Telegraphs have played a big role in the formation of modern society. The slow and unreliable transfer of information slowed down progress, and people were looking for ways to speed it up. With the invention of electricity, it became possible to create devices that instantly transmit important data over long distances.
At the dawn of history
Telegraph in different incarnations is the oldest form of communication. Even in ancient times, it became necessary to transmit information at a distance. So, in Africa, tom-tom drums were used to transmit various messages, in Europe - a fire, and later - a semaphore connection. The first semaphore telegraph was first called "tachygraph" - "cursive writer", but then it was replaced by the name "telegraph" - "long-range writer" more appropriate for its purpose.
First apparatus
With the discovery of the phenomenon of "electricity" and especially after the remarkable research of the Danish scientist Hans Christian Oersted (the founder of the theory of electromagnetism) and the Italian scientist Alessandro Volta - the creator of the first galvanic cell andthe first battery (it was then called the "voltaic column") - many ideas appeared for creating an electromagnetic telegraph.
Attempts to manufacture electrical devices that transmit certain signals over a certain distance have been made since the end of the 18th century. In 1774, the simplest telegraph apparatus was built in Switzerland (Geneva) by the scientist and inventor Lesage. He connected two transceivers with 24 insulated wires. When an impulse was applied by an electric machine to one of the wires of the first device, the elder ball of the corresponding electroscope was deflected on the second. Then the technology was improved by the researcher Lomon (1787), who replaced 24 wires with one. However, this system can hardly be called a telegraph.
Telegraph machines continued to improve. For example, the French physicist André Marie Ampère created a transmission device consisting of 25 magnetic needles suspended from axes and 50 wires. True, the bulkiness of the device made such a device practically unusable.
Schilling Apparatus
Russian (Soviet) textbooks indicate that the first telegraph machine, which differed from its predecessors in efficiency, simplicity and reliability, was designed in Russia by Pavel Lvovich Schilling in 1832. Naturally, some countries dispute this statement, "promoting" their equally talented scientists.
The works of P. L. Schilling (many of them, unfortunately, were never published) in the field of telegraphy contain a lotinteresting projects of electric telegraph apparatuses. Baron Schilling's device was equipped with keys that switched the electric current in the wires connecting the transmitting and receiving apparatus.
The world's first telegram, consisting of 10 words, was transmitted on October 21, 1832 from a telegraph machine installed in the apartment of Pavel Lvovich Schilling. The inventor also developed a project for laying a cable to connect telegraph sets along the bottom of the Gulf of Finland between Peterhof and Kronstadt.
Scheme of telegraph machine
The receiving apparatus consisted of coils, each of which was included in the connecting wires, and magnetic arrows suspended above the coils on threads. On the same threads, one circle was strengthened, painted black on one side and white on the other. When the transmitter key was pressed, the magnetic needle above the coil deviated and moved the circle to the appropriate position. According to the combinations of the arrangements of the circles, the telegraph operator at the reception, using a special alphabet (code), determined the transmitted sign.
At first, eight wires were required for communication, then their number was reduced to two. For the operation of such a telegraph apparatus, P. L. Schilling developed a special code. All subsequent inventors in the field of telegraphy used the principles of transmission coding.
Other developments
Almost simultaneously, telegraph machines of a similar design, using the induction of currents, were developed by the German scientists Weber and Gaus. As early as 1833 they laid a telegraph line in GöttingenUniversity (Lower Saxony) between the astronomical and magnetic observatories.
It is known for certain that Schilling's apparatus served as a prototype for the telegraph of the British Cook and Winston. Cook got acquainted with the works of the Russian inventor at the University of Heidelberg (Germany). Together with colleague Winston, they improved the apparatus and patented it. The device enjoyed great commercial success in Europe.
Steingel made a small revolution in 1838. Not only did he run the first telegraph line over a long distance (5 km), he also accidentally made the discovery that only one wire can be used to transmit signals (grounding plays the role of the second).
Morse telegraph machine
However, all the listed devices with dial indicators and magnetic arrows had an irreparable flaw - they could not be stabilized: errors occurred during fast transmission of information, and the text was distorted. The American artist and inventor Samuel Morse managed to complete the work on creating a simple and reliable telegraph communication scheme with two wires. He developed and applied the telegraph code, in which each letter of the alphabet was indicated by certain combinations of dots and dashes.
The Morse telegraph machine is very simple. A key (manipulator) is used to close and interrupt the current. It consists of a lever made of metal, the axis of which communicates with a linear wire. One end of the manipulator lever is pressed against a metal ledge by a spring,connected by wire to the receiving device and to ground (grounding is used). When the telegraph operator presses the other end of the lever, it touches another ledge connected by a wire to the battery. At this point, the current rushes along the line to a receiving device located elsewhere.
At the receiving station, a narrow strip of paper is wound on a special drum, continuously moved by a clock mechanism. Under the influence of the incoming current, the electromagnet attracts an iron rod, which pierces the paper, thereby forming a sequence of characters.
Inventions of Academician Jacobi
Russian scientist, academician B. S. Yakobi in the period from 1839 to 1850 created several types of telegraph devices: writing, pointer synchronous-in-phase action and the world's first direct-printing telegraph device. The latest invention has become a new milestone in the development of communication systems. Agree, it is much more convenient to immediately read the sent telegram than to spend time decoding it.
