From Cleveland (1993): In 1801, William Playfair published his Statistical Breviary, which contains many displays of economic and demographic data. One display, beautifully reproduced by Tufte, graphs the populations of 22 cities by the areas of circles. The graph also contains a table of the populations, so we can compare the data and the areas of the circles.
playfair
A data frame with 22 rows and 2 variables:
city
population
diameter of the circle in the figure
Cleveland W. S. (1993). “Visualizing Data”. Hobart Press.