Stephen Butterworth
Encyclopedia
Stephen Butterworth was a British
physicist
who invented the Butterworth filter
, a class of electrical circuits that are used to separate different frequencies of electrical signals.
Stephen Butterworth was born on 11 August 1885 in Rochdale
, Lancashire
, England
(a town located about 10 miles north of the city of Manchester). He was the son of Alexander Butterworth, a postman, and Elizabeth (maiden name unknown). He was the second of four children. In 1904, he entered the University of Manchester, from which he received, in 1907, both a Bachelor of Science degree in physics (first class) and a teacher's certificate (first class). In 1908 he received a Master of Science degree in physics. For the next 11 years he was a physics lecturer at the Manchester Municipal College of Technology. He subsequently worked for several years at the National Physical Laboratory, where he did theoretical and experimental work for the determination of standards of electrical inductance. In 1921 he joined the Admiralty's Research Laboratory
. Unfortunately, the classified nature of his work prohibited the publication of much of his research there. Nevertheless, it is known that he worked in a wide range of fields; e.g., he determined the electromagnetic field around submarine cables carrying a.c. current, and he investigated underwater explosions and the stability of torpedoes. In 1939, he was a "Principal Scientific Officer" at the Admiralty Research Laboratory in the Admiralty's Scientific Research and Experiment Department. During World War II, he investigated both magnetic mines
and the degaussing
of ships (as a means of protecting them from magnetic mines).
He was a first-rate applied mathematician. He often solved problems that others had regarded as insoluble. For his successes, he employed judicious approximations, penetrating physical insight, ingenious experiments, and skillful use of models. He was a quiet and unassuming man. Nevertheless, his knowledge and advice were widely sought and readily offered. He was respected by his colleagues and revered by his subordinates.
In 1942 he was awarded the Order of the British Empire. In 1945 he retired from the Admiralty Research Laboratory. He died on 28 October 1958 at his home in Cowes on the Isle of Wight, England.
British people
The British are citizens of the United Kingdom, of the Isle of Man, any of the Channel Islands, or of any of the British overseas territories, and their descendants...
physicist
Physicist
A physicist is a scientist who studies or practices physics. Physicists study a wide range of physical phenomena in many branches of physics spanning all length scales: from sub-atomic particles of which all ordinary matter is made to the behavior of the material Universe as a whole...
who invented the Butterworth filter
Butterworth filter
The Butterworth filter is a type of signal processing filter designed to have as flat a frequency response as possible in the passband so that it is also termed a maximally flat magnitude filter...
, a class of electrical circuits that are used to separate different frequencies of electrical signals.
Stephen Butterworth was born on 11 August 1885 in Rochdale
Rochdale
Rochdale is a large market town in Greater Manchester, England. It lies amongst the foothills of the Pennines on the River Roch, north-northwest of Oldham, and north-northeast of the city of Manchester. Rochdale is surrounded by several smaller settlements which together form the Metropolitan...
, Lancashire
Lancashire
Lancashire is a non-metropolitan county of historic origin in the North West of England. It takes its name from the city of Lancaster, and is sometimes known as the County of Lancaster. Although Lancaster is still considered to be the county town, Lancashire County Council is based in Preston...
, England
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...
(a town located about 10 miles north of the city of Manchester). He was the son of Alexander Butterworth, a postman, and Elizabeth (maiden name unknown). He was the second of four children. In 1904, he entered the University of Manchester, from which he received, in 1907, both a Bachelor of Science degree in physics (first class) and a teacher's certificate (first class). In 1908 he received a Master of Science degree in physics. For the next 11 years he was a physics lecturer at the Manchester Municipal College of Technology. He subsequently worked for several years at the National Physical Laboratory, where he did theoretical and experimental work for the determination of standards of electrical inductance. In 1921 he joined the Admiralty's Research Laboratory
Admiralty Research Laboratory
The Admiralty Research Laboratory, or ARL, was a research laboratory that supported the work of the UK Admiralty in Teddington, London, England....
. Unfortunately, the classified nature of his work prohibited the publication of much of his research there. Nevertheless, it is known that he worked in a wide range of fields; e.g., he determined the electromagnetic field around submarine cables carrying a.c. current, and he investigated underwater explosions and the stability of torpedoes. In 1939, he was a "Principal Scientific Officer" at the Admiralty Research Laboratory in the Admiralty's Scientific Research and Experiment Department. During World War II, he investigated both magnetic mines
Naval mine
A naval mine is a self-contained explosive device placed in water to destroy surface ships or submarines. Unlike depth charges, mines are deposited and left to wait until they are triggered by the approach of, or contact with, an enemy vessel...
and the degaussing
Degaussing
Degaussing is the process of decreasing or eliminating an unwanted magnetic field. It is named after Carl Friedrich Gauss, an early researcher in the field of magnetism...
of ships (as a means of protecting them from magnetic mines).
