Bar Graphs, Pie Charts, and Darwin

One of Ms. Sandwalk's ancestors is William Playfair (1789 - 1823). Her great grandfather—the great-great-grandfather of my children—was John Playfair Leslie. John's mother is a direct descendant of William Playfair.

William Playfair was an interesting man for many reasons. He is most famous for inventing statistical graphs; especially pie charts and bar graphs. These were printed in his famous book, Commercial and Political Atlas, published in 1786. Two examples of figures from that book are shown here.

But that's not all that Playfair did. His biographers call him an "engineer, political economist and scoundrel." I won't talk about the "scoundrel" part except to mention that it's probably an accurate description. One of the more legal things he did was to participate in the storming of the Bastille on July 14, 1789. (See William Playfair for some of the less legal activities.)

William Playfair was born in Scotland and lived with his older brother John Playfair in Edinburgh. John Playfair was a distinguished Professor of Mathematics at the University of Edinburgh. Their other brother was the architect James Playfair.

William Playfair was trained as an engineer with Andrew Meikle, the inventor of the threshing machine. Following his apprenticeship, he joined the company Boulton & Watt in Birmingham, England. This company operated a large plant that manufactured steam engines. William Playfair was assistant to James Watt.

It was during his time in Birmingham that Playfair made the connection that's so important to readers of Sandwalk.


In Birmingham, William Playfair associated with the members of the Lunar Society and attended their meetings. In addition to Matthew Boulton and James Watt, his bosses, there were other members whose names may be familiar; Josiah Wedgewood, Joseph Priestly, and Erasmus Darwin. Erasmus is Charles Darwin's grandfather. Josiah Wedgewood was Charles Darwin's other grandfather.

I keep hoping that one or more of my ancestors would have known Charles Darwin or even been related. No such luck. This is as close as it gets. My wife and children have an ancestor who hung out with Erasmus Darwin and Josiah Wedgewood.

I'm jealous.

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