Herman Hollerith

From Wikipedia, the free encyclopedia

416px-Hollerith

Herman Hollerith (February 29, 1860 – November 17, 1929) was an American inventor who developed an electromechanical punched card tabulator to assist in summarizing information and, later, accounting. He was the founder of the Tabulating Machine Company that was amalgamated (via stock acquisition) in 1911 with three other companies to form a fifth company, the Computing-Tabulating-Recording Company later renamed IBM. Hollerith is regarded as one of the seminal figures in the development of data processing. His invention of the punched card tabulating machine marks the beginning of the era of semiautomatic data processing systems, and his concept dominated that landscape for nearly a century.

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Personal life


Herman Hollerith was born the son of German immigrant Prof. Georg Hollerith from Großfischlingen (near Neustadt an der Weinstraße) in Buffalo, New York, where he spent his early childhood. He entered the City College of New York in 1875, graduated from the Columbia University School of Mines with an “Engineer of Mines” degree in 1879 at age 19, and in 1890 asked for (and was awarded) a Ph.D based on his development of the tabulating system. In 1882 Hollerith joined the Massachusetts Institute of Technology where he taught mechanical engineering and conducted his first experiments with punched cards. He eventually moved to Washington, D.C., living in Georgetown, with a home on 29th Street and a business building at 31st Street and the C&O Canal, where today there is a commemorative plaque installed by IBM. He died in Washington D.C. of a heart attack.

Electromechanical Tabulation of Data


At the urging of John Shaw Billings, Hollerith developed a mechanism using electrical connections to increment a counter, recording information. A key idea was that a datum could be recorded by the presence or absence of a hole at a specific location on a card. For example, if a specific hole location indicates marital status, then a hole there can indicate married while not having a hole indicates single. Hollerith determined that data in specified locations on a card, the now-familiar rows and columns, could be counted or sorted electromechanically. A description of this system, An Electric Tabulating System (1889), was submitted by Hollerith to Columbia University as his doctoral thesis, and is reprinted in Randell’s book. On January 8, 1889, Hollerith was issued U.S. Patent 395,782, claim 2 of which reads:

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Photo dated 1919.12.31 of census worker with Hollerith pantograph punch. The keyboard layout is for the US Census 1920 population card.

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Replica of Hollerith tabulating machine with sorting box, circa 1890. The “sorting box” was an adjunct to, and controlled by, the tabulator. The “sorter”, an independent machine, was a later development.

The herein-described method of compiling statistics, which consists in recording separate statistical items pertaining to the individual by holes or combinations of holes punched in sheets of electrically non-conducting material, and bearing a specific relation to each other and to a standard, and then counting or tallying such statistical items separately or in combination by means of mechanical counters operated by electro-magnets the circuits through which are controlled by the perforated sheets, substantially as and for the purpose set forth.

Inventions and Businesses


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Hollerith punched card

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Hollerith’s grave at Oak Hill Cemetery in Georgetown in Washington, D.C.

Hollerith had left teaching and begun working for the United States Census Bureau in the year he filed his first patent application. Titled “Art of Compiling Statistics”, it was filed on September 23, 1884; U.S. Patent 395,782 was granted on January 8, 1889.

Hollerith initially did business under his own name, as The Hollerith Electric Tabulating System, specializing in punched card data processing equipment. He provided tabulators and other machines under contract for the Census Office, which used them for the 1890 census. The net effect of the many changes from the 1880 census: the larger population, the data items to be collected, the Census Bureau headcount, the scheduled publications, and the use of Hollerith’s electromechanical tabulators, was to reduce the time required to process the census from eight years for the 1880 census to six years for the 1890 census.

In 1896 Hollerith founded the Tabulating Machine Company (in 1905 renamed The Tabulating Machine Company). Many major census bureaus around the world leased his equipment and purchased his cards, as did major insurance companies. Hollerith’s machines were used for censuses in England, Italy, Germany, Russia, Austria, Canada, France, Norway, Puerto Rico, Cuba, and the Philippines, and again in the 1900 census.

He invented the first automatic card-feed mechanism and the first keypunch. The 1890 Tabulator was hardwired to operate on 1890 Census cards. A control panel in his 1906 Type I Tabulator simplified rewiring for different jobs. The 1920s removable control panel supported prewiring and near instant job changing. These inventions were among the foundations of the data processing industry and Hollerith’s punched cards (later used for computer input/output) continued in use for almost a century.

In 1911 four corporations, including Hollerith’s firm, were amalgamated to form a fifth company, the Computing-Tabulating-Recording Company (CTR). Under the presidency of Thomas J. Watson, CTR was renamed International Business Machines Corporation (IBM) in 1924. By 1933 The Tabulating Machine Company name had disappeared as subsidiary companies were subsumed by IBM.

Death and Legacy


Hollerith is buried at Oak Hill Cemetery in the Georgetown neighborhood of Washington, D.C.

Hollerith cards were named after Herman Hollerith, as were Hollerith constants (a string constant declaration in some computer programming languages, sometimes called a Hollerith string).

His great-grandson, the Rt. Rev. Herman Hollerith IV is the Episcopal bishop of the Diocese of Southern Virginia, and another great-grandson, Randolph Marshall Hollerith, is an Episcopal priest and the dean of Washington National Cathedral in Washington D.C..

John Logie Baird

From Wikipedia, the free encyclopedia

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John Logie Baird FRSE (/ˈloʊɡi bɛərd/; 13 August 1888 – 14 June 1946) was a Scottish engineer, innovator, one of the inventors of the mechanical television, demonstrating the first working television system on 26 January 1926, and inventor of both the first publicly demonstrated colour television system, and the first purely electronic colour television picture tube.

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In 1928 the Baird Television Development Company achieved the first transatlantic television transmission. Baird’s early technological successes and his role in the practical introduction of broadcast television for home entertainment have earned him a prominent place in television’s history.

Baird was ranked number 44 in the BBC’s list of the 100 Greatest Britons following a UK-wide vote in 2002. In 2006, Baird was named as one of the 10 greatest Scottish scientists in history, having been listed in the National Library of Scotland’s ‘Scottish Science Hall of Fame’. In 2015 he was inducted into the Scottish Engineering Hall of Fame.

Early Years


Baird was born on 13 August 1888 in Helensburgh, Dunbartonshire, and was the youngest of four children of the Reverend John Baird, the Church of Scotland’s minister for the local St Bride’s Church and Jessie Morrison Inglis, the orphaned niece of a wealthy family of shipbuilders from Glasgow.

He was educated at Larchfield Academy (now part of Lomond School) in Helensburgh; the Glasgow and West of Scotland Technical College; and the University of Glasgow. While at college Baird undertook a series of engineering apprentice jobs as part of his course. The conditions in industrial Glasgow at the time helped form his socialist convictions but also contributed to his ill health. He became an agnostic, though this did not strain his relationship with his father. His degree course was interrupted by the First World War and he never returned to graduate.

At the beginning of 1915 he volunteered for service in the British Army but was classified as unfit for active duty. Unable to go to the Front, he took a job with the Clyde Valley Electrical Power Company, which was engaged in munitions work.

Television Experiments


The development of television was the result of work by many inventors. Among them, Baird was a prominent pioneer and made major advances in the field. Many historians credit Baird with being the first to produce a live, moving, greyscale television image from reflected light. Baird achieved this, where other inventors had failed, by obtaining a better photoelectric cell and improving the signal conditioning from the photocell and the video amplifier.

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John Logie Baird with his television apparatus, circa 1925

Between 1902 and 1907, Arthur Korn invented and built the first successful signal-conditioning circuits for image transmission. The circuits overcame the image-destroying lag effect that is part of selenium photocells. Korn’s compensation circuit allowed him to send still fax pictures by telephone or wireless between countries and even over oceans, while his circuit operated without benefit of electronic amplification. Korn’s success at transmitting halftone still images suggested that such compensation circuits might work in television. Baird was the direct beneficiary of Korn’s research and success.

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An early experimental television broadcast

In his first attempts to develop a working television system, Baird experimented with the Nipkow disk. Paul Gottlieb Nipkow had invented this scanning disc system in 1884. Television historian Albert Abramson calls Nipkow’s patent “the master television patent”. Nipkow’s work is important because Baird and many others chose to develop it into a broadcast medium.

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Baird in 1926 with his televisor equipment and dummies “James” and “Stooky Bill”

In early 1923, and in poor health, Baird moved to 21 Linton Crescent, Hastings, on the south coast of England. He later rented a workshop in the Queen’s Arcade in the town. Baird built what was to become the world’s first working television set using items including an old hatbox and a pair of scissors, some darning needles, a few bicycle light lenses, a used tea chest, and sealing wax and glue that he purchased. In February 1924, he demonstrated to the Radio Times that a semi-mechanical analogue television system was possible by transmitting moving silhouette images. In July of the same year, he received a 1000-volt electric shock, but survived with only a burnt hand, and as a result his landlord, Mr Tree, asked him to vacate the premises. Baird gave the first public demonstration of moving silhouette images by television at Selfridges department store in London in a three-week series of demonstrations beginning on 25 March 1925.

In his laboratory on 2 October 1925, Baird successfully transmitted the first television picture with a greyscale image: the head of a ventriloquist’s dummy nicknamed “Stooky Bill” in a 30-line vertically scanned image, at five pictures per second. Baird went downstairs and fetched an office worker, 20-year-old William Edward Taynton, to see what a human face would look like, and Taynton became the first person to be televised in a full tonal range. Looking for publicity, Baird visited the Daily Express newspaper to promote his invention. The news editor was terrified and he was quoted by one of his staff as saying: “For God’s sake, go down to reception and get rid of a lunatic who’s down there. He says he’s got a machine for seeing by wireless! Watch him — he may have a razor on him.”

First public demonstrations

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The first known photograph of a moving image produced by Baird’s “televisor”, as reported in The Times, 28 January 1926 (The subject is Baird’s business partner Oliver Hutchinson.)

On 26 January 1926, Baird repeated the transmission for members of the Royal Institution and a reporter from The Times in his laboratory at 22 Frith Street in the Soho district of London, where Bar Italia is now located. By this time, he had improved the scan rate to 12.5 pictures per second. It was the first demonstration of a television system that could broadcast live moving images with tone graduation.

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Blue plaque marking Baird’s first demonstration of television at 22 Frith Street, Westminster, W1, London

He demonstrated the world’s first colour transmission on 3 July 1928, using scanning discs at the transmitting and receiving ends with three spirals of apertures, each spiral with a filter of a different primary colour; and three light sources at the receiving end, with a commutator to alternate their illumination. The demonstration was of a young girl wearing different coloured hats. Noele Gordon went on to become a successful TV actress, famous for the soap opera Crossroads. That same year he also demonstrated stereoscopic television.

Broadcasting

In 1927, Baird transmitted a long-distance television signal over 438 miles (705 km) of telephone line between London and Glasgow; Baird transmitted the world’s first long-distance television pictures to the Central Hotel at Glasgow Central Station.This transmission was Baird’s response to a 225-mile, long-distance telecast between stations of AT&T Bell Labs. The Bell stations were in New York and Washington, DC. The earlier telecast took place in April 1927, a month before Baird’s demonstration.

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Baird demonstrating his mechanical television system in New York, 1931

Baird set up the Baird Television Development Company Ltd, which in 1928 made the first transatlantic television transmission, from London to Hartsdale, New York, and the first television programme for the BBC. In November 1929, Baird and Bernard Natan established France’s first television company, Télévision-Baird-Natan. Broadcast on the BBC on 14 July 1930, The Man with the Flower in His Mouth was the first drama shown on UK television. Baird televised the BBC’s first live outside broadcast with transmission of The Derby in 1931. He demonstrated a theatre television system, with a screen two feet by five feet (60 cm by 150 cm), in 1930 at the London Coliseum, Berlin, Paris, and Stockholm. By 1939 he had improved his theatre projection to televise a boxing match on a screen 15 ft (4.6 m) by 12 ft (3.7 m).

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1930s Baird television advertisement

From 1929 to 1932, the BBC transmitters were used to broadcast television programmes using the 30-line Baird system, and from 1932 to 1935, the BBC also produced the programmes in their own studio at 16 Portland Place. On 3 November 1936, from Alexandra Palace located on the high ground of the north London ridge, the BBC began alternating Baird 240-line transmissions with EMI’s electronic scanning system, which had recently been improved to 405 lines after a merger with Marconi. The Baird system at the time involved an intermediate film process, where footage was shot on cinefilm, which was rapidly developed and scanned. The trial was due to last 6 months but the BBC ceased broadcasts with the Baird system in February 1937, due in part to a disastrous fire in the Baird facilities at Crystal Palace. It was becoming apparent to the BBC that the Baird system would ultimately fail due in large part to the lack of mobility of the Baird system’s cameras, with their developer tanks, hoses, and cables.

Baird’s television systems were replaced by the electronic television system developed by the newly formed company EMI-Marconi under Isaac Shoenberg, which had access to patents developed by Vladimir Zworykin and RCA. Similarly, Philo T. Farnsworth’s electronic “Image Dissector” camera was available to Baird’s company via a patent-sharing agreement. However, the Image Dissector camera was found to be lacking in light sensitivity, requiring excessive levels of illumination. Baird used the Farnsworth tubes instead to scan cinefilm, in which capacity they proved serviceable though prone to drop-outs and other problems. Farnsworth himself came to London to Baird’s Crystal Palace laboratories in 1936, but was unable to fully solve the problem; the fire that burned Crystal Palace to the ground later that year further hampered the Baird company’s ability to compete.

Fully Electronic

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This live image of Paddy Naismith was used to demonstrate Baird’s first all-electronic colour television system, which used two projection CRTs. The two-colour image would be similar to the basic telechrome system.

Baird made many contributions to the field of electronic television after mechanical systems had taken a back seat. In 1939, he showed a system known today as hybrid colour using a cathode ray tube in front of which revolved a disc fitted with colour filters, a method taken up by CBS and RCA in the United States.

As early as 1940, Baird had started work on a fully electronic system he called the “Telechrome”. Early Telechrome devices used two electron guns aimed at either side of a phosphor plate. The phosphor was patterned so the electrons from the guns only fell on one side of the patterning or the other. Using cyan and magenta phosphors, a reasonable limited-colour image could be obtained. He also demonstrated the same system using monochrome signals to produce a 3D image (called “stereoscopic” at the time). In 1941, he patented and demonstrated this system of three-dimensional television at a definition of 500 lines. On 16 August 1944, he gave the world’s first demonstration of a practical fully electronic colour television display. His 600-line colour system used triple interlacing, using six scans to build each picture. Similar concepts were common through the 1940s and 50s, differing primarily in the way they re-combined the colours generated by the three guns. One of them, the Geer tube, was similar to Baird’s concept, but used small pyramids with the phosphors deposited on their outside faces, instead of Baird’s 3D patterning on a flat surface.

In 1943, the Hankey Committee was appointed to oversee the resumption of television broadcasts after the war. Baird persuaded them to make plans to adopt his proposed 1000-line Telechrome electronic colour system as the new post-war broadcast standard. The picture resolution on this system would have been comparable to today’s HDTV (High Definition Television). The Hankey Committee’s plan lost all momentum partly due to the challenges of postwar reconstruction. The monochrome 405-line standard remained in place until 1985 in some areas, and the 625-line system was introduced in 1964 and (PAL) colour in 1967. A demonstration of large screen three-dimensional television by the BBC was reported in March 2008, over 60 years after Baird’s demonstration.

Other Inventions


Some of Baird’s early inventions were not fully successful. In his twenties he tried to create diamonds by heating graphite and shorted out Glasgow’s electricity supply. Later Baird invented a glass razor, which was rust-resistant, but shattered. Inspired by pneumatic tyres he attempted to make pneumatic shoes, but his prototype contained semi-inflated balloons, which burst. He also invented a thermal undersock (the Baird undersock), which was moderately successful. Baird suffered from cold feet, and after a number of trials, he found that an extra layer of cotton inside the sock provided warmth.

Baird’s numerous other developments demonstrated his particular talent at invention. He was a visionary and began to dabble with electricity. In 1928, he developed an early video recording device, which he dubbed Phonovision. The system consisted of a large Nipkow disk attached by a mechanical linkage to a conventional 78-rpm record-cutting lathe. The result was a disc that could record and play back a 30-line video signal. Technical difficulties with the system prevented its further development, but some of the original phonodiscs have been preserved, and have since been restored by Donald McLean, a Scottish electrical engineer.

Baird’s other developments were in fibre-optics, radio direction finding, infrared night viewing and radar. There is discussion about his exact contribution to the development of radar, for his wartime defence projects have never been officially acknowledged by the UK government. According to Malcolm Baird, his son, what is known is that in 1926 Baird filed a patent for a device that formed images from reflected radio waves, a device remarkably similar to radar, and that he was in correspondence with the British government at the time. The radar contribution is in dispute. According to some experts, Baird’s “noctovision” is not radar. Unlike radar (except Doppler radar), Noctovision is incapable of determining the distance to the scanned subject. Noctovision also cannot determine the coordinates of the subject in three-dimensional space.

Later Years


From December 1944, Logie Baird lived at 1 Station Road, Bexhill-on-Sea, East Sussex, immediately north of the station and subsequently died there on 14 June 1946 after suffering a stroke in February. The house was demolished in 2007 and the site is now apartments named Baird Court. Logie Baird is buried with his mother, father and wife in Helensburgh Cemetery, Argyll, Scotland.

Honours and Portrayals


Blue plaque erected by Greater London Council at 3 Crescent Wood Road, Sydenham, London

Australian television’s Logie Awards were named in honour of John Logie Baird’s contribution to the invention of the television. Baird became the only deceased subject of This Is Your Life when he was honoured by Eamonn Andrews at the BBC Television Theatre in 1957.

He was played by Michael Gwynn (and also by Andrew Irvine, who played him as a boy) in the 1957 TV film A Voice in Vision and by Robert McIntosh in the 1986 TV drama The Fools on the Hill.

In 2014, the Society of Motion Picture and Television Engineers (SMPTE) inducted Logie Baird into The Honor Roll, which “posthumously recognizes individuals who were not awarded Honorary Membership during their lifetimes but whose contributions would have been sufficient to warrant such an honor”.

On 26 January 2016, the search engine Google released a Google Doodle to mark the 90th anniversary of Logie Baird’s first public demonstration of live television.

Nikola Tesla

From Wikipedia, the free encyclopedia

N.Tesla

Nikola Tesla (/ˈtɛslə/; Serbian Cyrillic: Никола Тесла Serbo-Croatian pronunciation: [nikoːla tesla]; 10 July 1856 – 7 January 1943) was a Serbian-American inventor, electrical engineer, mechanical engineer, physicist, and futurist who is best known for his contributions to the design of the modern alternating current (AC) electricity supply system.

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Born and raised in the Austrian Empire, Tesla received an advanced education in engineering and physics in the 1870s and gained practical experience in the early 1880s working in telephony and at Continental Edison in the new electric power industry. He emigrated to the United States in 1884, where he would become a naturalized citizen. He worked for a short time at the Edison Machine Works in New York City before he struck out on his own. With the help of partners to finance and market his ideas, Tesla set up laboratories and companies in New York to develop a range of electrical and mechanical devices. His alternating current (AC) induction motor and related polyphase AC patents, licensed by Westinghouse Electric in 1888, earned him a considerable amount of money and became the cornerstone of the polyphase system which that company would eventually market.

Attempting to develop inventions he could patent and market, Tesla conducted a range of experiments with mechanical oscillators/generators, electrical discharge tubes, and early X-ray imaging. He also built a wireless-controlled boat, one of the first ever exhibited. Tesla became well known as an inventor and would demonstrate his achievements to celebrities and wealthy patrons at his lab, and was noted for his showmanship at public lectures.

Throughout the 1890s, Tesla pursued his ideas for wireless lighting and worldwide wireless electric power distribution in his high-voltage, high-frequency power experiments in New York and Colorado Springs. In 1893, he made pronouncements on the possibility of wireless communication with his devices. Tesla tried to put these ideas to practical use in his unfinished Wardenclyffe Tower project, an intercontinental wireless communication and power transmitter, but ran out of funding before he could complete it.

After Wardenclyffe, Tesla went on to try to develop a series of inventions in the 1910s and 1920s with varying degrees of success. Having spent most of his money, he lived in a series of New York hotels, leaving behind unpaid bills. The nature of his earlier work and the pronouncements he made to the press later in life earned him the reputation of an archetypal “mad scientist” in American popular culture. Tesla died in New York City in January 1943. His work fell into relative obscurity following his death, but in 1960, the General Conference on Weights and Measures named the SI unit of magnetic flux density the tesla in his honor. There has been a resurgence in popular interest in Tesla since the 1990s.

Early Years


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Rebuilt, Tesla’s house (parish hall) in Smiljan, now in Croatia, where he was born, and the rebuilt church, where his father served. During the Yugoslav Wars, several of the buildings were severely damaged by fire. They were restored and reopened in 2006.

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Tesla’s baptismal record, 28 June 1856

Nikola Tesla was born an ethnic Serb in the village Smiljan, Lika county, in the Austrian Empire (present day Croatia), on 10 July [O.S. 28 June] 1856. His father, Milutin Tesla (1819–1879), was an Eastern Orthodox priest. Tesla’s mother, Đuka Tesla (née Mandić; 1822–1892), whose father was also an Orthodox priest, had a talent for making home craft tools and mechanical appliances and the ability to memorize Serbian epic poems. Đuka had never received a formal education. Tesla credited his eidetic memory and creative abilities to his mother’s genetics and influence. Tesla’s progenitors were from western Serbia, near Montenegro.

Tesla was the fourth of five children. He had three sisters, Milka, Angelina and Marica, and an older brother named Dane, who was killed in a horse riding accident when Tesla was aged five. In 1861, Tesla attended primary school in Smiljan where he studied German, arithmetic, and religion. In 1862, the Tesla family moved to the nearby Gospić, Lika where Tesla’s father worked as parish priest. Nikola completed primary school, followed by middle school.

In 1870, Tesla moved far north to Karlovac  to attend high school at the Higher Real Gymnasium. The classes were held in German, as it was a school within the Austro-Hungarian Military Frontier.

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Tesla’s father, Milutin, was Orthodox priest in the village of Smiljan

Tesla would later write that he became interested in demonstrations of electricity by his physics professor. Tesla noted that these demonstrations of this “mysterious phenomena” made him want “to know more of this wonderful force”. Tesla was able to perform integral calculus in his head, which prompted his teachers to believe that he was cheating. He finished a four-year term in three years, graduating in 1873.

In 1873, Tesla returned to Smiljan. Shortly after he arrived, he contracted cholera, was bedridden for nine months and was near death multiple times. Tesla’s father, in a moment of despair, (who had originally wanted him to enter the priesthood)  promised to send him to the best engineering school if he recovered from the illness.

In 1874, Tesla evaded conscription into the Austro-Hungarian Army in Smiljan by running away southeast of Lika to Tomingaj, near Gračac. There he explored the mountains wearing hunter’s garb. Tesla said that this contact with nature made him stronger, both physically and mentally. He read many books while in Tomingaj and later said that Mark Twain’s works had helped him to miraculously recover from his earlier illness.

In 1875, Tesla enrolled at Austrian Polytechnic in Graz, Austria, on a Military Frontier scholarship. During his first year, Tesla never missed a lecture, earned the highest grades possible, passed nine exams (nearly twice as many as required), started a Serb cultural club, and even received a letter of commendation from the dean of the technical faculty to his father, which stated, “Your son is a star of first rank.” During his second year, Tesla came into conflict with Professor Poeschl over the Gramme dynamo, when Tesla suggested that commutators were not necessary.

Tesla claimed that he worked from 3 a.m. to 11 p.m., no Sundays or holidays excepted. He was “mortified when [his] father made light of [those] hard won honors.” After his father’s death in 1879, Tesla found a package of letters from his professors to his father, warning that unless he were removed from the school, Tesla would die through overwork. At the end of his second year, Tesla lost his scholarship and became addicted to gambling. During his third year, Tesla gambled away his allowance and his tuition money, later gambling back his initial losses and returning the balance to his family. Tesla said that he “conquered [his] passion then and there,” but later in the U.S. he was again known to play billiards. When examination time came, Tesla was unprepared and asked for an extension to study, but was denied. He did not receive grades for the last semester of the third year and he never graduated from the university.

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Tesla aged 23, c. 1879

In December 1878, Tesla left Graz and severed all relations with his family to hide the fact that he dropped out of school. His friends thought that he had drowned in the nearby Mur River. Tesla moved to Maribor, where he worked as a draftsman for 60 florins per month. He spent his spare time playing cards with local men on the streets.

In March 1879, Tesla’s father went to Maribor to beg his son to return home, but he refused. Nikola suffered a nervous breakdown around the same time. On 24 March 1879, Tesla was returned to Gospić under police guard for not having a residence permit.

On 17 April 1879, Milutin Tesla died at the age of 60 after contracting an unspecified illness. Some sources say that he died of a stroke. During that year, Tesla taught a large class of students in his old school in Gospić.

In January 1880, two of Tesla’s uncles put together enough money to help him leave Gospić for Prague, where he was to study. He arrived too late to enroll at Charles-Ferdinand University; he had never studied Greek, a required subject; and he was illiterate in Czech, another required subject. Tesla did, however, attend lectures in philosophy at the university as an auditor and he did not receive grades for the courses.

Working at Budapest Telephone Exchange

In 1881, Tesla moved to Budapest, Hungary, to work under Tivadar Puskás at a telegraph company, the Budapest Telephone Exchange. Upon arrival, Tesla realized that the company, then under construction, was not functional, so he worked as a draftsman in the Central Telegraph Office instead. Within a few months, the Budapest Telephone Exchange became functional, and Tesla was allocated the chief electrician position. During his employment, Tesla made many improvements to the Central Station equipment and claimed to have perfected a telephone repeater or amplifier, which was never patented nor publicly described.

