?Zhang Yiman and Hu Sanzi carefully opened a small wooden box, took out a wooden box from it and placed it on the table in front of Yuwen Wen. After the wooden box was opened, a glass rod lay in the brocade cloth inside.

The glass rod is about one and a half feet long as a chopstick. Its two ends are closed and an iron hanging ring is tied with a thin rope on it. The other end is a glass ball with a pool of silver liquid. The silver liquid extends about a quarter of the length of the glass rod along the thin pipes in the glass rod.

The thermometer, a thermometer that looks so ordinary in the eyes of later generations, Yuwen Wen finally made it for half a year in the era of thousands of years ago. He glanced at the treasure that cost thousands of yuan and said, "Start, tell me how you made this thermometer."

Zhang Yiman and Hu Sanzi looked at each other and spoke to introduce the complete production process:

When Langzhu first proposed the word thermometer, he had no idea what it meant, temperature, degrees Celsius, freezing point, and boiling point. The four words "Handzhu" were explained for a long time before he could roughly "understand".

The production of the thermometer is "very simple": first make a glass tube, and there should be a hollow glass ball with thin walls at one end of the glass tube. Secondly, pour mercury into the tube and seal it. Third, calibrate the freezing point and boiling point and divide it into one hundred equal-scores between the two points.

Then it took them half a year to make a physical thing for this "very simple" thing. The most troublesome thing is to make glass tubes. According to the owner's requirements, the smaller the "inner diameter" of the glass tube, the better, and must be straight and consistent in thickness from beginning to end.

Zhang Yiman and Hu Sanzi thought of countless ways and didn't know how much hair they had scratched. Finally, they made it: use the iron pipe provided by Lin Youdi to connect it to the funnel to make an "iron fan" for making glass rods. Pull a tight copper wire at the center of the iron pipe, pour the molten glass frit into the funnel. While forming the glass rod, the copper wire also wraps it in it.

When the glass cools down and is about to solidify, pull out the copper wire and leave the thin pipe in the middle. However, there are some questions about when to extract it. If it is too fast, it will not work. Otherwise, the glass that has not solidified will flow and block the pipeline. If it is too slow, it will not work. The thin copper wire will be wrapped too tightly. When it is pulled out, the pipeline will be twisted or even the front and back sizes will vary, which does not meet the requirements.

With the glass tube, heat one end and blow it into a spherical or cylindrical cavitation with thin walls. After it is done, the appropriate amount of mercury is poured into the glass tube. As for how to achieve "vacuum" encapsulation, Zhang Yiman and Hu Sanzi really can't think of a solution or Yuwen Wen gave a suggestion:

The section of the glass tube filled with mercury was inserted vertically into the boiling rapeseed oil. After the mercury in the tube rose until it stabilized, the glass tube at the mercury liquid level was burned and sealed with fire. Take out the glass tube from the rapeseed oil and cool it down and the mercury in the tube retracted, and a large part of the upper section of the tube was empty, which was a "vacuum".

"The nearly boiling rapeseed oil temperature is more than 300 degrees, so when the mercury in the glass tube reaches this height, it can ensure a range of 300 degrees, and it can also be simply created in it."

This is the original words of the Langzhu Yuwen Wen. They couldn't understand what the meaning of more than 300 degrees and didn't know what the range was. The mysterious "vacuum" still half-understands, but it did not prevent them from making this thermometer according to the Langzhu's ideas.

This step is basically close to completion, and finally the "dividing" of the thermometer, first of all, the calibration of the "zero degree": insert the ball end of the thermometer into the dissolved ice cube, and when the mercury column drops to a certain stable moment, a mark is used as the lower fixed point, which is "zero degree".

It snows in Anlu in winter, and many wealthy families collected ice cubes and put them in the ice cellar at that time and took them out to cool down in summer. Xiyang County Gongfu was no exception, so the work of determining zero degrees was quickly completed. Next is the calibration of "one hundred degrees":

After boiling a pot of water for a period of time, insert the thermometer under the liquid surface. When the mercury column rises and stops at a certain position, it is marked as the upper fixed point, which is the 'one hundred degrees', which is the boiling point.

The distance between the upper and lower two fixed points is the so-called zero to one hundred degrees of gauge distance. This gauge distance is divided into one hundred equal parts, each equally divided into one degree Celsius, marking the 0℃ mark at the lower fixed point, marking the 100℃ mark at the upper fixed point, and marking the same spacing can also be engraved below the zero point and above the boiling point.

"Master Lang, this thermometer is smaller and has measured the temperature under the armpit, and the reading is between 36 and a half degrees and 37 degrees."

The body temperature of a person's armpit is around 36 degrees to 37 degrees. Yuwen Wen asked the two to measure their armpit temperature as a method to test the accuracy of the thermometer. To be honest, it was a bit rough, but it was considered to be cross-age during the Southern and Northern Dynasties more than a thousand years ago.

He carefully picked up the thermometer that had condensed his men's efforts for several months and looked carefully. Thanks to his previous skills in making "glass jewelry" and "glass mirror", the thermometer has a "right look" and is well-crafted. The scale on it is engraved according to the previous method, with a range of -10℃ to 300℃.

‘You can tell the cold and warmth.’ Yuwen Wen said in his heart, ‘I have also spent a lot of effort on my part for you…’

Thermometers, chemical experiments, as well as things that industry, agriculture, planting, and breeding are needed. In addition to "investment", Yuwen Wen also works part-time in science: He gave Zhang Yiman, Hu Sanzi and Lin Youdi what is temperature, degrees Celsius, freezing point, boiling point, inner diameter, vacuum and other "scientific terms".

