Émile Baudot
Encyclopedia
Jean-Maurice-Émile Baudot (September 11, 1845 – March 28, 1903), French
telegraph
engineer
and inventor of the first means of digital communication Baudot code
, was one of the pioneers of telecommunication
s. He invented a multiplexed printing telegraph system that used his code and allowed multiple transmissions over a single line.
, France
, the son of farmer Pierre Emile Baudot, who later became the mayor of Magneux. His only formal education was at his local primary school, after which he carried out agricultural work on his father's farm before joining the French Post & Telegraph Administration as an apprentice operator in 1869.
The telegraph service trained him in the Morse telegraph
and also sent him on a four-month course of instruction on the Hughes printing telegraph system, which was later to inspire his own system.
After serving briefly during the Franco-Prussian War
, he returned to civilian duties in Paris during 1872.
in telegraphy. Using synchronized clockwork-powered switches at the transmitting and receiving ends, he was able to transmit five messages simultaneously; the system was officially adopted by the French Post & Telegraph Administration five years later.
Baudot invented his telegraph code
during 1870 and patented it during 1874. It was a 5-bit code, with equal on and off intervals, which allowed telegraph transmission of the Roman alphabet, punctuation and control signals. By 1874 or 1875 (various sources give both dates) he had also perfected the electromechanical hardware to transmit his code. His inventions were based on the printing mechanism from Hughes' instrument, a distributor invented by Bernard Meyer
during 1871, and the five-unit code devised by Carl Friedrich Gauss
and Wilhelm Weber
. Baudot combined these, together with original ideas of his own, to produce a complete multiplex system.
The main element of Baudot's system was the distributor in which a rotating contact made brief contact with a series of sectors. Five contacts were used to send a group of signals making up a single character for transmission. The distributor was driven by falling weights or an electric motor. Correcting signals were transmitted to keep both ends in synchronisation.
Each operator - there were as many as four - was allocated a single sector. The keyboard had just five piano type keys, operated with two fingers of the left hand and three fingers of the right hand. The five unit code was designed to be easy to remember. Once the keys had been pressed they were locked down until the contacts again passed over the sector connected to that particular keyboard, when the keyboard was unlocked ready for the next character to be entered, with an audible click (known as the "cadence signal") to warn the operator. Operators had to maintain a steady rhythm, and the usual speed of operation was 30 words per minute.
The receiver was also connected to the distributor. The signals from the telegraph line were temporarily stored on a set of five electromagnet
s, before being decoded to print the corresponding character on paper tape.
Accurate operation of this system depended on the distributor at the transmitting end keeping in synchronization with the one at the receiving end and operators only sending characters when the contacts passed over their allocated sector. This could be achieved at a speed of 30 wpm by strictly observing the "cadence" of rhythm of the system when the distributor gave the operator the use of the line.
The Baudot apparatus was shown at the Paris Exposition Universelle (1878)
and won him the Exposition's gold medal, as well as bringing his system to worldwide notice.
During July, 1887, he conducted successful tests on the Atlantic telegraph cable between Weston-super-Mare
and Waterville, Nova Scotia
operated by the Commercial Company, with a double Baudot installed in duplex, the Baudot transmitters and receivers substituted for the recorder.
On August 8, 1890 he established communications between Paris, Vannes
, and Lorient
over a single wire. On January 3, 1894 he installed a triplex apparatus on the telegraph between Paris and Bordeaux that had previously been operating with some difficulty on the Hughes telegraph system. On April 27, 1894, he established communications between the Paris stock exchange and the Milan stock exchange, again over a single wire, using his new invention, the retransmitter. The British Post Office adopted the Baudot system during 1897 for a simplex circuit between London and Paris.
During 1897 the Baudot system was improved by switching to punched tape
, which was prepared offline like the Morse tape used with the Wheatstone
and Creed systems. A tape reader, controlled by the Baudot distributor, then replaced the manual keyboard. The tape had five rows of holes for the code, with a sixth row of smaller holes for transporting the tape through the reader mechanism. Baudot’s code was later standardised as International Telegraph Alphabet Number One.
