electrical patent

1) патент (охранный документ на изобретение, удостоверяющий признание предложения изобретением, его приоритет и исключительное право на него патентообладателя)

2) патентовать; патентованный; патентный

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- patent alleged to be infringed

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1) пат., юр. патент (охранный документ на изобретение, удостоверяющий признание предложения изобретением, его приоритет и исключительное право на него патентообладателя)

2) пат., юр. патентное право (исключительное право на интеллектуальную собственность, получаемое благодаря патенту)

1) общ. явный, очевидный

2) пат., юр. патентованный, запатентованный ( защищенный патентом)

пат., юр. патентовать, получать патент

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உலோகத் தகடு, (தொழில் நுட்பம்) வடிவமைப்பு

உரிமைக்காப்பு

தனியுரிமைச் சான்றிதழ்; தெளிவான; தனியுரிமைச் சான்றுடைய; உரிமைக் காப்புடைய

திறந்த

தடையின்றி திறந்துள்ள, திறந்துள்ள, அடைபடாமல், சான்றாக

தனிக் காப்புரிமை / தெளிவாகத் தோன்றுகிற, புனைவுரிமை

ஆக்கவுரிமை

உலோகத் தகடு

(தொழில் நுட்பம்) வடிவமைப்பு

பட்டயம்

1) уполномоченный; доверенный

2) поверенный; юрист, адвокат

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- attorney at law

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SUBJECT AREA: Horology, Telecommunications

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Alexander Bain was born into a crofting family in a remote part of Scotland. He was apprenticed to a watchmaker in Wick and during that time he was strongly influenced by a lecture on "Heat, sound and electricity" that he heard in nearby Thurso. This lecture induced him to take up a position in Clerkenwell in London, working as a journeyman clockmaker, where he was able to further his knowledge of electricity by attending lectures at the Adelaide Gallery and the Polytechnic Institution. His thoughts naturally turned to the application of electricity to clockmaking, and despite a bitter dispute with Charles Wheatstone over priority he was granted the first British patent for an electric clock. This patent, taken out on 11 January 1841, described a mechanism for an electric clock, in which an oscillating component of the clock operated a mechanical switch that initiated an electromagnetic pulse to maintain the regular, periodic motion. This principle was used in his master clock, produced in 1845. On 12 December of the same year, he patented a means of using electricity to control the operation of steam railway engines via a steam-valve. His earliest patent was particularly far-sighted and anticipated most of the developments in electrical horology that occurred during the nineteenth century. He proposed the use of electricity not only to drive clocks but also to distribute time over a distance by correcting the hands of mechanical clocks, synchronizing pendulums and using slave dials (here he was anticipated by Steinheil). However, he was less successful in putting these ideas into practice, and his electric clocks proved to be unreliable. Early electric clocks had two weaknesses: the battery; and the switching mechanism that fed the current to the electromagnets. Bain's earth battery, patented in 1843, overcame the first defect by providing a reasonably constant current to drive his clocks, but unlike Hipp he failed to produce a reliable switch.

The application of Bain's numerous patents for electric telegraphy was more successful, and he derived most of his income from these. They included a patent of 12 December 1843 for a form of fax machine, a chemical telegraph that could be used for the transmission of text and of images (facsimile). At the receiver, signals were passed through a moving band of paper impregnated with a solution of ammonium nitrate and potassium ferrocyanide. For text, Morse code signals were used, and because the system could respond to signals faster than those generated by hand, perforated paper tape was used to transmit the messages; in a trial between Paris and Lille, 282 words were transmitted in less than one minute. In 1865 the Abbé Caselli, a French engineer, introduced a commercial fax service between Paris and Lyons, based on Bain's device. Bain also used the idea of perforated tape to operate musical wind instruments automatically. Bain squandered a great deal of money on litigation, initially with Wheatstone and then with Morse in the USA. Although his inventions were acknowledged, Bain appears to have received no honours, but when towards the end of his life he fell upon hard times, influential persons in 1873 secured for him a Civil List Pension of £80 per annum and the Royal Society gave him £150.

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See also: Bakewell, Frederick C.

