Electrical telegraph
Electrical telegraphs were point-to-point
Text telegraphy consisted of two or more geographically separated stations, called
Electrical telegraphs were used by the emerging railway companies to develop train control systems, minimizing the chances of trains colliding with each other.[4] This was built around the signalling block system with signal boxes along the line communicating with their neighbouring boxes by telegraphic sounding of single-stroke bells and three-position needle telegraph instruments.
In the 1840s, the electrical telegraph superseded
Beginning in 1850, submarine telegraph cables allowed for the first rapid communication between continents. Electrical telegraph networks permitted people and commerce to transmit messages across both continents and oceans almost instantly, with widespread social and economic impacts. c. 1894, the electric telegraph led to Guglielmo Marconi's invention of wireless telegraphy, the first means of radiowave telecommunication.[5]
In the early 20th century, manual telegraphy was slowly replaced by teleprinter networks. Increasing use of the telephone pushed telegraphy into a few specialist uses. Use by the general public was mainly special occasion telegram greetings. The rise of the Internet and usage of email in the 1990s largely put an end to dedicated telegraphy networks.
History
Precursors
Prior to the electric telegraph, visual systems were used, including beacons, smoke signals, flag semaphore, and optical telegraphs for visual signals to communicate over distances of land.[6]
An auditory predecessor was West African talking drums. In the 19th century, Yoruba drummers used talking drums to mimic human tonal language[7][8] to communicate complex messages - usually regarding news of birth, ceremonies, and military conflict - over 4-5 mile distances.[9]
Early work
From
In 1753, an anonymous writer in the
In 1774, Georges-Louis Le Sage realised an early electric telegraph. The telegraph had a separate wire for each of the 26 letters of the alphabet and its range was only between two rooms of his home.[14]
In 1800,
Another very early experiment in electrical telegraphy was an "electrochemical telegraph" created by the
Hans Christian Ørsted discovered in 1820 that an electric current produces a magnetic field that will deflect a compass needle. In the same year Johann Schweigger invented the galvanometer, with a coil of wire around a compass, that could be used as a sensitive indicator for an electric current.[16] Also that year, André-Marie Ampère suggested that telegraphy could be achieved by placing small magnets under the ends of a set of wires, one pair of wires for each letter of the alphabet. He was apparently unaware of Schweigger's invention at the time, which would have made his system much more sensitive. In 1825, Peter Barlow tried Ampère's idea but only got it to work over 200 feet (61 m) and declared it impractical. In 1830 William Ritchie improved on Ampère's design by placing the magnetic needles inside a coil of wire connected to each pair of conductors. He successfully demonstrated it, showing the feasibility of the electromagnetic telegraph, but only within a lecture hall.[17]
In 1825, William Sturgeon invented the electromagnet, with a single winding of uninsulated wire on a piece of varnished iron, which increased the magnetic force produced by electric current. Joseph Henry improved it in 1828 by placing several windings of insulated wire around the bar, creating a much more powerful electromagnet which could operate a telegraph through the high resistance of long telegraph wires.[18] During his tenure at The Albany Academy from 1826 to 1832, Henry first demonstrated the theory of the 'magnetic telegraph' by ringing a bell through one-mile (1.6 km) of wire strung around the room in 1831.[19]
In 1835, Joseph Henry and Edward Davy independently invented the mercury dipping electrical relay, in which a magnetic needle is dipped into a pot of mercury when an electric current passes through the surrounding coil.[20][21][22] In 1837, Davy invented the much more practical metallic make-and-break relay which became the relay of choice in telegraph systems and a key component for periodically renewing weak signals.[23] Davy demonstrated his telegraph system in Regent's Park in 1837 and was granted a patent on 4 July 1838.[24] Davy also invented a printing telegraph which used the electric current from the telegraph signal to mark a ribbon of calico infused with potassium iodide and calcium hypochlorite.[25]
First working systems
This section needs additional citations for verification. (January 2021) |
The first working telegraph was built by the English inventor
The
On 21 October 1832, Schilling managed a short-distance transmission of signals between two telegraphs in different rooms of his apartment. In 1836, the British government attempted to buy the design but Schilling instead accepted overtures from
In 1833,
At first, Gauss and Weber used the telegraph to coordinate time, but soon they developed other signals and finally, their own alphabet. The alphabet was encoded in a binary code that was transmitted by positive or negative voltage pulses which were generated by means of moving an induction coil up and down over a permanent magnet and connecting the coil with the transmission wires by means of the commutator. The page of Gauss' laboratory notebook containing both his code and the first message transmitted, as well as a replica of the telegraph made in the 1850s under the instructions of Weber are kept in the faculty of physics at the University of Göttingen, in Germany.
