This is Paris on the 21st of January 1910 when a flash flood brought chaos to the city. Metros were flooded flooded and buildings were destroyed but more curiously, almost all
the clocks around the city stopped at exactly 10:50 as if time itself had stopped amidst the chaos. These clocks were part of a
special network of underground pipes that used bursts of air
to synchronize time around the city. This genius system was created in 1880
by Austrian engineer Victor pop and just 5 years later, thousands of these
clocks were placed all over the city in hotels, train stations, houses, schools, and public streets. We modeled this incredible system
and the special machine at the heart of it to show you how a series of underground pipes
and mechanical clocks kept an entire city in sync. Before the invention of accurate
electrical clocks, time was hard to keep. Mechanical clocks would slowly drift out of sync leaving everyone
on slightly different times. Business meetings and train schedules were impossible since no one would arrive at the right time. In fact, the idea of there being an
exact time wasn't really a thing yet. Tower bells around the city would ring out
to let people know which hour it was but as cities became more civilized, knowing the
time to the nearest hour was no longer good enough. There needed to be a way to make sure everyone was
on the same time down to the nearest minute. The idea was to have a master clock in the center of Paris that would send out a pulse each minute to
synchronize every clock around the city. Sending the signals electronically was far too expensive so Popp decided that sending bursts of air
would be cheaper and more reliable. The clocks wouldn't have to be powered the bursts of air would simply move all the
clocks in the system at the same time. This idea had been tested out in Vienna a few years before and it clearly demonstrated that
having everyone on the same time was the way of the future. So the government of Paris gave Popp and
his team a 50-year contract to provide time to Paris. The Pneumatic Clock Company set up shop
in the center of Paris and began working on the Master Clock. This was an extremely precise
clock that could run 24/7 without going out of sync. Before we look at how this incredible machine worked, we
need to understand the general principles of mechanical clocks. In order to run without electricity, a spring
or weight was typically used to provide energy. By raising a weight, energy is
stored in the form of potential energy. When it is released, gravity pulls it down and the wheel spins. Of course, a clock that ran out after
a couple seconds would be useless so an escapement mechanism is
added to slow down the weight and create a continuous pulse. As the gear turns, the escapement rocks
back and forth like a pendulum moving the gear at constant intervals and
slowing down its release of energy. By changing the length of the pendulum, the clock
can be tuned to run faster or slower. Adding a train of high ratio gears
slows down the system even more meaning the weight can power the clock for an entire week without having to be reset. For the Paris Master Clock it was split into two separate sides. On the left was a standard pendulum clock that drove
the hour, minute, and second hands. The clock on the right was basically a timer that would control
when to release the bursts of compressed air into the network of clocks. But what kept the Master Clock in time? In the Paris Observatory there
was an another super accurate clock that was updated daily using observations of stars and planets. A timekeeper would update the master clock if necessary
using the observatory clock as a reference. In order to see the observatory
clock which was in a different part of Paris the timekeeper used AnyDesk,
which gave him remote access to the clock's time. Just kidding. This entire system wouldn't be necessary
if AnyDesk was around in 1880. AnyDesk; today's sponsor is a remote access service that allows you to control your
device from anywhere in the world. All of the animations in this video were made
on a MacBook and rendered on a PC but when I'm traveling I still need to access my PC. With AnyDesk I can send the animation files directly to my PC and hit render as if I were sitting right in front of it. With AnyDesk you can directly access and copy files to your device without having to upload
them to the cloud. They have their own special codec that transfers the video of your computer
at an extremely low bit rate, without a noticeable drop in quality. The speed is lightning fast and
it even works well with poor internet connections AnyDesk works on all platforms and best of all,
it's free to use for personal use and they also have tailormade plans for businesses. To get AnyDesk for free and support the channel
visit anydesk.com/PRIMALSPACE In order to synchronize every clock around Paris,
the master clock had to be extremely precise. Both sides of the clock worked together to
send out bursts of of air to thousands of clocks connected to the system. At the start of each minute, the left hand
clock would start counting down while the right hand clock would be locked in
place by a lever. Once the left clock reached the 60th second, a tooth at the top gear activated the lever which released the right clock and allowed its gears to start spinning. Instead of an escapement to limit the speed,
the right clock had a simple fan fly which used its own drag to slow
the gears down. This would allow the clock to run for about
20 seconds until the lever locked back in place. When the gears turned, a rod attached to
one of the main gears was activated This opened a valve that would allow
compressed air to flow into the distribution pipe. The valve would remain open for the first 20 seconds of each minute and closed for the remaining 40 seconds. This created a 20-second period every minute where air could flow to all the clocks in the network. One of the best things about this entire system was
its ability to reset itself once the weights had fallen. A thin pipe leading off from the distribution pipe fed the compressed air back into two pistons
at the side of the clock. This would raise two levers attached to both clock systems, lifting up the weights and resetting both clocks without interrupting the cycle. But where did the air go
after leaving the master clock? From there the air would split into 10 different pipes
that were each assigned to different districts around Paris. These would carry the air into iron pipes that
ran for hundreds of kilometers through the sewage and metro tunnels of Paris. As the compressed air
entered the pipes it would quickly start sending a pressure wave through the entire system, taking up
to a minute to reach some of the furthest clocks. But what actually happened when the air reached
the clock? The clocks themselves were very simple. The minute hand was connected to a gear that had
exactly 60 teeth. As the air reached the clock it entered into a bellows which would inflate and
push a rod upwards. This lifted the main lever which pushed the gear along with an articulated tooth.
On the other side another tooth would stop the gear from moving backwards. Once the bellows
fell back down the tooth would pivot and a small weight would keep it engaged with the gear.
This clever mechanism meant that a full inflation of the bellows would always push the gear forward by
exactly 1 minute. The hour hand was connected to the minute gear using a ratio of 1 to 12, meaning
that the minute hand would complete 12 rotations in the time it took the hour hand to complete one.
The great thing about the system was that it wasn't just for public street clocks or train
stations - anyone could have these clocks installed in their house for a subscription fee of just
30 cents per day in today's money. Despite being damaged in the great flood of 1910 this incredible system continued to work for almost 50 years and ended in 1927 when accurate electronic clocks were
good enough to keep time. By now these clocks are long gone, but signs of where these clocks once
stood can be found all around Paris. And now, time for the Primal space giveaway. The winner of the
previous giveaway is Ethan. Congrats! In the next video we'll be giving away another one of our
Primal Space Voyager posters. All you need to do is sign up to the link below, like the video,
and leave a comment saying what you think about this incredible clock system. Thank you very
much for watching and I'll see you in the next video.
