Needle telegraph
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A needle telegraph is an
electrical telegraph Electrical telegraphs were point-to-point text messaging systems, primarily used from the 1840s until the late 20th century. It was the first electrical telecommunications system and the most widely used of a number of early messaging systems ...
that uses indicating needles moved electromagnetically as its means of displaying messages. It is one of the two main types of electromagnetic telegraph, the other being the armature system, as exemplified by the telegraph of
Samuel Morse Samuel Finley Breese Morse (April 27, 1791 – April 2, 1872) was an American inventor and painter. After having established his reputation as a portrait painter, in his middle age Morse contributed to the invention of a single-wire telegraph ...
in the United States. Needle telegraphs were widely used in Europe and the British Empire during the nineteenth century. Needle telegraphs were suggested shortly after
Hans Christian Ørsted Hans Christian Ørsted ( , ; often rendered Oersted in English; 14 August 17779 March 1851) was a Danish physicist and chemist who discovered that electric currents create magnetic fields, which was the first connection found between electricity ...
discovered that electric currents could deflect compass needles in 1820.
Pavel Schilling Baron Pavel Lvovitch Schilling (1786–1837), also known as Paul Schilling, was a Russian military officer and diplomat of Baltic German origin. The majority of his career was spent working for the imperial Russian Ministry of Foreign Affai ...
developed a telegraph using needles suspended by threads. This was intended for installation in Russia for government use, but Schilling died in 1837 before it could be implemented.
Carl Friedrich Gauss Johann Carl Friedrich Gauss (; german: Gauß ; la, Carolus Fridericus Gauss; 30 April 177723 February 1855) was a German mathematician and physicist who made significant contributions to many fields in mathematics and science. Sometimes refer ...
and
Wilhelm Eduard Weber Wilhelm Eduard Weber (; ; 24 October 1804 – 23 June 1891) was a German physicist and, together with Carl Friedrich Gauss, inventor of the first electromagnetic telegraph. Biography of Wilhelm Early years Weber was born in Schlossstrasse in ...
built a telegraph that was used for scientific study and communication between university sites.
Carl August von Steinheil Carl August von Steinheil (12 October 1801 – 14 September 1870) was a German physicist, inventor, engineer and astronomer. Biography Steinheil was born in Ribeauvillé, Alsace. He studied law in Erlangen since 1821. He then studied astronomy i ...
adapted Gauss and Weber's rather cumbersome apparatus for use on various German railways. In England,
William Fothergill Cooke Sir William Fothergill Cooke (4 May 1806 – 25 June 1879) was an English inventor. He was, with Charles Wheatstone, the co-inventor of the Cooke-Wheatstone electrical telegraph, which was patented in May 1837. Together with John Ricardo he fo ...
started building telegraphs, initially based on Schilling's design. With
Charles Wheatstone Sir Charles Wheatstone FRS FRSE DCL LLD (6 February 1802 – 19 October 1875), was an English scientist and inventor of many scientific breakthroughs of the Victorian era, including the English concertina, the stereoscope (a device for di ...
, Cooke produced a much improved design. This was taken up by several railway companies. Cooke's
Electric Telegraph Company The Electric Telegraph Company (ETC) was a British telegraph company founded in 1846 by William Fothergill Cooke and John Ricardo. It was the world's first public telegraph company. The equipment used was the Cooke and Wheatstone telegraph, ...
, formed in 1846, provided the first public telegraph service. The needle telegraphs of the Electric Telegraph Company and their rivals were the standard form of telegraphy for the better part of the nineteenth century in the United Kingdom. They continued in use even after the
Morse telegraph Electrical telegraphs were point-to-point text messaging systems, primarily used from the 1840s until the late 20th century. It was the first electrical telecommunications system and the most widely used of a number of early messaging systems ...
became the official standard in the UK in 1870. Some were still in use well in to the twentieth century.