Gauss was convinced that this communication would be of help to his kingdom's towns. Later in the same year, instead of a
By 1837, William Fothergill Cooke and Charles Wheatstone had co-developed a telegraph system which used a number of needles on a board that could be moved to point to letters of the alphabet. Any number of needles could be used, depending on the number of characters it was required to code. In May 1837 they patented their system. The patent recommended five needles, which coded twenty of the alphabet's 26 letters.
Commercial telegraphy
Cooke and Wheatstone system
The first commercial electrical telegraph was the
Wheatstone ABC telegraph
Wheatstone developed a practical alphabetical system in 1840 called the A.B.C. System, used mostly on private wires. This consisted of a "communicator" at the sending end and an "indicator" at the receiving end. The communicator consisted of a circular dial with a pointer and the 26 letters of the alphabet (and four punctuation marks) around its circumference. Against each letter was a key that could be pressed. A transmission would begin with the pointers on the dials at both ends set to the start position. The transmitting operator would then press down the key corresponding to the letter to be transmitted. In the base of the communicator was a magneto actuated by a handle on the front. This would be turned to apply an alternating voltage to the line. Each half cycle of the current would advance the pointers at both ends by one position. When the pointer reached the position of the depressed key, it would stop and the magneto would be disconnected from the line. The communicator's pointer was geared to the magneto mechanism. The indicator's pointer was moved by a polarised electromagnet whose armature was coupled to it through an escapement. Thus the alternating line voltage moved the indicator's pointer on to the position of the depressed key on the communicator. Pressing another key would then release the pointer and the previous key, and re-connect the magneto to the line.[45] These machines were very robust and simple to operate, and they stayed in use in Britain until well into the 20th century.[46][47]
Morse system
The Morse system uses a single wire between offices. At the sending station, an operator taps on a switch called a telegraph key, spelling out text messages in Morse code. Originally, the armature was intended to make marks on paper tape, but operators learned to interpret the clicks and it was more efficient to write down the message directly.
In 1851, a conference in Vienna of countries in the German-Austrian Telegraph Union (which included many central European countries) adopted the Morse telegraph as the system for international communications.
In the United States, the Morse/Vail telegraph was quickly deployed in the two decades following the first demonstration in 1844. The overland telegraph connected the west coast of the continent to the east coast by 24 October 1861, bringing an end to the Pony Express.[51]
Foy–Breguet system
France was slow to adopt the electrical telegraph, because of the extensive
Expansion
As well as the rapid expansion of the use of the telegraphs along the railways, they soon spread into the field of mass communication with the instruments being installed in post offices. The era of mass personal communication had begun. Telegraph networks were expensive to build, but financing was readily available, especially from London bankers. By 1852, National systems were in operation in major countries:[53][54]
Country | Company or system | Miles or kilometers of wire |
ref |
---|---|---|---|
United States | 20 companies | 23,000 mi or 37,000 km | [55] |
United Kingdom | Magnetic Telegraph Company , and others |
2,200 mi or 3,500 km | [56] |
Prussia | Siemens system | 1,400 mi or 2,300 km | |
Austria | Siemens system | 1,000 mi or 1,600 km | |
Canada | 900 mi or 1,400 km | ||
France | optical systems dominant | 700 mi or 1,100 km |
The New York and Mississippi Valley Printing Telegraph Company, for example, was created in 1852 in Rochester, New York and eventually became the Western Union Telegraph Company.[57] Although many countries had telegraph networks, there was no worldwide interconnection. Message by post was still the primary means of communication to countries outside Europe.
A letter by post from London took | |
---|---|
days | to reach[58] |
12 | New York in the United States |
13 | Alexandria in Egypt |
19 | Constantinople in Ottoman Turkey |
33 | Bombay in India (west coast of India) |
44 | Calcutta in Bengal (east coast of India) |
45 | Singapore |
57 | Shanghai in China |
73 | Sydney in Australia |
Telegraphy was introduced in Central Asia during the 1870s.[59]
Telegraphic improvements
A continuing goal in telegraphy was to reduce the cost per message by reducing hand-work, or increasing the sending rate. There were many experiments with moving pointers, and various electrical encodings. However, most systems were too complicated and unreliable. A successful expedient to reduce the cost per message was the development of
The first system that did not require skilled technicians to operate was Charles Wheatstone's ABC system in 1840 in which the letters of the alphabet were arranged around a clock-face, and the signal caused a needle to indicate the letter. This early system required the receiver to be present in real time to record the message and it reached speeds of up to 15 words a minute.
