As Xiaoyao Tower’s fame rose by the day, honeycomb briquettes warmed 10,000 households, floral perfume water scented the whole city, the Zhenguan plow turned fertile soil, and the membership system won people’s hearts, 16-year-old Du Heng clearly understood one thing: in Chang’an, without the protection of nobles and grandees, you could not take a single step.
Although Drunken Immortal Pavilion was defeated, its backer, Zhangsun Wuji, never made a move.
Du Heng understood that this was not backing down, but lying low.
The real storm had not arrived yet.
“You must befriend the sons of meritorious officials, stand outside the court, and be protected within the streets and marketplaces.”
Du Heng said this to Princess Changle, with a voice as calm as a deep pool, “Without support from the military and the meritorious nobility, Gezhi Institute is a tree with no roots.”
Changle nodded, her gaze far-reaching, and said, “Cheng Chumo and Qin Huaiyu both value righteousness over profit, and they are straightforward and loyal, so they can be friends.
“Cheng Yaojin looks crude but is actually shrewd, and Qin Qiong comes from a family famed for loyal valor, so these 2 houses are Your Majesty’s trusted confidants.”
3 days later, Cheng Yaojin indeed came with his son to visit.
Old Cheng wore a coarse cloth robe, yet a horizontal saber still hung at his waist, and he strode into Xiaoyao Tower with a booming voice: “Little Du! I’ve eaten Xiaoyao Pork for 7 straight days, and today I’m sending my worthless son to learn your craft… if he can’t learn it, I’ll break his legs!”
Cheng Chumo was 19, broad-backed and thick-waisted, with heavy brows and big eyes, and a temper like raging fire.
Qin Huaiyu was 18, a bit more quiet and refined, yet with eyes like blazing torches and steady, grounded steps.
Both wore everyday clothes and brought no attendants, clearly showing sincere intent to befriend Du Heng.
16-year-old Du Heng welcomed them into the “gong”-shaped private rooms, where there was no wine and no entertainment, only a stove, a table, and a glass cup.
Du Heng’s build was not fully grown, yet Du Heng already stood as straight as a pine, and Du Heng’s steady gaze far surpassed Du Heng’s peers.
Du Heng personally stir-fried the dishes, with movements crisp and flowing like drifting clouds and running water.
Cheng Chumo fumbled clumsily, oil splattering all over, and the wok almost flipped over, yet Cheng Chumo enjoyed it immensely and laughed loudly, “This is harder than practicing with a spear!”
Qin Huaiyu did not rush to start and only observed the pulleys food-delivery system, the “suggestion book” on the wall, and the “Ingredient Traceability Board” beside every dish.
Qin Huaiyu suddenly asked, “Brother Du, you are young, yet everywhere I look I see the thinking of ‘gewu’… pulleys save effort, traceability prevents counterfeits, and the suggestion book gathers the wisdom of the people. Do you have even greater ambitions?”
Du Heng did not answer, and Du Heng only took a glass cup, poured rose dew, and pushed it before the 2 of them.
The cup body was crystal-clear, bright enough to reflect a face, and under the autumn sun outside the window, it looked as if it held a pool of rosy clouds.
“This cup is 10 times better than those from the Western Regions, and the price is only 100 wen.”
Du Heng said, “If we mass-produce it, commoners will all be able to use it, and Hu merchants will no longer be able to reap obscene profits from glass.”
Cheng Chumo was startled and said, “You made this?”
“Exactly.”
Du Heng nodded and said, “Gezhi Institute is already being prepared, and the first product will be glass, the next will be medicine, and in the end we will forge instruments that benefit the nation… like new plows, new armor, and new devices.”
A sharp light flickered in Qin Huaiyu’s eyes as Qin Huaiyu said in a low voice, “If protection is needed, the young men of the Qin family are willing to give our lives.”
Cheng Chumo slapped the table and sprang up, rattling the bowls and plates, and said, “Old Cheng’s family feels the same! Whoever dares lay a hand on Xiaoyao Tower can first ask the spear in my hands!”
The 3 of them then swore brotherhood in Xiaoyao Tower’s rear garden.
There was no incense and no wine, only 3 cups of rose dew.
Du Heng was 16 and became the younger brother, Cheng Chumo was 19 and became the older brother, and Qin Huaiyu was 18 and took the middle position.
On the day of the oath, Du Heng gifted the 2 of them glass cups, and 4 characters were engraved in shadow script on the cup bottoms: “gewu zhizhi.”
The 2 of them returned the gift with horizontal sabers, and the saber hilts were inlaid with a Xiaoyao Tower wooden plaque engraved with the 2 characters “Protect the Way.”
“From today on, Xiaoyao Tower has Cheng and Qin as protectors!”
Cheng Chumo laughed loudly, and the sound shook the roof tiles.
The circle of meritorious officials’ sons quietly accepted Du Heng.
A few days later, Yuchi Baolin, Fang Yiai, Li Ji’s son Li Bi, and Chai Shao’s nephew Chai Zhewei, among others, gathered at Xiaoyao Tower and booked 3 private rooms: “Rites, Music, and Archery.”
They did not come for the food, but to see the “divine man who can draw a chicken that moves”… because earlier, Du Heng drew the 《gewu fairy tale》 for little Zi’er, and inside it there was a diagram of a mechanical chicken pecking rice that actually moved.
