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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 costs since it halves the amount of wire that is required, with a corresponding saving on the labour required to string it. The benefits of doing this were not immediately noticed by telegraph pioneers, but it rapidly became the norm after the first earth-return telegraph was put into service by Carl August von Steinheil in 1838. Earth-return telegraph began to have problems towards the end of the 19th century due to the introduction of electric trams. These seriously disturbed earth-return operation and some circuits were returned to the old metal-conductor return system. At the same time, the rise of telephony, which was even more intolerant to the interference on earth-return systems, started to displace electrical telegraphy altogether, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyrillic Alphabet
, bg, кирилица , mk, кирилица , russian: кириллица , sr, ћирилица, uk, кирилиця , fam1 = Egyptian hieroglyphs , fam2 = Proto-Sinaitic , fam3 = Phoenician , fam4 = Greek script augmented by Glagolitic , sisters = , children = Old Permic script , unicode = , iso15924 = Cyrl , iso15924 note = Cyrs ( Old Church Slavonic variant) , sample = Romanian Traditional Cyrillic - Lord's Prayer text.png , caption = 1780s Romanian text (Lord's Prayer), written with the Cyrillic script The Cyrillic script ( ), Slavonic script or the Slavic script, is a writing system used for various languages across Eurasia. It is the designated national script in various Slavic, Turkic, Mongolic, Uralic, Caucasian and Iranic-speaking countries in Southeastern Europe, Eastern Europe, the Caucasus, Central Asia, North Asia, and East Asia. , around 250 million people in Eurasia use Cyrillic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Henry Winkler
John is a common English name and surname: * John (given name) * John (surname) John may also refer to: New Testament Works * Gospel of John, a title often shortened to John * First Epistle of John, often shortened to 1 John * Second Epistle of John, often shortened to 2 John * Third Epistle of John, often shortened to 3 John People * John the Baptist (died c. AD 30), regarded as a prophet and the forerunner of Jesus Christ * John the Apostle (lived c. AD 30), one of the twelve apostles of Jesus * John the Evangelist, assigned author of the Fourth Gospel, once identified with the Apostle * John of Patmos, also known as John the Divine or John the Revelator, the author of the Book of Revelation, once identified with the Apostle * John the Presbyter, a figure either identified with or distinguished from the Apostle, the Evangelist and John of Patmos Other people with the given name Religious figures * John, father of Andrew the Apostle and Saint Peter * Pope Joh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shooter's Hill
Shooter's Hill (or Shooters Hill) is a district in South East London within the Royal Borough of Greenwich. It borders the London Borough of Bexley. It lies north of Eltham and south of Woolwich. With a height of , it is the highest point in the Borough of Greenwich and one of the highest points in Greater London. Shooter's Hill also gives its name to the A road which passes through east to west and is part of the A207 road, the A2 road, and also Watling Street. Geography It reputedly takes its name from the practice of archery there during the Middle Ages, although the name is also commonly linked to its reputation as a haunt for highwaymen and was infamous for its gibbets of executed criminals. In the Second World War it was the site of an array of anti-aircraft guns which protected London. As part of 'London Stop Line Central' it was a last line of defence from a German land invasion, that was assumed would follow Watling Street from Dover. A number of devices were under t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
William Watson (scientist)
Sir William Watson, FRS (3 April 1715 – 10 May 1787) was a British physician and scientist who was born and died in London. His early work was in botany, and he helped to introduce the work of Carolus Linnaeus into England. He became a Fellow of the Royal Society in 1741 and vice president in 1772. He was knighted in 1786. In 1746, he showed that the capacity of the Leyden jar could be increased by coating it inside and out with lead foil. In the same year, he proposed that the two types of electricity—vitreous and resinous—posited by DuFay were actually a surplus (a positive charge) and a deficiency (a negative charge) of a single fluid which he called ''electrical ether'', and that the quantity of electrical charge was conserved. He acknowledged that the same theory had been independently developed at the same time by Benjamin Franklin—the two men later became allies in both scientific and political matters. He also suggested that electricity is more ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
William Watson