In 1846, Alexander Bain patented a chemical telegraph in Edinburgh. The signal current moved an iron pen across a moving paper tape soaked in a mixture of ammonium nitrate and potassium ferrocyanide, decomposing the chemical and producing readable blue marks in Morse code. The speed of the printing telegraph was 16 and a half words per minute, but messages still required translation into English by live copyists. Chemical telegraphy came to an end in the US in 1851, when the Morse group defeated the Bain patent in the US District Court.[60]
For a brief period, starting with the New York–Boston line in 1848, some telegraph networks began to employ sound operators, who were trained to understand Morse code aurally. Gradually, the use of sound operators eliminated the need for telegraph receivers to include register and tape. Instead, the receiving instrument was developed into a "sounder", an electromagnet that was energized by a current and attracted a small iron lever. When the sounding key was opened or closed, the sounder lever struck an anvil. The Morse operator distinguished a dot and a dash by the short or long interval between the two clicks. The message was then written out in long-hand.[61]
Royal Earl House developed and patented a letter-printing telegraph system in 1846 which employed an alphabetic keyboard for the transmitter and automatically printed the letters on paper at the receiver,[62] and followed this up with a steam-powered version in 1852.[63] Advocates of printing telegraphy said it would eliminate Morse operators' errors. The House machine was used on four main American telegraph lines by 1852. The speed of the House machine was announced as 2600 words an hour.[64]
David Edward Hughes invented the printing telegraph in 1855; it used a keyboard of 26 keys for the alphabet and a spinning type wheel that determined the letter being transmitted by the length of time that had elapsed since the previous transmission. The system allowed for automatic recording on the receiving end. The system was very stable and accurate and became accepted around the world.[65]
The next improvement was the Baudot code of 1874. French engineer Émile Baudot patented a printing telegraph in which the signals were translated automatically into typographic characters. Each character was assigned a five-bit code, mechanically interpreted from the state of five on/off switches. Operators had to maintain a steady rhythm, and the usual speed of operation was 30 words per minute.[66]
By this point, reception had been automated, but the speed and accuracy of the transmission were still limited to the skill of the human operator. The first practical automated system was patented by Charles Wheatstone. The message (in Morse code) was typed onto a piece of perforated tape using a keyboard-like device called the 'Stick Punch'. The transmitter automatically ran the tape through and transmitted the message at the then exceptionally high speed of 70 words per minute.
Teleprinters
This section needs additional citations for verification. (January 2020) |
An early successful teleprinter was invented by Frederick G. Creed. In Glasgow he created his first keyboard perforator, which used compressed air to punch the holes. He also created a reperforator (receiving perforator) and a printer. The reperforator punched incoming Morse signals onto paper tape and the printer decoded this tape to produce alphanumeric characters on plain paper. This was the origin of the Creed High Speed Automatic Printing System, which could run at an unprecedented 200 words per minute. His system was adopted by the Daily Mail for daily transmission of the newspaper contents.
With the invention of the
In the 1930s, teleprinters were produced by Teletype in the US, Creed in Britain and Siemens in Germany.
By 1935, message routing was the last great barrier to full automation. Large telegraphy providers began to develop systems that used
The first wide-coverage Telex network was implemented in Germany during the 1930s[67] as a network used to communicate within the government.
At the rate of 45.45 (±0.5%)
Automatic teleprinter exchange service was introduced into Canada by
The harmonic telegraph
The most expensive aspect of a telegraph system was the installation – the laying of the wire, which was often very long. The costs would be better covered by finding a way to send more than one message at a time through the single wire, thus increasing revenue per wire. Early devices included the
One approach was to have resonators of several different frequencies act as carriers of a modulated on-off signal. This was the harmonic telegraph, a form of frequency-division multiplexing. These various frequencies, referred to as harmonics, could then be combined into one complex signal and sent down the single wire. On the receiving end, the frequencies would be separated with a matching set of resonators.
With a set of frequencies being carried down a single wire, it was realized that the human voice itself could be transmitted electrically through the wire. This effort led to the invention of the telephone. (While the work toward packing multiple telegraph signals onto one wire led to telephony, later advances would pack multiple voice signals onto one wire by increasing the bandwidth by modulating frequencies much higher than human hearing. Eventually, the bandwidth was widened much further by using laser light signals sent through fiber optic cables. Fiber optic transmission can carry 25,000 telephone signals simultaneously down a single fiber.[69])
Oceanic telegraph cables
Soon after the first successful telegraph systems were operational, the possibility of transmitting messages across the sea by way of
The
Australia was first linked to the rest of the world in October 1872 by a submarine telegraph cable at Darwin.[75] This brought news reports from the rest of the world.[76] The telegraph across the Pacific was completed in 1902, finally encircling the world.
