We don't do a lot of history on TreeHugger, but we do show a lot of graphs. The great Battle of Borodino was two hundred years ago today, where Napoleon lost a third of his army and essentially ended his invasion of Russia. In 1861, Charles Joseph Minard drew this graph that shows the campaign, with a wide river of soldiers moving east and a tiny trickle staggering home. Edwarde Tufte writes that it seems to "defy the pen of the historian by its brutal elegance."
Minard's graphic tells a rich, coherent story with its multivariate data, far more enlightening than just a single number bouncing along over time. Six variables are plotted: The size of the army, its location on a two-dimensional surface, direction of the army's movement, and temperature on various dates during the retreat from Moscow.
It may well be the best statistical graphic ever drawn.