What is a Processual Approach to Mapping?

Matthew Edney

I have in hand a post about the concept of the “thematic map” that addresses why the distinction between thematic and reference/general maps is thoroughly misleading. But before I can complete that post, I need to give some account of what I mean by a “processual approach.” This is a huge and multifaceted topic—indeed, it’s what this entire blog is about and I plan to write an entire book on the subject—but here’s a preliminary statement to start off with.

more than one kind of mapping

Consider map scale, which is generally treated as a continuum from the ideally perfect map at 1:1 to the maps that greatly reduce the world:

[Remember that the relative categories of scale are defined by the number to which the numerical ratios resolve: 1:1 resolves to a number, 1, that is larger than that to which 1:10,000,000 resolves, i.e., 0.0000001, so 1:1 is said to be larger in scale and 1:10,000,000 to be smaller in scale.]

I thoroughly distrust continua. Any time someone presents you with a continuum, run away. Fast. Don’t even wait to count to three; just run away. Perhaps the only other kind of intellectual construct I distrust more than a continuum is a classification that includes a final, “miscellaneous” category.

Why? Because continua hide what’s really going on. They take description and present it as explanation, but they don’t actually explain anything. Continua are constructed when the form of some phenomenon varies widely and without clear boundaries, and when the underlying processes that actually give form to the phenomenon are not known or ignored.

In the case of the continuum of map scale—which is referenced every time a map is described as being large scale or small scale, or something inbetween—maps are arrayed by the degree to which they apparently simplify or reduce the world in depicting it on paper (or on a digital screen). There seems to be a continual and smooth transition from one end of the continuum to the smallest map.

In seeking to integrate cadastral mapping databases with natural resource mapping for land management purposes, Dick Dahlberg (1984, 149–50) revealed a “gap” in the kinds of maps available, between cadastral maps (< 1:8,000) and soil and topographical maps (> 1:15,000):

Schematic diagram of the “gap” in land management mapping, between cadastral records and natural resource maps of topography, soils, and land use (Dahlberg 1984, fig. 2). Note that the main diagonal line represents the continuum. The extent of land-use mapping actually fudges the gap discussed in Dahlberg’s text and imaged in his fig. 1. Image reproduced under fair-use provisions.]

Dahlberg’s diagram demonstrates that different kinds of mapping for different functions produce maps at different scales, and his article was concerned primarily with overcoming the differences between each set of maps. Were we to plot other kinds of maps in the same manner, we’d find each set taking up a portion of the continuum, most overlapping, and maybe some other gaps.

Thus, it is not that there is one phenomenon (map) which comes in many variants, but many different phenomena that can be arranged along a continuum only on the basis of a superficial characteristic. The proper subject of analysis is therefore not maps but the mapping processes that gave rise to them.

one kind of mapping can have multiple variants

Here’s another example of a continuum, one that blends map scale with time:

The Traditional, Progressive Narrative of the Geographical Mapping of New England

This diagram represents the kind of progressive narratives constructed by traditional map historians of the mapping of specific regions. Over time, more information accrues, and the maps get bigger until they must be broken up, and then each subordinate part of the region is mapped in ever more detail, until the maps of those regions get too big in turn and must be broken up. Each break point fractures the spatial frame of territory being mapped.

Such progressive narratives are implied by the selective compilation of cartobibliographies of maps of specific regions. In the case of printed maps of New England, Barbara McCorkle (2001) of course listed maps of New England per se but also maps of larger extent: maps of all of the Americas until 1600, after which English settlement began in earnest, generating too much information to be shown on such small-scale maps; then maps of North America until 1700, by when such maps were too small to show the region well; and then maps of eastern North America until 1800. Furthermore, McCorkle placed maps of the individual New England colonies (or states) before 1800 in a separate appendix. David Cobb (1971; 1981, esp. xiii) continued the progressive frame fracturing in his cartobibliographies of the New England states of Vermont and New Hampshire. For the period before 1800, Cobb included general maps of New England as well as maps of each state, and then progressively weeded out maps of the states, to focus on county maps, then town [n1] maps, and eventually, after 1884, topographical quadrangles by the U.S. Geological Survey (Cobb 1971; 1981, esp. xiii). The overall result is a narrative in which the regional map frame repeatedly fractures and reforms: over time, maps grow physically ever larger in order to hold ever more data, with single-sheet maps giving way to multi-sheet maps or even atlases; eventually the maps become unwieldy and are replaced by separate maps of each sub-region.

Note that this sequence brings together maps made for several different communities: geographical maps of large areas; more detailed, place maps of counties, towns, and cities; and systematic topographical maps of territory. Yoking all these different maps together in a single narrative of progressive acquisition of content is historically inept.

