The Fountain of the Lions in the Alhambra has amazed people for centuries. It’s a beautiful, ornamental water feature sitting preeminently at the center of the now-infamous Court of the Lions. Twelve lions hold a basin, and from their mouths, water spouts into a 12-sided canal that spreads in four channels across the courtyard. Twelve is an important number in many cultures, and regularly, we encounter it in the hours of day and night. This has had people questioning if the beautiful fountain was indeed a clock.

This idea remains a hypothesis but one that has some interesting evidence supporting it, beyond just the number of lions. There is no certainty, though, that it was indeed a clock, simply because, for centuries, it has been changed and altered. From moving the basin and adding water jets to raising the whole fountain up, the water feature is not what the engineers planned in the 1300s. But if it had been a water clock, how would it have worked?

The history of the fountain

The fountain is likely to have been built between 1362 and 1391, during the reign of Nasrid Sultan Muhammad V. A crucial description of the fountain comes from a poem that is inscribed on the basin itself. Ibn Zamrak, the vizier of Muhammad V, comments that the fountain gives the illusion of the water being solid. This suggests an incredibly steady flow.

There are many videos online where the laminar flow of water looks like a solid, unmoving at least to our eyes. We need turbulences to catch the water flow. 

Granada was conquered by the Spanish in 1492, and sources from the intervening years talk about the fountain, praising its engineering marvel but focusing on different details. These include pipes that connect to the lions’ mouths from the basins, and also the acoustics and connectedness of the lions when water is not flowing.

A recently suggested piece of knowledge comes from a poem in neo-Latin that describes how closing one of the lions’ mouths will stop the flow everywhere, and how on top of the fountain there used to be an eagle. 

Islamic gardens were filled with ʿajāʾib – wonderful creations – artificial devices, often automated, that would entertain guests. Mechanical birds that make sounds or move thanks to the flow of water, for example

Water clocks were reported in the city of Toledo, conquered by the Christians in 1085, but were quickly dismantled by the new ruler to try and work out how they worked. Without the original engineers, they couldn’t be put back together again.

How do you make a water clock?

During one of the many restorations and modifications of the Fountain of the Lions, a marble cylinder was found possessing a series of holes on two levels. When it was removed, this was connected to a series of pipes. At the time, it was described as a way to have the water flow in and out of the fountain at the same time. This could be partly the secret of its stillness.

Designing a water clock does not require 21st century knowledge. Sure, Islamic engineers have been making them for over 1,000 years, but some of the technology behind them is a millennium and a half older than that.

Let’s assume you have your 12 lions statues and your fountain. You want to start at midnight with an empty fountain, at 1 am only one lion is pouring water, at 2 am two are, and so on until noon when all 12 lions are spouting water from their respective mouths into the channel below. 

To create this effect, you need to place holes into a spiral pattern across the curved side of the basin, for example. In the first hour, the water doesn’t reach any hole so no mouths spout water, then at 1 am, the first hole is reached, and so on. The fountain needs to fill itself steadily for this to work, with an inflow that takes into account the variable outflow.

Well, the variable outflow only from the lions’ point of view. The total outflow can be made constant by channels placed in a hidden part of the fountain, similar to the marble cylinder of the Fountain of the Lions, which can regulate the flow. Crucial to regulate our water clock is also the emptying of the fountain. What you need for that is a greedy cup.

A greedy cup, also known as the Cup of Justice or the Pythagorean cup, named after its alleged inventor Pythagoras of Samos, is a cup with a hidden siphon in the middle. Fill it up to a certain point and you will be grand. The liquid fills the cup and a certain pipe in a middle structure. But if you over-fill it, the siphon in the middle will kick into play. Due to the pressure difference, it will pull in all the liquid in your cup like a straw.

Most modern American flush toilets operate by the same principle. Once the water level rises high enough, a siphon is created and the bowl is emptied. This could be used to empty a fountain of water before the cycle begins anew. Obviously, this is a simplistic sketch of how you can make a water clock work.

When it comes to the Fountain of the Lions, the water clock hypothesis is compelling, but without knowledge of the original structure of the fountain, it is currently impossible to confirm. The accounts from direct and indirect sources hint at the peculiar flowing of water and the surviving structure definitely had hidden complexity, but the true design and function are lost to time.