Working at Edison


In 1882, Tivadar Puskás got Tesla another job in Paris with the Continental Edison Company. Tesla began working in what was then a brand new industry, installing indoor incandescent lighting citywide in the form of an electric power utility. The company had several subdivisions and Tesla worked at the Société Electrique Edison, the division in the Ivry-sur-Seine suburb of Paris in charge of installing the lighting system. There he gained a great deal of practical experience in electrical engineering. Management took notice of his advanced knowledge in engineering and physics and soon had him designing and building improved versions of generating dynamos and motors. They also sent him on to troubleshoot engineering problems at other Edison utilities being built around France and in Germany.

A move to the US

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Edison Machine Works on Goerck Street, New York. Tesla found the change from cosmopolitan Europe to working at this shop, located amongst the tenements on Manhattan’s lower east side, a “painful surprise”.

In 1884, Edison manager Charles Batchelor, who had been overseeing the Paris installation, was brought back to the US to manage the Edison Machine Works, a manufacturing division situated in New York City, and asked that Tesla be brought to the US as well. In June 1884, Tesla emigrated to the United States. He began working almost immediately at the Machine Works on Manhattan’s Lower East Side, an overcrowded shop with a workforce of several hundred machinists, laborers, managing staff, and 20 “field engineers” struggling with the task of building the large electric utility in that city. As in Paris, Tesla was working on troubleshooting installations and improving generators. Historian W. Bernard Carlson notes Tesla may have met company founder Thomas Alva Edison only a couple of times. One of those times was noted in Tesla’s autobiography where, after staying up all night repairing the damaged dynamos on the ocean liner SS Oregon, he ran into Batchelor and Edison, who made a quip about their “Parisian” being out all night. After Tesla told them he had been up all night fixing the Oregon Edison commented to Batchelor that “this is a damned good man.” One of the projects given to Tesla was to develop an arc lamp-based street lighting system. Arc lighting was the most popular type of street lighting but it required high voltages and was incompatible with the Edison low-voltage incandescent system, causing the company to lose contracts in cities that wanted street lighting as well. Tesla’s designs were never put into production, possibly because of technical improvements in incandescent street lighting or because of an installation deal that Edison cut with an arc lighting company.

Tesla had been working at the Machine Works for a total of six months when he quit. What event precipitated his leaving is unclear. It may have been over a bonus he did not receive, either for redesigning generators or for the arc lighting system that was shelved. Tesla had previous run-ins with the Edison company over unpaid bonuses he believed he had earned. In his own biography, Tesla stated the manager of the Edison Machine Works offered a $50,000 bonus to design “twenty-four different types of standard machines” “but it turned out to be a practical joke”. Later versions of this story have Thomas Edison himself offering and then reneging on the deal, quipping “Tesla, you don’t understand our American humor.” The size of the bonus in either story has been noted as odd since Machine Works manager Batchelor was stingy with pay and the company did not have that amount of cash (equivalent to $12 million today) on hand. Tesla’s diary contains just one comment on what happened at the end of his employment, a note he scrawled across the two pages covering December 7, 1884, to January 4, 1885, saying “Good by to the Edison Machine Works”.

Tesla Electric Light & Manufacturing


Soon after leaving the Edison company, Tesla was working on patenting an arc lighting system, possibly the same one he had developed at Edison. In March 1885, he met with patent attorney Lemuel W. Serrell, the same attorney used by Edison, to obtain help with submitting the patents. Serrell introduced Tesla to two businessmen, Robert Lane and Benjamin Vail, who agreed to finance an arc lighting manufacturing and utility company in Tesla’s name, the Tesla Electric Light & Manufacturing. Tesla worked for the rest of the year obtaining the patents that included an improved DC generator, the first patents issued to Tesla in the US, and building and installing the system in Rahway, New Jersey Tesla’s new system gained notice in the technical press, which commented on its advanced features.

The investors showed little interest in Tesla’s ideas for new types of alternating current motors and electrical transmission equipment. After the utility was up and running in 1886, they decided that the manufacturing side of the business was too competitive and opted to simply run an electric utility. They formed a new utility company, abandoning Tesla’s company and leaving the inventor penniless. Tesla even lost control of the patents he had generated, since he had assigned them to the company in exchange for stock. He had to work at various electrical repair jobs and as a ditch digger for $2 per day. Later in life Tesla would recount that part of 1886 as a time of hardship, writing “My high education in various branches of science, mechanics and literature seemed to me like a mockery”.

AC and the Induction Motor


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Drawing from U.S. Patent 381,968, illustrating principle of Tesla’s alternating current induction motor

In late 1886, Tesla met Alfred S. Brown, a Western Union superintendent, and New York attorney Charles F. Peck. The two men were experienced in setting up companies and promoting inventions and patents for financial gain.3] Based on Tesla’s new ideas for electrical equipment, including a thermo-magnetic motor idea, they agreed to back the inventor financially and handle his patents. Together they formed the Tesla Electric Company in April 1887, with an agreement that profits from generated patents would go 1/3 to Tesla, 1/3 to Peck and Brown, and 1/3 to fund development. They set up a laboratory for Tesla at 89 Liberty Street in Manhattan, where he worked on improving and developing new types of electric motors, generators, and other devices.

In 1887, Tesla developed an induction motor that ran on alternating current (AC), a power system format that was rapidly expanding in Europe and the United States because of its advantages in long-distance, high-voltage transmission. The motor used polyphase current, which generated a rotating magnetic field to turn the motor (a principle that Tesla claimed to have conceived in 1882). This innovative electric motor, patented in May 1888, was a simple self-starting design that did not need a commutator, thus avoiding sparking and the high maintenance of constantly servicing and replacing mechanical brushes.

Along with getting the motor patented, Peck and Brown arranged to get the motor publicized, starting with independent testing to verify it was a functional improvement, followed by press releases sent to technical publications for articles to run concurrent with the issue of the patent. Physicist William Arnold Anthony (who tested the motor) and Electrical World magazine editor Thomas Commerford Martin arranged for Tesla to demonstrate his AC motor on 16 May 1888 at the American Institute of Electrical Engineers. Engineers working for the Westinghouse Electric & Manufacturing Company reported to George Westinghouse that Tesla had a viable AC motor and related power system – something Westinghouse needed for the alternating current system he was already marketing. Westinghouse looked into getting a patent on a similar commutator-less, rotating magnetic field-based induction motor developed in 1885 and presented in a paper in March 1888 by Italian physicist Galileo Ferraris, but decided that Tesla’s patent would probably control the market.

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Nikola Tesla’s AC dynamo-electric machine (AC Electric generator) in an 1888 U.S. Patent 390,721

In July 1888, Brown and Peck negotiated a licensing deal with George Westinghouse for Tesla’s polyphase induction motor and transformer designs for $60,000 in cash and stock and a royalty of $2.50 per AC horsepower produced by each motor. Westinghouse also hired Tesla for one year for the large fee of $2,000 ($54,500 in today’s dollars) per month to be a consultant at the Westinghouse Electric & Manufacturing Company’s Pittsburgh labs.

During that year, Tesla worked in Pittsburgh, helping to create an alternating current system to power the city’s streetcars. He found it a frustrating period because of conflicts with the other Westinghouse engineers over how best to implement AC power. Between them, they settled on a 60-cycle AC system that Tesla proposed (to match the working frequency of Tesla’s motor), but they soon found that it would not work for streetcars, since Tesla’s induction motor could run only at a constant speed. They ended up using a DC traction motor instead.

Market Turmoil

Tesla’s demonstration of his induction motor and Westinghouse’s subsequent licensing of the patent, both in 1888, came at the time of extreme competition between electric companies. The three big firms, Westinghouse, Edison, and Thompson-Houston, were trying to grow in a capital-intensive business while financially undercutting each other. There was even a “War of Currents” propaganda campaign going on with Edison Electric trying to claim their direct current system was better and safer than the Westinghouse alternating current system. Competing in this market meant Westinghouse would not have the cash or engineering resources to develop Tesla’s motor and the related polyphase system right away.

Two years after signing the Tesla contract, Westinghouse Electric was in trouble. The near collapse of Barings Bank in London triggered the financial panic of 1890, causing investors to call in their loans to W.E. The sudden cash shortage forced the company to refinance its debts. The new lenders demanded that Westinghouse cut back on what looked like excessive spending on acquisition of other companies, research, and patents, including the per motor royalty in the Tesla contract. At that point, the Tesla induction motor had been unsuccessful and was stuck in development. Westinghouse was paying a $15,000-a-year guaranteed royalty even though operating examples of the motor were rare and polyphase power systems needed to run it were even rarer. In early 1891, George Westinghouse explained his financial difficulties to Tesla in stark terms, saying that, if he did not meet the demands of his lenders, he would no longer be in control of Westinghouse Electric and Tesla would have to “deal with the bankers” to try to collect future royalties. The advantages of having Westinghouse continue to champion the motor probably seemed obvious to Tesla and he agreed to release the company from the royalty payment clause in the contract. Six years later Westinghouse would purchase Tesla’s patent for a lump sum payment of $216,000 as part of a patent-sharing agreement signed with General Electric (a company created from the 1892 merger of Edison and Thompson-Houston).

New York Laboratories


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Mark Twain in Tesla’s South Fifth Avenue laboratory, 1894

The money Tesla made from licensing his AC patents made him independently wealthy and gave him the time and funds to pursue his own interests. In 1889, Tesla moved out of the Liberty Street shop Peck and Brown had rented and for the next dozen years would work out of a series of workshop/laboratory spaces in Manhattan. These included a lab at 175 Grand Street (1889–1892), the fourth floor of 33–35 South Fifth Avenue (1892–1895), and sixth and seventh floors of 46 & 48 East Houston Street (1895–1902). Tesla and his hired staff would conduct some of his most significant work in these workshops.

Tesla Coil

In the summer of 1889, Tesla traveled to the 1889 Exposition Universelle in Paris and learned of Heinrich Hertz’ 1886–88 experiments that proved the existence of electromagnetic radiation, including radio waves. Tesla found this new discovery “refreshing” and decided to explore it more fully. In repeating, and then expanding on, these experiments, Tesla tried powering a Ruhmkorff coil with a high speed alternator he had been developing as part of an improved arc lighting system but found that the high frequency current overheated the iron core and melted the insulation between the primary and secondary windings in the coil. To fix this problem Tesla came up with his Tesla coil with an air gap instead of insulating material between the primary and secondary windings and an iron core that could be moved to different positions in or out of the coil.

Citizenship

On 30 July 1891, aged 35, Tesla became a naturalized citizen of the United States. In the same year, he patented his Tesla coil.

Wireless Lighting

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Tesla demonstrating wireless lighting by “electrostatic induction” during an 1891 lecture at Columbia College via two long Geissler tubes (similar to neon tubes) in his hands.

After 1890, Tesla experimented with transmitting power by inductive and capacitive coupling using high AC voltages generated with his Tesla coil. He attempted to develop a wireless lighting system based on near-field inductive and capacitive coupling and conducted a series of public demonstrations where he lit Geissler tubes and even incandescent light bulbs from across a stage. He would spend most of the decade working on variations of this new form of lighting with the help of various investors but none of the ventures succeeded in making a commercial product out of his findings.

In 1893 at St. Louis, Missouri, the Franklin Institute in Philadelphia, Pennsylvania and the National Electric Light Association, Tesla told onlookers that he was sure a system like his could eventually conduct “intelligible signals or perhaps even power to any distance without the use of wires” by conducting it through the Earth.

Tesla served as a vice-president of the American Institute of Electrical Engineers from 1892 to 1894, the forerunner of the modern-day IEEE (along with the Institute of Radio Engineers).

Steam-powered oscillating generator

Trying to come up with a better way to generate alternating current, Tesla developed a steam powered reciprocating electricity generator. He patented it in 1893 and introduced it at the Chicago World’s Columbian Exposition that year. Steam would be forced into the oscillator and rush out through a series of ports, pushing a piston up and down that was attached to an armature. The magnetic armature vibrated up and down at high speed, producing an alternating magnetic field. This induced alternating electric current in the wire coils located adjacent. It did away with the complicated parts of a steam engine/generator, but never caught on as a feasible engineering solution to generate electricity.

Polyphase System and the Columbian Exposition

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A Westinghouse display of the “Tesla Polyphase System” at Chicago’s 1893 Columbian Exposition

At the beginning of 1893, Westinghouse engineer Benjamin Lamme had made great progress developing an efficient version of Tesla’s induction motor, and Westinghouse Electric started branding their complete polyphase AC system as the “Tesla Polyphase System”. They believed that Tesla’s patents gave them patent priority over other AC systems.

Westinghouse Electric asked Tesla to participate in the 1893 World’s Columbian Exposition in Chicago where the company had a large space in a building devoted to electrical exhibits. Westinghouse Electric won the bid to light the Exposition with alternating current and it was a key event in the history of AC power, as the company demonstrated to the American public the safety, reliability, and efficiency of a fully integrated alternating current system. Tesla showed a series of electrical effects related to alternating current as well as his wireless lighting system, using a demonstration he had previously performed throughout America and Europe; these included using high-voltage, high-frequency alternating current to light a wireless gas-discharge lamp.

An observer noted:

Within the room were suspended two hard-rubber plates covered with tin foil. These were about fifteen feet apart, and served as terminals of the wires leading from the transformers. When the current was turned on, the lamps or tubes, which had no wires connected to them, but lay on a table between the suspended plates, or which might be held in the hand in almost any part of the room, were made luminous. These were the same experiments and the same apparatus shown by Tesla in London about two years previous, “where they produced so much wonder and astonishment”.

Tesla also explained the principles of the rotating magnetic field in an induction motor by demonstrating how to make a copper egg stand on end, using a device that he constructed known as the Egg of Columbus and introduced his new steam powered oscillator AC generator.

Consulting on Niagara

In 1893, Edward Dean Adams, who headed up the Niagara Falls Cataract Construction Company, sought Tesla’s opinion on what system would be best to transmit power generated at the falls. Over several years, there had been a series of proposals and open competitions on how best to use power generated by the falls. Among the systems proposed by several US and European companies were two-phase and three-phase AC, high-voltage DC, and compressed air. Adams pumped Tesla for information about the current state of all the competing systems. Tesla advised Adams that a two-phased system would be the most reliable, and that there was a Westinghouse system to light incandescent bulbs using two-phase alternating current. The company awarded a contract to Westinghouse Electric for building a two-phase AC generating system at the Niagara Falls, based on Tesla’s advice and Westinghouse’s demonstration at the Columbian Exposition that they could build a complete AC system. At the same time, a further contract was awarded to General Electric to build the AC distribution system.

The Nikola Tesla Company

In 1895, Edward Dean Adams, impressed with what he saw when he toured Tesla’s lab, agreed to help found the Nikola Tesla Company, set up to fund, develop, and market a variety of previous Tesla patents and inventions as well as new ones. Alfred Brown signed on, bringing along patents developed under Peck and Brown. The board was filled out with William Birch Rankine and Charles F. Coaney. It found few investors; the mid-1890s was a tough time financially, and the wireless lighting and oscillators patents it was set up to market never panned out. The company would handle Tesla’s patents for decades to come.

Lab Fire

In the early morning hours of March 13, 1895, the South Fifth Avenue building that housed Tesla’s lab caught fire. It started in the basement of the building and was so intense Tesla’s 4th floor lab burned and collapsed into the second floor. The fire not only set back Tesla’s ongoing projects, it destroyed a collection of early notes and research material, models, and demonstration pieces, including many that had been exhibited at the 1893 Worlds Colombian Exposition. Tesla told The New York Times “I am in too much grief to talk. What can I say?” After the fire Tesla moved to 46 & 48 East Houston Street and rebuilt his lab on the 6th and 7th floors.

X-ray Experimentation

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X-ray of a hand, taken by Tesla

Starting in 1894, Tesla began investigating what he referred to as radiant energy of “invisible” kinds after he had noticed damaged film in his laboratory in previous experiments (later identified as “Roentgen rays” or “X-Rays”). His early experiments were with Crookes tubes, a cold cathode electrical discharge tube. Tesla may have inadvertently captured an X-ray image—predating, by a few weeks, Wilhelm Röntgen’s December 1895 announcement of the discovery of x-rays—when he tried to photograph Mark Twain illuminated by a Geissler tube, an earlier type of gas discharge tube. The only thing captured in the image was the metal locking screw on the camera lens.

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In 1898, Tesla demonstrated a radio-controlled boat which he hoped to sell as a guided torpedo to navies around the world.

In March 1896, after hearing of Wilhelm Röntgen’s discovery of X-ray and X-ray imaging (radiography), Tesla proceeded to do his own experiments in X-ray imaging, developing a high energy single terminal vacuum tube of his own design that had no target electrode and that worked from the output of the Tesla Coil (the modern term for the phenomenon produced by this device is bremsstrahlung or braking radiation). In his research, Tesla devised several experimental setups to produce X-rays. Tesla held that, with his circuits, the “instrument will … enable one to generate Roentgen rays of much greater power than obtainable with ordinary apparatus.”

Tesla noted the hazards of working with his circuit and single-node X-ray-producing devices. In his many notes on the early investigation of this phenomenon, he attributed the skin damage to various causes. He believed early on that damage to the skin was not caused by the Roentgen rays, but by the ozone generated in contact with the skin, and to a lesser extent, by nitrous acid. Tesla incorrectly believed that X-rays were longitudinal waves, such as those produced in waves in plasmas. These plasma waves can occur in force-free magnetic fields.

On 11 July 1934, the New York Herald Tribune published an article on Tesla, in which he recalled an event that would occasionally take place while experimenting with his single-electrode vacuum tubes; a minute particle would break off the cathode, pass out of the tube, and physically strike him:

Tesla said he could feel a sharp stinging pain where it entered his body, and again at the place where it passed out. In comparing these particles with the bits of metal projected by his “electric gun,” Tesla said, “The particles in the beam of force … will travel much faster than such particles … and they will travel in concentrations.”

Radio Remote Control

In 1898, Tesla demonstrated a boat that used a coherer-based radio control—which he dubbed “telautomaton”—to the public during an electrical exhibition at Madison Square Garden. The crowd that witnessed the demonstration made outrageous claims about the workings of the boat, such as magic, telepathy, and being piloted by a trained monkey hidden inside. Tesla tried to sell his idea to the U.S. military as a type of radio-controlled torpedo, but they showed little interest. Remote radio control remained a novelty until World War I and afterward, when a number of countries used it in military programs. Tesla took the opportunity to further demonstrate “Teleautomatics” in an address to a meeting of the Commercial Club in Chicago, while he was travelling to Colorado Springs, on 13 May 1899.

Wireless Power


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Tesla sitting in front of a spiral coil used in his wireless power experiments at his East Houston St. laboratory

From the 1890s through 1906, Tesla spent a great deal of his time and fortune on a series of projects trying to develop the transmission of electrical power without wires. It was an expansion of his idea of using coils to transmit power he had been demonstrating in wireless lighting. He could see this as not only a way to transmit large amounts of power around the world but also, as he had pointed out in his earlier lectures, a way to transmit worldwide communications.

At the time Tesla was formulating his ideas there was no feasible way to wirelessly transmit communication signals over long distances, let alone large amounts of power. Tesla had studied radio waves early on, at the time called “Hertzian waves” after their discovery by Hertz, and come to the conclusion that the theory on them was incorrect. Also, this new form of radiation was widely considered at the time to be a short-distance phenomenon that seemed to die out in less than a mile. Tesla noted that, even if theories on radio waves were true, they were totally worthless for his intended purposes since this form of “invisible light” would diminish over distance just like any other radiation and would travel in straight lines right out into space becoming “hopelessly lost”.

By the mid 1890s, Tesla was working on the idea that he might be able to conduct electricity long distance through the Earth or the atmosphere and began working on experiments to test this idea including setting up a large resonance transformer magnifying transmitter in his East Houston Street lab. Seeming to borrow from a common idea at the time that the Earth’s atmosphere was conductive, he proposed a system composed of balloons suspending, transmitting, and receiving, electrodes in the air above 30,000 feet (9,100 m) in altitude, where he thought the lower pressure would allow him to send high voltages (millions of volts) long distances.

Colorado Springs

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Tesla’s Colorado Springs laboratory

To further study the conductive nature of low pressure air, Tesla set up an experimental station at high altitude in Colorado Springs during 1899. There he could safely operate much larger coils than in the cramped confines of his New York lab and an associate had made an arrangement for the El Paso Power Company to supply alternating current free of charge. To fund his experiments he convinced John Jacob Astor IV to invest $100,000 to become a majority share holder in the Nikola Tesla Company. Astor thought he was primarily investing in the new wireless lighting system. Instead, Tesla used the money to fund his Colorado Springs experiments. Upon his arrival, he told reporters that he planned to conduct wireless telegraphy experiments, transmitting signals from Pikes Peak to Paris.

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A multiple exposure picture of Tesla sitting next to his “magnifying transmitter” generating millions of volts. The 7-metre (23 ft) long arcs were not part of the normal operation, but only produced for effect by rapidly cycling the power switch.

There he conducted experiments with a large coil operating in the megavolts range, producing artificial lightning (and thunder) consisting of millions of volts and up to 135 feet (41 m) long discharges and, at one point, inadvertently burned out the generator in El Paso, causing a power outage. The observations he made of the electronic noise of lightning strikes, led him to (incorrectly) conclude  that he could use the entire globe of the Earth to conduct electrical energy.

During his time at his laboratory Tesla observed unusual signals from his receiver which he speculated to be communications from another planet. He mentioned them in a letter to a reporter in December 1899 and to the Red Cross Society in December 1900 Reporters treated it as a sensational story and jumped to the conclusion Tesla was hearing signals from Mars. He expanded on the signals he heard in a 9 February 1901 Collier’s Weekly article “Talking With Planets” where he said it had not been immediately apparent to him that he was hearing “intelligently controlled signals” and that the signals could come from Mars, Venus, or other planets. It has been hypothesized that he may have intercepted Guglielmo Marconi’s European experiments in July 1899—Marconi may have transmitted the letter S (dot/dot/dot) in a naval demonstration, the same three impulses that Tesla hinted at hearing in Colorado—or signals from another experimenter in wireless transmission.

Tesla had an agreement with the editor of The Century Magazine to produce an article on his findings. The magazine sent a photographer to Colorado to photograph the work being done there. The article, titled “The Problem of Increasing Human Energy”, appeared in the June, 1900 edition of the magazine. He explained the superiority of the wireless system he envisioned but the article was more of a lengthy philosophical treatise than an understandable scientific description of his work illustrated with what were to become iconic images of Tesla and his Colorado Springs experiments.

Wardenclyffe

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Tesla’s Wardenclyffe plant on Long Island in 1904. From this facility, Tesla hoped to demonstrate wireless transmission of electrical energy across the Atlantic.

Tesla made the rounds in New York trying to find investors for what he thought would be a viable system of wireless transmission, wining and dining them at the Waldorf-Astoria’s Palm Garden (the hotel where he was living at the time), The Players Club and Delmonico’s. In March, 1901, he obtained $150,000 ($4,412,400 in today’s dollars) from J. Pierpont Morgan in return for a 51% share of any generated wireless patents and began planning the Wardenclyffe Tower facility to be built in Shoreham, New York, 100 miles (161 km) east of the city on the North Shore of Long Island.

By July 1901, Tesla had expanded his plans to build a more powerful transmitter to leap ahead of Marconi’s radio based system, which Tesla thought was a copy of his own system. He approached Morgan to ask for more money to build the larger system but Morgan refused to supply any further funds. In December 1901, Marconi successfully transmitted the letter S from England to Newfoundland, defeating Tesla in the race to be first to complete such a transmission. A month after Marconi’s success Tesla tried to get Morgan to back an even larger plan to transmit messages and power by controlling “vibrations throughout the globe”. Over the next five years, Tesla wrote more than 50 letters to Morgan, pleading for and demanding additional funding to complete the construction of Wardenclyffe. Tesla continued the project for another nine months into 1902. The tower was erected to its full 187 feet (57 m). In June 1902, Tesla moved his lab operations from Houston Street to Wardenclyffe.

Investors on Wall Street were putting their money into Marconi’s system and some in the press began turning against Tesla’s project, claiming it was a hoax  The project came to a halt in 1905 and in 1906, the financial problems and other events may have led to what Tesla biographer Marc J. Seifer suspects was a nervous breakdown on Tesla’s part. Tesla mortgaged the Wardenclyffe property to cover his debts at the Waldorf-Astoria, which eventually mounted to $20,000 ($488,600 in today’s dollars). He lost the property in foreclosure in 1915 and in 1917 the Tower was demolished by the new owner to make the land a more viable real estate asset.

Later Years


After Wardencyiffe closed, Tesla continued to write to Morgan; after “the great man” died, Tesla wrote to his son Jack Morgan, trying to get further funding for the project. In 1906, he opened offices at 165 Broadway in Manhattan, trying to raise further funds by developing and marketing his patents. He went on to have offices at the Metropolitan Life Tower from 1910 to 1914; rented for a few months at the Woolworth Building, moving out because he could not afford the rent; and then to office space at 8 West 40th Street from 1915 to 1925. After moving to 8 West 40th Street, he was effectively bankrupt. Most of his patents had run out and he was having trouble with the new inventions he was trying to develop.

