Telegraph
The telegraph is an apparatus or device that uses electrical signals to transmit encoded text messages, such as Morse code, over wire lines or radio communications. The electric telegraph replaced the semaphore optical signal transmission systems, such as those designed by Claude Chappe for the French army and Friedrich Clemens Gerke for the Prussian army, thus becoming the first form of electrical communication.
History of the telegraph
In 1746, the French scientist and priest Jean Antoine Nollet gathered approximately two hundred monks in a circle about a mile (1.6 km) in circumference, connecting them with pieces of iron wire. Nollet then discharged a battery of Leyden jars through the human chain and observed that each one reacted practically simultaneously to the electric discharge, thus demonstrating that the speed of propagation of electricity was very high.
In 1753, an anonymous contributor to Scots Magazine suggested an electrostatic telegraph. Using one conductive thread for each letter of the alphabet, a message could be transmitted by connecting the ends of the conductor in turn to an electrostatic machine, and observing the deflection of balls of pith at the receiving end. electrostatic attraction were the foundation of the first experiments in electrical telegraphy in Europe, but they were abandoned as impractical and never developed into a very useful communication system.
In 1800 Alessandro Volta invented the voltaic pile, which allowed the continuous supply of an electrical current for experimentation. This became a much less limited low-voltage current source than the momentary discharge from a Leyden jar electrostatic machine, which was the only known method until the advent of artificial sources of electricity.
Another early experiment in electrical telegraphy was the electrochemical telegraph created by German physician, anatomist and inventor Samuel Thomas von Sömmerring in 1809, based on a less robust 1804 design by Spanish polymath and scientist Francisco Salvá Campillo. Both designs used several conductors (up to 35) to represent almost all the Latin letters and numbers. Thus, messages could be transmitted electrically for up to a few kilometers (in von Sömmering's design), with each of the receiver's wires immersed in an individual glass tube filled with acid. An electric current was applied sequentially by the issuer through the different conductors that represented each character of a message; at the receiving end the currents electrolyzed the acid in the tubes in sequence, releasing streams of hydrogen bubbles alongside each received character. The operator of the telegraph receiver would observe the bubbles and could then record the transmitted message, albeit at a very low transmission speed. The main drawback of the system was the prohibitive cost of manufacturing the multiple conductive wire circuits it employed, unlike of the cable with a single conductor and ground return, used by later telegraphs.
In 1816, Francis Ronalds installed an experimental telegraphy system on the grounds of his home in Hammersmith, London. He had 12.9 km of high-voltage static-charged steel cable laid, suspended by a pair of strong wooden trusses with 19 bars each. Rotating indicators, operated by clockwork motors, which were engraved with numbers and letters of the alphabet, were attached to both ends of the cable.
The physicist Hans Christian Ørsted discovered in 1820 the deflection of a compass needle due to electric current. That year, the German physicist and chemist Johann Schweigger, based on this discovery, created the galvanometer, winding a coil of conductor around a compass, which could be used as an indicator of electrical current.
In 1821, the French mathematician and physicist André-Marie Ampère suggested a telegraph system based on a set of galvanometers, one for each transmitted character, with which he claimed to have experimented successfully. But in 1824, his British colleague Peter Barlow said that such a system could only work up to a distance of about 200 feet (61 m) and was therefore impractical.
In 1825, British physicist and inventor William Sturgeon invented the electromagnet, winding uninsulated conductive wire around a varnished iron horseshoe. American Joseph Henry improved on this invention in 1828 by placing several coils of insulated wire around an iron bar, creating a more powerful electromagnet. Three years later, Henry developed a system of electrical telegraphy that he improved in 1835 thanks to the relay that he invented, to be used through long cable runs, since this electromechanical device could react against weak electrical currents.