From the 1850s until well into the 20th century, British submarine cable systems dominated the world system. This was set out as a formal strategic goal, which became known as the All Red Line.[77] In 1896, there were thirty cable laying ships in the world and twenty-four of them were owned by British companies. In 1892, British companies owned and operated two-thirds of the world's cables and by 1923, their share was still 42.7 percent.[78]
Cable and Wireless Company
Cable & Wireless was a British telecommunications company that traced its origins back to the 1860s, with Sir John Pender as the founder,[79] although the name was only adopted in 1934. It was formed from successive mergers including:
- The Falmouth, Malta, Gibraltar Telegraph Company
- The British Indian Submarine Telegraph Company
- The Marseilles, Algiers and Malta Telegraph Company
- The Eastern Telegraph Company[80]
- The Eastern Extension Australasia and China Telegraph Company
- The Eastern and Associated Telegraph Companies[81]
Telegraphy and longitude
Main article § Section: History of longitude § Land surveying and telegraphy.
The telegraph was very important for sending time signals to determine longitude, providing greater accuracy than previously available. Longitude was measured by comparing local time (for example local noon occurs when the sun is at its highest above the horizon) with absolute time (a time that is the same for an observer anywhere on earth). If the local times of two places differ by one hour, the difference in longitude between them is 15° (360°/24h). Before telegraphy, absolute time could be obtained from astronomical events, such as
The idea of using the telegraph to transmit a time signal for longitude determination was suggested by François Arago to Samuel Morse in 1837,[82] and the first test of this idea was made by Capt. Wilkes of the U.S. Navy in 1844, over Morse's line between Washington and Baltimore.[83] The method was soon in practical use for longitude determination, in particular by the U.S. Coast Survey, and over longer and longer distances as the telegraph network spread across North America and the world, and as technical developments improved accuracy and productivity[84]: 318–330 [85]: 98–107
The "telegraphic longitude net"[86] soon became worldwide. Transatlantic links between Europe and North America were established in 1866 and 1870. The US Navy extended observations into the West Indies and Central and South America with an additional transatlantic link from South America to Lisbon between 1874 and 1890.[87][88][89][90] British, Russian and US observations created a chain from Europe through Suez, Aden, Madras, Singapore, China and Japan, to Vladivostok, thence to Saint Petersburg and back to Western Europe.[91]
Australia was linked to Singapore via Java in 1871[92] and the web circled the globe in 1902 with the connection of Australia and New Zealand to Canada via the All Red Line. The double determination of longitudes from east to west and from west to east agreed within one second of arc (1⁄15 second of time – less than 30 metres).[93]
Telegraphy in war
The ability to send telegrams brought obvious advantages to those conducting war. Secret messages were encoded, so interception alone would not be sufficient for the opposing side to gain an advantage. There were also geographical constraints on intercepting the telegraph cables that improved security, however once radio telegraphy was developed interception became far more widespread.
Crimean War
The Crimean War was one of the first conflicts to use telegraphs and was one of the first to be documented extensively. In 1854, the government in London created a military Telegraph Detachment for the Army commanded by an officer of the Royal Engineers. It was to comprise twenty-five men from the Royal Corps of Sappers & Miners trained by the Electric Telegraph Company to construct and work the first field electric telegraph.[94]
Journalistic recording of the war was provided by William Howard Russell (writing for The Times newspaper) with photographs by Roger Fenton.[95] News from war correspondents kept the public of the nations involved in the war informed of the day-to-day events in a way that had not been possible in any previous war. After the French extended the telegraph to the coast of the Black Sea in late 1854, the news reached London in two days. When the British laid an underwater cable to the Crimean peninsula in April 1855, news reached London in a few hours. The daily news reports energised public opinion, which brought down the government and led to Lord Palmerston becoming prime minister.[96]
American Civil War
During the American Civil War the telegraph proved its value as a tactical, operational, and strategic communication medium and an important contributor to Union victory.[97] By contrast the Confederacy failed to make effective use of the South's much smaller telegraph network. Prior to the War the telegraph systems were primarily used in the commercial sector. Government buildings were not inter-connected with telegraph lines, but relied on runners to carry messages back and forth.[98] Before the war the Government saw no need to connect lines within city limits, however, they did see the use in connections between cities. Washington D.C. being the hub of government, it had the most connections, but there were only a few lines running north and south out of the city.[98] It was not until the Civil War that the government saw the true potential of the telegraph system. Soon after the shelling of Fort Sumter, the South cut telegraph lines running into D.C., which put the city in a state of panic because they feared an immediate Southern invasion.[99][98]