William, Willie, Bill or Billy Watson may refer to: Entertainment * William Watson (songwriter) (1794–1840), English concert hall singer and songwriter * William Watson (poet) (1858–1935), English poet * Billy Watson (actor) (1923–2022), American actor * William Watson (writer) (1930–2005), also known as Bill Watson, Scottish writer * William C. Watson (1938–1997), American actor * Willie Watson (musician) (born 1979), American folk musician Military * William H. Watson (1815–1846), Mexican–American War soldier from Maryland, U.S. * William Watson (sergeant) (1826–1906), in the Confederate States Army * William Watson (surgeon) (1837–1879), in Pennsylvania Volunteers during the American Civil War * William Thornton Watson (1887–1961), New Zealand officer in the Australian Imperial Force * William E. Watson, military historian Politics * William Watson (16th century MP), MP for the City of York * William Henry Watson (1796–1860), British politician an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 numerous applications, such as the solenoid (a term coined by him) and the electrical telegraph. As an autodidact, Ampère was a member of the French Academy of Sciences and professor at the École polytechnique and the Collège de France. The SI unit of measurement of electric current, the ampere, is named after him. His name is also one of the 72 names inscribed on the Eiffel Tower. Early life André-Marie Ampère was born on 20 January 1775 to Jean-Jacques Ampère, a prosperous businessman, and Jeanne Antoinette Desutières-Sarcey Ampère, during the height of the French Enlightenment. He spent his childhood and adolescence at the family property at Poleymieux-au-Mont-d'Or near Lyon. Jean-Jacques Ampère, a successful merchant, was an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
William Ritchie (physicist)
William Ritchie (1790?–1837) was a Scottish physicist. He was noted as an ingenious experimentalist. Life Born about 1790, he was educated for the Church of Scotland, and was licensed to preach; but he abandoning the church for the teaching profession. He became rector of the Royal Academy of Tain, in Ross-shire. After saving a little money, he provided a substitute to perform his duties, and went to Paris. There he attended the lectures of Louis Jacques Thénard, Joseph Louis Gay-Lussac, and Jean-Baptiste Biot. He soon acquired skill in devising and performing experiments in natural philosophy. Ritchie's publications led to his appointment to the professorship of natural philosophy at the Royal Institution, where he delivered a course of probationary lectures in 1829. In 1832 he was appointed professor of natural philosophy in London University. Ritchie was subsequently engaged on experiments on the manufacture of glass for optical purposes, and a commission was appointed b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 and the nervous system, on the sensory organs, on the embryo and its malformations, on the structure of the lungs, etc., made him one of the most important German anatomists. Career Sömmerring was born in Thorn (Toruń), Royal Prussia (a province of the Crown of Poland) as the ninth child of the physician Johann Thomas Sömmerring. In 1774 he completed his education in Thorn and began to study medicine at the University of Göttingen. He visited Petrus Camper lecturing at the University in Franeker. He became a professor of anatomy at the Collegium Carolinum (housed in the Ottoneum, now a Natural History Museum) in Kassel and, beginning in 1784, at the University of Mainz. There he was for five years the dean of the medical faculty. Aft ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 system based on European telegraphs. He was a co-developer of Morse code and helped to develop the commercial use of telegraphy. Personal life Samuel F. B. Morse was born in Charlestown, Massachusetts, the first child of the pastor Jedidiah Morse (1761–1826), who was also a geographer, and his wife Elizabeth Ann Finley Breese (1766–1828). His father was a great preacher of the Calvinist faith and supporter of the Federalist Party. He thought it helped preserve Puritan traditions (strict observance of Sabbath, among other things), and believed in the Federalist support of an alliance with Britain and a strong central government. Morse strongly believed in education within a Federalist framework, alongside the instillation of Calvin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Numerical Digit
A numerical digit (often shortened to just digit) is a single symbol used alone (such as "2") or in combinations (such as "25"), to represent numbers in a positional numeral system. The name "digit" comes from the fact that the ten digits (Latin ''digiti'' meaning fingers) of the hands correspond to the ten symbols of the common base 10 numeral system, i.e. the decimal (ancient Latin adjective ''decem'' meaning ten) digits. For a given numeral system with an integer base, the number of different digits required is given by the absolute value of the base. For example, the decimal system (base 10) requires ten digits (0 through to 9), whereas the binary system (base 2) requires two digits (0 and 1). Overview In a basic digital system, a numeral is a sequence of digits, which may be of arbitrary length. Each position in the sequence has a place value, and each digit has a value. The value of the numeral is computed by multiplying each digit in the sequence by its ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