Bladeless Turbine

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Tesla’s bladeless turbine design

On his 50th birthday, in 1906, Tesla demonstrated a 200 horsepower (150 kilowatts) 16,000 rpm bladeless turbine. During 1910–1911 at the Waterside Power Station in New York, several of his bladeless turbine engines were tested at 100–5,000 hp. Tesla worked with several companies including the period 1919–1922 working in Milwaukee for Allis-Chalmers. He spent most of his time trying to perfect the Tesla turbine with Hans Dahlstrand, the head engineer at the company, but engineering difficulties meant it was never made into a practical device. Tesla did license the idea to a precision instrument company and it found use in the form of luxury car speedometers and other instruments.

Wireless Lawsuits

When World War I broke out, the British cut the transatlantic telegraph cable linking the US to Germany in order to control the flow of information between the two countries. They also tried to shut off German wireless communication to and from the US by having the US Marconi Company sue the German radio company Telefunken for patent infringement. Telefunken brought in the physicist Jonathan Zenneck and Karl Ferdinand Braun for their defense and hired Tesla as a witness for two years for $1,000 a month. The case stalled and then went moot when the US entered the war against Germany in 1917.

In 1915, Tesla attempted to sue the Marconi Company for infringement of his wireless tuning patents. Marconi’s initial radio patent had been awarded in the US in 1897, but his 1900 patent submission covering improvements to radio transmission had been rejected several times, before it was finally approved in 1904, on the grounds that it infringed on other existing patents including two 1897 Tesla wireless power tuning patents. Tesla’s 1915 case went nowhere, but in a related case, where the Marconi Company tried to sue the US government over WWI patent infringements, a Supreme Court of the United States 1943 decision restored the prior patents of Oliver Lodge, John Stone, and Tesla. The court declared that their decision had no bearing on Marconi’s claim as the first to achieve radio transmission, just that since Marconi’s claim to certain patented improvements were questionable, the company could not claim infringement on those same patents.

Nobel Prize Rumors

On 6 November 1915, a Reuters news agency report from London had the 1915 Nobel Prize in Physics awarded to Thomas Edison and Nikola Tesla; however, on 15 November, a Reuters story from Stockholm stated the prize that year was being awarded to Sir William Henry Bragg and William Lawrence Bragg “for their services in the analysis of crystal structure by means of X-rays.” There were unsubstantiated rumors at the time that either Tesla or Edison had refused the prize. The Nobel Foundation said, “Any rumor that a person has not been given a Nobel Prize because he has made known his intention to refuse the reward is ridiculous”; a recipient could decline a Nobel Prize only after he is announced a winner.

There have been subsequent claims by Tesla biographers that Edison and Tesla were the original recipients and that neither was given the award because of their animosity toward each other; that each sought to minimize the other’s achievements and right to win the award; that both refused ever to accept the award if the other received it first; that both rejected any possibility of sharing it; and even that a wealthy Edison refused it to keep Tesla from getting the $20,000 prize money.

In the years after these rumors, neither Tesla nor Edison won the prize (although Edison did receive one of 38 possible bids in 1915 and Tesla did receive one of 38 possible bids in 1937).

Other ideas, awards, and patents

Tesla won numerous medals and awards over this time. They include:

  • Order of St. Sava, II Class, Government of Serbia (1892)
  • Elliott Cresson Medal (1894)
  • Order of Prince Danilo I (1895)
  • AIEE Edison Medal (1917).
  • Order of St. Sava, I Class, Government of Yugoslavia (1926)
  • Order of the Yugoslav Crown (1931)
  • John Scott Medal (1934)
  • Order of the White Eagle, I Class, Government of Yugoslavia (1936)
  • Order of the White Lion, I Class, Government of Czechoslovakia (1937)
  • University of Paris Medal (1937)
  • The Medal of the University St. Clement of Ochrida, Sofia, Bulgaria (1939)

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Second banquet meeting of the Institute of Radio Engineers, 23 April 1915. Tesla seen standing in the center.

Tesla attempted to market several devices based on the production of ozone. These included his 1900 Tesla Ozone Company selling an 1896 patented device based on his Tesla Coil, used to bubble ozone through different types of oils to make a therapeutic gel. He also tried to develop a variation of this a few years later as a room sanitizer for hospitals.

Tesla theorized that the application of electricity to the brain enhanced intelligence. In 1912, he crafted “a plan to make dull students bright by saturating them unconsciously with electricity,” wiring the walls of a schoolroom and, “saturating [the schoolroom] with infinitesimal electric waves vibrating at high frequency. The whole room will thus, Mr. Tesla claims, be converted into a health-giving and stimulating electromagnetic field or ‘bath.'” The plan was, at least provisionally, approved by then superintendent of New York City schools, William H. Maxwell.

Before World War I, Tesla sought overseas investors. After the war started, Tesla lost the funding he was receiving from his patents in European countries.

In the August 1917 edition of the magazine Electrical Experimenter, Tesla postulated that electricity could be used to locate submarines via using the reflection of an “electric ray” of “tremendous frequency,” with the signal being viewed on a fluorescent screen (a system that has been noted to have a superficial resemblance to modern radar). Tesla was incorrect in his assumption that high frequency radio waves would penetrate water. Émile Girardeau, who helped develop France’s first radar system in the 1930s, noted in 1953 that Tesla’s general speculation that a very strong high-frequency signal would be needed was correct. Girardeau said, “(Tesla) was prophesying or dreaming, since he had at his disposal no means of carrying them out, but one must add that if he was dreaming, at least he was dreaming correctly.”

In 1928, Tesla received patent, U.S. Patent 1,655,114, for a biplane capable of taking off vertically (VTOL aircraft) and then of being “gradually tilted through manipulation of the elevator devices” in flight until it was flying like a conventional plane. Tesla thought the plane would sell for less than $1,000, although the aircraft has been described as impractical. This would be his last patent and at this time Tesla closed his last office at 350 Madison Ave., which he had moved into two years earlier.

Living Circumstances

Since 1900, Tesla had been living at the Waldorf Astoria in New York running up a large bill. In 1922, he moved to St. Regis Hotel and would follow a pattern from then on of moving to a new hotel every few years leaving behind unpaid bills.

Tesla would walk to the park every day to feed the pigeons. He took to feeding them at the window of his hotel room and bringing the injured ones in to nurse back to health. He said that he had been visited by a specific injured white pigeon daily. Tesla spent over $2,000, including building a device that comfortably supported her so her bones could heal, to fix her broken wing and leg. Tesla stated:

I have been feeding pigeons, thousands of them for years. But there was one, a beautiful bird, pure white with light grey tips on its wings; that one was different. It was a female. I had only to wish and call her and she would come flying to me. I loved that pigeon as a man loves a woman, and she loved me. As long as I had her, there was a purpose to my life.

Tesla’s unpaid bills, and complaints about the mess from his pigeon-feeding, forced him to leave the St. Regis in 1923, the Hotel Pennsylvania in 1930, and the Hotel Governor Clinton in 1934. At one point, he also took rooms at the Hotel Marguery.

In 1934, Tesla moved to the Hotel New Yorker and Westinghouse Electric & Manufacturing Company began paying him $125 per month as well as paying his rent, expenses the Company would pay for the rest of Tesla’s life. Accounts of how this came about vary. Several sources say Westinghouse was worried (or warned) about potential bad publicity surrounding the impoverished conditions under which their former star inventor was living. The payment has been described as being couched as a “consulting fee” to get around Tesla’s aversion to accept charity, or by one biographer (Marc Seifer), as a type of unspecified settlement.

Birthday Press Conferences

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Tesla on Time magazine commemorating his 75th birthday

In 1931, Kenneth Swezey, a young writer who had been associated with Tesla for some time, organized a celebration for the inventor’s 75th birthday. Tesla received congratulatory letters from more than 70 pioneers in science and engineering, including Albert Einstein, and he was also featured on the cover of Time magazine. The cover caption “All the world’s his power house” noted his contribution to electrical power generation. The party went so well Tesla made it an annual event, an occasion where he would put out a large spread of food and drink (featuring dishes of his own creation) and invite the press to see his inventions and hear stories about past exploits, views on current events, or sometimes odd or baffling claims.

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Newspaper representation of the thought camera Tesla described at his 1933 birthday party

At the 1932 occasion, Tesla claimed he had invented a motor that would run on cosmic rays. In 1933, at age 77, Tesla told reporters that, after thirty-five years of work, he was on the verge of producing proof of a new form of energy. He claimed it was a theory of energy that was “violently opposed” to Einsteinian physics, and could be tapped with an apparatus that would be cheap to run and last 500 years. He also told reporters he was working on a way to transmit individualized private radio wavelengths, working on breakthroughs in metallurgy, and developing a way to photograph the retina to record thought.

At the 1934 party, Tesla told reporters he had designed a superweapon he claimed would end all war. He would call it “teleforce”, but was usually referred to as his death ray. Tesla described it as a defensive weapon that would be put up along the border of a country to be used against attacking ground-based infantry or aircraft. Tesla never revealed detailed plans of how the weapon worked during his lifetime but in 1984, they surfaced at the Nikola Tesla Museum archive in Belgrade. The treatise, The New Art of Projecting Concentrated Non-dispersive Energy through the Natural Media, described an open-ended vacuum tube with a gas jet seal that allows particles to exit, a method of charging slugs of tungsten or mercury to millions of volts, and directing them in streams (through electrostatic repulsion). Tesla tried to interest the US War Department, the United Kingdom, the Soviet Union, and Yugoslavia in the device.

In 1935, at his 79th birthday party, Tesla covered many topics. He claimed to have discovered the cosmic ray in 1896 and invented a way to produce direct current by induction, and made many claims about his mechanical oscillator. Describing the device (which he expected would earn him $100 million within two years) he told reporters that a version of his oscillator had caused an earthquake in his 46 East Houston Street lab and neighboring streets in downtown New York City in 1898. He went on to tell reporters his oscillator could destroy the Empire State Building with 5 lbs of air pressure. He also explained a new technique he developed using his oscillators he called “Telegeodynamics”, using it to transmit vibrations into the ground that he claimed would work over any distance to be used for communication or locating underground mineral deposits.

At his 1937 celebration in the Grand Ballroom of Hotel New Yorker, Tesla received the “Order of the White Lion” from the Czechoslovakia ambassador and a medal from the Yugoslavian ambassador. On questions concerning the death ray, Tesla stated, “But it is not an experiment … I have built, demonstrated and used it. Only a little time will pass before I can give it to the world.”

In the fall of 1937, after midnight one night, Tesla left the Hotel New Yorker to make his regular commute to the cathedral and the library to feed the pigeons. While crossing a street a couple of blocks from the hotel, Tesla was unable to dodge a moving taxicab and was thrown to the ground. His back was severely wrenched and three of his ribs were broken in the accident. The full extent of his injuries were never known; Tesla refused to consult a doctor, an almost lifelong custom, and never fully recovered.

Death


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Gilded urn with Tesla’s ashes, in his favorite geometrical object, a sphere (Nikola Tesla Museum, Belgrade)

On 7 January 1943, at the age of 86, Tesla died alone in Room 3327 of the New Yorker Hotel. His body was later found by maid Alice Monaghan after she had entered Tesla’s room, ignoring the “do not disturb” sign that Tesla had placed on his door two days earlier. Assistant medical examiner H.W. Wembley examined the body and ruled that the cause of death had been coronary thrombosis.

Two days later the Federal Bureau of Investigation ordered the Alien Property Custodian to seize Tesla’s belongings, even though Tesla was an American citizen. John G. Trump, a professor at M.I.T. and a well-known electrical engineer serving as a technical aide to the National Defense Research Committee, was called in to analyze the Tesla items, which were being held in custody. After a three-day investigation, Trump’s report concluded that there was nothing which would constitute a hazard in unfriendly hands, stating:

[Tesla’s] thoughts and efforts during at least the past 15 years were primarily of a speculative, philosophical, and somewhat promotional character often concerned with the production and wireless transmission of power; but did not include new, sound, workable principles or methods for realizing such results.

In a box purported to contain a part of Tesla’s “death ray”, Trump found a 45-year-old multidecade resistance box.

On 10 January 1943 New York City mayor Fiorello La Guardia read a eulogy written by Slovene-American author Louis Adamic live over the WNYC radio while violin pieces “Ave Maria” and “Tamo daleko” were played in the background. On 12 January, two thousand people attended a state funeral for Tesla at the Cathedral of Saint John the Divine. After the funeral, Tesla’s body was taken to the Ferncliff Cemetery in Ardsley, New York, where it was later cremated. The following day, a second service was conducted by prominent priests in the Trinity Chapel (today’s Serbian Orthodox Cathedral of Saint Sava) in New York City.

Estate

In 1952, following pressure from Tesla’s nephew, Sava Kosanović, Tesla’s entire estate was shipped to Belgrade in 80 trunks marked N.T. In 1957, Kosanović’s secretary Charlotte Muzar transported Tesla’s ashes from the United States to Belgrade. The ashes are displayed in a gold-plated sphere on a marble pedestal in the Nikola Tesla Museum.

Patents


Tesla obtained around 300 patents worldwide for his inventions. Some of Tesla’s patents are not accounted for, and various sources have discovered some that have lain hidden in patent archives. There are a minimum of 278 known patents issued to Tesla in 26 countries. Many of Tesla’s patents were in the United States, Britain, and Canada, but many other patents were approved in countries around the globe. Many inventions developed by Tesla were not put into patent protection.

Personal Life


Tesla worked every day from 9:00 a.m. until 6:00 p.m. or later, with dinner from exactly 8:10 p.m., at Delmonico’s restaurant and later the Waldorf-Astoria Hotel. Tesla would telephone his dinner order to the headwaiter, who also could be the only one to serve him. “The meal was required to be ready at eight o’clock … He dined alone, except on the rare occasions when he would give a dinner to a group to meet his social obligations. Tesla would then resume his work, often until 3:00 a.m.”

For exercise, Tesla walked between 8 and 10 miles (13 and 16 km) per day. He curled his toes one hundred times for each foot every night, saying that it stimulated his brain cells.

In an interview with newspaper editor Arthur Brisbane, Tesla said that he did not believe in telepathy, stating, “Suppose I made up my mind to murder you,” he said, “In a second you would know it. Now, isn’t that wonderful? By what process does the mind get at all this?” In the same interview, Tesla said that he believed that all fundamental laws could be reduced to one.

Tesla became a vegetarian in his later years, living on only milk, bread, honey, and vegetable juices.

Appearance

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Tesla, aged 34, circa 1890. Photo by Napoleon Sarony

Tesla was 6 feet 2 inches (1.88 m) tall and weighed 142 pounds (64 kg), with almost no weight variance from 1888 to about 1926. His appearance was described by newspaper editor Arthur Brisbane as “almost the tallest, almost the thinnest and certainly the most serious man who goes to Delmonico’s regularly”. He was an elegant, stylish figure in New York City, meticulous in his grooming, clothing, and regimented in his daily activities, an appearance he maintained as to further his business relationships. He was also described as having light eyes, “very big hands”, and “remarkably big” thumbs.

Eidetic Memory

Tesla read many works, memorizing complete books, and supposedly possessed a photographic memory. He was a polyglot, speaking eight languages: Serbo-Croatian, Czech, English, French, German, Hungarian, Italian, and Latin. Tesla related in his autobiography that he experienced detailed moments of inspiration. During his early life, Tesla was repeatedly stricken with illness. He suffered a peculiar affliction in which blinding flashes of light would appear before his eyes, often accompanied by visions. Often, the visions were linked to a word or idea he might have come across; at other times they would provide the solution to a particular problem he had encountered. Just by hearing the name of an item, he would be able to envision it in realistic detail. Tesla would visualize an invention in his mind with extreme precision, including all dimensions, before moving to the construction stage, a technique sometimes known as picture thinking. He typically did not make drawings by hand but worked from memory. Beginning in his childhood, Tesla had frequent flashbacks to events that had happened previously in his life.

Sleep Habits

Tesla claimed never to sleep more than two hours per night. However, he did admit to “dozing” from time to time “to recharge his batteries.” During his second year of study at Graz, Tesla developed a passionate proficiency for billiards, chess, and card-playing, sometimes spending more than 48 hours in a stretch at a gaming table. On one occasion at his laboratory, Tesla worked for a period of 84 hours without rest. Kenneth Swezey, a journalist whom Tesla had befriended, confirmed that Tesla rarely slept. Swezey recalled one morning when Tesla called him at 3 a.m.: “I was sleeping in my room like one dead … Suddenly, the telephone ring awakened me … [Tesla] spoke animatedly, with pauses, [as he] … work[ed] out a problem, comparing one theory to another, commenting; and when he felt he had arrived at the solution, he suddenly closed the telephone.”

Relationships

Tesla never married, explaining that his chastity was very helpful to his scientific abilities. He once said in earlier years that he felt he could never be worthy enough for a woman, considering women superior in every way. His opinion had started to sway in later years when he felt that women were trying to outdo men and make themselves more dominant. This “new woman” was met with much indignation from Tesla, who felt that women were losing their femininity by trying to be in power. In an interview with the Galveston Daily News on 10 August 1924 he stated, “In place of the soft voiced, gentle woman of my reverent worship, has come the woman who thinks that her chief success in life lies in making herself as much as possible like man—in dress, voice and actions, in sports and achievements of every kind … The tendency of women to push aside man, supplanting the old spirit of cooperation with him in all the affairs of life, is very disappointing to me”.

 Although he told a reporter in later years that he sometimes felt that by not marrying, he had made too great a sacrifice to his work, Tesla chose to never pursue or engage in any known relationships, instead finding all the stimulation he needed in his work.

Tesla was asocial and prone to seclude himself with his work. However, when he did engage in a social life, many people spoke very positively and admiringly of Tesla. Robert Underwood Johnson described him as attaining a “distinguished sweetness, sincerity, modesty, refinement, generosity, and force.” His secretary, Dorothy Skerrit, wrote: “his genial smile and nobility of bearing always denoted the gentlemanly characteristics that were so ingrained in his soul.” Tesla’s friend, Julian Hawthorne, wrote, “seldom did one meet a scientist or engineer who was also a poet, a philosopher, an appreciator of fine music, a linguist, and a connoisseur of food and drink.”

Tesla was a good friend of Francis Marion Crawford, Robert Underwood Johnson, Stanford White, Fritz Lowenstein, George Scherff, and Kenneth Swezey. In middle age, Tesla became a close friend of Mark Twain; they spent a lot of time together in his lab and elsewhere. Twain notably described Tesla’s induction motor invention as “the most valuable patent since the telephone.” In the late 1920s, Tesla befriended George Sylvester Viereck, a poet, writer, mystic, and later, a Nazi propagandist. Tesla occasionally attended dinner parties held by Viereck and his wife.

Tesla could be harsh at times and openly expressed disgust for overweight people, such as when he fired a secretary because of her weight. He was quick to criticize clothing; on several occasions, Tesla directed a subordinate to go home and change her dress. When Thomas Edison died, in 1931, Tesla contributed the only negative opinion to The New York Times, buried in an extensive coverage of Edison’s life:

He had no hobby, cared for no sort of amusement of any kind and lived in utter disregard of the most elementary rules of hygiene … His method was inefficient in the extreme, for an immense ground had to be covered to get anything at all unless blind chance intervened and, at first, I was almost a sorry witness of his doings, knowing that just a little theory and calculation would have saved him 90 percent of the labor. But he had a veritable contempt for book learning and mathematical knowledge, trusting himself entirely to his inventor’s instinct and practical American sense.

Beliefs

On experimental and theoretical physics

Tesla exhibited a pre-atomic understanding of physics in his writings; he disagreed with the theory of atoms being composed of smaller subatomic particles, stating there was no such thing as an electron creating an electric charge. He believed that if electrons existed at all, they were some fourth state of matter or “sub-atom” that could exist only in an experimental vacuum and that they had nothing to do with electricity. Tesla believed that atoms are immutable—they could not change state or be split in any way. He was a believer in the 19th century concept of an all-pervasive “ether” that transmitted electrical energy.

Tesla was generally antagonistic towards theories about the conversion of matter into energy. He was also critical of Einstein’s theory of relativity, saying:

I hold that space cannot be curved, for the simple reason that it can have no properties. It might as well be said that God has properties. He has not, but only attributes and these are of our own making. Of properties we can only speak when dealing with matter filling the space. To say that in the presence of large bodies space becomes curved is equivalent to stating that something can act upon nothing. I, for one, refuse to subscribe to such a view.

Tesla claimed to have developed his own physical principle regarding matter and energy that he started working on in 1892, and in 1937, at age 81, claimed in a letter to have completed a “dynamic theory of gravity” that “[would] put an end to idle speculations and false conceptions, as that of curved space.” He stated that the theory was “worked out in all details” and that he hoped to soon give it to the world. Further elucidation of his theory was never found in his writings.

On Society

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Tesla circa 1885

Tesla is widely considered by his biographers to have been a humanist in philosophical outlook on top of his gifts as a technological scientist. This did not preclude Tesla, like many of his era, becoming a proponent of an imposed selective breeding version of eugenics.

Tesla expressed the belief that human “pity” had come to interfere with the natural “ruthless workings of nature.” Though his argumentation did not depend on a concept of a “master race” or the inherent superiority of one person over another, his advocacy of eugenics led him to adopt more extreme views. In a 1937 interview he stated:

… man’s new sense of pity began to interfere with the ruthless workings of nature. The only method compatible with our notions of civilization and the race is to prevent the breeding of the unfit by sterilization and the deliberate guidance of the mating instinct … The trend of opinion among eugenists is that we must make marriage more difficult. Certainly no one who is not a desirable parent should be permitted to produce progeny. A century from now it will no more occur to a normal person to mate with a person eugenically unfit than to marry a habitual criminal.

In 1926, Tesla commented on the ills of the social subservience of women and the struggle of women toward gender equality, and indicated that humanity’s future would be run by “Queen Bees.” He believed that women would become the dominant sex in the future.

Tesla made predictions about the relevant issues of a post-World War I environment in a printed article, “Science and Discovery are the great Forces which will lead to the Consummation of the War” (20 December 1914). Tesla believed that the League of Nations was not a remedy for the times and issues.

On Religion

Tesla was raised an Orthodox Christian. Later in life he did not consider himself to be a “believer in the orthodox sense,” said he opposed religious fanaticism, and said “Buddhism and Christianity are the greatest religions both in number of disciples and in importance”. He also said “To me, the universe is simply a great machine which never came into being and never will end” and “what we call ‘soul’ or ‘spirit,’ is nothing more than the sum of the functionings of the body. When this functioning ceases, the ‘soul’ or the ‘spirit’ ceases likewise”.

Literary Works


Tesla wrote a number of books and articles for magazines and journals. Among his books are My Inventions: The Autobiography of Nikola Tesla, compiled and edited by Ben Johnston; The Fantastic Inventions of Nikola Tesla, compiled and edited by David Hatcher Childress; and The Tesla Papers.

Many of Tesla’s writings are freely available online, including the article “The Problem of Increasing Human Energy,” published in The Century Magazine in 1900, and the article “Experiments With Alternate Currents Of High Potential And High Frequency,” published in his book Inventions, Researches and Writings of Nikola Tesla.

Legacy and honors


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Nikola Tesla Museum in Belgrade, Serbia

Tesla’s legacy has endured in books, films, radio, TV, music, live theater, comics, and video games. The impact of the technologies invented or envisioned by Tesla is a recurring theme in several types of science fiction.

Things named after Tesla

Awards

  • The Nikola Tesla Award

Enterprises and organizations

  • Tesla, an American rock band formed in Sacramento, California, in late 1982
  • Tesla, an electrotechnical conglomerate in the former Czechoslovakia
  • Tesla, Inc, an American electric car manufacturer
  • Ericsson Nikola Tesla, Croatian affiliate of the Swedish telecommunications equipment manufacturer Ericsson
  • The Tesla Society, founded in 1956
  • Udruženje za razvoj nauke Nikola Tesla, Novi Sad, Serbia
  • Zavičajno udruženje Krajišnika Nikola Tesla, Plandište, Serbia
  • Holidays and events

Day of Science, Serbia, 10 July

  • Day of Nikola Tesla, Association of Teachers in Vojvodina, 4–10 July
  • Day of Nikola Tesla, Niagara Falls, 10 July
  • Nikola Tesla Day in Croatia, 10 July
  • Nikola Tesla annual electric vehicle rally in Croatia

Measures

  • Tesla, an SI-derived unit of magnetic flux density (or magnetic inductivity)

Places

  • Belgrade Nikola Tesla Airport
  • Nikola Tesla Museum Archive in Belgrade
  • TPP Nikola Tesla, the largest power plant in Serbia
  • 128 streets in Croatia had been named after Nikola Tesla as of November 2008, making him the eighth most common street name origin in the country.
  • Tesla, a 26 kilometer-wide crater on the far side of the moon

2244 Tesla, a minor planet

Schools

  • Tesla STEM High School created in 2012 in Redmond, Washington as a choice school with a focus on STEM subjects. The name was chosen by a student vote.

Songs

  • “Tesla Girls”, a song by British pop band Orchestral Manoeuvres in the Dark, released in 1984

Ships

  • SS Nikola Tesla, a Liberty Ship laid down 31 August 1943, launched 25 September 1943, sold from government service in 1947, and scrapped 1970

Plaques and Memorials

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Nikola Tesla Corner in New York City

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Nikola Tesla statue in Niagara Falls, Ontario

The Nikola Tesla Memorial Centre in Smiljan, Croatia, opened in 2006. It features a statue of Tesla designed by sculptor Mile Blažević.

