Thursday, 5 April 2012

Gerardus Mercator

[The following was written last month for a certain UK broadsheet newspaper to mark the 500th anniversary of Gerardus Mercator's birthday (5th March 1512).  The editor who commissioned it liked it, and it was set to run on the Friday preceeding the actual anniversary, a fact recorded in its opening sentence.  Then the editor went on holday, and somebody else at the paper bumped it for something more topical.  So it goes, and the guy who commissioned it was actually apologetic when he returned from his hols, which was decent of him and doesn't always happen in one's relations with newspapers.  At any rate, I chanced across it on my hard drive this morning and thought I'd post it here.]

Next Monday is the 500th birthday of Gerardus Mercator, and I think we ought to celebrate. Float many balloons printed with a map of the Earth upon them. And fly many rectangular flags bearing a 2D projection of those same geographical features. We may not think about him this way, but Mercator has had a profound impact upon the way we mentally situate ourselves in the world.

He was born in the Flemish Netherlands on 3 March 1512, as Gerard de Gemor; ‘Mercator’—appropriately enough for a man whose cartography would so facilitate global trade, the word means ‘merchant’—being his Latin name. Schooled by the famous George Macropedius (the man with the Best Teacher-Surname In The History Of Education) he worked as an engraver of brass plates, and then as a cartographer. There was money in this last business, as the Age of Exploration and more importantly Commerce needed good maps.

The problem with making maps is that there is no way to reproduce the figures on the 3D surface of a sphere upon a 2D sheet of paper without distortion. There is bound to be some stretching and straining. One solution is to divide the surface of the sphere into a dozen-or-so almond-shaped strips, printing sections of the world (fat at the equator, tapering towards the two poles) on each. Mercator pioneered the manufacture of globes this way, actually: printing these so-called ‘gores’ and then gluing them jigasaw-like onto a wooden or papier-maché globe. But they’re not much use in flat-maps, turning what is a continuous plane into slatted, discontinuous cartography. Mercator’s solution to that problem appeared in the late 1560s: the Mercator Projection. This accurately represents lines of latitude but treats the lines of longtitude as parallels (in fact lines of longtitude all converge at the poles), stretching the continents upon a horizontal-and-vertical grid. It’s a neat solution, and it has the advantage of enabling navigators to plot more-or-less straight lines from port to port with some accuracy. It is, by some metrics, the most widely reprinted type of global map.

It’s the fact of its global scope that is so significant, of course. Before Mercator, most maps were local maps; because most people lived purely local lives. Many were oriented with the east at the top (because that’s where the sun comes from) rather than the North. There were some maps that purported to represent the whole world, of course; but they tended to be exercises in religious-shaped wishful thinking. It was assumed that Jerusalem was at the world’s centre, and that a great ocean flowed around its rim; and many an example of Mappi Mundi, though beautiful, are about as useful for finding your way about as the map of Middle Earth at the beginning of Lord of the Rings.

We no longer live in a local world. Even if we do not travel, we exist globally; with a global awareness. And that awareness owes much more to Mercator than is usually admitted.

I once lost a bet a school: a friend said Australia was the largest island in the world. I said Greenland. I was wrong: Greenland’s appearance on the standard Mercator projection is misleading, as if the territory were afflicted with cartographic elephantiasis. The further north and south you go in Mercator’s cartography, the more misleadingly swollen the landscape is. It’s like a map of some skinny jeans that shows them as a teepee-shaped pair of flared trousers.

This distortion doesn’t matter as long as you know that it is a distortion; and having lost the bet to my friend I was careful not to be wrong again. But the ways this visualisation of the world influences our thinking are manifold, and subtle. In a sense, he’s the man who invented the West.

There are two ways of disposing the bulky twin landmasses into the Mercator frame so that the left and right margins do not cut into the land itself: you can put America on the left, or on the right. Some maps follow the latter route; many more the former, and this has the effect of positioning not Jerusalem but Europe as The Centre Of The World. I’m proud of my home continent, but I have to admit it makes no more sense to position it as the world-navel than it would to give that honour to Indonesia, or Peru, or Siberia. But ideas are powerful, and ideas that can be visualised more powerful still, and it’s hard to shift the sense that the world revolves around Europe.

Another effect of Mercator’s projection is to exaggerate the size, and therefore the apparent global importance, of North America. I don’t need to labour the point, the ways in which this might subconsciously feed into a mindset that sees the rest of the world as subsidiary to the USA.

Or to be less political for a moment: we might think of the poles as barren, purely notional points on the terrestrial globe, lacking in interest. But the Mercator map represents them as places where topography becomes infinite, dots expanded to equator-length lines, huge and inviting unmapped continents. Accordingly thousands of explorers have devoted their lives to going there, and the poles occupy a disproportionate space in many people’s imagination.

The Mercator map is a fine and beautiful thing; so fine and beautiful that we tend to mistake the map for the territory.