Early ideas

The history of the needle telegraph began with the landmark discovery, published by
Hans Christian Ørsted Hans Christian Ørsted ( , ; often rendered Oersted in English; 14 August 17779 March 1851) was a Danish physicist and chemist who discovered that electric currents create magnetic fields, which was the first connection found between electricity ...
on 21 April 1820, that an electric current deflected the needle of a nearby compass. Almost immediately, other scholars realised the potential this phenomenon had for building an electric telegraph. The first to suggest this was French mathematician
Pierre-Simon Laplace Pierre-Simon, marquis de Laplace (; ; 23 March 1749 – 5 March 1827) was a French scholar and polymath whose work was important to the development of engineering, mathematics, statistics, physics, astronomy, and philosophy. He summarized ...
. On 2 October,
André-Marie Ampère André-Marie Ampère (, ; ; 20 January 177510 June 1836) was a French physicist and mathematician who was one of the founders of the science of classical electromagnetism, which he referred to as "electrodynamics". He is also the inventor of nu ...
, acting on Laplace's suggestion, sent a paper on this idea to the
Paris Academy of Sciences The French Academy of Sciences (French: ''Académie des sciences'') is a learned society, founded in 1666 by Louis XIV at the suggestion of Jean-Baptiste Colbert, to encourage and protect the spirit of French scientific research. It was at th ...
. Ampère's (theoretical) telegraph had a pair of wires for each letter of the alphabet with a keyboard to control which pair was connected to a battery. At the receiving end, Ampère placed small magnets (needles) under the wires. The effect on the magnet in Ampère's scheme would have been very weak because he did not form the wire into a coil around the needle to multiply the magnetic effect of the current.
Johann Schweigger Johann Salomo Christoph Schweigger (8 April 1779 – 6 September 1857) was a German chemist, physicist, and professor of mathematics born in Erlangen. J.S.C.Schweigger was the son of Friedrich Christian Lorenz Schweigger, professor of theologie ...
had already invented the
galvanometer A galvanometer is an electromechanical measuring instrument for electric current. Early galvanometers were uncalibrated, but improved versions, called ammeters, were calibrated and could measure the flow of current more precisely. A galvanom ...
(in September) using such a multiplier, but Ampère either had not yet got the news, or failed to realise its significance for a telegraph. Peter Barlow investigated Ampère's idea, but thought it would not work. In 1824 he published his results, saying that the effect on the compass was seriously diminished "with only 200 feet of wire". Barlow, and other eminent academics of the time who agreed with him, were criticised by some writers for retarding the development of the telegraph. A decade passed between Ampère's paper being read and the first electromagnetic telegraphs being built.