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SUBJECT AREA: Electricity, Photography, film and optics

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At the age of 14 Swan was apprenticed to a Sunderland firm of druggists, later joining John Mawson who had opened a pharmacy in Newcastle. While in Sunderland Swan attended lectures at the Athenaeum, at one of which W.E. Staite exhibited electric-arc and incandescent lighting. The impression made on Swan prompted him to conduct experiments that led to his demonstration of a practical working lamp in 1879. As early as 1848 he was experimenting with carbon as a lamp filament, and by 1869 he had mounted a strip of carbon in a vessel exhausted of air as completely as was then possible; however, because of residual air, the filament quickly failed.

Discouraged by the cost of current from primary batteries and the difficulty of achieving a good vacuum, Swan began to devote much of his attention to photography. With Mawson's support the pharmacy was expanded to include a photographic business. Swan's interest in making permanent photographic records led him to patent the carbon process in 1864 and he discovered how to make a sensitive dry plate in place of the inconvenient wet collodian process hitherto in use. He followed this success with the invention of bromide paper, the subject of a British patent in 1879.

Swan resumed his interest in electric lighting. Sprengel's invention of the mercury pump in 1865 provided Swan with the means of obtaining the high vacuum he needed to produce a satisfactory lamp. Swan adopted a technique which was to become an essential feature in vacuum physics: continuing to heat the filament during the exhaustion process allowed the removal of absorbed gases. The inventions of Gramme, Siemens and Brush provided the source of electrical power at reasonable cost needed to make the incandescent lamp of practical service. Swan exhibited his lamp at a meeting in December 1878 of the Newcastle Chemical Society and again the following year before an audience of 700 at the Newcastle Literary and Philosophical Society. Swan's failure to patent his invention immediately was a tactical error as in November 1879 Edison was granted a British patent for his original lamp, which, however, did not go into production. Parchmentized thread was used in Swan's first commercial lamps, a material soon superseded by the regenerated cellulose filament that he developed. The cellulose filament was made by extruding a solution of nitro-cellulose in acetic acid through a die under pressure into a coagulating fluid, and was used until the ultimate obsolescence of the carbon-filament lamp. Regenerated cellulose became the first synthetic fibre, the further development and exploitation of which he left to others, the patent rights for the process being sold to Courtaulds.

Swan also devised a modification of Planté's secondary battery in which the active material was compressed into a cellular lead plate. This has remained the central principle of all improvements in secondary cells, greatly increasing the storage capacity for a given weight.

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SUBJECT AREA: Electricity, Electronics and information technology, Public utilities

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After attending Owens College, Manchester, Hopkinson was admitted to Trinity College, Cambridge, in 1867 to read for the Mathematical Tripos. An appointment in 1872 with the lighthouse department of the Chance Optical Works in Birmingham directed his attention to electrical engineering. His most noteworthy contribution to lighthouse engineering was an optical system to produce flashing lights that distinguished between individual beacons. His extensive researches on the dielectric properties of glass were recognized when he was elected to a Fellowship of the Royal Society at the age of 29. Moving to London in 1877 he became established as a consulting engineer at a time when electricity supply was about to begin on a commercial scale. During the remainder of his life, Hopkinson's researches resulted in fundamental contributions to electrical engineering practice, dynamo design and alternating current machine theory. In making a critical study of the Edison dynamo he developed the principle of the magnetic circuit, a concept also arrived at by Gisbert Kapp around the same time. Hopkinson's improvement of the Edison dynamo by reducing the length of the field magnets almost doubled its output. In 1890, in addition to-his consulting practice, Hopkinson accepted a post as the first Professor of Electrical Engineering and Head of the Siemens laboratory recently established at King's College, London. Although he was not involved in lecturing, the position gave him the necessary facilities and staff and student assistance to continue his researches. Hopkinson was consulted on many proposals for electric traction and electricity supply, including schemes in London, Manchester, Liverpool and Leeds. He also advised Mather and Platt when they were acting as contractors for the locomotives and generating plant for the City and South London tube railway. As early as 1882 he considered that an ideal method of charging for the supply of electricity should be based on a two-part tariff, with a charge related to maximum demand together with a charge for energy supplied. Hopkinson was one the foremost expert witnesses of his day in patent actions and was himself the patentee of over forty inventions, of which the three-wire system of distribution and the series-parallel connection of traction motors were his most successful. Jointly with his brother Edward, John Hopkinson communicated the outcome of his investigations to the Royal Society in a paper entitled "Dynamo Electric Machinery" in 1886. In this he also described the later widely used "back to back" test for determining the characteristics of two identical machines. His interest in electrical machines led him to more fundamental research on magnetic materials, including the phenomenon of recalescence and the disappearance of magnetism at a well-defined temperature. For his work on the magnetic properties of iron, in 1890 he was awarded the Royal Society Royal Medal. He was a member of the Alpine Club and a pioneer of rock climbing in Britain; he died, together with three of his children, in a climbing accident.