Schilling's Telegraph
For his part, the Russian scientist and diplomat Pavel Schilling, based on von Sömmering's invention, began to study electrical phenomena and their applications. Based on his knowledge, he created another electromagnetic telegraph in 1832, whose emitter was a board of 16 black and white keys, like those of a piano, which served to send the characters, while the receiver consisted of six galvanometers with needles suspended by silk threads whose deflections served as a visual indication of the characters sent. The signals were decoded into characters according to a table developed by the inventor. The telegraph stations, according to Schilling's initial idea, were linked by a laying of 8 conductors, of which 6 were connected to the galvanometers, one was used as a return or ground conductor and another as an alarm signal. Schilling made a further improvement and reduced the number of drivers to two.
On October 21, 1832, Schilling achieved a short-distance transmission of signals between two telegraphs in different rooms of his apartment. In 1836 the British government tried to buy the design, but Schilling accepted the proposal of Tsar Nicholas I of Russia. Schilling's telegraph was tested on a run of more than 5 km of experimental underground and submarine cable, arranged around the main Admiralty building in Saint Petersburg. The tests led to the approval of a telegraph line between the Imperial Palace of Peterhof and the Kronstadt naval base. However, the project was canceled after Schilling's death in 1837. Due to the theory of operation of his telegraph, Schilling is considered to have also been one of the first to put into practice the idea of a binary system for transmitting signals. signs.
Gauss and Weber's telegraph
The German mathematician, astronomer, and physicist Johann Carl Friedrich Gauss and his friend, Professor Wilhelm Eduard Weber, developed a new theory of terrestrial magnetism in 1831. Among the most important inventions of the time was the single-wire and two-wire magnetometer, which enabled both to measure even the smallest deviations of a compass needle. On May 6, 1833, both installed a 1,200-meter-long telegraph line on the roofs of the German town of Göttingen where they both worked, linking the university with the astronomical observatory. Gauss combined the Poggendorff-Schweigger multiplier with his magnetometer to build a galvanometer. To change the direction of the electric current, he built a switch of his own invention. As a result, he was able to make the needle on the receiving end move in the direction set by the switch at the other end of the line.
Gauss and Weber initially used the telegraph to coordinate time, but they soon developed other signals and eventually their own character encoding, now considered 5-bit. The alphabet was encoded in a binary code that was transmitted by positive or negative voltage pulses that were generated by means of an induction coil moving up and down on a permanent magnet and connecting the coil with transmission wires. through the switch. The page from Gauss's laboratory notebook containing his code and the first message transmitted, as well as a replica of the telegraph in the 1850s under Weber's instructions are kept at the Faculty of Physics at the University of Göttingen. Gauss was convinced that this communication would help the people of his country. Later in the same year, instead of a voltaic pile, Gauss used an induction pulse, allowing him to transmit seven characters per minute instead of two. The inventors and the university lacked funds to develop the telegraph on their own, so they received funding from the German scientist Alexander von Humboldt. The German engineer and astronomer Karl August von Steinheil in Munich was able to build a telegraph network within the city in 1835 and 1836 and although he created a telegraphic writing system, it was not adopted in practice. A telegraph line was first laid along the German railway in 1835.
Alter and the Elderton Telegraph
Across the Atlantic, in 1836, American scientist and inventor David Alter invented the first known American electrical telegraph, in Elderton, Pennsylvania, a year before Samuel Morse's telegraph. Alter demonstrated the device to witnesses, but never turned the idea into a practical system. He was later interviewed for the biographical and historical book Historical Cyclopedia of Indiana and Armstrong Counties. and Armstrong Counties), in which he said: "I can say that there is no connection between Morse's and others' telegraph, and mine.... Professor Morse has probably never heard of me." or of my Elderton telegraph."
Morse Telegraph
It is said that the idea of the telegraph occurred to the American painter Samuel Morse one day in 1836, who was coming back to his country from the European continent when he happened to overhear a conversation between passengers on the ship about electromagnetism. Samuel Morse began to think about the subject and became so obsessed with it that he lived and ate for months in his painting studio, as he noted in his personal diary.
