The Doomsday Clock – created after the Second World War to serve as a graphic reminder that the end may be nigh – is currently set at a hundred seconds to midnight, the nearest to that hour it has ever come. But humans worried about the passage of time long before they invented devices to measure it. In his splendidly thought-provoking About Time, David Rooney insists that horological change is driven by the desire for power as well as advances in technology. Size matters: during the 18th century, the ruler of Jaipur advertised his reign by constructing a colossal sundial some forty metres across; in our own century, the Saudi government helped to construct what is currently the world’s largest mechanical clock – a giant Big Ben lookalike in Mecca, a city closed to non-Muslims, completed in 2012 – to underline the country’s place at the heart of Islam.

In About Time, Rooney predicts that clocks will always be used ‘in governing people, in securing power and in controlling human behaviour’. In the late 19th century, imperial Britain contrived to establish its supremacy by ensuring that the zero line of longitude – the origin of universal time – ran