequently lost. Making sense of this data would be difficult in the best of circumstances, but the logistics of dealing with the sheer mass of marble involved has drastically limited access to the map. Imagine a puzzle where you have an estimated 10-15% of the picture, broken into 1,200 mostly non-contiguous pieces, each of which weighs dozens of pounds in cut marble.

Various technological revolutions have improved access to the map. Drawings on vellum of select fragments were superseded by expensive but comprehensive printed-plate volumes. The internet and three-dimensional scanning opened new possibilities for documentation and access. Now we are launching a new undertaking: the Great Marble Map of Rome Project. This project will use newly available technology to take the next steps in research on this unique and invaluable artifact.

The Great Marble Map, or Forma Urbis Romae, or Severan Marble Plan (more on that in a second), has always presented particular challenges for access, challenges that have shaped scholarship. Up to this point scholars’ primary interest in the map has been to piece it together, and to identify and connect depicted buildings with structures known from the historical or archaeological records. These approaches tend to engage with the monument at the level of the fragment or individual depiction. To some extent this is a product of access, since it has been difficult to study more than a few fragments at a time. While topographic inquiries are certainly worthy pursuits, scholars have pointed out that such approaches downplay the original display context of the map. The majority of the depicted buildings are generic, unidentifiable structures that would have been difficult even to see, given that the original dimensions of the map were a staggering 18 x 13 meters, or around 60 x 43 feet.

The newest approaches to the Great Marble Map move beyond focus on individual buildings, to look at what can be learned from the plan as a whole. Such approaches require better access to both the fragments and their original context. It is here that the Great Marble Map of Rome Project has taken up the torch. The project is sponsored by the Ancient World Mapping Center at the University of North Carolina, Chapel Hill, in partnership with the Musei Capitolini and Sovrintendenza Capitolina ai Beni Culturali in Rome. The mission of our project is to use new technology to achieve several goals. These are:

1)      To give wide and comprehensive virtual access to all aspects of the map

2)      To advance scholarship on the map and to take it in new directions

3)      To encourage public engagement with the Great Marble Map, particularly with regards to the actual fragments in Rome

Our primary means of achieving these goals will be a new website and online database that makes available three-dimensional scans of all 1,200 fragments and their original context.

Our first, inaugural enterprise for the project has been a photogrammetric scan of the wall on which the Great Marble Map was once mounted. The wall that now forms the north exterior face of the Basilica dei Santi Cosma e Damiano was originally an interior wall of a room within the Temple of Peace. Although the majority of the marble was robbed in the Middle Ages, pieces were excavated at the foot of the wall, confirming its association with the monument. The wall was divided into two zones, an upper section on which the map was mounted, and a tall socle below. The 150 or so marble slabs that once made up the map were fastened to the brick wall with metal clamps. The holes for many of these clamps are still preserved in the wall, despite modern interventions such as the insertion of windows. Since many marble fragments also preserve corresponding clamp marks on their back face, it should be possible, in theory, to align the clamp marks on the fragments with the clamp marks on the wall, reconstructing the original position and alignments of fragments. Previous attempts to do so, however, have been uncertain and slow, since they relied on working with the actual fragments and scale drawings of the wall. Three-dimensional models of all the fragments, however, were produced around 2002 by the Stanford Digital Forma Urbis Romae Project. What was needed was a corresponding model of the wall.

Our project’s solution has been to make a three-dimensional scan of the wall itself using Fan Photogrammetry. Generally speaking, this type of photogrammetry works much like a stereoscope. The process produces a series of overlapping but offset images that, viewed through the appropriate two-toned glasses, create a three-dimensional effect. Modern camera techniques and capabilities mean that this can be accomplished at an amazing level of detail over large areas and from considerable distances.

Mission Wall Scan was launched in May 2019, when a team traveled to Rome to take the necessary photographs for building the three-dimensional images of the wall. The research division of our team consisted of Dr. Richard Talbert of the Ancient World Mapping Center, Dr. Francesca De Caprariis of the Musei Capitolini, and myself from IUPUI. We were joined by a technical team from Queen’s University, Ontario led by Dr. George Bevan, assisted by Kristen Jones and Dr. Daryn Lehoux.