From items from his studio such as an easel, a pencil, pieces of an old clock, and a pendulum, Morse made a then rather bulky device. The basic operation was simple: if there was no flow of electricity, the pencil would draw a straight line. When there was that flow, the pendulum swung and a zigzag was drawn on the line. Gradually, Morse made several improvements to the initial design until finally, together with his colleague, the American machinist and inventor Alfred Vail, created the code that bears his name. Thus, another code arose that can be considered binary, since from the initial idea a character formed by three elements was considered: point, line and space.
With the help of contact plates and a special pencil, which was run by electricity, signals could be transmitted over poor-quality wires. On January 6, 1838, Morse first successfully tested the device at the Speedwell Ironworks in Morristown, New Jersey, and on February 8 of that year, he made another public demonstration before a scientific committee at the Franklin Institute in Philadelphia., Pennsylvania. At this point, Samuel Morse, after unsuccessfully seeking funds to develop his invention, managed to get the United States Congress to approve in 1843 the allocation of $30,000 for the construction of a 60-kilometre experimental line between Baltimore and Washington, using their equipment. On May 1, 1844, the line had been completed at the United States Capitol in Annapolis Junction, Maryland. That day, the Whig Party of the United States nominated Henry Clay as its candidate for the Presidency. The news was carried by train to Annapolis Junction, where Alfred Vail was located, who transmitted it by telegraph to Morse who was in the Capitol. On May 24, 1844, after the line was completed, Morse made the first demonstration public of his telegraph sending a message from the Chamber of the Supreme Court in the United States Capitol in Washington D.C. to the B & O (now the B & O Railroad Museum) in Baltimore. The first sentence transmitted by this installation was «What hath God wrought?» («What has God brought us?», a quote that belongs to chapter 23 and the same verse of the Book of Old Testament numbers.
The Morse-Vail telegraph spread rapidly over the next two decades. Morse did not credit Vail for the powerful electromagnets used in his telegraph. Morse's original design, without the devices invented by Vail electromagnets, only worked at a distance of 40 feet (12 m). Until his death, Morse was concerned with the diffusion and improvements of his telegraph, abandoning his profession as a painter.
Despite the advantages of other systems that did not require knowing the code used by this team, this one (with different improvements) coexisted with those. The Morse alphabet has an almost exclusive application in the field of radio amateurs, and although its knowledge was required, until 2005, to obtain the license of amateur radio operator; today, licensing agencies in all countries are invited to waive the telegraphy exam for exam candidates. It is also used in instrument aviation to tune VOR, ILS and NDB stations. The navigation charts indicate the frequency along with a Morse signal that serves, via radio, to confirm that it has been correctly tuned.
Cooke and Wheatstone Telegraph
The first commercial electrical telegraph was co-developed by British inventors William Fothergill Cooke and Charles Wheatstone who filed a patent application in May 1837, which was granted on June 12, 1837. This device was successfully demonstrated 13 days later between Euston and Camden Town stations in London. This facility entered commercial service on the Great Western Railway over the 13-mile (20.9 km) run from Paddington Station to the of West Drayton on April 9, 1839. The following year, both inventors applied to patent their invention at the United States Patent Office, which granted them the patent in 1842.