Development


Schilling telegraph

It was not until 1829 that the idea of applying Schweigger style multipliers to telegraph needles was mooted by
Gustav Theodor Fechner Gustav Theodor Fechner (; ; 19 April 1801 – 18 November 1887) was a German physicist, philosopher, and experimental psychologist. A pioneer in experimental psychology and founder of psychophysics (techniques for measuring the mind), he inspired ...
in Leipzig. Fechner, in other respects following the scheme of Ampère, also suggested a pair of wires for each letter (twenty-four in the German alphabet) laid underground to connect Leipzig with Dresden. Fechner's idea was taken up by William Ritchie of the
Royal Institution of Great Britain The Royal Institution of Great Britain (often the Royal Institution, Ri or RI) is an organisation for scientific education and research, based in the City of Westminster. It was founded in 1799 by the leading British scientists of the age, inc ...
in 1830. Ritchie used twenty-six pairs of wires run across a lecture room as a demonstration of principle. Meanwhile,
Pavel Schilling Baron Pavel Lvovitch Schilling (1786–1837), also known as Paul Schilling, was a Russian military officer and diplomat of Baltic German origin. The majority of his career was spent working for the imperial Russian Ministry of Foreign Affai ...
in Russia constructed a series of telegraphs also using Schweigger multipliers. The exact date that Schilling switched from developing
electrochemical Electrochemistry is the branch of physical chemistry concerned with the relationship between electrical potential difference, as a measurable and quantitative phenomenon, and identifiable chemical change, with the potential difference as an outco ...
telegraphs to needle telegraphs is not known, but Hamel says he showed one in early development to
Tsar Alexander I Alexander I (; – ) was Emperor of Russia from 1801, the first King of Congress Poland from 1815, and the Grand Duke of Finland from 1809 to his death. He was the eldest son of Emperor Paul I and Sophie Dorothea of Württemberg. The son of G ...
who died in 1825. In 1832, Schilling developed the first needle telegraph (and the first electromagnetic telegraph of any kind) intended for practical use.
Tsar Nicholas I , house = Romanov-Holstein-Gottorp , father = Paul I of Russia , mother = Maria Feodorovna (Sophie Dorothea of Württemberg) , birth_date = , birth_place = Gatchina Palace, Gatchina, Russian Empire , death_date = ...
initiated a project to connect
St. Petersburg Saint Petersburg ( rus, links=no, Санкт-Петербург, a=Ru-Sankt Peterburg Leningrad Petrograd Piter.ogg, r=Sankt-Peterburg, p=ˈsankt pʲɪtʲɪrˈburk), formerly known as Petrograd (1914–1924) and later Leningrad (1924–1991), i ...
with
Kronstadt Kronstadt (russian: Кроншта́дт, Kronshtadt ), also spelled Kronshtadt, Cronstadt or Kronštádt (from german: link=no, Krone for "crown" and ''Stadt'' for "city") is a Russian port city in Kronshtadtsky District of the federal city of ...
using Schilling's telegraph, but it was cancelled on Schilling's death in 1837. Schilling's scheme had some drawbacks. Although it used far fewer wires than proposed by Ampère or used by Ritchie, his 1832 demonstration still used eight wires, which made the system expensive to install over very long distances. Schilling's scheme used a bank of six needle instruments which between them displayed a
binary code A binary code represents text, computer processor instructions, or any other data using a two-symbol system. The two-symbol system used is often "0" and "1" from the binary number system. The binary code assigns a pattern of binary digits, also ...
representing a letter of the alphabet. Schilling did devise a code that allowed the letter code to be sent serially to a single needle instrument, but he found that the dignitaries he demonstrated the telegraph to could understand the six-needle version more readily. Transmission speed was very slow on the multi-needle telegraph, perhaps as low as four characters per minute, and even slower on the single-needle version. The reason for this was principally that Schilling had severely
overdamped Damping is an influence within or upon an oscillatory system that has the effect of reducing or preventing its oscillation. In physical systems, damping is produced by processes that dissipate the energy stored in the oscillation. Examples incl ...
the movement of the needles by slowing them with a platinum paddle in a cup of mercury. Schilling's method of mounting the needle by suspending it by a silk thread over the multiplier also had practical difficulties. The instrument had to be carefully levelled before use and could not be moved or disturbed while in use.