Within 6 months of the start of the war, the U.S. Military Telegraph Corps (USMT) had laid approximately 300 miles (480 km) of line. By war's end they had laid approximately 15,000 miles (24,000 km) of line, 8,000 for military and 5,000 for commercial use, and had handled approximately 6.5 million messages. The telegraph was not only important for communication within the armed forces, but also in the civilian sector, helping political leaders to maintain control over their districts.[99]
Even before the war, the
The telegraph system still had its flaws. The USMT, while the main source of telegraphers and cable, was still a civilian agency. Most operators were first hired by the telegraph companies and then contracted out to the War Department. This created tension between generals and their operators. One source of irritation was that USMT operators did not have to follow military authority. Usually they performed without hesitation, but they were not required to, so
First World War
During World War I, Britain's telegraph communications were almost completely uninterrupted, while it was able to quickly cut Germany's cables worldwide.[100] The British government censored telegraph cable companies in an effort to root out espionage and restrict financial transactions with Central Powers nations.[101] British access to transatlantic cables and its codebreaking expertise led to the Zimmermann Telegram incident that contributed to the US joining the war.[102] Despite British acquisition of German colonies and expansion into the Middle East, debt from the war led to Britain's control over telegraph cables to weaken while US control grew.[103]
Second World War
World War II revived the 'cable war' of 1914–1918. In 1939, German-owned cables across the Atlantic were cut once again, and, in 1940, Italian cables to South America and Spain were cut in retaliation for Italian action against two of the five British cables linking Gibraltar and Malta. Electra House, Cable & Wireless's head office and central cable station, was damaged by German bombing in 1941.
End of the telegraph era
In America, the end of the telegraph era can be associated with the fall of the Western Union Telegraph Company. Western Union was the leading telegraph provider for America and was seen as the best competition for the National Bell Telephone Company. Western Union and Bell were both invested in telegraphy and telephone technology. Western Union's decision to allow Bell to gain the advantage in telephone technology was the result of Western Union's upper management's failure to foresee the surpassing of the telephone over the, at the time, dominant telegraph system. Western Union soon lost the legal battle for the rights to their telephone copyrights. This led to Western Union agreeing to a lesser position in the telephone competition, which in turn led to the lessening of the telegraph.[99]
While the telegraph was not the focus of the legal battles that occurred around 1878, the companies that were affected by the effects of the battle were the main powers of telegraphy at the time. Western Union thought that the agreement of 1878 would solidify telegraphy as the long-range communication of choice. However, due to the underestimates of telegraph's future[further explanation needed] and poor contracts, Western Union found itself declining.[99] AT&T acquired working control of Western Union in 1909 but relinquished it in 1914 under threat of antitrust action. AT&T bought Western Union's electronic mail and Telex businesses in 1990.
Although commercial "telegraph" services are still available in many countries, transmission is usually done via a computer network rather than a dedicated wired connection.
See also
- 92 Code
- Aurora#Historically significant events
- American Telephone and Telegraph Company(AT&T)
- Bell Canada
- Geomagnetically induced current
- Great Northern Telegraph Company
- Neutral direct-current telegraph system
- Western Electric Company
References
- ISSN 1478-0542.
- ^ Kieve 1973, p. 13.
- ^ Roberts, Steven. "Distant Writing: A History of the Telegraph Companies in Britain between 1838 and 1868: 2. Introduction".
Using these discoveries a number of inventors or rather 'adapters' appeared, taking this new knowledge, transforming it into useful ideas with commercial utility; the first of these 'products' was the use of electricity to transmit information between distant points, the electric telegraph.
- ISBN 978-0-7110-3536-2.
- ^ Moss, Stephen (10 July 2013), "Final telegram to be sent. STOP", The Guardian: International Edition
- ISBN 0819562599.
- ISBN 9780521033404.
- ^ Odden, David (1995). "Tone: African languages". In J. Goldsmith (ed.). Handbook of Phonological Theory. Oxford: Basil Blackwell.
- ^ Ong, Walter (1977). Interfaces of the Word: Studies in the Evolution of Consciousness and Culture. p. 101.
- ^ Fahie
- LCCN 64-20875
- ^ Holzmann & Pehrson, p. 203
- ^ Electromagnetic Telegraph – Invented by Baron Pavel Schilling
- ^ Prevost, 1805, pp. 176–178
- ^ a b Jones 1999.
