The telegraph (ancient Greek τῆλε - “far away” + γράφω - “I am writing”) in the modern sense is a means of transmitting a signal over wires, radio or other channels. The transmission of information by telegraph is called telegraphy.
Primitive types of communication
From time immemorial, mankind has used various primitive types of signaling and communication in order to transmit important information ultra-fast in cases where, for a number of reasons, traditional types of mail messages could not be used. Fires lit on elevated areas of the terrain, or smoke from bonfires, were supposed to notify of the approach of enemies or of an impending natural disaster. This method is still used by those who get lost in the taiga or by tourists experiencing natural disasters. Some tribes and peoples used for these purposes certain combinations of sound signals from percussion (for example, talking and other drums) and wind (hunting horn) musical instruments, others learned to transmit certain messages by manipulating reflected sunlight using a system of mirrors. In the latter case, the communication system was named "heliograph", which is a primitive light telegraph.
In 1792, in France, Claude Chappe created a system for transmitting information using a light signal. It was called "optical telegraph". Usually this type of telegraph is used on ships. In its simplest form, it was a chain of typical buildings located within sight of each other. On the roof of the buildings there were poles with movable crossbars - semaphores. Semaphores with the help of cables were controlled by operators who sat inside.
Schapp created a special code table, where each letter of the alphabet corresponded to a certain figure formed by a semaphore, depending on the position of the transverse bars relative to the support pole. The Chappe system allowed messages to be transmitted at a speed of two words per minute and quickly spread throughout Europe. In Sweden, a chain of optical telegraph stations operated until 1880.
Semaphores could transmit information with greater accuracy than smoke signals and beacons. In addition, they did not consume fuel. Messages