Noted cartographers Denis Wood and John Fels likewise understand the cultural work of the map but also acknowledge its fundamental composition as a sign system that is comprised of both word and image when they describe a map’s meaning as tied to the interplay of visual and textual elements inherent in its display: “As word lends icon access to the semantic field of its culture, icon invites word to realize its expressive potentials in the visual field. The result is the dual signification virtually synonymous with maps, and the complementary exchange of meaning that it engenders” (Wood and Fels, “Designs on Signs” 80). Acknowledging the semiotic components of the map, cartographer David Turnbull notes that cartographic representation generally falls under two main categories: iconic and symbolic. Aligned with Peirceian semiotics, Turnbull understands iconic representation as bearing a direct likeness to the feature it describes; it attempts “to directly portray certain visual aspects of the piece of territory in question,” whereas a symbolic representation taps into social contexts in order to make meaning, and makes use of “purely conventional signs and symbols, like letters, numbers, or graphic devices” (3). Many Western maps employ both iconic and symbolic features; however, this is not to say they explicitly distinguish between the two modes of representation. Rather, these two modes are common and implicit functions of cartographic convention and representation.5
Selectivity
Similarly, Ben Barton and Marthalee Barton note that part of how the map creates meaning is through its selectivity, or through the inclusion and exclusion of information (55). Lawrence Prelli also demonstrates the notion of the rhetorical selectivity of display in his analysis of the Georges Bank and the boundary line dividing “United States and Canadian jurisdiction over resources in the Gulf of Maine” (90). At stake in the debate over these boundary lines was control of the lucrative fisheries in the region (90). Here, Prelli examines how maps and graphics were used selectively by both parties to influence “how the gulf’s features were seen and disposed the attitudes of those who saw them” (91). In doing so, Prelli explores the idea of “visual taxis,” or how visual artifacts may be implemented in the strategic structuring of an argument “for maximum persuasive effect with particular, targeted audiences” (92).6 As Barton and Barton and Prelli emphasize, selectivity is clearly a large component of visual and material representation. Turnbull too agrees that while the map cannot possibly account for or “display all there is to know about any given piece of the environment,” for a visual representation of space to be deemed a map, it “must directly represent at least some aspects of the landscape” (3).
Scale and Projection
In addition to understanding selectivity as a component of cartography’s epistemic capacity, projection and scale also shape how the map conveys particular meaning. Maps rely on scale to “bring the world-view to manageable proportions” (Dorling and Fairbairn 25). Maps that represent the whole earth on a single piece of paper or on a computer screen, for example, are “small-scale” maps, because they convey relatively little detail about a vast area within a small space. By contrast, a map of a city park that portrays “the landscape, other spatial features and their variation in great detail over a limited tract of space” can be considered a “large-scale” map, because a unit of measurement such as 1 centimeter on the map may be equivalent to 5 meters on the ground (25). What counts as large-scale or small-scale more precisely, however, is “subject to enormous subjective individual variation,” and so these terms are not generally understood as conveying precision (25).
The idea of projection helps account for how “the irregularity of the earth’s surface can be precisely addressed on a two-dimensional plane” (Dorling and Fairbairn 25). Barton and Barton describe projection schemes like the Mercator view as potentially sustaining visual distortions that “are embodied in the cartographic space as a grid” (58). Thus, they view the grid as an ideologically-charged representational device that has a propensity toward distortion, despite the fact that its purported goal is to convey accurate models of the terrain by positioning space along equal lines of latitude and longitude (58). Turnbull also points out that the grid is socially constructed and that it does not correspond with a specific physical reality or territory (26). Thus, a generic convention of the map in Western culture is its imposition of the grid onto the landscape it represents. Like Barton and Barton, Turnbull and geographer Mark Monmonier both note the potential distortions that may result from the use of various map projections. The round Earth cannot be projected onto a flat, two-dimensional surface without some level of distortion; as a result, Turnbull says, various projections have been devised to account for this issue (6). While “no one projection is the best or the most accurate,” different types of projections have different purposes for which they are more or less well-suited: “A particular projection is selected by the mapmaker on the basis of functional and perhaps aesthetic criteria, or because of a specification or convention” (Turnbull 6). Monmonier expresses a wariness when describing distortions resulting from the Mercator projection, which he feels is a “demonstrably bad choice” in projection for any map “not related to navigation” (Mapping it Out 53). As chapter five describes in greater context, the Mercator projection is most useful in sea navigation, wherein a straight line represents the actual compass bearing. This projection, however, “so grossly distorts areas and distances that the poles lie off the map at infinity” (Monmonier, Mapping it Out 48). No other projection, Monmonier feels, has been “so abused in the pursuit of size distortion” (How to Lie with Maps 94).
Maps Constitute Ways of Seeing
Maps are thus context-bound and create meaning through their selectivity, their use of particular cartographic conventions, their imposition of the grid, the expectation that at least some aspects of the landscape are represented, and their use of both iconic and symbolic features. How, then, may the map be defined? For Turnbull, “[m]aps are graphic representations that facilitate a spatial understanding of things, concepts, conditions, processes, or events in the human world. [. . .] [The map is a] graphic representation of the milieu, containing both pictorial (or iconic) and non-pictorial elements” (3). Maps are then partial, selective representations of the world; they are always in flux and respond to their shifting contexts and relations. Their use of lines, colors, and other graphical features are likewise responses to particular social and cultural contexts and “relational engagements” (Harris and Hazen 51). Crampton also views the act of mapping as a relational cultural practice, one that needs to look outside of itself as much as it looks within; in other words, he is interested in the contexts and conditions that allow for different types of cartographic meaning to come into being (52).7 Crampton understands the map not only from the vantage point of its work as an inherently ideological document but also as one that goes on to invite interpretation and various contextualized readings. These contextualized readings may happen outside of the discipline that produced the artifact, and while those disciplinary practices must not go unchecked, the cultural work of the map extends far beyond the site of its production to influence the material worlds and bodies that it represents. Pickles also understands cartographic practice as functioning beyond the production of the artifact itself (an idea supported by Finnegan as well), and as tied to the larger project of understanding how space influences embodied experience. Here, Pickles quotes from Denis Wood when he notes that “the practice of map use is not to send a message, but to bring about a change in the way another person, or group of people, see the world. It is ‘out of their interaction in the social worlds they inhabit that people bring forth cultural products like maps’” (qtd. in Pickles, A History of Spaces 66). One example of a map that has arguably brought about a change in how people see the world is photo 22727.
The Rhetorical Work of NASA Photo AS17–148–22727: The Blue Marble
NASA’s photograph AS17–148–22727, taken during Apollo’s final journey in December of 1972, is an ideal image through which to briefly demonstrate the connections between visual rhetoric