Playfair's Linear Chronology

Data from William Playfair's (1824) last graph, titled "Linear Chronology, Exhibiting the Revenues, Expenditure, Debt, Price of Stocks and Bread, from 1770 to 1824". The chart tracks multiple economic variables, including national debt, exports, imports, revenue, expenditure, the price of stocks, and the price of bread over a 154 year time span.

Usage

data("Playfair1824")

Format

A data frame with 55 observations on the following 9 variables.

Year

numeric, a numeric vector

Stocks

Price of Stocks (Pounds per 3% consol bond), a numeric vector

Wheat

Price of Wheat (Shillings per quarter), a numeric vector

Bread

Price of Bread (Farthings per quarter-loaf), a numeric vector

Debt

National debt (Tens of millions of pounds), a numeric vector

Exports

Exports (Millions of pounds), a numeric vector

Imports

Imports (Millions of pounds), a numeric vector

Expenditure

Expenditure (Millions of pounds), a numeric vector

Revenue

Revenue (Millions of pounds), a numeric vector

Source

Ivan Lokhov, Remaking a 200-year-old chart https://www.datawrapper.de/blog/playfair-chronology-multiple-lines

Details

Playfair's 1824 chart is a pivotal work in the history of data visualization because it uses a multiple line graphs showing time series of economic indicators over time, with a fine appreciation of the complexity and directly labeled curves. The dataset, extracted from the image by Ivan Lokhov using WebPlotDigitizer, presents a challenge in trying re-create it, or do better using modern graphics methods.

References

Playfair, W. (1824). Chronology of Public Events and Remarkable Occurrences within the Last Fifty Years; or from 1774 to 1824, published in London.

The original chart can be seen on Wikimedia at: https://bit.ly/4ihX92a

Spence, I., Fenn, C. R., & Klein, S. (2017). Who is buried in Playfairs grave? Significance, 14(5), 20–23. doi:10.1111/j.1740-9713.2017.01071.x

Examples

data(Playfair1824)
str(Playfair1824)
#> 'data.frame':	55 obs. of  9 variables:
#>  $ Year       : num  1770 1771 1772 1773 1774 ...
#>  $ Stocks     : num  79.6 76.3 78.7 75.8 77.2 ...
#>  $ Wheat      : num  NA NA NA NA NA NA NA NA NA NA ...
#>  $ Bread      : num  23.5 24.1 25.6 25.9 26.2 ...
#>  $ Debt       : num  14 14 13.7 13.7 13.7 ...
#>  $ Exports    : num  11.6 12.2 11.3 11 12.2 ...
#>  $ Imports    : num  NA NA NA NA NA NA NA NA NA NA ...
#>  $ Expenditure: num  9.21 9.21 9.22 9.22 9.23 ...
#>  $ Revenue    : num  7.72 8.03 8.03 7.74 8.04 ...

# Plot multiple time series with matplot()
matplot(Playfair1824$Year, Playfair1824[, -1],
        pch = c("S", "W", "B", "D", "E", "I", "X", "R"),
        type = "b",
        xlab = "Year",
        ylab = "value",
        ylim = c(0, 140),
        main = "Linear Chronology, Exhibiting the Revenues, Expenditure, ... from 1770 to 1824")

# main events
events <- data.frame(
  start = c(1776, 1793, 1804),
  end = c(1782.2, 1802, 1815.2),
  event = c("American War", "War: French Republic", "War: Napoleon")
)

with(events, {
  arrows(x0 = start, x1 = end, 
         y0 = 130, y1 = 130, 
         lwd = 3,
         code = 3,
         angle = 90, length = 0.05)
  text((start+end)/2, 132, event, pos = 3)
})