Invention of the telephone
The invention of the telephone goes back to several people. Who can be considered the true inventor here is controversial.
Development history of the telephone up to its basic form from 1878
In the 1810s and 1820s, many researchers experimented with the interactions of magnetism and electric current. In 1820 Hans Christian Ørsted showed that a current-carrying coil creates a magnetic field ( electromagnetism ) . In 1831 Michael Faraday published his findings on electromagnetic induction , which states, among other things, that a changing magnetic field in a metallic object, especially a coil , generates an electrical voltage in it. This also provided a basic possibility of converting mechanical vibrations into changing electrical currents and vice versa. The American Charles Grafton Page discovered the electric tuning fork in 1837, which uses electromagnetism to generate a tone when a direct current is periodically switched on and off, the pitch of which depends on the switching frequency.
In addition to electromagnetic induction, there was a second, obvious way of translating mechanical vibrations into changes in current, namely the direct use of mechanical movement to open and close a contact within an electrical circuit. In contrast to electromagnetic induction, a battery was required to generate an electrical current . Generalize settled this principle of sound-controlled switch to the principle of sound-controlled resistance , in which a mechanical action pulls the change in electrical resistance of a material arrangement to be. However, there were early doubts about the appropriateness of a pure switch for translating language into current changes.
Both approaches, electromagnetic induction and the principle of the sound-controlled switch or resistor, were investigated and used in the following to convert tones into fluctuations in current. For the opposite direction, i.e. the conversion of changing current into tones, the principle of electromagnetism was used almost exclusively, i.e. the movement of a current-carrying coil in a magnetic field. The actual sound transducers were supplemented by aids for bundling and amplifying sound, such as funnels, membranes and resonance bodies.
The conversion of sounds into electricity and back for the purpose of speech transmission has been studied and discussed many times. In 1843, for example, Innocenzo Manzetti postulated a "speaking telegraph". In 1854, the Parisian telegraph officer Charles Bourseul developed concepts for voice transmission, whereby the conversion should take place with a thin plate that could close and open the circuit.
The first devices were presented to the public around 1860. It is alleged that the Italian-American stage technician and inventor Antonio Meucci presented his telephone set in 1860. What is certain is that in 1861 the German teacher and inventor Philipp Reis presented his device, which he called the “telephone”, to the members of the Physikalischer Verein in Frankfurt .
While the developments of Reis from 1861 onwards are well documented, Meucci's contributions can only be clearly demonstrated from 1871 onwards. There are reports of newspaper articles from before 1871, but none of them have survived. The circuit diagrams that exist today for the alleged earlier developments were all made later. In the telephones shown there, the sound is converted by electromagnetic induction. In a patent application by Meucci from 1871, however, only a sketch of people talking over wire can be seen; the description of how it works is extremely unclear and raises doubts as to whether Meucci even used electricity to transmit signals. This inadequate description was one of the reasons why Meucci was later unable to assert any claims to the invention of the telephone in court.
In Reis' telephone, the conversion of tones to changes in current took place using the principle of sound-controlled resistance or switches. Reis only planned to use a sound-controlled switch, with which two metal contacts, one of which was connected to a membrane, could close and open a circuit. In later investigations it turned out that it was not just a sound-controlled switch, but to some extent a sound-controlled resistor due to the nature of the metal brackets. The voice quality was assessed differently and was probably not constant. Reis improved his device and from 1863 sold it worldwide as a demonstration object.
These early devices showed the feasibility of converting sounds into electrical signals and back, but they were still a long way from being used in practice. Development continued, and Meucci and Reis also made improvements to their apparatus. Meucci wanted to apply for a patent for his device in 1871, but for financial reasons he could only afford a preliminary patent from 1871 to 1874. Reis died in 1874.
In 1876, other phones were first described and built by others. On the same day, February 14, 1876, two similar patent applications were filed with the US Patent Office, on the one hand by the deaf-mute teacher Alexander Graham Bell and on the other hand by the inventor Elisha Gray . Both of the applicants were well aware of Reis' work; Meucci's work was probably at least known to Bell.
Although Bell did not have a working prototype and Gray's application contained more technical details, the patent was awarded to Bell because he had filed his application shortly before Gray. There were repeated doubts about the legality of the patent procedure. The conversion process described by Gray was based on the principle of sound-dependent resistance, which was realized by the variable immersion of a needle in an acid-filled vessel. After Bell received the patent, he built a prototype using Gray's conversion process, which he had never described himself. Objections followed, including from Meucci, and endless legal battles between Gray and Bell, but Bell's patent claim was repeatedly confirmed.
