Put out more flags

Did you know that 190 out of 200 nations in the world have either red or blue on their flags? (The wheel in the middle of India’s flag is blue, for example, and the Vatican flag has a red cord hanging from the keys.) Did you know that four of those 190 — Andorra, Chad, Moldova and Romania — have pretty much the same blue-yellow-red tricolour? Or that the stripes of the French flag are not of even width, but are proportioned 30-34-37? It’s an optical illusion: if the red, white and blue are of equal breadth, the flag looks curiously unbalanced.

These are among the facts that you won’t find in Tim Marshall’s Worth Dying For, a vexillological miscellany. I bring them up in no carping spirit. Rather, I’m trying to demonstrate the difficulty faced by authors of this sort of book in an age of Google. You’ve got to assume that your readers have some basic interest in your subject; and also that they are capable of looking things up online.