Looking at Bi Maokang and Song Yingxing's faces, Zhu Youzhen was a little suspicious, isn't this another big piece of complete glass, why are you still unhappy.

Seeing that the Son of Heaven was a little puzzled, Song Yingxing directly ordered someone to take something that weighed about five catties and put it on the glass, and then said.

"Your Majesty, this is an iron block to test the hardness of glass, it weighs five catties, Your Majesty, look at it again."

After watching Song Yingxing's operation, Zhu Youzhen probably knew his intentions, so he stepped forward and looked at the hardness of the glass.

As expected, the piece of glass began to crack on all sides, centered on the iron scale.

"It's too brittle!"

Zhu Youzhen picked up a small piece of broken glass, and then gently broke it with his hand, and with a click, the glass was halved.

In later generations, although Zhu Youzhen was not engaged in the production of glass, he did not touch glass in his daily life, except for some special handicrafts, such brittle glass could not be seen in later generations.

Not to mention that kind of explosion-proof glass, in later generations, even if it is installed on doors and windows or used as mirrors, it will be broken even by hand.

Definitely where there is nothing but the problem.

Zhu Youzhen carefully pondered the production process of Xishan Glass Factory, and suddenly, what Bi Maokang said just now flashed through his mind in an instant.

'Do you think this glass is like forged steel, which needs to be smelted twice or more times to be tough? ’

Zhu Youzhen turned his head and glanced at Bi Maokang, and said loudly.

"Lao Bi, you reminded me well."

Bi Maokang looked at the Son of Heaven for some reason, and then looked at Song Yingxing, but Song Yingxing, like himself, was full of confusion.

Seeing that the Son of Heaven was excited, Bi Maokang and Song Yingxing bowed down and asked with some uncertainty.

"The ministers are stupid, please make it clear to Your Majesty."

"Haha, that's supposed to be the problem."

At this time, another furnace of glass solution came out, and Zhu Youzhen directly led everyone to see the operation of the craftsmen.

As before, the solution is placed on a flat abrasive, and then the air bubbles are expelled and formed repeatedly with an iron roller.

After the fire has cooled a little and the red color has subsided, the craftsman with thick insulating gloves will pick up the glass and quench it.

However, at this time, he was stopped by Zhu Youzhen.

Everyone looked at the Son of Heaven in puzzlement, Zhu Youzhen looked around, and then said slowly.

"Lao Bi and Lao Song, you two will tell me why the blacksmith master put the hot iron into the water to quench it?"

Instead of explaining the doubts positively, Zhu Youzhen asked questions instead.

For the process of ironmaking quenching, Song Yingxing and Bi Maokang naturally knew it.

Ironmaking is not only repeated beating, but also repeated hot and cold quenching can also make ironware tougher.

Song Yingxing stepped forward to explain the principle of iron quenching, and when he said to increase the toughness of iron, he was dumbfounded, and then said.

"Your Majesty is saying that this glass cannot be quenched in water?"

Bi Maokang also pondered at this time, and it seemed that there was a problem with the quenching step.

But what the problem was, the two didn't understand it for a while.

"Iron-based is hard, quenching is more than hard, but glass is brittle, rash quenching is more than brittle, its properties are different, the process should not be the same."

After Zhu Youzhen finished speaking, Bi Maokang and Song Yingxing also understood that the production process of this glass is compared to steel, except that there is no forging, the steps of forming and quenching are the same.

In fact, this does not blame Zhu Youjian, although he knows the production principle of glass, but the production process of glass is not recorded in middle school textbooks, so this set of processes is also explored by Bi Maokang and Song Yingxing.

Because it also requires high-temperature smelting, the subsequent steps are all the same.

In fact, what Zhu Youjian didn't know was that there was an annealing procedure in the glass production process, which was put in a depyretic chamber after the glass was formed.

Like today's Xishan Glass Factory, it is absolutely impossible to quench the glass that is still hot in cold water.

Of course, the kind of advanced operation in the annealing chamber, Zhu Youzhen hadn't remembered it yet, so he could only let the glass cool down naturally.

According to the explanation of the Son of Heaven, the molded glass was not directly quenched in cold water, but slowly cooled in the mold.

About a quarter of an hour later, a craftsman stepped forward and touched it with his hand, and the glass had cooled completely.

The large piece of glass was removed from the mold and placed on the test board, Song Yingxing picked up the five-pound weighing weight from before and gently put it on.

Everyone's eyes were looking at the piece of glass, Zhu Youzhen was also looking forward to it, and Song Yingxing and Bi Maokang seemed to be extremely nervous, even more nervous than Zhu Youzhen.

Compared with the parties, they have to pay more attention to the face of the Son of Heaven, after all, the embarrassing scene after the test failure has to be resolved by the two of them.

The result did not disappoint, only to see that under the five-pound scale, the glass was not damaged at all.

Song Yingxing was not at ease and took a closer look in front of the mountain, and there were indeed no cracks.

The crowd immediately shouted that the Son of Heaven was wise.

But Zhu Youzhen ignored everyone's compliments, reached out and picked up a heavier scale, and then pressed it.

Everyone held their breath and stared, all staring at the increasing scales, until Zhu Youzhen pressed the largest scale, and the glass was still intact.

Everyone shouted again, but only Zhu Youzhen felt that something was wrong.

The weight of these scales adds up to fifty catties, and it is said that the glass cannot withstand such a great pressure.

Looking at this piece of plate glass carefully, Zhu Youzhen suddenly remembered.

Because of the board below, as long as the glass is strong enough, the pressure is not only dispersed, but also estimated to be all conducted to the board, and the strength of the glass cannot be tested.

Of course, because they have not yet popularized some knowledge of pressure and mechanics, Song Yingxing and Bi Maokang do not know the principle of this, plus the previous glass is indeed brittle enough, and no one thought of the fallacy of this test.

After Zhu Youzhen smiled awkwardly, he ordered someone to hang the middle of the glass in the air and put it on the supports on both sides.

Everyone looked at the Son of Heaven inexplicably, not knowing what he was going to do next.

So, in full view of everyone, Zhu Youzhen picked up a one-pound weighing stone and put it down in the suspended position of the glass.

At this time, everyone naturally understood, and the wheezing seemed to stop for a while, and they all looked at the glass nervously.

Because Zhu Youjian had popularized the importance of a uniform scale to Bi Maokang before, and collected a complete set of rulers and instruments from the ship, and even handed over the vernier caliper to Bi Maokang how to use it.

Therefore, the production of Xishan factories is standard, and the thickness of this piece of glass is exactly one centimeter, so after this pound of weighing stone is put up, it is not broken immediately.

Everyone breathed a sigh of relief, but before the breath was finished, they saw that the Son of Heaven took out another five-pound scale.