I am indebted for all technical descriptions of this process to Kristen Jones, who kindly provided more specific understanding than my “and then we took pictures of the wall.” The Queen’s University team employed a fan photogrammetry technique, shooting at seven Gigapan stations with their camera mounted to a fence along the sidewalk of the Via dei Fori Imperiali, approximately 50 meters away from the face of the wall. Scale was achieved using custom-coded scale bars, two in a right angle L configuration, and two more in windows across the wall. This allowed the team to imitate aerial-photographic mapping techniques. The Queen’s team shot 30 images at each of the seven stations using a telephoto lens with a 1.5 mm ground pixel size. To deal with the variable weather, Dr. Bevan and his team shot four sets of photographs over three days. This method allowed them to capture the part of the wall where the map was mounted. In order to capture the socle zone, primarily for conservation purposes, Dr. Bevan photographed the area by hand from a distance of 5 meters, shooting straight on for one set of photos and then upwards at a 45 degree angle to link the images with the larger dataset of the whole wall.

Our initial product is a three-dimensional record of the wall that once held the Great Marble Map. It is so precise that, despite being shot from 50 meters away, you can zoom in and see the textures of individual bricks. With the appropriate glasses, the effect is surreally three-dimensional. Given the right software, you can measure the space between holes and even the depths of the holes themselves within 1 mm of accuracy. In addition, Kristen Jones was able to use the merged high-resolution orthophoto to trace individual features of the wall using 3DM analyst and AutoCAD. Her end production is a series of precisely scaled drawings that highlight the clamp marks on the wall.

The next step will be to make these images of the wall available online as part of our new website. In the final presentation researchers will be able to directly compare the three-dimensional models of the fragments with the clamp marks on the wall scan. This should not only facilitate reconstruction and new joins among fragments, but will allow researchers to gain a clearer understanding of the physical setting of the Great Marble Map. What sort of distance, for example, separated various depicted structures? Are the sizes of inscriptions related to position on the wall? How is the work of different carvers distributed throughout the map and along the wall, and what does this suggest about the logistics of carving? These are just some of the questions we hope our new presentation can encourage and investigate.

The second initiative undertaken as part of our project is to further facilitate research on the Great Marble Map fragments. Because access to the fragments has been limited to a close circle of specialists mostly working with identifiable depictions, basic issues such as nomenclature and referencing systems have never been fully addressed. For example, there is no standardized system for referring to features represented on a given fragment. While this is not a problem when referencing structures such as the Colosseum, it becomes problematic when wanting to refer to, say, individual rooms around an unidentified peristyle. This will become more of an issue as scholars increasingly ask research questions that depend on generic, unidentified structures.

Even the name of the monument itself needed updating. Without going into too much detail here, we rejected anything pseudo-Latin, overly technical, or otherwise unintelligible to a broader public. Instead we decided to stick with the basics: the Great Marble Map of Rome. I therefore used this name for this presentation, in the belief that if you say it enough, you can induce others to use it too.

We are still working on a system for numbering the individual fragments and features, but as I will show, modern technology can make the presentation of a system much simpler. New software makes it easy to color-code and annotate three-dimensional models, rendering them more understandable for map experts, researchers new to the map, and the interested public. I am indebted here to my colleagues Jenny Johnson and especially Derek Miller at IUPUI Library’s Center for Digital Scholarship. With Derek’s help I was able to paint a pilot model using Mudbrick and to display the finished project via Sketchfab, without either process actually changing the underlying data. The original model shown here was produced as part of the Stanford Digital Forma Urbis Romae Project and is under the copyright of the Sovrintendenza. All models are to carry the Sovrintendenza’s watermark, but I am not yet sufficiently skilled to embed it (or to demonstrate familiarity with other tools).

