Cambridge Corpus Clock - the clock that can "eat" seconds

The Corpus Clock, also known as the Chronophage or Locust Clock, is a large, sculptural clock on the exterior of the Taylor Library at Corpus Christi College, Cambridge University, England. It is located at ground level at the junction of Bene't Street and Trumpington Street, facing King's Parade in Cambridge. The clock was designed and funded by John Taylor, an alumnus and honorary member of the college.

It was officially unveiled to the public by Cambridge physicist Stephen Hawking on September 19, 2008. Time magazine named the clock one of the best inventions of 2008.

Look

The Corpus watch with a person for size comparison
The clock's dial is a wavy, 24-karat gold-plated stainless steel disc with a diameter of approximately 1.5 meters. It has no hands or numerals, but instead displays the time through individual slits in the dial, backlit by blue LEDs. These slits are arranged in three concentric rings and indicate hours, minutes, and seconds.

 
The clock's dominant visual feature is a somber metal sculpture of an insect-like creature resembling a grasshopper. The sculpture is, in fact, the clock's escapement (see below). Taylor calls this creature the Chronophage (literally "time-eater," from the Greek χρόνος [chronos] time and εφάγον [ephagon] I ate). It moves its mouth and appears to "devour" the seconds as they pass, occasionally blinking with apparent satisfaction. The creature's constant movement produces an eerie, grinding noise befitting its function. The hour is struck by the clanking of a chain in a small wooden coffin concealed at the back of the clock.

Below the clock is a Latin inscription from the Vulgate (1 John 2:17): “mundus transit et concupiscentia eius” (“The world passes away with its desires”).

The clock is only accurate once every five minutes.[4] Otherwise, the pendulum seems to stop, and the lights may lag behind or suddenly flash faster. According to Taylor, this irregular movement reflects the “irregularity” of life.

Conceived as a public artwork, the Chronophage powerfully reminds viewers of the inevitability of time. Taylor deliberately designed it to be "frightening": "I don't really see time as an ally. It devours every minute of your life, and as soon as one is over, it's already clamoring for the next." It has been described as "hypnotically beautiful and deeply disturbing."

The clock is located in the former entrance of a bank branch built in 1866 (designed by architect Horace Francis), which originally housed the London and County Bank. Corpus redeveloped the site to improve the library for college students after NatWest's lease expired in 2005.

Clock mechanics

Simplified animation of the escapement and the second and minute discs. For clarity, each minute is divided into only 10 seconds, each six times longer than a normal second. The minute disc is folded to the right. The green lines represent slots in the rotating discs, the blue lines fixed slots.

Opened to show the inside
The Corpus Clock is a product of traditional mechanical watchmaking. It features the world's largest grasshopper escapement, a low-friction mechanism that converts the pendulum's motion into a rotary motion, while simultaneously returning to the pendulum the energy it needs to swing. The grasshopper escapement was an invention of the famous 18th-century watchmaker John Harrison, and Taylor intended the Corpus Clock to be a tribute to Harrison's work. Since "nobody knows how a grasshopper escapement works," Taylor decided to "turn the clock inside out, as it were,"[7] so that the escapement and the escape wheel it drives would become the defining feature of his clock.

The Corpus Clock's movement is purely mechanical, without any computer programming. Electricity is only needed for a motor that winds the clockwork and for the blue LEDs that glow behind the slits in the dial. The clock has many unexpected and innovative features; for example, the pendulum stops briefly at seemingly irregular intervals, and the Chronophage moves its mouth and blinks. Taylor explains this as follows:

The golden eyelids move across the eye and disappear again in the next instant; if you don't look closely, you won't even notice it… Sometimes you can even see two blinks in quick succession. The blinking action is powered by a hidden spring mechanism, controlled in the finest tradition of 17th-century London clockmakers.

The mainspring is wound in a casing visibly mounted on the large gear that protrudes prominently from the underside of the movement. As the enormous pendulum beneath the clock swings the chronograph as it rotates around the large escape wheel, each forward and backward movement is used by free-running clutches to wind the mainspring. A locking mechanism prevents overwinding of the spring while still allowing it to move freely.

Video in action: The Corpus Clock & Chronophage - Hi-Res

Source: AI, Wikipedia, YouTube