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SUBJECT AREA: Electricity

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When he was 14 years old Davenport was apprenticed to a blacksmith for seven years. At the close of his apprenticeship in 1823 he opened a blacksmith's shop in Brandon, Vermont. He began experimenting with electromagnets after observing one in use at the Penfield Iron Works at Crown Point, New York, in 1831. He saw the device as a possible source of power and by July 1834 had constructed his first electric motor. Having totally abandoned his regular business, Davenport built and exhibited a number of miniature machines; he utilized an electric motor to propel a model car around a circular track in 1836, and this became the first recorded instance of an electric railway. An application for a patent and a model were destroyed in a fire at the United States Patent Office in December 1836, but a second application was made and Davenport received a patent the following year for Improvements in Propelling Machinery by Magnetism and Electromagnetism. A British patent was also obtained. A workshop and laboratory were established in New York, but Davenport had little financial backing for his experiments. He built a total of over one hundred motors but was defeated by the inability to obtain an inexpensive source of power. Using an electric motor of his own design to operate a printing press in 1840, he undertook the publication of a journal, The Electromagnet and Mechanics' Intelligencer. This was the first American periodical on electricity, but it was discontinued after a few issues. In failing health he retired to Vermont where in the last year of his life he continued experiments in electromagnetism.

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SUBJECT AREA: Telecommunications

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At the age of 15 years Bright left the London Merchant Taylors' School to join the two-year-old Electric Telegraph Company. By 1851 he was in charge of the Birmingham telegraph station. After a short time as Assistant Engineer with the newly formed British Telegraph Company, he joined his brother (who was Manager) as Engineer-in-Chief of the English and Irish Magnetic Telegraph Company in Liverpool, for which he laid thousands of miles of underground cable and developed a number of innovations in telegraphy including a resistance box for locating cable faults and a two-tone bell system for signalling. In 1853 he was responsible for the first successful underwater cable between Scotland and Ireland. Three years later, with the American financier Cyrus Field and John Brett, he founded and was Engineer-in-chief of the Atlantic Telegraph Company, which aimed at laying a cable between Ireland and Newfoundland. After several unsuccessful attempts this was finally completed on 5 August 1858, Bright was knighted a month later, but the cable then failed! In 1860 Bright resigned from the Magnetic Telegraph Company to set up an independent consultancy with another engineer, Joseph Latimer Clark, with whom he invented an improved bituminous cable insulation. Two years later he supervised construction of a telegraph cable to India, and in 1865 a further attempt to lay an Atlantic cable using Brunel's new ship, the Great Eastern. This cable broke during laying, but in 1866 a new cable was at last successfully laid and the 1865 cable recovered and repaired. The year 1878 saw extension of the Atlantic cable system to the West Indies and the invention with his brother of a system of neighbourhood fire alarms and even an automatic fire alarm.

In 1861 Bright presented a paper to the British Association for the Advancement of Science on the need for electrical standards, leading to the creation of an organization that still exists in the 1990s. From 1865 until 1868 he was Liberal MP for Greenwich, and he later assisted with preparations for the 1881 Paris Exhibition.

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SUBJECT AREA: Electricity, Public utilities

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Ferranti, who had taken an interest in electrical and mechanical devices from an early age, was educated at St Augustine's College in Ramsgate and for a short time attended evening classes at University College, London. Rather than pursue an academic career, Ferranti, who had intense practical interests, found employment in 1881 with the Siemens Company (see Werner von Siemens) in their experimental department. There he had the opportunity to superintend the installation of electric-lighting plants in various parts of the country. Becoming acquainted with Alfred Thomson, an engineer, Ferranti entered into a short-lived partnership with him to manufacture the Ferranti alternator. This generator, with a unique zig-zag armature, had an efficiency exceeding that of all its rivals. Finding that Sir William Thomson had invented a similar machine, Ferranti formed a company with him to combine the inventions and produce the Ferranti- Thomson machine. For this the Hammond Electric Light and Power Company obtained the sole selling rights.