What you see here is a section of the map currently known as 3ab. This section was drawn in the Renaissance as one large piece in a sketch now preserved in a Vatican Codex. Sometime later part of it was lost and replaced by a cast. Here is the newly painted model. I have marked inscriptions in red, commercial structures in yellow, columns in green, and arcades in blue. Crucially you can still manipulate the model, spinning it to check possible joins and clamp marks (this one doesn’t actually have clamp marks, so was a poor choice for my pilot model perhaps). One methodological problem that can arise when working with the Great Marble Map is that it is often not obvious to non-specialists what is actually extant. The next view of the model has the cast part dimmed to highlight the distinction between what is marble and original and what is not. This third view goes further, removing all markings from the cast to really emphasize what is actually preserved.

Sketchfab also opens up great potential for annotating models. Previously one of the challenges in creating a numbering system was a basic inability to display any such system in a legible form. Sketchfab can make presenting a numbering system less cumbersome. In this mock-up, I have added reference numbers to each feature. Feature 3.1 is an inscription, 3.2 the street, 3.3 the colonnaded courtyard, and 3.8 a commercial room. Crucially, you can toggle the annotations off and on as needed.

Another potential for annotation is to open the audience for the models. In the version shown here, I have annotated the model for the Roman specialist. The cast has the full reference number for the codex drawing, and the inscription has its official epigraphic transcription. In the next version, I have modified the annotations for the interested non-specialist, say an amateur historian. The cast annotation explains the history of the fragment, and the inscription annotation explains the transcription. My favorite possibility, however, is that the model can be annotated in order to develop curricula for students of various ages. In this version I have written the annotations for a grade-school audience. The cast annotation spells out the history more plainly, and the inscription annotation teaches vocabulary such as the term “inscription.”

We hope these new forms of presentation will help to uncover not only new physical, but also conceptual, links across fragments. In terms of physical joins, by clarifying what each puzzle piece represents, the color coding should make it simpler to see what we are searching for in a match. In this case, for example, we are looking for a commercial peristyle building along this edge, or more simply, a yellow and green building above a red inscription. In a more theoretical vein, this presentation holds great potential for researching into the representations of architecture. How are domus represented? What features of temples are emphasized? What can the depictions of public leisure parks tell us about how such spaces were conceptualized?

The most exciting aspect of the website, however, is that its ultimate goal is to facilitate work with the extant fragments themselves. Previously this would have been a vain hope, since the map fragments were inaccessible in storage. But there is a new, as yet unnamed, museum being prepared in Rome as part of the Musei Capitolini. The brainchild of Dr. Francesca De Caprariis, this museum will house all the map fragments in the Sovrintendenza’s care. Indeed, our team was privileged to see all of them in their new home during our work in May. Many fragments will be on display in a permanent exhibit dedicated to the Great Marble Map. The other fragments will be easily accessible for visiting researchers.

The location of the new museum has great potential to engage a wide public audience. Located in a former gymnasium for Mussolini’s Fascist Youth, the museum is within sight of the upper tiers of the Colosseum. An attached garden will house an epigraphy museum showcasing numerous architectural membra that were deposited there in the large-scale excavations of the late 19^th and early 20^th centuries. And a service building will eventually house the most important features of Roman culture, a gelateria and caffè.

The website will thus serve as an international gateway for the new museum. Scholars can develop hypotheses online, and then test them against the actual fragments in Rome. Study abroad groups planning to visit Rome can start a curriculum about the Great Marble Map in the classroom, and then continue it in the new museum and on the streets of Rome. For example, a student could prepare a presentation on the Colosseum fragments in the classroom, deliver it in the museum utilizing the actual fragments, and then continue the presentation at the Colosseum itself.

All of this is early days for our project. But our goals are in progress and achievable. We want to use new technology to make the Great Marble Map more accessible. We want to advance research and take it in new directions. And we want to achieve a wider audience beyond academia.