- ^ M. (10 December 2014). Schweigger Multiplier – 1820. Retrieved 7 February 2018, from https://nationalmaglab.org/education/magnet-academy/history-of-electricity-magnetism/museum/schweigger-multiplier
- ^ Fahie, pp. 302–306
- ^ R. V. G. Menon (2011). Technology and Society. India: Dorling Kindersley.
- ^ Henry Pitt Phelps (1884). The Albany Hand-book: A Strangers' Guide and Residents' Manual. Albany: Brandow & Barton. p. 6.
- ^ Gibberd 1966.
- ^ "Joseph Henry: Inventor of the Telegraph? Smithsonian Institution". Archived from the original on 26 June 2006. Retrieved 29 June 2006.
- ^ Thomas Coulson (1950). Joseph Henry: His Life and Work. Princeton: Princeton University Press.
- ISBN 0905118839.
- ^ "Edward Davy". Australian Science Archives Project. Retrieved 7 June 2012.
- ^ Kieve 1973, pp. 23–24.
- ^ Appleyard, R. (1930). Pioneers of Electrical Communication. Macmillan.
- S2CID 113256632.
- ^ Ronalds, Francis (1823). Descriptions of an Electrical Telegraph and of some other Electrical Apparatus. London: Hunter.
- .
- ISBN 978-1-78326-917-4.
- ^ a b Fahie 1884, pp. 307–325.
- ^ Huurdeman 2003, p. 54.
- ^ Calvert 2008.
- ^ Howe, p. 7
- ^ History.com Staff (2009), Morse Code & the Telegraph, A+E Networks
- ^ "The telegraphic age dawns". BT Group Connected Earth Online Museum. Archived from the original on 19 February 2013. Retrieved 1 December 2010.
- ^ a b Bowers, page 129
- ^ Huurdeman 2003, p. 67.
- ^ Huurdeman 2003, pp. 67–68.
- ^ Beauchamp 2001, p. 35.
- ^ Huurdeman 2003, p. 69.
- ^ Huurdeman 2003, pp. 67–69.
- ^ Nichols, John (1967). The Gentleman's magazine, Volumes 282–283. p. 545. University of California
- ^ Paul Atterbury. "Victorian Technology". BBC.
- ^ "Telegraph – A working ABC telegraph from prof. Ch. Wheatstone". YouTube. 5 June 2018.
- ^ Freebody, J. W. (1958), "Historical Survey of Telegraphy", Telegraphy, London: Sir Isaac Pitman & Sons, Ltd., pp. 30, 31
- ^ Hobbs, Alan G.; Hallas, Sam. "A Short History of Telegraphy".
- OCLC 60717772.
- ISBN 0786418087.
- ISBN 978-1107039193.
- ^ Today in History – 24 October, The Transcontinental Telegraph and the End of the Pony Express, Library of Congress, retrieved 3 February 2017.
- ^ Holzmann & Pehrson, pp. 93–94
- ^ Christine Rider, ed., Encyclopedia of the Age of the Industrial Revolution, 1700–1920 (2007) 2:440.
- ^ Shaffner, Taliaferro Preston (1867). "The Telegraph Manual: A Complete History and Description of the Semaphoric, Electric and Magnetic Telegraphs of Europe, Asia, Africa, and America, Ancient and Modern: with Six Hundred and Twenty-five Illustrations".
- ^ Richard B. Du Boff, "Business Demand and the Development of the Telegraph in the United States, 1844–1860." \\Business History Review 54#4 (1980): 459–479.
- ^ John Liffen, "The Introduction of the Electric Telegraph in Britain, a Reappraisal of the Work of Cooke and Wheatstone." International Journal for the History of Engineering & Technology (2013).
- S2CID 14674389.
Article 11
- ^ Roberts, Steven (2012), A History of the Telegraph Companies in Britain between 1838–1868, retrieved 8 May 2017
- ISBN 0-520-21356-4.
- ISBN 9780865544185.
- ISBN 9780865544185.
- ^ "Royal Earl House Printing-Telegraph Patent #4464, 1846". Retrieved 25 April 2014.
- ^ "Royal Earl House Steam-Powered Printing-Telegraph Patent #9505, 1852". Retrieved 25 April 2014.
- ISBN 9780865544185.
- ^ "David Edward Hughes". Clarkson University. 14 April 2007. Archived from the original on 22 April 2008. Retrieved 29 September 2010.
