A rare Georgian clock, capable of recording changes in air pressure and used at the dawn of climate science, has been acquired for the nation by the Science Museum. The barograph clock is one of only four of its type that highly-regarded London clockmaker Alexander Cumming is known to have constructed. It was used by renowned meteorologist Luke Howard to conduct some of the world’s first urban climate studies. It will now be used to tell the story of Howard’s life and his contribution to meteorology.
Following Cumming’s death in 1814, Howard purchased the clock and used it for observations of atmospheric pressure at his homes in London and Ackworth, a crucial project in the emergence of climate science. The data from the barograph traces, accompanied by notes on global weather events and descriptions of the clock, were published in the book Barometrographia in 1847. Howard’s life’s work has earned him the nickname ‘the father of scientific meteorology’ and he was also known as the ‘namer of clouds’ for naming the three principal categories of clouds – cumulus, stratus, and cirrus.
Inside the 7ft 2in-high decorated case, thought to be made by famed London cabinet maker Thomas Chippendale, is a barograph mechanism used for measuring air pressure. The barograph comprises two tubes of mercury in which a float rises and falls as atmospheric pressure changes. This data is recorded on the clock dial, which rotates once a year.
A fine example of the technical innovations of the Georgian period, the clock was designed by Cumming using ideas first outlined by Royal Society founding member Robert Hooke.
During the Georgian period, scientific practice was often presented in public as a high-status activity expressed through ornately decorated and very finely constructed instruments such as this, and in fact the first barograph clock that Cumming constructed was commissioned by King George III as a prime example of his pursuit of Enlightenment.