The Georgia Negro: A Social Study - Chart shows income and expenses for African Americans working eight different occupations [LCCN2013650355]
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
Instead of summarising the survey, the plate reproduces the instrument, so the reader is auditing raw returns rather than accepting a conclusion. The device that carries it is field 15 - the questionnaire itself asks for the wages of white laborers of the same grade, which means the racial pay gap is recorded as a routine clerical entry rather than asserted by the author. Handwriting does the emotional work the typography refuses to do: eight different hands, misaligned entries and answers like Spent on home make these households individual, while the repeated form keeps them comparable.
Steal this when
Use it when the credibility problem is that people suspect your numbers were cooked, and the cure is showing the unedited source records side by side. The embedded comparison field is the move to copy whenever you want a disparity to read as procedure instead of accusation.