83-553: Sonakanda Fort is a river fort situated in Narayanganj , Bangladesh, on the eastern bank of Shitalakshya River . Though the time of its establishment could not be ascertained, historians believe that the river fort was built by Mir Jumla II , a Subahdar of Bengal under the Mughal Empire , to defend Dhaka and Narayanganj from pirates. Bengal went under the effective control of the Mughal Empire in 1574 AD after
166-474: A Telex was a message sent by a Telex network, a switched network of teleprinters similar to a telephone network. A wirephoto or wire picture was a newspaper picture that was sent from a remote location by a facsimile telegraph . A diplomatic telegram, also known as a diplomatic cable , is a confidential communication between a diplomatic mission and the foreign ministry of its parent country. These continue to be called telegrams or cables regardless of
249-453: A code by itself. The term heliostat is sometimes used as a synonym for heliograph because of this origin. The Colomb shutter ( Bolton and Colomb , 1862) was originally invented to enable the transmission of morse code by signal lamp between Royal Navy ships at sea. The heliograph was heavily used by Nelson A. Miles in Arizona and New Mexico after he took over command (1886) of
332-470: A distance of a quarter of a mile. In the 1890s inventor Nikola Tesla worked on an air and ground conduction wireless electric power transmission system , similar to Loomis', which he planned to include wireless telegraphy. Tesla's experiments had led him to incorrectly conclude that he could use the entire globe of the Earth to conduct electrical energy and his 1901 large scale application of his ideas,
415-446: A distance. This is to be distinguished from semaphore , which merely transmits messages. Smoke signals, for instance, are to be considered semaphore, not telegraph. According to Morse, telegraph dates only from 1832 when Pavel Schilling invented one of the earliest electrical telegraphs. A telegraph message sent by an electrical telegraph operator or telegrapher using Morse code (or a printing telegraph operator using plain text)
498-473: A few days, sometimes taking all day to send a message despite the use of the highly sensitive mirror galvanometer developed by William Thomson (the future Lord Kelvin ) before being destroyed by applying too high a voltage. Its failure and slow speed of transmission prompted Thomson and Oliver Heaviside to find better mathematical descriptions of long transmission lines . The company finally succeeded in 1866 with an improved cable laid by SS Great Eastern ,
581-555: A message was relayed 640 km (400 mi) in four hours. Miles' enemies used smoke signals and flashes of sunlight from metal, but lacked a sophisticated telegraph code. The heliograph was ideal for use in the American Southwest due to its clear air and mountainous terrain on which stations could be located. It was found necessary to lengthen the morse dash (which is much shorter in American Morse code than in
664-493: A modification of surveying equipment ( Gauss , 1821). Various uses of mirrors were made for communication in the following years, mostly for military purposes, but the first device to become widely used was a heliograph with a moveable mirror ( Mance , 1869). The system was used by the French during the 1870–71 siege of Paris , with night-time signalling using kerosene lamps as the source of light. An improved version (Begbie, 1870)
747-606: A natural rubber from the Palaquium gutta tree, after William Montgomerie sent samples to London from Singapore in 1843. The new material was tested by Michael Faraday and in 1845 Wheatstone suggested that it should be used on the cable planned between Dover and Calais by John Watkins Brett . The idea was proved viable when the South Eastern Railway company successfully tested a three-kilometre (two-mile) gutta-percha insulated cable with telegraph messages to
830-546: A number of anachronistic myths related to the river fort that include tragedy and mystery. Narayanganj Narayanganj ( Bengali : নারায়ণগঞ্জ , romanized : Narayongônjo ) is a city in central Bangladesh in the Greater Dhaka area. It is in the Narayanganj District , about 16 km (10 mi) southeast of the capital city of Dhaka . With a population of almost 1 million, it
913-489: A popular means of sending messages once telegraph prices had fallen sufficiently. Traffic became high enough to spur the development of automated systems— teleprinters and punched tape transmission. These systems led to new telegraph codes , starting with the Baudot code . However, telegrams were never able to compete with the letter post on price, and competition from the telephone , which removed their speed advantage, drove
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#1732801967170996-614: A ship off the coast of Folkestone . The cable to France was laid in 1850 but was almost immediately severed by a French fishing vessel. It was relaid the next year and connections to Ireland and the Low Countries soon followed. Getting a cable across the Atlantic Ocean proved much more difficult. The Atlantic Telegraph Company , formed in London in 1856, had several failed attempts. A cable laid in 1858 worked poorly for
