We explain what the telegraph is, how it works and why it was so important. In addition, we tell you its history and what Morse code is.

Telegraphy was the first form of electrical communication in history.

What is the telegraph?

The Telegraph It is a device that allows the transmission of information at a distance, using electrical signals. transmitted through wires or radio waves, and a coding system, such as Morse code, that allows these signals to be translated into words. Telegraphy, created between the 18th and 19th centuries, was the first form of electrical communication in history.

In principle, different forms of telegraphy existed over time, but the term “telegraph” is reserved for the electrical telegraph, an invention of the mid-19th century that constituted for almost 100 years the main form of distance communication in the world.

For its part, the term “telegraph” is made up of the Greek words TV (“distance”, “far”) and graphos (“writing”). It was initially used in the 18th century to name an optical communication system developed in France, which operated through light towers in the manner of traffic lights.

The telegraph revolutionized the methods used at the time to communicate over long distances, led to a great expansion of electrical wiring in the main industrialized nations and inaugurated a specialized labor sector (telegraph operators) around this type of device and electricity. (electrical engineers). It was one of the great inventions associated with the Industrial Revolution of the 19th century..

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The invention of the telegraph

The invention of the telegraph occurred thanks to the accumulation of scientific and technological knowledge that took place in Europe and the United States between the 18th and 19th centuries, especially in the area of ​​electricity. Particularly important were the previous contributions of the Italian scientist Alessandro Volta (1745-1827), the British Michel Faraday (1791-1867) and the American Joseph Henry (1797-1878).

The actual idea of ​​telegraphic communication was the brainchild of the French mathematician and physicist André-Marie Ampère. (1775-1836), who tried to create a system for the transmission of electrical impulses using a series of galvanometers, but without being able to overcome the 61 meter distance barrier. It took the invention of the electromagnet and relay in the 1830s for Joseph Henry to create an improved version for use on long cable runs.

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At the same time, in tsarist Russia, Russian diplomat and scientist Pavel Schilling (1786-1837) invented a telegraph that operated with a keyboard similar to that of a piano, and with which he managed to transmit electrical impulses along a cable of 5 km distance. This invention prompted the first experimental underground and submarine wiring in Russia, but the project was abandoned in 1837 after the scientist’s death.

Other attempts to build a telegraph were carried out by the Germans Carl Friedrich Gauss (1777-1855) and Wilhelm Eduard Weber (1804-1891), who installed a 1,200-meter power line over the roofs of the city of Göttingen and managed to transmit the electricity from the university where they worked to the city’s astronomical observatory. On his side, on the other side of the Atlantic, the American David Alter (1807-1881) had similar experiences in Elderton, Pennsylvania, a year before Samuel Morse patented his famous electric telegraph.

It was after 1836 that the American Samuel Morse (1791-1872) designed an artifact that, among other things, consisted of an electrified pencilable to paint on an easel a straight line in the absence of electric current and a wavy line when there was current.

But after improving the device in collaboration with his colleague Alfred Vail (1807-1859), Morse finally devised a system of graphic representation that through points and lines could reflect electrical impulses and be translated into letters. The famous morse code was born that way.

On May 24, 1844, Morse and Vail achieved a public demonstration of their telegraph system., sending a first message from Washington, DC, to the B&O Railroad in Baltimore. This first message consisted of “What hath God wrought?” (“What has God brought us?”), from the Biblical Old Testament Book of Numbers.

Thereafter, the Morse-Vail telegraph was a resounding success in the following decadesand served as inspiration for future telegraphs developed throughout the 19th century, and whose final point was the invention and popularization of the teletype at the beginning of the 20th century.

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How does the telegraph work?

The general operation of the electric telegraph requires:

  • an emitting artifact that emits electrical pulses.
  • A receiving artifactwhich receives them.

For this to happen, the transmitter has a switch (called a “manipulator”), which, when closed, allows the flow of current from an electric battery to the transmission line (wired or wireless) and the electromagnet on the other side. The latter, when activated, attracts a metallic piece finished in a punch, in such a way that the paper slides over a roller and dots and lines are made thanks to the movement of a cylinder full of ink.

A) Yes, the duration of pressing the switch on the emitter results in the continuity of a line on the other side: if pressed quickly, a point is drawn; a longer press draws a line. A set of these symbols can later be translated into alphanumeric characters to obtain a short message.

importance of the telegraph

telegraph importance
The telegraph made it possible to overcome borders and inaugurate instantaneous communication.

The telegraph was a revolutionary invention in the 19th century, which allowed for the first time in history reciprocal, fast and efficient communication over long distances. The ability to send and receive messages quickly, with almost no return delay, allowed coordination of resources over great distances, which was key to international trade and the transfer of goods, especially through trains and ships.

This also made it possible to bring the different regions of the countries closer together, to overcome borders and to inaugurate instantaneous communication: a person could report an emergency and receive an immediate response, which would have been impossible by postal mail.

The ability to send messages without delay and 24 hours a day provided greater independence and efficiency to the military sector, since the intelligence could be sent quickly to the leadership of the army. This in turn made the telegraph offices an important military target during the conflicts of the 20th century.

Finally, the popularization of the telegraph reaffirmed the importance of electricity and electrical engineering in the modern world, and paved the way for new forms of technologyboth in the telecommunications sector and in other areas of engineering and physics.

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morse code

morse code telegraph
The Morse code owes its name to its inventor, the American Samuel Morse.

The morse code owes its name to its inventor, the American Samuel Morse, and it arose as a formal language for the transmission of electrical impulses, which distinguishes between two fundamental signs: the period (.) and the line (-), each of which corresponds to a range of electrical impulse duration: short and long. Thus, by recognizing the duration of the transmitted impulse, telegraphy devices could receive coded messages that were later translated into verbal language.

For the latter, the Morse code has an alphabet: each letter and number corresponds to a specific combination of short and long impulses, as follows:

A . – (point, line) 1 . – – – – (dot, line, line, line, line)

B. – . . . (line, point, point, point) 2 . .- – – (dot, dot, line, line, line)

C. – . -. (line, dot, line, dot) 3 . . . – – (dot, dot, dot, line, line)

D. – . . (line, point, point) 4 …. – (dot, dot, dot, dot, line)

AND . (dot) 5 ….. (dot, dot, dot, dot, dot)

In this way, a message like “EVERY 1” (that is, “every one”) can be translated into Morse code as follows: -.-. .- -.. .- .—-.

More in: Morse code

the end of telegraphy

end telegraph india
BSNL used the latest telegraph network until 2013, and today offers mobile phone services.

Telegraphy was in vogue throughout the world until the end of the 20th century, when it was displaced by more effective and simple communication mechanisms. The invention in 1985 of mobile text messaging and later internet messaging made telegraphy completely obsolete. The last telegraph network in the world was shut down in 2013: the Indian state-owned company Bharat Sanchar Nigam Limited. However, telegraphy had been used in a minority for decades.

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  • “Telegraph” on Wikipedia.
  • “Etymology of Telegraph” in the Online Spanish Etymological Dictionary.
  • “How the telegraph revolutionized communications” (video) in Deutsche Welle in Spanish.
  • “Finds and creations: The telegraph” (video) at UNED.
  • “The telegraph” in ILCE Digital Library (Mexico).
  • “Telegraph” in The Encyclopaedia Britannica.