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Murray Campbell

(b Paris, Nov 16, 1866; d Toulouse, Nov 15, 1953). French physicist and acoustician. He studied physics at the Sorbonne (1883) and at the Ecole Normale Supérieure (1885–8). After teaching at the Collège de France and the Lycée at Agen, in ...

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Murray Campbell

(b London, August 26, 1933). English physicist and acoustician. He obtained a BSc in physics from Imperial College, London, later gaining the doctorate there with research into high-amplitude stress waves. After holding a research fellowship at the electronic music laboratory of the Canadian National Research Council in Ottawa, he worked for five years in the acoustics section of the UK National Physical Laboratory, where he carried out research on the psycho-acoustic perception of short duration and very low frequency sounds. In ...

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C. Truesdell and Clive Greated

(b Wittenberg, Nov 30, 1756; d Breslau [now Wrocław], April 3, 1827). German acoustician. He studied law at Leipzig University before turning to scientific studies. He invented two instruments, the ‘euphon’ and the ‘klavizylinder’, both of which were variants of the glass harmonica. However, he owes his fame to his celebrated experiments on the nodal patterns and corresponding frequencies of vibration plates. He showed that the vibration patterns, often called Chladni figures, could be made visible by sprinkling sand on the plate. The sand is thrown up on vibrating areas and collects around nodal lines. Chladni travelled through Europe playing on his instruments and demonstrating his experiments before many persons and institutions; he encountered Goethe, Lichtenberg, Olbers, Laplace, Napoleon and other notable men of the period. Chladni's experiments stimulated much early work on the vibration of plates and bars and indeed so impressed the Académie des Sciences, Paris, that it offered a prize for a successful explanation of his sand figures and the motion of elastic surfaces in general. His work helped to form the foundation of modern theories, capable of predicting precise vibration patterns for violin and guitar top plates and the soundboards of keyboard instruments....

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Murray Campbell

(b Munich, Aug 16, 1905; d Miesbach, Oct 16, 1990). German acoustician. He studied mechanical and electrical engineering at the Technical University of Berlin, gaining his doctorate in 1932 for a thesis on sound absorption by porous surfaces. Cremer subsequently engaged in acoustical research at the Technical University and the Heinrich Hertz Institute in Berlin. In ...

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Clive Greated

(b Basle, April 4, 1707; d St Petersburg, Sept 18, 1783). Swiss mathematician, scientist and philosopher. He studied at Basle University under Johann Bernoulli. When he was 20, he took (at Daniel Bernoulli's suggestion) a post at the Academy of Sciences in St Petersburg; he held a post in Berlin (...

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James F. Bell and Clive Greated

(b Potsdam, Aug 31, 1821; d Berlin, Sept 8, 1894). German scientist. He studied medicine at the Friedrich-Wilhelm Institut, Berlin, obtaining the doctorate in 1842. He also studied mathematics, physics and philosophy, and attended lectures at Berlin University. After service as an army surgeon, in ...

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Clive Greated

(b Freshwater, Isle of Wight, July 18, 1635; d London, March 3, 1702). English physicist. He was educated at Westminster School and at Christ Church, Oxford, where he encountered leading natural philosophers associated with empirical learning, including Robert Boyle, whose assistant he became. In ...

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James F. Bell and Clive Greated

(b Königsberg, Nov 26, 1832; d Paris, Oct 2, 1901). German physicist. Although Helmholtz was his principal professor at the University of Königsberg, Koenig's research was not in acoustics. After receiving the PhD in physics, Koenig apprenticed himself to the Parisian violin maker Vuillaume. Koenig completed his apprenticeship in ...

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(b Turin, Jan 25, 1736; d Paris, April 10, 1813). French mathematician and physicist. He was largely self-trained and was encouraged by Euler and d'Alembert, whose protégé he became. He held positions in Berlin (from 1766) and Paris (from 1787). He is remembered as an acoustician for his work in ...

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Murray Campbell

(b Mulhouse, ?Aug 26, 1728; d Berlin, Sept 25, 1777). German scientist. From 1748 to 1758 he was tutor to the children of a Swiss noble family; in 1765 he managed to obtain a post at the Akademie der Wissenschaften in Berlin. He was one of those universal scientists characteristic of the 17th and 18th centuries, and was a figure of particular importance in several subjects mainly connected with physics and mathematics. He determined very precisely the frequencies of the first eight overtones of a bar in its clamped-free modes, correcting and extending Euler’s results; the results of Rayleigh and others, a century or more later, were less conclusive. Lambert projected a musical instrument, the ‘musique solitaire’, whereby a person might enjoy music through his teeth without awakening sleepers....

