These smiles come from the heart.

The reason is simple. They not only gained recognition from the emperor but also realized their self-worth.

"The method to solve the problem of adhesion between iron molds and molten iron must be kept secret." Chongzhen instructed.

The strategic significance of the iron-cast cannon is too great!

If before only one thousand cannons could be produced each year, after switching to iron molds, the same craftsmen could produce several times the number of cannons each year.

As quantity increases, costs can decrease.

For the Ming army, artillery is no longer a luxury!

"Your Majesty, don't worry. There are only two people who know this method. One is Jiao Xu, and the other is Fang Yizhi." Fan Jingwen supported Jiao Xu with his left hand and pointed to a middle-aged man behind Chongzhen with his right hand.

The man was wearing a blue official robe, had a thin face and a medium build, and looked handsome and elegant.

"I, Fang Yizhi, the reviewer of the Hanlin Academy, am here to see Your Majesty!" Fang Yizhi bowed to Chongzhen.

Chongzhen was stunned for a moment.

Fang Yizhi was a famous thinker, philosopher and scientist in the late Ming and early Qing dynasties.

The word "physics" comes from his encyclopedic academic work "A Brief Introduction to Physics".

In addition to his contributions to physics, medicine, philosophy and geography, Fang Yizhi also made amazing achievements in astronomy.

Because he made the correct guess at the time that Venus and Mercury orbited the sun.

Chongzhen stared at Fang Yizhi's face and nodded secretly: This scientist from the Ming Dynasty is truly rare!

"Fang Yizhi." Chongzhen called his name calmly.

"I'm here!" Fang Yizhi clasped his fists and bowed again.

"I have a question for you."

"Your Majesty, please enlighten me!"

Chongzhen pointed at the falling snow outside the military tent and asked, "Why do you think it snows from the sky? And why does the snow fall down instead of flying up?"