We should, instead, look at each kind of map separately. In doing so, we can see significant patterns. For example, among the maps of New England as a whole, which the cartobibliographies suggest cease after 1800, we can identify three distinct types of geographical map:

Discrete English Public Geographical Discourses re New England

(1) A number of maps, starting with John Smith’s map of New England (Edney 2010), were designed to fit into works that propose or celebrate the English settlement of the region, and especially settlement by the Puritans. These maps are generally small, no more than 8 x 10 inches, so that they can be folded and tipped into books. Each of these maps must be interpreted as part of the parent work and within traditions of writing about New England’s history.

(2) More maps, generally of a larger trim size, but still single-sheet, were included in educational books and general atlases. In the colonial era, such maps placed New England into the context either of the Maritimes (i.e., Massachusetts Bay’s imperium in imperio) or of the middle and perhaps southern English colonies (i.e., the mixed-economy colonies).

(3) large wall maps, starting with that by William Douglass ([1755]) and continuing well into the nineteenth century. As wall maps, these works were intended for display and must be analyzed accordingly (see Brückner 2017).

Three sets of geographical maps, all part of the same overall group of maps, yet with distinctly different processes of production, circulation, and consumption.

Moreover, separated out like this, we can quickly find many post-1800 maps of "New England" that have been dismissed as irrelevant but which suggest continuing cultural negotiations over the nature and concept of this region.

a processual approach

What these examples and complaints suggest is that the proper way to study maps, in the past as well as the present and the future, is through an overt emphasis on process, on the ways in which people produce, circulate, and consume these things called maps. A processual approach functions at two levels.

Methodologically, it offers a mechanism for studying the shifting nature of mapping practices and to offer a mechanism for diachronic analysis of mapping, as opposed to the overwhelmingly synchronic analyses of normative and sociocultural map scholars. This was the reason for my initial exposition of mapping modes, as a means to track changes over time in how maps are produced and consumed without relying on the well-established teleologies of cartographic progress (Edney 1993). As a methodology, a processual approach is not prescriptive; it does not preclude other approaches to interpreting and contextualizing maps.

Philosophically, a processual approach constitutes an explicit ontology for mapping that actively counteracts the ontology ostensibly offered by cartography. It requires that map scholars frame their research agendas in accordance with the empirical discrimination of mapping modes and more precise spatial discourses. That empirical analysis must consider all three general processes equally: not just production, as normative scholars have emphasized, nor just the consumption and interpretation of maps emphasized by sociocultural scholars, but production, consumption, and circulation together, considered equally. A processual approach demands that scholars make no a priori generalizations about the nature of the maps and mapping communities they study—whether in the past, present, or future—without first establishing how those generalizations are constrained by the particular mapping processes at play. In short, a processual approach directs scholars to be aware of their presumptions and to take nothing for granted (see Edney 1996; 2017).

Notes

[n1] The New England “town” is an area of land generally encompassing 30–40 square miles, although many towns were originally much larger when created in the colonial era; in U.S. states west of the Appalachians, such areas are generally known as “townships.”

References

Brückner, Martin. 2017. The Social Life of Maps in America, 1750–1860. Chapel Hill: University of North Carolina Press for the Omohundro Institute for Early American History and Culture, 2017.

Cobb, David A. 1971. “Vermont Maps Prior to 1900: An Annotated Cartobibliography.” Vermont History 39, nos. 3&4: 1–317.

———. 1981. New Hampshire Maps to 1900: An Annotated Checklist. Hanover, N.H.: University Press of New England for the New Hampshire Historical Society.

Dahlberg, Richard E. 1984. “The Public Land Survey: The American Rural Cadastre.” Computers, Environment and Urban Systems 9, nos. 2–3: 145–53.

Edney, Matthew H. 1993. “Cartography without ‘Progress’: Reinterpreting the Nature and Historical Development of Mapmaking.” Cartographica 30, nos. 2–3: 54–68.

———. 1996. “Theory and the History of Cartography.” Imago Mundi 48: 185–91.

———. 2010. “Simon de Passe’s Cartographic Portrait of Captain John Smith and a New England (1616/7).” Word & Image 26, no. 2: 186–213.

———. 2017. “Map History: Discourse and Process.” In The Routledge Handbook of Mapping and Cartography, edited by Alexander J. Kent and Peter Vujakovic, 68–79. London: Routledge.

McCorkle, Barbara B. 2001. New England in Early Printed Maps, 1513 to 1800: An Illustrated Carto-Bibliography. Providence, R.I.: John Carter Brown Library.