In addition, there was also the dowry left by his mother. Charles's mother came from a merchant family, and his maternal grandfather was extremely wealthy. The dowry alone included twelve storefronts located on the main street of Xianyang City, and seven estates, with annual income reaching as much as fifty to sixty thousand gold.

Even with Charles's endless daily extravagance over the years, he could not spend it all. Moreover, he was no fool and would never squander money recklessly like those prodigal sons. On the contrary, he was quite frugal with his spending. Over the years, he had also invested in some businesses, purchased several estates and shops, and actually made quite a profit. In addition, there was some gray income such as protection fees, which need not even be mentioned. With the Four Evils running rampant in the capital, naturally, there were many who knew how to read the situation and came to seek his favor. As long as he ensured the safety of their businesses, he would receive a considerable amount of tribute every year.

At this point, if Charles wanted anything, he only needed to say a few words, and someone would deliver it to him, never taking more than half a day.

As for the rules and mathematics required for making devices, Charles himself also had a foundation. His mother came from a merchant family and was highly accomplished in this area. When he was six, she forced him to memorize the entire "Nine Chapters on the Mathematical Art." Although he had neglected it somewhat over the years, he was confident in his talent in this regard and could pick it up again after reviewing for a day or two.

As for all the drawing tools needed for making devices, it was easy to collect them in the Duke of Anguo's residence. The so-called "rules" did not refer to etiquette, but rather to ancient tools for drawing circles and squares—"gui" for drawing perfect circles, "ju" for perfect squares. The study of "gui ju" was the knowledge of how to calculate and draw various shapes, which is what Westerners call geometry.

It was said that nowadays, some great masters of mathematics had even begun to use this art to study the fundamental structure of the world.

Because "Mo armor" was flourishing in the world, the techniques of the Mohist school had also become a prominent field of study. As for the doctrine of "universal love and non-aggression," no ruler would ever like it. But the arts of rules and mathematics were highly valued by the seven great empires of Central Plains, honored as the "School of Numbers," the largest branch outside of the Mohist school.

The first things Charles chose to make were the "Detailed Explanation of Device Making," which included the more difficult "Sleeve Pearl Launcher" and the "Linked Blade Box." Both could be hidden in the sleeve and, when triggered, could take a person's life.

For a beginner in device-making, these things were undoubtedly as difficult as reaching the sky. But with the financial backing of the Duke of Anguo's residence, the process was much simpler for Charles. He only needed to draw the parts, mark the dimensions, and have someone make them.

He did not want anyone in the Anguo residence to know about this, nor did he intend to reveal the complete blueprints. It was clear that the various devices in this "Detailed Explanation of Device Making" were all extraordinary and valuable, and there was no reason to let outsiders benefit. The Mohist school did have similar killing devices, but as Charles had learned before, none were as exquisitely demanding as these, and their power was likely far inferior.

So Charles first drew the parts separately and had several of his own guards take them to different Mohist workshops to place orders.

Just six days later, a "Sleeve Pearl Launcher" and a "Linked Blade Box" were both completed.

The former was shaped like a bamboo tube, containing a magazine and mechanism, and was worn under the forearm. With just a lift of the hand, one hundred and eight pellets inside could be shot out in a burst. It was easy to reload, and after use, a new magazine could be swapped in an instant. Charles, being wealthy, had prepared seven magazines for this device.

As for the "Linked Blade Box," as the name suggests, it was a box that concealed throwing knives. When triggered, it would shoot out seven flying knives in succession. According to the "Detailed Explanation of Device Making," within fifty paces, even a powerful sixth-rank martial master would find it hard to escape death.

At this time, Charles's injuries had almost healed, and he no longer needed to stay in bed. After assembling these two devices, he couldn't wait to set up dozens of human-shaped targets outside Cuiyi Garden and began testing them.

First was the "Linked Blade Box." As Charles pressed the mechanism, seven refined flying knives shot out one after another, thudding into the targets. Each knife was as fast as a flash of light; Charles could not even distinguish them, only feeling a tremendous recoil in his arm, and then the seven flying knives were already embedded in the human-shaped targets opposite. Nearly half a foot of solid steel was actually pierced through by these seven knives, and the placement was extremely precise.

Charles could not practice martial arts, but his eyesight was extraordinary. At a glance, he could tell that with these seven knives, no matter how fast a martial master of that level tried to dodge, death would be inevitable!

For a moment, he was beaming with joy, unable to contain his delight. He was also secretly amazed—this "Detailed Explanation of Device Making" was truly remarkable. With the "Linked Blade Box" in hand, those sixth-rank martial masters before him were simply lambs to be slaughtered.

And although such deadly weapons were not made entirely by his own hand, they were completed by his own efforts and could be used independently, which made Charles all the more satisfied.

Good things should be shared with others, but at this moment, his usual gang of friends was not around; only Matthew Bolton was watching from the side. Charles turned his head and asked with a smile, "Second Brother, what do you think of this device?"

Matthew Bolton was the second son in his family, and Charles did not treat him as a subordinate, usually calling him Second Brother.