  • A plaque depicting a relief of Nikola Tesla is present on the Old City Hall (Zagreb) in Zagreb, Croatia’s capital, commemorating his proposal to build an alternating current power station, which he made to the city council. The plaque quotes Tesla’s statement, given in the building on 24 May 1892, which reads: “As a son of this country, I consider it my duty to help the City of Zagreb in every way, either through counsel or through action” (Croatian: “Smatram svojom dužnošću da kao rođeni sin svoje zemlje pomognem gradu Zagrebu u svakom pogledu savjetom i činom”).
  • On 7 July 2006, on the corner of Masarykova and Preradovićeva streets in the Lower Town area in Zagreb, a monument of Tesla was unveiled. This monument was designed by Ivan Meštrović in 1952 and was transferred from the Zagreb-based Ruđer Bošković Institute where it had spent previous decades.
  • A monument to Tesla was established at Niagara Falls, New York. This monument portraying Tesla reading a set of notes was sculpted by Frano Kršinić. It was presented to the United States by Yugoslavia in 1976 and is an identical copy of the monument standing in front of the University of Belgrade Faculty of Electrical Engineering.
  • A monument of Tesla standing on a portion of an alternator was established at Queen Victoria Park in Niagara Falls, Ontario, Canada. The monument was officially unveiled on 9 July 2006 on the 150th anniversary of Tesla’s birth. The monument was sponsored by St. George Serbian Church, Niagara Falls, and designed by Les Drysdale of Hamilton, Ontario. Drysdale’s design was the winning design from an international competition.
  • A monument of Tesla was unveiled in Baku in 2013. Presidents Ilham Aliyev and Tomislav Nikolić attended a ceremony of unveiling.
  • In 2012 Jane Alcorn, president of the nonprofit group Tesla Science Center at Wardenclyffe, and Matthew Inman, creator of web cartoon The Oatmeal, raised a total of $2,220,511 – $1,370,511 from a campaign and $850,000 from a New York State grant—to buy the property where Wardenclyffe Tower once stood and eventually turn it into a museum. The group began negotiations to purchase the Long Island property from Agfa Corporation in October 2012. The purchase was completed in May 2013. The preservation effort and history of Wardenclyffe is the subject of a documentary by Tesla activist/filmmaker Joseph Sikorski called “Tower to the People-Tesla’s Dream at Wardenclyffe Continues.”
  • A commemorative plaque honoring Nikola Tesla was installed on the façade of the New Yorker Hotel by the IEEE.
  • An intersection named after Tesla, Nikola Tesla Corner, is at the intersection of Sixth Avenue and 40th Street in Manhattan, New York City. The placement of the sign was due to the efforts of the Croatian Club of New York in cooperation with New York City officials, and Dr. Ljubo Vujovic of the Tesla Memorial Society of New York.
  • A bust and plaque honoring Tesla is outside the Serbian Orthodox Cathedral of Saint Sava (formerly known as Trinity Chapel) at 20 West 26th Street in New York City.
  • A full-size, crowdfunded statue honoring Tesla with free Wi-Fi and a time capsule (to be opened on the 100th anniversary of Tesla’s death, 7 January 2043) was unveiled on 7 December 2013 in Palo Alto, California (260 Sheridan Avenue).
  • Nikola Tesla Boulevard, Hamilton, Ontario.

Thomas Edison

From Wikipedia, the free encyclopedia

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Thomas Alva Edison (February 11, 1847 – October 18, 1931) was an American inventor and businessman, who has been described as America’s greatest inventor. He developed many devices that greatly influenced life around the world, including the phonograph, the motion picture camera, and the long-lasting, practical electric light bulb. Dubbed “The Wizard of Menlo Park”, he was one of the first inventors to apply the principles of mass production and large-scale teamwork to the process of invention, and because of that, he is often credited with the creation of the first industrial research laboratory.

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Edison was a prolific inventor, holding 1,093 US patents in his name, as well as many patents in the United Kingdom, France, and Germany. More significant than the number of Edison’s patents was the widespread impact of his inventions: electric light and power utilities, sound recording, and motion pictures all established major new industries worldwide. Edison’s inventions contributed to mass communication and, in particular, telecommunications. These included a stock ticker, a mechanical vote recorder, a battery for an electric car, electrical power, recorded music and motion pictures. His advanced work in these fields was an outgrowth of his early career as a telegraph operator. Edison developed a system of electric-power generation and distribution to homes, businesses, and factories – a crucial development in the modern industrialized world. His first power station was on Pearl Street in Manhattan, New York.

Early Life


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Edison as a boy

Thomas Edison was born in Milan, Ohio, and grew up in Port Huron, Michigan. He was the seventh and last child of Samuel Ogden Edison Jr. (1804–1896, born in Marshalltown, Nova Scotia) and Nancy Matthews Elliott (1810–1871, born in Chenango County, New York). His father, the son of a Loyalist refugee, had moved as a boy with the family from Nova Scotia, settling in southwestern Ontario (then called Upper Canada), in a village known as Shewsbury, later Vienna, by 1811. Samuel Jr. eventually fled Ontario, because he took part in the unsuccessful Mackenzie Rebellion of 1837. His father, Samuel Sr., had earlier fought in the War of 1812 as captain of the First Middlesex Regiment. By contrast, Samuel Jr.’s struggle found him on the losing side, and he crossed into the United States at Sarnia-Port Huron. Once across the border, he found his way to Milan, Ohio. His patrilineal family line was Dutch by way of New Jersey; the surname had originally been “Edeson.”

Edison only attended school for a few months and was instead taught by his mother. Much of his education came from reading R.G. Parker’s School of Natural Philosophy and The Cooper Union for the Advancement of Science and Art.

Edison developed hearing problems at an early age. The cause of his deafness has been attributed to a bout of scarlet fever during childhood and recurring untreated middle-ear infections. Around the middle of his career, Edison attributed the hearing impairment to being struck on the ears by a train conductor when his chemical laboratory in a boxcar caught fire and he was thrown off the train in Smiths Creek, Michigan, along with his apparatus and chemicals. In his later years, he modified the story to say the injury occurred when the conductor, in helping him onto a moving train, lifted him by the ears.

Edison’s family moved to Port Huron, Michigan, after the railroad bypassed Milan in 1854 and business declined. Edison sold candy and newspapers on trains running from Port Huron to Detroit, and sold vegetables. He briefly worked as a telegraph operator in 1863 for the Grand Trunk Railway at the railway station in Stratford, Ontario, at age 16. He was held responsible for a near collision. He also studied qualitative analysis and conducted chemical experiments on the train until he left the job.

Edison obtained the exclusive right to sell newspapers on the road, and, with the aid of four assistants, he set in type and printed the Grand Trunk Herald, which he sold with his other papers. This began Edison’s long streak of entrepreneurial ventures, as he discovered his talents as a businessman. These talents eventually led him to found 14 companies, including General Electric, still one of the largest publicly traded companies in the world.

Telegrapher


Edison became a telegraph operator after he saved three-year-old Jimmie MacKenzie from being struck by a runaway train. Jimmie’s father, station agent J. U. MacKenzie of Mount Clemens, Michigan, was so grateful that he trained Edison as a telegraph operator. Edison’s first telegraphy job away from Port Huron was at Stratford Junction, Ontario, on the Grand Trunk Railway.

In 1866, at the age of 19, Edison moved to Louisville, Kentucky, where, as an employee of Western Union, he worked the Associated Press bureau news wire. Edison requested the night shift, which allowed him plenty of time to spend at his two favorite pastimes—reading and experimenting. Eventually, the latter pre-occupation cost him his job. One night in 1867, he was working with a lead–acid battery when he spilled sulfuric acid onto the floor. It ran between the floorboards and onto his boss’s desk below. The next morning Edison was fired.

One of his mentors during those early years was a fellow telegrapher and inventor named Franklin Leonard Pope, who allowed the impoverished youth to live and work in the basement of his Elizabeth, New Jersey, home. Some of Edison’s earliest inventions were related to telegraphy, including a

 

stock ticker. His first patent was for the electric vote recorder, U.S. Patent 90,646, which was granted on June 1, 1869.

Marriages and Children


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Mina Miller Edison in 1906

On December 25, 1871, at the age of twenty-four, Edison married 16-year-old Mary Stilwell (1855–1884), whom he had met two months earlier; she was an employee at one of his shops. They had three children:

  • Marion Estelle Edison (1873–1965), nicknamed “Dot”
  • Thomas Alva Edison Jr. (1876–1935), nicknamed “Dash”
  • William Leslie Edison (1878–1937) Inventor, graduate of the Sheffield Scientific School at Yale, 1900.

Mary Edison died at age 29 on August 9, 1884, of unknown causes: possibly from a brain tumor or a morphine overdose. Doctors frequently prescribed morphine to women in those years to treat a variety of causes, and researchers believe that her symptoms could have been from morphine poisoning.

Edison generally preferred spending time in the laboratory to being with his family.

Mina Miller Edison in 1906

On February 24, 1886, at the age of thirty-nine, Edison married the 20-year-old Mina Miller (1865–1947) in Akron, Ohio. She was the daughter of the inventor Lewis Miller, co-founder of the Chautauqua Institution, and a benefactor of Methodist charities. They also had three children together:

  • Madeleine Edison (1888–1979), who married John Eyre Sloane.
  • Charles Edison (1890–1969), Governor of New Jersey (1941–1944), who took over his father’s company and experimental laboratories upon his father’s death.
  • Theodore Miller Edison (1898–1992), (MIT Physics 1923), credited with more than 80 patents.

Mina outlived Thomas Edison, dying on August 24, 1947.

Beginning his career


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Photograph of Edison with his phonograph (2nd model), taken in Mathew Brady’s Washington, DC studio in April 1878.

Edison began his career as an inventor in Newark, New Jersey, with the automatic repeater and his other improved telegraphic devices, but the invention that first gained him wider notice was the phonograph in 1877. This accomplishment was so unexpected by the public at large as to appear almost magical. Edison became known as “The Wizard of Menlo Park,” New Jersey.

His first phonograph recorded on tinfoil around a grooved cylinder. Despite its limited sound quality and that the recordings could be played only a few times, the phonograph made Edison a celebrity. Joseph Henry, president of the National Academy of Sciences and one of the most renowned electrical scientists in the US, described Edison as “the most ingenious inventor in this country… or in any other”. In April 1878, Edison traveled to Washington to demonstrate the phonograph before the National Academy of Sciences, Congressmen, Senators and US President Hayes. The Washington Post described Edison as a “genius” and his presentation as “a scene… that will live in history”. Although Edison obtained a patent for the phonograph in 1878, he did little to develop it until Alexander Graham Bell, Chichester Bell, and Charles Tainter produced a phonograph-like device in the 1880s that used wax-coated cardboard cylinders.

Menlo Park


Research and development facility

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Edison’s Menlo Park Laboratory, reconstructed at Greenfield Village at Henry Ford Museum in Dearborn, Michigan.

Edison’s major innovation was the establishment of an industrial research lab in 1876. It was built in Menlo Park, a part of Raritan Township, Middlesex County, New Jersey (today named Edison in his honor), with the funds from the sale of Edison’s quadruplex telegraph. After his demonstration of the telegraph, Edison was not sure that his original plan to sell it for $4,000 to $5,000 was right, so he asked Western Union to make a bid. He was surprised to hear them offer $10,000 ($216,300 in today’s dollars.), which he gratefully accepted.The quadruplex telegraph was Edison’s first big financial success, and Menlo Park became the first institution set up with the specific purpose of producing constant technological innovation and improvement. Edison was legally attributed with most of the inventions produced there, though many employees carried out research and development under his direction. His staff was generally told to carry out his directions in conducting research, and he drove them hard to produce results.

William Joseph Hammer, a consulting electrical engineer, started working for Edison and began his duties as a laboratory assistant in December 1879. He assisted in experiments on the telephone, phonograph, electric railway, iron ore separator, electric lighting, and other developing inventions. However, Hammer worked primarily on the incandescent electric lamp and was put in charge of tests and records on that device (see Hammer Historical Collection of Incandescent Electric Lamps). In 1880, he was appointed chief engineer of the Edison Lamp Works. In his first year, the plant under General Manager Francis Robbins Upton turned out 50,000 lamps. According to Edison, Hammer was “a pioneer of incandescent electric lighting”. Frank J. Sprague, a competent mathematician and former naval officer, was recruited by Edward H. Johnson and joined the Edison organization in 1883. One of Sprague’s contributions to the Edison Laboratory at Menlo Park was to expand Edison’s mathematical methods. Despite the common belief that Edison did not use mathematics, analysis of his notebooks reveal that he was an astute user of mathematical analysis conducted by his assistants such as Francis Robbins Upton, for example, determining the critical parameters of his electric lighting system including lamp resistance by an analysis of Ohm’s Law, Joule’s Law and economics.

Nearly all of Edison’s patents were utility patents, which were protected for a 17-year period and included inventions or processes that are electrical, mechanical, or chemical in nature. About a dozen were design patents, which protect an ornamental design for up to a 14-year period. As in most patents, the inventions he described were improvements over prior art. The phonograph patent, in contrast, was unprecedented as describing the first device to record and reproduce sounds.

In just over a decade, Edison’s Menlo Park laboratory had expanded to occupy two city blocks. Edison said he wanted the lab to have “a stock of almost every conceivable material”. A newspaper article printed in 1887 reveals the seriousness of his claim, stating the lab contained “eight thousand kinds of chemicals, every kind of screw made, every size of needle, every kind of cord or wire, hair of humans, horses, hogs, cows, rabbits, goats, minx, camels … silk in every texture, cocoons, various kinds of hoofs, shark’s teeth, deer horns, tortoise shell … cork, resin, varnish and oil, ostrich feathers, a peacock’s tail, jet, amber, rubber, all ores …” and the list goes on.

Over his desk, Edison displayed a placard with Sir Joshua Reynolds’ famous quotation: “There is no expedient to which a man will not resort to avoid the real labor of thinking.” This slogan was reputedly posted at several other locations throughout the facility.

With Menlo Park, Edison had created the first industrial laboratory concerned with creating knowledge and then controlling its application. Edison’s name is registered on 1,093 patents.

Carbon telephone transmitter

In 1876, Edison began work to improve the microphone for telephones (at that time called a “transmitter”) by developing a carbon microphone that used a button of carbon that would change resistance with the pressure of sound waves. Up to that point, microphones, such as the ones developed by Johann Philipp Reis and Alexander Graham Bell, worked by generating a weak current. Edison was one of many inventors working on the problem of creating a usable microphone for telephony by having it modulate an electrical current passed through it. His work was concurrent with Emile Berliner’s loose-contact carbon transmitter (who lost a later patent case against Edison over the carbon transmitters invention) and David Edward Hughes study and published paper on the physics of loose-contact carbon transmitters (work that Hughes did not bother to patent).

Edison used the carbon microphone concept in 1877 to create an improved telephone for Western Union. In 1886, Edison found a way to improve a Bell Telephone microphone, one that used loose-contact ground carbon, with his discovery that it worked far better if the carbon was roasted. This type was put in use in 1890 and was used in all telephones along with the Bell receiver until the 1980s.

Electric light

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Thomas Edison’s first successful light bulb model, used in public demonstration at Menlo Park, December 1879

In 1878, Edison began working on a system of electrical illumination, something he hoped could compete with gas and oil based lighting. He began by tackling the problem of creating a long-lasting incandescent lamp, something that would be needed for indoor use. Many earlier inventors had previously devised incandescent lamps, including Alessandro Volta’s demonstration of a glowing wire in 1800 and inventions by Henry Woodward and Mathew Evans. Others who developed early and commercially impractical incandescent electric lamps included Humphry Davy, James Bowman Lindsay, Moses G. Farmer, William E. Sawyer, Joseph Swan, and Heinrich Göbel. Some of these early bulbs had such flaws as an extremely short life, high expense to produce, and high electric current drawn, making them difficult to apply on a large scale commercially. Edison realized that to connect a series of electric lights to an economically manageable size and using the necessary thickness of copper wire, he would have to develop a lamp that used a low amount of current. This lamp must have high resistance and use relatively low voltage (around 110 volts).

After many experiments, first with carbon filaments and then with platinum and other metals, Edison returned to a carbon filament. The first successful test was on October 22, 1879; it lasted 13.5 hours. Edison continued to improve this design and on November 4, 1879, filed for U.S. patent 223,898 (granted on January 27, 1880) for an electric lamp using “a carbon filament or strip coiled and connected to platina contact wires”. This was the first commercially practical incandescent light.

Although the patent described several ways of creating the carbon filament including “cotton and linen thread, wood splints, papers coiled in various ways”, it was not until several months after the patent was granted that Edison and his team discovered a carbonized bamboo filament that could last over 1,200 hours. The idea of using this particular raw material originated from Edison’s recalling his examination of a few threads from a bamboo fishing pole while relaxing on the shore of Battle Lake in the present-day state of Wyoming, where he and other members of a scientific team had traveled so that they could clearly observe a total eclipse of the sun on July 29, 1878, from the Continental Divide.

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U.S. Patent#223898: Electric-Lamp. Issued January 27, 1880.

In 1878, Edison formed the Edison Electric Light Company in New York City with several financiers, including J. P. Morgan, Spencer Trask, and the members of the Vanderbilt family. Edison made the first public demonstration of his incandescent light bulb on December 31, 1879, in Menlo Park. It was during this time that he said: “We will make electricity so cheap that only the rich will burn candles.”

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The Oregon Railroad and Navigation Company’s new steamship, the Columbia, was the first commercial application for Edison’s incandescent light bulb in 1880.

Henry Villard, president of the Oregon Railroad and Navigation Company, attended Edison’s 1879 demonstration. Villard was impressed and requested Edison install his electric lighting system aboard Villard’s company’s new steamer, the Columbia. Although hesitant at first, Edison agreed to Villard’s request. Most of the work was completed in May 1880, and the Columbia went to New York City, where Edison and his personnel installed Columbia’s new lighting system. The Columbia was Edison’s first commercial application for his incandescent light bulb. The Edison equipment was removed from Columbia in 1895.

Lewis Latimer joined the Edison Electric Light Company in 1884. Latimer had received a patent in January 1881 for the “Process of Manufacturing Carbons”, an improved method for the production of carbon filaments for light bulbs. Latimer worked as an engineer, a draftsman and an expert witness in patent litigation on electric lights.

George Westinghouse’s company bought Philip Diehl’s competing induction lamp patent rights (1882) for $25,000, forcing the holders of the Edison patent to charge a more reasonable rate for the use of the Edison patent rights and lowering the price of the electric lamp.

On October 8, 1883, the US patent office ruled that Edison’s patent was based on the work of William E. Sawyer and was, therefore, invalid. Litigation continued for nearly six years, until October 6, 1889, when a judge ruled that Edison’s electric light improvement claim for “a filament of carbon of high resistance” was valid. To avoid a possible court battle with Joseph Swan, whose British patent had been awarded a year before Edison’s, he and Swan formed a joint company called Ediswan to manufacture and market the invention in Britain.

Mahen Theatre in Brno (in what is now the Czech Republic), opened in 1882, and was the first public building in the world to use Edison’s electric lamps. Francis Jehl, Edison’s assistant in the invention of the lamp, supervised the installation. In September 2010, a sculpture of three giant light bulbs was erected in Brno, in front of the theatre.

Electric Power Distribution


After devising a commercially viable electric light bulb on October 21, 1879, Edison developed an electric “utility” to compete with the existing gas light utilities. On December 17, 1880, he founded the Edison Illuminating Company, and during the 1880s, he patented a system for electricity distribution. The company established the first investor-owned electric utility in 1882 on Pearl Street Station, New York City. On September 4, 1882, Edison switched on his Pearl Street generating station’s electrical power distribution system, which provided 110 volts direct current (DC) to 59 customers in lower Manhattan.

In January 1882, Edison switched on the first steam-generating power station at Holborn Viaduct in London. The DC supply system provided electricity supplies to street lamps and several private dwellings within a short distance of the station. On January 19, 1883, the first standardized incandescent electric lighting system employing overhead wires began service in Roselle, New Jersey.

War of currents

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Extravagant displays of electric lights quickly became a feature of public events, as in this picture from the 1897 Tennessee Centennial Exposition.

As Edison expanded his direct current (DC) power delivery system, he received stiff competition from companies installing alternating current (AC) systems. From the early 1880s AC arc lighting systems for streets and large spaces had been an expanding business in the US. With the development of transformers in Europe and by Westinghouse Electric in the US in 1885–1886, it became possible to transmit AC long distances over thinner and cheaper wires, and “step down” the voltage at the destination for distribution to users. This allowed AC to be used in street lighting and in lighting for small business and domestic customers, the market Edison’s patented low voltage DC incandescent lamp system was designed to supply. Edison’s DC empire suffered from one of its chief drawbacks: it was suitable only for the high density of customers found in large cities. Edison’s DC plants could not deliver electricity to customers more than one mile from the plant, and left a patchwork of unsupplied customers between plants. Small cities and rural areas could not afford an Edison style system at all, leaving a large part of the market without electrical service. AC companies expanded into this gap.

Edison expressed views that AC was unworkable and the high voltages used were dangerous. As George Westinghouse installed his first AC systems in 1886, Thomas Edison struck out personally against his chief rival stating, “Just as certain as death, Westinghouse will kill a customer within six months after he puts in a system of any size. He has got a new thing and it will require a great deal of experimenting to get it working practically.” Many reasons have been suggested for Edison’s anti-AC stance. One notion is that the inventor could not grasp the more abstract theories behind AC and was trying to avoid developing a system he did not understand. Edison also appeared to have been worried about the high voltage from misinstalled AC systems killing customers and hurting the sales of electric power systems in general. Primary was the fact that Edison Electric based their design on low voltage DC and switching a standard after they had installed over 100 systems was, in Edison’s mind, out of the question. By the end of 1887, Edison Electric was losing market share to Westinghouse, who had built 68 AC-based power stations to Edison’s 121 DC-based stations. To make matters worse for Edison, the Thomson-Houston Electric Company of Lynn, Massachusetts (another AC-based competitor) built 22 power stations.

Parallel to expanding competition between Edison and the AC companies was rising public furor over a series of deaths in the spring of 1888 caused by pole mounted high voltage alternating current lines. This turned into a media frenzy against high voltage alternating current and the seemingly greedy and callous lighting companies that used it. Edison took advantage of the public perception of AC as dangerous, and joined with self-styled New York anti-AC crusader Harold P. Brown in a propaganda campaign, aiding Brown in the public electrocution of animals with AC, and supported legislation to control and severely limit AC installations and voltages (to the point of making it an ineffective power delivery system) in what was now being referred to as a “battle of currents”. The development of the electric chair was used in an attempt to portray AC as having a greater lethal potential than DC and smear Westinghouse at the same time via Edison colluding with Brown and Westinghouse’s chief AC rival, the Thomson-Houston Electric Company, to make sure the first electric chair was powered by a Westinghouse AC generator.

Thomas Edison’s staunch anti-AC tactics were not sitting well with his own stockholders. By the early 1890s, Edison’s company was generating much smaller profits than its AC rivals, and the War of Currents would come to an end in 1892 with Edison forced out of controlling his own company. That year, the financier J.P. Morgan engineered a merger of Edison General Electric with Thomson-Houston that put the board of Thomson-Houston in charge of the new company called General Electric. General Electric now controlled three-quarters of the US electrical business and would compete with Westinghouse for the AC market.

Other inventions and projects


Fluoroscopy

Edison is credited with designing and producing the first commercially available fluoroscope, a machine that uses X-rays to take radiographs. Until Edison discovered that calcium tungstate fluoroscopy screens produced brighter images than the barium platinocyanide screens originally used by Wilhelm Röntgen, the technology was capable of producing only very faint images.

The fundamental design of Edison’s fluoroscope is still in use today, although Edison abandoned the project after nearly losing his own eyesight and seriously injuring his assistant, Clarence Dally. Dally made himself an enthusiastic human guinea pig for the fluoroscopy project and was exposed to a poisonous dose of radiation. He later died of injuries related to the exposure. In 1903, a shaken Edison said: “Don’t talk to me about X-rays, I am afraid of them.”

Telegraph improvements

The key to Edison’s fortunes was telegraphy. With knowledge gained from years of working as a telegraph operator, he learned the basics of electricity. This allowed him to make his early fortune with the stock ticker, the first electricity-based broadcast system. On August 9, 1892, Edison received a patent for a two-way telegraph.

Motion pictures

The June 1894 Leonard–Cushing bout. Each of the six one-minute rounds recorded by the Kinetoscope was made available to exhibitors for $22.50. Customers who watched the final round saw Leonard score a knockdown.

Edison was also granted a patent for the motion picture camera or “Kinetograph”. He did the electromechanical design while his employee W. K. L. Dickson, a photographer, worked on the photographic and optical development. Much of the credit for the invention belongs to Dickson. In 1891, Thomas Edison built a Kinetoscope or peep-hole viewer. This device was installed in penny arcades, where people could watch short, simple films. The kinetograph and kinetoscope were both first publicly exhibited May 20, 1891.

In April 1896, Thomas Armat’s Vitascope, manufactured by the Edison factory and marketed in Edison’s name, was used to project motion pictures in public screenings in New York City. Later, he exhibited motion pictures with voice soundtrack on cylinder recordings, mechanically synchronized with the film.

Officially the kinetoscope entered Europe when the rich American Businessman Irving T. Bush (1869–1948) bought from the Continental Commerce Company of Frank Z. Maguire and Joseph D. Baucus a dozen machines. Bush placed from October 17, 1894, the first kinetoscopes in London. At the same time, the French company Kinétoscope Edison Michel et Alexis Werner bought these machines for the market in France. In the last three months of 1894, the Continental Commerce Company sold hundreds of kinetoscopes in Europe (i.e. the Netherlands and Italy). In Germany and in Austria-Hungary, the kinetoscope was introduced by the Deutsche-österreichische-Edison-Kinetoscop Gesellschaft, founded by the Ludwig Stollwerck of the Schokoladen-Süsswarenfabrik Stollwerck & Co of Cologne.