- ^ Beauchamp 2001, pp. 394–395.
- ^ "Telegraphy and Telex". Archived from the original on 26 July 2019. Retrieved 25 March 2021.
- ^ Phillip R. Easterlin, "Telex in New York", Western Union Technical Review, April 1959: 45
- ^ "How does fiber optics work?". 11 June 2006.
- ^ a b Haigh, K R (1968). Cable Ships and Submarine Cables. London: Adlard Coles Ltd. pp. 26–27.
- ^ Bright, Charles (1898). Submarine telegraphs [microform] : their history, construction, and working : founded in part on Wünschendorff's 'Traité de télé graphie sous-marine. Canadiana.org. London: C. Lockwood. p. 251.
- ISBN 9781855733015.
- JSTOR 20762437.
- S2CID 114607440.
- ISBN 9780745635118.
- ^ Conley, David; Lamble, Stephen (2006). The Daily Miracle: An introduction to Journalism (3 ed.). Australia: Oxford University Press. pp. 305–307.
- JSTOR 563928.
- S2CID 153560358.
- ^ "Sir John Pender".
- ^ "Evolution of Eastern Telegraph Company".
- ^ "Origins of the Eastern & Associated Telegraph Companies".
- ^ Walker, Sears C (1850). "Report on the experience of the Coast Survey in regard to telegraph operations, for determination of longitude &c". American Journal of Science and Arts. 10 (28): 151–160.
- ^ Briggs, Charles Frederick; Maverick, Augustus (1858). The Story of the Telegraph, and a History of the Great Atlantic Cable: A Complete Record of the Inception, Progress, and Final Success of that Undertaking: a General History of Land and Oceanic Telegraphs: Descriptions of Telegraphic Apparatus, and Biographical Sketches of the Principal Persons Connected with the Great Work. New York: Rudd & Carleton.
- ^ Loomis, Elias (1856). The recent progress of astronomy, especially in the United States. Third Edition. New York: Harper and Brothers.
- ISBN 978-1-57003-801-3.
- doi:10.1086/102749.
- ^ Green, Francis Matthews (1877). Report on the telegraphic determination of differences of longitude in the West Indies and Central America. Washington: US Hydrographic Office.
- ^ Green, Francis Matthews (1880). Telegraphic determination of longitudes on the east coast of South America embracing the meridians of Lisbon, Madeira, St. Vincent, Pernambuco, Bahia, Rio de Janeiro, Montevideo, Buenos Ayres, and Para, with the latitude of the several stations. Washington: US Hydrographic Office.
- ^ Davis, Chales Henry; Norris, John Alexander (1885). Telegraphic Determination of Longitudes in Mexico and Central America and on the West Coast of South America: Embracing the Meridians of Vera Cruz; Guatemala; La Libertad; Salvador; Paita; Lima; Arica; Valparaiso; and the Argentine National Observatory at Cordoba; with the Latitudes of the Several Sea-coast Stations. Washington: US Hydrographic Office.
- ^ Norris, John Alexander; Laird, Charles; Holcombe, John H.L.; Garrett, Le Roy M. (1891). Telegraphic determination of longitudes in Mexico, Central America, the West Indies, and on the north coast of South America, embracing the meridians of Coatzacoalcos; Salina Cruz; La Libertad; San Juan del Sur; St. Nicolas Mole; Port Plata; Santo Domingo; Curacao; and La Guayra, with the latitudes of the several stations. Washington: US Hydrographic Office.
- ^ Green, Francis Mathews; Davis, Charles Henry; Norris, John Alexander (1883). Telegraphic Determination of Longitudes in Japan, China, and the East Indies: Embracing the Meridians of Yokohama, Nagasaki, Wladiwostok, Shanghai, Amoy, Hong-Kong, Manila, Cape St. James, Singapore, Batavia, and Madras, with the Latitude of the Several Stations. Washington: US Hydrographic Office.
- S2CID 149205560.
- Bibcode:1924JRASC..18....1S.
- ^ Roberts, Steven (2012), Distant Writing A History of Telegraph Companies in Britain between 1838 and 1868: 16. Telegraph at War 1854 – 1868
- ^ Figes 2010, pp. 306–09.
- ^ Figes 2010, pp. 304–11.
- ^ Hochfelder, David (2019), Essential Civil WAR Curriculum: The Telegraph, Virginia Center for Civil War Studies at Virginia Tech
- ^ a b c Schwoch 2018.
- ^ a b c d e f Hochfelder 2012.
- ^ Kennedy 1971.
- S2CID 153879238.