Baudot received little help from the French Telegraph Administration for his system, and often had to fund his own research, even having to sell the gold medal awarded by the 1878 Exposition Universelle during 1880.
The Baudot telegraph system was employed progressively in France, and then was adopted in other countries, Italy being the first to introduce it, in its inland service, during 1887. Holland followed in 1895, Switzerland in 1896, and Austria and Brazil in 1897. The British Post Office adopted it for a simplex circuit between London and Paris during 1897, then used it for more general purposes from 1898. During 1900 it was adopted by Germany, by Russia in 1904, the British West Indies in 1905, Spain in 1906, Belgium in 1909, Argentina in 1912, and Romania in 1913.
Soon after starting work with the telegraph service, Baudot began to suffer physical discomfort and was frequently absent from work for this reason, for as long as a month on one occasion. His condition affected him for the rest of his life, until he died on March 28, 1903, at Sceaux, Hauts-de-Seine
, near Paris, at the age of 57.
telegraph and obtained a new patent which was also rejected. In the meantime, Baudot had patented his prototype telegraph a few weeks earlier.
Mimault claimed priority of invention over Baudot and brought a patent suit against him during 1877. The Tribunal Civil de la Seine, which reviewed testimony from three experts unconnected with the Telegraph Administration, found in favor of Mimault and accorded him priority of invention of the Baudot code and ruled that Baudot's patents were simply improvements of Mimault's. Neither inventor was satisfied with this judgment, which was eventually rescinded with Mimault being ordered to pay all legal costs.
Mimault became unnerved because of the decision, and after an incident where he shot at and wounded two students of the École Polytechnique
(charges for which were dropped), he demanded a special act to prolong the duration of his patents, 100,000 Francs, and election to the Légion d'honneur. A commission directed by Jules Raynaud (head of telegraph research) rejected his demands. Upon hearing the decision, Mimault shot and killed Raynaud, and was sentenced to 10 years forced labour and 20 years of exile.
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
telegraph
Telegraphy
Telegraphy is the long-distance transmission of messages via some form of signalling technology. Telegraphy requires messages to be converted to a code which is known to both sender and receiver...
engineer
Engineering
Engineering is the discipline, art, skill and profession of acquiring and applying scientific, mathematical, economic, social, and practical knowledge, in order to design and build structures, machines, devices, systems, materials and processes that safely realize improvements to the lives of...
and inventor of the first means of digital communication Baudot code
Baudot code
The Baudot code, invented by Émile Baudot, is a character set predating EBCDIC and ASCII. It was the predecessor to the International Telegraph Alphabet No 2 , the teleprinter code in use until the advent of ASCII. Each character in the alphabet is represented by a series of bits, sent over a...
, was one of the pioneers of telecommunication
Telecommunication
Telecommunication is the transmission of information over significant distances to communicate. In earlier times, telecommunications involved the use of visual signals, such as beacons, smoke signals, semaphore telegraphs, signal flags, and optical heliographs, or audio messages via coded...
s. He invented a multiplexed printing telegraph system that used his code and allowed multiple transmissions over a single line.
Early life
Baudot was born in Magneux, Haute-MarneMagneux, Haute-Marne
Magneux is a commune in the Haute-Marne department in north-eastern France....
, France
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
, the son of farmer Pierre Emile Baudot, who later became the mayor of Magneux. His only formal education was at his local primary school, after which he carried out agricultural work on his father's farm before joining the French Post & Telegraph Administration as an apprentice operator in 1869.
The telegraph service trained him in the Morse telegraph
Morse code
Morse code is a method of transmitting textual information as a series of on-off tones, lights, or clicks that can be directly understood by a skilled listener or observer without special equipment...
and also sent him on a four-month course of instruction on the Hughes printing telegraph system, which was later to inspire his own system.
After serving briefly during the Franco-Prussian War
Franco-Prussian War
The Franco-Prussian War or Franco-German War, often referred to in France as the 1870 War was a conflict between the Second French Empire and the Kingdom of Prussia. Prussia was aided by the North German Confederation, of which it was a member, and the South German states of Baden, Württemberg and...
, he returned to civilian duties in Paris during 1872.
