Timelines were the forerunners of modern bar charts and inspired the first bar chart, as well as other data visualization innovations. The idea of plotting data— such as lifespans—against time using explicit x and y axes started here.
Joseph Priestley (1733–1804). A Description of a Chart of Biography. London: J. Johnson, 1785.
Timelines weren’t exactly new when British theologian Joseph Priestley created his celebrated Chart of Biography in 1765. Priestley’s innovation was to use bars to represent lifespans, mapping the length of a bar to the length of a life, which may have been the first explicit use of an axis representing time. Priestley’s innovation allowed people to see who lived at the same time or had overlapping lifespans. The idea of a timeline with lifespans is familiar to modern audiences, but Priestley devoted twenty-seven pages of text to explain his chart and its context to eighteenth century audiences.
Priestley’s chart of biographical timelines inspired William Playfair when he invented the bar chart in 1781. Priestley also inspired Playfair’s brother James to make timelines of his own. This example, one of many in A System of Chronology, plots the lifespans of political and religious leaders. While it may seem intuitive to modern audiences that a lifespan could be repre- sented by a line segment relating to an axis with a time scale, Priestley felt that the novel concept would be difficult to accept and devoted at least seven pages of his book to convince his readers of the possibility.
Percy Robertson (1874-1960). Contemporary Authors of Former Times: A Chart and Index. Toronto, 1944?
Percy Robertson in Toronto created this other example timeline around 1944. It loses some of the charm of its predecessors to its relative modernity.
Aurora Mendelsohn (1972– ) and Anthony Gray (1968– ) Timeline of exhibition authors.
In honour of the Priestley timeline and its heritage and its place in the Fisher collection, this timeline of all the creators of data visualizations in theEmerging Patterns exhibition was created for the exhibition.