In 1885 the Grosvenor Gallery Electricity Supply Corporation was having serious problems with its Gaulard and Gibbs series distribution system. Ferranti, when consulted, reviewed the design and recommended transformers connected across constant-potential mains. In the following year, at the age of 22, he was appointed Engineer to the company and introduced the pattern of electricity supply that was eventually adopted universally. Ambitious plans by Ferranti for London envisaged the location of a generating station of unprecedented size at Deptford, about eight miles (13 km) from the city, a departure from the previous practice of placing stations within the area to be supplied. For this venture the London Electricity Supply Corporation was formed. Ferranti's bold decision to bring the supply from Deptford at the hitherto unheard-of pressure of 10,000 volts required him to design suitable cables, transformers and generators. Ferranti planned generators with 10,000 hp (7,460 kW)engines, but these were abandoned at an advanced stage of construction. Financial difficulties were caused in part when a Board of Trade enquiry in 1889 reduced the area that the company was able to supply. In spite of this adverse situation the enterprise continued on a reduced scale. Leaving the London Electricity Supply Corporation in 1892, Ferranti again started his own business, manufacturing electrical plant. He conceived the use of wax-impregnated paper-insulated cables for high voltages, which formed a landmark in the history of cable development. This method of flexible-cable manufacture was used almost exclusively until synthetic materials became available. In 1892 Ferranti obtained a patent which set out the advantages to be gained by adopting sector-shaped conductors in multi-core cables. This was to be fundamental to the future design and development of such cables.

A total of 176 patents were taken out by S.Z. de Ferranti. His varied and numerous inventions included a successful mercury-motor energy meter and improvements to textile-yarn produc-tion. A transmission-line phenomenon where the open-circuit voltage at the receiving end of a long line is greater than the sending voltage was named the Ferranti Effect after him.

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SUBJECT AREA: Architecture and building, Automotive engineering, Electricity, Electronics and information technology, Metallurgy, Photography, film and optics, Public utilities, Recording, Telecommunications

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He was the son of Samuel Edison, who was in the timber business. His schooling was delayed due to scarlet fever until 1855, when he was 8½ years old, but he was an avid reader. By the age of 14 he had a job as a newsboy on the railway from Port Huron to Detroit, a distance of sixty-three miles (101 km). He worked a fourteen-hour day with a stopover of five hours, which he spent in the Detroit Free Library. He also sold sweets on the train and, later, fruit and vegetables, and was soon making a profit of $20 a week. He then started two stores in Port Huron and used a spare freight car as a laboratory. He added a hand-printing press to produce 400 copies weekly of The Grand Trunk Herald, most of which he compiled and edited himself. He set himself to learn telegraphy from the station agent at Mount Clements, whose son he had saved from being run over by a freight car.

At the age of 16 he became a telegraphist at Port Huron. In 1863 he became railway telegraphist at the busy Stratford Junction of the Grand Trunk Railroad, arranging a clock with a notched wheel to give the hourly signal which was to prove that he was awake and at his post! He left hurriedly after failing to hold a train which was nearly involved in a head-on collision. He usually worked the night shift, allowing himself time for experiments during the day. His first invention was an arrangement of two Morse registers so that a high-speed input could be decoded at a slower speed. Moving from place to place he held many positions as a telegraphist. In Boston he invented an automatic vote recorder for Congress and patented it, but the idea was rejected. This was the first of a total of 1180 patents that he was to take out during his lifetime. After six years he resigned from the Western Union Company to devote all his time to invention, his next idea being an improved ticker-tape machine for stockbrokers. He developed a duplex telegraphy system, but this was turned down by the Western Union Company. He then moved to New York.

