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41 De Forest, Lee
SUBJECT AREA: Broadcasting, Electronics and information technology, Photography, film and optics, Recording, Telecommunications[br]b. 26 August 1873 Council Bluffs, Iowa, USAd. 30 June 1961 Hollywood, California, USA[br]American electrical engineer and inventor principally known for his invention of the Audion, or triode, vacuum tube; also a pioneer of sound in the cinema.[br]De Forest was born into the family of a Congregational minister that moved to Alabama in 1879 when the father became President of a college for African-Americans; this was a position that led to the family's social ostracism by the white community. By the time he was 13 years old, De Forest was already a keen mechanical inventor, and in 1893, rejecting his father's plan for him to become a clergyman, he entered the Sheffield Scientific School of Yale University. Following his first degree, he went on to study the propagation of electromagnetic waves, gaining a PhD in physics in 1899 for his thesis on the "Reflection of Hertzian Waves from the Ends of Parallel Wires", probably the first US thesis in the field of radio.He then joined the Western Electric Company in Chicago where he helped develop the infant technology of wireless, working his way up from a modest post in the production area to a position in the experimental laboratory. There, working alone after normal working hours, he developed a detector of electromagnetic waves based on an electrolytic device similar to that already invented by Fleming in England. Recognizing his talents, a number of financial backers enabled him to set up his own business in 1902 under the name of De Forest Wireless Telegraphy Company; he was soon demonstrating wireless telegraphy to interested parties and entering into competition with the American Marconi Company.Despite the failure of this company because of fraud by his partners, he continued his experiments; in 1907, by adding a third electrode, a wire mesh, between the anode and cathode of the thermionic diode invented by Fleming in 1904, he was able to produce the amplifying device now known as the triode valve and achieve a sensitivity of radio-signal reception much greater than possible with the passive carborundum and electrolytic detectors hitherto available. Patented under the name Audion, this new vacuum device was soon successfully used for experimental broadcasts of music and speech in New York and Paris. The invention of the Audion has been described as the beginning of the electronic era. Although much development work was required before its full potential was realized, the Audion opened the way to progress in all areas of sound transmission, recording and reproduction. The patent was challenged by Fleming and it was not until 1943 that De Forest's claim was finally recognized.Overcoming the near failure of his new company, the De Forest Radio Telephone Company, as well as unsuccessful charges of fraudulent promotion of the Audion, he continued to exploit the potential of his invention. By 1912 he had used transformer-coupling of several Audion stages to achieve high gain at radio frequencies, making long-distance communication a practical proposition, and had applied positive feedback from the Audion output anode to its input grid to realize a stable transmitter oscillator and modulator. These successes led to prolonged patent litigation with Edwin Armstrong and others, and he eventually sold the manufacturing rights, in retrospect often for a pittance.During the early 1920s De Forest began a fruitful association with T.W.Case, who for around ten years had been working to perfect a moving-picture sound system. De Forest claimed to have had an interest in sound films as early as 1900, and Case now began to supply him with photoelectric cells and primitive sound cameras. He eventually devised a variable-density sound-on-film system utilizing a glow-discharge modulator, the Photion. By 1926 De Forest's Phonofilm had been successfully demonstrated in over fifty theatres and this system became the basis of Movietone. Though his ideas were on the right lines, the technology was insufficiently developed and it was left to others to produce a system acceptable to the film industry. However, De Forest had played a key role in transforming the nature of the film industry; within a space of five years the production of silent films had all but ceased.In the following decade De Forest applied the Audion to the development of medical diathermy. Finally, after spending most of his working life as an independent inventor and entrepreneur, he worked for a time during the Second World War at the Bell Telephone Laboratories on military applications of electronics.[br]Principal Honours and DistinctionsInstitute of Electronic and Radio Engineers Medal of Honour 1922. President, Institute of Electronic and Radio Engineers 1930. Institute of Electrical and Electronics Engineers Edison Medal 1946.Bibliography1904, "Electrolytic detectors", Electrician 54:94 (describes the electrolytic detector). 1907, US patent no. 841,387 (the Audion).1950, Father of Radio, Chicago: WIlcox \& Follett (autobiography).De Forest gave his own account of the development of his sound-on-film system in a series of articles: 1923. "The Phonofilm", Transactions of the Society of Motion Picture Engineers 16 (May): 61–75; 1924. "Phonofilm progress", Transactions of the Society of Motion Picture Engineers 20:17–19; 1927, "Recent developments in the Phonofilm", Transactions of the Society of Motion Picture Engineers 27:64–76; 1941, "Pioneering in talking pictures", Journal of the Society of Motion Picture Engineers 36 (January): 41–9.Further ReadingG.Carneal, 1930, A Conqueror of Space (biography).I.Levine, 1964, Electronics Pioneer, Lee De Forest (biography).E.I.Sponable, 1947, "Historical development of sound films", Journal of the Society of Motion Picture Engineers 48 (April): 275–303 (an authoritative account of De Forest's sound-film work, by Case's assistant).W.R.McLaurin, 1949, Invention and Innovation in the Radio Industry.C.F.Booth, 1955, "Fleming and De Forest. An appreciation", in Thermionic Valves 1904– 1954, IEE.V.J.Phillips, 1980, Early Radio Detectors, London: Peter Peregrinus.KF / JW -
