Episode 17
Your Majesty.
The Haedong Water Clock cannot be our official clock.
Why do you say that?
It follows the design of Su Song's water clock.
It is not accurate enough.
To prevent our current problems from reoccurring in the future,
we must make a new clock in a new way.
Your Majesty.
I observed the Haedong Water Clock operating for many days.
It has never been inaccurate, not even once.
It is missing the armillary sphere which Su Song's water clock has,
so it is not completed yet.
However, it tells the time accurately.
(King Sejong: The fourth king of Joseon)
Cogwheels and gears are what move Su Song's water clock.
Cogwheels and gears are made of wood, so they wear out easily.
They can be replaced frequently, but if it's not done at the right time,
the clock will become inaccurate.
Your Majesty. The person who made the clock would be...
the best person to tell whether it is accurate or not.
Officer Jang, who is in charge of the water clock,
is saying that the Haedong Water Clock is accurate.
I trust that we should believe what he is telling us.
Your Majesty.
Sir Jang is saying that he has an idea.
How about we listen to it?
We should do that.
Sir Jang.
His Majesty is waiting for your answer.
Yes, well...
I apologise, but right now,
I don't have anything to tell you.
How brazen!
Your Majesty.
According to Lee Sun Ji, who saw the Haedong Water Clock,
the clock is more than good enough to become the clock of Joseon.
Hence, please end this discussion,
and bring the Haedong Water Clock to the Palace.
While Officer Jang works on making the armillary sphere spin,
you, my ministers, should observe...
the Haedong Water Clock whenever your time allows.
We will discuss this matter again after observing the clock.
Understood, Your Majesty.
I'm pleased to see you.
It looks just like the water clock we saw in Beijing.
I'm impressed.
You made this by yourself.
Now, make the armillary sphere spin...
so that this Haedong Water Clock can become the clock of Joseon.
What you just said.
Do you really mean it?
Hee Je. This is about the advancement of Joseon's science.
I would not be biased...
or take sides between you and Yeong Sil.
It is because the both of you are equally important.
You two are both irreplaceable talents.
If both of your ideas succeed, Joseon will flourish twice more.
Why would I neglect or undermine your talents and skills?
Finally, we have a minister visiting from the court.
I heard that ministers would be visiting to see this,
but no one has come yet.
I am glad that you are here to see this clock.
I know that Officer Jang has been waiting.
None of the ministers have gone to observe the the Haedong Water Clock?
That is correct, Your Majesty.
Did I have to give them a command to go and see the clock?
I was hoping that they would voluntarily go and observe it.
Your Majesty.
So you saw it.
Did the Haedong Water Clock impress you?
Yes, Your Majesty.
I shall go and see the Haedong Water Clock myself.
I should praise Officer Jang for all of his hard work.
Yes, Your Majesty. That would greatly encourage Officer Jang.
I am sure that Yeong Sil...
has also been working on making something.
Yes.
I agree with you.
Otherwise, he wouldn't have mentioned using "a new method".
When the right time comes,
Yeong Sil will show us.
Let's be patient and wait for that moment.
What would Yeong Sil show us?
Doesn't it intrigue you?
This should go here.
If they're going to read these books,
they should put them away properly after reading them.
Why are all these almanacs here?
Wait a minute.
I'm the Assistant Officer of Astrology.
I shouldn't be organising books here.
I should tell all of them to gather and...
Yeong... Yeong...
Yeong... Yeong Sil.
No... Sir Jang.
Have you been keeping well?
Yes.
Yes. Well... I've been...
You have been...
keeping well yourself too, right?
I missed you.
Me, too.
I missed you, too.
I had many dreams about you as well.
I knew that you'd return gloriously like this.
My readings predicted so.
This is the first time...
that we're sitting together after you returned.
When you were injured,
I went to see you briefly.
Yes.
I heard it from the Princess.
You got beaten up because you spared me my life,
so I was very worried.
I'm glad to see you recovered and well.
You probably wanted to kill me. How did you suppress the urge?
You wandered around because you couldn't come back to Hanyang.
I am sure the thought crossed your mind.
You probably hated my guts.
I forgot everything, my lord.
The King has...
worked hard so that Joseon can make its own astronomical observations.
Now, we can freely discuss astronomy and make clocks.