Gauss and Weber telegraph

In 1833
Carl Friedrich Gauss Johann Carl Friedrich Gauss (; german: Gauß ; la, Carolus Fridericus Gauss; 30 April 177723 February 1855) was a German mathematician and physicist who made significant contributions to many fields in mathematics and science. Sometimes refer ...
and
Wilhelm Eduard Weber Wilhelm Eduard Weber (; ; 24 October 1804 – 23 June 1891) was a German physicist and, together with Carl Friedrich Gauss, inventor of the first electromagnetic telegraph. Biography of Wilhelm Early years Weber was born in Schlossstrasse in ...
set up an experimental needle telegraph between their laboratory in the
University of Göttingen The University of Göttingen, officially the Georg August University of Göttingen, (german: Georg-August-Universität Göttingen, known informally as Georgia Augusta) is a public research university in the city of Göttingen, Germany. Founded ...
and the university astronomical observatory about a mile and a half away where they were studying the Earth's magnetic field. The line consisted of a pair of copper wires on posts above rooftop height. The receiving instrument they used was a converted laboratory instrument, of which the so called needle was a large bar magnet weighing a pound. In 1834, they replaced the magnet with an even heavier one, variously reported as 25, 30, and 100 pounds. The magnet moved so minutely a telescope was required to observe a scale reflected from it by a mirror. The initial purpose of this line was not telegraphic at all. It was used to confirm the correctness or otherwise of the then recent work of
Georg Ohm Georg Simon Ohm (, ; 16 March 1789 – 6 July 1854) was a German physicist and mathematician. As a school teacher, Ohm began his research with the new electrochemical cell, invented by Italian scientist Alessandro Volta. Using equipment of his o ...
, that is, they were verifying
Ohm's law Ohm's law states that the current through a conductor between two points is directly proportional to the voltage across the two points. Introducing the constant of proportionality, the resistance, one arrives at the usual mathematical equat ...
. They quickly found other uses, the first of which was the synchronisation of clocks in the two buildings. Within a few months, they developed a
telegraph code A telegraph code is one of the character encodings used to transmit information by telegraphy. Morse code is the best-known such code. ''Telegraphy'' usually refers to the electrical telegraph, but telegraph systems using the optical telegraph w ...
that allowed them to send arbitrary messages. Signalling speeds were around seven characters per minute. In 1835, they replaced the batteries of their telegraph with a large magneto-electric apparatus which generated telegraph pulses as the operator moved a coil relative to a bar magnet. This machine was made by
Carl August von Steinheil Carl August von Steinheil (12 October 1801 – 14 September 1870) was a German physicist, inventor, engineer and astronomer. Biography Steinheil was born in Ribeauvillé, Alsace. He studied law in Erlangen since 1821. He then studied astronomy i ...
. The Gauss and Weber telegraph remained in daily service until 1838. In 1836, the
Leipzig–Dresden railway The Leipzig–Dresden line is a German railway line. It was built by the Leipzig–Dresden Railway Company between 1837 and 1839. It was the first long-distance railway and the List of the first German railways to 1870, first railway using only st ...
inquired whether the Gauss and Weber telegraph could be installed on their line. The laboratory instrument was much too cumbersome, and much too slow to be used in this way. Gauss asked Steinheil to develop something more practical for railway use. This he did, producing a compact needle instrument which also emitted sounds while it was receiving messages. The needle struck one of two bells, on the right and left respectively, when it was deflected. The two bells had different tones so that the operator could tell which way the needle had been deflected without constantly watching it. Steinheil first installed his telegraph along five miles of track covering four stations around Munich. In 1838, he was installing another system on the Nuremberg–Fürth railway line. Gauss suggested that he should use the rails as conductors and entirely avoid installing wires. This failed when Steinheil tried it because the rails were not well insulated from the ground, but in the process of this failure, he realised that he could use the ground as one of the conductors. This was the first
earth-return telegraph Earth-return telegraph is the system whereby the return path for the electric current of a telegraph circuit is provided by connection to the earth through an earth electrode. Using earth return saves a great deal of money on installation cost ...
put into service anywhere.


