There have been many dynasties in China's history of more than 5,000 years. Naturally, some unique spy tools have been handed down. The more famous ones are the listening urn, flying kite, anti-cutting code and alum. There are four types of water. The most primitive eavesdropping device in ancient times, the listening urn
The listening urn was invented 2,500 years ago. There are detailed records on the manufacturing and use methods of the listening urn in "Mozi·Bei Xue". The listening urn was originally just a jar with a large mouth and a small belly. The user only needed to bury it in the ground and cover the mouth of the urn with a thin layer of leather. By leaning on it with one ear, the user could listen to the surrounding sounds. . Since the hearing of blind people is often better than that of ordinary people, some blind people are trained to perform listening tasks.
With the development of the times, listening urns are also in the process of continuous improvement. Regarding the later improved listening urn, there are relevant records in Shen Kuo's "Mengxi Bi Tan·Usage". At that time, the listening urn was called a yafu and was made of cowhide. Every scout would be equipped with this tool. Whenever the scouts perform eavesdropping missions, they will first take out arrows, blow out the arrows and put them under the pillow, so that the sounds of people and horses within a few miles can be heard. As for the Yafu at that time, it was invented based on the principle of cavity receiving sound. Kite, an ancient tool for transmitting information
Kite wind originated in the Spring and Autumn Period of the Eastern Zhou Dynasty and has a history of more than 2,000 years. According to legend, in the Spring and Autumn Period, a man named Mo Zhai spent three years making wooden birds from wood. The "Book" says: "Gongshu Ban made wooden kites to get a glimpse of the Song Dynasty." This is the earliest record of human use of kites. records. He later passed the kite-making business to his student Lu Ban. There is a record in "Mozi Lu Wen Chapter" that Lu Ban made a magpie shape out of bamboo based on the ideals and designs of his master Mo Zhai, which he called "Muzi". Magpie", this thing once flew in the air for three days.
It was not until Cai Lun improved papermaking during the Eastern Han Dynasty that he began to use paper to make kites, which were called "paper kites". As for kites, they began to be used as a tool to convey information during the Northern and Southern Dynasties. The earliest Morse code anti-cut code in ancient times
The anti-cut code evolved based on the anti-cut phonetic notation method invented by Qi Jiguang in the late Eastern Han Dynasty. Its principle is exactly the same as the design principle of modern cipher codes. The so-called fanqie phonetic notation method is to use two characters to phoneticize another character, take the initial consonant of the upper character and the final rhyme of the lower character, and recombine them into the pronunciation of the other character. When Qi Jiguang was fighting against the Japanese, he specially compiled two poems as a "code book". This should be China's earliest Morse code. The most mysterious secret writing technique in ancient times, alum water
Due to the inconvenience of transportation in ancient China, it was not safe to write some important things in letters, so the "secret writing technique" was invented for carrying out activities. Intelligence research work. The so-called "secret writing" is actually alum water that is common in people's lives. Because writing on a letter using alum water is impossible to read with the human eye after it dries. Once the letter is immersed in water, the handwriting written in alum water becomes visible. This is actually the use of simple chemical principles and the unique chemical properties of alum water. But this kind of thing was a very remarkable discovery in ancient times when technology was underdeveloped, and it has always been an important tool for spies.