Map Projections

Map Projections in the History of Cartography

5507.2 - Educating a General Readership on Map Projections in Twentieth Century Thematic World Atlases: A Survey

Wednesday, July 5
1:50 PM - 2:10 PM
Location: Maryland B

The Question
Map projections provide a structural framework for the map and work in tandem with scale and generalization to effectively communicate spatial information. As an integral component of map design an appropriately selected map projection can present the geographic area of interest so that patterns can be emphasized or spatial analysis can be conducted. Students studying cartography and other mapping science disciplines formally learn about map projections through structured coursework comprised of lectures, reading assignments, and lab exercises. While this learning environment is suitable for mapping professionals, this present survey asks “how does the general public learn about map projections”? One learning alternative is through thematic world atlases which include educational sections on map-related topics (e.g., map reading and map scale). While past research on world atlases has focused on other issues, for example map design, using world atlases as a medium for a general readership to learn about map projections has not been examined. This survey began by examining cartography textbooks to develop a baseline of map projection knowledge and how it should be presented. Then, that baseline knowledge was used to evaluate map projection information that is presented in world atlases.

The Approach
This survey examined thematic world atlases published in English during the Twentieth Century. World atlases commonly include world scale maps which compared to other scales are more sensitive to the impacts of map projections. Thus, atlas readers need to be informed as to the visual differences in world scale maps to better understand the mapped data. Other atlases such as school atlases were avoided since they are more likely to contain information on map projections as their audience is student centered rather than a general readership. The 1900s were selected as this century witnessed a variety of new map projections being developed (e.g., new pseudocylindrics) and appearing in world atlases in response to the occurrence of significant global events (e.g., two world wars and the space age).

The survey began with a content analysis of cartography textbooks published in English during the 1900s. This analysis determined which specific map projection content was common across textbooks and therefore likely to constitute fundamental map projection knowledge. Next, attention turned toward sampling world atlases. A total of 749 atlases were examined between 1900 and 200 that included information on map projections. It was noted that only 27% of this number included map projection information. This atlas subset was then used to compile what specific map projection knowledge was included and how it was presented compared to what textbooks considered necessary.

The Results
The content analysis showed that cartography textbooks embraced both text and illustrations to teach map projection knowledge. Throughout the time period, topics included the basic developable surfaces, classes of projections, arrangements of the graticule, and distortion. Distortion was discussed in approximately 35% while the other three topics were included in nearly 90% of the atlas subset. While textbooks universally included illustrations supporting these topics, atlases showed differences. Nearly 85% of the atlases included illustrations of the developable surfaces, basic classes, and graticule arrangements, but less than 5% of the atlases included illustrations supplementing distortion. No atlas surveyed included Tissot’s indicatrix which is a popular graphic used in textbooks to illustrate distortion. Projection properties was another universal topic found in textbooks. However, this topic was only discussed in 37% of world atlases. Not surprisingly, methods of graphical construction appeared frequently in the first half of the century in both textbooks and atlases but by the 1970s had faded as computers replaced manual drafting techniques.

Fritz Kessler

Senior Research Associate
The Pennsylvania State University

Fritz Kessler, a Senior Research Associate and Associate Professor in the Geography Department at Pennsylvania State University, teaches online and residential courses in cartography, map projections, spatial statistics, and GIS. Research interests include map projections and cartographic history. Publications include: Thematic Cartography and GeoVisualization and articles in Annals of the Association of American Geographers, Cartographica, Cartography and Geographic Information Science, and Journal of Geography. Professional cartographic experience includes positions with the USGS, Intergraph, R.R. Donnelley and Sons, and the T.R. Smith Map Library. He actively serves the North American Cartographic and Information Society and the Cartography and Geographic Information Society.

Presentation(s):

Send Email for Fritz Kessler

Fritz Kessler

Senior Research Associate
The Pennsylvania State University

Fritz Kessler, a Senior Research Associate and Associate Professor in the Geography Department at Pennsylvania State University, teaches online and residential courses in cartography, map projections, spatial statistics, and GIS. Research interests include map projections and cartographic history. Publications include: Thematic Cartography and GeoVisualization and articles in Annals of the Association of American Geographers, Cartographica, Cartography and Geographic Information Science, and Journal of Geography. Professional cartographic experience includes positions with the USGS, Intergraph, R.R. Donnelley and Sons, and the T.R. Smith Map Library. He actively serves the North American Cartographic and Information Society and the Cartography and Geographic Information Society.

Presentation(s):

Send Email for Fritz Kessler


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