Engaged in business or handicraft production as "house slaves", or engaged in commodity business. This is not only the case with vassal kings and nobles, but also with the gentry and wealthy households, after all, the power of an individual is limited.

And for Shi Yiwen, who has been in Wanli for more than a year, Jiang Fangzhong's dedication is his first real "house slave", after all, before this, whether it is Xiao Lian, Kou Yun and others, or even Chen Huan bought in Songjiang, they are all passively accepted, only Jiang Fangzhong is actively accepted by him.

Perhaps, this is also a manifestation of some kind of adaptation to the times.

Of course, this adaptation is also due to the need for this.

According to the rules of the donation, the workshop was "rewarded" to it again, just like the donated land, the land is only nominally returned to the owner, and the sacrifice must be returned at the same time, and the donor only handed over the taxes and taxes that should be handed over to the government to the owner, and the homestead still has to be returned to him.

Otherwise, no one is crazy enough to give all the mansion to others, and he will be a slave to his master with a shy face. That's not a contribution, that's brain-dead.

Compared with the Jiang family's worthless family property, Shi Yiwen values people, with people and craftsmen, this glass factory is naturally set up in Lugou.

The construction of the glass factory was also fast, because I just wanted to practice the craft, so I just built a reverberatory furnace to melt glass in the iron factory, and then began to make glass. The raw materials for the production of glass are very simple - quartz sand, limestone, feldspar and soda ash are all ready-made materials, and natural soda ash is mainly produced in salt lakes and has always been an important commodity for export production.

According to the glass recipe found in the library, the prepared raw materials are heated at high temperatures in a reverberatory oven to form a uniform bubble-free glass melt, and this melting process takes about eight hours.

"Young master, this stove of our house is really unusual, it has only turned into water in four hours, if it is rested on the old stove, it will take at least a day and a night."

Seeing the raw materials in the furnace melting to form a glass liquid, Jiang Fangzhong no longer had the slightest doubt in his heart, not to mention anything else, just for this furnace, it was worth it to dedicate it to the Shi family. He was even thinking in his heart that he would replace the stove in the workshop with such a stove in the future.

Looking at the change in Jiang Fangzhong's eyes when he stared at the stove, Shi Yiwen, who knew what he was thinking, also poked it out, but asked.

"Can you blow now?"

"It's definitely okay, it's all turned into water."

As he spoke, Jiang Fangzhong's heart jumped to his throat, and now, now the young master is going to pass on his method of making flat glass?

"In this case, you first poke an iron blowpipe into the furnace and dip it in some liquid glass......"

Standing in front of the fiery hearth, Shi Yiwen gave instructions, and Jiang Fangzhong followed.

"After taking it out, I swirl it and blow through the blow pipe...... Yes, that's it...... You also watch, to slowly expand the molten glass into a spherical shape, and then put it in this hemispherical iron groove and continue to rotate, yes, to make the spherical shape ......."

While instructing Jiang Fangzhou, Shi Yiwen also paid attention to the craftsmen around him, after all, the production of glass in the future is not a one-man business.

"There's a little cold water in this trough that cools down. At the same time, cool the other end of the blowpipe with water for easier handling. You see, now that the glass has cooled down a little, at this time, the blow pipe is put into the furnace, dipped it twice, and repeated many times until the molten glass becomes a ball with a diameter of about 20 centimeters, and then it is placed in a scoop-shaped iron trough, and while continuing to cool the lower end of the blow dryer with water, blow air from the upper end to make the spherical shape gradually expand and become a cavitation ......"

Seeing that under Jiang Fangzhong's blowing, the red glass ball turned into a cavitary glass ball, Shi Yiwen continued.

"You should pay attention to the fact that during the blowing process, you should always turn the blowpipe to make the spherical cavitation thickness uniform, which is very important. If the temperature of the glass is lowered, the blow pipe is heated deep into the oven to soften the glass bubbles. At this time, the blow pipe is suspended in the air and hung in the deep trough, and the glass bubble will slowly fall into the trough to form a cylindrical ......"

Under the guidance of Shi Yiwen, Jiang Fangzhong followed his guidance step by step, but he had a lot of doubts in his heart, didn't he want to make flat glass? What is this for?

“…… At this time, the thickness of the glass cylinder is uneven, generally thicker at the bottom and thinner at the top. However, the glass cylinder has been cooled and solidified and can no longer be blown, so it must be reheated in the oven, taken out after melting and softening, swinging and rotating in the deep groove, and blowing at the same time, the purpose is to make the thickness of the cylinder wall uniform. If it cools down again, it is re-entered into the oven and so on, until it is blown into a glass cylinder of uniform thickness, which can reach up to two meters ......"

Of course, due to lack of skill, Jiang Fangzhou only blew out a glass cylinder about one meter long, but even so, it was beyond Shi Yiwen's expectations.

Then, the rest is simple: after the glass tube is blown into it, the dark lines on the glass cylinder are produced through the principle of hot and cold phase excitation, and then the side is lightly rotated to remove its bottom, removed from the blow tube, and then cut into several sections in the same way, each section is longitudinally dissected, and finally the cylinder is spread into a flat sheet into a flat sheet into a spreading furnace.

In this way, when it comes out of the oven, a few pieces of bright and crystalline flat glass will be formed, although because of the process, there will inevitably be dark lines and spots on the glass, but after the annealing of those pieces of flat glass, Jiang Fangzhong and the craftsmen around him are all dumbfounded.

"This, this glass is really blown out?"

Even though it was a glass made by himself, Jiang Fangzhong still looked very surprised.

"Yes, this method is called the blowpipe spreading method."

Until the mid-to-early 20th century, this method of manual blowing tube spreading was the most important method for the production of flat glass, and even until the late 20th century in many countries, it was this seemingly backward method that made cheap glass windows into thousands of households.

"Less, young master, this, this method is indeed not difficult, it is not difficult......"

In addition to being surprised, looking at the few pieces of shiny glass, especially when they were carried down, looking at the almost transparent glass, Jiang Fangzhong's eyes showed a somewhat complicated look, his breathing even became a little rapid, those eyes stared at the glass, moving with its movement. So much so that he himself did not notice the change in his demeanor, and at this moment, he heard someone in his ear say.

"How's it going, what are you thinking? Do you want to start your own factory? ”