Cooke and Wheatstone's system lacked punctuation marks, lowercase letters, and the letters C, J, Q, and Z; which originated writing errors or substitutions in which one word was substituted for another. Both the transmitter and the receiver were on a console with 10 pushbuttons or switches and a rhomboid dial with the alphabet engraved. To send any character, it was looked for in the quadrant and it was observed up to which galvanometers the lines that started from the character reached. Then the two corresponding switches on the top or bottom row were pressed, depending on where the letter was located. Taking the image that appears here as a reference, to convey the letter "A" all you had to do was hit the first and fifth switches on the top row. For the letter "W", it was only necessary to press the second and fifth switches on the bottom row. At the receiving end, the quadrant was read sequentially by the operator and the message was transcribed manually. It is clear that the omission of the mentioned characters is due to a question of the design of the dial, rather than to technical reasons of the system itself. Spoiled
Hughes Printing Telegraph
In 1856, British physicist and musician David Edward Hughes, then residing in the United States, created and patented the first printing system for telegraphy. In reality, Hughes only wanted to create a printer that would transcribe musical notes while playing one piece. In fact, the equipment he designed consists of both a 28-key piano-like keyboard, plus a "Shift" key; (Shift on English language keyboards) as typewriters, telex machines, and computers would later have. Each press on the keyboard was equivalent to sending a signal that caused a typographic wheel to print the corresponding character on the receiving end.
Unable to commercialize his invention in the United States, where the patent was held by Samuel Morse, in 1857, Hughes tried to introduce his invention in his country, England, but as he was unsuccessful he tried it in France, where his invention was a year on trial and finally, Napoleon III acquired it and awarded Hughes the medal of Chevalier (Knight). In other European countries, his invention was adopted and one of the companies that manufactured equipment based on Hughes's invention was Siemens Halske. This was in force with some technological improvements only in the European Continent until its adoption worldwide.
Hughes' telegraph surpassed the Morse telegraph in speed because it allowed transmission of up to 60 words per minute, compared to 25 for the Morse system. In addition, in his system he used a perforated code, but it allowed printing with normal characters, not requiring a subsequent translation. Although in this equipment it was not necessary to know any code to handle it, the synchronism system, which the operator had to maintain, made it very difficult to transmit without prior training. In fact, it was difficult to transmit, for example, two letters in a row that were not separated by at least six spaces in the alphabet. This equipment also worked with a pedal-operated clockwork system that involved the operator of the apparatus depressing a pedal on the right side of the apparatus frequently.
Baudot's Telegraph
The French Telegraph Engineer Émile Baudot, while working as an operator in the Post and Telegraph Administration, combined his knowledge of Hughes's telegraph with that of a multiplexing machine created in 1871 by Bernard Meyer and 5-bit coding de Gauss and Weber to develop his own telegraph system. The keyboard, instead of having the 28 keys of the Hughes system, had 5: 2 on the left side and 3 on the right. By pressing various combinations of these five keys, the operator encoded the character to be sent, according to the code table created by Émile Baudot. The inventor also developed another device capable of sending several messages at the same time, known as a Distributor to which several keyboards could be connected. This device was an electromechanical version of current time division multiple access.
At the receiving end, another similar distributor was connected to various printers, which printed the corresponding letters, numbers, and signs of the alphabet on strips of paper, which were then cut and pasted onto a sheet of paper.
On June 17, 1874, Baudot patented a first version of his equipment called the “Fast Telegraphy System” and a year later it was accepted by the French Post and Telegraph Administration, which established the first line with this equipment in November of 1877, between the cities of Paris and Bordeaux.
According to the 5-bit encoding initially developed by Baudot, 31 characters could be transmitted, in addition to the character representing the non-transmission state. It also uses two sets of characters, with their "space" both for letters and figures. It is much faster than Hughes's telegraph, since in addition to needing only 5 bits versus 1 per character, Baudot refined the magnetic circuits of electromagnets, reducing parasitic self-inductions as much as possible, allowing shorter pulses to be used. One of the disadvantages of this system is that the operator had to press the keys at the precise moment, at a rate of approximately twice per second. The distributor designed by Baudot maintained a turning speed of approximately 120 revolutions per minute and at each turn it gave a signal indicating that the keys could be pressed. This made it difficult for novice or less skilled operators to keep up with the transmission.
