TELEGRAPH: HISTORY, INVENTION, EVOLUTION, HOW IT WORKS - TECHNOLOGY - 2025

The telegraph consisted of a device that transmitted coded messages through electrical signals. To do this, he used radio communications or wire lines. This device is considered the first means of electrical communication and its use was very important during the warfare.

For some prominent authors such as Alexandre Théophile Vandermonde (1735-1796), the invention of the telegraph symbolized a democratizing revolution. This conception was due to the fact that the device could communicate to many people over great distances, which allowed each one to express their wishes and opinions.

The telegraph consisted of a device that transmitted coded messages through electrical signals. Source: Cliff from I now live in Arlington, VA (public domain).

However, the well-known sociologist Armand Mattelart (1936) denied this conception. The author claimed that the telegraph did not have a true democratizing approach because it generally employed encrypted code. In addition, the State denied the open and free use of the device to citizens in order to maintain internal security.

As of 1985, the telegraph began to lose importance as a means of communication. This was due to the fact that short message services were introduced during this period. In addition, the use of email and mobile telephony was eventually established. This resulted in the closure of the telegraphic services of companies such as Western Union.

Despite this, the telegraph stood out as a form of communication for more than a century (from the late 18th century to the late 20th century) and contributed to later advances in wireless connections. The last company to provide telegraph services was India Bharat Sanchar Nigam Limited, which closed this product in 2013.

History and invention

Since the origins of humanity, man has had the need to communicate remotely quickly, either to prevent attacks or to know the consequences and development of battles.

Previously, the available medium consisted only of light and sound, which could only be perceived by hearing and sight. Therefore, societies used fire at night and smoke during the day to send a message.

Consequently, the information transmitted was very brief. Only allowed to confirm events, so it was not possible to communicate the circumstances in which a particular event had developed.

For example, in the tragedy Agamemnon (458 BC) written by Aeschylus, it is narrated how the wife of the conqueror learned of the fall of Troy that same night thanks to a bonfire lit by a traveler over several mountains until reaching to the palace where the woman resided.

The importance of electricity

In 1753, the first proposal for what could be an electric telegraph was published. This article was published by Scots Magazine and it explained how a set of threads, stretched horizontally between two places, could be used to convey a message. This post was simply signed CM

Later, George Louis Lesage proposed in 1774 a plan similar to that of CM. However, the threads had to be underground, so the author established that they had to be inserted in a ceramic tube that had divisions for each of the threads; this would avoid the influence of atmospheric electricity.

Two years later, Charles Agustín de Coulomb invented a torsion balance. This experiment made it possible to accurately measure the force of electric charges, proving that this force was proportional to the individual charges, while it was inversely proportional to the distance that separated them.

Thanks to this principle, in 1787 Lomond suggested a system that used a single wire where the letters were identified by the displacement produced by the different electrical forces that were sent.

After this, other personalities such as Luigi Galvani and Dr. Francisco Salvá proposed telegraphs based on static electricity, however, all these models continued to have the disadvantage of atmospheric influence.

Optical telegraphy

The revolution in France had a notable influence on the creation of regular telegraphy. This was due to the fact that the French could not coordinate their allied forces because of the lack of communication between them.

Consequently, in 1790 Claude Chappe together with his brothers began to design a communication system that would satisfy the needs of the French nation. By then, attempts at electrical telegraphs had already been made, however, Chappe decided to go for optical telegraphy.

This telegraphy used the use of spyglasses to send messages, which were encoded. The images produced by the spyglasses could be visible at a maximum distance of twelve kilometers.

The railroad and the electric telegraph

In 1830, the first public railway ran, which connected Manchester to Liverpool. Its impact on communications was revolutionary, since it allowed people to move in the same time it took for information to arrive through the optical telegraph.

For this reason, it became essential to achieve a more efficient telegraph that also allowed to regulate rail traffic and notify the arrival of trains. This new phenomenon inspired Baron Schilling to introduce the use of five needles with the aim of passing electric current through the magnetized needle.