Edison found accommodation in the battery room of Law's Gold Reporting Company, sleeping in the cellar, and there his repair of a broken transmitter marked him as someone of special talents. His superior soon resigned, and he was promoted with a salary of $300 a month. Western Union paid him $40,000 for the sole rights on future improvements on the duplex telegraph, and he moved to Ward Street, Newark, New Jersey, where he employed a gathering of specialist engineers. Within a year, he married one of his employees, Mary Stilwell, when she was only 16: a daughter, Marion, was born in 1872, and two sons, Thomas and William, in 1876 and 1879, respectively.

He continued to work on the automatic telegraph, a device to send out messages faster than they could be tapped out by hand: that is, over fifty words per minute or so. An earlier machine by Alexander Bain worked at up to 400 words per minute, but was not good over long distances. Edison agreed to work on improving this feature of Bain's machine for the Automatic Telegraph Company (ATC) for $40,000. He improved it to a working speed of 500 words per minute and ran a test between Washington and New York. Hoping to sell their equipment to the Post Office in Britain, ATC sent Edison to England in 1873 to negotiate. A 500-word message was to be sent from Liverpool to London every half-hour for six hours, followed by tests on 2,200 miles (3,540 km) of cable at Greenwich. Only confused results were obtained due to induction in the cable, which lay coiled in a water tank. Edison returned to New York, where he worked on his quadruplex telegraph system, tests of which proved a success between New York and Albany in December 1874. Unfortunately, simultaneous negotiation with Western Union and ATC resulted in a lawsuit.

Alexander Graham Bell was granted a patent for a telephone in March 1876 while Edison was still working on the same idea. His improvements allowed the device to operate over a distance of hundreds of miles instead of only a few miles. Tests were carried out over the 106 miles (170 km) between New York and Philadelphia. Edison applied for a patent on the carbon-button transmitter in April 1877, Western Union agreeing to pay him $6,000 a year for the seventeen-year duration of the patent. In these years he was also working on the development of the electric lamp and on a duplicating machine which would make up to 3,000 copies from a stencil. In 1876–7 he moved from Newark to Menlo Park, twenty-four miles (39 km) from New York on the Pennsylvania Railway, near Elizabeth. He had bought a house there around which he built the premises that would become his "inventions factory". It was there that he began the use of his 200- page pocket notebooks, each of which lasted him about two weeks, so prolific were his ideas. When he died he left 3,400 of them filled with notes and sketches.

Late in 1877 he applied for a patent for a phonograph which was granted on 19 February 1878, and by the end of the year he had formed a company to manufacture this totally new product. At the time, Edison saw the device primarily as a business aid rather than for entertainment, rather as a dictating machine. In August 1878 he was granted a British patent. In July 1878 he tried to measure the heat from the solar corona at a solar eclipse viewed from Rawlins, Wyoming, but his "tasimeter" was too sensitive.

Probably his greatest achievement was "The Subdivision of the Electric Light" or the "glow bulb". He tried many materials for the filament before settling on carbon. He gave a demonstration of electric light by lighting up Menlo Park and inviting the public. Edison was, of course, faced with the problem of inventing and producing all the ancillaries which go to make up the electrical system of generation and distribution-meters, fuses, insulation, switches, cabling—even generators had to be designed and built; everything was new. He started a number of manufacturing companies to produce the various components needed.

In 1881 he built the world's largest generator, which weighed 27 tons, to light 1,200 lamps at the Paris Exhibition. It was later moved to England to be used in the world's first central power station with steam engine drive at Holborn Viaduct, London. In September 1882 he started up his Pearl Street Generating Station in New York, which led to a worldwide increase in the application of electric power, particularly for lighting. At the same time as these developments, he built a 1,300yd (1,190m) electric railway at Menlo Park.

On 9 August 1884 his wife died of typhoid. Using his telegraphic skills, he proposed to 19-year-old Mina Miller in Morse code while in the company of others on a train. He married her in February 1885 before buying a new house and estate at West Orange, New Jersey, building a new laboratory not far away in the Orange Valley.

Edison used direct current which was limited to around 250 volts. Alternating current was largely developed by George Westinghouse and Nicola Tesla, using transformers to step up the current to a higher voltage for long-distance transmission. The use of AC gradually overtook the Edison DC system.