Jacobi's direct-printing machine consisted of a dial with an arrow and a contact drum. On the outer circle of the dial, letters and numbers were applied. The receiving apparatus had a dial with an arrow, and in addition, it advanced and printed electromagnets and a typical wheel. All letters and numbers were engraved on the type wheel. When the transmitting device was started up, from the current pulses coming from the line, the printing electromagnet of the receiving device worked, pressed the paper tape against the standard wheel and printed on paperaccepted sign.
Yuz Apparatus
American inventor David Edward Hughes approved the method of synchronous operation in telegraphy by constructing in 1855 a direct-printing telegraph apparatus with a typical continuous rotation wheel. The transmitter of this machine was a piano-style keyboard, with 28 white and black keys, which were printed with letters and numbers.
In 1865, Yuz's devices were installed to organize telegraph communications between St. Petersburg and Moscow, then spread throughout Russia. These devices were widely used until the 30s of the XX century.
Bodo Apparatus
Yuz's apparatus could not provide high speed telegraphy and efficient use of the communication line. Therefore, these devices were replaced by multiple telegraph devices, designed in 1874 by the French engineer Georges Emile Baudot.
The Bodo apparatus allows several telegraphers to simultaneously transmit several telegrams in both directions on one line. The device contains a distributor and several transmitting and receiving devices. The transmitter keypad consists of five keys. To increase the efficiency of using the communication line in the Baudot apparatus, a transmitter device is used in which the transmitted information is coded manually by the telegrapher.
Operation principle
The transmitting device (keyboard) of the device of one station is automatically connected through the line for short periods of time to the corresponding receiving devices. Their orderthe connections and the accuracy of the coincidence of the moments of switching on are provided by the distributors. The pace of work of the telegraphist must coincide with the work of distributors. The brushes of the transmission and reception distributors must rotate synchronously and in phase. Depending on the number of transmitting and receiving devices connected to the distributor, the productivity of the Bodo telegraph machine varies between 2500-5000 words per hour.
The first Bodo devices were installed on the telegraph connection "Petersburg - Moscow" in 1904. Subsequently, these devices became widespread in the telegraph network of the USSR and were used until the 50s.
Start-stop apparatus
Start-stop telegraph marked a new stage in the development of telegraph technology. The device is small and easy to operate. It was the first to use a typewriter-style keyboard. These advantages led to the fact that by the end of the 50s, Bodo devices were completely ousted from telegraph offices.
A great contribution to the development of domestic start-stop devices was made by A. F. Shorin and L. I. Treml, according to the development of which, in 1929, the domestic industry began to produce new telegraph systems. Since 1935, the production of devices of the ST-35 model began, in the 1960s an automatic transmitter (transmitter) and an automatic receiver (reperforator) were developed for them.
Encoding
Since the ST-35 devices were used for telegraph communication in parallel with the Bodo devices, they hada special code No. 1 was developed, which differed from the generally accepted international code for start-stop devices (code No. 2).
After the decommissioning of Bodo machines, there was no need to use a non-standard start-stop code in our country, and the entire existing ST-35 fleet was transferred to international code No. 2. The devices themselves, both modernized and new designs, were named ST-2M and STA-2M (with automation attachments).
Roll machines
Further developments in the USSR were incited to create a highly efficient roll telegraph machine. Its peculiarity is that the text is printed line by line on a wide sheet of paper, like a matrix printer. High performance and the ability to transmit large amounts of information were important not so much for ordinary citizens as for business entities and government agencies.
- Roll telegraph T-63 is equipped with three registers: Latin, Russian and digital. With the help of punched tape, it can automatically receive and transmit data. Printing takes place on a roll of paper 210 mm wide.
- Automated roll-to-roll electronic telegraph RTA-80 allows you to dial manually and automatically send and receive correspondence.
- The RTM-51 and RTA-50-2 devices use a 13 mm ink ribbon and roll paper of standard width (215 mm) to register messages. The machine prints up to 430 characters per minute.
Recent Times
Telegraph sets, photos of which can be found on the pages of publications and in museum expositions, played a significant role in accelerating progress. Despite the rapid development of telephone communications, these devices did not go into oblivion, but evolved into modern faxes and more advanced electronic telegraphs.
Officially, the last wire telegraph operating in the Indian state of Goa was closed on July 14, 2014. Despite the huge demand (5000 telegrams daily), the service was unprofitable. In the US, the last telegraph company, Western Union, ceased its direct functions in 2006, concentrating on money transfers. Meanwhile, the era of telegraphs has not ended, but moved to the electronic environment. The Central Telegraph of Russia, although it has significantly reduced its staff, still fulfills its duties, since not every village on a vast territory has the opportunity to install a telephone line and the Internet.
In the newest period, telegraph communication was carried out through frequency telegraphy channels, organized mainly through cable and radio relay communication lines. The main advantage of frequency telegraphy was that it allows organizing from 17 to 44 telegraph channels in one standard telephone channel. In addition, frequency telegraphy makes it possible to communicate over almost any distance. The communication network, made up of frequency telegraphy channels, is easy to maintain and also has the flexibility that allows you to create bypass directions in case of failure of the main line facilities.directions. Frequency telegraphy has proven to be so convenient, economical and reliable that DC telegraph channels are now used less and less.