1079-440: A single-needle telegraph was adapted to indicate just two messages: "Line Clear" and "Line Blocked". The signaller would adjust his line-side signals accordingly. As first implemented in 1844 each station had as many needles as there were stations on the line, giving a complete picture of the traffic. As lines expanded, a sequence of pairs of single-needle instruments were adopted, one pair for each block in each direction. Wigwag
1162-663: A substantial distance was by Ronalds in 1816 using an electrostatic generator . Ronalds offered his invention to the British Admiralty , but it was rejected as unnecessary, the existing optical telegraph connecting the Admiralty in London to their main fleet base in Portsmouth being deemed adequate for their purposes. As late as 1844, after the electrical telegraph had come into use, the Admiralty's optical telegraph
1245-418: A system for mass distributing information on current price of publicly listed companies. In a punched-tape system, the message is first typed onto punched tape using the code of the telegraph system—Morse code for instance. It is then, either immediately or at some later time, run through a transmission machine which sends the message to the telegraph network. Multiple messages can be sequentially recorded on
1328-503: A system of communication that would allow the central government to receive intelligence and to transmit orders in the shortest possible time. On 2 March 1791, at 11 am, they sent the message "si vous réussissez, vous serez bientôt couverts de gloire" (If you succeed, you will soon bask in glory) between Brulon and Parce, a distance of 16 kilometres (10 mi). The first means used a combination of black and white panels, clocks, telescopes, and codebooks to send their message. In 1792, Claude
1411-534: A telefax machine. In 1855, an Italian priest, Giovanni Caselli , also created an electric telegraph that could transmit images. Caselli called his invention " Pantelegraph ". Pantelegraph was successfully tested and approved for a telegraph line between Paris and Lyon . In 1881, English inventor Shelford Bidwell constructed the scanning phototelegraph that was the first telefax machine to scan any two-dimensional original, not requiring manual plotting or drawing. Around 1900, German physicist Arthur Korn invented
1494-466: A telegraph between St Petersburg and Kronstadt , but it was never completed. The first operative electric telegraph ( Gauss and Weber , 1833) connected Göttingen Observatory to the Institute of Physics about 1 km away during experimental investigations of the geomagnetic field. The first commercial telegraph was by Cooke and Wheatstone following their English patent of 10 June 1837. It
1577-608: Is Selina Hayat Ivy . Prior to this, she was the mayor of Narayanganj Municipality. According to the 2022 Census of Bangladesh , present-day Narayanganj City Corporation had 255,468 households and a population of 967,951. The average household size was 3.74. Narayanganj had a literacy rate (age 7 and over) of 83.66%, compared to the national average of 74.80%, and a sex ratio of 99.85. Narayanganj has four railway stations named Pagla Halt railway station , Fatulla railway station , Chashara railway station and Narayanganj railway station . From Dhaka anyone can use three roads to enter
1660-465: Is a form of flag signalling using a single flag. Unlike most forms of flag signalling, which are used over relatively short distances, wigwag is designed to maximise the distance covered—up to 32 km (20 mi) in some cases. Wigwag achieved this by using a large flag—a single flag can be held with both hands unlike flag semaphore which has a flag in each hand—and using motions rather than positions as its symbols since motions are more easily seen. It
1743-554: Is a method of telegraphy, whereas pigeon post is not. Ancient signalling systems, although sometimes quite extensive and sophisticated as in China, were generally not capable of transmitting arbitrary text messages. Possible messages were fixed and predetermined, so such systems are thus not true telegraphs. The earliest true telegraph put into widespread use was the Chappe telegraph , an optical telegraph invented by Claude Chappe in
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#17328019671701826-519: Is a telegraph consisting of a line of stations in towers or natural high points which signal to each other by means of shutters or paddles. Signalling by means of indicator pointers was called semaphore . Early proposals for an optical telegraph system were made to the Royal Society by Robert Hooke in 1684 and were first implemented on an experimental level by Sir Richard Lovell Edgeworth in 1767. The first successful optical telegraph network
1909-458: Is a telegraph machine that can send messages from a typewriter-like keyboard and print incoming messages in readable text with no need for the operators to be trained in the telegraph code used on the line. It developed from various earlier printing telegraphs and resulted in improved transmission speeds. The Morse telegraph (1837) was originally conceived as a system marking indentations on paper tape. A chemical telegraph making blue marks improved
1992-447: Is that it permits duplex communication. The Wheatstone tape reader was capable of a speed of 400 words per minute. A worldwide communication network meant that telegraph cables would have to be laid across oceans. On land cables could be run uninsulated suspended from poles. Underwater, a good insulator that was both flexible and capable of resisting the ingress of seawater was required. A solution presented itself with gutta-percha ,
