Chapter 121 (1/2)

Strictly speaking, glass does not melt. This strange substance can only be softened at high temperature to form a special state between liquid and solid, which is called glassy state.

It takes a certain temperature for the glass to reach the glassy state. However, the temperature is not fixed. It depends on the minerals in the glass.

Just like the lead glass of later generations, it only needs 500 degrees to begin to soften, while the softening temperature of pure quartz glass is as high as 1600 degrees.

However, most of the glass made by Europeans in this era is ordinary glass, so the stone bear estimates that it can be softened at about six or seven hundred degrees. After all, the temperature of the alcohol lamp used in future laboratories is only about 1000 degrees, but most of the glass can be softened with alcohol lamp.

Stone bear has no alcohol lamp, and no gas burner with higher temperature. He can only soften all the broken glass with the help of a crucible, and then use an iron tube to dip in the liquid glass to blow what he needs.

”The glass will soften later, and then I will blow some glassware I need with this iron pipe. Kuaima, I need you to give me a hand. ” Taking advantage of the heating gap, the stone bear began to roll.

Kuaima nodded for sure.

”Later, when I start blowing glassware, you need to hold the bottom of the glassware with a heated tongs. At that time, the glass will have a certain adhesion with the tongs. At this time, you need to hold the bottom of the glassware slowly and evenly and pull it down. The speed should not be too fast, but it should not be too slow. It's about this speed.” Stone bear said while holding the tongs in his hand, he made a downward movement.

”Do you understand?”

The horse nodded again. He took the tongs and made a gesture of lifting. Then he pulled down slowly and evenly as if holding something.

Although it's the first time to do this kind of action, but Kuaima does it very well. There's almost nothing to be picky about. Shi Xiong is very satisfied.

”You should practice this action more now. Don't get out of the glass after a while. You're flustered again.” Stone bear light command way, the horse did not hesitate to carry out this order, with a tongs began to practice.

Stone bear took up a pair of tongs and a pair of iron scissors and handed them to hard bone, ”after a while, you take this scissors to prepare. When I say to cut, you have to cut the glass I pulled out without stopping. You just need to cut the top of the bottle I blow out, but you need to hold the glass tube with a pair of tongs and then cut it, otherwise the glass tube will break when it falls to the ground. ”

Seeing that hard bone didn't understand, stone bear explained it to him again as he drew. Until hard bone completely understood what he needed to do, stone bear sent him to practice like a fast horse.

”Finally, you must remember that the temperature of the softened glass is very high. You must not use any part of your body to directly touch the glass, otherwise you will burn some part of your body, or you will die!”

Shi Xiong's words are not alarmist. Once the glass begins to soften, it means that the temperature at this time is at least more than 600. This kind of temperature can't be carried by human body.

Because it is separated by a layer of crucible, the heating speed of glass is much slower than that of alcohol lamp.