Plotting the Globe: Stories of Meridians, Parallels, and the International Date Line, and: Rhumb Lines and Map Wars: A Social History of the Mercator Projection (review)

Geography and geodesy are ancient sciences wrapped in conundrums the way bittersweet chocolate enrobes a near-spherical bonbon. The earth rotates on an axis as it revolves around the sun, from which we obtain two poles and an equator. Besides these, every other element of position and place on the planet's surface is defined arbitrarily by one system or another. Well, make that one system on top of another. Why does a circle contain 360 degrees? Because it worked for the Babylonians, so it works for us. Further, the precision of positioning in any given arbitrary system is determined ultimately by alignments with moving orbs not on the earth at all, be they navigational stars or Global Positioning System (GPS) satellites. The key to earthly positioning is in the heavens, and it has been so for millennia. But wait, there's more! Once humans determine places, we like to present them, and we have a predilection for doing so on flat, smooth surfaces, be they cave walls or map papers or plasma screens. But since the earth isn't flat, any map that covers more than a trivial amount of the earth's surface must distort the size and shape and/or alignments of everything shown on the map. All of the above has been true since way before the days of Ptolemy, and nothing about it is going to change any time soon.

There is now a veritable supernova in new geographic technologies—GPS car-guidance systems and fabulous-looking digital maps and so on—but it is occurring simultaneously with the erosion or complete collapse of geographic training in primary and secondary education in the United States. The news media note how few Americans can find Iraq on a map—the scandal is how few of them can find anything on a map. What is to be done? Into the breach come authors who are providing for an adult market the type of geographic knowledge and history that their readers didn't acquire to begin with, or learned and then forgot. The caliber of the works varies, of course, but the intent to fill a yawning gap is palpable. Here are two of the more interesting and useful attempts to fill the maw. Plotting the Globe recapitulates the modern story of determining the shape of our planet: the lovely-named figure of the earth, the system of latitude and longitude, and, of course, time, which runs through the story like the invisible river it is. Rhumb Lines and Map Wars is accurately subtitled to be a social history of the Mercator projection, but it is in fact more: a lively exploration of what happens when those curves and lines of latitude and longitude lift from the planet and plop onto flat paper.

In Plotting the Globe, Avraham Ariel and his coauthor, editor, and daughter Nora Ariel Berger have written a book that feels and reads as self-published, with a lively and idiosyncratic style blissfully uncoupled from any contemporary regimes of social history or criticism. Ariel spent decades as a mariner and sea captain and he knows his subjects expertly, but when he considers Foucault he thinks only of his pendulum. There is no larger encompassing theme here, though the reader will find a fabulous cast of very lively and peculiar characters who sacrificed much of their lives to get to some desolate peak in Greenland for the briefest transit of the sun by tiny Venus. The authors have repackaged secondary sources, but they have read the most recent and best materials and assimilated them well. If you have ever wondered why the International Date Line meanders down the vast...