Commercial use


Cooke and Wheatstone telegraph

The most widely used needle system, and the first telegraph of any kind used commercially, was the
Cooke and Wheatstone telegraph The Cooke and Wheatstone telegraph was an early electrical telegraph system dating from the 1830s invented by English inventor William Fothergill Cooke and English scientist Charles Wheatstone. It was a form of needle telegraph, and the first te ...
, employed in Britain and the British Empire in the 19th and early-20th centuries, due to
Charles Wheatstone Sir Charles Wheatstone FRS FRSE DCL LLD (6 February 1802 – 19 October 1875), was an English scientist and inventor of many scientific breakthroughs of the Victorian era, including the English concertina, the stereoscope (a device for di ...
and
William Fothergill Cooke Sir William Fothergill Cooke (4 May 1806 – 25 June 1879) was an English inventor. He was, with Charles Wheatstone, the co-inventor of the Cooke-Wheatstone electrical telegraph, which was patented in May 1837. Together with John Ricardo he fo ...
. The inspiration to build a telegraph came in March 1836 when Cooke saw one of Schilling's needle instruments demonstrated by
Georg Wilhelm Muncke Georg Wilhelm Muncke or Georg Wilhelm Munke (28 November 1772, in Hilligsfeld – 17 October 1847, in Großkmehlen) was a German physicist. From 1797 to 1810 he worked as an administrator at the Georgianum in Hanover. In 1810 he became a pro ...
in a lecture in Heidelberg (although he did not realise that the instrument was due to Schilling). Cooke was supposed to be studying anatomy, but immediately abandoned this and returned to England to develop telegraphy. He initially built a three-needle telegraph, but believing that needle telegraphs would always require multiple wires, he moved to mechanical designs. His first effort was a clockwork telegraph alarm, which later went into service with telegraph companies. He then invented a mechanical telegraph based on a musical snuff box. In this device the detent of the clockwork mechanism was released by the armature of an electromagnet. Cooke carried out this work extremely quickly. The needle telegraph was completed within three weeks, and the mechanical telegraph within six weeks of seeing Muncke's demonstration. Cooke attempted to interest the
Liverpool and Manchester Railway The Liverpool and Manchester Railway (L&MR) was the first inter-city railway in the world. It opened on 15 September 1830 between the Lancashire towns of Liverpool and Manchester in England. It was also the first railway to rely exclusively ...
in his mechanical telegraph for use as railway signalling, but it was rejected in favour of a system using steam whistles. Unsure of how far his telegraph could be made to work, Cooke consulted
Michael Faraday Michael Faraday (; 22 September 1791 – 25 August 1867) was an English scientist who contributed to the study of electromagnetism and electrochemistry. His main discoveries include the principles underlying electromagnetic inducti ...
and
Peter Mark Roget Peter Mark Roget ( ; 18 January 1779 – 12 September 1869) was a British physician, natural theologian, lexicographer and founding secretary of The Portico Library. He is best known for publishing, in 1852, the '' Thesaurus of English Words ...
. They put him in touch with eminent scientist Charles Wheatstone and the two then worked in partnership. Wheatstone suggested using a much improved needle instrument and they then developed a five-needle telegraph. The Cooke and Wheatstone five-needle telegraph was a substantial improvement on the Schilling telegraph. The needle instruments were based on the
galvanometer A galvanometer is an electromechanical measuring instrument for electric current. Early galvanometers were uncalibrated, but improved versions, called ammeters, were calibrated and could measure the flow of current more precisely. A galvanom ...
of
Macedonio Melloni Macedonio Melloni (11 April 1798 – 11 August 1854) was an Italian physicist, notable for demonstrating that radiant heat has similar physical properties to those of light. Life Born at Parma, in 1824 he was appointed professor at the local Uni ...
. They were mounted on a vertical board with the needles centrally pivoted. The needles could be directly observed and Schilling's delicate silk threads were entirely done away with. The system required five wires, a slight reduction on that used by Schilling, partly because the Cooke and Wheatstone system did not require a common wire. Instead of Schilling's binary code, current was sent through one wire to one needle's coil and returned via the coil and wire of another. This scheme was similar to that employed by
Samuel Thomas von Sömmerring Samuel Thomas von Sömmerring (28 January 1755 – 2 March 1830) was a German physician, anatomist, anthropologist, paleontologist and inventor. Sömmerring discovered the macula in the retina of the human eye. His investigations on the brain ...
on his chemical telegraph, but with a much more efficient coding scheme. Sömmerring's code required one wire per
character Character or Characters may refer to: Arts, entertainment, and media Literature * ''Character'' (novel), a 1936 Dutch novel by Ferdinand Bordewijk * ''Characters'' (Theophrastus), a classical Greek set of character sketches attributed to The ...
. Even better, the two needles energised were made to point to a letter of the alphabet. This allowed the apparatus to be used by unskilled operators without the need to learn a code – a key selling point to the railway companies the system was aimed at. Another advantage was that it was much faster at 30 characters per minute. It did not use heavy mercury as the damping fluid, but instead used a vane in air, a much better match for ideal damping. The five-needle telegraph was first put into service with the
Great Western Railway The Great Western Railway (GWR) was a British railway company that linked London with the southwest, west and West Midlands of England and most of Wales. It was founded in 1833, received its enabling Act of Parliament on 31 August 1835 and ran ...
in 1838. However, it was soon dropped in favour of two-needle and single-needle systems. The cost of multiple wires proved to be a more important factor than the cost of training operators. In 1846, Cooke formed the
Electric Telegraph Company The Electric Telegraph Company (ETC) was a British telegraph company founded in 1846 by William Fothergill Cooke and John Ricardo. It was the world's first public telegraph company. The equipment used was the Cooke and Wheatstone telegraph, ...
with
John Lewis Ricardo John Lewis Ricardo (1812 – 2 August 1862) was a British businessman and politician. He was the son of Jacob Ricardo and nephew of the economist David Ricardo. In 1841 he married Catherine Duff (c.1820 – 1869), the daughter of General Sir A ...
, the first company to offer a telegraph service to the public. They continued to sell needle telegraph systems to railway companies for signalling, but they also slowly built a national network for general use by businesses, the press, and the public. Needle telegraphs were officially superseded by the
Morse telegraph Electrical telegraphs were point-to-point text messaging systems, primarily used from the 1840s until the late 20th century. It was the first electrical telecommunications system and the most widely used of a number of early messaging systems ...
when the UK telegraph industry was nationalised in 1870, but some continued in use well in to the twentieth century.


