Map projections and the historical imagination

At the New Republic, Susan Schulten has a fascinating article about maps made by Richard Edes Harrison during World War II. Schulten writes that Harrison, an artist and not a cartographer, changed the American public’s perception of the war and world by refusing to use the Mercator projection. Instead, he drew maps from various perspectives above the earth, evoking “the perspective of a pilot, but one placed at an infinite distance.”

Richard Edes Harrison, ‘Europe as Viewed from the U.S.S.R.’ (1944). Courtesy of David Rumsey Map Collection.

Schulten writes:

Most professional cartographers celebrated his provocative style for its ability to foster a more dynamic understanding of geographical relationships … . [H]is goal was to wrench Americans out of a two-dimensional sense of geography, and embrace an understanding of perspective and direction.

Much of maps that historians make on the web is also limited by the Mercator projection. Google Maps, Stamen, and Map Box all use a “Web Mercator” projection for the tiles they provide. If you’ve used a web map that pans and zooms, it was almost certainly created in the Mercator projection. Even if there are good technical reasons for Google to use that projection, historians have their own purposes that could be better served by alternative perspectives on the earth.

The world seen from Google.

According to Schulten, Harrison never thought of himself as a cartographer, and “cartographers were quick to point out that no such perspective existed in nature.” But thanks to the work of Mike Bostock and Jason Davies, the kinds of perspectives that Harrison used are available to web mapmakers.1 As part of the geographic projections available in D3, Bostock has created a satellite projection, with which the mapmaker can control the view of the earth as from a camera mounted on satellite. Such a map could be combined with any of the visualization techniques—choropleth shading, bubble maps, place names—for which D3 is known.

An example of Bostock’s satellite projection.

Jason Davies has gone a step further and figured out how to re-project Mercator map tiles into any map projection.2

Davies’s reprojected map tiles for a satellite projection.

This means that historians have the tools they need to re-imagine their historical maps outside of the constraints of any particular map projection.3 Just as Harrison changed the public view of the geopolitical situation with his perspective maps, so historians would have a powerful imaginative and rhetorical tool at their disposal if they could choose the perspective of their maps. One can imagine, for example, a map that redraws the Atlantic slave trade from the perspective of West Africa, or a map that literally faces east from Indian country. As is often the case when I read Schulten’s work, the historical maps she studies provide a useful suggestion for how historians could make their own maps to imagine the past.

Looking east over the Chesapeake.

  1. There are many other artistic elements to Harrison’s work, such as the exaggerated topography, that it would be difficult to reproduce in a programmatic map.
  2. An example showing how Davies’s method for re-projecting tiles works.
  3. Such perspectives have been available in Google Earth for many years, but asking viewers to drop into a proprietary application prevents the integration of web maps with prose narrative and argument.