Measuring a country: which axis, and why it changes the answer
Ask how big a country is and the honest answer is a question back: big in which direction? Area is one answer, span is another, and the 118 geographic outlines in this game are all judged on span, which means the axis has to be stated every time.
Three different questions
How big is France? There are at least three honest answers and they are not interchangeable.
- Area. The figure in every almanac. It is the right number for population density, agriculture and anything to do with surface.
- Span. The distance across the outline in a given direction. It is the right number for travel, for drawing, and for any comparison you intend to picture.
- Extent. How far the territory reaches, which for a country with overseas holdings can be a completely different thing from either.
The 118 geographic outlines in this game are all judged on span, because span is the only one of the three that can be drawn and dragged. France carries an east-west figure of 1,225.9 km.
Which axis, and who decides
For a country with an obvious long direction the choice is easy and it matches how people describe the place. Italy runs north to south, so its figure is 1,288.9 km north to south. Chile is even more extreme. Argentina, running the length of a continent, carries 3,685.6 km north to south.
For compact countries the choice is harder and the answer is that the axis has to be stated rather than assumed. Germany's figure is 868.3 km north to south, which is the longer of its two spans, though not by a wide margin. Set against Florida's east-west span of 740.3 km the ratio is 1.17, comparing a north-south figure to an east-west one, which the page states explicitly because the alternative is a silent error.
Florida is the clearest case of an axis changing the answer. Measured east to west across the panhandle it is 740.3 km. Measured north to south down the peninsula it is a different number entirely. Neither figure is the size of Florida. Both are a size of Florida.
The trap of comparing two spans
Two countries with the same span can be wildly different in area, and this is not a subtle effect. Indonesia spans 5,048.6 km east to west against China's 4,822.2 km, a ratio of 1.05, and China's land area is several times Indonesia's. The span figure is dominated by an archipelago that is mostly sea.
That is not a flaw in the measurement, it is a property of the shape. An archipelago has an enormous span and modest area by definition. The number is still the right one for the question the game asks, which is how wide is this thing on screen, and it is the wrong one for almost any question about the country as a place.
Cities and regions are worse
A country at least has a legal boundary. A city usually has two or three, and they disagree by a large factor.
Greater London spans 58.4 km east to west, and that is the administrative area rather than the continuous built-up sprawl, which runs well past it. The Greater Tokyo Area spans 194.6 km east to west and is a statistical region rather than a city at all. The ratio of 3.33 between them is therefore a comparison between two different kinds of boundary, which is worth knowing before anyone quotes it.
Singapore is unusual in being a city and a country at once, spanning 53.7 km east to west, and unusual again in that the figure moves: the island has grown measurably in fifty years through land reclamation. Against Greater Tokyo the ratio is 3.62, and the smaller number is the one that is not fixed.
Lakes, rivers and things with no edge
Water bodies are the hardest case in the set. Lake Superior spans 590 km east to west and is the largest freshwater lake in the world by surface area. Minnesota spans 655.8 km north to south, so the ratio is 1.11 between a lake measured one way and a state measured the other.
Rivers are worse still, because a river's length and a river's span are entirely different quantities. The Nile's north-south span in the catalogue is a straight-line distance across the outline, not the length of the river, which is considerably longer because rivers meander. Anyone comparing a river figure without checking which one it is will be out by a large factor.
The Caspian Sea is the borderline case, spanning 1,166.1 km north to south. It is the largest lake on Earth by surface area, and whether it counts as a lake or a sea is a question about treaties rather than about geography. Against Canada's east-west span of 5,395.3 km the ratio is 4.63, and both figures are spans of outlines, which makes it at least internally consistent.
National parks and protected areas
These have the cleanest boundaries of anything in the geographic set, because they are drawn on a map by an act of law rather than by a coastline. Grand Canyon National Park spans 210 km east to west. Switzerland spans 345.9 km east to west, giving 1.65.
What no span can convey is the third dimension. The canyon is over a mile deep, and that is the dimension nobody has ever put on an outline. A flat shape can tell you how far across something is and never how far down.
In practice
State the axis. Compare like with like where you can. Where you cannot, say so in the same sentence as the ratio rather than in a footnote. And be suspicious of any comparison of two countries that gives a single number without saying which direction it was taken in, because that number has been chosen, and it has usually been chosen to make the point the writer wanted.