Wednesday, August 3, 2011
Hooray for Joseph Priestley
But we do know about Joseph Priestley.
I am reading Cartographies of Time, by Daniel Rosenberg and Anthony Grafton, about the centuries-long struggle to describe the passage of time visually. The book is full of illustrations of time as a tree, a circle, a human body, etc. and one is more complicated and confusing than the next.
But in 1765 scientist Joseph Priestley created a variation of what you see above, and called it A Chart of Biography, and suddenly the obscure became clear. Although the detail is too small to read any modern reader understands what he is showing us. This is a timeline, with the past on the left, the present on the right and each line marks off a time period, in this case, the lifetimes of great men. At a glance you can see who were contemporaries, who were in a position to influence each other, etc. Brilliant.
But you might argue that it only looks intuitive to us because we are used to it. Not so; the readers in the 1760s immediately understood it and started borrowing, stealing adapting, building from Priestley's invention.
Here's how good an idea this was: twenty-one years later William Playfair published his Commercial and Political Atlas in which he added another dimension to Priestley's work - quite literally. He tacked on the y-axis, and created line graphs and bar charts.