Thinking that my world has arrived,
I was excited for a brief moment.
But you came back.
The King thought that you were dead.
But it is almost as if he worked so hard because...
he knew that you'd return like this.
None of it was for me. The King did it for Joseon.
You are very much aware of it, my lord.
Why did you come to see me?
Well...
You said that you must make the rings...
in the armillary sphere spin to complete the Haedong Water Clock.
By any chance,
are you trying to make the rings spin separately?
Why are you asking?
You won't be able to make the rings spin separately.
Within the structure of Su Song's water clock, it'd be impossible.
What did you just say?
I know what you're doing.
You're trying to impede because you're jealous that I might make...
the armillary sphere rings spin, which you couldn't do in Ming.
My lord, please calm down and listen to me.
Shut your mouth!
I cannot listen to your impudent talk.
If we can measure their weight accurately,
we should be able to make the rings spin separately, right?
I hope that is the case.
I think they will spin.
You're here.
We're measuring the weight of the rings now.
They won't spin well if they are too heavy.
Yeong Sil said that...
this armillary sphere won't spin.
What a strange man.
I heard Sir Jang said that...
a new method must be used to make clocks and that...
he criticised the Haedong Water Clock.
Because of what Sir Jang said,
everyone was guessing that he'd be making a clock now.
But according to the rumours, that is not what he is doing.
I heard that he isn't working on anything at the moment.
That makes no sense.
He can't be doing nothing when he brought up using a new method.
What are you working on now,
Jang Yeong Sil?
Well...
If Sir Jang said that the armillary sphere won't spin,
there must be a reason.
- So Officer Jang, you should... - Your Highness.
I will be back shortly.
Do you want to get beaten up again?
I can't believe that you're visiting me like this.
What is this now?
It is a small gift from me, who is your childhood friend.
I hope it can be put to good use.
I need to know why you're giving it to me...
to decide whether to put it to good use or dump it.
I think that Yeong Sil is...
making a water clock in secret.
Find out where he is making the water clock...
and tell me.
You must not...
You must not destroy or set the place on fire before I arrive.
Promise me now.
You're too late.
Someone already gave me...
a lot more silver coins and told me to burn Yeong Sil's water clock.
He also wanted to destroy your Haedong Water Clock.
I...
told him that you're just making these things as a hobby.
Is it Lord Ha Yeon?
No.
Then...
is it Jeong Chi Soo's group?
Is that really important to you?
Right.
He said this, too.
"Jang Hee Je's knowledge in science is not that threatening."
"People have told me that Jang Hee Je is..."
"not as wise and bright as that servant, Yeong Sil."
Why do you make your life so much harder than it has to be?
Just focus on studying Neo-Confucianism...
and use your studious brain to become a prime minister.
I'm giving you this advice...
as your caring childhood friend.
I need to burn Yeong Sil's new water clock to ashes...
for the silver coins he paid me.
After that,
I will kill Yeong Sil.
Tell me.
Why are you...
so obsessed with killing Yeong Sil?
Do you really not know?
I didn't hate him from the get-go.
When we were young, you taught me...
how to tease and make fun of servants, including Yeong Sil.
You've grown into an indecisive, precarious and confused nobleman.
But I've grown...
to despise every single thing that Jang Yeong Sil does.
And now,
he's like a fishbone in my throat.
That is how it all began,
but we've come way too far to return.
If people hear this,
they will think it is ridiculous.
But things cannot go back to how they were.
They absolutely can't.
Isn't it hilarious?
The weather is very cold these days.
I put plenty of cotton wool, so it will keep you warm.
No matter what you do, don't push yourself too hard.
So you're saying that Yeong Sil was here last night,
and he wasn't working on anything.
No, no.
There is no way.
This isn't the place.
You've been fooled by Yeong Sil.
This is not where he is making his clock!
Go and find out where it is!
Jang Yeong Sil.
How dare he deceive me!
Fire now!
Now, 1, 2!
Is everything going well?
- Yes, Lord! - Yes, Lord!
This is amazing.
- Ouch, it's hot! - Is it?
These cannons will be sent to the border area...
to be used for protecting the border.
I invented them.
This is truly impressive.
Is there anything that you can't do, my lord?
You're a civil officer as well as a military officer.
You also made the metal printing type.