Schilling's telegraph was a step forward in the development of this apparatus. Following this, a series of needle telegraphs designed by prominent inventors such as William Fothergill Cooke were manufactured.

Evolution

Below is a brief chronology of the development of the telegraph:

Pavel Schilling (1786-1837)

As mentioned in previous paragraphs, Schilling was one of the forerunners in the development of the telegraph. In 1832, he built an electromagnetic telegraph, which consisted of a board of sixteen black and white keys which sent a series of characters.

On the other hand, the receiving apparatus consisted of six needles whose change of direction decoded the characters.

Johann Friedrich Gauss (1777-1855) and Wilhelm Eduard Weber (1804-1891)

In 1833, these two scientists and friends managed to install one of the first telegraph lines on the rooftops of the city of Göttingen (Germany). This line covered 1,200 meters and allowed the union of the astronomical observatory with the university of the city.

David Alter (1807-1881)

In 1836, the scientist David Alter built the first electric telegraph on the American continent; this was nicknamed with the name of Elderton.

Although the inventor confirmed its operation in front of a number of witnesses, this telegraph could never be turned into a practical device. Therefore, it was overshadowed by the Morse telegraph, which emerged on the same date.

Samuel Morse (1791-1872)

In 1836, Samuel Morse made a very stout but simple device: it was a pencil that drew in a straight line when there was no electrical flow. On the other hand, when there was an electric current the pencil - connected to a pendulum - formed a line.

After some adjustments, Morse was able to create the famous code that bears his name with the help of machinist Alfred Vail. Morse code is a binary system that forms characters through three symbols: space, period, and dash.

Samuel Morse Telegraph. Source: Museum of Commerce and Industry (public domain).

David Edward Hughes (1831-1900)

In 1856, Hughes built a telegraph printing system. This device consisted of a twenty-eight key keyboard (with certain similarities to those of the typewriter), where each keystroke was equivalent to sending a signal that allowed a wheel to print the corresponding character.

Hughes was unable to market the invention in his country, as Morse obtained a patent for his telegraph. However, he managed to sell the idea to Carlos Luis Napoleón Bonaparte (known as Napoleon III).

This device had the peculiarity that it surpassed Samuel Morse's invention in terms of speed, since it transmitted up to sixty words in a minute, while Morse's only twenty-five.

Other Advances

By the 1850s, the telegraph had managed to spread throughout most of Europe and North America. However, the use of submarine lines had not yet been perfected, which broke when they reached the shores of the ocean.

Subsequently, a successful cable was laid across the Strait of Calais. This spurred scientists to build a network of submarine lines linking Africa to Europe, along with the intermediate set of islands.

How the telegraph works

The telegraph was a device that used electrical pulses to send coded messages through a cable to a receiver, which decoded the message.

The telegraph could not transmit other data or voices; it only used the coded pulses to send the content. The most famous coding system used by telegraphs was that designed by Samuel Morse.

Operation of the morse code telegraph

Generally, Morse telegraphs had a lever that connected two stacks placed at a short distance.

Likewise, the fulcrum of said lever was connected to the line that conducted the pulsations. When the lever was pressed briefly, the current from the batteries marked a point; On the other hand, if the pressure was longer, a line was marked.

References

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2. Gilbert, E. (1969) How Good is morse code? Retrieved on November 15, 2019 from core.ac.uk
3. Olivé, S. (2013) Telegraphs: a story of its centennial journey. Retrieved on November 15, 2019 from Fundación Telefónica.
4. Romeo, J; Romero, R. (sf) The railway and the telegraph. Retrieved on November 15, 2019 from Telefónica Foundation: docutren.com
5. SA (sf) Telegraph. Retrieved on November 15, 2019 from Wikipedia: es.wikipedia.org
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7. Thomas, L. (1950) Morse code printing system. Retrieved on November 15, 2019 from Googe patents.