Less specifically as yet, we dream of making new scans of all the fragments, in particular to improve the underlying models and to speed their painting and annotation. Although at the cutting edge at the time, the Stanford scans reproduce only the basic outline of a fragment. They are also in a fossilized .ply format, meaning they must be individually converted to a more accessible .obj format and UV wrapped, a time-consuming and error-prone process. New laser scanning can quickly produce a paintable model that captures color and texture, as well as more precise contours.

In terms of public engagement, we want to develop an extended set of curricula that will allow students of all grades to engage with the Marble Map online, with the ultimate culmination being a visit to the museum in Rome. We want to develop an app that would allow tourists to take the Marble Map out with them into the streets of Rome and juxtapose it against the ancient monuments. We want to develop a virtual reality experience that would allow a viewer to walk around the reconstructed walls of buildings represented on the Marble Map. We want to maintain a database that is continually updated to represent advances in the field. We want to have a crowd-sourcing feature, where interested participants can work to find joins between fragments.

Not all of these dreams will be immediately attainable. But we are already bringing undergraduate students into our project through an IUPUI Digital Scholarship Fund. Graduate students in the Ancient World Mapping Center, as well as UNC’s School of Information Science, are ready to contribute too. We have the drive, we have the ideas, and we have a plan.

What Difference Has Digitization Made ?

Tom Elliott, New York University

It’s customary in talks about the digital classics to start the era with David Packard’s concordance to Livy, published in four printed volumes in 1968. This work — although deliberately unoriginal in its conception and delivery mechanism — nonetheless demonstrated conclusively that computational methods were both ready and appropriate even then to apply to philological research and reference work.

Packard’s Livy started after, but appeared before, another watershed achievement in philological computing: Roberto Busa‘s monumental Index Thomisticus. First conceptualized in the 1940s, and supported for years by IBM, this comprehensive lemmatization and concordance of the complete works of Thomas Aquinas was prepared using punch cards and published in 56 print volumes in the 1970s. A web-based version was published in 2005 and work continues to build on its foundations, employing treebanking and other modern methods of natural language processing.

       Classics has struggled over the subsequent half century to embrace computing in a way that evenly recognizes its practitioners as equal partners in scholarly endeavor. But despite this difficulty, there can be no denying that computing has changed the field irrevocably. Indeed, Marianne McDonald’s proposal for “the creation of a computerized databank of Greek Literature” closely followed Packard’s concordance in 1971, eventually bringing forth the earth-shaking Thesaurus Linguae Graecae (a project in which Packard and McDonald both played significant roles). The TLG is a uniquely pivotal work, resetting both expectations and methods field-wide, even though its full potential has been blocked by the aggressive enforcement of its restrictive license.

       But other flowers — increasingly varied in both beauty and function — have spread more freely across the intellectual landscape, products of both radical experimentation and patient gardening. Digital publications and research tools in epigraphy, numismatics, papyrology, philology, history, archaeology, and geography have proliferated (for a sampling, see the Digital Classicist Wiki and its list of Projects. And new ones — and new ways of using them — continue to emerge. The program for our present meeting illustrates this fact. Some naive word-searching turns up 35 unique abstracts that include terms like “digital,” “computer,” and “on line.” I’ll assert that the number of papers that depend on computation for data collection, record management and analysis is even higher, though the use of same has become so ubiquitous as not to merit mention in many an abstract.

       But if you want to come to close quarters with where classics has got to by way of digital methods in philology, and the places it might go from there, you must make plans to attend this afternoon’s session on “reconnecting the classics,” organized by the Digital Classics Association. The session features eight important voices in the digital classics, considering everything from the latest tools in computational philology to the challenges and opportunities presented by current crises in the undergraduate curriculum and classics praxis.

       Another session worthy of your attention has been organized by the Publications and Research Committee and scheduled for Sunday morning. It focuses on the Digital Latin Library, a joint initiative of the SCS, the Medieval Academy of America, and the Renaissance Society of America, that has been funded by the Andrew W. Mellon Foundation. The five papers in this session will highlight the ways in which the DLL blends traditional Latin philology with new approaches from the field of digital humanities.

