Time Machine at Letná

A kinetic object in Letná Park, which symbolically measures time. It replaced the communist-era Stalin monument.

The Prague metronome, named by its creator the Time Machine, is a 25-metre-high kinetic object from the workshop of sculptor Vratislav Karel Novák. The Time Machine rises above the Čech Bridge at Letná, where in the Communist era once stood a monumental sculptural group led by Stalin, popularly nicknamed the Meat Queue" After Stalin's death, Khrushchev issued an order to blow up the sculpture as part of the so-called de-Stalinization of the Soviet Union. Indeed the location of the metronome at the site of the former Stalin monument symbolises the relentless passage of time and is a cautionary reminder of the Communist past..

In 2003 the Metronome was also used to promote a referendum on the accession of the Czech Republic to the European Union, when the pendulum swung between YES and NO. In 2009, it symbolically measured the Czech presidency of the EU.

It was nicknamed the Metronome due to its external similarity to a Maelzel metronome, but mechanically it is completely different. Along with the pendulum the entire object weighs 7 tons. The pendulum with a two-ton balance reaches a 60° swing. The Metronome was made by the firm ČKD Racionalizace and took its place as a temporary object on the occasion of the General Czechoslovak Exhibition in 1991. Due to the disrupted structural stability of the site after the Stalin monument was blown up, it was installed by a means of a helicopter rather than a crane.

From time to time the Time Machine malfunctions and must be stopped in order to make repairs. The largest reconstruction took place in 2015.