2075-518: Is the 6th largest city in Bangladesh. It is also a center of business and industry, especially the jute trade and processing plants, and the textile sector of the country. It is nicknamed the Dundee of Bangladesh, due to the presence of its many jute mills. (Dundee was the first industrialised 'Juteopolis' in the world. ) The city got its name from Bicon Lal Pandey, a Hindu religious leader who
2158-645: The Bildtelegraph widespread in continental Europe especially since a widely noticed transmission of a wanted-person photograph from Paris to London in 1908 used until the wider distribution of the radiofax. Its main competitors were the Bélinographe by Édouard Belin first, then since the 1930s, the Hellschreiber , invented in 1929 by German inventor Rudolf Hell , a pioneer in mechanical image scanning and transmission. The late 1880s through to
2241-660: The English Channel (1899), from shore to ship (1899) and finally across the Atlantic (1901). A study of these demonstrations of radio, with scientists trying to work out how a phenomenon predicted to have a short range could transmit "over the horizon", led to the discovery of a radio reflecting layer in the Earth's atmosphere in 1902, later called the ionosphere . Radiotelegraphy proved effective for rescue work in sea disasters by enabling effective communication between ships and from ship to shore. In 1904, Marconi began
2324-508: The First Macedonian War . Nothing else that could be described as a true telegraph existed until the 17th century. Possibly the first alphabetic telegraph code in the modern era is due to Franz Kessler who published his work in 1616. Kessler used a lamp placed inside a barrel with a moveable shutter operated by the signaller. The signals were observed at a distance with the newly invented telescope. An optical telegraph
2407-532: The London and Birmingham Railway line's chief engineer. The messages were for the operation of the rope-haulage system for pulling trains up the 1 in 77 bank. The world's first permanent railway telegraph was completed in July 1839 between London Paddington and West Drayton on the Great Western Railway with an electric telegraph using a four-needle system. The concept of a signalling "block" system
2490-530: The Tang dynasty (618–907) a message could be sent 1,100 kilometres (700 mi) in 24 hours. The Ming dynasty (1368–1644) added artillery to the possible signals. While the signalling was complex (for instance, different-coloured flags could be used to indicate enemy strength), only predetermined messages could be sent. The Chinese signalling system extended well beyond the Great Wall. Signal towers away from
2573-471: 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 . 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
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2656-530: The 1890s saw the discovery and then development of a newly understood phenomenon into a form of wireless telegraphy , called Hertzian wave wireless telegraphy, radiotelegraphy, or (later) simply " radio ". Between 1886 and 1888, Heinrich Rudolf Hertz published the results of his experiments where he was able to transmit electromagnetic waves (radio waves) through the air, proving James Clerk Maxwell 's 1873 theory of electromagnetic radiation . Many scientists and inventors experimented with this new phenomenon but
2739-534: The British government followed—by March 1897, Marconi had transmitted Morse code signals over a distance of about 6 km ( 3 + 1 ⁄ 2 mi) across Salisbury Plain . On 13 May 1897, Marconi, assisted by George Kemp, a Cardiff Post Office engineer, transmitted the first wireless signals over water to Lavernock (near Penarth in Wales) from Flat Holm . His star rising, he was soon sending signals across
2822-466: The Morse system connected Baltimore to Washington , and by 1861 the west coast of the continent was connected to the east coast. The Cooke and Wheatstone telegraph , in a series of improvements, also ended up with a one-wire system, but still using their own code and needle displays . The electric telegraph quickly became a means of more general communication. The Morse system was officially adopted as
2905-681: The United States by Samuel Morse . The electric telegraph was slower to develop in France due to the established optical telegraph system, but an electrical telegraph was put into use with a code compatible with the Chappe optical telegraph. The Morse system was adopted as the international standard in 1865, using a modified Morse code developed in Germany in 1848. The heliograph is a telegraph system using reflected sunlight for signalling. It
2988-512: The aggressors coming up the Shitalakshya River . This is a unique feature of the river forts built by Mughal Empire. The platform is surrounded by two circular structures of which the diameter of the inner one is 15.70 metres and the diameter of the outer one is 19.35 metres. The structure is 6.09 metres in height and surrounded by walls. The fort is quadrangular in plan, measuring 86.56 by 57.0 metres. There are octagonal bastions on