Ticker
The device that proved both successful and practical was the so-called teletypewriter created by Canadian inventor Frederick G. Creed. While working at the Iquique, Chile branch of the Central and South American Telegraph and Cable Company, Creed had the idea of creating equipment similar to a typewriter that would allow the operator to punch signals in Morse code on a piece of paper by pressing the appropriate character on the keyboard. Creed resigned from his employment and moved to the Scottish city of Glasgow, where he purchased a typewriter which he modified to create a hole-punch keyboard, which used compressed air to punch holes in a paper tape. He also created a reperforator (reception puncher) and a printer. The re-puncher punched the incoming Morse signals onto the paper tape and the printer decoded this tape to produce alphanumeric characters on plain paper. This was the origin of the high-speed Creed automatic printing system, which could run at an unprecedented 200 words per minute. So he started his own company called Creed & amp; Company in 1904. Its system was adopted by the English newspaper Daily Mail for the daily transmission of journalistic content. Later, it would also be adopted by other press agencies.
By the 1930s and 1940s, teletype machines were being produced by the Teletype Corporation in the United States, Creed & Company in Great Britain and Siemens in Germany.
With the invention of the teletype, telegraphic coding was fully automated. Early teletypes used the Baudot ITA-1 code, a five-bit code. This produced only thirty-two characters, defined in two position shifts (in English, called shift to allow changes from uppercase to lowercase), letters and figures. An explicit non-shared code preceded each set of letters and figures.
By 1935, message routing was the last major hurdle to full automation. Large companies that provided telegraphy equipment began to develop systems that used rotary dialing such as rotary telephones to connect teletypes. These machines were called "Telex" (abbreviation of the English expression TElegraph EXchange). In the telex machines, pulse dialing was carried out for circuit switching, and then they sent the data by the ITA2 code. This routing is "type A". At a speed of 45.45 ± 0.5% baud, considered very fast for the time, up to 25 telex channels could share the same long-distance telephone channel through the use of voice frequency division multiplexing, thus telex became the least expensive method of reliable long-distance communication. Other uses that were given to the telex machines were as a device for transmission by radio waves, thus emerging the radioteletype and as a peripheral input / output device for the first computers, through later mainframe computers, minicomputers and some computers. personal until its replacement by video terminals.
How the telegraph works
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When the switch, commonly called manipulator, is closed at the emitting station, a current flows from the electric battery to the line and the electromagnet, which causes a metallic piece ended in a wire to be attracted. punch that presses a strip of paper, which moves by means of drive rollers, moved by a clockwork mechanism, on a cylinder impregnated with ink, in such a way that, depending on the duration of the press of the switch, it will result in printing of a dot or a line on the strip of paper. The combination of dots and dashes on paper can be translated into alphanumeric characters by using an agreed code, in practice the most widely used for many years has been Morse code.
Subsequent improvements in the sending and transmitting devices have allowed the transmission of messages more quickly, without the need to resort to a manipulator and the manual translation of the code, as well as the simultaneous sending of more than one transmission over the same line. One of these advanced telegraphic devices is the teletype, whose initial model was a special typewriter that transmitted keystrokes on a keyboard as electrical signals while printing on a roll of paper or punching holes in a tape also made of paper. The most modern forms of this machine were made with a monitor or screen instead of a printer. The system is still used by people who are deaf or hard of hearing to send text messages over the telephone network.
The need to encode text into dots and dashes for transmission and decoding before writing the telegram led to the development of other types of telegraphy that performed these tasks automatically. Hughes's telegraph is based on two wheels that contain all the symbols or characters that can be transmitted and rotate, synchronized, at the same speed. So, if the transmitter wheel has, say, the C below, the receiver does too. This allows the receiver to print the corresponding character by transmitting a pulse at the right time. As the transmission speed depends on the number of symbols available, these are separated into two banks (letters and numbers), so that a letter and a number share the same code. There are two blanks or spaces, called "letter blank" and "number blank", which in addition to creating a space to separate words or numbers, indicate whether letters or numbers will be transmitted next. The transmitter has a keyboard, similar to a piano, with the characters. The radio operator presses the appropriate key and, when the wheel containing the characters is in the appropriate position, the device transmits a pulse to the line. In the receiver, an electromagnet strikes the paper tape against the wheel containing the type. These wheels are moved by a clockwork mechanism, with a weight or hydraulic motor, depending on the case. At the beginning of the day, a synchronization protocol was initiated, transmitting a message designed for this purpose. The transmission speed was lower than that of the Morse system, and depended on the radio operator, since an experienced one was capable of sending several characters in one turn of the wheel.
