"Figurative Map of the successive losses in men of the French Army in the Russian campaign 1812–1813.
Drawn up by M. Minard, Inspector General of Bridges and Roads in retirement. Paris, 20 November 1869.
"The numbers of men present are represented by the widths of the colored zones at a rate of one millimeter for every ten-thousand men; they are further written across the zones. The red [now brown] designates the men who enter into Russia, the black those who leave it. —— The information which has served to draw up the map has been extracted from the works of M. M. Thiers, of Segur, of Fezensac, of Chambray, and the unpublished diary of Jacob, pharmacist of the army since October 28th. In order to better judge with the eye the diminution of the army, I have assumed that the troops of prince Jerome and of Marshal Davoush who had been detached at Minsk and Moghilev and have rejoined around Orcha and Vitebsk, had always marched with the army.
"The scale is shown on the center-right, in "lieues communes de France" (common French league) which is 4444 m (2.75 miles).
"The lower portion of the graph is to be read from right to left. It shows the temperature on the army's return from Russia, in degrees below freezing on the Réaumur scale. (Multiply Réaumur temperatures by 1¼ to get Celsius, e.g. −30 °R = −37.5 °C) At Smolensk, the temperature was −21° Réaumur on 14 November" (Wikipedia)