3071-451: The bottom. Several wide and narrow loopholes allowed guns and light cannons to fire shells at the pirates. The other one is a raised outwork on the western face to defend the fort from the attack of the pirates. The most significant structure of the fort is the massive artillery platform. One of the spherical artillery platforms has a stairway, which leads up to the artillery platform. Cannons with bigger calibre were placed on there, aiming at
3154-401: The city: Dhaka–Narayanganj old road , Dhaka–Narayanganj link road and Narayanganj–Demra road . The BRTC AC Bus gives bus transport service from Narayanganj to Dhaka. Telegraph Telegraphy is the long-distance transmission of messages where the sender uses symbolic codes, known to the recipient, rather than a physical exchange of an object bearing the message. Thus flag semaphore
3237-438: The consensus was that these new waves (similar to light) would be just as short range as light, and, therefore, useless for long range communication. At the end of 1894, the young Italian inventor Guglielmo Marconi began working on the idea of building a commercial wireless telegraphy system based on the use of Hertzian waves (radio waves), a line of inquiry that he noted other inventors did not seem to be pursuing. Building on
3320-411: The coordinates of the letter of the alphabet being transmitted. The number of said torches held up signalled the grid square that contained the letter. There is no definite record of the system ever being used, but there are several passages in ancient texts that some think are suggestive. Holzmann and Pehrson, for instance, suggest that Livy is describing its use by Philip V of Macedon in 207 BC during
3403-608: The defeat of Daud Khan Karrani by the Mughal General Munim Khan . Mughals exercised a progressive rule in Bengal and were determined to protect their subjects from external forces. Mir Jumla II was appointed as the Subahdar or governor of the then Bengal province in 1660 AD. He was aware of the pirates who ran a campaign of terror in the important cities of Bengal. In a quest to protect the capital Dhaka from
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3486-537: The erroneous belief that there was an electrified atmospheric stratum accessible at low altitude. They thought atmosphere current, connected with a return path using "Earth currents" would allow for wireless telegraphy as well as supply power for the telegraph, doing away with artificial batteries. A more practical demonstration of wireless transmission via conduction came in Amos Dolbear 's 1879 magneto electric telephone that used ground conduction to transmit over
3569-567: The fight against Geronimo and other Apache bands in the Apache Wars . Miles had previously set up the first heliograph line in the US between Fort Keogh and Fort Custer in Montana . He used the heliograph to fill in vast, thinly populated areas that were not covered by the electric telegraph. Twenty-six stations covered an area 320 by 480 km (200 by 300 mi). In a test of the system,
3652-623: The first commercial service to transmit nightly news summaries to subscribing ships, which could incorporate them into their on-board newspapers. A regular transatlantic radio-telegraph service was finally begun on 17 October 1907. Notably, Marconi's apparatus was used to help rescue efforts after the sinking of RMS Titanic . Britain's postmaster-general summed up, referring to the Titanic disaster, "Those who have been saved, have been saved through one man, Mr. Marconi...and his marvellous invention." The successful development of radiotelegraphy
3735-433: The four corners of the fort. The corner bastions on both sides of the western wing are wider than those of the eastern wing, which are 4.26 metres, while the two on the western wing are 6.85 metres in width. The only gate of the fort is on the north. The arched entrance is placed within a rectangular frame. The gateway is higher than the average height of the walls of fort and decorated with several groomed panels. There are
3818-651: The ground without any wires connecting the stations. Other attempts were made to send the electric current through bodies of water, to span rivers, for example. Prominent experimenters along these lines included Samuel F. B. Morse in the United States and James Bowman Lindsay in Great Britain, who in August 1854, was able to demonstrate transmission across a mill dam at a distance of 500 yards (457 metres). US inventors William Henry Ward (1871) and Mahlon Loomis (1872) developed electrical conduction systems based on
3901-419: The ideas of previous scientists and inventors Marconi re-engineered their apparatus by trial and error attempting to build a radio-based wireless telegraphic system that would function the same as wired telegraphy. He would work on the system through 1895 in his lab and then in field tests making improvements to extend its range. After many breakthroughs, including applying the wired telegraphy concept of grounding
3984-561: The largest ship of its day, designed by Isambard Kingdom Brunel . An overland telegraph from Britain to India was first connected in 1866 but was unreliable so a submarine telegraph cable was connected in 1870. Several telegraph companies were combined to form the Eastern Telegraph Company in 1872. Australia was first linked to the rest of the world in October 1872 by a submarine telegraph cable at Darwin . From
