The Clock of Flowing Time
Don't you know you can actually see time, well at least at the Europa Center in Berlin thanks to Frenchman Bernard Gitton, who designed and built the Uhr der fließenden Zeit or 'Clock of Flowing Time' in 1982. The 13m high clock stretched across three whole floors, giving as face to time with the help of liquid in 12 large and 30 oblate small glass spheres.
The small spheres show the minutes. Each of them fills within two minutes, meaning that by the time all 30 have been filled a complete hour has passed. Past hours remain visible by counting the number of large spheres, which are filled. If ten large spheres and 15 small spheres are filled, then the time is 10.30 am or 10.30 pm, depending on whether it is before or after midday.
If 60 minutes are up so that 30 of the small spheres are filled, then their contents flows into the corresponding large sphere which represents the hour and the cycle starts again with the small spheres. At 1.00 am and 1.00 pm the entire system, except for the current hour sphere, is emptied and the cycle for the complete clock and the large sphere starts again. The flow of the neon green liquid inside the clock is controlled by a violet-coloured pendulum, which is driven by the flow of water in the upper basin.