16-year-old Du Heng was neither servile nor overbearing, and Du Heng received them with the great path of gewu:
– Du Heng explained to Yuchi Baolin the principles of levers saving effort, which could help cavalry lift 50 jin of heavy armor with one hand.
– Du Heng analyzed for Fang Yiai the method of crop rotation for enriching fields, and Du Heng improved the Zhenguan plow into the “integrated crop-rotation plow,” which could increase yield per mu by 30%.
– Du Heng even taught Li Ji’s son how to distinguish medicinal herbs and make mint balm to relieve summer heat in the army.
Everyone was full of admiration, and Yuchi Baolin slapped a thigh and said, “Brother Du is young, yet has the bearing of a state-worthy talent! Brother Du is 100 times better than those sour pedants who only know how to chant poetry!”
Fang Yiai added, “My father often says that governing the state lies in the real, not the empty. Only after meeting Brother Du today did I understand what ‘practical learning’ truly is.”
Zhangsun Wuji heard of this, and Zhangsun Wuji’s expression darkened.
In Zhangsun Wuji’s residence, Zhangsun Wuji coldly said to confidants, “This boy is 16, yet he can already use fine food to bind nobles and grandees, use gewu to gather people’s hearts, use glass to control trade routes, and use membership to gather the people’s wealth. If he is not eliminated, he will surely become a great disaster.”
However, Li Shimin personally praised Du Heng as “a true state-worthy talent,” and the Crown Prince Li Chengqian also sent people to secretly buy Xiaoyao Tower Jade Card, so Zhangsun Wuji did not dare move rashly and only ordered close surveillance.
Yet Du Heng rode the momentum and pressed forward.
Du Heng invited Cheng Chumo and Qin Huaiyu to tour Dujiawa manor.
When Cheng Chumo and Qin Huaiyu saw pulleys drawing water to irrigate 1,000 mu of fields, a compost pool fermenting locust manure, and an experimental plot planting ziyunying for nitrogen fixation, Cheng Chumo exclaimed in shock, “If this method is used for military farm garrisons, it can save the labor of 10,000 men! The border army will no longer worry about provisions!”
Qin Huaiyu carefully asked about the glass formula and said, “If you make it into twin-tube lenses, you can observe enemy activity 10 li away… this is a telescope!”
Du Heng smiled and said, “That is exactly my intention. Gezhi Institute has already trial-made an initial sample, but the lens purity is still insufficient.”
The 3 of them planned great undertakings together.
On the way back, Qin Huaiyu murmured, “Brother Du, if you make a glass telescope, I can present it to my father-commander for use at the Shuofang frontier.”
Cheng Chumo said, “My father commands the Left Martial Guard, so if you develop new armor… like honeycomb-structure shock-absorbing armor… or new devices… like a repeating crossbow mechanism… it can be tested in the imperial guards.”
16-year-old Du Heng felt completely settled inside… military support was the foundation for Gezhi Institute’s survival, and recognition from the meritorious nobility was the basis for Xiaoyao Tower’s foothold.
Princess Gaoyang came again and sneered: “You sure know how to pull factions together.”
Du Heng replied, “This is not for forming a clique, but for shared benefit. The art of gewu needs military protection, popular use, and merchant promotion to become a great undertaking. If you only shut the doors and build devices, in the end it is just empty armchair strategy.”
Gaoyang stared at Du Heng for a long time before suddenly saying, “This palace can also help you.”
Gaoyang took out a scroll of frontier terrain maps from Gaoyang’s sleeve and said, “Shuofang has heavy wind and sand, and glass lenses easily get coated with dust. I have already ordered craftsmen to trial-make dust covers… if you make the lenses, I will protect the lenses.”
Du Heng bowed deeply and said, “Thank you, Your Highness.”
Late at night, Du Heng sat alone in the study.
Outside the window, the moon shone over Chang’an.
Under Xiaoyao Tower’s glass lanterns, Cheng Chumo and Qin Huaiyu were tasting the newly made flaxseed drink, laughing and making a din, with horizontal sabers leaning against the wall and glass cups reflecting moonlight in a shining glow.
And 16-year-old Du Heng knew that true allies were not at the drinking table, but on the future battlefield and in the workshop.
Today’s cup of rose dew might tomorrow be exchanged for thousands upon thousands of troops and warhorses, and today’s words “investigate things to extend knowledge” might tomorrow forge the nation’s crucial instruments.
Du Heng raised the brush and recorded the matter:
＞ The meritorious officials’ sons have been secured, and the military channel has just opened.
＞ Glass is the medium, gewu is the bridge, and the 4 dimensions of military, people, merchants, and learning have begun to take shape.
＞ Next step: present glass cups to the palace and seek the building of a royal glass workshop.
Du Heng knew that Zhangsun Wuji’s blade would eventually fall.
But Du Heng already laid out the board… above was a princess’s protection, in the middle was an alliance with the meritorious nobility, below was the people’s support, and outside were the Hu merchants’ trade routes.
This step was taken steadily, and it was taken far.
A youth’s ambition lies not in age, but in investigate things to extend knowledge, and in benefiting the world.
Deep in the lamplight, Great Tang’s future was quietly being reshaped by a pair of 16-year-old hands.