Tuesday, November 5, 2019
The History of the Electric Telegraph and Telegraphy
The History of the Electric Telegraph and Telegraphy The electric telegraph is a now outdated communication system that transmitted electric signals over wires from location to location and then translated into a message. The non-electric telegraph was invented by Claude Chappe in 1794. His system was visual and used semaphore, a flag-based alphabet, and depended on a line of sight for communication. The optical telegraph was later replaced by the electric telegraph, which is the focus of this article. In 1809, a crude telegraph was invented in Bavaria by Samuel Soemmering. He used 35 wires with gold electrodes in water.à At the receiving end,à the message was read 2,000 feet awayà by the amount of gas produced by electrolysis. In 1828, the first telegraph in the USA was invented by Harrison Dyar, who sent electrical sparks through chemically treated paper tape to burn dots and dashes. Electromagnet In 1825, British inventor William Sturgeon (1783-1850) introduced an invention that laid the foundationà for a large scale revolution in electronic communications: the electromagnet. Sturgeon demonstrated the power of the electromagnet by lifting nine pounds with a seven-ounce piece of iron wrapped with wires through which the current of a single cell battery was sent. However, the true power of the electromagnet comes from its role in the creation of countless inventions to come. The Emergence of Telegraph Systems In 1830, an American namedà Joseph Henry (1797-1878) demonstrated the potential of William Sturgeons electromagnet for long distance communication by sending an electronic current over one mile of wire to activate an electromagnet, causing a bell to strike. In 1837, British physicistsà William Cooke and Charles Wheatstone patented the Cooke and Wheatstone telegraph using the same principle of electromagnetism. However, it was Samuel Morse (1791-1872) who successfully exploited the electromagnet and bettered Henrys invention. Morse started by making sketches of a magnetized magnet based on Henrys work. Eventually, he invented a telegraph system that was a practical and commercial success. Samuel Morse While teaching arts and design at New York University in 1835, Morse proved that signals could be transmitted by wire. He used pulses of current to deflect an electromagnet, which moved a marker to produce written codes on a strip of paper. Thisà led to the invention of Morse Code. The following year, the device was modified to emboss the paper with dots and dashes. He gave a public demonstration in 1838, but it wasnt until five years later that Congress, reflecting public apathy, awarded himà $30,000 to construct an experimental telegraph line from Washington to Baltimore, a distance of 40 miles. Six years later, members of Congress witnessed the transmission of messages over part of the telegraph line. Before the line had reached Baltimore, the Whig party held its national convention thereà and nominated Henry Clayà onà May 1, 1844. The news was hand-carried to Annapolis Junction, between Washington and Baltimore, where Morses partner Alfred Vail wired it to the capitol. This was the first news dispatched by electric telegraph. What Hath God Wrought? The messageà What hath God wrought? sent by Morse Code from the old Supreme Court chamber in the United States capitol to his partner in Baltimore officially opened the completed line on May 24, 1844. Morse allowed Annie Ellsworth, the young daughter of a friend, to choose the words of the message and she selected a verse from Numbers XXIII, 23: What hath God wrought? to be recorded onto paper tape. Morses early system produced a paper copy with raised dots and dashes, which were translated later by an operator. The Telegraph Spreads Samuel Morse and his associates obtained private funds to extend their line to Philadelphia and New York. Small telegraph companies, meanwhile began functioning in the East, South, and Midwest. Dispatching trains by telegraph started in 1851, the same year Western Union began business. Western Union built its first transcontinental telegraph line in 1861, mainly along railroad rights-of-way. In 1881, the Postal Telegraph System entered the field for economic reasons and later merged with Western Union in 1943. The original Morse telegraph printed code on tape. However, in the United States, the operation developed into a process in which messages were sent by key and received by ear. A trained Morse operator could transmit 40 to 50 words per minute. Automatic transmission, introduced in 1914, handled more than twice that number. In 1900, Canadian Fredrick Creed invented the Creed Telegraph System,à a way to convert Morse code to text. Multiplex Telegraph, Teleprinters, Other Advancements In 1913, Western Union developed multiplexing, which made it possible to transmit eight messages simultaneously over a single wire (four in each direction). Teleprinter machines came into use aroundà 1925 and in 1936 Varioplex was introduced. This enabled a single wire to carry 72 transmissions at the same time (36 in each direction). Two years later, Western Union introduced the first of its automatic facsimile devices. In 1959, Western Union inaugurated TELEX, which enabled subscribers to the teleprinter service to dial each other directly. Telephone Rivals the Telegraph Until 1877, all rapid long-distance communication depended upon the telegraph. That year, a rival technology developed that would again change the face of communication:à the telephone. By 1879, patent litigation between Western Union and the infant telephone systemà ended in an agreement that largely separated the two services. While Samuel Morse is best known as the inventor of the telegraph, he is also esteemed for his contributions to American portraiture. His painting is characterized by delicate technique and vigorous honesty and insight into the character of his subjects.
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