Witches and the First Army had been gone for four days. According to the plan, they should arrive at the outskirts of Silverlight City tomorrow afternoon.

With Honey-equipped messenger pigeons, Roland received letters from the team every day, from Iron Axe, Anna, and Nightingale. Although not as fast as a mobile phone, it was basically equivalent to a wireless telegraph. If there were several times more messenger pigeons on this route, with birds constantly shuttling between the two places, it might even be possible to simulate the effect of text messaging.

With Nightingale absent, the Chief Knight had taken over the responsibility of guarding the castle. However, what puzzled Roland was that Carter had been looking cheerful these days, as if something particularly happy had happened. Was returning to his original job and being responsible for protecting him so gratifying?

He shook his head and focused his attention on the report from Minister of Construction, Karl van Bate.

With the assistance of the Sleeping Island witches, the construction projects in Border Town had progressed rapidly over the past month.

First, the steel bridge over the Redwater River was successfully completed. Compared to traditional stone and wooden bridges, the steel bridge body could be prefabricated and then hoisted as a whole. In addition, the two floating islands raised by Lian in the river further simplified the construction difficulty, shortening the main bridge construction period to an astonishing one month.

Although from the perspective of later generations, it was short and narrow, with an overly simple structure, very low load capacity, and purely a waste of materials, it was still considered a magnificent super bridge in this era. It was over one hundred meters long, with a straight bridge deck that could accommodate two carriages side by side, and the lower part could also accommodate inland river sailing boats. None of these points could be achieved by heavy stone bridges.

Secondly, Lian's new city wall had also been completed. This city wall, made entirely of earth, had more than doubled the area of the town. If a city were to be built in the future, the original town would become a veritable "inner city." However, Roland preferred the terms "first ring" and "second ring." Perhaps one day, this place could be expanded into a giant city with seven rings, officially crowned with the name of imperial capital.

Finally, there was the construction of the Kingdom Avenue. Some of the foothills that stretched down from the Impassable Mountain Range were leveled by Lian, allowing the road to pass straight through, greatly reducing the overall construction period.

"Your Highness, what is your next construction plan for Lian?" Karl asked after reporting on the progress of each project.

It was clear that he was full of envy for the ability to transform terrain, and was only short of directly asking to include her in the Ministry of Construction and appoint her as the deputy minister.

"Hmm..." Roland was also thinking about this issue. He had three major transformation projects to be implemented next.

The first was the estuary project: finding a low gap in the southern mountain range and then sinking it into a road that could access the shallows. This required Lian's ability to achieve. Once the transformation was completed, the Western Territory would have a harbor facing the sea.

The second was residential expansion: Although the City Hall had invested a lot of manpower and financial resources to speed up the construction of residential areas, nearly three thousand people might still not be able to live in warm brick houses when winter came. The wooden sheds and simple shelters currently built could not meet the needs for cold protection at all, so he needed a batch of cave dwellings with thick walls and heated brick beds to solve this problem.

The last point was to build a dock: To produce shallow-water heavy gunboats, he had to first lay out a spacious dock without affecting the passage of the Redwater River. Roland planned to lower a section of the river bank on the west side of the town to form a dry dock, and install lifting gates on the side close to the Redwater River to control water retention and drainage. The scale of the earthwork project was huge, and it also had to rely on Lian's ability to complete.

After considering for a moment, he finally decided to put residential expansion first. Since he had brought the Eastern Territory refugees to Border Town, he had to be responsible for their food, clothing, shelter, and transportation. Freezing and starving to death would not only be a loss to the Western Territory, but also reduce the sense of belonging of the people to this place.

"Then where will this temporary residence be built?" Karl asked.

"Let's put it in the current serf shantytown," Roland said, glancing at the map. "Away from the city wall defense line, and with the Impassable Mountains to shelter from the wind."

After the Minister of Construction took his leave, he was about to lean back in his chair for a nap when Kaimo Strale came to the door again.

"Your Highness, the large-scale acid production method you requested has been successfully developed."

This sentence immediately dispelled Roland's sleepiness. He stood up from his desk in surprise and said, "Really? Take me to see it quickly."

A group of people came to the laboratory by the Redwater River, where several gray-white jars and a furnace kiln had been set up next to Laboratory No. 5. Each jar was about two people tall, with pipes connected to the top. The regular and smooth appearance was obviously cut out by Anna.

"Greetings to you, Your Highness," a young man bowed to Roland.

"You are Chames, right?" Although he had known for a long time that Kaimo had dug up a group of alchemy apprentices from Redwater City and had also won over an outstanding alchemist, today was the first time he had seen the other party's appearance.

"You actually remember my name," Chames said in surprise.

"Mr. Kaimo has mentioned you many times," Roland patted him on the shoulder to show encouragement. "Good job." Then he looked at the Chief Alchemist, "How is this thing made of acid?"

Kaimo stroked his beard and smiled, "Its successful development is entirely based on the reaction formulas in Elementary Chemistry. Look at that furnace, the purified sulfur will be burned in the kiln, and the generated gas will be further heated and sent into the lead tank."

"These devices are all made of lead?"

"That's right, only lead can resist the corrosion of acid." Kaimo nodded. "The lead pipe at the top of the tank continuously sprinkles nitric sulfuric acid. Under the scorching sulfur dioxide gas, nitric acid is decomposed into nitrogen oxides, and finally reacts with water and sulfur dioxide to form sulfuric acid solution, which flows out from the hole at the bottom. The ingenuity of this reaction is that nitrogen oxides only play the role of transferring oxygen and are not consumed themselves. Therefore, the amount of nitric acid used is not large, and once the reaction starts, it can continue indefinitely!"

"What is its output?" Roland asked excitedly, patting the lead tank. Large-scale acid production is the prerequisite for mass production of smokeless gunpowder. If this problem can be solved, the ammunition for the new generation of repeating rifles and cannons will be hopeful.

"This is the fourth device I have tried to make, and the output in one day is roughly equivalent to the output of the laboratory's dry distillation method in one week." The Chief Alchemist said proudly, "Because there are experimental factors, its volume is not very large. If a larger capacity lead tank can be built, the output can be further increased."

"This is really good news," Roland said with a smile, "When Ms. Anna returns, you will immediately start building a larger-scale acid production device. In addition, if there is not enough lead, you can use iron instead. Ms. Soroya's coating can protect ironware from acid corrosion."

Kaimo nodded in agreement, but his next sentence froze the prince's smile on his face.

"Now that the large-scale acid production method has been successful, and all five laboratories are full of apprentices, Your Highness, can you reward me with the Intermediate Chemistry you promised?"