You're even making cannons now.
Yes.
That is why the King puts so much on my plate.
I'm worried about being sent to the border area...
as a military official at this old age.
I'm noticing more strands of white hair these days.
You always had white hair.
I have a lot more of them now.
I see. Okay, okay.
Yeong Sil.
I brought you here because...
I wanted to show you that we need an accurate clock...
for these cannons to function properly.
Well, what do cannons have anything to do with clocks?
To fight enemies,
it is crucial that our soldiers move at promised times.
If they have clocks that tell the time differently,
they will not be able to fight effectively.
If I end up going to the border area...
to fight the Jurchens,
I will definitely need an accurate clock.
My goodness.
If you have to go to the border area at that age,
you will end up with even more strands of white hair.
I see.
In addition to helping the people's daily lives,
clocks can also be used to aid the military and national defence.
This one must be convenient to use.
That is correct.
It would be truly amazing...
if the clock could be used even during riding a horse.
I see. I will make sure to make the clock you need.
Yeong Sil. The King is...
also thinking that you're probably working on...
making a water clock using a new method at the moment.
I knew that you'd know.
You have to work on making the self-striking clock in secret...
because I couldn't protect you.
I am sorry.
I will show it to you when it is completed.
Please give me some time.
Of course.
The day that I can show you everything will arrive soon.
For now, please think that I'm not working on anything...
and pretend that you know nothing.
My lord. You know that I excel in two things, enduring whips...
and the studies of science.
Now, I can add one more thing to the list.
What?
What is it?
I can tell right away if someone is shadowing me.
It is almost as if I have eyes on the back of my head.
If I think that it is someone trying to harm me,
I can give him the slip easily,
so please don't worry.
Sir Lee!
Do you know me?
How would I not know you?
I pursue astronomy as well.
I've seen you from afar.
Everyone said that you're a maths genius.
I heard you calculated the altitude of the North Pole correctly.
"Sir Lee might come to see me one day."
I've been thinking about the possibility.
And you're really here.
I, too, have been very curious about what kind of person you are.
So you predicted that I'd come to see you?
I guess we were on the same wavelength.
I heard you're helping Officer Jang.
I am.
He came to me one day to invite me to work with him.
He's a great man from whom I can learn a lot from.
- He is. - I heard that...
you said the armillary sphere won't spin.
"How would he know?"
"He seems to be doing nothing himself."
But you aren't...
the kind of person who wouldn't do anything.
I wanted to see what you had hidden.
I'm not saying I'm here to spy on you.
I'm just...
curious.
And I ended up here.
Are the rings...
spinning separately?
No.
To be honest,
the more I study it, the more I think they won't.
I don't think...
the gears alone will provide enough power for that.
I haven't made one myself,
but whichever way I think,
there is no way to make the rings turn separately.
I know nothing about machinery.
I'm only good at maths.
Do you really want to know...
what I am making?
Pardon?
Of course I am.
Why else would I have...
followed you here?
I'll show it to you.
Will you really?
Come in.
What on earth is this?
Is this a clock?
Hello, Sir.
Who is he?
This man is...
someone who can help us.
What are all these?
- They're... - No, no.
Don't tell me.
Let me guess.
Where did you find this fool?
I don't know.
Very little separates a genius from a fool.
This must be what makes the dolls beat the drum and gong,
but I don't see any wheels.
Where did you hide them?
You said you'd show me.
What you see is what there is.
It can't be.
There are no cogwheels or gears.
What are these?
How can you make a clock...
with these toys?
Where is the power source?
You're holding it.
What?
These iron balls?
How can iron balls power...
Do...
these balls...
fall down those pipes,
hit the spoons,
and that's...
what makes...
the dolls move?
You do have a quick mind.
That's impossible.
You used brass because...
Cogwheels wear away,
which is why they aren't suitable pieces for a clock.
Pieces of the Haedong Water Clock will wear away,
making it tell the wrong time.
Is that why instead of wood...
Yes.
The important parts...
are all made of brass.
Even then,
how can this small ball create enough power?
That is the core principle behind my new clock.
Watch very carefully...
and see how the ball does the job.
- Kang Chun. - Yes?
Send a ball down...
and ring the bell.
Okay.
The bell.
It rang.
Roll another one.