Telegraphy and multiple communications
In addition to the multiplexing of signals applied by Baudot, another way of sending various signals was also devised through the use of the so-called harmonic telegraphy, in which a telephone circuit transfers the signals that modulate various carrier signals of different frequencies in the vocal band.
Submarine telegraph lines
By 1850 the electric telegraph had spread throughout North America, England, and many parts of Europe. Although the overhead wires were very successful on land, they always stopped abruptly at the ocean's edge.
The Dover Strait cable had not been sufficiently protected. Only the ends on each beach had been armored in lead tubes. Although the cable worked to some degree, the signals coming from both sides of the canal were confusing. The fact that despite being properly insulated, the cable is greatly disturbed when submerged was not recognized. This problem of signal delay was to perplex many cable engineers for some time. However, in 1851, a truly armored cable was laid across the Channel which was much more successful than its predecessor. In a short space of time, a network of submarine cables was extended across the bed of the Mediterranean Sea, linking Europe with Africa and the intervening islands. Since successes like these were achieved, men began to think about crossing the bed of the Atlantic Ocean.
The first transatlantic telegraph cable
Although England began engineering submarine cables, American businessman Cyrus West Field persisted in efforts that ultimately resulted in the first successful cable being laid across the Atlantic Ocean, the result of a joint effort of the governments of England and the United States. On both sides, some of the world's most celebrated financiers, oceanographers, telegraphists, and scientists collaborated in this enterprise. The talents of these men would prove indispensable due to the deep submarine trenches that would be found in the middle of the Atlantic. Here the largest mountain range on Earth stretches 1,600 kilometers long and 800 kilometers wide, completely submerged.
Had Field and his associates known in advance of the many years of financial trouble and disaster that awaited them in laying the cable, they may well have backed off during their early efforts. Cable damage, adverse weather and cable entanglements in the boats' lowering apparatus constantly impeded the project. Sometimes hundreds of kilometers of broken cable, costing a fortune, were left at the bottom of the sea.
The old problem of signal delay needed to be solved. Someone had to figure out how long it would take for a signal to reach the far ends of the wire and how much electricity it would take to fill the wire before the signal could get through. Up to 20 times more electricity can be required to charge a submarine cable than an aerial one.
Sir William Thomson, better known as Lord Kelvin, deduced the Law of Squares as a result of his investigation of this matter. Simplified, this law expresses that if the length of a submerged cable is multiplied 10 times, the speed of the signal will be reduced 100 times. The solution he presented was to increase the size of the conducting center. However, because this new discovery was overlooked, the faulty design of the first Atlantic cable contributed to its subsequent failure.
But finally, on August 5, 1858, the first transatlantic submarine cable linked the continents between Ireland and Newfoundland. Eleven days later, a 99-word message of greetings from Queen Victoria of England to President James Buchanan of the United States began rolling over the lines. It was completed 16 1⁄2 hours later. Unfortunately, the cable failed less than a month later, representing, at current cost, close to two million dollars of private capital in losses. Eight years would pass before there could be telegraphic connections between Europe and America.
