The Clock of Flowing Time

Art, science, and timekeeping have gone hand in hand for centuries, with beautiful clocks showing time in the most intricate manners. The Clock of Flowing Time in the Europa shopping center is one of the most unique examples of a water clock in the world.

This clock was built in 1982 after a design by Bernard Gitton managed to somehow keep time on a 12-hour cycle, showcasing the hour and minutes up to an accuracy of two minutes. One would expect this to be operated by a computer that simply pours water into the right container and pushes it out when needed. However, the only part that moves in this clock is the pendulum that pumps water up to the main reservoir. 

Instead, the entire clock is a clever play on the Pythagorean cup, which is a siphoning cup allegedly invented by Pythagoras in Greek antiquity. The concept is that a siphon is created if you pour water above the height of a pipe that bends down, and this siphon doesn’t only spill over the top but sucks out all the water. Combine this event with cleverly designed pipes that clog and pressure systems that oscillate, and you have a clock. 

Of course, making this actually work, or even following by eye how the water flows is much easier said than done, as is clear from the near-constant crowd of people looking at it.