The ball falls down the pipe and tilts a spoon...
that moves the doll's arm to make it ring the bell.
The drum and gong must tell...
the hour and minutes.
Correct.
Will you see it work?
One drum and one gong for 7pm.
Okay.
One drum and two gongs.
(One drum, two gongs is 7:24pm)
No drumbeat.
Just two gongs.
Then 24 minutes later...
Still no drumbeat. Just three gongs.
Then...
at the following hour,
will there be 2 drumbeats and 1 gong?
At 11pm, it would ring 3 drumbeats and 1 gong.
- Right? - Yes.
The drum beats only once per cycle.
The gong signals the following four intervals...
by ringing 2, 3, 4 and 5 times.
I see.
The ball signalling the start of a cycle...
does two things.
It rings the drum and the gong at the same time.
Oh, I see.
It touches this spoon to beat the drum,
then it passes through here to enter the gong pipe...
and touches this spoon to ring the gong once.
Then it stops here.
Then at the start of the second cycle,
it touches two spoons in turn to...
beat the drum twice.
Then it goes to the right to touch the spoon...
to ring the gong once,
then it stops.
Yes.
How did you...
make it so that...
it beats the drum...
multiples times?
Would you like to figure it out?
No.
I helped Officer Jang make the Haedong Water Clock,
but I really don't get this.
How does it work?
What makes some balls go to the right...
and some go straight down?
It doesn't make sense.
It's magic.
It's not magic.
The secret is in...
the ball's sacrifice.
"Sacrifice"?
Yes.
The iron ball touches the spoon, goes to the right, then stops here.
At the same time, it opens up another route.
The next iron ball is able to pass through,
triggering two spoons to make the doll beat the drum twice.
Once it does that, it locks itself in the pipe,
opening up the next section.
Then on the second, third, fourth and fifth intervals of each cycle,
the ball goes straight into the pipe under the doll that rings the gong.
And using the same principle, it sacrifices itself so...
the next ball...
can do its duty.
Yes. You got it.
It's amazing.
Instead of using dozens of dolls as Su Song did on his clock,
or Officer Jang on his,
you focused on automated time alerts.
Without wheels or gears.
Just with the force of these rolling balls.
I can't believe you made a clock that works with iron balls.
I see 12 dolls which means...
you divided a day into 12.
How does this work?
Don't tell me...
this uses iron balls, too.
Of course it does.
This wooden beam is the secret.
The ball that triggered the bell hits this beam,
and pushes up...
the figure for that hour.
That tells you what hour it is.
I see.
Now I get that.
But how do you make it push up the figure next to it?
That's where I'm stuck.
But I will figure it out soon.
Show it to me then.
This is amazing already.
This...
This is just impossible.
But I'm looking at a working model.
How come...
Thank you...
for letting me see this.
Where did you get the idea?
Two scholars who worked with me at the observatory,
Park Hyo Won and Lim Myung Deok...
were killed by those who were against what we did.
They died...
and I lived.
I wandered,
and then decided to die myself,
so I laid beneath a tree.
A persimmon hit me on the forehead.
That instant,
I gave up wanting to die.
All I could think about was the force that...
made that fruit fall.
Since there is no need to create power,
I thought this clock...
wouldn't cause any strife.
All I can say is that...
you were born to do this.
If you had this idea when you were contemplating death...
(Volume: 3.05cm³, weight: 16g)
(Volume: 65.41cm³, weight: 534g)
I think...
the volume and weight of each ball must be important.
I believe...
my two dead colleagues sent you to help me.
I asked them every day in my mind...
how big and heavy the balls should be.
And what they should be made of so that they don't wear out easily...
and make my clock accurate.
That is when you appeared.
- Will you... - I'll calculate...
the size of the balls.
I will do it.
Please let me.
Yeong Sil.
You have more people to look after now, don't you?
I think I should make...
many more jackets, then.
900 and...
70...
The width is...
What if I'm actually a traitor...
and I end up revealing...
where your secret workshop is?
Why did you bring me here?
I know you wouldn't do such a thing.
You will follow in Lim and Park's footsteps and...
become a great scholar for Joseon.
I let you into my workshop because I wanted you...
to see something new.
I think that those...
who love and appreciate...
maths and science are pure and passionate inside.
