Shang Wen was lying on the mat, he really couldn't sleep, no matter how he posed in various positions, he just couldn't sleep.

Not being able to sleep is a very uncomfortable thing. Shang Wen got up and drank his saliva. I want to keep sleeping. But forget it. Cheer up and stay up late. this era. Not even coffee, refreshing things, only tea.

But let's drink water. The tea leaves are somewhat bitter.

Shang Wen sat down and quietly sorted out his thoughts. First of all, it's a place to sit. this era. Everyone was still sitting on a mat, and even chairs and stools had not yet appeared. To sit, in fact, is to kneel. This is a great test of human willpower. Shang Wen struggled to discuss the government every time. Especially when it comes to those huge war plans, Shang Wen always stands up and speaks first, because sitting is kneeling. I can't stand my knees. However, Shangwen believes that such a long-term kneeling. I don't know if there is such a disease as arthritis.

Thinking of this, Shang Wen realized that his previous inventions were too concentrated in heavy industry, or biased towards very technical things, and he had serious neglect of some of the life around him. For example, the surrounding furniture. Shang Wen is not a single invention. If it weren't for Yingyu's accidental proposal today. Shangwen has almost forgotten that life can be better.

Focusing too much on one thing tends to overlook a lot of things.

Come to think of it. Shang Wen's interest came all at once. furniture, sofas, chairs, stools. Modern style coffee table, work desk. It would be nice to be able to add a boss chair. Shang Wen took out a stack of paper and began to sketch the figure. Relatively modern woodworking machines have already appeared. These things are not difficult to process. Couch. There are no sponges yet. It can only be made of old-fashioned spring sofas.

A backrest chair with springs or thick styrofoam, etc., with armrests on both sides. That's a basic overview of the sofa, with which it can be used in other places, not just at home. There are also horse-drawn carriages for going out. It is also possible on the carriage. Thanks to the four-wheeled carriage. The load capacity has not only doubled, but more importantly, it has carried people and goods. have improved a lot. If you add a sofa, it may be more comfortable for the passengers. Plus transparent glass. It's very modern in style.

In addition, there are a lot of things, chairs. Boss chair, as well as a work desk. These need to be processed.

Shang Wen spent an hour sketching out the drawings, and then went to the airship workshop with a large pile of drawings. It is the place where carpenters are most concentrated.

The drawings are handed over to those carpenters, and the rest is their own business. And Shangwen still has a lot of time.

Shangwen turned his attention to something else. Since you are in the airship workshop, you have to design something related to the airship.

Airships' inability to measure altitude has always been an important factor that plagues flight. Especially speed and altitude. The speed requires an airspeed tube. Airspeed tubes are also called pitot tubes, total pressure tubes, and total-static pressure tubes. It is a device that senses the total pressure (also called total pressure) and static pressure of the air flow, and transmits the measured pressure data to the air data computer and flight instruments. This kind of aerial device is mainly used to measure flight speed, but also has a variety of other functions. Current technology is not yet capable of developing such advanced airspeed tubes.

It consists of two concentric round tubes, the inner round tube is the total pressure tube and the outer casing tube is the hydrostatic pressure tube. The principle of measuring the speed of the airspeed tube is that when the airplane flies forward, the airflow rushes into the airspeed tube, and the sensor at the end of the tube will feel the impact force of the airflow, that is, the dynamic pressure. The faster the aircraft flies, the greater the dynamic pressure. If you compare the pressure of the air when it is stationary, i.e., the static pressure with the dynamic pressure, you can know how fast the air rushing in, that is, how fast the plane flies. The tool that compares the two pressures is a hollow round box with a corrugated surface made of two very thin pieces of metal on the top and bottom, called a diaphragm box. The box is hermetically sealed, but has a tube connected to the airspeed tube. If the speed of the aircraft is fast, the dynamic pressure will increase, the pressure in the cassette will increase, and the cassette will bulge. The deformation of the diaphragm cassette can be measured by a device consisting of a small lever and gears and displayed with a pointer, which is the simplest airspeed of an airplane.

The speed measured by the airspeed tube is not the actual speed of the aircraft relative to the ground, but only the speed relative to the atmosphere, so it is called airspeed. If there is wind, the speed of the aircraft relative to the ground (called ground speed) should also be added to the wind speed (flying downwind) or subtracted (flying against the wind). In addition, the principle of airspeed tube velocity measurement uses dynamic pressure, which is related to atmospheric density. With the same relative air velocity, if the atmospheric density is low, the dynamic pressure is small, and the deformation of the diaphragm box in the airspeed gauge is corrected so that the same airspeed is corrected, and the indicated value at high altitude is higher than that at low altitude, and this airspeed is generally called "gauge velocity". Modern airspeedometers have two hands, one thinner and the other wider. The wide hand indicates the "gauge speed", while the thin one indicates the airspeed equivalent to the atmospheric pressure on the ground after various corrections, which is called the "real speed".

In order to prevent the small hole at the front end of the airspeed tube from icing and clogging during flight, the airspeed tube on the general aircraft has an electric heating device.

And the cassette becomes the key. In addition, it is an instrument that measures and indicates the vertical distance of the aircraft from a selected horizontal datum, which is called an altimeter.

The altimeter installed on the cockpit instrument panel of an aircraft usually includes a barometric altimeter and a radio altimeter. A barometric altimeter is actually a barometer that indirectly measures the flight altitude by measuring the atmospheric pressure at the altitude at which the aircraft is located. The radio altimeter is actually a ranging radar that takes the ground (water surface) as the detection target, and the altitude it indicates is the real altitude.

Ultra-modern altimeters could not be manufactured either. But something else can. That's the barometer.

An instrument built on the basis of Torricelli's experimental principle for measuring atmospheric pressure. The types of barometers include mercury barometers and aneroid barometers. Its uses are: to predict changes in the weather, when the air pressure is high, the weather is clear; When the air pressure drops, there will be stormy weather. Measurable height. For every 12 meters of elevation, the mercury column is lowered by about 1 millimetre, so that the height of the mountain and the altitude of the aircraft as it is in the air can be measured.

It can also predict changes in the weather, and the weather is sunny when the air pressure is high; When the air pressure drops, there will be stormy weather.

A device that uses a Torricelli tube to measure atmospheric pressure. The mercury tank at the bottom of the glass tube is replaced by a skin pouch with an adjustable ivory needle to indicate the mercury surface, called a "Fortin-style mercury barometer", and a metal sheath is added to the outside of the glass tube, and a scale is engraved on the sleeve to measure the height of the mercury column. An ivory needle is placed on top of the mercury tank, the tip of which is exactly at the zero point of the scale outside the tube, and a leather bag is used as the bottom of the mercury tank. When using, gently turn the spiral under the leather bag so that the mercury surface in the tank is in contact with the tip of the ivory needle (i.e., on a horizontal line with the zero point of the scale), and then read the height of the mercury column from the scale on the tube. This altitude, which is the magnitude of the local atmospheric pressure at that time. In addition, there are barometers for observation stations that do not require the need to align ivory needles, barometers for measuring low-pressure mountains, and barometers for navigation that are not sensitive to the rocking of ships.

The height of the mercury column supported by different atmospheric pressure is different, according to P=p (mercury density) hg, the calculated pressure is equal to the atmospheric pressure, of course, this calculation makes the barometer calculated and marked on the barometer, and the scale of the mercury face can be known by the size of the barometer!

However, the questions all point to one problem in the end. Processing of glass tubing. As well as a large amount of raw materials.

A very complex logical reasoning. Barometers require glass. Sodium carbonate is required for glass. What to do with sodium carbonate?