42 Parker, George Safford
SUBJECT AREA: Paper and printing[br]b. 1 November 1863 Shullsberg, Wisconsin, USAd. 19 July 1937 USA[br]American perfector of the fountain pen and founder of the Parker Pen Company.[br]Parker was born of English immigrant stock and grew up on his parents' farm in Iowa. He matriculated at Upper Iowa University and then joined the Valentine School of Telegraphy at Jamesville, Wisconsin: within a year he was on the staff. He supplemented his meagre school-master's pay by selling fountain pens to his students. He found that the pens needed constant attention, and his students were continually bringing them back to him for repair. The more he sold, the more he repaired. The work furnished him, first, with a detailed knowledge of the design and construction of the fountain pen and then with the thought that he could make a better pen himself. He gave up his teaching career and in 1888 began experimenting. He established his own company and in the following year he registered his first patent. The Parker Pen Company was formally incorporated on 8 March 1892.In the following years he patented many improvements, including the Lucky Curve pen and ink-feed system, patented in 1894. That was the real breakthrough for Parker and the pen was an immediate success. It solved the problem that had bedevilled the fountain pen before and since, by incorporating an ink-feed system that ensured a free and uniform flow of ink to where it was wanted, the nib, and not to other undesirable places.Parker established a reputation for manufacturing high-quality pens that looked good and worked well and reliably. The pens were in demand worldwide and the company grew.During the First World War, Parker introduced the Trench Pen for use on the Western Front. A tablet of pigment was inserted in a blind cap at the end of the pen. When this tablet was placed in the barrel and the barrel was filled with water, the pen was ready for use.Later developments included the Duofold pen, designed and launched in 1920. It had an enlarged ink capacity, a red barrel and a twentyfive-year guarantee on the nib. It became immensely popular with the public and was the flagship product throughout the 1920s and early 1930s, until the Vacumatic was launched in 1933.Parker handed over control of the company to this two sons, Kenneth and Russell, during the 1920s, remaining President until his retirement in 1933.[br]Further ReadingObituary, 1937, Jamesville Gazette 19 July (an appreciation by the architect Frank Lloyd Wright was published simultaneously). No biography has appeared, but Parker gave details of his career in an article in SystemsReview, October 1926.LRD -
43 Stevenson, Robert
[br]b. 8 June 1772 Glasgow, Scotlandd. 12 July 1850 Edinburgh, Scotland[br]Scottish lighthouse designer and builder.[br]After his father's death when he was only 2 years old, Robert Stevenson was educated at a school for children from families in reduced circumstances. However, c. 1788 his mother married again, to Thomas Smith, Engineer to the Northern Lighthouse Board. Stevenson then served an apprenticeship under his new stepfather. The Board, which is still an active force in the 1990s, was founded in 1786 to oversee the lights and buoyage in some of the wildest waters in Western Europe, the seas around the coasts of Scotland and the Isle of Man.After studies at Andersen's College (now the University of Strathclyde) and later at Edinburgh University, Stevenson assumed responsibility in the field for much of the construction work sanctioned by the Board. After some years he succeeded Smith as Engineer to the Board and thereby the long connection between the Northern Lights and the Stevenson family commenced.Stevenson became Engineer to the Board when he was about 30 years old, remaining in that office for the best part of half a century. During these years he improved catoptric lighting, adopted the central lamp refracting system and invented the intermittent flashing light. While these developments were sufficient to form a just memorial to the man, he was involved in greater endeavours in the construction of around twenty lighthouses, most of which had ingenious forms of construction. The finest piece was the Bell Rock Lighthouse, built on a reef off the Scottish East Coast. This enterprise took five years to complete and can be regarded as the most important construction of his life.His interests fitted in with those of the other great men living in and around Edinburgh at the time, and included oceanography, astronomy, architecture and antiquarian studies. He designed several notable bridges, proposed a design for the rails for railways and also made a notable study of marine timber borers. He contributed to Encyclopaedia Britannica and to many journals.His grandson, born in the year of his death, was the famous author Robert Louis Stevenson (1850–94).[br]Principal Honours and DistinctionsFRS Edinburgh.Further ReadingSir Walter Scott, 1982, Northern Lights, Hawick.FMW
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