Customer Reviews

Rhumb Lines and Map Wars: A Social History of the Mercator Projection

5 star:		(0)
4 star:		(1)
3 star:		(0)
2 star:		(0)
1 star:		(0)

 

 

I understand the rage that the professional cartographer class feel for the waning advocates of Gall-Peters projection. I really do: Cartographers have, over the centuries, developed probably more equal-area maps than any other sort of map projection (after all, the mathematics of equivalence are simpler than the mathematics of conformality or equidistance), producing myriad equivalent maps from the pseudocylindrical sinusoidal map (possibly invented by Mercator himself) to the more comely elliptical Mollweide projection and its superficially similar but mathematically distant pseudoazimuthal cousin, the Hammer-Aitoff projection to Lambert's equal-area conic projection. When Mercator's conformal cylindrical projection acquires widespread, inappropriate use, the cartographic professionals quietly fight for less distorting projections. Then, in waltzes Arno Peters, with an accidental copy of a map-projection invented in the mid-19th century by James Gall, calling the establishment cartographers exploiters of the developing world and apologists for Western imperialism. Adding insult to injury, Peters at times seemed to claim to be the first area-equivalent map, although he admitted that there had been earlier ones when pressed upon the point. If that weren't enough, Peters' projection displayed a Eurocentric bias in some ways more pronounced and deliberate than Mercator projection: after all, Mercator projection has no standard parallels to choose, but Peter projection requires a choice of standard parallels: Lambert, in originally formulating the cylindrical equal-area projection, chose the equator by default. Walter Behrmann moved the standard parallels to 30 degrees North/South of the equator, after some mathematical analysis trying to minimize distortion. Peters decided on 45 degrees as the standard parallels to minimize the distortion of Europe and other prosperous, temperate climes, at the expense of massive stretching and distortion of impoverished tropical regions. Some advocate for those oppressed by Western cartography!

It is thus not out of sympathy for the cause of Peters-enthusiasts or antipathy to the cause of the professional cartographers that I report that Rhumb Lines and Map Wars is too driven by anti-Peters zeal to offer a fully useful history of the contreversies. The title "Rhumb Lines and Map Wars: A Social History of the Mercator Projection" suggests a neutral, arms-length, critical portrait of all involved. A better title might have been, "Why Robinson, Snyder, et al Were Right and Peters Was Wrong." This book is a polemic. It is a polemic in favor of "my side" of this debate, but that does not make it an unbiased history.

Nonetheless, with this caveat, the book is an enjoyable read. The book traces a fascinating history, beginning with the Portalan charts that predated the Mercator projection and the Plate Caree maps that converted lattitude and longitutde into x and y coordinates without any mathematical transformation to the modern controversies over scholastic wall maps and the attempts to create acceptable compromise maps such as Robinson's "orthophanic" projection and the blended Winkel Tripel projection. While the central story of the book is the war between the entrenched, habitual use of Mercator projection, the misguided attempts to replace it with Peters projection, and the earnest efforts of cartographers to steer through the reefs of these rectangular projections be creating compromise alternatives, many other stories are told along the way, such as Ferdinand Hassler's tempermental service as the U.S.'s cartographer and inventor of polyconic projection and John Parr Snyder's rise from chemical engineer and amateur map projection enthusiast to the foremost authority on map projections with his invention of Space Oblique Mercator for NASA.

Overall, this is a good book: it is full of fascinating history and information about maps. No mathematical background is needed to understand this book's discussion of map projection. At the same time, be aware that the author is not an objective viewer of the conflict between established cartography and Peters, but an active polemicist for established cartography. This is, on balance, not such a bad thing, because established cartography is factually correct in general, but one must be aware of his intent.