- ^ "The telegram that brought America into the First World War". BBC History Magazin e. 17 January 2017.
- S2CID 144107714.
- ^ World War II: German-occupied Europe, Encyclopaedia Britannica
- ^ Copeland 2006, pp. 1–6.
Bibliography
- Beauchamp, Ken (2001). History of Telegraphy. London: The Institution of Electrical Engineers. ISBN 978-0-85296-792-8.
- Bowers, Brian, Sir Charles Wheatstone: 1802–1875, IET, 2001 ISBN 0852961030
- Calvert, J. B. (2008). "The Electromagnetic Telegraph".
- ISBN 978-0-19-284055-4.
- Fahie, John Joseph (1884). A History of Electric Telegraphy, to the Year 1837. London: E. & F.N. Spon. OCLC 559318239.
- Figes, Orlando (2010). ISBN 978-0-7139-9704-0.
- Gibberd, William (1966). Australian Dictionary of Biography: Edward Davy.
- Hochfelder, David (2012). The Telegraph in America, 1832–1920. Johns Hopkins University Press. pp. 6–17, 138–141. ISBN 9781421407470.
- Holzmann, Gerard J.; Pehrson, Björn, The Early History of Data Networks, Wiley, 1995 ISBN 0818667826
- Huurdeman, Anton A. (2003). The Worldwide History of Telecommunications. Wiley-Blackwell. ISBN 978-0471205050.
- Jones, R. Victor (1999). Samuel Thomas von Sömmering's "Space Multiplexed" Electrochemical Telegraph (1808–1810). Archived from the original on 11 October 2012. Retrieved 1 May 2009. Attributed to Michaelis, Anthony R. (1965), From semaphore to satellite, Geneva: International Telecommunication Union
- Kennedy, P. M. (October 1971). "Imperial Cable Communications and Strategy, 1870–1914". The English Historical Review. 86 (341): 728–752. JSTOR 563928.
- Kieve, Jeffrey L. (1973). The Electric Telegraph: A Social and Economic History. David and Charles. OCLC 655205099.
- Mercer, David, The Telephone: The Life Story of a Technology, Greenwood Publishing Group, 2006 ISBN 031333207X
- Schwoch, James (2018). Wired into Nature: The Telegraph and the North American Frontier. University of Illinois Press. ISBN 978-0252041778.
Further reading
- Cooke, W.F., The Electric Telegraph, Was it invented by Prof. Wheatstone?, London 1856.
- Gray, Thomas (1892). "The Inventors of the Telegraph And Telephone". Annual Report of the Board of Regents of the Smithsonian Institution. 71: 639–659. Retrieved 7 August 2009.
- Gauß, C. F., Works, Göttingen 1863–1933.
- Howe, Daniel Walker, What Hath God Wrought: The Transformation of America, 1815–1848, Oxford University Press, 2007 ISBN 0199743797.
- Peterson, M.J. Roots of Interconnection: Communications, Transportation and Phases of the Industrial Revolution, International Dimensions of Ethics Education in Science and Engineering Background Reading, Version 1; February 2008.
- Steinheil, C.A., Ueber Telegraphie, München 1838.
- Yates, JoAnne. The Telegraph's Effect on Nineteenth Century Markets and Firms, Massachusetts Institute of Technology, pp. 149–163.
External links
- Morse Telegraph Club, Inc. (The Morse Telegraph Club is an international non-profit organization dedicated to the perpetuation of the knowledge and traditions of telegraphy.)
- "Transatlantic Cable Communications". Canada's Digital Collections. Archived from the original on 29 August 2005.
- Shilling's telegraph, an exhibit of the A.S. Popov Central Museum of Communications
- History of electromagnetic telegraph
- The first electric telegraphs
- The Dawn of Telegraphy (in Russian)
- Pavel Shilling and his telegraph- article in PCWeek, Russian edition.
- Distant Writing – The History of the Telegraph Companies in Britain between 1838 and 1868
- NASA – Carrington Super Flare Archived 29 March 2010 at the Wayback Machine NASA 6 May 2008
- How Cables Unite The World – a 1902 article about telegraph networks and technology from the magazine The World's Work
- New International Encyclopedia. 1905.
.
- Indiana telegraph and telephone collection, Rare Books and Manuscripts, Indiana State Library
- Wonders of electricity and the elements, being a popular account of modern electrical and magnetic discoveries, magnetism and electric machines, the electric telegraph and the electric light, and the metal bases, salt, and acids from Science History Institute Digital Collections
- The electro magnetic telegraph: with an historical account of its rise, progress, and present condition from Science History Institute Digital Collections