The boiler heating system is not a complex thing. Its essence is to heat boiling water and then transport the heat to the room through pipes, and then diffuse it through the radiator. The carrier of heat can be water or steam. Roland uses the latter because the upper limit of steam temperature is higher and it is more convenient to circulate. As long as the boiler is continuously burned, the generated steam pressure will automatically fill every corner of the pipe with small, high-temperature water droplets, and even a water pump is not needed.

Of course, steam heating is not without its drawbacks. The inside of the pipeline is always in a high-pressure environment. If the interface is not strong, it is easy to leak or even explode. As long as you touch the high-pressure steam of two or three hundred degrees, your skin will be torn apart. Therefore, the installation quality requirements are higher. Anna's black line welding can ensure the strength of the interface, and with Soroya's coating, this shortcoming can undoubtedly be minimized.

At the same time, Roland also set up an automatic pressure reducing valve on the boiler. Its mechanical principle is the same as the centrifugal governor on the steam engine. When the pressure in the furnace is too high, the high-speed rotating flywheel will lift the valve to exhaust and reduce pressure.

The last layer of insurance is located at the connection between the boiler and the two main heating pipes. He asked Anna to engrave several grooves around the copper pipe to reduce its strength, similar to a can of soda. Even if the pressure valve fails to open normally, the explosion will occur in the boiler room instead of endangering the people in the room.

When the heating system was running, the scene in the castle completely changed.

The heavy and thick winter clothes were gone, and the witches changed back to their single clothes in autumn. Looking at the colorful girls talking and laughing in front of him, Roland felt that his work motivation had invisibly increased by five percentage points.

Of course, these facilities are used for enjoyment, or rather, auxiliary equipment built to create a better working environment.

The next thing to do is an important project related to the future of the Western Territory.

That is to realize the artificial synthesis of ammonia gas, reduce the dependence on saltpeter, so as to increase the output of chemical explosives to a new height, so that it can meet the requirements of automatic firing weapons.

If this goal can be achieved before the end of winter, it will undoubtedly put a heavy chip on the planned spring offensive.

Roland called Kaimo. Suichui'er and Agatha to the office.

"How has your cooperation been these days?" he asked with a smile. One is the chief alchemist of Border Town. Apart from his infinite love for alchemy, he hardly cares about the feelings and opinions of others. The other comes from the Witch Kingdom four hundred years ago and has the pride of being a member of the highest research institution, the Secret Society. Both of them are straightforward, and putting them together is like a barrel of gunpowder that could explode at any moment. Roland often worried that they would argue, but both nitrated gunpowder and synthetic ammonia required the cooperation of both of them, so he had to ask about the situation first. If they didn't get along, he would have to mediate.

"Very good," Kaimo's first words surprised Roland slightly, "Miss Agatha's ability is of great help to chemical experiments. Now I have found the stable synthesis temperature of nitrated nitroglycerin. There is no problem with laboratory preparation, and further testing of the possibility of industrial preparation is underway... It can be said that without the ice cup, none of this would be possible. Oh, because I was too busy with work, I didn't notify you." He paused, "By the way, if you want to inquire about this, can you let me go back to the lab now? I still have a lot to do."

Uh... is that so? Roland looked at Agatha, who nodded.

"Mr. Kaimo's knowledge is indeed extraordinary, especially his understanding of elements, which is quite similar to that of the Secret Society. Our cooperation is currently very pleasant. If he were in Taqila, he would definitely be absorbed by the Union."

Could it be that straightforward people get along easier with each other? It seems that he was worried for nothing, and why is the Chief Alchemist's attitude towards the witch better than his own? It's heartbreaking... Roland muttered in his heart, then cleared his throat, "Since that's the case, I'm relieved. I called you here to give you a new research project."

Hearing the word research, Kaimo immediately became energetic, "Please tell me."

"I said before that there are many different gases in the air. Now is the time to use them." Roland roughly explained his ideas, "According to the Elementary Chemistry Records, oxygen and nitrogen account for 99% of the air. Now I need to separate these two gases for chemical production."

Kaimo pondered for a moment and replied, "You mean, use their different properties... such as different boiling points and melting points to separate them?"

"That's right," Roland nodded approvingly, "Cool the air and then heat it up. The boiling point of nitrogen is lower than that of oxygen, so it will be distilled out of the liquid first. Since this temperature is far lower than the freezing point, it is difficult to do with current conventional methods, so we must use Agatha's ability to achieve it."

"Turning air into liquid," Kaimo said, stroking his beard, "Sounds very interesting."

"If you further reduce the temperature, they can even become solids, like ice cubes," Roland said with a smile. This is definitely a scene that contemporary alchemists have never imagined. The seemingly ethereal gas can also be held in your hand - provided that you take precautions against frostbite.

Agatha asked suspiciously, "I also read some of that book, but when I froze the air, I didn't see it solidify into multiple gases."

"Because they don't produce stratification after being mixed together, it is difficult to distinguish them with the naked eye," Roland explained, "The first to be excluded is carbon dioxide. Its freezing point is relatively the highest, but the content in the air is extremely low, so you won't even notice the small particles that it solidifies out. Next are oxygen and nitrogen. They can perfectly merge and appear light blue. If they are not separated, they look like a pure substance. In fact, liquid nitrogen should be colorless."

"What should we do?"

"First prepare the fractionation vessel," the prince curled his lips, "This is a big project."

There is no doubt that Agatha alone is not enough. Glass is prone to cracking during repeated temperature changes, so the container for liquid air can only use an all-steel shell. This is not a difficult task for Anna, but the completely enclosed shell will make it impossible to observe the changes in liquid air during heating, so Sylvie's magic eye is also needed to observe the scene inside the container. Then Agatha will record the specific amount of magic consumption when liquid nitrogen boils to obtain stable production temperature parameters.

This preparation work lasted for three days.

When the container was completed, Roland personally came to the chemical laboratory to guide the first oxygen-nitrogen separation experiment in the town.