John Snow’s cholera map
Deaths drawn as marks stacked at each address. Putting the data on the street made the cluster around one water pump visible, and the map argued the case before the statistics could.
Preview from Wikimedia Commons, public domain, shown from their site.
By
John Snow · 1854
Where
Science & health · Epidemiology
Form
Static image · to persuade
Visual
Space, Density
Data
Deaths recorded in Soho, London
Original