Jin's prototype was also a success.

The images obtained were the same as if a magic eye had been placed 20 meters away.

And it doesn't matter if there is a wall or a rock in between.

This is an unexpected effect.

Come to think of it, it's not surprising since we are using free-magic element (ether) waves instead of light waves.

"It's clairvoyance in the true sense of the word, isn't it?"

Reiko also has a function called "clairvoyance". However, it uses infrared rays, etc., and is only <>.

It is not possible to obtain such a clear image.

It would also be possible to see through it from a distance.

"You've made something amazing!

Jin thinks for a moment.

"I wonder if <> can do the same thing to us.

Jin thinks about how to prevent it.

"A barrier, after all.

Jin thought that it would be good to have a barrier that can cover the laboratory, the house, and the old lord individually, if not the whole Horai Island.

<<<>.

The old man says.

"Yes, it would be. < separately."

Jin was relieved to have one less thing to worry about, though he had to take a short detour.

"Let's combine it with Elsa's prototype.

"Yes."

With a little work, it was done.

"Okay, launch."

We're headed for the Kunlun Islands. It's about 300 kilometers away.

"Hmmm, I think we're almost there."

The most difficult thing was to adjust the direction.

Even a 0.1 degree change in the direction would result in a large error at a distance of 300 kilometers.

"Brother Jin, how close is it?

"What?　You know what trigonometric functions tell us, don't you?"

"Uh... ......"

It seems that Elsa had never used the trigonometric function even though she knew it.

"tanθ = b/a," she said.

"Oh, so a is 300 kilometers, θ is 0.1 degrees, and the error you want is b, right?"

"Yes, yes."

Jin thought about the trigonometric functions in his mind without saying it out loud.

"Then ......b = 300 x tan 0.1 degrees."

"That's right."

There was a way to have the old man calculate the trigonometric function table, but Jin was saved by the fact that it was included as an appendix at the end of the book that <> Shuki Tsetsi had brought in.

<

The old man calculated it for me by showing the formula.

"An error of just over 500 meters at 0.1 degree. ......"

Elsa looked at him with difficulty.

"I understand that my brother Jin wants the error to be zero."

"Right?"

Jin thought, "If this is extended to a distance on the scale of the universe, it may not be possible for a human to operate it.

"A special golem or a semi-automated golem?"

"Brother Jin, at any rate, I see an island that looks like Kunlun Island.

"Oh, great!"

While Jin was lost in thought for a moment, Erza had finished the adjustment.

The image was a little shaky, but it was enough for confirmation.

"Well, if we make it right, it will be practical enough.

There seemed to be no problem with the near to medium range use.

"And it also has a see-through function, or ......."

Jin named this device .

He really wanted to call it <>, but decided to hold back a little.

With this device, I can look through the walls and see what's going on in the room.

We have to be careful not to use it too much."

"Yes, I agree."

Due to moral issues, Jin and Erza have vowed to refrain from using it lightly.

Now, the main purpose is for space observation, in other words, for long- and ultra-long-range use.

"Above long-range use, we need to make a larger and more rigid structure.

Since the principle is the same, there is no problem in making it.

"Old man, please consider the strength, the size, and the range.

Jin and Erza took a rest, leaving the design to the old man.

"Father, what would you like to drink?

"Well, Citran juice.

"Yes, Citran juice. What about you, Miss Elsa?

I'll have the same.

Reiko brought them some cold Citran juice.

But we managed.

"Yes, we did."

"Father, you're the best!"

Elsa and Jin lightly touched glasses and toasted each other.

Reiko also gives her compliments.

"Now all we need is <, ...... but to be honest, it's not that important."

< has a lot of weight in his mind.

"More than that, we can make a powerful weapon by applying the <>."

"...... indeed."

"I don't intend to use it much, but I'll make one just in case something happens."

We can use attack magic instead of <.

It is also effective against the opponent at a distance where normal magic cannot reach, or through a wall.

"It would be nice if we could select the magic we want.

"Then, healing magic too."

"Yes, that's right."

As Erza said, it would be very effective if healing magic could be used at a long distance, Jin thought.

"Since we know about the healing magic, let's add this device to all the people in Horai Island.

First, Reiko, Laiko, Soleil, Luna, 5 colored golem maids, land, sea and air forces, craftsmen (Smith), undersea forces, space forces .......

And even larger ones for aircraft and ships.

"I know it's a lot of work, but please."

Craftsman Smith is very busy.

In this way, the war potential of Horai Island was further increased.