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Hans Heinrich Eggebrecht

(b Dresden, June 18, 1909; d Bad Reichenhall, June 13, 1997). German acoustician. After attending the Technische Hochschule in Dresden (1928–9), he studied at the universities of Kiel, Tübingen and Berlin (where he was a pupil of Biehle). His work with M. Grützmacher and Gurlitt during this period stimulated his later research. In ...

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Murray Campbell

(b Brunswick, March 16, 1933). German acoustician. In 1957 he enrolled in the Technical University of Brunswick as a student of electronics and music, becoming a research scientist in the acoustics laboratory at the Physikalisch-Technische Bundesanstalt in Brunswick in 1958. In 1960 he was awarded the doctorate by the Technical University for a dissertation on the behaviour of organ flue pipes, supervised by Martin Grützmacher. Meyer was appointed head of the acoustics laboratory in ...

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Murray Campbell and Clive Greated

(b Schiebroek, Netherlands, July 31, 1932). Dutch physicist and acoustician. At Delft University he obtained a degree in technical physics (1956) and took the PhD (1969). The major part of his professional career has been spent at TNO (Netherlands Organization for Applied Scientific Research). He is an accomplished jazz clarinettist. His most important contribution has been to the fundamental acoustics of woodwind instruments. In aiming to find more rational design procedures, he has made a comprehensive theoretical analysis of the resonance of tubes, incorporating the effects of side holes, bends, mouthpieces and reeds. This allows detailed calculations to be made of the hole positions in a woodwind instrument and predictions to be made about aspects of tuning and tone quality. His findings are presented in ...

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James F. Bell and Murray Campbell

(b Erlangen, March 16, 1789; d Munich, July 6, 1854). German scientist. He studied mathematics at the University of Erlangen, taking a degree in 1811. He spent the rest of his life in a series of undistinguished posts, teaching mathematics and later physics at a relatively elementary level, apart from a period (...

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R.W.B. Stephens and Murray Campbell

(b Langford Grove, nr Maldon, Essex, Nov 12, 1842; d Witham, Essex, June 30, 1919). English scientist. He was educated at Cambridge University, where he was Cavendish Professor of Experimental Physics (1879–84); later (1887–1905) he held the professorship of natural philosophy at the Royal Institution, London, and in ...

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Mark Lindley

(b Montpellier, Sept 14, 1723; d Montpellier, Nov 8, 1766). French dilettante and scientist. In December 1751 he announced his discovery of difference tones, which he had made by experiments with wind instruments. (Nearly three years later Tartini, evidently unaware of Romieu’s work, published his discovery of the same phenomenon observed in double stops on the violin.) Romieu’s ‘Mémoire théorique & practique sur les systèmes temperés de musique’, published in the ...

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C. Truesdell and Murray Campbell

(b La Flèche, March 24, 1653; d Paris, July 9, 1716). French acoustician. In 1670 he went to Paris, where he attended the lectures of the Cartesian physicist Rohault; his works do not display the knowledge of advanced mathematics that characterizes the scientific progress of the age of Newton, although he held a chair of mathematics for a decade. He was elected to membership of the Académie des Sciences (...

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James F. Bell, R.W.B. Stephens and Murray Campbell

(b Mézières, June 30, 1791; d Paris, March 16, 1841). French scientist. He was trained at Strasbourg in medicine, taking a degree in 1816. He had long been interested in acoustics when, in 1816, he abandoned medicine and went to Paris, where he came under the guidance of Biot. He became a professor of natural philosophy in ...

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Murray Campbell

(b Gainsborough, 1689; d Cambridge, 1768). English mathematician. He entered Trinity College, Cambridge, in 1708, and became a senior Fellow in 1739 and Master in 1742; he was also a Fellow of the Royal Society and Plumian Professor of Astronomy (1716–60). His work on acoustics is contained in ...

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Murray Campbell

(b Hull, August 14, 1922; d March 7, 2002). English physicist, writer and lecturer on the physics of music. He studied physics at Queen Mary College, London (BSc 1942), and at the University of Manchester Institute of Science and Technology (PhD 1951...