Telegraphy
The Telegraph Service encouraged Baudot to develop during his own time a multiple Hughes system for time-multiplexing several telegraph messages. He realised that with most printing telegraphs of the period the line is idle for most of the time, apart from the brief intervals when a character is transmitted. Baudot devised one of the first applications of time-division multiplexingTime-division multiplexing
Time-division multiplexing is a type of digital multiplexing in which two or more bit streams or signals are transferred apparently simultaneously as sub-channels in one communication channel, but are physically taking turns on the channel. The time domain is divided into several recurrent...
in telegraphy. Using synchronized clockwork-powered switches at the transmitting and receiving ends, he was able to transmit five messages simultaneously; the system was officially adopted by the French Post & Telegraph Administration five years later.
Baudot invented his telegraph code
Baudot code
The Baudot code, invented by Émile Baudot, is a character set predating EBCDIC and ASCII. It was the predecessor to the International Telegraph Alphabet No 2 , the teleprinter code in use until the advent of ASCII. Each character in the alphabet is represented by a series of bits, sent over a...
during 1870 and patented it during 1874. It was a 5-bit code, with equal on and off intervals, which allowed telegraph transmission of the Roman alphabet, punctuation and control signals. By 1874 or 1875 (various sources give both dates) he had also perfected the electromechanical hardware to transmit his code. His inventions were based on the printing mechanism from Hughes' instrument, a distributor invented by Bernard Meyer
Bernard Meyer
Bernard Meyer was a French show jumping champion.-Olympic Record:Meyer participated at the 1912 Summer Olympics held in Stockholm, where he obtained a silver medal in Team Jumping with the French team.-References:...
during 1871, and the five-unit code devised by Carl Friedrich Gauss
Carl Friedrich Gauss
Johann Carl Friedrich Gauss was a German mathematician and scientist who contributed significantly to many fields, including number theory, statistics, analysis, differential geometry, geodesy, geophysics, electrostatics, astronomy and optics.Sometimes referred to as the Princeps mathematicorum...
and Wilhelm Weber
Wilhelm Eduard Weber
Wilhelm Eduard Weber was a German physicist and, together with Carl Friedrich Gauss, inventor of the first electromagnetic telegraph.-Early years:...
. Baudot combined these, together with original ideas of his own, to produce a complete multiplex system.
Baudot system
On June 17, 1874, Baudot patented his first printing telegraph (Patent no. 103,898 "Système de télégraphie rapide"), in which the signals were translated automatically into typographic characters. Baudot's hardware had three main parts: the keyboard, the distributor, and a paper tape.The main element of Baudot's system was the distributor in which a rotating contact made brief contact with a series of sectors. Five contacts were used to send a group of signals making up a single character for transmission. The distributor was driven by falling weights or an electric motor. Correcting signals were transmitted to keep both ends in synchronisation.
Each operator - there were as many as four - was allocated a single sector. The keyboard had just five piano type keys, operated with two fingers of the left hand and three fingers of the right hand. The five unit code was designed to be easy to remember. Once the keys had been pressed they were locked down until the contacts again passed over the sector connected to that particular keyboard, when the keyboard was unlocked ready for the next character to be entered, with an audible click (known as the "cadence signal") to warn the operator. Operators had to maintain a steady rhythm, and the usual speed of operation was 30 words per minute.
The receiver was also connected to the distributor. The signals from the telegraph line were temporarily stored on a set of five electromagnet
Electromagnet
An electromagnet is a type of magnet in which the magnetic field is produced by the flow of electric current. The magnetic field disappears when the current is turned off...
s, before being decoded to print the corresponding character on paper tape.
Accurate operation of this system depended on the distributor at the transmitting end keeping in synchronization with the one at the receiving end and operators only sending characters when the contacts passed over their allocated sector. This could be achieved at a speed of 30 wpm by strictly observing the "cadence" of rhythm of the system when the distributor gave the operator the use of the line.