4067-594: The late 18th century. The system was used extensively in France, and European nations occupied by France, during the Napoleonic era . The electric telegraph started to replace the optical telegraph in the mid-19th century. It was first taken up in Britain in the form of the Cooke and Wheatstone telegraph , initially used mostly as an aid to railway signalling . This was quickly followed by a different system developed in
4150-421: The line at his own expense and agreed that the railway could have free use of it in exchange for the right to open it up to the public. Most of the early electrical systems required multiple wires (Ronalds' system was an exception), but the system developed in the United States by Morse and Vail was a single-wire system. This was the system that first used the soon-to-become-ubiquitous Morse code . By 1844,
4233-526: The method used for transmission. Passing messages by signalling over distance is an ancient practice. One of the oldest examples is the signal towers of the Great Wall of China . In 400 BC , signals could be sent by beacon fires or drum beats . By 200 BC complex flag signalling had developed, and by the Han dynasty (200 BC – 220 AD) signallers had a choice of lights, flags, or gunshots to send signals. By
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#17328019671704316-569: The modern International Morse code) to aid differentiating from the morse dot. Use of the heliograph declined from 1915 onwards, but remained in service in Britain and British Commonwealth countries for some time. Australian forces used the heliograph as late as 1942 in the Western Desert Campaign of World War II . Some form of heliograph was used by the mujahideen in the Soviet–Afghan War (1979–1989). A teleprinter
4399-507: The pirates, Mir Jumla II decided to build three river forts around Dhaka, including Sonakanda Fort. Though archaeologists cannot trace any evidence on its date of establishment, according to historians the construction of the fort started between 1660 and 1663 AD. The fort combines thick walls, a massive artillery platform and a gateway to the north. The fort has two main parts. One is a fortified defensive wall of gigantic dimensions. The defensive walls are 3.05 metres in height and thicker at
4482-399: The possible messages. One of the few for which details are known is a system invented by Aeneas Tacticus (4th century BC). Tacticus's system had water filled pots at the two signal stations which were drained in synchronisation. Annotation on a floating scale indicated which message was being sent or received. Signals sent by means of torches indicated when to start and stop draining to keep
4565-419: The same run of tape. The advantage of doing this is that messages can be sent at a steady, fast rate making maximum use of the available telegraph lines. The economic advantage of doing this is greatest on long, busy routes where the cost of the extra step of preparing the tape is outweighed by the cost of providing more telegraph lines. The first machine to use punched tape was Bain's teleprinter (Bain, 1843), but
4648-403: The speed of recording ( Bain , 1846), but was delayed by a patent challenge from Morse. The first true printing telegraph (that is printing in plain text) used a spinning wheel of types in the manner of a daisy wheel printer ( House , 1846, improved by Hughes , 1855). The system was adopted by Western Union . Early teleprinters used the Baudot code , a five-bit sequential binary code. This
4731-579: The standard for continental European telegraphy in 1851 with a revised code, which later became the basis of International Morse Code . However, Great Britain and the British Empire continued to use the Cooke and Wheatstone system, in some places as late as the 1930s. Likewise, the United States continued to use American Morse code internally, requiring translation operators skilled in both codes for international messages. Railway signal telegraphy
4814-462: The synchronisation. None of the signalling systems discussed above are true telegraphs in the sense of a system that can transmit arbitrary messages over arbitrary distances. Lines of signalling relay stations can send messages to any required distance, but all these systems are limited to one extent or another in the range of messages that they can send. A system like flag semaphore , with an alphabetic code, can certainly send any given message, but
4897-559: The system is designed for short-range communication between two persons. An engine order telegraph , used to send instructions from the bridge of a ship to the engine room, fails to meet both criteria; it has a limited distance and very simple message set. There was only one ancient signalling system described that does meet these criteria. That was a system using the Polybius square to encode an alphabet. Polybius (2nd century BC) suggested using two successive groups of torches to identify
4980-619: The system saw only limited use. Later versions of Bain's system achieved speeds up to 1000 words per minute, far faster than a human operator could achieve. The first widely used system (Wheatstone, 1858) was first put into service with the British General Post Office in 1867. A novel feature of the Wheatstone system was the use of bipolar encoding . That is, both positive and negative polarity voltages were used. Bipolar encoding has several advantages, one of which