In autumn 1888 he patented a form of cinephotography, the kinetoscope, obtaining film-stock from George Eastman. In 1893 he set up the first film studio, which was pivoted so as to catch the sun, with a hinged roof which could be raised. In 1894 kinetoscope parlours with "peep shows" were starting up in cities all over America. Competition came from the Latham Brothers with a screen-projection machine, which Edison answered with his "Vitascope", shown in New York in 1896. This showed pictures with accompanying sound, but there was some difficulty with synchronization. Edison also experimented with captions at this early date.

In 1880 he filed a patent for a magnetic ore separator, the first of nearly sixty. He bought up deposits of low-grade iron ore which had been developed in the north of New Jersey. The process was a commercial success until the discovery of iron-rich ore in Minnesota rendered it uneconomic and uncompetitive. In 1898 cement rock was discovered in New Village, west of West Orange. Edison bought the land and started cement manufacture, using kilns twice the normal length and using half as much fuel to heat them as the normal type of kiln. In 1893 he met Henry Ford, who was building his second car, at an Edison convention. This started him on the development of a battery for an electric car on which he made over 9,000 experiments. In 1903 he sold his patent for wireless telegraphy "for a song" to Guglielmo Marconi.

In 1910 Edison designed a prefabricated concrete house. In December 1914 fire destroyed three-quarters of the West Orange plant, but it was at once rebuilt, and with the threat of war Edison started to set up his own plants for making all the chemicals that he had previously been buying from Europe, such as carbolic acid, phenol, benzol, aniline dyes, etc. He was appointed President of the Navy Consulting Board, for whom, he said, he made some forty-five inventions, "but they were pigeonholed, every one of them". Thus did Edison find that the Navy did not take kindly to civilian interference.

In 1927 he started the Edison Botanic Research Company, founded with similar investment from Ford and Firestone with the object of finding a substitute for overseas-produced rubber. In the first year he tested no fewer than 3,327 possible plants, in the second year, over 1,400, eventually developing a variety of Golden Rod which grew to 14 ft (4.3 m) in height. However, all this effort and money was wasted, due to the discovery of synthetic rubber.

In October 1929 he was present at Henry Ford's opening of his Dearborn Museum to celebrate the fiftieth anniversary of the incandescent lamp, including a replica of the Menlo Park laboratory. He was awarded the Congressional Gold Medal and was elected to the American Academy of Sciences. He died in 1931 at his home, Glenmont; throughout the USA, lights were dimmed temporarily on the day of his funeral.

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SUBJECT AREA: Electricity, Railways and locomotives

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Page graduated from Harvard in 1832 and subsequently attended Boston Medical School. He began to practise in Salem and also engaged in experimental research in electricity, discovering the improvement effected by substituting bundles of iron wire for solid bars in induction coils. He also created a device which he termed a Dynamic Multiplier, the prototype of the auto-transformer. Following a period in medical practice in Virginia, in 1841 he became one of the first two principal examiners in the United States Patent Office. He also held the Chair of Chemistry and Pharmacy at Columbian College, later George Washington University, between 1844 and 1849.

A prolific inventor, Page completed several large electric motors in which reciprocating action was converted to rotary motion, and invested an extravagant sum of public money in a foredoomed effort to develop a 10-ton electric locomotive powered by primary batteries. This was unsuccessfully demonstrated in April 1851 on the Washington-Baltimore railway and seriously damaged his reputation. Page approached Thomas Davenport with an offer of partnership, but Davenport refused.

After leaving the Patent Office in 1852 he became a patentee himself and advocated the reform of the patent procedures. Page returned to the Patent Office in 1861, and later persuaded Congress to pass a special Act permitting him to patent the induction coil. This was the cause, after his death, of protracted and widely publicized litigation.

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SUBJECT AREA: Electricity, Electronics and information technology, Photography, film and optics

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Paul was educated at the City of London School and Finsbury Technical College. He worked first for a short time in the Bell Telephone Works in Antwerp, Belgium, and then in the electrical instrument shop of Elliott Brothers in the Strand until 1891, when he opened an instrument-making business at 44 Hatton Garden, London. He specialized in the design and manufacture of electrical instruments, including the Ayrton Mather galvanometer. In 1902, with a purpose-built factory, he began large batch production of his instruments. He also opened a factory in New York, where uncalibrated instruments from England were calibrated for American customers. In 1903 Paul introduced the Unipivot galvanometer, in which the coil was supported at the centre of gravity of the moving system on a single pivot. The pivotal friction was less than in a conventional instrument and could be used without accurate levelling, the sensitivity being far beyond that of any pivoted galvanometer then in existence.