Since the liquid process was not practical, Bell and his colleagues quickly turned to the conversion principle of electromagnetic induction, with which they had previously experimented according to their own statements. In June 1876 they were able to present a working model based on electromagnetic induction at the world exhibition in Philadelphia . In 1877 Bell founded the forerunner of the Bell Telephone Company together with his lawyer and later father-in-law Gardiner Greene Hubbard .
Independently of the new devices from Gray and Bell, the Englishman David Edward Hughes had already developed the carbon microphone with graphite rods based on the principle of sound-controlled resistance in the early 1870s. This transducer principle became generally known in 1877, and other inventors such as the German-American Emil Berliner and the American Thomas Alva Edison further developed the carbon microphone and partially claimed the invention for themselves. Compared to induction-based power generation, carbon-microphone telephones had the advantage of being able to deliver much higher currents, which was crucial in a time without amplifier technology. Edison was granted a patent for the carbon granulate microphone in 1878 , which was soon used in all telephones. With the carbon granulate microphone as a sound-current converter and the electromagnetic loudspeaker as a current-sound converter, the basic form of the telephone was found, which was retained for many years.
Relation to telegraphy and radio
The telephone would not have been possible without the electrical transmission of characters. Already 1833 in Goettingen by Carl Friedrich Gauss and Wilhelm Eduard Weber implemented the transmission of coded signals via electrical lines in practice. This procedure, which was initially very cumbersome and time-consuming, has been further developed by others over the course of time. Telegraphy and the Morse machine developed in 1837 by Samuel FB Morse and his colleague Alfred Vail , which was based on an idea by the physicist Joseph Henry , are considered to be forerunners . Improvements followed, including the teletype system.
Back in 1900, the wireless began radio transmission , which, however, only with the wireless devices and the digital technology in the 1990s for anyone with the mobile telephony was affordable.
People and stations
1837 - Charles Grafton Page
In 1837, the American Charles Grafton Page (1812–1868) placed a wire spiral through which an electric current flows between the poles of a horseshoe magnet . He observed that sound vibrations occurred as the current appeared and disappeared. He called this phenomenon "galvanic music".
1844 - Innocenzo Manzetti
In 1844 Innocenzo Manzetti (1826–1877) postulated the possibility of a telegraph. At the beginning of the 1860s he came back to this work and created an electrical apparatus from 1864-1865 that was able to transmit the human voice over half a kilometer. The apparatus, considerably improved, was presented to the press in the summer of 1865. Newspapers all over the world announced that it was now possible to use an electrical device to transmit human words over long distances.
Antonio Meucci , who was still unknown at the time and who emigrated to America, had achieved something comparable. After Meucci read about Manzetti's invention, he wrote to an American newspaper "I cannot deny Mr. Manzetti's invention" and immediately described his prototype of a telephone set - much more primitive than Manzetti's: With Meucci's device you were forced to put a clamp between to stick one's teeth while one could speak freely with a handset using the Manzetti telephone. Manzetti couldn't patent his invention because he didn't have enough money. Meucci, on the other hand, had his invention patented, but only got a provisional patent that he had to constantly renew. When he was unable to raise the amount required for the renewal in 1871, the patent expired in 1873.
1854 - Charles Bourseul
The first ideas about a telephone came around 1854, when the military wanted faster means of communication . The Parisian telegraph officer Charles Bourseul (1829-1912) then wrote a lecture on possible techniques of electrical voice transmission. He proposed a movable plate that alternately opens and closes a circuit. However, neither scholars nor the public of the time recognized the importance of Bourseul's idea; he was referred to as a dreamer and "harmless madman". Bourseul then gave up his plans for the implementation of the idea.
1860 - Antonio Meucci
In New York , the Italian theater mechanic Antonio Meucci (1808–1889) developed a telephone connection for his wife who could not leave her room due to a rheumatic disease. Meucci publicly presented his device in 1860 and described it in an Italian-language newspaper in New York.
Financial losses through speculation ended his independence. Due to burns from a kettle bang , Meucci was given three months' sick leave in 1866, which resulted in his discharge and forcing his wife to sell some of his work models, including that of a telephone. Nevertheless, Meucci later continued the work and filed a patent application for it in 1871. For the final registration, however, he could not afford the costs, the validity of the reservation expired in 1873. Even contacting the Western Union Telegraph Company was unsuccessful for Meucci.
Alexander Graham Bell came into possession of Meucci's materials and documents in the course of these events. When Meucci asked for his equipment and documents back in 1874, he was told that they had been lost. After Bell applied for a patent for "his" phone in 1876, Meucci tried to challenge it. Despite decades of disputes and attempts to get at least financial compensation from Bell, he did not succeed. He died impoverished.