During the interim, the two cable manufacturers in England joined forces, thus solving many of the teething problems of cable construction. A new and better protected cable was designed. It was twice as heavy (6,350 tons) and had a center conductor three times as large as the previous cable. It could hang vertically in the water for 10 miles before breaking. And for the next effort, only one ship had to be used (instead of the two required before) because it was capable of carrying the great load. This vessel, the Great Eastern, had a double propulsion system with two 18-meter paddle wheels, six masts, and a seven-meter propeller. This made her the most maneuverable ship built to date. After two further unsuccessful efforts, a truly successful cable was completed on July 27, 1866. This united Ireland with Newfoundland. But at a distance of 1,100 kilometers from the new cable lay another entangled with the gear that had been lost. After 30 attempts, they managed to pull it to the surface, test it, and splice it with new cable. This completed the portion from west to east. With the union of the ends of the two cables in Newfoundland, an underwater circuit of more than 6,400 kilometers came into being. Clear signals were sent over this distance. All that was needed to charge this cable was a simple battery made from a silver thimble containing a few drops of acid. Since that time, two-way communication between the two continents has never ceased for more than a few hours at a time.
Dominance of the United Kingdom in the world telegraph network
In 1870 the laying of a line linking India with Great Britain was completed. And in 1874 the connection with Brazil was made through Lisbon and Madeira.
Other countries also became interested in a transatlantic telegraph cable. In 1869 France laid the line from Minou, near Brest, to Cape Cod in the United States. It was the first cable laid by a country other than the United Kingdom, although the company that had carried out the laying was taken over by UK companies in 1873. In 1879, France laid a second cable from Deolen, 17 km west of England. Brest, to Saint Pierre and Miquelon, and on November 17, 1879, arrived at Cape Cod.
In 1882, Germany connected Emden, by submarine cable, with the British station on Valentia Island and from there, used the Anglo American Telegraph service. However, in 1900, it made a own connection from Borkum to Horta in the Azores islands. And from there to New York. In 1904, he laid another cable along the same route.
This is how cable expansion continued. Fifteen cables had been laid in the North Atlantic by 1901. However, most of these cables had to pass through the United Kingdom, reinforcing its dominance.
In 1902, the laying of the telegraph cable across the Pacific Ocean was completed. Thus, at the beginning of the XX century, Great Britain already had a worldwide telegraph system that connected the main territories of its empire (all red lines in the attached figure).
Rival powers such as France and Germany had to use British-owned cables to relay their messages, and when war broke out in 1914, the Germans had to develop encryption systems to avoid being overheard by the Allied powers.
Social importance of telegraphy
Some contemporaries of its invention saw a democratizing potential in the telegraph. By communicating people over great distances, it seemed that this technology could spread democracy on a large scale. A year after the inauguration in 1794 of the first Paris-Lille optical telegraphy line, Alexandre Vandermonde (1735-1796) wrote:
Something has been said about the telegraph that seems infinitely just to me and reveals all its importance; it is that the substance of this invention can suffice to make possible the establishment of democracy in a great people. Many respectable men, including Jean-Jacques Rousseau, have thought that the establishment of democracy was impossible in the great peoples. How can a people like this deliberate? Among the ancients, all citizens gathered in a square; their will was communicated [·····] The invention of the telegraph is a new fact that Rousseau could not include in his calculations. It can serve to speak at great distances as simply and as clearly as in a room [····] There is no impossibility for all citizens of France to communicate their information and wills, in a rather short time, so that this communication can be considered instantaneousAlexandre Vandermonde (1795)
The sociologist Armand Mattelart has pointed out how this supposed democratizing potential was denied by the embargo on the encrypted code and by the refusal of the State, in the name of internal security and national defense, to allow the telegraph to be used freely and openly by the citizens.
End of the era of telegraphy
After the invention in 1985 of the short message service by the Finnish engineer Matti Makkonen (1952–2015) that was implemented in cell phone networks and the creation of the email service through the Internet, he lost The transmission of telegraphic messages became important since the users of the telecommunications networks began to transmit their own messages without intermediaries. In the United States, the Western Union company closed its telegraphic services on January 27, 2006. For its part, the Indian state-owned company Bharat Sanchar Nigam Limited closed its telegraphic services on July 14, 2013. It was reported at the time to be the last active telegraphy network in the world.
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