In 1894 Paul was asked by two entrepreneurs to make copies of Edison's kinetoscope, the pioneering peep-show moving-picture viewer, which had just arrived in London. Discovering that Edison had omitted to patent the machine in England, and observing that there was considerable demand for the machine from show-people, he began production, making six before the end of the year. Altogether, he made about sixty-six units, some of which were exported. Although Edison's machine was not patented, his films were certainly copyrighted, so Paul now needed a cinematographic camera to make new subjects for his customers. Early in 1895 he came into contact with Birt Acres, who was also working on the design of a movie camera. Acres's design was somewhat impractical, but Paul constructed a working model with which Acres filmed the Oxford and Cambridge Boat Race on 30 March, and the Derby at Epsom on 29 May. Paul was unhappy with the inefficient design, and developed a new intermittent mechanism based on the principle of the Maltese cross. Despite having signed a ten-year agreement with Paul, Acres split with him on 12 July 1895, after having unilaterally patented their original camera design on 27 May. By the early weeks of 1896, Paul had developed a projector mechanism that also used the Maltese cross and which he demonstrated at the Finsbury Technical College on 20 February 1896. His Theatrograph was intended for sale, and was shown in a number of venues in London during March, notably at the Alhambra Theatre in Leicester Square. There the renamed Animatographe was used to show, among other subjects, the Derby of 1896, which was won by the Prince of Wales's horse "Persimmon" and the film of which was shown the next day to enthusiastic crowds. The production of films turned out to be quite profitable: in the first year of the business, from March 1896, Paul made a net profit of £12,838 on a capital outlay of about £1,000. By the end of the year there were at least five shows running in London that were using Paul's projectors and screening films made by him or his staff.

Paul played a major part in establishing the film business in England through his readiness to sell apparatus at a time when most of his rivals reserved their equipment for sole exploitation. He went on to become a leading producer of films, specializing in trick effects, many of which he pioneered. He was affectionately known in the trade as "Daddy Paul", truly considered to be the "father" of the British film industry. He continued to appreciate fully the possibilities of cinematography for scientific work, and in collaboration with Professor Silvanus P.Thompson films were made to illustrate various phenomena to students.

Paul ended his involvement with film making in 1910 to concentrate on his instrument business; on his retirement in 1920, this was amalgamated with the Cambridge Instrument Company. In his will he left shares valued at over £100,000 to form the R.W.Paul Instrument Fund, to be administered by the Institution of Electrical Engineers, of which he had been a member since 1887. The fund was to provide instruments of an unusual nature to assist physical research.

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SUBJECT AREA: Electricity

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After graduating from Keble College, Oxford, Rawcliffe joined the Metropolitan Vickers Electrical Company in 1932 as a college apprentice, and later became a design engineer. This was followed by a period as a lecturer at Liverpool University, where he was able to extend his knowledge of the principles underlying the design and operation of electrical machines. In 1941 he became Head of the Electrical Engineering Department at the Robert Gordon Technical College, Aberdeen, and Lecturer in charge of Electrical Engineering at Aberdeen University. In 1944 Rawcliffe was appointed to the Chair of Electrical Engineering at the University of Bristol, where he remained until his retirement in 1975. The reputation of his department was enhanced by the colleagues he recruited.

After 1954 he began research into polyphase windings, the basis of alternating-current machinery, and published papers concerned with the dual problems of frequency changing and pole changing. The result of this research was the discovery in 1957 of a technique for making squirrel-cage induction motors run at more than one speed. By reversing current in one part of the winding, the pole distribution and number were changed, and with it the speed of rotation.

Rawcliffe's name became synonymous with pole amplitude modulation, or PAM, the name given to this technique. Described by Rawcliffe as a new philosophy of windings, the technique led to a series of research papers, patents and licensing agreements in addition to consultancies to advise on application problems. Commercial exploitation of the new idea throughout Western Europe, the United Kingdom and the United States followed. In total he contributed twentyfive papers to the Proceedings of the Institution of Electrical Engineers and some sixty British patent applications were filed.

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