If Officer Jang wishes to see this, bring him along.
You were impressed when you saw my water clock.
I believe...
Officer Jang...
will appreciate this too.
And it will make him happy.
Right.
I have a question for you.
The force that works on a moving object.
Can it be determined?
Lim and Park said that...
we can only calculate the average speed of a planet...
and not the exact number.
The average speed.
Yes.
This is it.
Here you go.
Officer Jang.
The armillary sphere's rings cannot spin separately.
Why not?
You said it was mathematically possible.
We confirmed the calculations.
The problem is that...
these rings continue to spin without stopping.
We calculated that we need 1.62 litres of water to work...
the celestial globe and chimes,
and 0.18 litres...
to spin the rings on the armillary sphere.
Yes.
We said we could even out the force to make the rest work.
It looks right on paper,
but not in reality.
Why not? Explain in detail.
Because the 1.62 litres we came up with...
is the average amount of water needed...
to spin the rings.
We need an accurate calculation for each of the rings,
not an average number for all of them as a whole.
But what we need is almost impossible to calculate.
It's like calculating how planets move in the sky.
However detailed the calculation is,
any number you get...
is just the average of the movement of each planet.
Are you saying there's a limit to describing nature with numbers?
It's possible to use numbers, but nothing ever stops,
so you can't put one absolute number on everything.
So mathematically it must work,
but it won't in reality.
But that is natural?
Must the rings spin separately?
I think a clock should just be able to tell the time.
Yours works perfectly.
You can use a cogwheel to make the rings spin together.
That is not my goal.
The clock I want to make...
is the one with rings that spin separately!
Sir Jang knew that many issues that can't be solved with maths...
would occur with this project.
That's why...
he said the rings wouldn't spin separately.
I actually met him.
You met Yeong Sil?
Yes.
I saw the incredible clock he made.
He took you to...
where he's making a water clock?
He said I could come back with you.
With me?
Yes.
What for?
He's making it in secret.
He said the clock would make you happy.
I urge you to go.
Sir Jang's clock...
is so innovative, there never has been one like it.
How?
How is it innovative?
He uses free fall.
Do you expect me to cheer when I see the clock you made?
You never stop taunting me,
Yeong Sil.
Go and have a look at his clock.
See how it works,
and what it looks like.
I told you exactly how I feel about Yeong Sil.
Hearing you say that...
hurts my feelings.
You said you would tell me your wish.
I have one also.
It is for you and Yeong Sil...
to work together...
to create a better Joseon.
When I heard that Yeong Sil had died when the observatory burned,
it felt as if the possibility of realising my dream was crushed.
Now he's back,
and he has become a great man who does not need anyone's pity.
It saddened me,
but I was also pleased that he had returned.
Even more so because he had grown since.
You are the one who let him live.
I had to return the favour.
You shine bright, and you will light the future of Joseon.
I'm sad to see the clouds around you.
I wanted to help clear the clouds.
All that is left...
is for you to free yourself from the shadow of Yeong Sil.
I see your light,
but you do not.
I hope that one day you will see it.
I'm sure that...
our King wishes that from you, too.
I'm glad you're here.
This is the map to Sir Jang's Dongdaemun workshop.
You will see...
some amazing things there.
Very well.
Officer Jang.
What has you so focused?
It's nothing.
Come with me to a village in Namyang.
I found out where Yeong Sil used to live.
I might be able to find his secret workshop.
I lost interest in him.
You can go alone.
Are you...
pretending to be a gentleman now?
Bye.
Oh dear.
Yeong Sil.
Are you going somewhere?
To the workshop.
At this time of night?
What's this?
What have you made?
Free fall.
What is falling?
I can't tell.
There's no waterwheel,
cogwheels or gears.
He didn't take anything from Su Song's design.
How is this thing powered,
and what makes the dolls ring the bell and gong?
How does this work?
These iron balls?
That's impossible.
Why am I hiding?
(Jang Yeong Sil)
Sir.
Take Hak Joo.
I shall inform the authorities of your crime.
I'm sorry.
Forgive your cowardly master.
Officer Jang left.
You can stay with me until...
your master returns.
How about we call your new clock "Jagyeokru"?
What are you doing?
People keep touching the centrepiece.
The public cannot be allowed to have a clock.
Time belongs to the King.