5063-405: The telegraph into decline from 1920 onwards. The few remaining telegraph applications were largely taken over by alternatives on the internet towards the end of the 20th century. The word telegraph (from Ancient Greek : τῆλε ( têle ) 'at a distance' and γράφειν ( gráphein ) 'to write') was coined by the French inventor of the semaphore telegraph , Claude Chappe , who also coined
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#17328019671705146-537: The transmitter and receiver, Marconi was able, by early 1896, to transmit radio far beyond the short ranges that had been predicted. Having failed to interest the Italian government, the 22-year-old inventor brought his telegraphy system to Britain in 1896 and met William Preece , a Welshman, who was a major figure in the field and Chief Engineer of the General Post Office . A series of demonstrations for
5229-445: The two stations to form a complete electrical circuit or "loop". In 1837, however, Carl August von Steinheil of Munich , Germany , found that by connecting one leg of the apparatus at each station to metal plates buried in the ground, he could eliminate one wire and use a single wire for telegraphic communication. This led to speculation that it might be possible to eliminate both wires and therefore transmit telegraph signals through
5312-546: The wall were used to give early warning of an attack. Others were built even further out as part of the protection of trade routes, especially the Silk Road . Signal fires were widely used in Europe and elsewhere for military purposes. The Roman army made frequent use of them, as did their enemies, and the remains of some of the stations still exist. Few details have been recorded of European/Mediterranean signalling systems and
5395-463: The word semaphore . A telegraph is a device for transmitting and receiving messages over long distances, i.e., for telegraphy. The word telegraph alone generally refers to an electrical telegraph . Wireless telegraphy is transmission of messages over radio with telegraphic codes. Contrary to the extensive definition used by Chappe, Morse argued that the term telegraph can strictly be applied only to systems that transmit and record messages at
5478-485: Was a telegraph code developed for use on the French telegraph using a five-key keyboard ( Baudot , 1874). Teleprinters generated the same code from a full alphanumeric keyboard. A feature of the Baudot code, and subsequent telegraph codes, was that, unlike Morse code, every character has a code of the same length making it more machine friendly. The Baudot code was used on the earliest ticker tape machines ( Calahan , 1867),
5561-546: Was also known as Benur Thakur or 'Lakshmi Narayan Thakur'. He leased the area from the British East India Company in 1766 following the Battle of Plassey . He donated the markets and the land on the banks of the river as Devottor or 'Given to God' property, bequeathed for maintenance expenses for the worship of the god Narayan . A post office was set up in 1866, and Dhaka-Narayanganj telegraph service
5644-474: Was appointed Ingénieur-Télégraphiste and charged with establishing a line of stations between Paris and Lille , a distance of 230 kilometres (140 mi). It was used to carry dispatches for the war between France and Austria. In 1794, it brought news of a French capture of Condé-sur-l'Escaut from the Austrians less than an hour after it occurred. A decision to replace the system with an electric telegraph
5727-414: Was demonstrated on the London and Birmingham Railway in July of the same year. In July 1839, a five-needle, five-wire system was installed to provide signalling over a record distance of 21 km on a section of the Great Western Railway between London Paddington station and West Drayton. However, in trying to get railway companies to take up his telegraph more widely for railway signalling , Cooke
5810-421: Was developed in Britain from the 1840s onward. It was used to manage railway traffic and to prevent accidents as part of the railway signalling system. On 12 June 1837 Cooke and Wheatstone were awarded a patent for an electric telegraph. This was demonstrated between Euston railway station —where Wheatstone was located—and the engine house at Camden Town—where Cooke was stationed, together with Robert Stephenson ,
5893-552: Was invented by Claude Chappe and operated in France from 1793. The two most extensive systems were Chappe's in France, with branches into neighbouring countries, and the system of Abraham Niclas Edelcrantz in Sweden. During 1790–1795, at the height of the French Revolution , France needed a swift and reliable communication system to thwart the war efforts of its enemies. In 1790, the Chappe brothers set about devising
5976-536: Was invented by US Army surgeon Albert J. Myer in the 1850s who later became the first head of the Signal Corps . Wigwag was used extensively during the American Civil War where it filled a gap left by the electrical telegraph. Although the electrical telegraph had been in use for more than a decade, the network did not yet reach everywhere and portable, ruggedized equipment suitable for military use