       Early digital philology and its progeny constitute but one of the paths that leads to digital geography in the classics. For a fuller picture, we have to reach back earlier, to the antecedents of computing itself. Ada Lovelace‘s 1843 diagram for the computation of Bernoulli numbers is considered by many to be the first published algorithm intended to run on a computer. The computer in question was the so-called analytical engine envisioned by Charles Babbage, Lovelace, and their collaborators. Although the machine was never built, and so Lovelace’s algorithm was never implemented, it is one of the earliest antecedents of everything that happens today on your phone, tablet, laptop, or other device that includes a microprocessor.

       It then took a hundred years or so, but by the mid 20th century, an explosion of computing innovation was imminent. The explosive had been compounded of such volatile ingredients as the enlightenment science that Babbage, Lovelace, and their contemporaries inherited; and the wealth imbalances, state actors, and corporate powers that had emerged from colonialism, the Atlantic slave trade, the new imperialism, capitalism, and industrialization. To these were added other ingredients like the mechanized armies and industries that had been spawned by World War II and subsequently turned their attention and resources to a global Cold War of unprecedented technological complexity.

       Mathematicians like Dorothy Vaughan, Grace Hopper, and Margaret Hamilton were writing the first machine-language programs to calculate rocket and artillery trajectories; developing the first symbolic programming languages that would make software more versatile and maintainable; and coding the software that made it possible — 50 years ago this July — for Neil Armstrong and Buzz Aldrin to land on the moon and return safely to earth, thereby demonstrating (among other things) that the US had the technological and industrial capacity to deliver nuclear warheads anywhere on the earth with speed and precision. It was the space age, and the information age was swelling in its head, ready to leap forth into the fields of war and commerce.

       And into mapping for the classics, as it turns out.

       Let’s chart our return to the subject of this panel by way of our sibling discipline: geography. More specifically, let’s consider the gift that our metaphorical information-age Athena has bestowed upon that field, namely: Geographic Information Systems. The story starts in 1962 with Roger Tomlinson and the Canada Land Inventory. This project, overseen first by Canada’s Department of Forestry and Rural Development, and later by the Department of Energy, Mines and Resources, compiled maps and other information indicating the capability of land to sustain agriculture, forestry, recreation and wildlife. Given the way I’ve characterized the development of the information age, you’re probably not surprised that I’d identify the modern nation state as the primary actor in GIS and that its focus would be land management and inventory of exploitable resources. This theme dominates the early decades of GIS and remote sensing, which saw the introduction of a series of open-source and commercial software packages built to serve the interests of the nation state and of private commerce. Key domains of interest included not only land use and natural resource management, but also census, navigation, military planning, utilities and infrastructure, emergency response, and city and regional planning. The passage of the Archaeological and Historic Preservation Act of 1974 in the US added cultural resource management and archaeological impact assessment to the GIS menu, quickening its adoption as a standard tool in archaeological work.

       I’ve included on the slide you see the infamous “GIS Layer Cake” illustration. It will be familiar to those of you who have had occasion to learn GIS in a formal environment or to consult standard textbooks or help documentation. The illustration is here to help me point out one of the key legacies that GIS received from conventional cartography: the idea of layers. Richard Talbert has already mentioned the process whereby maps were composed photographically from layers of film. Most of these layers were thematic, dividing the map’s content into manageable groupings that required common visual treatments such as shaded relief, elevation tint, drainage line work, cultural symbology, labeling, and so on. Thematic layers made for intuitive data structures and associated interaction artifacts on-screen, and so they made their way into GIS. But GIS transcends its cartographic forebears in part by putting these layers to work for more than cartographic representation. The constitution of a map — its bounds, extent, projection, final scale, color scheme, labeling — can be deferred, revised, and iterated upon throughout a production or analysis project. Layers can be created by computation against the content of other layers and used solely as a data source or interstitial calculation result that never itself appears in the final map.