The first kinetoscopes arrived in Belgium at the Fairs in early 1895. The Edison’s Kinétoscope Français, a Belgian company, was founded in Brussels on January 15, 1895, with the rights to sell the kinetoscopes in Monaco, France and the French colonies. The main investors in this company were Belgian industrialists.

On May 14, 1895, the Edison’s Kinétoscope Belge was founded in Brussels. The businessman Ladislas-Victor Lewitzki, living in London but active in Belgium and France, took the initiative in starting this business. He had contacts with Leon Gaumont and the American Mutoscope and Biograph Co. In 1898, he also became a shareholder of the Biograph and Mutoscope Company for France.

Edison’s film studio made close to 1,200 films. The majority of the productions were short films showing everything from acrobats to parades to fire calls including titles such as Fred Ott’s Sneeze (1894), The Kiss (1896), The Great Train Robbery (1903), Alice’s Adventures in Wonderland (1910), and the first Frankenstein film in 1910. In 1903, when the owners of Luna Park, Coney Island announced they would execute Topsy the elephant by strangulation, poisoning, and electrocution (with the electrocution part ultimately killing the elephant), Edison Manufacturing sent a crew to film it, releasing it that same year with the title Electrocuting an Elephant.

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A Day with Thomas Edison (1922)

As the film business expanded, competing exhibitors routinely copied and exhibited each other’s films. To better protect the copyrights on his films, Edison deposited prints of them on long strips of photographic paper with the U.S. copyright office. Many of these paper prints survived longer and in better condition than the actual films of that era.

In 1908, Edison started the Motion Picture Patents Company, which was a conglomerate of nine major film studios (commonly known as the Edison Trust). Thomas Edison was the first honorary fellow of the Acoustical Society of America, which was founded in 1929.

Edison said his favorite movie was The Birth of a Nation. He thought that talkies had “spoiled everything” for him. “There isn’t any good acting on the screen. They concentrate on the voice now and have forgotten how to act. I can sense it more than you because I am deaf.” His favorite stars were Mary Pickford and Clara Bow.

Mining

Starting in the late 1870s, Thomas Edison became interested and involved with mining. High-grade iron ore was scarce on the east coast of the United States and Edison tried to mine low-grade ore. Edison developed a process using rollers and crushers that could pulverize rocks up to 10 tons. The dust was then sent between three giant magnets that would pull the iron ore from the dust. Despite the failure of his mining company, the Edison Ore Milling Company, Edison used some of the materials and equipment to produce cement.

In 1901, Edison visited an industrial exhibition in the Sudbury area in Ontario, Canada and thought nickel and cobalt deposits there could be used in his production of electrical equipment. He returned as a mining prospector and is credited with the original discovery of the Falconbridge ore body. His attempts to mine the ore body were not successful, and he abandoned his mining claim in 1903. A street in Falconbridge, as well as the Edison Building, which served as the head office of Falconbridge Mines, are named for him.

Battery

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Share of the Edison Storage Battery Company, issued 19. October 1903

The Edison Storage Battery Company was founded in 1901. With this company Edison exploited his invention of the accumulator. In 1904 already 450 people worked at the company. The first accumulators were produced for electric cars. But there were several defects. Several Customers were complaining about the products. When the capital of the company was spent Edison paid for the company with his private money. Not until 1910 Edison showed a mature product: A Nickel-Iron-Battery with Lye as liquid.

Rubber

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From left to right: Henry Ford, Thomas Edison, and Harvey Firestone, the three partners of the Edison Botanic Research Corporation.

Edison became concerned with America’s reliance on foreign supply of rubber and was determined to find a native supply of rubber. He joined Harvey Firestone and Henry Ford (each contributing $25,000) to create the Edison Botanic Research Corp. in 1927 and constructed a laboratory in Fort Myers, Florida the following year. Edison did the majority of the research and planting, sending results and sample rubber residues to his West Orange Lab. Edison employed a two-part Acid-base extraction, to derive latex from the plant material after it was dried and crushed to a powder. After testing 17,000 plant samples, he eventually found an adequate source in the Goldenrod plant.

West Orange and Fort Myers (1886–1931)

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Thomas A. Edison Industries Exhibit, Primary Battery section, 1915

Edison moved from Menlo Park after the death of his first wife, Mary, in 1884, and purchased a home known as “Glenmont” in 1886 as a wedding gift for his second wife, Mina, in Llewellyn Park in West Orange, New Jersey. In 1885, Thomas Edison bought property in Fort Myers, Florida, and built what was later called Seminole Lodge as a winter retreat. Edison and Mina spent many winters at their home in Fort Myers, and Edison tried to find a domestic source of natural rubber.

Due to the security concerns around World War I, Edison suggested forming a science and industry committee to provide advice and research to the US military, and he headed the Naval Consulting Board in 1915.

Edison’s work on rubber took place largely at his botanic research laboratory in Fort Myers, which has been designated as a National Historic Chemical Landmark. The laboratory was built after Thomas Edison, Henry Ford, and Harvey Firestone pulled together $75,000 to form the Edison Botanical Research Corporation. Initially, only Ford and Firestone were to contribute funds to the project while Edison did all the research. Edison, however, wished to contribute $25,000 as well. After testing over 17,000 plant species, Edison decided on Solidago leavenworthii, also known as Leavenworth’s Goldenrod. The plant, which normally grows roughly 3–4 feet tall with a 5% latex yield, was adapted by Edison through cross-breeding to produce plants twice the size and with a latex yield of 12%.

Thomas Edison Jr.’s activities

Wanting to be an inventor, but not having much of an aptitude for it, Thomas Edison’s son, Thomas Alva Edison Jr.. became a problem for his father and his father’s business. Starting in the 1890s, Thomas Jr. became involved in snake oil products and shady and fraudulent enterprises producing products being sold to the public as “The Latest Edison Discovery”. The situation became so bad that Thomas Sr. had to take his son to court to stop the practices, finally agreeing to pay Thomas Jr. an allowance of $35.00 (equivalent to $953 in 2017) per week, in exchange for not using the Edison name; the son began using aliases, such as Burton Willard. Thomas Jr., suffering from alcoholism, depression and ill health, worked at several menial jobs, but by 1931 (towards the end of his life) he would obtain a role in the Edison company, thanks to the intervention of his brother.

Final Years


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Henry Ford, Thomas Edison, and Harvey Firestone, respectively. Ft. Myers, Florida, February 11, 1929

Henry Ford, the automobile magnate, later lived a few hundred feet away from Edison at his winter retreat in Fort Myers. Ford once worked as an engineer for the Edison Illuminating Company of Detroit and met Edison at a convention of affiliated Edison illuminating companies in Brooklyn, NY in 1896. Edison was impressed with Ford’s internal combustion engine automobile and encouraged its developments. They were friends until Edison’s death. Edison and Ford undertook annual motor camping trips from 1914 to 1924. Harvey Firestone and John Burroughs also participated.

In 1928, Edison joined the Fort Myers Civitan Club. He believed strongly in the organization, writing that “The Civitan Club is doing things—big things—for the community, state, and nation, and I certainly consider it an honor to be numbered in its ranks.” He was an active member in the club until his death, sometimes bringing Henry Ford to the club’s meetings.

Edison was active in business right up to the end. Just months before his death, the Lackawanna Railroad inaugurated suburban electric train service from Hoboken to Montclair, Dover, and Gladstone, New Jersey. Electrical transmission for this service was by means of an overhead catenary system using direct current, which Edison had championed. Despite his frail condition, Edison was at the throttle of the first electric MU (Multiple-Unit) train to depart Lackawanna Terminal in Hoboken in September 1930, driving the train the first mile through Hoboken yard on its way to South Orange.

This fleet of cars would serve commuters in northern New Jersey for the next 54 years until their retirement in 1984. A plaque commemorating Edison’s inaugural ride can be seen today in the waiting room of Lackawanna Terminal in Hoboken, which is presently operated by New Jersey Transit.

Edison was said to have been influenced by a popular fad diet in his last few years; “the only liquid he consumed was a pint of milk every three hours”. He is reported to have believed this diet would restore his health. However, this tale is doubtful. In 1930, the year before Edison died, Mina said in an interview about him, “correct eating is one of his greatest hobbies.” She also said that during one of his periodic “great scientific adventures”, Edison would be up at 7:00, have breakfast at 8:00, and be rarely home for lunch or dinner, implying that he continued to have all three.

Edison became the owner of his Milan, Ohio, birthplace in 1906. On his last visit, in 1923, he was reportedly shocked to find his old home still lit by lamps and candles.

Death


Edison died of complications of diabetes on October 18, 1931, in his home, “Glenmont” in Llewellyn Park in West Orange, New Jersey, which he had purchased in 1886 as a wedding gift for Mina. He is buried behind the home.

Edison’s last breath is reportedly contained in a test tube at The Henry Ford museum near Detroit. Ford reportedly convinced Charles Edison to seal a test tube of air in the inventor’s room shortly after his death, as a memento. A plaster death mask and casts of Edison’s hands were also made. Mina died in 1947.

Views on politics, religion, and metaphysics


Historian Paul Israel has characterized Edison as a “freethinker”. Edison was heavily influenced by Thomas Paine’s The Age of Reason. Edison defended Paine’s “scientific deism”, saying, “He has been called an atheist, but atheist he was not. Paine believed in a supreme intelligence, as representing the idea which other men often express by the name of deity.” In an October 2, 1910, interview in the New York Times Magazine, Edison stated:

Nature is what we know. We do not know the gods of religions. And nature is not kind, or merciful, or loving. If God made me — the fabled God of the three qualities of which I spoke: mercy, kindness, love — He also made the fish I catch and eat. And where do His mercy, kindness, and love for that fish come in? No; nature made us — nature did it all — not the gods of the religions.

Edison was accused of being an atheist for those remarks, and although he did not allow himself to be drawn into the controversy publicly, he clarified himself in a private letter:

You have misunderstood the whole article, because you jumped to the conclusion that it denies the existence of God. There is no such denial, what you call God I call Nature, the Supreme intelligence that rules matter. All the article states is that it is doubtful in my opinion if our intelligence or soul or whatever one may call it lives hereafter as an entity or disperses back again from whence it came, scattered amongst the cells of which we are made.

He also stated, “I do not believe in the God of the theologians; but that there is a Supreme Intelligence I do not doubt.”

Nonviolence was key to Edison’s moral views, and when asked to serve as a naval consultant for World War I, he specified he would work only on defensive weapons and later noted, “I am proud of the fact that I never invented weapons to kill.” Edison’s philosophy of nonviolence extended to animals as well, about which he stated: “Nonviolence leads to the highest ethics, which is the goal of all evolution. Until we stop harming all other living beings, we are still savages.” He was a vegetarian but not a vegan in actual practice, at least near the end of his life.

In 1920, Edison set off a media sensation when he told B. C. Forbes of American Magazine that he was working on a “spirit phone” to allow communication with the dead, a story which other newspapers and magazines repeated. Edison later disclaimed the idea, telling the New York Times in 1926 that “I really had nothing to tell him, but I hated to disappoint him so I thought up this story about communicating with spirits, but it was all a joke.”

Views on money


Thomas Edison was an advocate for monetary reform in the United States. He was ardently opposed to the gold standard and debt-based money. Famously, he was quoted in the New York Times stating “Gold is a relic of Julius Caesar, and interest is an invention of Satan.”

In the same article, he expounded upon the absurdity of a monetary system in which the taxpayer of the United States, in need of a loan, can be compelled to pay in return perhaps double the principal, or even greater sums, due to interest. His basic point was that, if the Government can produce debt-based money, it could equally as well produce money that was a credit to the taxpayer.

He thought at length about the subject of money in 1921 and 1922. In May 1922, he published a proposal, entitled “A Proposed Amendment to the Federal Reserve Banking System”. In it, he detailed an explanation of a commodity-backed currency, in which the Federal Reserve would issue interest-free currency to farmers, based on the value of commodities they produced. During a publicity tour that he took with friend and fellow inventor, Henry Ford, he spoke publicly about his desire for monetary reform. For insight, he corresponded with prominent academic and banking professionals. In the end, however, Edison’s proposals failed to find support and were eventually abandoned.

Awards


Portrait of Edison by Abraham Archibald Anderson (1890), National Portrait Gallery

The President of the Third French Republic, Jules Grévy, on the recommendation of his Minister of Foreign Affairs, Jules Barthélemy-Saint-Hilaire, and with the presentations of the Minister of Posts and Telegraphs, Louis Cochery, designated Edison with the distinction of an Officer of the Legion of Honour (Légion d’honneur) by decree on November 10, 1881; Edison was also named a Chevalier in the Legion in 1879, and a Commander in 1889.

  • In 1887, Edison won the Matteucci Medal. In 1890, he was elected a member of the Royal Swedish Academy of Sciences.
  • The Philadelphia City Council named Edison the recipient of the John Scott Medal in 1889.
  • In 1899, Edison was awarded the Edward Longstreth Medal of The Franklin Institute.
  • He was named an Honorable Consulting Engineer at the Louisiana Purchase Exposition World’s fair in 1904.
  • In 1908, Edison received the American Association of Engineering Societies John Fritz Medal.
  • In 1915, Edison was awarded Franklin Medal of The Franklin Institute for discoveries contributing to the foundation of industries and the well-being of the human race.
  • In 1920, the United States Navy department awarded him the Navy Distinguished Service Medal.
  • In 1923, the American Institute of Electrical Engineers created the Edison Medal and he was its first recipient.
  • In 1927, he was granted membership in the National Academy of Sciences.
  • On May 29, 1928, Edison received the Congressional Gold Medal.
  • In 1983, the United States Congress, pursuant to Senate Joint Resolution 140 (Public Law 97—198), designated February 11, Edison’s birthday, as National Inventor’s Day.
  • Life magazine (USA), in a special double issue in 1997, placed Edison first in the list of the “100 Most Important People in the Last 1000 Years”, noting that the light bulb he promoted “lit up the world”. In the 2005 television series The Greatest American, he was voted by viewers as the fifteenth greatest.
  • In 2008, Edison was inducted in the New Jersey Hall of Fame.
  • In 2010, Edison was honored with a Technical Grammy Award.
  • In 2011, Edison was inducted into the Entrepreneur Walk of Fame and named a Great Floridian by the Florida Governor and Cabinet.

Tributes


Places and people named for Edison

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Thomas Edison commemorative stamp, issued on the 100th anniversary of his birth in 1947

Several places have been named after Edison, most notably the town of Edison, New Jersey. Thomas Edison State University, nationally known for adult learners, is in Trenton, New Jersey. Two community colleges are named for him: Edison State College (now Florida SouthWestern State College) in Fort Myers, Florida, and Edison Community College in Piqua, Ohio. There are numerous high schools named after Edison (see Edison High School) and other schools including Thomas A. Edison Middle School. Footballer Pelé’s father originally named him Edson, as a tribute to the inventor of the light bulb, but the name was incorrectly listed on his birth certificate as “Edison”.

The small town of Alva just east of Fort Myers took Edison’s middle name.

In 1883, the City Hotel in Sunbury, Pennsylvania was the first building to be lit with Edison’s three-wire system. The hotel was renamed The Hotel Edison upon Edison’s return to the city on 1922.

Lake Thomas A Edison in California was named after Edison to mark the 75th anniversary of the incandescent light bulb.

Edison was on hand to turn on the lights at the Hotel Edison in New York City when it opened in 1931.

Three bridges around the United States have been named in Edison’s honor: the Edison Bridge in New Jersey, the Edison Bridge in Florida, and the Edison Bridge in Ohio.

In space, his name is commemorated in asteroid 742 Edisona.

Museums and memorials

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Statue of young Thomas Edison by the railroad tracks in Port Huron, Michigan.

In West Orange, New Jersey, the 13.5 acres (5.5 hectares) Glenmont estate is maintained and operated by the National Park Service as the Edison National Historic Site, as is his nearby laboratory and workshops including the reconstructed “Black Maria”—the world’s first movie studio. The Thomas Alva Edison Memorial Tower and Museum is in the town of Edison, New Jersey. In Beaumont, Texas, there is an Edison Museum, though Edison never visited there. The Port Huron Museum, in Port Huron, Michigan, restored the original depot that Thomas Edison worked out of as a young news butcher. The depot has been named the Thomas Edison Depot Museum. The town has many Edison historical landmarks, including the graves of Edison’s parents, and a monument along the St. Clair River. Edison’s influence can be seen throughout this city of 32,000.

In Detroit, the Edison Memorial Fountain in Grand Circus Park was created to honor his achievements. The limestone fountain was dedicated October 21, 1929, the fiftieth anniversary of the creation of the lightbulb. On the same night, The Edison Institute was dedicated in nearby Dearborn.

He was inducted into the Automotive Hall of Fame in 1969.

A bronze statue of Edison was placed in the National Statuary Hall Collection at the United States Capitol in 2016, with the formal dedication ceremony held on September 20 of that year. The Edison statue replaced one of 19th-century state governor William Allen that had been one of Ohio’s two allowed contributions to the collection.

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Edison in 1915

Companies bearing Edison’s name

  • Edison General Electric, merged with Thomson-Houston Electric Company to form General Electric
  • Commonwealth Edison, now part of Exelon
  • Consolidated Edison
  • Edison International
  • Detroit Edison, a unit of DTE Energy
  • Edison S.p.A., a unit of Italenergia
  • Trade association the Edison Electric Institute, a lobbying and research group for investor-owned utilities in the United States
  • Edison Ore-Milling Company
  • Edison Portland Cement Company
  • Ohio Edison (merged with Centerior in 1997 to form First Energy)
  • Southern California Edison
  • Awards named in honor of Edison

The Edison Medal was created on February 11, 1904, by a group of Edison’s friends and associates. Four years later the American Institute of Electrical Engineers (AIEE), later IEEE, entered into an agreement with the group to present the medal as its highest award. The first medal was presented in 1909 to Elihu Thomson. It is the oldest award in the area of electrical and electronics engineering, and is presented annually “for a career of meritorious achievement in electrical science, electrical engineering or the electrical arts.”

In the Netherlands, the major music awards are named the Edison Award after him. The award is an annual Dutch music prize, awarded for outstanding achievements in the music industry, and is one of the oldest music awards in the world, having been presented since 1960.

The American Society of Mechanical Engineers concedes the Thomas A. Edison Patent Award to individual patents since 2000.

Other items named after Edison

The United States Navy named the USS Edison (DD-439), a Gleaves class destroyer, in his honor in 1940. The ship was decommissioned a few months after the end of World War II. In 1962, the Navy commissioned USS Thomas A. Edison (SSBN-610), a fleet ballistic missile nuclear-powered submarine.

In popular culture

Thomas Edison has appeared in popular culture as a character in novels, films, comics and video games. His prolific inventing helped make him an icon and he has made appearances in popular culture during his lifetime down to the present day. Edison is also portrayed in popular culture as an adversary of Nikola Tesla.

“Camping with Henry and Tom”, a fictional play based on Edison’s camping trips with Henry Ford, written by Mark St.Gemain. First presented at Lucille Lortel Theatre, New York, February 20, 1995.  

On February 11, 2011, on what would have been Thomas Edison’s 164th birthday, Google’s homepage featured an animated Google Doodle commemorating his many inventions. When the cursor was hovered over the doodle, a series of mechanisms seemed to move, causing a lightbulb to glow.

List of people who worked for Edison


The following is a list of people who worked for Thomas Edison in his laboratories at Menlo Park or West Orange or at the subsidiary electrical businesses that he supervised.

  • Edward Goodrich Acheson – chemist, worked at Menlo Park 1880–1884
  • William Symes Andrews – started at the Menlo Park machine shop 1879
  • Charles Batchelor – “chief experimental assistant”
  • John I. Beggs – manager of Edison Illuminating Company in New York, 1886
  • William Kennedy Dickson – joined Menlo Park in 1823, worked on the motion picture camera
  • Justus B. Entz – joined Edison Machine Works in 1887
  • Reginald Fessenden – worked at the Edison Machine Works in 1886
  • Henry Ford – engineer Edison Illuminating Company Detroit, Michigan, 1891–1899
  • William Joseph Hammer – started as laboratory assistant Menlo Park in 1879
  • Miller Reese Hutchison – inventor of hearing aid
  • Edward Hibberd Johnson – started in 1909, chief engineer at West Orange laboratory 1912–1918
  • Samuel Insull – started in 1881, rose to become VP of General Electric (1892) then President of Chicago Edison
  • Kunihiko Iwadare – joined Edison Machine Works in 1887
  • Francis Jehl – laboratory assistant Menlo Park 1879–1882
  • Arthur E. Kennelly – engineer, experimentalist at West Orange laboratory 1887–1894
  • John Kruesi – started 1872, was head machinist, at Newark, Menlo Park, Edison Machine Works
  • Lewis Howard Latimer – hired 1884 as a draftsman, continued working for General Electric
  • John W. Lieb – worked at the Edison Machine Works in 1881
  • Thomas Commerford Martin – electrical engineer, worked at Menlo Park 1877–1879
  • George F. Morrison – started at Edison Lamp Works 1882
  • Edwin Stanton Porter – joined the Edison Manufacturing Company 1899
  • Frank J. Sprague – Joined Menlo Park 1883, became known as the “Father of Electric Traction”.
  • Nikola Tesla – electrical engineer and inventor, worked at the Edison Machine Works in 1884
  • Francis Robbins Upton – mathematician/physicist, joined Menlo Park 1878

Telephone

From Wikipedia, the free encyclopedia

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A rotary dial telephone, c.1940s

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Modern telephones use push buttons

A telephone, or phone, is a telecommunications device that permits two or more users to conduct a conversation when they are too far apart to be heard directly. A telephone converts sound, typically and most efficiently the human voice, into electronic signals that are transmitted via cables and other communication channels to another telephone which reproduces the sound to the receiving user.

In 1876, Scottish emigrant Alexander Graham Bell was the first to be granted a United States patent for a device that produced clearly intelligible replication of the human voice. This instrument was further developed by many others. The telephone was the first device in history that enabled people to talk directly with each other across large distances. Telephones rapidly became indispensable to businesses, government, and households, and are today some of the most widely used small appliances.

The essential elements of a telephone are a microphone (transmitter) to speak into and an earphone (receiver) which reproduces the voice in a distant location. In addition, most telephones contain a ringer which produces a sound to announce an incoming telephone call, and a dial or keypad used to enter a telephone number when initiating a call to another telephone. Until approximately the 1970s most telephones used a rotary dial, which was superseded by the modern DTMF push-button dial, first introduced to the public by AT&T in 1963. The receiver and transmitter are usually built into a handset which is held up to the ear and mouth during conversation. The dial may be located either on the handset, or on a base unit to which the handset is connected. The transmitter converts the sound waves to electrical signals which are sent through a telephone network to the receiving telephone which converts the signals into audible sound in the receiver, or sometimes a loudspeaker. Telephones are duplex devices, meaning they permit transmission in both directions simultaneously.

The first telephones were directly connected to each other from one customer’s office or residence to another customer’s location. Being impractical beyond just a few customers, these systems were quickly replaced by manually operated centrally located switchboards. This gave rise to landline telephone service in which each telephone is connected by a pair of dedicated wires to a local central office switching system, which developed into fully automated systems starting in the early 1900s. For greater mobility, various radio systems were developed for transmission between mobile stations on ships and automobiles in the middle 20th century. Hand-held mobile phones were introduced for personal service starting in 1973. By the late 1970s several mobile telephone networks operated around the world. In 1983, the Advanced Mobile Phone System (AMPS) was launched, offering a standardized technology providing portability for users far beyond the personal residence or office. These analog cellular system evolved into digital networks with better security, greater capacity, better regional coverage, and lower cost. Today, the worldwide public switched telephone network, with its hierarchical system of many switching centers, can connect any telephone on the network with any other. With the standardized international numbering system, E.164, each telephone line has an identifying telephone number, that may be called from any other, authorized telephone on the network.

Although originally designed for simple voice communications, convergence has enabled most modern cell phones to have many additional capabilities. They may be able to record spoken messages, send and receive text messages, take and display photographs or video, play music or games, surf the Internet, do road navigation or immerse the user in virtual reality. Since 1999, the trend for mobile phones is smartphones that integrate all mobile communication and computing needs.

Basic Principles


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Schematic of a landline telephone installation.

A traditional landline telephone system, also known as plain old telephone service (POTS), commonly carries both control and audio signals on the same twisted pair (C in diagram) of insulated wires, the telephone line. The control and signaling equipment consists of three components, the ringer, the hookswitch, and a dial. The ringer, or beeper, light or other device (A7), alerts the user to incoming calls. The hookswitch signals to the central office that the user has picked up the handset to either answer a call or initiate a call. A dial, if present, is used by the subscriber to transmit a telephone number to the central office when initiating a call. Until the 1960s dials used almost exclusively the rotary technology, which was replaced by dual-tone multi-frequency signaling (DTMF) with pushbutton telephones (A4).

A major expense of wire-line telephone service is the outside wire plant. Telephones transmit both the incoming and outgoing speech signals on a single pair of wires. A twisted pair line rejects electromagnetic interference (EMI) and crosstalk better than a single wire or an untwisted pair. The strong outgoing speech signal from the microphone (transmitter) does not overpower the weaker incoming speaker (receiver) signal with sidetone because a hybrid coil (A3) and other components compensate the imbalance. The junction box (B) arrests lightning (B2) and adjusts the line’s resistance (B1) to maximize the signal power for the line length. Telephones have similar adjustments for inside line lengths (A8). The line voltages are negative compared to earth, to reduce galvanic corrosion. Negative voltage attracts positive metal ions toward the wires.