Then he finally knew what it was to play the piano for a cow: these three didn't understand at all. The freezing point is the temperature when water freezes, and the boiling point is the temperature when water boils easily. Arabic numerals have been taught a long time ago and can still be accepted, but then I don't understand any vacuum at all. After talking for a long time, he could only give up and let the other party fumble and do it first.

The thermometer is of no use for conquering cities and land, but it is of great use for people's livelihood, so Yuwen Wen still took out any money. The other thing Hu Sanzi took out was also a matching thing for use with the thermometer.

"Please look, Lord Lang." Hu Sanzi opened a wooden box and took out a wooden disc. There was a pointer on the disc. The tip of the needle was engraved with an arc that was the same as the circumference of the pointer, and the arc was engraved with a scale.

The hygrometer, to be precise, is a hair hygrometer. The hygrometer made by Hu Sanzi based on his memory when he was in elementary school when he was working as a "scientific expert". The principle is very simple:

Human hair has a characteristic: the amount of water vapor it absorbs in the air increases with the increase of relative humidity, and the length of hair is related to the amount of moisture it contains. This change can be used to make a hair hygrometer.

Anyone has long enough hair. In order to ensure the sensitivity of hair to humidity sensing, alkaline water (lime water) can be degreased. Several hairs are tightened in a bunch, one end of the container and the other end is fixed at the end of the pointer. When the hair expands or contracts due to humidity changes, the pointer will be pulled and rotated directly on the scale plate.

When the air is completely dry, the position pointed to by the pointer is 0. When the water vapor in the air reaches saturation state, the position pointed to by the pointer is counted as 100. The principle and structure are very simple, so Hu Sanzi quickly made a hair hygrometer.

The most important thing after having a hygrometer is to calibrate the scale. Yuwen Wen has no accurate method to do this problem, but to let Hu Sanzi use the method: cover a wooden box with lime, then put the hygrometer inside and cover the lid, and open the reading after a while. At this time, the position of the pointer is 0% rh.

As for the determination of humidity of 100% rh, it is to make a wooden box with open covers on the side, and put a pot of water that has boiled and steamed. Put the hygrometer in it and close the box for a while and open the reading. At this time, the position of the pointer is 100% rh.

After determining the two endpoints of the arc on the dial, divide them into 100 scales, so that a "short-made" hair humidity meter is completed. Now, there are two rough environmental elements such as useful thermometers and hygrometers: temperature and humidity can be measured, which is very useful for some work.

For example, when brewing wine, steaming, cooling, and fermenting wine, it is much more intuitive. Without a thermometer, the specific temperature can only be felt by experience, and experience can only be taught by the master. Without direct physical and chemical parameters, it can only be passed on from generation to generation. Once the natural disaster is in the middle, it will be interrupted.

Another example is silkworm raising. If you want to have high yield and high quality cocoons, you can master and adjust the appropriate temperature and humidity of silkworms of all ages during the silkworm raising process. Yuwen Wen knows nothing about this, but after the temperature and humidity meter is promoted and opened, at least farmers can summarize the experience and lessons learned to control the temperature and humidity at the appropriate stage.

"I did a good job and I will go to the account office to receive the reward tomorrow." Yuwen Wen said with satisfaction. Although the two boys in front of him were their servants, he was still willing to reward the 'technicians'.

"Thank you, Lord."

"The production of thermometers needs to be improved. The smoother the inner wall of the glass tube, the better. The straighter the better, the simpler the production, the better, and the lower the cost, the better!"

The biggest key to a technology moving from a laboratory to practical use is cost. Yuwen Wen’s glass workshop is now really a ‘copy workshop’. It is basically made by hand. Because the shortage of people also restricts the output, he decided to appropriately increase reliable personnel to Zhang Yiman and Hu Sanzi.

The last person to come in to report was Lin Youdi. The "pneumatic cavalry gun" produced by his small workshop for several months was busy with the mass production of twenty shots per shot worth 200 s. As a result, the failure rate was extremely high. This thing has been sentenced to death by reality.

"If you have a land, the other guns except the kind of hand gun used in this public are suspended." Yu Wen Wen was a little unwilling to give up but was helpless. Before the air tightness was solved, the failure rate of the air gun was too high and could only be used as a self-defense hidden weapon. "There are also heavy rain pear blossom needles, and the cloud-piercing arrows are suspended. The shocking cicadas are going to continue."

Seeing Lin Youdi a little nervous, he smiled and said, "Don't think so much. This hydraulic drilling machine is not wasted, right? Zhang Yiman and Hu Sanzi used iron pipes to blow glass, and what you made came in handy."

"Don't be sad, I will ask the glass workshop to make something in a few days and need your help."

"Master Lang. I still can't think of how to do that pressure gauge." Lin Youdi still stammered and told him about the problem he had been struggling with for a long time.Master Lang asked him to find a way to make something to measure the approximate pressure in the air tank. He and his men and several of them could not think of it for several months.

"It's okay, don't be in a hurry." Yu Wenwen didn't care about it. The pressure gauge is another bottleneck restricting the development of air guns. The reason is very simple: the power of air guns comes from high-pressure air tanks. If the air pressure is low, the power is not enough. The air pressure is high. There is a risk of explosion of the tank and poor sealing is more likely to leak air.

Pressure gauge was very ordinary in later generations, but even he didn't understand the principles. Moreover, people in this era could not quantify the inflation of the gas tank without a pressure gauge. From a wider range of uses, pressure vessels and pipelines must have pressure gauges to ensure safe production.

Now they rely on stupid methods to solve the pressure problem: it depends on the number of times of pumping, but the number of times of pumping hundreds of times often forgets how many times they hit, so before this problem is solved, the air gun can only be used as a hidden weapon.

"I'll talk about this later. I have something new for you to do."

"What do Lang mainly do?"
Chapter completed!