       But a final map is often not really the goal anymore. Most of the features provided by GI systems and most of the time spent working with them involves geospatial information management and spatial analysis, not cartographic production. That is, GIS is used to test hypotheses and answer research questions that are geographic in nature. Maps are incidental to the process: data visualizations well suited to human supervision of the analysis and illustration of its results. To be sure, the rhetorical power of an authoritative map remains strong when the goal is to convince others to adopt a course of action or accept an argument, but we should think of GIS as much more than a tool for map-making. Many other tasks that, in an earlier age, would have preceded map production – or that would have occurred afterwards in one or another use context – have been bundled up with the strictly cartographic functionality into a single software environment augmented with additional capabilities and complexities that would have been beyond the reach of pre-computational geographers.

What are we doing with all this? Geographic information systems have put unprecedented analytical capabilities in the hands of classicists. Geospatial information structures and their attendant computational methods let us analyze visibility of features in a landscape, interrogate cost surfaces to estimate travel times, construct networks of places mentioned in literary works, calculate Thiessen polygons to approximate the extents of linguistic or administrative regions, and more.

       We can also use GIS to create spatial datasets for use by others. Among the many achievements of the Ancient World Mapping Center in the 18 years since its founding is the creation of spatial datasets suitable for a variety of analytic and cartographic purposes. These datasets are being used by others not only because of their uniqueness and quality, but also because they are distributed free of charge under open license. We may get to hear a bit more about this shortly in Lindsay Holman’s paper.

       I would be remiss if I did not mention, in this of all sessions, that the AWMC owes this heritage of successful open-access publishing to the Society for Classical Studies. For, although we identified openness as a core value for the new Center, it was the SCS that granted permission for the reuse of the Classical Atlas Project’s compilation materials without charge for the benefit of the field.

       And so the SCS helped bring to life another of the AWMC’s data publications: the Pleiades gazetteer of ancient places. I think that Lindsay will probably speak about Pleiades as well, but I hope she’ll forgive me if I say a few words about its design and about the current state of geospatial data work in ancient studies, which depends heavily on gazetteers like Pleiades. For a gazetteer is a thing that any mapmaker wants, whether working in analog or digital media.

       What is a gazetteer? Basically, it’s a geographic reference work: a big bucket full of reasonably consistent information about places. In traditional print, a gazetteer takes the form of a list of placenames, together with their known variants, associated spatial coordinates, and other distinctive attributes such as feature type (for example, city, temple, or forest). They have sometimes contained additional information, or even longer descriptive or historical narrative, blurring the lines with things we sometimes call almanacs or geographic dictionaries. At the simple end of the spectrum, they can serve as indexes into a map or group of maps. Such a bare-bones gazetteer appears at the back of the Barrington Atlas.

       The notion of a digital gazetteer solidified in the information science community of the 1980s and 90s. As the idea of digital libraries began to take shape, gazetteers were re-conceived as controlled vocabularies of placenames that could be used to facilitate activities such as automatic document linking, geoparsing of texts for named place references, and for regularization during data entry. The geospatial data included in digital gazetteers could be used to enable spatially aware search functions and to map arbitrary collections of content produced, for example, by a search engine. Influential pioneers in this area included Linda Hill and Ruth Mostern for the Alexandria Digital Library project at UC Santa Barbara, and David Smith and Greg Crane for the Perseus Digital Library project at Tufts University. Crucially, the complex spatial analysis and cartographic visualization capabilities of GI systems were not seen as components of a digital gazetteer. One might use GIS in the development and maintenance of a gazetteer. One might also load the contents of a gazetteer into one or more layers in a GIS to combine with other data for map-making or analysis. But the gazetteer itself was thought of as a database or dataset, together with a few computational services meant to support its use in another digital system.

       In deciding to take the Atlas Project’s information digital and on-line, we eventually concluded that this idea of a digital gazetteer better fit our data and our mental model than a GIS.