As early as 1887, the US authorities attempted to withdraw the invention of the telephone from Alexander Graham Bell in fraud proceedings. However, with Meucci's death in 1889, the public lost interest in the case.
On June 11, 2002, the House of Representatives of the United States Congress of America passed a resolution honoring Antonio Meucci's invention and his work in introducing the telephone.
1861 - Johann Philipp Reis
Johann Philipp Reis (1834–1874) succeeded for the first time in establishing a functioning electrical telephone connection. In the course of his invention, he had also developed the contact microphone and introduced the word "telephone". The baker's son, who comes from Gelnhausen in Hesse , had received a higher education in Frankfurt am Main and Friedrichsdorf and was hired as a teacher of physics and mathematics at the Institute of Hofrat Garnier in Friedrichsdorf.
Between 1858 and 1863 he developed three different, improved prototypes of his telephone. The basis for his contact microphone was the wooden model of an auricle that he had developed for physics class. A piece of natural gut with a fine strip of platinum as a simulated ossicle served as a modeled ear drum . If sound waves hit this "eardrum", they caused it to vibrate, which interrupted the circuit between the metal strip and the wire spring. In the course of his experiments, Reis realized that instead of the ear model, a horn covered with a membrane could also be used. A knitting needle with a copper wire coil attached to it served as a receiver with a loudspeaker function . The current pulses sent by the transmitter - the contact microphone - now flowed through this coil. The movements of the iron needle caused by the electromagnetic impulses in turn generated sound waves. To amplify the notes, Reis used a wooden box as a soundboard.
On October 26, 1861, he presented the telephone to numerous members of the Physikalischer Verein in Frankfurt for the first time publicly with the announcement “The horse does not eat cucumber salad”. After that, Reis improved the device significantly until 1863 and sold it in large quantities worldwide as a scientific demonstration object. This is how specimens came to the USA. The German invention was used there from 1868 onwards. Alexander Graham Bell had already met an early model of the Reis telephone in Edinburgh in 1862 . In 1875 he experimented with Reis' telephone set and benefited from basic German research that was important to him. So Bell and his assistant Thomas A. Watson set about building a device that - similar to Reis' telephone - converted the vibrations of a membrane into electrical vibrations.
In 1865 the British-American inventor David Edward Hughes was able to achieve good results in England with the German "telephone".
A test carried out by the telephone company STC in 1947 with this telephone confirmed the tests carried out by international experts while Reis was still alive. It was found once again that the Reis'sche telephone transmitted speech of very good quality, but only with poor efficiency. This fact was deliberately kept secret by Frank Gill, the chairman of STC, for years, because he had a business relationship with AT&T and did not want to burden the business climate.
Especially German scientists like the well-known academic Johann Christian Poggendorff were not convinced by Reis' idea, although there was also positive support from the communications industry, especially from the influential Wilhelm von Legat. To many experts, the already more sophisticated telegraphy seemed far superior.
1875 - Elisha Gray
The versatile American craftsman Elisha Gray also studied electricity and telegraphy . He first filed a patent for a telegraphic device in 1876 - two hours after Bell ; he was followed by 50 more on telegraph technology. 1869 founded Gray in Cleveland , Ohio an electricity company that later in Chicago with the Western Electric Manufacturing Company for Western Electric Company was incorporated. In 1876 Gray left the company to devote himself to the exploitation of his inventions, which were mainly relays and printing telegraphs.
In 1875 Gray began experiments with the electrical transmission of sounds, the result of which he laid down in a patent application. However, Alexander Graham Bell was two hours ahead of this patent application , and Bell's application was preferred to Gray's. Gray then allied with the Western Union Telegraph Company , the largest telegraph company at the time, which had previously not been interested in buying Bell's patent . The "Western Union" also began to build a telephone network. Soon thereafter, the first patent litigation began, in which Bell's part in the invention of the telephone was up for debate. Gray and the Western Electric Company allied with him did not succeed in asserting their claims against Bell.
1876 - Alexander Graham Bell and Thomas A. Watson
The deaf-mute teacher Alexander Graham Bell , who was born in Edinburgh, Scotland and later emigrated to Canada and who opened a private school for voice physiology in 1873, carried out experiments with a " harmonic telegraph " for multiple telegraphy or the simultaneous transmission of several pieces of information. He realized that the reproduction of speech requires changes in the current flow instead of repeated interruptions. Bell had already found a solution for the implementation in the findings of electromagnetic induction, which go back to the physicist Michael Faraday (1791–1867). However, there was a lack of the specialist knowledge necessary to carry it out.
