Deposed? I couldn't be happier! I wouldn't even be a dog to the crown prince.

"To fly?"

Li Ke scratched the back of his head, which was covered in sweat and grime, looking completely bewildered.

He looked at the dark, pungent-smelling sap he had brought back and couldn't understand what this stuff had to do with "flying." Back in America, he had only seen local tribesmen use it as shoes or to play with it by kicking it around. Aside from being waterproof and elastic, it didn't seem to have much use.

But Li Chengqian didn't have time to explain to him.

For the past six months, His Highness the Crown Prince, who had been lounging around in Chang'an like a salted fish, has unexpectedly displayed the aura of a workaholic.

"Old Xu, convey my order."

Li Chengqian threw a piece of raw rubber back into the bucket, his eyes burning with fervor as if he had seen a priceless treasure.

"Immediately seal off the third workshop of the Eastern Palace Arsenal. No one is allowed to approach it except for Mo Ju and a few core craftsmen designated by me!"

"Transport all the 'rubber' that the third brother brought back over there. Not a single scrap is allowed to be lost!"

He turned to look at Li Ke, patted his younger brother who was as dark as charcoal, and spoke in an unusually gentle tone.

"Third brother, you have truly rendered an unparalleled service to the Tang Dynasty this time."

"Go take a bath and change your clothes. I'm giving you half a month's leave. Go to the 'Garden of Beauties' in the city and have some fun. All expenses will be charged to the Eastern Palace Merchant Guild's account!"

Upon hearing this, Li Ke was so happy that snot bubbles almost popped out of his nose.

"Thank you, brother! I'll go right away!"

Watching Li Ke rush out of the study like a black whirlwind, Li Chengqian shook his head. He didn't even have time to change his outer clothes, slipping on his soft shoes, and went straight into the top-secret workshop under the East Palace.

Over the next ten days or so.

The air above the third workshop of the East Palace is filled with a pungent smell of sulfur day and night.

Mo Ju, along with several craftsmen, coughed repeatedly and had tears streaming down their faces from the fumes.

"Your Highness, although this rubber is elastic, it becomes soft and sticky when heated, and hard as stone when cooled."

Mo Ju wore a thick cotton mask and held a piece of raw rubber that had just been fished out of the pot, his face full of helplessness.

"This stuff is so rough it's uncomfortable to even use as shoe soles, how can you expect it to fit wheel rims? It'll be unusable on the road!"

"Raw rubber is definitely not an option."

Li Chengqian was wearing coarse work clothes and holding a glass measuring cup filled with yellow powder. He was carefully adding the powder little by little to the boiling rubber pot according to the ratio provided by the system.

"This is called sulfidation."

Li Chengqian explained without looking up.

"As long as sulfur is added and the temperature and time are controlled, this soft, mushy waste rubber will undergo a transformative chemical reaction."

"By then, it will be neither afraid of heat nor cold, and its elasticity and wear resistance will increase many times over."

Mo Ju was completely bewildered. What was "sulfidation" and what was "chemical reaction"? This was completely beyond his understanding as a traditional blacksmith.

But he had a blind trust in His Highness the Crown Prince. Since His Highness said it was okay, he would dare to drink it even if the pot turned into poison.

"Increase the pressure! Increase the temperature!"

Li Chengqian shouted loudly.

The craftsman next to him immediately pulled the valve of the steam engine, and scalding steam flowed into the sealed vulcanizing furnace through the pipe.

Three hours later.

When the furnace door of the vulcanizing furnace was opened heavily.

A strong, pungent odor mixed with white water vapor billowed out.

Wearing asbestos gloves, Li Chengqian pulled a dark, circular rubber ring out of the furnace.

He casually tossed the rubber ring on the ground.

"Bang!"

The rubber ring did not make a dull, hard impact sound like cast iron when it touched the ground, nor did it crack like wood.

Instead, it made a muffled thud and bounced half a foot high off the ground!

"It's done!"