       One particular constraint of most GI systems was inimical to our data: the expectation that every feature of interest should have a well-defined spatial geometry (a point, line, or polygon). The limits of horizontal accuracy and the numerical precision of spatial coordinates can be codified in GIS (usually at the layer level), and even topological relationships with other features can be modeled, but features whose locations are wildly uncertain must nevertheless be represented with bounding boxes or representative points if they are to make an appearance in the GIS at all. The compilers and editors of the Classical Atlas Project reflected both the ancient sources and modern scholarship in giving us tons of such places. In the Barrington Atlas you’ll find them grouped in special sections labeled “Unlocated” in the Map-by-Map Directory volumes.

       Further considerations multiplied quickly. Many types and degrees of uncertainty obtained in our data. To take one example: how confident are we that a toponym appearing in an ancient witness is to be associated with a particular archaeological site or presumed locality? Richard and I enumerated such concerns in a paper that first appeared in 2002. It has now been reprinted in Richard’s “Challenges” book.

       We also envisioned a body of spatial information that might be under periodic revision at the individual place level. New archaeology, new texts, new analyses might all necessitate updates or corrections. Volunteer fieldwork with hand-held Global Positioning System receivers might contribute coordinates with more precision than the limited scale of the atlas maps had provided. New work with better satellite imagery might someday do the same. In this regard, our information-age Athena played more tricks on us. The chief agent of disruption this time was Google, whose relentless pursuit of on-line ad revenue led them to invest in the spatial aspects of digitally mediated commerce, giving away masses of map data and aerial and satellite imagery together with information about the locations of commercial entities and the way-finding services necessary to reach them. We’ve all paid for this apparent largesse, of course, by submitting our related behaviors to Google’s scrutiny, analysis, and monetization schemes. Another, less creepy, source of surprise was the OpenStreetMap community, which has dedicated itself to producing a user-created map of the world whose content is free and open by design. It has made a lot of progress, and Pleiades relies increasingly on their work.

       The gazetteer model has proved flexible enough to accommodate all these eventualities and more. Our commitment to openness complemented this flexibility by freeing us from the responsibility to reinvent and maintain GIS functionality on line for our users. If you want to do spatial analysis that involves Pleiades data, download the data and pull it into your GIS of choice. That’s what it’s there for.

       Identification as an open digital gazetteer also positioned Pleiades to play a leading role in reconfiguring the notion of digital gazetteers themselves. Pleiades serves not just one particular, curated digital library, but instead multiple arbitrary tools and publications distributed across the world-wide web and maintained by a variety of third parties. Providing the catalyst this time was Tim Berners-Lee, the inventor of the web, whose thoughts on stable identifiers and Linked Data influenced us significantly. I’ve spoken recently about Linked Open Data, scholarly digital publication, and the value of the computationally actionable citation that results. The text of that talk is on my website, so I won’t go into much detail here. Suffice it to say that scores of digital scholarly publications around the world are aligning the geographic aspects of their content to a growing number of general and specialized digital gazetteers that are also aligning themselves to each other. As a result, the probability is growing that the data a classical scholar assembles to begin or augment a particular study will already be collated along geographic lines. You won’t have to sort out whether the inscriptions cataloged in one dataset you downloaded are from the same Alexandria as those in another dataset. Both datasets will cite a relevant gazetteer entry, leaving the ambiguity of textual reference behind. This method is already expanding beyond geography to other facets of relevance like prosopographical identity, named time periods, calendrical dates, and cross-language technical terminology.

       If I’ve timed my talk right, I should be coming to the end of my 20 minutes. I’ll conclude with one more advertisement for another session. If you’d like to learn more about the difference that digital practice is making in classics scholarship, then on Sunday morning you should attend the session on “geospatial classics” organized by two other Mapping Center veterans: Gabriel Moss and Ryan Horne. Papers in this session will explore specific applications of geospatial techniques to the research and pedagogical challenges of the Classics. Every person presenting in this session is an innovative and thoughtful scholar whose paper should not be missed.