6059-403: Was known as a telegram. A cablegram was a message sent by a submarine telegraph cable, often shortened to "cable" or "wire". The suffix -gram is derived from ancient Greek: γραμμα ( gramma ), meaning something written, i.e. telegram means something written at a distance and cablegram means something written via a cable, whereas telegraph implies the process of writing at a distance. Later,
6142-782: Was made in 1846, but it took a decade before it was fully taken out of service. The fall of Sevastopol was reported by Chappe telegraph in 1855. The Prussian system was put into effect in the 1830s. However, they were highly dependent on good weather and daylight to work and even then could accommodate only about two words per minute. The last commercial semaphore link ceased operation in Sweden in 1880. As of 1895, France still operated coastal commercial semaphore telegraph stations, for ship-to-shore communication. The early ideas for an electric telegraph included in 1753 using electrostatic deflections of pith balls, proposals for electrochemical bubbles in acid by Campillo in 1804 and von Sömmering in 1809. The first experimental system over
6225-575: Was mainly used in areas where the electrical telegraph had not been established and generally used the same code. The most extensive heliograph network established was in Arizona and New Mexico during the Apache Wars . The heliograph was standard military equipment as late as World War II . Wireless telegraphy developed in the early 20th century became important for maritime use, and was a competitor to electrical telegraphy using submarine telegraph cables in international communications. Telegrams became
6308-400: Was not immediately available. Permanent or semi-permanent stations were established during the war, some of them towers of enormous height and the system was extensive enough to be described as a communications network. A heliograph is a telegraph that transmits messages by flashing sunlight with a mirror, usually using Morse code. The idea for a telegraph of this type was first proposed as
6391-455: Was preceded by a 50-year history of ingenious but ultimately unsuccessful experiments by inventors to achieve wireless telegraphy by other means. Several wireless electrical signaling schemes based on the (sometimes erroneous) idea that electric currents could be conducted long-range through water, ground, and air were investigated for telegraphy before practical radio systems became available. The original telegraph lines used two wires between
6474-433: Was proposed by Cooke in 1842. Railway signal telegraphy did not change in essence from Cooke's initial concept for more than a century. In this system each line of railway was divided into sections or blocks of varying length. Entry to and exit from the block was to be authorised by electric telegraph and signalled by the line-side semaphore signals, so that only a single train could occupy the rails. In Cooke's original system,
6557-549: Was rejected several times in favour of the more familiar, but shorter range, steam-powered pneumatic signalling. Even when his telegraph was taken up, it was considered experimental and the company backed out of a plan to finance extending the telegraph line out to Slough . However, this led to a breakthrough for the electric telegraph, as up to this point the Great Western had insisted on exclusive use and refused Cooke permission to open public telegraph offices. Cooke extended
6640-615: Was started in 1877. The Bank of Bengal introduced the first telephone service in 1882. The Narayanganj Municipality was incorporated on 8 September 1876. The first hospital in the area of Narayanganj Victoria Hospital was established in 1885 by the Municipality with financial contributions from Harakanta Banerjee. Narayanganj City Corporation was established on 5 May 2011, unifying three former municipalities: Narayanganj Municipality, Siddhirganj Municipality , and Kadam Rasul Municipality. The mayor of Narayanganj City Corporation (NCC)
6723-496: Was still 42.7 percent. During World War I , Britain's telegraph communications were almost completely uninterrupted while it was able to quickly cut Germany's cables worldwide. In 1843, Scottish inventor Alexander Bain invented a device that could be considered the first facsimile machine . He called his invention a "recording telegraph". Bain's telegraph was able to transmit images by electrical wires. Frederick Bakewell made several improvements on Bain's design and demonstrated
6806-404: Was still used, although it was accepted that poor weather ruled it out on many days of the year. France had an extensive optical telegraph system dating from Napoleonic times and was even slower to take up electrical systems. Eventually, electrostatic telegraphs were abandoned in favour of electromagnetic systems. An early experimental system ( Schilling , 1832) led to a proposal to establish
6889-480: Was used by British military in many colonial wars, including the Anglo-Zulu War (1879). At some point, a morse key was added to the apparatus to give the operator the same degree of control as in the electric telegraph. Another type of heliograph was the heliostat or heliotrope fitted with a Colomb shutter. The heliostat was essentially a surveying instrument with a fixed mirror and so could not transmit
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