Li Chengqian excitedly clenched his fist.

He picked up the black rubber ring and pulled hard. The raw rubber, which would normally crumble at the slightest touch, now displayed astonishing resilience; no matter how hard he tried, he couldn't break it.

"Old Mexican! Did you see that?"

Li Chengqian handed the rubber ring to Mo Ju, his eyes gleaming with a fervent light that seemed poised to change the times.

"This is the true lifeblood of industry!"

"Go! Produce at full capacity according to this formula!"

"Make hollow tubes out of this rubber and fill them with air. Replace all those rickety wooden and iron wheels in Chang'an!"

half a month later.

On Zhuque Avenue, the main thoroughfare of Chang'an City.

Emperor Li Shimin of the Tang Dynasty, who had just returned from an "inspection" in Luoyang, was sitting in his large royal carriage drawn by sixteen pure white horses.

In the past, even though horse-drawn carriages were covered with thick Persian carpets, the violent jolting caused by the wooden wheels hitting the ground when traveling on hard cement roads could still shake a person's bones apart.

They didn't even dare to pick up a cup of tea, for fear that a small hole would spill it all over them.

But today.

Li Shimin held a cup of freshly brewed West Lake Longjing tea, closed his eyes, and leaned comfortably against the soft couch.

"How come this road is so smooth today?"

Li Shimin opened his eyes with some confusion.

He glanced down at the full cup of tea in his hand. Even with the carriage traveling at high speed, the tea only rippled slightly; not a single drop spilled!

"parking!"

Li Shimin suddenly pushed open the carriage door and nimbly jumped down.

He circled his royal carriage, his gaze fixed in astonishment on the wheels encased in a black material.

"What is this? It has such miraculous effects!"

Li Shimin reached out and squeezed the black tire, feeling its incredible elasticity and support.

Li Chengqian, who had been accompanying the emperor, was now strutting over on a two-wheeled "bicycle" (an early prototype of the Mohist school) with rubber tires.

"Father, this is called an inflatable rubber tire."

Li Chengqian supported himself on one leg, smiling as he watched his father's naive and unworldly appearance.

"It's a specialty that the third brother brought back from Dongsheng Prefecture."

"With this thing covering the wheel, it can perfectly absorb all the vibrations transmitted from the ground."

"Not only will the carriage be comfortable, but our Tang Dynasty's cannon tractors and steam-powered cars will at least double in speed after being equipped with it, and we'll no longer have to worry about the chassis being shaken apart!"

Li Shimin gasped upon hearing this.

Double the speed?!

This means that the Tang Dynasty's military deployment capabilities and logistical support efficiency will once again experience a qualitative leap. If trains are the undisputed masters of railways, then with these rubber tires, the Tang Dynasty's war chariots can speed and charge forward on any flat terrain!

"What a treasure! This is truly a divine gift!"

Li Shimin excitedly patted the black tire, and for a moment he was quite fond of it.

He turned his head and looked at his son, who was riding smugly on the strange two-wheeler, a complex emotion flashing in his eyes.

The landscape of the Tang Dynasty truly changed every single day.

If I, the emperor, don't find something to do, I'm afraid I'll really be completely abandoned by this rapidly advancing era.

"The third brother went to America and actually accomplished such an extraordinary feat."

Li Shimin stroked the stubble on his chin, his gaze suddenly becoming profound.

He turned around and stared intently at Li Chengqian.

"Chengqian, since the third brother is doing so well outside..."

"When are Lao Jiu (Li Zhi) and Qingque (Li Tai) going to their fiefdoms?"

"I've been thoroughly fed up with watching them engage in cockfighting and dog racing every day in Chang'an for the past few years!"

Li Shimin's tone conveyed a strong sense of urgency, as if he couldn't wait to pack up all his sons and throw them into the sea.

"There are still so many places on this earth where the Tang Dynasty's dragon flag hasn't been flown. My sons can't all be cooped up in Chang'an, living like useless bums!"