First use
The Baudot system was accepted by the French Telegraph Administration during 1875, with the first online tests of his system occurring between Paris and Bordeaux on November 12, 1877. At the end of 1877, the Paris-Rome line, which was about 1700 kilometres (1,056.3 mi), began operating a duplex Baudot.The Baudot apparatus was shown at the Paris Exposition Universelle (1878)
Exposition Universelle (1878)
The third Paris World's Fair, called an Exposition Universelle in French, was held from 1 May through to 10 November 1878. It celebrated the recovery of France after the 1870 Franco-Prussian War.-Construction:...
and won him the Exposition's gold medal, as well as bringing his system to worldwide notice.
Later career
After the first success of his system, Baudot was promoted to Controller during 1880, and was named Inspector-Engineer during 1882.During July, 1887, he conducted successful tests on the Atlantic telegraph cable between Weston-super-Mare
Weston-super-Mare
Weston-super-Mare is a seaside resort, town and civil parish in the unitary authority of North Somerset, which is within the ceremonial county of Somerset, England. It is located on the Bristol Channel coast, south west of Bristol, spanning the coast between the bounding high ground of Worlebury...
and Waterville, Nova Scotia
Waterville, Nova Scotia
Waterville is a Canadian community in Kings County, Nova Scotia.Located on the Cornwallis River, the community is located 15 kilometres west of Kentville and is home to the Waterville/Kings County Municipal Airport, a Michelin tire factory, as well as the provincial youth detention facility.As of...
operated by the Commercial Company, with a double Baudot installed in duplex, the Baudot transmitters and receivers substituted for the recorder.
On August 8, 1890 he established communications between Paris, Vannes
Vannes
Vannes is a commune in the Morbihan department in Brittany in north-western France. It was founded over 2000 years ago.-Geography:Vannes is located on the Gulf of Morbihan at the mouth of two rivers, the Marle and the Vincin. It is around 100 km northwest of Nantes and 450 km south west...
, and Lorient
Lorient
Lorient, or L'Orient, is a commune and a seaport in the Morbihan department in Brittany in north-western France.-History:At the beginning of the 17th century, merchants who were trading with India had established warehouses in Port-Louis...
over a single wire. On January 3, 1894 he installed a triplex apparatus on the telegraph between Paris and Bordeaux that had previously been operating with some difficulty on the Hughes telegraph system. On April 27, 1894, he established communications between the Paris stock exchange and the Milan stock exchange, again over a single wire, using his new invention, the retransmitter. The British Post Office adopted the Baudot system during 1897 for a simplex circuit between London and Paris.
During 1897 the Baudot system was improved by switching to punched tape
Punched tape
Punched tape or paper tape is an obsolete form of data storage, consisting of a long strip of paper in which holes are punched to store data...
, which was prepared offline like the Morse tape used with the Wheatstone
Charles Wheatstone
Sir Charles Wheatstone FRS , was an English scientist and inventor of many scientific breakthroughs of the Victorian era, including the English concertina, the stereoscope , and the Playfair cipher...
and Creed systems. A tape reader, controlled by the Baudot distributor, then replaced the manual keyboard. The tape had five rows of holes for the code, with a sixth row of smaller holes for transporting the tape through the reader mechanism. Baudot’s code was later standardised as International Telegraph Alphabet Number One.
Baudot received little help from the French Telegraph Administration for his system, and often had to fund his own research, even having to sell the gold medal awarded by the 1878 Exposition Universelle during 1880.
The Baudot telegraph system was employed progressively in France, and then was adopted in other countries, Italy being the first to introduce it, in its inland service, during 1887. Holland followed in 1895, Switzerland in 1896, and Austria and Brazil in 1897. The British Post Office adopted it for a simplex circuit between London and Paris during 1897, then used it for more general purposes from 1898. During 1900 it was adopted by Germany, by Russia in 1904, the British West Indies in 1905, Spain in 1906, Belgium in 1909, Argentina in 1912, and Romania in 1913.
Final years
Baudot married Marie Josephine Adelaide Langrognet on January 15, 1890. She died only three months later, on April 9, 1890.Soon after starting work with the telegraph service, Baudot began to suffer physical discomfort and was frequently absent from work for this reason, for as long as a month on one occasion. His condition affected him for the rest of his life, until he died on March 28, 1903, at Sceaux, Hauts-de-Seine
Sceaux, Hauts-de-Seine
Sceaux is a commune in the southern suburbs of Paris, France. It is located from the center of Paris.-Wealth:Sceaux is famous for the Château of Sceaux, set in its large park , designed by André Le Nôtre, measuring...