Details of Operation


The landline telephone contains a switchhook (A4) and an alerting device, usually a ringer (A7), that remains connected to the phone line whenever the phone is “on hook” (i.e. the switch (A4) is open), and other components which are connected when the phone is “off hook”. The off-hook components include a transmitter (microphone, A2), a receiver (speaker, A1), and other circuits for dialing, filtering (A3), and amplification.

A calling party wishing to speak to another party will pick up the telephone’s handset, thereby operating a lever which closes the switchhook (A4), which powers the telephone by connecting the transmitter (microphone), receiver (speaker), and related audio components to the line. The off-hook circuitry has a low resistance (less than 300 ohms) which causes a direct current (DC), which comes down the line (C) from the telephone exchange. The exchange detects this current, attaches a digit receiver circuit to the line, and sends a dial tone to indicate readiness. On a modern push-button telephone, the caller then presses the number keys to send the telephone number of the called party. The keys control a tone generator circuit (not shown) that makes DTMF tones that the exchange receives. A rotary-dial telephone uses pulse dialing, sending electrical pulses, that the exchange can count to get the telephone number (as of 2010 many exchanges were still equipped to handle pulse dialing). If the called party’s line is available, the exchange sends an intermittent ringing signal (about 75 volts alternating current (AC) in North America and UK and 60 volts in Germany) to alert the called party to an incoming call. If the called party’s line is in use, the exchange returns a busy signal to the calling party. However, if the called party’s line is in use but has call waiting installed, the exchange sends an intermittent audible tone to the called party to indicate an incoming call.

The ringer of a telephone (A7) is connected to the line through a capacitor (A6), which blocks direct current but passes the alternating current of the ringing signal. The telephone draws no current when it is on hook, while a DC voltage is continually applied to the line. Exchange circuitry (D2) can send an AC current down the line to activate the ringer and announce an incoming call. When there is no automatic exchange, telephones have hand-cranked magnetos to generate a ringing voltage back to the exchange or any other telephone on the same line. When a landline telephone is inactive (on hook), the circuitry at the telephone exchange detects the absence of direct current to indicate that the line is not in use. When a party initiates a call to this line, the exchange sends the ringing signal. When the called party picks up the handset, they actuate a double-circuit switchhook (not shown) which may simultaneously disconnects the alerting device and connects the audio circuitry to the line. This, in turn, draws direct current through the line, confirming that the called phone is now active. The exchange circuitry turns off the ring signal, and both telephones are now active and connected through the exchange. The parties may now converse as long as both phones remain off hook. When a party hangs up, placing the handset back on the cradle or hook, direct current ceases in that line, signaling the exchange to disconnect the call.

Calls to parties beyond the local exchange are carried over trunk lines which establish connections between exchanges. In modern telephone networks, fiber-optic cable and digital technology are often employed in such connections. Satellite technology may be used for communication over very long distances.

In most landline telephones, the transmitter and receiver (microphone and speaker) are located in the handset, although in a speakerphone these components may be located in the base or in a separate enclosure. Powered by the line, the microphone (A2) produces a modulated electric current which varies its frequency and amplitude in response to the sound waves arriving at its diaphragm. The resulting current is transmitted along the telephone line to the local exchange then on to the other phone (via the local exchange or via a larger network), where it passes through the coil of the receiver (A3). The varying current in the coil produces a corresponding movement of the receiver’s diaphragm, reproducing the original sound waves present at the transmitter.

Along with the microphone and speaker, additional circuitry is incorporated to prevent the incoming speaker signal and the outgoing microphone signal from interfering with each other. This is accomplished through a hybrid coil (A3). The incoming audio signal passes through a resistor (A8) and the primary winding of the coil (A3) which passes it to the speaker (A1). Since the current path A8 – A3 has a far lower impedance than the microphone (A2), virtually all of the incoming signal passes through it and bypasses the microphone.

At the same time the DC voltage across the line causes a DC current which is split between the resistor-coil (A8-A3) branch and the microphone-coil (A2-A3) branch. The DC current through the resistor-coil branch has no effect on the incoming audio signal. But the DC current passing through the microphone is turned into AC current (in response to voice sounds) which then passes through only the upper branch of the coil’s (A3) primary winding, which has far fewer turns than the lower primary winding. This causes a small portion of the microphone output to be fed back to the speaker, while the rest of the AC current goes out through the phone line.

A lineman’s handset is a telephone designed for testing the telephone network, and may be attached directly to aerial lines and other infrastructure components.

History


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Bell placing the first New York to Chicago telephone call in 1892

Before the development of the electric telephone, the term “telephone” was applied to other inventions, and not all early researchers of the electrical device called it “telephone”. A communication device for sailing vessels The Telephone was the invention of a captain John Taylor in 1844. This instrument used four air horns to communicate with vessels in foggy weather. Later, c. 1860, Johann Philipp Reis used the term in reference to his Reis telephone, his device appears to be the first such device based on conversion of sound into electrical impulses, the term telephone was adopted into the vocabulary of many languages. It is derived from the Greek: τῆλε, tēle, “far” and φωνή, phōnē, “voice”, together meaning “distant voice”.

Credit for the invention of the electric telephone is frequently disputed. As with other influential inventions such as radio, television, the light bulb, and the computer, several inventors pioneered experimental work on voice transmission over a wire and improved on each other’s ideas. New controversies over the issue still arise from time to time. Charles Bourseul, Antonio Meucci, Johann Philipp Reis, Alexander Graham Bell, and Elisha Gray, amongst others, have all been credited with the invention of the telephone.

Alexander Graham Bell was the first to be awarded a patent for the electric telephone by the United States Patent and Trademark Office (USPTO) in March 1876. The Bell patents were forensically victorious and commercially decisive. That first patent by Bell was the master patent of the telephone, from which other patents for electric telephone devices and features flowed.

In 1876, shortly after the telephone was invented, Hungarian engineer Tivadar Puskás invented the telephone switch, which allowed for the formation of telephone exchanges, and eventually networks.

Early Development

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Reis’ telephone

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Acoustic telephone ad, The Consolidated Telephone Co., Jersey City, NJ 1886

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1896 telephone from Sweden

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Wooden wall telephone with a hand-cranked magneto generator

  • 1844: Innocenzo Manzetti first mooted the idea of a “speaking telegraph” or telephone. Use of the “speaking telegraph” and “sound telegraph” monikers would eventually be replaced by the newer, distinct name, “telephone”.
  • 26 August 1854: Charles Bourseul published an article in the magazine L’Illustration (Paris): “Transmission électrique de la parole” (electric transmission of speech), describing a “make-and-break” type telephone transmitter later created by Johann Reis.
  • 26 October 1861: Johann Philipp Reis (1834–1874) publicly demonstrated the Reis telephone before the Physical Society of Frankfurt. Reis’ telephone was not limited to musical sounds. Reis also used his telephone to transmit the phrase “Das Pferd frisst keinen Gurkensalat” (“The horse does not eat cucumber salad”).
  • 22 August 1865, La Feuille d’Aoste reported “It is rumored that English technicians to whom Mr. Manzetti illustrated his method for transmitting spoken words on the telegraph wire intend to apply said invention in England on several private telegraph lines”. However telephones would not be demonstrated there until 1876, with a set of telephones from Bell.
  • 28 December 1871: Antonio Meucci files patent caveat No. 3335 in the U.S. Patent Office titled “Sound Telegraph”, describing communication of voice between two people by wire. A ‘patent caveat’ was not an invention patent award, but only an unverified notice filed by an individual that he or she intends to file a regular patent application in the future.
  • 1874: Meucci, after having renewed the caveat for two years does not renew it again, and the caveat lapses.
  • 6 April 1875: Bell’s U.S. Patent 161,739 “Transmitters and Receivers for Electric Telegraphs” is granted. This uses multiple vibrating steel reeds in make-break circuits.
  • 11 February 1876: Gray invents a liquid transmitter for use with a telephone but does not build one.
  • 14 February 1876: Elisha Gray files a patent caveat for transmitting the human voice through a telegraphic circuit.
  • 14 February 1876: Alexander Graham Bell applies for the patent “Improvements in Telegraphy”, for electromagnetic telephones using what is now called amplitude modulation (oscillating current and voltage) but which he referred to as “undulating current”.
  • 19 February 1876: Gray is notified by the U.S. Patent Office of an interference between his caveat and Bell’s patent application. Gray decides to abandon his caveat.
  • 7 March 1876: Bell’s U.S. patent 174,465 “Improvement in Telegraphy” is granted, covering “the method of, and apparatus for, transmitting vocal or other sounds telegraphically…by causing electrical undulations, similar in form to the vibrations of the air accompanying the said vocal or other sound.”
  • 10 March 1876: The first successful telephone transmission of clear speech using a liquid transmitter when Bell spoke into his device, “Mr. Watson, come here, I want to see you.” and Watson heard each word distinctly.
  • 30 January 1877: Bell’s U.S. patent 186,787 is granted for an electromagnetic telephone using permanent magnets, iron diaphragms, and a call bell.
  • 27 April 1877: Edison files for a patent on a carbon (graphite) transmitter. The patent 474,230 was granted 3 May 1892, after a 15-year delay because of litigation. Edison was granted patent 222,390 for a carbon granules transmitter in 1879.

Early commercial Instruments

Early telephones were technically diverse. Some used a water microphone, some had a metal diaphragm that induced current in an electromagnet wound around a permanent magnet, and some were dynamic – their diaphragm vibrated a coil of wire in the field of a permanent magnet or the coil vibrated the diaphragm. The sound-powered dynamic variants survived in small numbers through the 20th century in military and maritime applications, where its ability to create its own electrical power was crucial. Most, however, used the Edison/Berliner carbon transmitter, which was much louder than the other kinds, even though it required an induction coil which was an impedance matching transformer to make it compatible with the impedance of the line. The Edison patents kept the Bell monopoly viable into the 20th century, by which time the network was more important than the instrument.

Early telephones were locally powered, using either a dynamic transmitter or by the powering of a transmitter with a local battery. One of the jobs of outside plant personnel was to visit each telephone periodically to inspect the battery. During the 20th century, telephones powered from the telephone exchange over the same wires that carried the voice signals became common.

Early telephones used a single wire for the subscriber’s line, with ground return used to complete the circuit (as used in telegraphs). The earliest dynamic telephones also had only one port opening for sound, with the user alternately listening and speaking (or rather, shouting) into the same hole. Sometimes the instruments were operated in pairs at each end, making conversation more convenient but also more expensive.

At first, the benefits of a telephone exchange were not exploited. Instead telephones were leased in pairs to a subscriber, who had to arrange for a telegraph contractor to construct a line between them, for example between a home and a shop. Users who wanted the ability to speak to several different locations would need to obtain and set up three or four pairs of telephones. Western Union, already using telegraph exchanges, quickly extended the principle to its telephones in New York City and San Francisco, and Bell was not slow in appreciating the potential.

Signalling began in an appropriately primitive manner. The user alerted the other end, or the exchange operator, by whistling into the transmitter. Exchange operation soon resulted in telephones being equipped with a bell in a ringer box, first operated over a second wire, and later over the same wire, but with a condenser (capacitor) in series with the bell coil to allow the AC ringer signal through while still blocking DC (keeping the phone “on hook”). Telephones connected to the earliest Strowger switch automatic exchanges had seven wires, one for the knife switch, one for each telegraph key, one for the bell, one for the push-button and two for speaking. Large wall telephones in the early 20th century usually incorporated the bell, and separate bell boxes for desk phones dwindled away in the middle of the century.

Rural and other telephones that were not on a common battery exchange had a magneto hand-cranked generator to produce a high voltage alternating signal to ring the bells of other telephones on the line and to alert the operator. Some local farming communities that were not connected to the main networks set up barbed wire telephone lines that exploited the existing system of field fences to transmit the signal.

In the 1890s a new smaller style of telephone was introduced, packaged in three parts. The transmitter stood on a stand, known as a “candlestick” for its shape. When not in use, the receiver hung on a hook with a switch in it, known as a “switchhook”. Previous telephones required the user to operate a separate switch to connect either the voice or the bell. With the new kind, the user was less likely to leave the phone “off the hook”. In phones connected to magneto exchanges, the bell, induction coil, battery and magneto were in a separate bell box or “ringer box”. In phones connected to common battery exchanges, the ringer box was installed under a desk, or other out of the way place, since it did not need a battery or magneto.

Cradle designs were also used at this time, having a handle with the receiver and transmitter attached, now called a handset, separate from the cradle base that housed the magneto crank and other parts. They were larger than the “candlestick” and more popular.

Disadvantages of single wire operation such as crosstalk and hum from nearby AC power wires had already led to the use of twisted pairs and, for long distance telephones, four-wire circuits. Users at the beginning of the 20th century did not place long distance calls from their own telephones but made an appointment to use a special soundproofed long distance telephone booth furnished with the latest technology.

What turned out to be the most popular and longest lasting physical style of telephone was introduced in the early 20th century, including Bell’s 202-type desk set. A carbon granule transmitter and electromagnetic receiver were united in a single molded plastic handle, which when not in use sat in a cradle in the base unit. The circuit diagram of the model 202 shows the direct connection of the transmitter to the line, while the receiver was induction coupled. In local battery configurations, when the local loop was too long to provide sufficient current from the exchange, the transmitter was powered by a local battery and inductively coupled, while the receiver was included in the local loop. The coupling transformer and the ringer were mounted in a separate enclosure, called the subscriber set. The dial switch in the base interrupted the line current by repeatedly but very briefly disconnecting the line 1 to 10 times for each digit, and the hook switch (in the center of the circuit diagram) disconnected the line and the transmitter battery while the handset was on the cradle.

In the 1930s, telephone sets were developed that combined the bell and induction coil with the desk set, obviating a separate ringer box. The rotary dial becoming commonplace in the 1930s in many areas enabled customer-dialed service, but some magneto systems remained even into the 1960s. After World-War II, the telephone networks saw rapid expansion and more efficient telephone sets, such as the model 500 telephone in the United States, were developed that permitted larger local networks centered around central offices. A breakthrough new technology was the introduction of Touch-Tone signaling using push-button telephones by American Telephone & Telegraph Company (AT&T) in 1963.

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Ericsson DBH 1001 (ca. 1931), the first combined telephone made with a Bakelite housing and handset.

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Telephone used by American soldiers (WWII, Minalin, Pampanga, Philippines)

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Video shows the operation of an Ericofon

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AT&T push button telephone made by Western Electric model 2500 DMG black 1980

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A candlestick phone

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Modern sound-powered emergency telephone

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A mobile phone, also called a cell phone

Digital telephones and voice over IP


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An IP desktop telephone attached to a computer network, with touch-tone dialing

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Fixed telephone lines per 100 inhabitants 1997–2007

The invention of the transistor in 1947 dramatically changed the technology used in telephone systems and in the long-distance transmission networks. With the development of electronic switching systems in the 1960s, telephony gradually evolved towards digital telephony which improved the capacity, quality, and cost of the network.

The development of digital data communications method, such as the protocols used for the Internet, it became possible to digitize voice and transmit it as real-time data across computer networks, giving rise to the field of Internet Protocol (IP) telephony, also known as voice over Internet Protocol (VoIP), a term that reflects the methodology memorably. VoIP has proven to be a disruptive technology that is rapidly replacing traditional telephone network infrastructure.

As of January 2005, up to 10% of telephone subscribers in Japan and South Korea have switched to this digital telephone service. A January 2005 Newsweek article suggested that Internet telephony may be “the next big thing.” As of 2006 many VoIP companies offer service to consumers and businesses.

From a customer perspective, IP telephony uses a high-bandwidth Internet connection and specialized customer premises equipment to transmit telephone calls via the Internet, or any modern private data network. The customer equipment may be an analog telephone adapter (ATA) which interfaces a conventional analog telephone to the IP networking equipment, or it may be an IP Phone that has the networking and interface technology built into the desk-top set and provides the traditional, familiar parts of a telephone, the handset, the dial or keypad, and a ringer in a package that usually resembles a standard telephone set.

In addition, many computer software vendors and telephony operators provide softphone application software that emulates a telephone by use of an attached microphone and audio headset, or loud speaker.

Despite the new features and conveniences of IP telephones, some may have notable disadvantages compared to traditional telephones. Unless the IP telephone’s components are backed up with an uninterruptible power supply or other emergency power source, the phone ceases to function during a power outage as can occur during an emergency or disaster when the phone is most needed. Traditional phones connected to the older PSTN network do not experience that problem since they are powered by the telephone company’s battery supply, which will continue to function even if there is a prolonged power outage. Another problem in Internet-based services is the lack of a fixed physical location, impacting the provisioning of emergency services such as police, fire or ambulance, should someone call for them. Unless the registered user updates the IP phone’s physical address location after moving to a new residence, emergency services can be, and have been, dispatched to the wrong location.

Symbols

Graphic symbols used to designate telephone service or phone-related information in print, signage, and other media include ℡ (U+2121), ☎ (U+260E), ☏ (U+260F), ✆ (U+2706), and ⌕ (U+2315).

Use

In 2002, only 10% of the world’s population used cell phones and by 2005 that percentage had risen to 46%.  By the end of 2009, there were a total of nearly 6 billion mobile and fixed-line telephone subscribers worldwide. This included 1.26 billion fixed-line subscribers and 4.6 billion mobile subscribers.

Patents


  • “US 174,465”. pdfpiw.uspto.gov.—Telegraphy (Bell’s first telephone patent)—Alexander Graham Bell
  • US 186,787—Electric Telegraphy (permanent magnet receiver)—Alexander Graham Bell
  • US 474,230—Speaking Telegraph (graphite transmitter)—Thomas Edison
  • US 203,016—Speaking Telephone (carbon button transmitter)—Thomas Edison
  • US 222,390—Carbon Telephone (carbon granules transmitter)—Thomas Edison
  • US 485,311—Telephone (solid back carbon transmitter)—Anthony C. White (Bell engineer) This design was used until 1925 and installed phones were used until the 1940s.
  • US 3,449,750—Duplex Radio Communication and Signalling Appartus—G. H. Sweigert
  • US 3,663,762—Cellular Mobile Communication System—Amos Edward Joel (Bell Labs)
  • US 3,906,166—Radio Telephone System (DynaTAC cell phone)—Martin Cooper et al. (Motorola)

Urinary Catheterization

From Wikipedia, the free encyclopedia

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In urinary catheterization a latex, polyurethane, or silicone tube known as a urinary catheter is inserted into a patient’s bladder via the urethra. Catheterization allows the patient’s urine to drain freely from the bladder for collection. It may be used to inject liquids used for treatment or diagnosis of bladder conditions. A clinician, often a nurse, usually performs the procedure, but self-catheterization is also possible. The catheter may be a permanent one (indwelling catheter), or an intermittent catheter removed after each catheterization.

Catheter Types


Catheters come in several basic designs:

  • A Foley catheter (indwelling urinary catheter) is retained by means of a balloon at the tip that is inflated with sterile water. The balloons typically come in two different sizes: 5 cm3 and 30 cm3. They are commonly made in silicone rubber or natural rubber.
  • An intermittent catheter/Robinson catheter is a flexible catheter used for short term drainage of urine. Unlike the Foley catheter, it has no balloon on its tip and therefore cannot stay in place unaided. These can be non-coated or coated (e.g., hydrophilic coated and ready to use).
  • Intermittent self catheterization in males is best performed with a flexible catheter to drain the bladder periodically. The procedure should not be attempted by a patient without guidance in maintaining cleanliness of the catheter and surrounding area and specific instruction regarding catheter insertion from meatus to bladder entry.
  • A coudé catheter, including Tiemann’s catheter, is designed with a curved tip that makes it easier to pass through the curvature of the prostatic urethra.
  • A hematuria (or haematuria) catheter is a type of Foley catheter used for Post-TURP hemostasis. This is useful following endoscopic surgical procedures, or in the case of gross hematuria. There are both two-way and three-way hematuria catheters (double and triple lumen).
  • An condom catheter is used for incontinent males and carries a lower risk of infection than an indwelling catheter.
  • Catheter diameters are sized by the French catheter scale (F). The most common sizes are 10 F (3.3mm) to 28 F (9.3mm). The clinician selects a size large enough to allow free flow of urine, and large enough to control leakage of urine around the catheter. A larger size is necessary when the urine is thick, bloody, or contains large amounts of sediment. Larger catheters, however, are more likely to damage the urethra. Some people develop allergies or sensitivities to latex after long-term latex catheter use making it necessary to use silicone or Teflon types.

Evidence does not support an important decrease in the risk of urinary tract infections when silver-alloy catheters are used.

Sex Differences


In males, the catheter tube is inserted into the urinary tract through the penis. A condom-type catheter (also known as a ‘Texas catheter’), if used, fits around the tip of the penis, rather than being inserted. In females, the catheter is inserted into the urethral meatus, after a cleansing using povidone-iodine. The procedure can be complicated in females due to varying layouts of the genitalia (due to age, obesity, female genital cutting, childbirth, or other factors), but a good clinician would rely on anatomical landmarks and patience when dealing with such a patient. In the UK it is generally accepted that cleaning the area surrounding the urethral meatus with 0.9% sodium chloride solution is sufficient for both male and female patients as there is no reliable evidence to suggest that the use of antiseptic agents reduces the risk of urinary tract infection.

Males may have a slightly higher incidence of bladder spasms. If bladder spasms occur, or there is no urine in the drainage bag, the catheter may be blocked by blood, thick sediment, or a kink in the catheter or drainage tubing. Sometimes spasms are caused by the catheter irritating the bladder, prostate, or penis. Such spasms can be controlled with medication such as butylscopolamine, although most patients eventually adjust to the irritation and the spasms go away.

Common indications to catheterize a patient include acute or chronic urinary retention (which can damage the kidneys), orthopedic procedures that may limit a patient’s movement, the need for accurate monitoring of input and output (such as in an ICU), benign prostatic hyperplasia, incontinence, and the effects of various surgical interventions involving the bladder and prostate.

For some patients the insertion and removal of a catheter causes excruciating pain, so a topical anesthetic is used. Catheterization would be performed as a sterile medical procedure by trained, qualified personnel, using equipment designed for this purpose, except in the case of intermittent self-catheterization where patients have been trained to perform the procedure themselves.

Intermittent self-catheterization is performed by the patient four to six times a day, using a clean technique in most cases. Nurses use a sterile technique to perform intermittent catheterization in hospital settings. Incorrect technique may cause trauma to the urethra or prostate (male), urinary tract infection, or a paraphimosis in the uncircumcised male. For patients with spinal cord lesions and neurogenic bladder dysfunction, intermittent catheterisation (IC) is a standard method for bladder emptying. The technique is safe and effective and results in improved kidney and upper urinary tract status, lessening of vesicoureteral reflux and amelioration of continence. In addition to the clinical benefits, patient quality of life is enhanced by the increased independence and security offered by self-catheterization.

Illustrations

Foley_Catheter

Foley catheter

Condom_Catheter

Condom catheter

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Male Self-Catheterization

Female_Self-Catheterization

Female Self-Catheterization

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Male foley catheter

Catheter Maintenance


A catheter that is left in place for more than a short period of time is generally attached to a drainage bag to collect the urine. This also allows for measurement of urine volume. There are three types of drainage bags: The first is a leg bag, a smaller drainage device that attaches by elastic bands to the leg. A leg bag is usually worn during the day, as it fits discreetly under pants or skirts, and is easily emptied into a toilet. The second type of drainage bag is a larger device called a down drain that may be used overnight. This device is hung on a hook under the patient’s bed—never placed on the floor, due to risk of bacterial infection. The third is called a belly bag, and is secured around the waist. This bag can be worn at all times. It can be worn under the patient’s underwear to provide a totally undetectable look.

During long-term use, the catheter may be left in place all the time, or a patient may be instructed on a procedure for placing a catheter just long enough to empty the bladder and then removing it (known as intermittent self-catheterization). Patients undergoing major surgery are often catheterized and may remain so for some time. The patient may require irrigation of the bladder with sterile saline injected through the catheter to flush out clots or other matter that does not drain.

Maintenance

Condom_Cather_Drainage

How to properly drain a condom catheter.

Foley_Catheter_Drainage

How to properly drain a Foley catheter.

Closed_Urinary_Drainage

Illustration of a closed urinary drainage method.

Empty_the_Urinary_Drainage_Bag

Illustration of how to empty a urinary drainage bag.

Effects of long term use


The duration of catheterization can have significance. Incontinent patients commonly are catheterized to reduce their cost of care. However, long-term catheterization carries a significant risk of urinary tract infection.   Because of this risk catheterization is a last resort for the management of incontinence where other measures have proved unsuccessful. Other long term complications may include blood infections (sepsis), urethral injury, skin breakdown, bladder stones, and blood in the urine (hematuria). After many years of catheter use, bladder cancer may also develop.

Preventing infection


Everyday care of catheter and drainage bag is important to reduce the risk of infection. Such precautions include:

  • Cleansing the urethral area (area where catheter exits body) and the catheter itself.
  • Disconnecting drainage bag from catheter only with clean hands
  • Disconnecting drainage bag as seldom as possible.
  • Keeping drainage bag connector as clean as possible and cleansing the drainage bag periodically.
  • Use of a thin catheter where possible to reduce risk of harming the urethra during insertion.
  • Drinking sufficient liquid to produce at least two liters of urine daily
  • Sexual activity is very high risk for urinary infections, especially for catheterized women.
  • There is no clear evidence that any one catheter type or insertion technique is superior than another in preventing infection.

Recent developments in the field of the temporary prostatic stent have been viewed as a possible alternative to indwelling catheterization and the infections associated with their use.

