They call it the time-eater. Tonight, a monster will begin measuring the passage of time using new and decidedly sinister technology outside one of Britain’s most prestigious colleges.

Unlike conventional timepieces, the extraordinary “Chronophage”, due to be unveiled today by Stephen Hawking at Corpus Christi College, Cambridge, does not use hands or digital numerals to show the time.

Instead, it relies on a mechanical monster – part demonic grasshopper, part locust – that rocks back and forth along a golden disc, edged like a lizard’s spine. By a complex feat of engineering, its movement triggers blue flashing lights that dart across the clockface, letting students know if they are late for a lecture.

About two metres in diameter, the clock is made from discs of stainless steel and plated with 24-carat gold. With each slackening of the monster’s jaw, and release of its claws, another second is devoured. Each new hour is signalled by the rattle of a chain on an unseen coffin to remind passers-by of their mortality.

The £1 million invention is a tribute to John Harrison, the world’s greatest clockmaker, who solved the problem of longtitude in the 18th century.

The timepiece is completely accurate only every five minutes. The rest of the time, the pendulum pauses then corrects itself as if by magic. The blue lights play optical illusions on the eye, whirring around the disc one second, then appearing to freeze the next. The effect is hypnotic.

The clock is the brainchild of John Taylor, an inventor who made his fortune developing the kettle thermostat after graduating from Corpus Christi in the 1950s. A long-time admirer of Harrison, Dr Taylor, 72, said that he wanted to make a clock that would revolutionise the art of timekeeping. So he took the so-called “grasshopper escapement”, a tiny device invented by Harrison hidden away inside 18th-century clocks, and turned it into the time-eating insect that can be seen today on the college wall. The ultimate aim, explains Dr Taylor, was to create a timepiece that kept time while, paradoxically, showing it, as they say, to be relative.

“Clocks are fixed, whereas we all know, time is fluid. It drags and it flies. Like Einstein said, an hour sitting next to a pretty girl can be like a minute, and a minute sitting on a hot stove can seem like an hour. I wanted this clock to reflect that, to play tricks with observers.” Dr Christopher de Hamel, Fellow Librarian at Corpus Christi, said: “I wanted it to be a monster, because time itself is a monster . . . It is horrendous, and horrible, and beautiful. It reminds me of the locusts from the Book of Revelations.

“It lashes its tongue, and flicks its eyes at you. It’s bonkers.”

Time is of the essence

— John Harrison (1693-1776) was a working-class Lincolnshire joiner with little formal education who solved the longitude problem that had defied astronomers and scholars for centuries

— Galileo Galilei, Jean-Dominique Cassini, Sir Isaac Newton and Edmond Halley had all failed in the task. Their mistake was to believe that the answer lay in the “clockwork” of the heavens – in mapping the stars. Instead, Harrison believed there was a mechanical answer

— After 40 years of work he proved in 1764 that a clock could be used to locate a ship’s position at sea with extraordinary accuracy

— His invention of the marine chronometer finally enabled ship navigators to establish their east-west position, or longitude, while at sea, revolutionising maritime travel

Sources: Royal Observatory & history of astronomy

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