, near Paris, at the age of 57.
Mimault patent suit
During 1874, French telegraph operator Louis Victor Mimault patented a telegraph system using five separate lines to transmit. After his patent was rejected by the Telegraph Administration, Mimault modified his device to incorporate features from the MeyerBernard Meyer
Bernard Meyer was a French show jumping champion.-Olympic Record:Meyer participated at the 1912 Summer Olympics held in Stockholm, where he obtained a silver medal in Team Jumping with the French team.-References:...
telegraph and obtained a new patent which was also rejected. In the meantime, Baudot had patented his prototype telegraph a few weeks earlier.
Mimault claimed priority of invention over Baudot and brought a patent suit against him during 1877. The Tribunal Civil de la Seine, which reviewed testimony from three experts unconnected with the Telegraph Administration, found in favor of Mimault and accorded him priority of invention of the Baudot code and ruled that Baudot's patents were simply improvements of Mimault's. Neither inventor was satisfied with this judgment, which was eventually rescinded with Mimault being ordered to pay all legal costs.
Mimault became unnerved because of the decision, and after an incident where he shot at and wounded two students of the École Polytechnique
École Polytechnique
The École Polytechnique is a state-run institution of higher education and research in Palaiseau, Essonne, France, near Paris. Polytechnique is renowned for its four year undergraduate/graduate Master's program...
(charges for which were dropped), he demanded a special act to prolong the duration of his patents, 100,000 Francs, and election to the Légion d'honneur. A commission directed by Jules Raynaud (head of telegraph research) rejected his demands. Upon hearing the decision, Mimault shot and killed Raynaud, and was sentenced to 10 years forced labour and 20 years of exile.
Honors
- 1881 - Diploma of Honor from the International Electrical Exposition.
- 1882 - Gold medal from the Société d'Encouragement pour l'Industrie Nationale (SEIN)
- 1889 - Ampere Medal from SEIN
- 1878 - Knight's Cross of the Légion d'honneur
- 1882 - Knight of the Order of Leopold
- 1884 - Knight of the Order of Franz JosephOrder of Franz JosephThe Imperial Austrian Franz Joseph Order was founded by the Emperor Franz Joseph I of Austria on December 2, 1849 on the first anniversary of his assumption of the Imperial Crown...
of Austria. - 1891 - Cross of the Order of the Crown of ItalyOrder of the Crown of ItalyThe Order of the Crown of Italy was founded as a national order in 1868 by King Vittorio Emanuele II, to commemorate the unification of Italy in 1861...
- 1898 - Promoted to Officier of the Légion d'honneur
- 1900 - Knight of the Order of Saints Maurice and LazarusOrder of Saints Maurice and LazarusThe Order of Saints Maurice and Lazarus is an order of chivalry awarded by the House of Savoy, the heads of which were formerly Kings of Italy...
(Italy) - 1901 - Knight of the Order of the Crown of Italy
- A no longer existing street in Paris' 17th Arrondissement was named after Baudot.
- During 1926 the International Telegraph Communications Advisory Committee of the International Telecommunication UnionInternational Telecommunication UnionThe International Telecommunication Union is the specialized agency of the United Nations which is responsible for information and communication technologies...
met in Berlin and immortalised Baudot by designating the baudBaudIn telecommunications and electronics, baud is synonymous to symbols per second or pulses per second. It is the unit of symbol rate, also known as baud rate or modulation rate; the number of distinct symbol changes made to the transmission medium per second in a digitally modulated signal or a...
- shortened from his name - as the unit of telegraph transmission speed.
- During 1949, the French Post Office issued a series of stamps with his portrait. By mistake, the year of his birth was given as 1848, not the correct 1845. The stamp was corrected and reprinted with a different color. However, the erroneous stamps still circulate among philatelists and have greater value than the corrected stamps.