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Bell's telephone was essentially based on two previous developments, on the one hand that of Antonio Meucci, whose materials and documents Bell was able to use, and on the other, an early model of a telephone by Philipp Reis , which Bell had met in Edinburgh in 1862 . From 1868 the German invention was used in the USA. In March 1875, Bell experimented with Reis' telephone set at the American research and educational establishment, the Smithsonian Institution, and benefited from basic research on German, which was important to him. So Bell and his assistant Thomas A. Watson set about building a device that - similar to Reis' telephone - converted the vibrations of a membrane into electrical vibrations.
After several attempts, on February 14, 1876, Bell had the celebrity attorney Gardiner Greene Hubbard, whose daughter he was planning to marry, go to the office with a vaguely worded patent application for a telephone. Just two hours later, the teacher, inventor and entrepreneur Elisha Gray also tried to register a phone. In contrast to Bell, who had not yet achieved a goal with his experiments, Gray described his phone in detailed script. As a result, it turned out that Bell's patent application could not work at all. But he was in a hurry, having learned that other inventors were working on telephones.
Three weeks later, on March 7th, Bell received the patent for his phone. He benefited from the fact that a few years earlier the patent office had decided not to submit a working model for the patent application. This patent, which was awarded to him, was invaluable in allowing Bell to ban all other competitors from activities in the telephone field. Even the powerful Western Union Telegraph Company, which Elisha Gray had under contract and had developed a device other than Bell's in response to Thomas Alva Edison's patent , failed after countless lawsuits. Bell was able to win all of the almost 600 subsequent lawsuits, as the courts mostly cited the fact that Bell was the first to receive the patent.
The patent dispute began when Bell used, among other things, an adjustable resistor in the later practical implementation of his telephone, which was not listed in his patent specification, but was detailed in Elisha Gray's application. Now the voices grew louder that saw an illegal connection between Bell and the patent office. An official accused himself of bribery, but his apparently fickle testimony was also questioned in the international trade press.
Bell also looted Gray's patent specification for other essential details. The first prototype presented by Bell three weeks after filing the application and three days after the patent was granted consisted of, among other things, a membrane and a microphone, as specified in Gray's patent application. Bell's expert assistant Thomas Watson (not to be confused with the first president of the same name of IBM (1874-1956)) subsequently made further improvements. From 1877 a new type of sound transducer was installed that used the pressure-dependent contact resistance between the membrane and a piece of carbon to generate signals. Both the British-American designer and inventor David Edward Hughes , who experimented with an imported German telephone in 1865, and the German-American inventor Emil Berliner in 1877 during his , are considered to be the inventors of this carbon microphone, which is based on the contact microphone invented by Philipp Reis Worked for the Bell Telephone Company . Nevertheless, it was not until 1881 that the Bell telephone was practically operational.
Like Charles Bourseul, Bell also had difficulty getting the public interested in the invention. The fame necessary for the success of his invention was finally achieved by scientists in the wake of the then Emperor of Brazil, Pedro II , to whom the telephone was presented at an exhibition in June 1876. The scientists saw in the apparatus "the greatest miracle that has ever been performed in the field of electricity " and thus contributed decisively to its dissemination. Bell himself was well aware of the value of his invention, and so in 1877 he founded the Bell Telephone Company, which was to take over the construction of a telephone network in the United States. The Bell Telephone Company was renamed the American Telephone and Telegraph Company (AT&T) in 1885 and has become the world's largest telephone company to this day.
The New York Times first mentioned the phone on May 12, 1877 under the title “Prof. Bell's Telephone ”. The night before, Bell had set up a phone call between the audience and a Mr. Gower at 340 Fulton St. in Brooklyn in front of 200 invited guests at the St. Denis Hotel in New York City. The Times of London first reported on the telephone on January 21, 1878, at a meeting of the Physical Society on January 19. There WH Preece from the Postal Telegraph Department gave a lecture on "Some Physical Points connected with the Telephone". Among other things, the invention brings advances in electricity research. Bell is not mentioned, but Edison is.
1879 - Wilhelm Emil Fein
In 1879 Wilhelm Emil Fein received a patent for a telephone with a horseshoe magnet and in 1885 another for a military field telephone - this is considered the first portable telephone in the world (with cable connections).
1889 - Almon Brown Strowger
Almon Brown Strowger developed the electromechanical rotary dial in 1889 , which is the technical basis for the world's first automatically operating telephone exchanges.
