Denison invents Gravity Escapement Edmund Beckett Denison (Lord Grimthorpe) created the revolutionary double three-legged gravity escapement for the construction of the Great Clock of Westminster (commonly known as Big Ben) in London, which was installed in 1859. Denison was a member of the Privy Council overseeing the plan that the Royal Astronomical Society had put forth for the Great Clock’s construction. The project was exceedingly difficult, as the clock’s face was to measure almost 9 metres across, the hands were large and very heavy, and the clock had to be robust enough to withstand wind and rain. It also needed to remain accurate to within one second a day and chime every quarter hour. Denison’s gravity escapement ensured that all these conditions could be met, and since then, has been considered the ideal escapement for use in tower clocks. Image Credit Sir Edmund Beckett (known as Edmund Denison) by Henry William Pickersgill, 1850. Science Museum Group Collection © The Board of Trustees of the Science Museum, CC BY-NC-SA 4.0, https://collection.sciencemuseumgroup.org.uk/objects/co8015813/sir-edmund-beckett-known-as-edmund-denison-painting-oil-painting-portrait
