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Computing Space 0: From Hypersurfaces to Algorithms: Saving Early Computer Cartography at the Library of Congress

Recently, the Geography and Map Division has undertaken a large scale project to collect manuscripts, technical information,  algorithms, software, and hardware from the earliest days of computer cartography. This project, which is being directed by the author, began as a series of lectures for graduate students that I gave at Johns Hopkins University on the mathematical foundations of Geographic Information Science (GIS), and which peaked my interest in early GIS many years ago. The program has resulted in the Library’s acquisition of a number of archives from the earliest days of computer cartography, produced by GIS pioneers like Nicholas Chrisman and Roger Tomlinson.

Magnetic Tape Containing an Early Version of SYMAP, one of the first computer cartography rograms developed at the Harvard Lab. Geography and Map Division, Library of Congress.

Magnetic Tape Containing an Early Version of SYMAP, one of the first computer cartography programs developed at the Harvard Lab. Geography and Map Division, Library of Congress.

These collections contain personal papers, notes, and technical publications related to the development of Geographical Information Systems, from some of the many imaginative geographers, mathematicians and computer scientists, working at places like the Harvard University Laboratory for Computer Graphics and Spatial Analysis, and at other centers around the world during the 1960s and 1970s, a time that saw the beginnings of what would become modern Geographic Information Science.

Holographic Map of the United States produced by Geoffrey Dutton at the Harvard Lab for Computer Graphics in 1978. This was a early example of four-dimensional dynamic cartography with the hologram rotating in space and changing with time. Photography by John Hessler

Holographic Map of the United States produced by Geoffrey Dutton at the Harvard Lab for Computer Graphics in 1978. This was a early example of four-dimensional dynamic cartography with the hologram rotating in space and changing with time.
Photograph by John Hessler.

The research at the Harvard Laboratory was a cross section of geographical ideas that were circulating at the time and these archives are a window into the mindset of early researchers active in a field that would revolutionize mapmaking. One series of publications which deserves much more attention from today’s  historians of cartography and anyone interested in the foundations of current geographic thought, are the Harvard Papers in Theoretical Geography. These papers, subtitled, “Geography and the properties of surfaces,” detail the Lab’s early experiments in the computer analysis of cartographic problems and also give insight into the theoretical thinking of many early researchers as they experimented with theorems from algebraic topology, complex spatial analysis, new algorithms and various forms of abstract logic in order to redefine the map as a mathematical tool for geographic analysis. Reading some of the titles in the series today, for example, Hypersurfaces and geodesic lines in four-dimensional Euclidean Space and The Sandwich Theorem: a basic one for geography, give one a sense of the wide range of experimentation and imaginative thinking that surrounded the breakthroughs necessary for the development of our modern computer mapping systems.

The Harvard Papers reveal, in a way that few other publications do, the multidisciplinary thinking that surrounded many of the lab’s projects. In an attempt to answer previously intractable geographical and cartographic questions, purely mathematical and geometrical concepts like existence theorems, whose basic logical structure contains statements that confirm or deny the existence of particular sets of objects, were employed in various computer mapping schemes. The development of these programs injected high levels of topological and algebraic abstraction into geographical analysis and fundamentally changed the basic ontology of geographic and cartographic objects. Existence theorems, although they provide logical proof for whatever mathematical entity they are claiming existence for, do not however, necessarily provide a way to find or calculate those objects.

Roger Tomlinson's Notes on the 1981 Harvard Computer Graphics Week Program. " Impossible to map the worls-we select-and make graphics of it so that we can understand it." Geography and Map Division, Library of Congress.

Roger Tomlinson’s Notes on the 1981 Harvard Computer Graphics Week Program. ” Impossible to map the world-we select-and make graphics of it so that we can understand it.” Geography and Map Division, Library of Congress.

The list of the authors of these papers, of which only fifty-seven were published, look to us now like a who’s who of the analytic turn that geography took in the post-World War II era. Names like William Warntz, Ernesto Lindgren, Michael Woldberg, Waldo Tobler, Donald Shepper, Carl Steinitz, William Bunge and Geoffery Dutton are just a few who added their insights and ideas to this highly theoretical series of papers.

Early Computer Map of the Crime Statistics of Washington,DC Early Computer Cartography Project, Geography and Map Division, Library of Congress

Early Computer Map of the Crime Statistics of Washington,DC
Early Computer Cartography Project, Geography and Map Division, Library of Congress.