1894 - Mihajlo Pupin
In 1894, Mihajlo Pupin invented the Pupin coil named after him , which made it possible for the first time to transmit tones without distortion over greater distances.
1900 - Reginald Fessenden
On December 23, 1900, Reginald Fessenden carried out a first experiment in wireless voice transmission with a machine transmitter .
1902 - Valdemar Poulsen
In 1903 Valdemar Poulsen invented the arc transmitter to generate undamped vibrations. In 1904 he was able to establish a voice connection using radio technology for the first time . In 1906 the mature technology was published. The pop-spark transmitter and the extinguishing spark transmitter for Morse transmission had already been invented beforehand .
1913 - Alexander Meissner
It was not until 1913 that Alexander Meißner succeeded in achieving the first flawless feedback reception with a circuit with love tubes (based on Robert von Lieben ) .
See also
Web links
- Spiegel Online / Frank Patalong: The rude methods of the famous Mr. Bell
- Bell listener from 1877 of the Museum Foundation Post and Telecommunications
- History of telecommunications from 1809 to 1999 with many pictures
Individual evidence
- ^ German Telephone Museum: Telephone by Antonio Santi Giuseppe Meucci. Retrieved September 15, 2019 .
- ^ A. Edward Evenson: The Reis Telephone Transmitter 1862-1872. Retrieved September 15, 2019 .
- ^ Stiftung Deutsches Historisches Museum / LeMO: October 1861: The invention of the telephone. Retrieved September 23, 2019 .
- ↑ Frank Patalong: Invention of the Telephone: The Rude Methods of the Famous Mr. Bell . In: Spiegel Online . October 3, 2012 ( spiegel.de [accessed September 23, 2019]).
- ↑ Telephone . In: Meyers Konversations-Lexikon . 4th edition. Volume 6, Verlag des Bibliographisches Institut, Leipzig / Vienna 1885–1892, p. 153.
- ↑ Charles Grafton Page ( Memento of the original from February 8, 2007 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- ^ Thomas Görne: Sound engineering. Hanser Verlag, 2008, ISBN 978-3-446-41591-1 , p. 201.
- ^ Resolution of the American Congress of June 11, 2002
- ↑ Werner Rammert: Technology from a sociological perspective. Westdeutscher Verlag, Opladen, 1993, ISBN 3-531-12421-8 , p. 249.
- ^ A b c d Silvanus P. Thompson: Philipp Reis: Inventor of the telephone. E. & FN Spon, London 1883.
- ^ A b Horst Kant: "A mighty stimulating circle" - the beginnings of the Physical Society in Berlin. Preprint 2002, Max Planck Institute for the History of Science, Berlin 2002.
- ↑ Ferdinand Rosenberger: The history of physics. Georg Olms Verlag, Frankfurt am Main 1882, p. 792.
- ↑ ABC of German inventions . Report by Dorothee Ott and Kristine von Soden. Hessischer Rundfunk , December 23, 2010.
- ^ Hermann Julius Meyer: Meyers Konversationslexikon , Bibliographisches Institut, Leipzig, 1894, p. 314.
- ↑ Werner Rammert: Technology from a sociological perspective. Westdeutscher Verlag, Opladen, 1993, ISBN 3-531-12421-8 , p. 234.
- ↑ a b c d e Joachim Beckh: Blitz und Anker, Volume 1: Information technology - history and backgrounds. Books on Demand, 2005, ISBN 3-8334-2996-8 , p. 223.
- ↑ a b Rudolf Vierhaus (Ed.): German biographical encyclopedia. 2nd revised edition. KG Saur-Verlag, Munich / Leipzig 2007, ISBN 978-3-598-25030-9 , p. 303.
- ↑ a b E.CS: Calendar of Scientific Pioneers. In: Nature. 106, January 13, 1921, pp. 650f.
- ^ Jörg Becker: Fern-Sprechen: Internationale Fernmeldegeschichte, -sociology and politics. Verlag Vistas, 1994, ISBN 3-89158-094-0 , p. 52.
- ↑ Bernd Fleßner: Ingenious thinkers and clever inventors 20 groundbreaking inventions of mankind. Beltz & Gelberg Verlag, 2007, ISBN 978-3-407-75329-8 , p. 74.
- ↑ Patent US174465 : Improvement in Telegraphy. Registered February 14, 1876 , published March 7, 1876 , inventor: Alexander Graham Bell.
- ^ Electrotechnical Association (Ed.): Electrotechnical magazine. 9th year, Verlag Julius Springer, 1888, p. 231.