Other systems

The Henley-Foster telegraph was a needle telegraph used by the
British and Irish Magnetic Telegraph Company The British and Irish Magnetic Telegraph Company (also called the Magnetic Telegraph Company or the Magnetic) was founded by John Brett in 1850. The Magnetic was the principal competitor to the largest telegraph company in the United Kingdom, ...
, the main rival to the Electric Telegraph Company. It was invented in 1848 by
William Thomas Henley William Thomas Henley (1814–1882) was a pioneer in the manufacture of telegraph cables. He was working as a porter in Cheapside in 1830, leaving after disputes with his employer, and working at the St Katherine Docks for six years. During those ...
and George Foster. It was made in both single-needle and two-needle forms which in operation were similar to the corresponding Cooke and Wheatstone instruments. The unique feature of this telegraph was that it did not require batteries. The telegraph pulses were generated by coils moving through a magnetic field as the operator worked the handles of the machine to send messages. The Henley-Foster instrument was the most sensitive instrument available in the 1850s. It could consequently be operated over a greater distance and worse quality lines than other systems. The Foy-Breguet telegraph was invented by Alphonse Foy and
Louis-François-Clement Breguet Louis François Clément Breguet (22 December 1804 – 27 October 1883), was a French physicist and watchmaker, noted for his work in the early days of telegraphy Telegraphy is the long-distance transmission of messages where the se ...
in 1842, and used in France. The instrument display was arranged to mimic the French
optical telegraph An optical telegraph is a line of stations, typically towers, for the purpose of conveying textual information by means of visual signals. There are two main types of such systems; the semaphore telegraph which uses pivoted indicator arms and ...
system, with the two needles taking on the same positions as the arms of the Chappe semaphore (the optical system widely used in France). This arrangement meant that operators did not need to be retrained when their telegraph lines were upgraded to the electrical telegraph. The Foy-Breguet telegraph is usually described as a needle telegraph, but electrically it is actually a type of armature telegraph. The needles are not moved by a galvanometer arrangement. They are instead moved by a clockwork mechanism that the operator must keep wound up. The detent of the clockwork is released by an electromagnetic armature which operates on the edges of a received telegraph pulse. According to Stuart M. Hallas, needle telegraphs were in use on the Great Northern Line as late as the 1970s. The
telegraph code A telegraph code is one of the character encodings used to transmit information by telegraphy. Morse code is the best-known such code. ''Telegraphy'' usually refers to the electrical telegraph, but telegraph systems using the optical telegraph w ...
used on these instruments was the
Morse code Morse code is a method used in telecommunication to encode text characters as standardized sequences of two different signal durations, called ''dots'' and ''dashes'', or ''dits'' and ''dahs''. Morse code is named after Samuel Morse, one of ...
. Instead of the usual dots and dashes of different durations, but the same polarity, needle instruments used pulses of the same duration, but opposite polarities to represent the two code elements. This arrangement was commonly used on needle telegraphs and
submarine telegraph cable A submarine communications cable is a cable laid on the sea bed between land-based stations to carry telecommunication signals across stretches of ocean and sea. The first submarine communications cables laid beginning in the 1850s carried tel ...
s in the 19th century after Morse code became the international standard.


