Tableaux d'arithmetique lineaire (French edition of the Commercial and Political Atlas) - Tableau du montant de toutes les exportations et importations d'Angleterre, depuis 1700, jusqu'en l'année 1785. W. Playfaire inv [14319.054]
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
As the opening plate it has to teach the method, and it does that with one instruction under the frame: the bottom numbers are years, the right numbers are millions. After that the plate labels its own parts in place, each line named on the line and the band named inside the band, so no legend exists and nothing has to be memorised. The band is the argument and the two lines are only its edges, which is why the fill reads before either curve does. One crimson lozenge in eighty-five years marks the single exception more forcefully than any callout could, precisely because it is the only place the colour changes.
Steal this when
Use it when you are introducing an unfamiliar chart form to an audience: put the reading instruction in one plain line under the frame, then label every element in place so the reader never has to look away. Reserve a second colour for the one exception and spend it nowhere else.