WILLIAM PLAYFAIR

In 1801 CE, just over 1.6 million people were living in Scotland. The current figure is circa 5.5 million. This development, showing near-linear growth influenced by industrialisation, migration, and wars, is readily depicted on a histogram or a time-series chart.

Moving to the present-day, we find that the political landscape of Scotland differs from the wider UK. Today, the Liberal Democrats seem to garner 12% popular support nationally, placing it 5^th, whereas just a 9% Scottish share puts it in 4^th place. Political divergences are readily shown on a vivid pie chart. Compiled by a pollster and available in seconds via a laptop.

The immediate availability of informative data is a product of affordable computing and the Internet. Self-evident. More fundamentally, though, what about these revealing charts? Another invention, an older one.

For this we regress to 1759 CE, when Scotland’s population was just 1.3 million, but increased slightly with the birth of William Playfair, close to Dundee. A man with a career as colourful as any pie chart. Despite being the son of a Church of Scotland minister, seemingly there was nothing godly about his life. A brief perusal of the record unearths descriptions including rogue, scoundrel, rascal, and blackmailer. James Watt, in Birmingham, who employed him fleetingly, described him as a blunderer. Sued, almost jailed for fraud, he bolted to France, where his schemes included the sale of American land to the local aristocracy. He didn’t actually own these tracts.

Thus far, scarcely a shining archetype of the Scottish Enlightenment. More positive traits that may be distilled include energy, imagination, and intelligence. Fearlessness, too, epitomised by a trail of abortive commercial enterprises. Silversmithing and investment banking among them.

Amidst the chaos, one lesson from his childhood endured: the meticulous recording of data. His older brother, John, later a renowned mathematician, required young William to capture the daily ambient temperature, its magnitude visually depicted by the length of a line in a table. In Playfair’s own words, 'whatever can be expressed by numbers, may be represented by lines'. In 1786 CE, he published The Commercial and Political Atlas, summarising the economics of various European countries for which he had data; the work was filled with line and bar charts. Recognisable today. A later book leveraged pie charts.

While his efforts demonstrated ingenuity, they were unsympathetically received. His creations were not entirely new. Scientists, engineers, and economists were already using graphs casually to explore ideas and correlations but lacked the means to present them formally. Playfair, because of his training under the gimlet eye of Watt, had acquired an appreciation of precision and a draughtsman’s capacity for illustration.

More fundamentally, 18^th century academics disapproved of graphics. Educated readers were accustomed to eloquent arguments, conceivably supported by a table containing figures, but not trivialities. Charts were regarded as a distraction from the proposition.

Playfair’s endeavours essentially flopped. His ideas were premature, disregarded by the intended recipients who probably spurned him. Maybe he was unwelcome in respectable society. He died in 1823 CE, in obscurity and relative poverty.

His ideas manifestly survived. Others soon adopted and adapted them. Florence Nightingale applied these notions to military mortality rates and subsequently to communal living conditions. The first female entrant to the Royal Statistical Society. Occasionally described today as ‘the lady with the data’. She succeeded where Playfair failed, proving charts were not mere trivialities but vital tools for saving lives and driving social reform.

Now, we live in a data-rich era. Public health, government, sport, marketing, and economics would be impoverished without readily absorbable depictions of relationships and progress. Today, we have recurrent doubts over data integrity. Fake news is a common term.

How should we leave William Playfair? A mover and shaker who ultimately convinced few, despite a legacy of cleverness. A scoundrel, perhaps, a statistical anomaly, certainly.