Bifocals

From Wikipedia, the free encyclopedia

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Bifocals are eyeglasses with two distinct optical powers. Bifocals are commonly prescribed to people with presbyopia who also require a correction for myopia, hyperopia, and/or astigmatism.

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Bifocals with separate lenses

History


Benjamin Franklin is generally credited with the invention of bifocals. Historians have produced some evidence to suggest that others may have come before him in the invention; however, a correspondence between George Whatley and John Fenno, editor of The Gazette of the United States, suggested that Franklin had indeed invented bifocals, and perhaps 50 years earlier than had been originally thought. Since many inventions are developed independently by more than one person, it is possible that the invention of bifocals may have been such a case. Nonetheless, Benjamin Franklin was among the first to wear bifocal lenses, and Franklin’s letters of correspondence suggest that he invented them independently, regardless of whether he was the first to invent them.

John Isaac Hawkins, the inventor of trifocal lenses, coined the term bifocals in 1824 and credited Dr. Franklin.

In 1955, Irving Rips of Younger Optics created the first seamless or “invisible” bifocal, a precursor to all progressive lenses.

Construction

Original bifocals were designed with the most convex lenses (for close viewing) in the lower half of the frame and the least convex lenses on the upper. Up until the beginning of the 20th century two separate lenses were cut in half and combined together in the rim of the frame. The mounting of two half lenses into a single frame led to a number of early complications and rendered such spectacles quite fragile. A method for fusing the sections of the lenses together was developed by Louis de Wecker at the end of the 19th century and patented by Dr. John L. Borsch, Jr. in 1908. Today most bifocals are created by molding a reading segment into a primary lens and are available with the reading segments in a variety of shapes and sizes.The most popular is the D-segment, 28 mm wide. While the D-segment bifocal offers superior optics, an increasing number of people opt for progressive bifocal lenses.

Problems


Bifocals can cause headaches and even dizziness in some users. Acclimation to the small field of view offered by the reading segment of bifocals can take some time, as the user learns to move either the head or the reading material rather than the eyes. Computer monitors are generally placed directly in front of users and can lead to muscle fatigue due to the unusual straight and constant movement of the head. This trouble is mitigated by the use of trifocal lenses or by the use of monofocal lenses for computer users.

In an interesting legal case reported in the UK in 1969, the plaintiff’s ability to use bifocals was impaired by accident.

Future


Research continues in an attempt to eliminate the limited field of vision in current bifocals. New materials and technologies may provide a method which can selectively adjust the optical power of a lens. Researchers have constructed such a lens using a liquid crystal layer sandwiched between two glass substrates.

Bifocals in the animal world


The aquatic larval stage of the diving beetle Thermonectus marmoratus has, in its principal eyes, two retinas and two distinct focal planes that are substantially separated (in the manner of bifocals) to switch their vision from up-close to distance, for easy and efficient capture of their prey, mostly mosquito larvae. This is the first ever recorded use of bifocal technology in the animal world.

Franklin Stove

From Wikipedia, the free encyclopedia

The Franklin stove is a metal-lined fireplace named after Benjamin Franklin, who invented it in 1741. It had a hollow baffle near the rear (to transfer more heat from the fire to a room’s air) and relied on an “inverted siphon” to draw the fire’s hot fumes around the baffle. It was intended to produce more heat and less smoke than an ordinary open fireplace. It is also known as a “circulating stove” or the “Pennsylvania fireplace”.

Franklin_stove

A Franklin stove

History


The two distinguishing features of Franklin’s stove were a hollow baffle (i.e., a metal panel that directed the flow of the fire’s fumes) and a flue that acted as an upside-down siphon.

Franklin_stove,_cross-sectional_diagram

The Franklin stove. Cool air enters the baffle through a duct under the floor. Smoke exits through a U-shaped duct in the floor.

Baffles in fireplaces

Baffles were used to lengthen the path that either a room’s air or a fire’s fumes had to flow through ductwork, thereby allowing more heat to be transferred to the room’s air or from the fire’s fumes. Specifically, ducts could be installed within the brickwork around a hearth; cool room air would then enter the lower end of a duct, be heated by the hot walls of the duct, rise, and finally exit from the duct’s upper end and return to the room. The longer the path through which the air flowed, the more heat would be transferred from the fire to the air. Similarly, the longer the duct through which a fire’s fumes had to flow before reaching the chimney, more heat would be transferred from the fumes to the room’s air.

The use of baffles to extract more heat from a fire and its fumes was not new. In 1618, Franz Kessler (ca. 1580–1650) of Frankfurt-am-Main, Germany published Holzsparkunst (The Art of Saving Wood), featuring a stove in which the fumes from a fire were forced to snake through five chambers, one above the other, before entering the chimney. Kessler also documented an enclosed heating stove that, like Franklin’s stove, had a baffle directly behind the fire, thereby lengthening the path that the fire’s fumes had to travel before reaching the chimney.

In 1624, a French physician, Louis Savot (1579–1640), described a fireplace that he had built in the Louvre. Ducts passed under, behind, and above the fire in the hearth. Cool air in the room entered the lower opening of a duct, was warmed, rose, and returned to the room through the duct’s upper opening. In 1713, Frenchman Nicolas Gauger (ca. 1680–1730) published a book, La Mécanique du Feu… (The Mechanics of Fire), in which he presented novel designs for fireplaces. Gauger surrounded the hearth with hollow spaces. Inside these spaces were baffles. Cool room air entered the spaces through lower openings, was warmed as it snaked around the baffles in the spaces, and returned to the room through upper openings.

In Franklin’s stove, a hollow baffle was positioned inside and near the rear of the stove. The baffle was a wide but thin cast-iron box, which was open to the room’s air at its bottom and at two holes on its sides, near its top. Air entered the bottom of the box and was heated both by the fire and by the fumes flowing over the front and back of the box. The warmed air then rose inside the baffle and exited through the holes in the baffle’s sides. Franklin’s baffle thus performed at least two functions: like Kessler’s heating stove, it lengthened the path that the fire’s fumes had to follow before reaching the chimney, allowing more heat to be extracted from the fumes; and like Gauger’s fireplace, it placed a duct near the fire, which heated the room’s air via convection.

Inverted siphons in fireplaces

Some early experimenters reasoned that if a fire in a fireplace were connected by a U-shaped duct to the chimney, the hot gases ascending through the chimney would draw the fire’s smoke and fumes first downwards through one leg of the U and then upwards through the other leg and the chimney. This was what Franklin called an “aerial syphon” or “syphon revers’d”. This inverted siphon was used to draw the fire’s hot fumes up the front and down the back of the Franklin stove’s hollow baffle, in order to extract as much heat as possible from the fumes.

The earliest known example of such an inverted siphon was the 1618 fireplace of Franz Kessler. The fire burned in a ceramic box. Inside the box and behind the fire was a baffle. The baffle forced the fire’s fumes to descend behind the baffle before exiting to the chimney. The intention was to extract as much heat as possible from the fumes by extending the path that the fumes had to follow before they reached the chimney.

The 1678 fireplace of Prince Rupert (1619–1682) also included an inverted siphon. Rupert placed a hanging iron door between the fire grate and the chimney. In order to exit through the chimney, the fire’s fumes and smoke first had to descend below the edge of the door before rising through the chimney.

Another early example of an inverted siphon was a stove that was exhibited in 1686 at the annual Foire Saint-Germain, Paris. Its inventor, André Dalesme (1643–1727), called it a smokeless stove (furnus acapnos). The stove consisted of an iron bowl in which the fuel was burned. A pipe extended from the bowl’s bottom and then upwards into a chimney. Shortly after starting a fire in the bowl, hot air would begin to rise through the pipe and then up the chimney; this created a downward draft through the bowl, which drew the fire and its fumes down into the bowl. Once the draft was initiated, it was self-sustaining as long as the fire burned. Dalesme’s stove could burn wood, incense, and even “coal steept in cats-piss” yet produce very little smoke or smell. These results showed that fires could be used inside a room, without filling the house with smoke.

Franklin’s stove contained a baffle directly behind the fire, which forced the fire’s fumes to flow downward before they reached the chimney. This required a U-shaped duct in the floor behind the stove, so that the fumes could flow from the stove into the chimney. Thus Franklin’s stove incorporated an inverted siphon.

Franklin’s research and development

Gauger’s book on his innovative fireplace designs was translated into English – Fires Improv’d: Being a New Method of Building Chimneys, So as to Prevent their Smoaking (1715) – by a French immigrant to England, Jean Théophile Desaguliers (1683–1744). In a postscript to Desaguliers’ book A Course in Experimental Philosophy (1744), Desaguliers again briefly described Gauger’s fireplaces and mentioned his own work on the subject. Franklin read both of Desaguliers’ books and developed his own designs for a stove that could provide more heat with less smoke.

In 1742, Franklin finished his first design which implemented new scientific concepts about heat which had been developed by the Dutch physician Herman Boerhaave (1668–1738), a proponent of Isaac Newton’s ideas. Two years later, Franklin wrote a pamphlet describing his design and how it operated in order to sell his product. Around this time, the deputy governor of Pennsylvania, George Thomas, made an offer to Franklin to patent his design, but Franklin never patented any of his designs and inventions. He believed “that as we enjoy great advantages from the inventions of others, we should be glad of an opportunity to serve others by any invention of ours, and this we should do freely and generously”. As a result, many others were able to use Franklin’s design and improve it. Although his stove was intended to have the double purpose of cooking and heating a room, as time progressed and new stove designs became available, the Franklin stove’s main use became to heat a room. Many others improved on the Franklin stove design, but to this day, most American fireplaces are box-shaped, similar to the Franklin stove. The exception is the Rumford fireplace, developed by Benjamin Thompson.

Stove Design


The stove was about 30 inches (76 cm) tall, with a box shape. The front was open, except for a decorative panel in the upper part of the box. The back of the box was to be placed a few inches away from the flue (chimney). On the bottom panel there were several holes to allow the smoke to escape; these were connected to the chimney. The panels were bolted together with iron screws through pre-cast ears. Inside there was a small, thin rectangular prism that would force the smoke into the holes. The plates were all made from iron.

Franklin’s stove sold poorly. The problem lay with the inverted siphon: the smoke had to pass through a cold flue (which was set in the floor) before the smoke could enter the chimney; consequently, the smoke cooled too much and the stove did not have a good draft. The inverted siphon would operate properly only if the fire burned constantly, so that the temperature in the flue was high enough to produce a draft.

A later version, designed by David Rittenhouse, solved many of the problems Franklin’s original stove had and became popular. Franklin’s fame outweighed Rittenhouse’s, though, so history remembers the Franklin Stove rather than the Rittenhouse Stove.

Glass Harmonica

From Wikipedia, the free encyclopedia

800px-ThomasBlochHandsGlassharmonica_low_notes_on_left_and_high_notes_on_right

Spinning glass disks (bowls) on a common shaft are arranged with the lower notes (larger disks) to the left and higher notes (smaller disks) to the right.

The glass harmonica, also known as the glass armonica, glass harmonium, bowl organ, hydrocrystalophone, or simply the armonica or harmonica (derived from ἁρμονία, harmonia, the Greek word for harmony), is a type of musical instrument that uses a series of glass bowls or goblets graduated in size to produce musical tones by means of friction (instruments of this type are known as friction idiophones).

Names


436px-Glass.harmonica.in.rome.arp

A glass harp, an ancestor of the glass armonica, being played in Rome. The rims of wine glasses filled with water are rubbed by the player’s fingers to create the notes.

The name “glass harmonica” (also “glass armonica”, “glassharmonica”; harmonica de verre, harmonica de Franklin, armonica de verre, or just harmonica in French; Glasharmonika in German; harmonica in Dutch) refers today to any instrument played by rubbing glass or crystal goblets or bowls. The alternate instrument consisting of a set of wine glasses (usually tuned with water) is generally known in English as “musical glasses” or the “glass harp”.

When Benjamin Franklin invented his mechanical version of the instrument in 1761, he called it the armonica, based on the Italian word armonia, which means “harmony”. The unrelated free-reed wind instrument aeolina, today called the “harmonica”, was not invented until 1821, sixty years later.

The word “hydrodaktulopsychicharmonica” is also recorded, composed of Greek roots to mean something like “harmonica to produce music for the soul by fingers dipped in water” (hydro- for “water”, daktul- for “finger”, psych- for “soul”). The Oxford Companion to Music mentions that this word is “the longest section of the Greek language ever attached to any musical instrument, for a reader of The Times wrote to that paper in 1932 to say that in his youth he heard a performance of the instrument where it was called a hydrodaktulopsychicharmonica.” The Museum of Music in Paris displays a hydrodaktulopsychicharmonica.

Forerunners


Because its sounding portion is made of glass, the glass harmonica is a type of crystallophone. The phenomenon of rubbing a wet finger around the rim of a wine goblet to produce tones is documented back to Renaissance times; Galileo considered the phenomenon (in his Two New Sciences), as did Athanasius Kircher.

The Irish musician Richard Pockrich is typically credited as the first to play an instrument composed of glass vessels (glass harp) by rubbing his fingers around the rims. Beginning in the 1740s, he performed in London on a set of upright goblets filled with varying amounts of water. His career was cut short by a fire in his room, which killed him and destroyed his apparatus.

Edward Delaval, a friend of Benjamin Franklin and a fellow of the Royal Society, extended the experiments of Pockrich, contriving a set of glasses better tuned and easier to play. During the same decade, Christoph Willibald Gluck also attracted attention playing a similar instrument in England.

Franklin’s armonica


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A modern glass armonica built using Benjamin Franklin’s design

Benjamin Franklin invented a radically new arrangement of the glasses in 1761 after seeing water-filled wine glasses played by Edmund Delaval at Cambridge in England in May 1761. Franklin worked with London glassblower Charles James to build one, and it had its world premiere in early 1762, played by Marianne Davies.

Writing to his friend Giambatista Beccaria in Turin, Italy, Franklin wrote from London in 1762 about his musical instrument: “The advantages of this instrument are, that its tones are incomparably sweet beyond those of any other; that they may be swelled and softened at pleasure by stronger or weaker pressures of the finger, and continued to any length; and that the instrument, being well tuned, never again wants tuning. In honour of your musical language, I have borrowed from it the name of this instrument, calling it the Armonica.”

In Franklin’s treadle-operated version, 37 bowls were mounted horizontally on an iron spindle. The whole spindle turned by means of a foot pedal. The sound was produced by touching the rims of the bowls with water-moistened fingers. Rims were painted different colors according to the pitch of the note: A (dark blue), B (purple), C (red), D (orange), E (yellow), F (green), G (blue), and accidentals were marked in white. With the Franklin design, it is possible to play ten glasses simultaneously if desired, a technique that is very difficult if not impossible to execute using upright goblets. Franklin also advocated the use of a small amount of powdered chalk on the fingers, which under some acidic water conditions helped produce a clear tone.

Some attempted improvements on the armonica included adding keyboards, placing pads between the bowls to reduce sympathetic vibrations, and using violin bows. Another supposed improvement claimed in ill-informed post-period observations of non-playing instruments was to have the glasses rotate into a trough of water. However, William Zeitler put this idea to the test by rotating an armonica cup into a basin of water; the water has the same effect as putting water in a wine glass – it changes the pitch. With several dozen glasses, each a different diameter and thus rotating with a different depth, the result would be musical cacophony. This modification also made it much harder to make the glass “speak”, and muffled the sound.

In 1975, an original armonica was acquired by the Bakken Museum in Minneapolis and put on display, albeit without its original glass bowls (they were destroyed during shipment). It was purchased through a musical instrument dealer in France, from the descendants of Mme. Brillon de Jouy, a neighbor of Benjamin Franklin’s from 1777 to 1785, when he lived in the Paris suburb of Passy. Some 18th- and 19th-century specimens of the armonica have survived into the 21st century. Franz Mesmer also played the armonica and used it as an integral part of his Mesmerism.

An original Franklin armonica is in the archives at the Franklin Institute in Philadelphia, having been donated in 1956 by Franklin’s descendants after “the children took great delight in breaking the bowls with spoons” during family gatherings. It is only placed on display for special occasions, such as Franklin’s birthday. The Franklin Institute is also the home of the Benjamin Franklin National Memorial.

A website has attempted to catalog publicly known Franklin-era glass armonicas. The Museum of Fine Arts, Boston has an early 19th-century instrument on display, which is occasionally used for public performances and recordings.

Musical works


Carnaval_aquarium

Part of the original manuscript score of “Aquarium” from The Carnival of the Animals by Camille Saint-Saëns. The top staff was written for the (glass) “Harmonica”. About this sound Play (help·info)

Composers including J. G. Naumann, Padre Martini, Johann Adolph Hasse, Baldassare Galuppi, and Niccolò Jommelli, and more than 100 others composed works for the glass harmonica;   some pieces survive in the repertoire through transcriptions for more conventional instruments. European monarchs indulged in playing it, and even Marie Antoinette took lessons as a child from Franz Anton Mesmer.

Wolfgang Amadeus Mozart wrote his 1791 K. 617 and K.356 (K.617a) for the glass harmonica. Ludwig van Beethoven used the instrument in an 1814 melodrama Leonore Prohaska. Gaetano Donizetti used the instrument in the accompaniment to Amelia’s aria “Par che mi dica ancora” in Il castello di Kenilworth, premiered in 1829. He also originally specified the instrument in Lucia di Lammermoor (1835) as a haunting accompaniment to the heroine’s “mad scenes”, though before the premiere he was required by the producers to rewrite the part for two flutes. Camille Saint-Saëns used this instrument in his 1886 The Carnival of the Animals (in movements 7 and 14). Richard Strauss used the instrument in his 1917 Die Frau ohne Schatten.

For a while the instrument was “extraordinarily popular,” its “‘ethereal” qualities characteristic, along with instruments such as the nail violin and Aeolian harp, of Empfindsamkeit, but “the instrument fell into oblivion,” around 1830. Since the armonica’s performance revival during the 1980s, composers have again written for it (solo, chamber music, opera, electronic music, popular music) including Jan Erik Mikalsen, Regis Campo, Etienne Rolin, Philippe Sarde, Damon Albarn, Tom Waits, Michel Redolfi, Cyril Morin, Stefano Giannotti, Thomas Bloch, Jörg Widmann (Armonica 2006), and Guillaume Connesson.

The music for the 1997 ballet Othello by American composer Elliot Goldenthal opens and closes with the glass harmonica. The ballet was performed at San Francisco Ballet, the American Ballet Theater, the Joffrey Ballet, and on tour in Europe including at the Opera Garnier with Dennis James performing with his historical replica instrument.

George Benjamin’s opera Written on Skin, which premiered at the 2012 Aix-en-Provence Festival, includes a prominent and elaborate part for the glass harmonica..

Purported dangers


The instrument’s popularity did not last far beyond the 18th century. Some claim this was due to strange rumors that using the instrument caused both musicians and their listeners to go mad. It is a matter of conjecture how pervasive that belief was; all the commonly cited examples of this rumor seems to be German, if not confined to Vienna. One example of alleged effects from playing the glass harmonica was noted by a German musicologist Friedrich Rochlitz in the Allgemeine Musikalische Zeitung:

The harmonica excessively stimulates the nerves, plunges the player into a nagging depression and hence into a dark and melancholy mood that is apt method for slow self-annihilation. If you are suffering from any kind of nervous disorder, you should not play it; if you are not yet ill you should not play it; if you are feeling melancholy you should not play it.

Marianne Davies, who played flute and harpsichord – and was a young woman said to be related to Franklin – became proficient enough at playing the armonica to offer public performances. After touring for many years in duo performances with her celebrated vocalist sister, she was also said to have been afflicted with a melancholia attributed to the plaintive tones of the instrument. Marianne Kirchgessner was an armonica player; she died at the age of 39 of pneumonia or an illness much like it. However many others, including Franklin, lived long lives.

For a time the armonica achieved a genuine vogue, but like most fads, that for the armonica eventually passed. It has been claimed the sound-producing mechanism did not generate sufficient power to fill the large halls that were becoming home to modern stringed instruments, brass, woodwinds, and percussion. That the instrument was made with glass, and subject to easy breakage, perhaps did not help either. By 1820, the armonica had mostly disappeared from frequent public performance, perhaps because musical fashions were changing.

A modern version of the “purported dangers” claims that players suffered lead poisoning because armonicas were made of lead glass. However, there is no known scientific basis for the theory that merely touching lead glass can cause lead poisoning. Lead poisoning was common in the 18th and early 19th centuries for both armonica players and non-players alike; doctors prescribed lead compounds for a long list of ailments, and lead or lead oxide was used as a food preservative and in cookware and eating utensils. Trace amounts of lead that armonica players in Franklin’s day received from their instruments would likely have been dwarfed by lead from other sources, such as the lead-content paint used to mark visual identification of the bowls to the players.

Historical replicas by Eisch use so-called “White Crystal” developed in the 18th c. replacing the lead with a higher potash content; many modern newly invented devices, such as those made by Finkenbeiner, are made from so-called Quartz “pure silica glass” – a glass formulation developed in the early 20th c. for scientific purposes.

Perception of the sound


The somewhat disorienting quality of the ethereal sound is due in part to the way that humans perceive and locate ranges of sounds. Above 4 kHz people primarily use the loudness of the sound to differentiate between left and right ears and thus triangulate, or locate the source. Below 1 kHz, they use the phase differences of sound waves arriving at their left and right ears to identify location. The predominant pitch of the armonica is in the range of 1–4 kHz, which coincides with the sound range where the brain is “not quite sure”, and thus listeners have difficulty locating it in space (where it comes from), and discerning the source of the sound (the materials and techniques used to produce it).

Benjamin Franklin himself described the armonica’s tones as “incomparably sweet”. The full quotation, written in a letter to Giambattista Beccaria, an Italian priest and electrician, is: “The advantages of this instrument are that its tones are incomparably sweet beyond those of any other; that they may be swelled and softened at pleasure by stronger or weaker pressures of the finger, and continued to any length; and that the instrument, once well tuned, never again wants tuning.”

A music critic for the Morning Chronicle, writing of a performance by Kirchgessner in 1794, said, “Her taste is chastened and the dulcet notes of the instrument would be delightful indeed, were they more powerful and articulate; but that we believe the most perfect execution cannot make them. In a smaller room and an audience less numerous, the effect must be enchanting. Though the accompaniments were kept very much under, they were still occasionally too loud.”

Modern revival


800px-Glass_Harmonica_at_Poncan_Theatre

Dennis James plays the armonica at the Poncan Theatre in Ponca City, Oklahoma, on April 2, 2011.

Music for glass harmonica was all-but-unknown from 1820 until the 1930s (although Gaetano Donizetti intended for the aria “Il dolce suono” from his 1835 opera Lucia di Lammermoor to be accompanied by a glass armonica, and Richard Strauss specified use of the instrument in his 1919 opera Die Frau ohne Schatten), when German virtuoso Bruno Hoffmann began revitalizing interest in his individual goblet instrument version that he named the glass harp for his stunning performances. Playing his “glass harp” (with Eisch manufactured custom designed glasses mounted in a case designed with underlying resonance chamber) he transcribed or rearranged much of the literature written for the mechanized instrument, and commissioned contemporary composers to write new pieces for his goblet version.

Franklin’s glass armonica design was reworked yet again without patent credit by master glassblower and musician, Gerhard B. Finkenbeiner (1930–1999) in 1984. After thirty years of experimentation, Finkenbeiner’s imitative prototype consisted of clear glasses and glasses later equipped with gold bands mimicking late 18th-century designs. The historical instruments with gold bands indicated the equivalent of the black keys on the piano, simplifying the multi-hued painted bowl rims with white accidentals as specified by Franklin. Finkenbeiner Inc., of Waltham, Massachusetts, continues to produce versions of these instruments commercially as of 2014, featuring glass elements made of scientific formulated fused-silica quartz.

French instrument makers and artists Bernard and François Baschet invented a modern variation of the Chladni Euphone in 1952, the “crystal organ” or Cristal di Baschet, which consists of up to 52 chromatically tuned resonating metal rods that are set into motion by attached glass rods that are rubbed with wet fingers. The Cristal di Baschet differs mainly from the other glass instruments in that the identical length and thickness glass rods are set horizontally, and attach to the tuned metal stems that have added metal blocks for increasing resonance. The result is a fully acoustic instrument, and impressive amplification obtained using fiberglass or metal cones fixed on wood and by a tall cut-out multi-resonant metal part in the shape of a flame. Some thin added metallic wires resembling cat whiskers are placed under the instrument, supposedly to increase the sound power of high-pitched frequencies.

Dennis James recorded an album of all glass music, Cristal: Glass Music Through the Ages co-produced by Linda Ronstadt and Grammy Award-winning producer John Boylan. James plays the glass harmonica, the Cristal di Baschet, and the Seraphim on the CD in original historical compositions and new arrangements for glass by Mozart, Scarlatti, Schnaubelt, and Fauré and collaborates on the recording with the Emerson String Quartet, operatic soprano Ruth Ann Swenson, and Ronstadt. James played glass instruments on Marco Beltrami’s film scores for The Minus Man (1999) and The Faculty (1998). “I first became aware of glass instruments at about the age of 6 while visiting the Franklin Institute in Philadelphia. I can still recall being mesmerized by the appearance of the original Benjamin Franklin armonica then on display in its own showcase in the entry rotunda of the city’s famed science museum.” James Horner used a glass harmonica and pan flute for Spock’s theme in the 1982 film Star Trek II: The Wrath of Khan.

