Album de Statistique Graphique - Recettes des Lignes D'Omnibus de Paris en 1881. (Revenue of the Omnibus Lines of Paris in 1881.) [12514.025]
The pattern
This still is filed under Data as proof.
Define
A chart, map, or count that is the argument, not an illustration next to the argument.
Mechanism
Sighted evidence. The reader is asked to believe their eyes: a bar, a share, a spread on a map.
Verdict
The claim is comparative or quantitative and the figure can be read without a caption doing the sell.
Why it works
The quantity is carried by width on a real base map, so location and magnitude are read in one fixation instead of being cross-referenced between a chart and a map. Because the ribbon follows the true street path and thickens and thins along it, the reader gets the distribution inside a single line, not just its total. The olive surround is a figure-ground device: it kills everything outside the city wall so the eye cannot wander off the subject. The full numeric table is kept on the same sheet, which lets the graphic be approximate and still be trusted, since any figure can be checked without turning a page.
Steal this when
Use this when volume is attached to a physical route or network and the decision is which segments to keep, cut or fund. Also use the pairing trick: a flow map for the shape of the answer, the exhaustive table on the same surface so nobody can accuse the picture of hiding the numbers.