Trusting the emperor, Yang Biao immediately sent people to find graphite after receiving the secret letter. He then gave the blueprints to his servant, instructing him to find a blacksmith to forge the stone according to the blueprints.

However, after a long time, he still couldn't find any news about graphite, and Yang Biao gradually forgot about it. Now, looking at the graphite in front of him, Yang Biao remembered the coal stove.

If it is truly as the Emperor said, once we have graphite and coal stoves, then not only Liaoxi, but the entire northern region will be free from the torment of severe cold. This will be of unimaginable help for the future northward expansion of the Han Dynasty.

After the servant left, Yang Biao looked at the constable again and asked, "Ask them if they know the exact location of these graphites, and how many of these things they have over there?"

"promise!"

Then the officers began talking to the Wuhuan people again.

A moment later, the constable turned to Yang Biao and said, "Reporting to Prefect Yang, they said that these graphite stones are found in the mountains and forests within Lingyuan County, and there are so many that the locals can use them inexhaustibly!"

"Alright! Alright! Take them downstairs first, give them a good meal, and then settle them in properly!"

"promise!"

The officer accepted the order and then left with several Wuhuan people.

Before long, the servants, along with several other servants, brought over the coal stove and several sections of the chimney.

Yang Biao then had his servant bring the blueprints and directed several servants to assemble the coal stove according to the blueprints.

Before long, a coal stove, almost like those used in modern rural areas, appeared before everyone, with sections of chimneys extending out of the windows.

After glancing at the coal in the bamboo basket, Yang Biao said, "Put these graphite pieces into the furnace and light them!"

"Young master... this..."

Yang Biao's words startled the servant. He had clearly heard what the constable had said: if this thing burned, it could be fatal. He hesitated and stood frozen in place, unable to move.

"What do you mean by 'this' and 'that'? Would His Majesty harm you or me?"

Seeing that the servant did not move, Yang Biao glanced at him with displeasure.

The servant quickly replied, "No...no...."

Yang Biao's eyes widened. "If you don't know how, then hurry up and go!"

"Okay, sure!"

Seemingly sensing that Yang Biao was getting angry, the servant dared not delay any longer and quickly had someone bring some firewood to put into the stove and light it.

When the temperature was about right, the graphite was filled into the furnace one by one.

Before long, the graphite began to burn, and plumes of black smoke were expelled outside through the chimney.

Yang Biao and his companions, who were near the coal stove, did not smell any strange odor; instead, they only felt waves of heat.