The person who called out to me was Mr. Roar Eisker, the head of the Aeronautical Research Laboratory, who had arrived at the cafeteria earlier.
"Mr. Jin, it's been a while."
"Hello. Ciel, right? And this is Mr. Tyner.
It's an honor to be remembered.
There were also Ciel Azure, Tyner Vito, and other members of the Aeronautical Institute, so we were a big group.
Reiko and Chel are not seated, but are standing diagonally behind Jin and Arnold, respectively.
"...... But, Arnold, you can eat, can't you? ......"
"Yes, I have a good sense of taste. However, since they don't need to be digested and absorbed, they are broken down into atoms or agglomerated in the body for other uses."
"What other uses?"
Apparently interested, Katya asks Arnold a number of questions.
"For example, sugar can be extracted and agglomerated to make glacial sugar, and salt can be extracted to make salt..."
"Oh, that's right."
"......It really is a well-made body. ......"
Meanwhile, Jin was being questioned by a member of the .
"I heard in passing that you have discovered a new type of propulsion system that has never been seen before?
As one would expect from the head of the Aeronautical Research Laboratory, Rohr-Eisker had a quick ear.
Since there should be an official announcement on the magic rocket engine shortly, he thought it would be a good idea to at least affirm it,
"That's right. I think it will be officially announced soon.
Jin only answered, "Yes, I think it will be officially announced soon.
* * * * * * * * * *
After lunch, Jin and Arnold went back to the .
"What are you developing now?
to which Groma replied, "An underwater Gorgon.
"An underwater golem.
"Oh?"
"Of course, a normal golem can act underwater, but the one we are developing has a body that can float on water like a human being.
I see.
"Shipping will continue to develop in the future. This will lead to accidents at sea, so rescue teams will have to be dispatched. That's what this golem is for.
"So that's how it is. Peaceful use, that's good.
Jin was all for it.
Seeing Jin like this, Eira asked him for advice.
"The only problem is, how do we get it to float? That's what Groma and I are discussing.
Eira explained that the discussion was whether the golem could be made to have a specific gravity of about 1, which would make it about the same as water, and thus float, or whether it could be made sturdier and heavier and use a propulsion system such as the <> to make it float.
The one with a specific gravity of 1 does not need to do anything special in order to <>, but it requires the use of lighter materials, which may raise concerns about its strength.
The one using a propulsor has the disadvantage that it will sink if the propulsor malfunctions, but there are few restrictions on materials.
As for the materials, it is common that they must be resistant to seawater.
"I want to make it sturdy, because it will be more powerful for rescuing people," he said.
"That's what I'm thinking, isn't it?"
Eira prefers to use propulsion to float.
"But as an engineer, I'd like to make one with a specific gravity of 1.
"But as an engineer, I'd like to make one with a specific gravity of 1, wouldn't you, Mr. Jin?
Groma is of the opinion that the specific gravity should be 1 without using extra propulsion.
"Well, which side are you on, Jin?"
Jin answers with a laugh.
"I want to make something that satisfies both sides. Even Eira doesn't want to make it too heavy, does she?
"That's right.
Then, it's not a bad idea to pursue both strength and lightness.
In this case, it is not good if the specific gravity is, for example, 1.1.
It has to be able to float in water without using any auxiliary means.
"Considering the power, we really want to use metal for the skeleton. That would inevitably make it heavier."
That's true.
"If we use metal for the exterior as well, the specific gravity will be about 2, no matter how we try to make it work.
I've thought about it, Eira said.
Have you tried life vests?
"Sort of. The human life vests were not enough."
There was also the possibility of adding external equipment such as <<>, but Eira said that the human version was not buoyant enough at all.
"You know? It's difficult to do.
"The only thing left is special materials. ......
It was thought that using materials that could be strengthened by magic power would make it light and strong.
But...
"Mr. Jin, that's a little tough too.
Ka-CHEER said, "That's not good enough.
"It has to be able to be mass-produced. ......
"That's tough."
Materials that can be strengthened with magic power are usually expensive.
Right? That's why we're discussing it. What's your opinion on ......, Jin?"
"Hmmm... ......"
After thinking for a moment. Jin's answer is .......
"We should develop inexpensive materials that can be strengthened by magic power.
He said, "What?
"What?
"Hmmm... ......"
"Oh, I see. ......"
Eira, Gromma, and Cachea each expressed their thoughts in short sentences.
"The only thing that might hold us back is the <>. What about you?"
"We've been given a deadline of six months, and we have less than four months left.
"I see. I can spend two months developing ...... materials and still make change."
Jin muttered in response to the information from Katya,
"Only Jin-san can say that we can afford such a schedule.
Jin was told, "Only Jin-san can say that he can afford such a schedule.
Then Arnold joined the meeting.
"What? A cheap material that can be strengthened with magic power? If you don't mind if the degree of enhancement is low, I have it.
"What?"
During wartime, shortages of supplies were a common occurrence.
So, what kind of material is it?
Stone.
"What?"
Corundum, to be precise.
"I see."
Stones...... minerals are < and are also important for their <. In other words, .
Diamond has a Mohs hardness of 10, which is the highest in terms of , but it has a surface that is prone to cracking, or , and its < is slightly lower.
<> is <(including ruby and sapphire) and .
The Mohs hardness of jade is 6.5 to 7, while that of corundum is 9.
In other words, corundum is superior to jade in terms of .
"Corundum is dinner ...... No, I'm sure they got quite a bit of it in what is now the Kingdom of Celuloa, so we just have to magically process it."
"That was helpful! Thank you, Mr. Arnold!
"Thank you, Mr. Arnold, for the information.
"Thank you for the tip, Arnold."
Cachea, Gromma, Eira and the others expressed their gratitude in their own words.