William Playfair (22 September 1759 – 11 February 1823), 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 a secret agent, Playfair reported on the French Revolution and organized a clandestine counterfeiting operation in 1793 to collapse the French currency. Biography William Playfair was born in 1759 in Scotland. He was the fourth son (named after his grandfather) 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 he 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 Ian Spence 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