William Playfair: faither o data visualisation

Ye could say that the Scots gied us the modren warld. The television, telephone, penicillin, logarithms, the first practical radar system and steam engine, free mercat economic theory — aw inventions or discoveries creditit tae Scots. It’s awmaist embarrassin. But maist fowk likely disna ken that the inventor o the time-series line graph, bar chairt and pie chairt wis a Scot an-aw. The graphs sae kenspeckle in economics, science and business the day — and gey aften the wey we unnerstaund the warld aroond us — haes their origins in the ootpit o a William Playfair. This I didna ken, and bein somewhat o a data nerd I thocht I’d dae a bit speirin intae his life and wark.

William Playfair wis born in 1759 in the wee clachan o Liff, Dundee wey. His aulder brither wis John Playfair, that gaed on tae become a famous mathematician and geologist and chair o natural philosophy at Embra University. Upon the early deith o their faither, the 24-year-auld John wis pitten in chairge o twal-year-auld William’s education. It wis John that gart William keep a register o thermometer data and record the variations as lines on a dividen scale, something that wis tae inspire William in his later wark. Atour, throu John, William wis tae become acquent wi a wheen great men o the Scots Enlichtment, sic as philosopher Dugald Stewart and economist Aidam Smith. Wi aw thir weel-leart fowk aboot him, it’s nae wunner William wad gae on tae become a fine thinker hissel and mak his ain dunt in the universe.

Afore Playfair, data wis representit in tables, that isna ower easy for a body tae tak in. For example, it wad be a fash tae indentify paiterns ower time if ye war juist starin at a table o dates and nummers. Playfair trewed that makkin data mair bonnie tae the een wad allou fowk tae gain insicht intae them and haud on tae thir insichts.¹ He remerkit anent ae history-relatit chairt in 1805: ‘I first drew the Chart in order to clear up my own ideas on the subject, finding it very troublesome to retain a distinct notion of the changes that had taken place. I found it answer[ed] the purpose beyond my expectation, by bringing into one view the result of details that are dispersed over a very wide and intricate field of universal history; facts sometimes connected with each other, sometimes not, and always requiring reflection each time they were referred to.’ I mysel fund it uissfu tae mak a bar chairt in the coorse o my speirins intae early muisic in Scotland: for tae mak compare atween muisical developments in Scotland and ither European kintraes, as weel as keep track o what wis gaun on in Scotland politically. It alloued me tae get a guid vizzie o awthing in context, something that a list o dates and events wadna affuird.

Playfair set furth his first statistical chairts in 1786 in his Commercial and Political Atlas. In it he bores intae English tred in the echteent century. The first twa editions, at Jeames Watt’s insistence,² includit traditional data tables as weel as the graphs, but by the third Playfair wis siccar eneuch in his graphical newfangles tae dae awa wi the numerical data and juist uise the graphs.

Fowk in his native Britain wisna ower taen on wi his chairts, houiver. The’ war concerns anent accuracy — and it’s true that the graphs did conteen mistaks. Playfair’s less-than-braw reputation wadna hae helpit, aitherins (mair anent that in a bit). The chairts fund mair fauvour on the continent, drawin praise by nane ither than King Louis XVI o Fraunce. But it wisna till aboot a century efterhaund that fowk realised the full extent o the importance o Playfair’s wark. Tae us the day it micht seem obvious tae present data by gate o chairts. But it wisna the case in Playfair’s time, and it wis something he wis onstaundin in threapin for, even if  he wis aft-times met wi scepticism.

In fact, success seemed tae jouk Playfair oot-throu his life, and he wis aye insnorlt in ae haundlin or ither for tae mak siller, whither it be settin furth sindry quairs (ower a hunder in total)³, or engagin in some ploy that wis tae gart him faw on the wrang side o the law. Ae scheme, in 1816, involved his seekin tae blackmail Lord Airchibald Dooglas in relation tae the Dooglas Cause, ane o the echteent century’s maist kenspeckle legal battles. The’ war allegations o embezzlement as weel as pittin in for patents for inventions no o his ain makkin, and in 1805 he wis convictit on chairges o financial malverse. Aiblins the maist by-ordinar o Playfair’s adventurs wis revealed in new research set furth in 2018 by Bruce Berkowitz. It turns oot he wis a secret agent cairyin oot espionage in Fraunce on Britain’s behauf, wi the audacious ploy o coonterfeitin siller for tae caw the feet frae unner Fraunce’s economy!

Pittin aw thir daeins — alleged or itherwise — aside, the’r nae dout that Playfair wis an innovator that haed great insicht intae hou fowk perceives data. It’s no quite the case that naebody else afore him haed thocht o pittin data intae graphical form: a wheen, isolatit line graphs can be datit tae afore Playfair. But naebody else saw their potential or threapit for them tae sic an extent as Playfair, and nae ither body cam up wi sic a variety o them, inventin aw but the scatter plot. He unnerstuid that statistics their lanes disna mak muckle sense tae, or steer up the imaginations o, your average punter. He remerkit in 1795: ‘To act upon the minds of the people at large, a work must be entertaining, periodical and cheap.’ For aw his failzies and financial cantrips, ye canna faut the man’s egalitarianism in relation tae his life’s great achievement.

Whan we consider hou iver mair important data and the analysis thereof is in the day’s high-tech, globalised societies, Playfair seems aw the mair aheid o his time. An he certainly desers a place alangside the ither Scots that brocht us the modren warld.

Bibliography and fitmerks

• Patricia Costigan-Eaves, Michael Macdonald-Ross, ‘William Playfair (1759-1823)’, in Statistical Science, 5:3, 318-326 (Institute of Mathematical Statistics, August 1990)
• William Playfair, Howard Wainer (ed.), Ian Spence (ed.), Playfair’s Commercial and Political Atlas and Statistical Breviary (Cambridge University Press, 2005)
• Ian Spence, ‘Playfair, William’, Oxford Dictionary of National Biography (online). Accessed September 2019
• Ian Spence, Howard Wainer, ‘William Playfair: A Daring Worthless Fellow’, in CHANCE, 10:1, 31-34 (1997), DOI: 10.1080/09332480.1997.10554795

1. Frae his Statistical Breviary (1801): ‘The advantages proposed by the graphical mode of representation, are to facilitate the attainment of information, and aid the memory in retaining it: which two points form the principal business in what we call learning.… Of all the senses, the eye gives the liveliest and most accurate idea of whatever is susceptible of being represented to it; and when proportion between different quantities is the object, then the eye has an incalculable superiority.’
2. For a time Playfair wrocht for Watt — that cam up wi the steam engine design that helpit pouer the Industrial Revolution — and micht hae been influenced by him: Watt wis said tae hiv uised graphics tae check watter pressure in his steam engine.
3. Playfair’s ither warks includit a critical ootgie o Aidam Smith’s famous An Inquiry into the Nature and Causes of the Wealth of Nations. He wis tuithy in his criticism o his brither Scot’s ideas, and its furthsettin wisna weel received.