Shulou(Shulou.com)11/24 Report--

Among the climatic factors, humidity is an important indicator. Thousands of years ago, the dryness and wetness in the air was not expressed in terms of scale and percentage. People's perception is that the lower the humidity, the drier the air, and the higher the humidity, the wetter the air.

Too many ancient poems leave the humidity in people's daily life bit by bit. As early as the Western Jin Dynasty, Fu Xuan published a poem of inflammation and drought, in which "dust rises in the river and there is no grass in the wild field" writes about the dryness of the air and the seriousness of the drought. In the poem "Meiyu" by Mei Yaochen in the Song Dynasty, there are "withered hedges caused by wet bacteria, moisturizing qi and plain clothes."

Among them, "moisturizing" is moisture and moisture. On the other hand, Guo Xiangzheng, a poet of the Northern Song Dynasty, has "the roof leaks along the window jade seal and lives in the years of steaming humidity." In the Ming Dynasty, Ren Huan wrote in "where are the ants in the burrow of Cheng Huang Ting in Shangjiading?" where are the ants in the courtyard, but the swallow in the sky does not come. Just when the foundation is wet, you can see the moon platform. Sweat turned into rain, hard work has turned to dust. He should look at the worship, sprinkle a moist moss. "

Air humidity is invisible to the naked eye, although everyone can feel it, and even feel everything, but how to roughly evaluate the size of air humidity, people have been trying to measure air humidity since ancient times.

China is probably the first country to invent the humidity measuring instrument. The Book of Heavenly officials in Shiji once mentioned an instrument that hung soil and charcoal on both sides of the balance to observe the rise and fall of the balance at one end. This is actually the original "hygrometer".

Its principle is: when the weather is dry, the charcoal is light, the balance tends to the soil; when the weather is wet, the charcoal is heavy, and the balance tends to charcoal, which is what the ancients said, "dry leads to light charcoal, wet leads to heavy charcoal". The motto of the Thai nationality, the son of Huainan, said: "the husband is so wet that he does not see its shape, but the charcoal is already heavy." When the moisture comes, people can't see it, but the charcoal is already heavy. This further illustrates that this hygrometer can judge the invisible water vapor content.

In addition to the hanging carbon balance, another humidity measuring device appeared earlier. Wang Chong of the Eastern Han Dynasty once said in "on the changes of Heng" that when the strings become loose, it will rain. The loosening of the strings is caused by the humidity of the air and the elongation of the strings, indicating that the air is more humid. Thus it can be seen that the ancient harp can also be used as the original equipment for measuring air humidity, which is basically consistent with the concept of "hair" in modern hair hygrometers.

Guqin first appeared in the Zhou Dynasty, and the earliest written records of Guqin can be found in the Book of songs. The Book of songs collects poems from the early Western Zhou Dynasty to the middle of the Spring and Autumn period (11th century to 6th century), reflecting the social situation of about 500 years from the early Zhou Dynasty to the late Zhou Dynasty. During the Spring and Autumn and warring States period, the story of finding a bosom friend in Boya and Zi period became a good story about Guqin.

In his book the five elements of the Tian Family in the late Yuan and early Ming Dynasty, Lou Yuanli also said, "if the harp and strings are very harmonious, then the way of heaven must be a little shapeless at a glance; if it is uneven, it will change, and the cover will also be caused by the climate." if the noble string is suddenly wide, it will be due to the wetting of the piano bed, which will lead to overcast and rain. " The main idea is that the dry clean string of good quality suddenly becomes wider because of the dampness of the piano bed, which indicates that it will be cloudy and rainy.

He also said that if the tone produced by the strings is not properly tuned, it also indicates cloudy and rainy weather, which is actually due to the decrease in pitch sensitivity of the broadened strings. Thus it can be seen that during the Qin and Han dynasties, people had an accurate understanding of air humidity, and the change of air humidity was evaluated by the change of strings.

During the reign of Emperor Kangxi in the Qing Dynasty, Ferdinand Verbiest, a western missionary who came to China, made a string hygrometer out of deer tendons to test the dryness and humidity in the air. Its principle is also "deer tendon moisture absorption".

Both strings and deer tendons are very close to the "hair" principle of modern hair hygrometers. The change in the length of the string caused by the change of humidity is very small and difficult to detect, but the change in the pitch of the string is very obvious. It can be said that the basic principle of suspension hygrometer has been conceived here.

Whale bone dispute the world's earliest hygrometer, the name "hanging charcoal" or "string" still needs to be considered, but they are more than 1000 earlier than similar humidity instruments in Europe. On the other side of the ocean, there is a well-known "whale bone dispute" about hygrometers, which is a scientific debate about where the "earliest" hygrometers are named in Europe.

Early humidity measuring devices used human or animal hair to maintain a certain degree of tension. Hair is hygroscopic (retaining moisture); its length varies with humidity, and the change in length may be magnified by a mechanism and displayed on the dial or scale. In the late 17th century, the device was called a hygroscopic mirror by some scientists, and the term is no longer in use. Whale bones and other materials can be used instead of hair.

In 1783, Horace Benedict de Saussure, a Swiss physicist and geologist, made the first hair tension hygrometer using human hair (pictured below) and is believed to be the inventor of such a hygrometer.

It consists of an 8'10 inch long human hair with a pulley device. One end of the hair is fixed to the screw a, the other is fixed by the pulley c and is hung and tightened by silk thread and weight d. The pulley is connected to the indexer, which moves on the scale (e). Usually the hair is greased, such as soaking the hair in ether first, which can make the instrument more sensitive.

Another Jean-Andre de Luc (1727-1817) from Switzerland was a Swiss geologist, natural philosopher and meteorologist. He designed a portable barometer for geological surveys, which includes measurements of moisture, evaporation and indicators such as hygrometers and thermometers. In a paper published in the Proceedings of the Royal Society of Natural philosophy, he showed a new humidity device that resembles a mercury thermometer, which uses an ivory ball, thus expanding the moisture. It also caused a decline in mercury (mercury) (he advocated the use of mercury instead of alcohol in measuring devices). Drucker also gave the first correct rule for measuring height with the help of a barometer.

His other design was a whale bone hygrometer, which sparked a heated debate with Horace Benedict de Saussure, known as the "whale bone battle". Drucker thought he was the inventor of the hair hygrometer. His paper on humidity devices was published as early as 1773, and his second paper was published in 1791. His whale bone hygrometer is still preserved in a museum in Geneva.

The arguments among scientists represent their respective adherence to scientific ideas, and bring us more and more of their own inventions.

Wen Yuan: a Bird Flying early for thousands of years: science and Technology of Meteorological observation and Measurement in Ancient China. Author: Huang Wei Painter: Huang Ying Tong Wen Zhong picture originates from the original author. All rights belong to the original author. This article comes from Wechat official account: ID:tupydread, author: Huang Wei, painter: Huang Yatong, Editor: Zhang Runxin.

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