Pseudoscience

Sympathetic needles were a supposed 17th century means of instantaneous communication at a distance using magnetised needles. Pointing one needle to a letter of the alphabet was supposed to cause its partner needle to point to the same letter at another location.Phillips, p. 271


References


Bibliography

* Bowers, Brian, ''Sir Charles Wheatstone: 1802–1875'', IEE, 2001 . * Bright, Charles, ''Submarine Telegraphs'', London: Crosby Lockwood, 1898 . * Dawson, Keith, "Electromagnetic telegraphy: early ideas, proposals and apparatus", pp. 113–142 in, Hall, A. Rupert; Smith, Norman (eds), ''History of Technology'', vol. 1, Bloomsbury Publishing, 2016 . * Fahie, John Joseph
''A History of Electric Telegraphy, to the Year 1837''
London: E. & F.N. Spon, 1884 . * Garratt, G.R.M.
"The early history of telegraphy"
''Philips Technical Review'', vol. 26, no. 8/9, pp. 268–284, 21 April 1966. * Hallas, Stuart M.

www.samhallas.co.uk, retrieved an

29 September 2019. * Hubbard, Geoffrey, ''Cooke and Wheatstone: And the Invention of the Electric Telegraph'', Routledge, 2013 . * Huurdeman, Anton A., ''The Worldwide History of Telecommunications'', Wiley, 2003 * Kieve, Jeffrey L., ''The Electric Telegraph: A Social and Economic History'', David and Charles, 1973 . * Mercer, David, ''The Telephone: The Life Story of a Technology'', Greenwood Publishing Group, 2006 . * Phillips, Ronnie J.
"Digital technology and institutional change from the gilded age to modern times: The impact of the telegraph and the internet"
''Journal of Economic Issues'', vol. 34, iss. 2, pp. 267-289, June 2000. * Shaffner, Taliaferro Preston
''The Telegraph Manual''
Pudney & Russell, 1859 . * Taylor, William Bower
''An Historical Sketch of Henry's Contribution to the Electro-magnetic Telegraph''
Washington: Government Printing Office, 1879 . * Yarotsky, A.V.
"150th anniversary of the electromagnetic telegraph"
''Telecommunication Journal'', vol. 49, no. 10, pp. 709–715, October 1982. ----
"The progress of the telegraph: part VII"
''Nature'', vol. 12, pp. 110–113, 10 June 1875.


External links

*{{commonscat-inline, Needle telegraphs Telegraphy Russian inventions