(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 1848 he obtained a post in physiology and pathology at Königsberg University. Later he held a number of professorships: of anatomy and physiology at Bonn University (1855), of physiology at Heidelberg (1858), and of physics at Berlin (1871); in 1887 he became the founding director of the first institute of pure scientific research, the Physikalisch-Technische Reichsanstalt, Berlin. Helmholtz was an intellectual giant. His research covered such diverse topics as nerve impulses, colour blindness, vortex motion in the theory of fluids, and various aspects of electricity; he invented the ophthalmoscope; he created physiological optics and was a dominant figure in the area of acoustics....
James F. Bell
revised by Clive Greated
James F. Bell
revised by 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 (1833–49) as professor of physics and rector of the Polytechnic Institute at Nuremberg. Among his writings is the paper of 1827 which contained the famous Ohm’s Law of Electricity, which however was little recognized at the time. His contribution to music is contained in two papers (published in Annalen der Physik uns Chemie, 1843 and 1844) in which he presented what became known as Ohm’s Law of Acoustics: he suggested that musical sounds depended not on phase but on the distribution of energies among the harmonics. His research stimulated Helmholtz’s important experiments in the 1850s and 1860s, and dominated the conception of the subject for a century. Ohm’s place in musical acoustics, although less publicized, is as secure as his place in electromagnetic theory....
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 1820 and was elected to the Académie in 1827, also obtaining an appointment at the Collège de France. He is known mainly for the Biot–Savart Law of Electrodynamics. His chief interest, indicated by the titles of his 27 papers (mostly published in the Annales de chimie et de physique), was in the study of vibrating bodies. These included important and often ingenious measurements of air, cords, bars, membranes, plates, solids of revolution and, particularly, vocal cords. He proposed theories of the vocal sounds of men and animals. His repetition and extension of Chladni’s experiments with sand figures on vibrating plates and longitudinal bars led in the early 19th century to controversy over the velocity of sound in solids. In ...
(b 1892; d 1979). American engineer and acoustician. He had a distinguished professional career as an electrical engineer, specializing in research into radio wave transmission. In 1957 he retired from the directorship of radio research at Bell Telephone Laboratories. An enthusiastic amateur cellist, Schelleng undertook a programme of research into the acoustics of the violin family in his retirement. The combination of his musical experience and his background in electrical engineering resulted in a novel and extremely fruitful approach to the study of bowed string instruments, in which he drew an analogy between the exchange of vibrational energy between the string and the body of the instrument and the flow of electrical current round a circuit. His seminal paper, ‘The Violin as a Circuit’ (1963), provided the first realistic picture of how the violin functions as a whole, and became the foundation for most subsequent work in this area. Schelling was a pivotal figure in the group of researchers in violin acoustics which adopted the whimsical name Catgut Acoustical Society at his suggestion. He worked closely with Carleen Hutchins on the development of the Violin Octet, a set of new instruments based on the application of scaling theory to the violin. He was elected a fellow of the Acoustical Society of America in ...