William Playfair


William Playfair, a Scottish engineer and political economist, served as a secret agent on behalf of Great Britain during its war with France. The founder of graphical methods of statistics, Playfair invented several types of diagrams: in 1786 the line, area and bar chart of economic data, and in 1801 the pie chart and circle graph, used to show part-whole relations. As secret agent, Playfair reported on the French Revolution and organized a clandestine counterfeiting operation in 1793 to collapse the French currency.

Biography

Playfair was born in 1759 in Scotland. He was the fourth son of the Reverend James Playfair of the parish of Liff & Benvie near the city of Dundee in Scotland; his notable brothers were architect James Playfair and mathematician John Playfair. His father died in 1772 when William was 13, leaving the eldest brother John to care for the family and his education. After his apprenticeship with Andrew Meikle, the inventor of the threshing machine, Playfair became draftsman and personal assistant to James Watt at the Boulton and Watt steam engine manufactory in Soho, Birmingham.
Playfair had a variety of careers. He was in turn a millwright, engineer, draftsman, accountant, inventor, silversmith, merchant, investment broker, economist, statistician, pamphleteer, translator, publicist, land speculator, convict, banker, ardent royalist, editor, blackmailer and journalist. On leaving Watt's company in 1782, he set up a silversmithing business and shop in London, which failed. In 1787 he moved to Paris, taking part in the storming of the Bastille two years later. After the French revolution, Playfair played a role in the Scioto Land sale to French settlers in the Ohio River Valley. He returned to London in 1793, where he opened a "security bank", which also failed. From 1775 he worked as a writer and pamphleteer and did some engineering work. In the 1790s, Playfair informed the British government on events in France and proposed various clandestine operations to bring down the French government. At the end of the 1790s he was imprisoned for debt in the Fleet Prison, being released in 1802.

Work

and Howard Wainer in 2001 describe Playfair as "engineer, political economist and scoundrel" while "Eminent Scotsmen" calls him an "ingenious mechanic and miscellaneous writer". It compares his career with the glorious one of his older brother John Playfair, the distinguished Edinburgh mathematics professor, and draws a moral about the importance of "steadiness and consistency of plan" as well as of "genius". Bruce Berkowitz in 2018 provides a detailed portrait of Playfair as an "ambitious, audacious, and woefully imperfect British patriot" who undertook the "most complex covert operation anyone had ever conceived".

Bar chart

Two decades before Playfair's first achievements, in 1765 Joseph Priestley had created the innovation of the first timeline charts, in which individual bars were used to visualise the life span of a person, and the whole can be used to compare the life spans of multiple persons. According to James R. Beniger and Robyn "Priestley's timelines proved a commercial success and a popular sensation, and went through dozens of editions".
These timelines directly inspired Wiliam Playfair's invention of the bar chart, which first appeared in his Commercial and Political Atlas, published in 1786. According to Beniger and Robyn "Playfair was driven to this invention by a lack of data. In his Atlas he had collected a series of 34 plates about the import and export from different countries over the years, which he presented as line graphs or surface charts: line graphs shaded or tinted between abscissa and function. Because Playfair lacked the necessary series data for Scotland, he graphed its trade data for a single year as a series of 34 bars, one for each of 17 trading partners".
In this bar chart Scotland's imports and exports from and to 17 countries in 1781 are represented. "This bar chart was the first quantitative graphical form that did not locate data either in space, as had coordinates and tables, or time, as had Priestley's timelines. It constitutes a pure solution to the problem of discrete quantitative comparison".
The idea of representing data as a series of bars had earlier been published by Jacobus de Sancto Martino and attributed to Nicole Oresme. Oresme used the bars to generate a graph of velocity against continuously varying time. Playfair's use of bars was to generate a chart of discrete measurements.

Graphics

Playfair, who argued that charts communicated better than tables of data, has been credited with inventing the line, bar, area, and pie charts. His time-series plots are still presented as models of clarity.
Playfair first published The Commercial and Political Atlas in London in 1786. It contained 43 time-series plots and one bar chart, a form apparently introduced in this work. It has been described as the first major work to contain statistical graphs.
Playfair's Statistical Breviary, published in London in 1801, contains what is generally credited as the first pie chart.

Counterfeiting operation

In 1793 Playfair as secret agent devised a clandestine plan that he presented to Henry Dundas, who was Home Secretary soon to become Britain's Secretary of State for War. Playfair proposed to "fabricate one hundred millions of assignats and spread them in France by every means in my power." He saw the counterfeiting plan as the lesser of two evils: "That there are two ways of combatting the French nation the forces of which are measured by men and money. Their assignats are their money and it is better to destroy this paper founded upon an iniquitous extortion and a villainous deception than to shed the blood of men." Playfair forged the assignats at Haughton Castle in Northumberland and distributed them according to an elaborate plan. The plan apparently worked: by 1795 the French assignat had become worthless and the ensuing chaos undermined the French government. Playfair never told anyone about the operation.

Playfair cycle

The following quotation, known as the "Playfair cycle," has achieved notoriety as it pertains to the "Tytler cycle":

Works