He was a first-rate applied mathematician. He often solved problems that others had regarded as insoluble. For his successes, he employed judicious approximations, penetrating physical insight, ingenious experiments, and skillful use of models. He was a quiet and unassuming man. Nevertheless, his knowledge and advice were widely sought and readily offered. He was respected by his colleagues and revered by his subordinates.
In 1942 he was awarded the Order of the British Empire. In 1945 he retired from the Admiralty Research Laboratory. He died on 28 October 1958 at his home in Cowes on the Isle of Wight, England.
Publications
- S. Butterworth (December 1911) “On the vibration galvanometer and its application to inductance bridges,” Proceedings of the Physical Society of London, vol. 24, pages 75–94.
- S. Butterworth (December 1911) “A method of measuring small inductances,” Proceedings of the Physical Society of London, vol. 24, pages 210-214.
- S. Butterworth (December 1912) “On the evaluation of certain combinations of the Ber, Bei and allied functions,” Proceedings of the Physical Society of London, vol. 25, pages 294-297.
- S. Butterworth (December 1913) “On a null method of testing vibration galvanometers,” Proceedings of the Physical Society of London, vol. 26, pages 264-273.
- S. Butterworth (December 1914) “On the self-induction of solenoids of appreciable winding depths,” Proceedings of the Physical Society of London, vol. 27, pages 371-383.
- S. Butterworth (December 1914) “On electrically-maintained vibrations,” Proceedings of the Physical Society of London, vol. 27, pages 410-424.
- S. Butterworth (December 1919) “On the self-inductance of single-layer flat coils,” Proceedings of the Physical Society of London, vol. 32, pages 31–37.
- S. Butterworth (December 1919) “The maintenance of a vibrating system by means of a triode valve,” Proceedings of the Physical Society of London, vol. 32, pages 345-360.
- S. Butterworth (December 1920) “Capacity and eddy current effects in inductometers,” Proceedings of the Physical Society of London, vol. 33, pages 312-354.
- S. Butterworth (December 1921) “On the use of Anderson's bridge for the measurement of the variations of the capacity and effective resistance of a condenser with frequency” Proceedings of the Physical Society of London, vol. 34, pages 1–7.
- S. Butterworth (December 1921) “Notes on Earth Capacity Effects in Alternating-Current Bridges,” Proceedings of the Physical Society of London, vol. 34, pages 8–16.
- S. Butterworth (1922) “III. Eddy-current losses in cylindrical conductors, with special applications to the alternating current resistances of short coils,” Philosophical Transactions of the Royal Society of London, Series A, vol. 222, pages 57–100.
- S. Butterworth (1924) "Note on the alternating current resistance of single layer coils," Physical Review, vol. 23, pages 752-755.
- S. Butterworth (1924) “The distribution of the magnetic field and return current round a submarine cable carrying alternating current. Part 2,” Philosophical Transactions of the Royal Society of London. Series A, vol. 224, pages 141-184.
- S. Butterworth (1 April 1925) “On the alternating current resistance of solenoidal coils,” Proceedings of the Royal Society of London. Series A, vol. 107, no. 744, pages 693-715.
- S. Butterworth, A. B. Wood, and E. H. Lakey (October 1926) “The use of a resonant shunt with an Einthoven string galvanometer,” Journal of Scientific Instruments, vol. 4, no. 1, pages 8–18.
- S. Butterworth (1926) "Effective resistance of inductance coils at radio frequencies," Experimental Wireless and the Wireless Engineer, vol. 3, pages 203, 267, 417 and 483.
- S. Butterworth (1926) "Designing low-loss receiving coils," Wireless World, vol. 19, pages 754 and 811.
- S. Butterworth (January 1929) "The high frequency resistance of toroidal coils," Experimental Wireless and the Wireless Engineer, vol. 6, pages 13–16.
- S. Butterworth (November 1929) "Note on the apparent demodulation of a weak station by a stronger one," Experimental Wireless and the Wireless Engineer, vol. 6, no. 74, page 619.
- S. Butterworth (1930) "On the theory of filter amplifiers," Experimental Wireless and the Wireless Engineer, vol. 7, pp. 536–541.
- S. Butterworth and F.D. Smith (1 March 1931) “The equivalent circuit of the magnetostriction oscillator,” Proceedings of the Physical Society of London, vol. 43, no. 2, pages 166-185.