What do you get when you mix a prince-archbishop’s sense of humor with an understanding of fluid
dynamics?
In this case, very wet.
I’ve come to the Trick Fountains of Hellbrunn Palace in Salzburg to find out how Markus
Sittikus and his team of engineers were able to come up with this one-of-a-kind garden.
On first inspection it might appear like a regular garden, but then this starts happening.
Understanding how these water features works is also fundamental to understanding the science
behind how our taps work.
But to understand that we’re going to have to head into the palace.
This tank is full of water.
And its being used to supply some of the fountains in the garden.
Traditionally water would be carried up here by servants, but today a pump has been installed.
This room is about eight metres above ground level.
If you’ve ever tried to swim to the bottom of a pool, then you’ll be familiar with
how water pressure works.
As we take these balloons deeper and deeper they start to shrink as water pressure crushes
them down.
This is because there is more water pushing on the balloon.
By bringing the water higher up to begin with we have this same effect.
Lifting a tank up to eight metres gives the same pressure as swimming to the bottom of
an eight metre deep pool.
The way the top and bottom are connected doesn’t matter; the same height difference gives the
same pressure.
For every one metre of height we have, we increase water pressure by 10 kPa.
That’s why you’ll find a water tower, similar to this one, if slightly bigger and
higher up, at the tallest point of every town or city.
Letting the water free is a simple matter of pulling a lever.
This opens up a pathway inside the pipe, letting pressurised water escape with enough speed
to make a fountain.
Your tap at home operates on the same principle.
We can do a lot more with pressurised water than just spray people.
This is the Floating Crown in Midas’ Grotto.
We can consider this system as just a balance of momentum.
On its own the crown would fall to the ground; gravity is giving it downwards momentum.
We cancel it out by adding in upwards momentum as the water goes up, and taking away downwards
momentum as this same water comes back down.
The end result?
The water moves up and down but the crown stays as it is.
This is what happens if you take water engineering to its extreme.
All 160 characters in this Theatre move around because of water.
We can see how this works by going underneath the machine.
We add rotation to the system by using a water wheel.
This is connected to a series of gears.
Using a bevel gear we can change the axis of rotation.
Allowing figures to walk around.
We can induce more interesting back-and-forth movements by using a rotating beam with notches
on it being read by a tracker bar.
This is very similar to a music box or self-playing piano.
Making the characters move is a simple matter of connecting the tracker bar to the wooden
figure.
Adding to the whole scene is an actual organ- operated by water of course.
In order to find out how to use water to make music we’re going to head to the birdsong
grotto.
The sounds you’re hearing aren’t tape recordings, theres not actual birds in the
walls, its all because of some very cleaver, yet remarkably simple engineering.
We begin with a water wheel, turning from that high-pressure water we brought up to
the top of the building.
This water wheel then pumps a set of bellows which pushes air through a series of pipes.
These pipes then open and close using similar mechanism to the tracker bar from earlier.
This one looks even more like a music box.
We make the actual sounds by using a tube very similar to this.
When we blow air through it…we can produce a sound.
I’ve done it with air from my lungs, but the birdsong grotto has a dozen of these connected
to the airpipes controlled by the tracker bar.
Just like a flute, there’s a hole in the middle to give us a specific note.
By changing the length of the tube by putting it into an amount of water… we can change
the note that’s being produced.
While the Palace gardens are just for a bit of fun, the engineering going into these fountains
is the same that gives us drinking water and allows us to move heavy machinery.
We’ve also introduces some basic fluid dynamics, gears and how instruments work.
Not bad for some 400-year-old engineering.
This was such a fun video to create, thank you to everyone who helped me out, especially
Thomas and Angela for taking me behind the scenes of Hellbrunn Palace.
If you’re ever in the area, I would definitely recommend checking out this remarkable place.
Next episode as we are exploring the caves of Mars, make sure to check back here in 2
weeks or subscribe to the channel so as not to miss it.
It’s going to be an awesome episode.
Until then this has been James Dingley from the Atomic Frontier.
Keep looking up.