The Blast Furnace Goes Into Operation: Li Zhi’s New Innovation

The abacus was something so simple to make that the craftsmen at the Imperial Workshop hardly gave it a second thought. Thus, the next day, Pei Feishu personally handed an abacus to Li Zhi.

The moment Li Zhi received the abacus, a familiar sensation welled up within him. He had always been interested in mathematics since childhood, and such a tool was hardly foreign to him. Supporting the abacus with his left hand, he deftly manipulated the beads with his right, quickly sliding them from one end to the other. When he finished, he smiled at Pei Feishu and said, "With this, bookkeeping this year should be much faster."

When Li Zhi presented the exquisitely crafted abacus to Li Shimin, the emperor did not immediately grasp its purpose. Only after Li Zhi explained its function did Li Shimin, somewhat amazed, ask, "Just yesterday I spoke to you about bookkeeping, and today you have made this?"

Li Zhi replied, "I merely proposed the idea; the craftsmen of the Imperial Workshop made it."

Li Shimin studied the abacus for a long while, unable to relate the object in his hands to the calculation boards he had known. With a puzzled expression, he asked Li Zhi, "Tell your father, how did you come up with such an improvement?"

Li Zhi answered, "I am studying mathematics, and I've long found the calculation board inconvenient, so I've always wanted to improve it." He paused, then continued, "Yesterday I heard that Father was troubled by bookkeeping, and in my urgency, this idea came to me."

Li Shimin, upon hearing this, fondly patted his son's head. He said, "You thought of this just to help your father solve his worries?"

Li Zhi explained, "I had been thinking about it before, but yesterday, being suddenly anxious, the idea came to fruition."

Li Shimin was so delighted that he lifted Li Zhi in his arms. Smiling at Zhang Anan, who stood nearby, he said, "Anan, look how clever Zhinu is—yet at this moment, he doesn't even know to tell a little lie to please me."

Zhang Anan responded with a smile, "Your Majesty, you may not know, but His Highness the Prince of Jin has never spoken a false word."

Li Zhi, surprised by Zhang Anan's words, looked at him in wonder, thinking: Who would have thought that this eunuch knows me so well?

Li Shimin, intrigued, asked, "Don’t deceive me—what child never lies?"

Zhang Anan glanced at Li Zhi with a gentle smile and said, "Your Majesty, I oversee so many palace maids and eunuchs, and none have ever reported that the Prince of Jin has lied."

Li Shimin turned to Li Zhi and asked, "Zhinu, is what Anan says true?"

Li Zhi replied, "Father, I truly dislike lying."

Li Shimin laughed, "What a fine son I have. Your father likes honest children best."

Seeing his father's happiness, Li Zhi smiled as well. He refrained from lying about other matters because everything he did now carried a measure of deception. He feared that, if he lied too often, he might one day be unable to believe in his own reality.

With Li Zhi’s improved abacus, bookkeeping was indeed much faster that year. Tasks that had previously taken until the end of August were completed by early August. The officials responsible for tallying silently thanked Li Zhi in their hearts.

Almost at the same time, the first blast furnace at the ironworks was completed. Li Shimin decided to personally lead the officials of all departments to observe the furnace’s operations.

The new workshop was thirty meters tall; aside from the surrounding walls, which were made of blue bricks and cement, nearly all other structures were built with steel. With the current technology, such a project was already a marvel. Yet even more astonishing was the blast furnace, which towered twenty meters above the ground. Its massive body resembled a work of art, adorned with several mysterious pipes. The top of the furnace was open, and workers were busy adding materials. After a period of frantic activity, the furnace top was slowly closed.

After reporting to Li Shimin, Baken loudly announced, "Ignite!"

At his command, a pipe at the base of the furnace suddenly spouted flames, swiftly igniting the charcoal inside. This ignition device was designed by Li Zhi, with tung oil as the fuel.

As the furnace was kindled, two enormous bellows powered by water wheels began blowing air into the furnace from both ends.

Li Zhi said to Li Shimin, "Father, the refining process will take less than three hours; you may return to the palace and rest."

Li Shimin shook his head without hesitation, "I came today to see the ironmaking; resting here will suffice."

Li Zhi nodded and quickly led everyone out of the increasingly hot workshop, arranging for tables and tea beneath the shade of trees—now the hottest time of the year. Even so, everyone soon found themselves drenched in sweat.

At this moment, Baken produced several palm-leaf fans and distributed them. Li Shimin and the others took the fans without fuss and began fanning themselves vigorously. Li Zhi himself could barely stand the heat, fanning himself continuously and thinking how wonderful it would be to have an air-conditioned room and an ice pop.

As he thought of ice pops, his eyes suddenly lit up. He slapped his thigh and exclaimed, "I've got it!"

His sudden outburst startled everyone.

Li Shimin asked, puzzled, "Zhinu, what are you doing?"

Li Zhi replied joyfully, "Father, I've thought of something wonderful—a perfect remedy for the summer heat."

Li Shimin said, "What have you thought of? Speak quickly, and I will send someone to fetch it at once."

Li Zhi shook his head, "Father, it doesn’t exist yet, but I can make it quickly."

Li Shimin said, "In that case, hurry."

Li Zhi immediately summoned Liu An, whispered instructions in his ear, and soon Liu An rode off toward the palace.

Meanwhile, under the curious gaze of the others, Li Zhi asked Baken to prepare two large jars of water, as well as three clean bronze basins. Next, he instructed Baken to set aside some boiled water to cool. He then had Baken fetch a thick bamboo pole, split its thinnest part into bamboo skewers, and fashioned the remaining bamboo into two molds sized to fit the bronze basins.

Liu An returned swiftly, carrying two cloth bags—one large, one small—and a wine pouch. Li Zhi took the wine pouch, poured its contents of milk into a bronze basin, and handed it to Baken to heat. Then he took some sugar from the smaller bag and divided it between two basins.

After the milk was heated, Li Zhi instructed Liu An to pour it evenly into the two basins containing sugar, then add some of the cooled boiled water...