Notable players


Historical

  • Marie Antoinette
  • Marianne Davies
  • Benjamin Franklin (United States)
  • Franz Mesmer
  • Marianne Kirchgessner
  • Mrs. Philip Thicknesse (born Anne Ford), 1775, United Kingdom)

Contemporary

  • Thomas Bloch (France)
  • Cecilia Brauer (United States)
  • Bill Hayes (New York City) Broadway Musician and Percussionist, Barbra Streisand Orchestra 1994, 2006, 2007
  • Martin Hilmer (Germany)
  • Bruno Hoffmann (Germany)
  • Dennis James (United States)
  • Alasdair Malloy (United Kingdom)
  • David Mauldin (United States)
  • Gloria Parker (United States) glass harp
  • Gerald Schönfeldinger (Austria)
  • Dean Shostak (United States)
  • Ed Stander (United States)
  • William Zeitler (United States)

Related instruments


Glassharmonica

An armonica

Another instrument that is also played with wet fingers is the hydraulophone.   The hydraulophone sounds similar to a glass armonica but has a darker, heavier sound, that extends down into the subsonic range. The technique for playing the hydraulophone is similar to that used for playing the armonica.

Lightning Rod

From Wikipedia, the free encyclopedia

Lightning-rod-diagram.svg

Diagram of a simple lightning protection system

A lightning rod (US, AUS) or lightning conductor (UK) is a metal rod mounted on a structure and intended to protect the structure from a lightning strike. If lightning hits the structure, it will preferentially strike the rod and be conducted to ground through a wire, instead of passing through the structure, where it could start a fire or cause electrocution. Lightning rods are also called finials, air terminals or strike termination devices.

In a lightning protection system, a lightning rod is a single component of the system. The lightning rod requires a connection to earth to perform its protective function. Lightning rods come in many different forms, including hollow, solid, pointed, rounded, flat strips or even bristle brush-like. The main attribute common to all lightning rods is that they are all made of conductive materials, such as copper and aluminum. Copper and its alloys are the most common materials used in lightning protection.

History


The principle of the lightning rod was first detailed by Benjamin Franklin in Pennsylvania in 1749, who in the subsequent years developed his invention for household application (published in 1753) and further improvements towards a reliable system around 1760.

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Nevyansk Tower in Russia crowned with a metallic rod grounded through a complex system of rebars (some are seen at the basement)

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“Machina meteorologica” invented by Diviš worked like a lightning rod

Franklin_-_Sentry-Box_Experiment

Franklin’s earliest papers on electricity

As buildings become taller, lightning becomes more of a threat. Lightning can damage structures made of most materials, such as masonry, wood, concrete and steel, because the huge currents and voltages involved can heat materials to high temperature, causing a potential for fire.

Russia

A lightning conductor may have been intentionally used in the Leaning Tower of Nevyansk. The spire of the tower is crowned with a metallic rod in the shape of a gilded sphere with spikes. This lightning rod is grounded through the rebar carcass, which pierces the entire building.

The Nevyansk Tower was built between 1721 and 1745, on the orders of industrialist Akinfiy Demidov. The Nevyansk Tower was built 28 years before Benjamin Franklin’s experiment and scientific explanation. However, the true intent behind the metal rooftop and rebars remains unknown.

Europe

The church tower of many European cities, which was usually the highest structure in the city, was likely to be hit by lightning. Early on, Christian churches tried to prevent the occurrence of the damaging effects of lightning by prayers. Peter Ahlwardts (“Reasonable and Theological Considerations about Thunder and Lightning”, 1745) advised individuals seeking cover from lightning to go anywhere except in or around a church.

There is an ongoing debate over whether a “metereological machine”, invented by Premonstratensian priest Prokop Diviš and erected in Přímětice near Znojmo, Moravia (now Czech Republic) in June 1754, does count as an individual invention of the lightning rod. Diviš’s apparatus was, according to his private theories, aimed towards preventing thunderstorms altogether by constantly depriving the air of its superfluous electricity. The apparatus was, however, mounted on a free-standing pole and probably better grounded than Franklin’s lightning rods at that time, so it served the purpose of a lightning rod. After local protests, Diviš had to cease his weather experiments around 1760.

America

In what later became the United States, the pointed lightning rod conductor, also called a lightning attractor or Franklin rod, was invented by Benjamin Franklin in 1749 as part of his groundbreaking exploration of electricity. Although not the first to suggest a correlation between electricity and lightning, Franklin was the first to propose a workable system for testing his hypothesis. Franklin speculated that, with an iron rod sharpened to a point,

“The electrical fire would, I think, be drawn out of a cloud silently, before it could come near enough to strike….”

Franklin speculated about lightning rods for several years before his reported kite experiment. This experiment, it is said, took place because he was tired of waiting for Christ Church in Philadelphia to be completed so he could place a lightning rod on top of it.  

In the 19th century, the lightning rod became a decorative motif. Lightning rods were embellished with ornamental glass balls (now prized by collectors). The ornamental appeal of these glass balls has been used in weather vanes. The main purpose of these balls, however, is to provide evidence of a lightning strike by shattering or falling off. If after a storm a ball is discovered missing or broken, the property owner should then check the building, rod, and grounding wire for damage.

Balls of solid glass occasionally were used in a method purported to prevent lightning strikes to ships and other objects. The idea was that glass objects, being non-conductors, are seldom struck by lightning. Therefore, goes the theory, there must be something about glass that repels lightning. Hence the best method for preventing a lightning strike to a wooden ship was to bury a small solid glass ball in the tip of the highest mast. The random behavior of lightning combined with observers’ confirmation bias ensured that the method gained a good bit of credence even after the development of the marine lightning rod soon after Franklin’s initial work.

The first lightning conductors on ships were supposed to be hoisted when lightning was anticipated, and had a low success rate. In 1820 William Snow Harris invented a successful system for fitting lightning protection to the wooden sailing ships of the day, but despite successful trials which began in 1830, the British Royal Navy did not adopt the system until 1842, by which time the Imperial Russian Navy had already adopted the system.

In the 1990s, the ‘lightning points’ were replaced as originally constructed when the Statue of Freedom atop the United States Capitol building in Washington, D.C. was restored. The statue was designed with multiple devices that are tipped with platinum. The Washington Monument also was equipped with multiple lightning points, and the Statue of Liberty in New York Harbor gets hit by lightning, which is shunted to ground.

Lightning Protection System


A lightning protection system is designed to protect a structure from damage due to lightning strikes by intercepting such strikes and safely passing their extremely high currents to ground. A lightning protection system includes a network of air terminals, bonding conductors, and ground electrodes designed to provide a low impedance path to ground for potential strikes.

Lightning protection systems are used to prevent or lessen lightning strike damage to structures. Lightning protection systems mitigate the fire hazard which lightning strikes pose to structures. A lightning protection system provides a low-impedance path for the lightning current to lessen the heating effect of current flowing through flammable structural materials. If lightning travels through porous and water-saturated materials, these materials may literally explode if their water content is flashed to steam by heat produced from the high current. This is why trees are often shattered by lightning strikes.

Because of the high energy and current levels associated with lightning (currents can be in excess of 150,000 amps), and the very rapid rise time of a lightning strike, no protection system can guarantee absolute safety from lightning. Lightning current will divide to follow every conductive path to ground, and even the divided current can cause damage. Secondary “side-flashes” can be enough to ignite a fire, blow apart brick, stone, or concrete, or injure occupants within a structure or building. However, the benefits of basic lightning protection systems have been evident for well over a century.

Laboratory-scale measurements of the effects of [any lightning investigation research] do not scale to applications involving natural lightning. Field applications have mainly been derived from trial and error based on the best intended laboratory research of a highly complex and variable phenomenon.

The parts of a lightning protection system are air terminals (lightning rods or strike termination devices), bonding conductors, ground terminals (ground or “earthing” rods, plates, or mesh), and all of the connectors and supports to complete the system. The air terminals are typically arranged at or along the upper points of a roof structure, and are electrically bonded together by bonding conductors (called “down conductors” or “downleads”), which are connected by the most direct route to one or more grounding or earthing terminals. Connections to the earth electrodes must not only have low resistance, but must have low self-inductance.

An example of a structure vulnerable to lightning is a wooden barn. When lightning strikes the barn, the wooden structure and its contents may be ignited by the heat generated by lightning current conducted through parts of the structure. A basic lightning protection system would provide a conductive path between an air terminal and earth, so that most of the lightning’s current will follow the path of the lightning protection system, with substantially less current traveling through flammable materials.

A controversy over the assortment of operation theories dates back to the 18th century, when Benjamin Franklin himself stated that his lightning protectors protected buildings by dissipating electric charge. He later retracted the statement, stating that the device’s exact mode of operation was something of a mystery at that point.  

Originally, scientists believed that such a lightning protection system of air terminals and “downleads” directed the current of the lightning down into the earth to be “dissipated”. However, high speed photography has clearly demonstrated that lightning is actually composed of both a cloud component and an oppositely charged ground component. During “cloud-to-ground” lightning, these oppositely charged components usually “meet” somewhere in the atmosphere well above the earth to equalize previously unbalanced charges. The heat generated as this electric current flows through flammable materials is the hazard which lightning protection systems attempt to mitigate by providing a low-resistance path for the lightning circuit. No lightning protection system can be relied upon to “contain” or “control” lightning completely (nor thus far, to prevent lightning strikes entirely), but they do seem to help immensely on most occasions of lightning strikes.

Steel framed structures can bond the structural members to earth to provide lightning protection. A metal flagpole with its foundation in the earth is its own extremely simple lightning protection system. However, the flag(s) flying from the pole during a lightning strike may be completely incinerated.

The majority of lightning protection systems in use today are of the traditional Franklin design. The fundamental principle used in Franklin-type lightning protections systems is to provide a sufficiently low impedance path for the lightning to travel through to reach ground without damaging the building. This is accomplished by surrounding the building in a kind of Faraday cage. A system of lightning protection conductors and lightning rods are installed on the roof of the building to intercept any lightning before it strikes the building.

Structure Protectors


Lightingrodplacement

Landscape suited for purpose of explanation: (1) Represents Lord Kelvin’s “reduced” area of the region; (2) Surface concentric with the Earth such that the quantities stored over it and under it are equal; (3) Building on a site of excessive electrostatic charge density; (4) Building on a site of low electrostatic charge density. (Image via U.S. Patent 1,266,175.)

Lightning arrester

335px-Statue_auf_dem_Bayerischen_Landtag_3427

Lightning rod on a statue.

In telegraphy and telephony, a lightning arrester is a device placed where wires enter a structure, in order to prevent damage to electronic instruments within and ensuring the safety of individuals near the structures. Lightning arresters, also called surge protectors, are devices that are connected between each electrical conductor in a power or communications system, and the ground. They help prevent the flow of the normal power or signal currents to ground, but provide a path over which high-voltage lightning current flows, bypassing the connected equipment. Arresters are used to limit the rise in voltage when a communications or power line is struck by lightning or is near to a lightning strike.

Protection of electric distribution systems

In overhead electric transmission (high-tension) systems, one or two lighter gauge conductors may be mounted to the top of the pylons, poles, or towers not specifically used to send electricity through the grid. These conductors, often referred to “static”, “pilot” or “shield” wires are designed to be the point of lightning termination instead of the high-voltage lines themselves. These conductors are intended to protect the primary power conductors from lightning strikes.

These conductors are bonded to earth either through the metal structure of a pole or tower, or by additional ground electrodes installed at regular intervals along the line. As a general rule, overhead power lines with voltages below 50 kV do not have a “static” conductor, but most lines carrying more than 50 kV do. The ground conductor cable may also support fibre optic cables for data transmission.

In some instances, these conductors are insulated from direct bonding with earth and may be used as low voltage communication lines. If the voltage exceeds a certain threshold, such as during a lightning termination to the conductor, it “jumps” the insulators and passes to earth.

Protection of electrical substations is as varied as lightning rods themselves, and is often proprietary to the electric company.

Lightning protection of mast radiators

Radio mast radiators may be insulated from the ground by a gap at the base. When lightning hits the mast, it jumps this gap. A small inductivity in the feed line between the mast and the tuning unit (usually one winding) limits the voltage increase, protecting the transmitter from dangerously high voltages. The transmitter must be equipped with a device to monitor the antenna’s electrical properties. This is very important, as a charge could remain after a lightning strike, damaging the gap or the insulators. The monitoring device switches off the transmitter when the antenna shows incorrect behavior, e.g. as a result of undesired electrical charge. When the transmitter is switched off, these charges dissipate. The monitoring device makes several attempts to switch back on. If after several attempts the antenna continues to show improper behavior, possibly as result of structural damage, the transmitter remains switched off.

Lightning conductors and grounding precautions

Ideally, the underground part of the assembly should reside in an area of high ground conductivity. If the underground cable is able to resist corrosion well, it can be covered in salt to improve its electrical connection with the ground. While the electrical resistance of the lightning conductor between the air terminal and the Earth is of significant concern, the inductive reactance of the conductor could be more important. For this reason, the down conductor route is kept short, and any curves have a large radius. If these measures are not taken, lightning current may arc over a resistive or reactive obstruction that it encounters in the conductor. At the very least, the arc current will damage the lightning conductor and can easily find another conductive path, such as building wiring or plumbing, and cause fires or other disasters. Grounding systems without low resistivity to the ground can still be effective in protecting a structure from lightning damage. When ground soil has poor conductivity, is very shallow, or non-existent, a grounding system can be augmented by adding ground rods, counterpoise (ground ring) conductor, cable radials projecting away from the building, or a concrete building’s reinforcing bars can be used for a ground conductor (Ufer ground). These additions, while still not reducing the resistance of the system in some instances, will allow the [dispersion] of the lightning into the earth without damage to the structure.

Additional precautions must be taken to prevent side-flashes between conductive objects on or in the structure and the lightning protection system. The surge of lightning current through a lightning protection conductor will create a voltage difference between it and any conductive objects that are near it. This voltage difference can be large enough to cause a dangerous side-flash (spark) between the two that can cause significant damage, especially on structures housing flammable or explosive materials. The most effective way to prevent this potential damage is to ensure the electrical continuity between the lightning protection system and any objects susceptible to a side-flash. Effective bonding will allow the voltage potential of the two objects to rise and fall simultaneously, thereby eliminating any risk of a side-flash.

Lightning protection system design

Considerable material is used to make up lightning protection systems, so it is prudent to consider carefully where an air terminal will provide the greatest protection. Historical understanding of lightning, from statements made by Ben Franklin, assumed that each lightning rod protected a cone of 45 degrees. This has been found to be unsatisfactory for protecting taller structures, as it is possible for lightning to strike the side of a building.

A modeling system based on a better understanding of the termination targeting of lightning, called the Rolling Sphere Method, was developed by Dr Tibor Horváth. It has become the standard by which traditional Franklin Rod systems are installed. To understand this requires knowledge of how lightning ‘moves’. As the step leader of a lightning bolt jumps toward the ground, it steps toward the grounded objects nearest its path. The maximum distance that each step may travel is called the critical distance and is proportional to the electric current. Objects are likely to be struck if they are nearer to the leader than this critical distance. It is standard practice to approximate the sphere’s radius as 46 m near the ground.

An object outside the critical distance is unlikely to be struck by the leader if there is a solidly grounded object within the critical distance. Locations that are considered safe from lightning can be determined by imagining a leader’s potential paths as a sphere that travels from the cloud to the ground. For lightning protection, it suffices to consider all possible spheres as they touch potential strike points. To determine strike points, consider a sphere rolling over the terrain. At each point, a potential leader position is simulated. Lightning is most likely to strike where the sphere touches the ground. Points that the sphere cannot roll across and touch are safest from lightning. Lightning protectors should be placed where they will prevent the sphere from touching a structure. A weak point in most lightning diversion systems is in transporting the captured discharge from the lightning rod to the ground, though. Lightning rods are typically installed around the perimeter of flat roofs, or along the peaks of sloped roofs at intervals of 6.1 m or 7.6 m, depending on the height of the rod. When a flat roof has dimensions greater than 15 m by 15 m, additional air terminals will be installed in the middle of the roof at intervals of 15 m or less in a rectangular grid pattern.

Rounded versus pointed ends

Pointed_Lightning_Rod

Pointed lightning rod on a building

The optimal shape for the tip of a lightning rod has been controversial since the 18th century. During the period of political confrontation between Britain and its American colonies, British scientists maintained that a lightning rod should have a ball on its end, while American scientists maintained that there should be a point. As of 2003, the controversy had not been completely resolved. It is difficult to resolve the controversy because proper controlled experiments are nearly impossible, but work performed by Charles B. Moore, et al., in 2000 has shed some light on the issue, finding that moderately rounded or blunt-tipped lightning rods act as marginally better strike receptors. As a result, round-tipped rods are installed on most new systems in the United States, though most existing systems still have pointed rods. According to the study,

[c]alculations of the relative strengths of the electric fields above similarly exposed sharp and blunt rods show that while the fields are much stronger at the tip of a sharp rod prior to any emissions, they decrease more rapidly with distance. As a result, at a few centimeters above the tip of a 20-mm-diameter blunt rod, the strength of the field is greater than over an otherwise similar, sharper rod of the same height. Since the field strength at the tip of a sharpened rod tends to be limited by the easy formation of ions in the surrounding air, the field strengths over blunt rods can be much stronger than those at distances greater than 1 cm over sharper ones.

The results of this study suggest that moderately blunt metal rods (with tip height to tip radius of curvature ratios of about 680:1) are better lightning strike receptors than sharper rods or very blunt ones.

In addition, the height of the lightning protector relative to the structure to be protected and the Earth itself will have an effect.

Charge Transfer theory

The Charge Transfer theory states that a lightning strike to a protected structure can be prevented by reducing the electrical potential between the protected structure and the thundercloud. This is done by transferring electric charge (such as from the nearby Earth to the sky or vice versa). Transferring electric charge from the Earth to the sky is done by installing engineered products composed of many points above the structure. It is noted that pointed objects will indeed transfer charge to the surrounding atmosphere and that a considerable electric current can be measured through the conductors as ionization occurs at the point when an electric field is present, such as happens when thunderclouds are overhead.

In the United States, the National Fire Protection Association (NFPA) does not currently[when?] endorse a device that can prevent or reduce lightning strikes. The NFPA Standards Council, following a request for a project to address Dissipation Array[tm] Systems and Charge Transfer Systems, denied the request to begin forming standards on such technology (though the Council did not foreclose on future standards development after reliable sources demonstrating the validity of the basic technology and science were submitted).

Early streamer emission (ESE) theory

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ESE lightning rod mounted at the Monastery of St. Nicholas Anapausas (Μονή του Αγίου Νικολάου), Meteora, Greece

The theory of early streamer emission proposes that if a lightning rod has a mechanism producing ionization near its tip, then its lightning capture area is greatly increased. At first, small quantities of radioactive isotopes (radium-226 or americium-241) were used as sources of ionization between 1930 and 1980, later replaced with various electrical and electronic devices. According to an early patent, since most lightning protectors’ ground potentials are elevated, the path distance from the source to the elevated ground point will be shorter, creating a stronger field (measured in volts per unit distance) and that structure will be more prone to ionization and breakdown.

AFNOR, the French national standardization body, issued a standard, NF C 17-102, covering this technology. The NFPA also investigated the subject and there was a proposal to issue a similar standard in the USA. Initially, an NFPA independent third party panel stated that “the [Early Streamer Emission] lightning protection technology appears to be technically sound” and that there was an “adequate theoretical basis for the [Early Streamer Emission] air terminal concept and design from a physical viewpoint”.) The same panel also concluded that “the recommended [NFPA 781 standard] lightning protection system has never been scientifically or technically validated and the Franklin rod air terminals have not been validated in field tests under thunderstorm conditions.”

In response, the American Geophysical Union concluded that “[t]he Bryan Panel reviewed essentially none of the studies and literature on the effectiveness and scientific basis of traditional lightning protection systems and was erroneous in its conclusion that there was no basis for the Standard.” AGU did not attempt to assess the effectiveness of any proposed modifications to traditional systems in its report. The NFPA withdrew its proposed draft edition of standard 781 due to a lack of evidence of increased effectiveness of Early Streamer Emission-based protection systems over conventional air terminals.

Members of the Scientific Committee of the International Conference on Lightning Protection (ICLP) have issued a joint statement stating their opposition to Early Streamer Emission technology. ICLP maintains a web page with information related to ESE and related technologies. Still, the number of buildings and structures equipped with ESE lightning protection systems is growing as well as the number of manufacturers of ESE air terminals from Europe, Americas, Middle East, Russia, China, South Korea, ASEAN countries, and Australia.

Analysis of Strikes


Lightning strikes to a metallic structure can vary from leaving no evidence, except perhaps, a small pit in the metal, to the complete destruction of the structure. When there is no evidence, analyzing the strikes is difficult. This means that a strike on an uninstrumented structure must be visually confirmed, and the random behavior of lightning renders such observations difficult. There are also inventors working on this problem, such as through a lightning rocket. While controlled experiments may be off in the future, very good data is being obtained through techniques which use radio receivers that watch for the characteristic electrical ‘signature’ of lightning strikes using fixed directional antennas. Through accurate timing and triangulation techniques, lightning strikes can be located with great precision, so strikes on specific objects often can be confirmed with confidence.

The energy in a lightning strike is typically in the range of 1 to 10 billion joules. This energy is released usually in a small number of separate strokes, each with duration of a few tens of microseconds (typically 30 to 50 microseconds), over a period of about one fifth of a second. The great majority of the energy is dissipated as heat, light and sound in the atmosphere.

Aircraft Protectors


Lightning protection for aircraft is provided by mounting devices on the aircraft structure. The protectors are provided with extensions through the structure of the aircraft’s outer surface and within a static discharger. Protection systems for use in aircraft must protect critical and non-critical electronic equipment. Aircraft lightning protection provides an electrical path having a plurality of conductive segments, continuous or discontinuous, that upon exposure to a high voltage field form an ionization channel due to the system’s breakdown voltage. Various lightning protection systems must reject the surge currents associated with the lightning strikes. Lightning protection means for aircraft include components which are dielectrics and metallic layers applied to the ordinarily lightning-accessible surfaces of composite structures. Various ground connection means to the layers comprises a section of wire mesh fusing the various layers to an attachment connecting the structure to an adjacent ground structure. Composite-to-metal or composite-to-composite structural joints are protected by making the interface areas conductive for transfer of lightning current.

Some aircraft lightning protection systems use a shielded cable system. These systems consist of one or more conductors enclosed by a conductive shield. The cable has both conductors of one end connected to a grounding element. This is intended to provide protection from electromagnetic interference. Such systems reduce the electromagnetically induced voltage in a shielded conductor. This is intended to provide protection against induced electromagnetic interference from lightning. This network provides a normally-high impedance which breaks down to a very low impedance in response to a momentary voltage surge electromagnetically induced in the shield. This establishes a conductive path between the shield and ground. Any surge voltage from lightning creates a current through the cable. This results in an electromagnetic field of the opposite direction, which cancels or reduces the magnitude of the electromagnetic field within the shielded cable.

Watercraft Protectors


A lightning protection installation on a watercraft comprises a lightning protector mounted on the top of a mast or superstructure, and a grounding conductor in contact with the water. Electrical conductors attach to the protector and run down to the conductor. For a vessel with a conducting (iron or steel) hull, the grounding conductor is the hull. For a vessel with a non-conducting hull, the grounding conductor may be retractable, attached to the hull, or attached to a centerboard.

Risk Assessment


Some structures are inherently more or less at risk of being struck by lightning. The risk for a structure is a function of the size (area) of a structure, the height, and the number of lightning strikes per year per mi² for the region. For example, a small building will be less likely to be struck than a large one, and a building in an area with a high density of lightning strikes will be more likely to be struck than one in an area with a low density of lightning strikes. The National Fire Protection Association provides a risk assessment worksheet in their lightning protection standard.

The International Electrotechnical Commission (IEC) lightning risk-assessment comprises four parts: loss of living beings, loss of service to public, loss of cultural heritage, and loss of economic value. Loss of living beings is rated as the most important and is the only loss taken into consideration for many nonessential industrial and commercial applications.

Standards


Several lightning protection masts can be seen in the background of this photo of a rocket launch site.

The introduction of lightning protection systems into standards allowed various manufactures to develop protector systems to a multitude of specifications. There are multiple international, national, corporate and military lightning protection standards.

  • NFPA-780: “Standard for the Installation of Lightning Protection Systems” (2014)
  • M440.1-1, Electrical Storms and Lightning Protection, Department of Energy
  • AFI 32-1065 – Grounding Systems, U. S. Air Force Space Command
  • FAA STD 019e, Lightning and Surge Protection, Grounding, Bonding and Shielding Requirements for Facilities and Electronic Equipment
  • UL standards for lightning protection
    • UL 96: “Standard of Lightning Protection Components” (5th Edition, 2005)
    • UL 96A: “Standard for Installation Requirements for Lightning Protection Systems” (Twelfth Edition, 2007)
    • UL 1449: “Standard for Surge Protective Devices” (Fourth Edition, 2014)
  • IEC standards
    • EN 61000-4-5/IEC 61000-4-5: “Electromagnetic compatibility (EMC) – Part 4-5: Testing and measurement techniques – Surge immunity test”
    • EN 62305/IEC 62305: “Protection against lightning”
    • EN 62561/IEC 62561: “Lightning Protection System Components (LPSC)”
  • ITU-T K Series recommendations: “Protection against interference”
  • IEEE standards for grounding
    • IEEE SA-142-2007: “IEEE Recommended Practice for Grounding of Industrial and Commercial Power Systems.” (2007)
    • IEEE SA-1100-2005: “IEEE Recommended Practice for Powering and Grounding Electronic Equipment” (2005)
  • AFNOR NF C 17-102: “Lightning protection – Protection of structures and open areas against lightning using early streamer emission air terminals” (1995)