Many of these researchers, and others, like Roger Tomlinson, who first coined the name GIS,  and Duane Marble, whose work broadened the theoretical foundations of GIS (his paper, written with Michael Dacey, from 1965, “Some Comments on Certain Technical Aspects of Geographic Information Systems, is must reading for anyone interested in this history) are responsible for the changes that we have seen in our current notion of what a map is. Today we are mapping more than just terrestrial and celestial land masses. Cartographers now regularly produce maps that move, employ big data, and focus on connection and flow as opposed to distance. Think of the maps of the internet, Facebook friends or Twitter. Current cartographers have increasing turned their attention to far from equilibrium phenomenon and are dealing with time as a fourth cartographic dimension. These changes have  come about because the early practitioners of computer cartography saw the deeper connections with mathematical analysis and topology and found themselves compelled to draw both distinctions and parallels with ideas that were appearing in the contemporary technical literature on spatial and temporal reasoning. Their explorations into this literature were not limited to geographical ideas on lived human space, but also drew on philosophy, cognitive science, pure mathematics, and fields like modal logic, all in order to somehow to come to terms with the diverse phenomenon that have spatio-temporal extent and that might be mapped and analyzed.

We can see this forward looking philosophy clearly in the work and thought of many of these early researchers. William Warntz for example, who was for a time the head of the Harvard Lab, wrote about the changing face of discipline,  in a way that, to me at least, still rings true,

“We now look upon maps not only as stores for spatially ordered information, but also as a means for the graphical solution of certain spatial problems for which the mathematics proves to be intractable, and to produce the necessary spatial transformations for hypothesis testing….The modern geographer conceives of spatial structures and spatial processes as applying not only to such things as landforms….but also to social, economic, and cultural phenomena portraying not only conventional densities but other things such as field quantity potentials, probabilities, refractions etc. Always these conceptual patterns may be regarded as overlying the surface of the real earth and the geometrical and topological characteristics of these patterns, as transformed mathematically or graphically, thus describe aspects of the geography of the real world.”

“We recognize yet another role for maps. In the solution of certain problems for which the mathematics, however elegantly stated, is intractable, graphical solutions are possible. This is especially true with regard to “existence theorems”. There are many cases in which the graphical solution to a spatial problem turns out to be a map in the full geographical sense of the term, “map.” Thus a map is a solution to the problem.”

Because of the deeper connections that modern cartography has across many disciplines like computer science, logic, and the philosophy of space and place, the Library of Congress is collecting quite broadly in the area of early computer cartography. It has obtained many other archives from cartographers like John Parr Snyder, who was the original developer of the Space Oblique Mercator Projection. It was Snyder who developed the equations for this extremely complicated projection using an early Texas Instruments programmable calculator.

John Snyder's TI-59 Calculator. Geography and Map Division, Library of Congress.

John Snyder’s TI-59 Calculator. Geography and Map Division, Library of Congress.

The equations for the projection allowed remote sensing imagery from the earliest Landsat satellites to be made into low error maps for the first time. In thinking through the geometry of the projection Snyder had to take into account the various motions of the satellite and the earth and in doing so invented a dynamic and time dependent map projection that was unlike anything cartographers had seen before. In addition to the technical material found in his collection, there are several notebooks into which he copied his ideas on map projections when he was sixteen years old, and that show him to be perhaps, one of the few modern cartographic prodigies.

Page from John Snyder's Projection notebook that dates from when he was 16 years old. Geography and Map Division, Library of Congress.

Page from John Snyder’s Projection notebook that dates from when he was 16 years old. Geography and Map Division, Library of Congress.

The study and science of cartography and its related geographical disciplines underwent profound technological and conceptual advancements in the last half of the twentieth century.  These advancements, brought about by the advent of computers, the development of newer and faster mathematical and computational algorithms, and the birth of satellite imagery contributed to paradigm changes that can be considered revolutionary. Technological and conceptual improvements have generated new forms of data, maps and artifacts that differ radically from those typically archived in map libraries. In the future these new artifacts and materials will form the basis for the study of the history of modern cartography and as such their collection and preservation present new challenges to the archivist and the map librarian. This rapid development in the mapmaking continues at a breakneck pace with no sign of slowing anytime soon.

The Library of Congress’ program of collecting computer software, new computational devices, hardware and new forms of geospatial data is based on the assumption that all of these need to be preserved in a way that allows future researchers to access not only historical geospatial data but also the techniques, data structures, and algorithms used by today’s mapmakers. Many of these ephemeral materials are disappearing, either through obsolescence, scholarly neglect, or the inevitable degradation of all magnetic media. These fragile parts of our history need to be collected now, before they disappear, for even though we are talking about materials from the recent past, the one thing we do not have in the preservation of this period of cartographic history, is the luxury of time.

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