Let’s talk about the principle of telegraph

Principle: Telegraph information is sent in the form of electrical signals through dedicated switching lines. The signals use codes to replace letters and numbers. The commonly used code is Morse code. Now, with the popularization of telephones, faxes, etc., telegraphs are rarely used.

European scientists gradually discovered various properties of electricity in the 18th century. At the same time, some people began to study the possibility of using electricity to transmit messages. As early as 1753, a British man proposed using static electricity to send telegraphs. His idea was to use 26 wires to represent the 26 English letters. The party sending the telegram applies static electricity to the wire in the order of the text. The receiving party connects small pieces of paper to each wire. When the paper is lifted up by static electricity, the text can be transcribed. Extended information

The invention of the telegraph kicked off the telecommunications era and created the history of human beings using electricity to transmit information. China secretly opened the telegraph in Shanghai in 1871, and Li Hongzhang built the first telegraph on the mainland in 1879. A military telegraph line was opened, and then the Tianjin-Shanghai telegraph line was opened, and the General Telegraph Bureau was established in Tianjin.

The telegraph is a type of communication service. It was invented in the early 19th century and was the earliest method of using electricity for communication. The telegraph greatly accelerated the circulation of news and was one of the important inventions of industrial society. Early telegraphs could only communicate on land. Later, submarine cables were used to carry out transoceanic services. By the beginning of the 20th century, wireless telegraphs began to be used, and telegraph services could basically reach most areas on the earth. Telegraph is mainly used to transmit text messages. The use of telegraph technology to transmit pictures is called fax.

Reference: Baidu Encyclopedia-Telegram