James Alfred Ewing
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| James Alfred Ewing | |
 James Alfred Ewing
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| Born | 27 March 1855 |
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| Died | 7 January 1935 |
| Nationality | Scottish |
| Fields | physicist and engineer |
| Known for | hysteresis |
Sir James Alfred Ewing KCB (27 March 1855 - 7 January 1935) was a Scottish physicist and engineer, best known for his work on the magnetic properties of metals and, in particular, for his discovery of, and coinage of the word, hysteresis.
(Note: According to the book Sir Alfred Ewing: A Pioneer in Physics and Engineering (1946) by Professor Bates, the discovery of magnetic hysteresis probably occurred before Ewing. However, Ewing re-discovered it, studied it in detail and coined the word hysteresis. Please see reference below.)
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[edit] Life
[edit] Early life
Born in Dundee, Scotland, the third son of a minister of the Free Church of Scotland and educated at West End Academy and the High School of Dundee, Ewing showed an early interest in science and technology.
In a family whose chief interests were clerical and literary, I took my pleasure in machines and experiments. My scanty pocket money was spent on tools and chemicals. The domestic attic was put at my disposal. It became the scene of hair-raising explosions. There too the domestic cat found herself an unwilling instrument of electrification and a partner in various shocking experiences.
Ewing graduated in engineering from the University of Edinburgh where he studied under William Thomson, 1st Baron Kelvin and Peter Guthrie Tait. During his summer vacations, he worked on telegraph cable laying expeditions, including one to Brazil, under Thomson and Fleeming Jenkin.
[edit] Japan
In 1878, on Fleeming Jenkin's recommendation, Ewing was recruited to help the modernisation of Meiji Era Japan as one of the o-yatoi gaikokujin (hired foreigners). Serving as professor of mechanical engineering at the University of Tokyo, he was instrumental in founding Japanese seismology.
Ewing made two special friends at Tokyo University soon after arriving: Basil Hall Chamberlain and Lieutenant Thomas Henry James R.N. who taught navigation. He was also in close contact with Henry Dyer and William Edward Ayrton at the Imperial College of Engineering (Kobu Dai Gakko).
In Tokyo, Ewing taught courses in mechanics and on heat engines to engineering students, and electricity and magnetism to students of physics. He carried out many research projects on magnetism and coined the word 'hysteresis'. His investigations into earthquakes led him to help T. Lomar Gray and John Milne of the Imperial College of Engineering to develop a seismometer. All three men worked as a team on the invention and use of seismographs, though Milne is generally credited with the invention of the first modern horizontal-pendulum seismograph.
[edit] Scotland
In 1883, Ewing returned to Scotland to work at the University College Dundee where he was appalled by the living conditions of many of the poorer areas of the town which he felt compared unfavourably with those in Japan. He worked fervently with local government and industry to improve amenities, in particular sewer systems, and to lower the infant mortality rate.
[edit] University of Cambridge
In 1890, he took up the post of professor of mechanism and applied mechanics at King's College, Cambridge. At Cambridge, Ewing's research into the magnetisation of metals led him to criticise the conventional account of Wilhelm Weber. In 1890, he observed that magnetisation lagged behind an applied alternating current. He described the characteristic hysteresis curve and speculated that individual molecules act as magnets, resisting changes in magnetising potential. Ewing was a close friend of Sir Charles Algernon Parsons and collaborated with him on the development of the steam turbine, participating in the sea-trials of the Turbinia. He also researched into the crystalline structure of metals and, in 1903, was the first to propose that fatigue failures originated in microscopic defects or slip bands in materials.
[edit] University of Edinburgh
In 1903, he became director of naval education at the Admiralty before becoming principal and vice-chancellor of the University of Edinburgh in 1916, a post he held until his retirement in 1929. From 1914 to May 1917, he managed Room 40, the admiralty intelligence department of cryptanalysis, responsible predominantly for the decryption of intercepted German naval messages. In this capacity, he achieved some notoriety in the popular press when Room 40 deciphered the Zimmermann Telegram in 1917 (which suggested a German plot to assist Mexico in annexing the southwestern United States).
In May 1916 Ewing accepted an invitation to become Vice-Chancellor of Edinburgh University, in the course of which he instituted an extensive series of effective reforms.
Knighted in 1911, Sir James Alfred Ewing retired from Edinburgh University in 1929 and died in 1935.
[edit] Honours
- Fellow of the Royal Society of Edinburgh (1878);
- Fellow of the Royal Society (1887);
- CB (1907);
- KCB (1911);
- President of the Royal Society of Edinburgh (1924 - 1929);
- Albert Medal of the Royal Society of Arts (1929);
- President of the British Association for the Advancement of Science (1932);
- The James Alfred Ewing Medal of the Institution of Civil Engineers has been awarded for specially meritorious contributions to the science of engineering in the field of research since 1938.
[edit] Works
- Ewing, J.A. (1883). Treatise on Earthquake Measurement.
- - (1891). Magnetic Induction in Iron and Other Metals. London: Van Nostrand.
- - (1894). The Steam Engine and other Heat Engines.
- - (1899). The Strength of Materials.
- - (1908). The Mechanical Production of Gold.
- - (1920). Thermodynamics for Engineers.
- - (1921). The Mechanical Production of Cold. Cambridge: Cambridge University Press.
- - (1933). An Engineer's Outlook. London: Methuen.
[edit] See also
[edit] Bibliography
- Bates, L. F. (1946) Sir Alfred Ewing: A Pioneer in Physics and Engineering ISBN 1-114-51704-6
- Pedlar, Neil, 'James Alfred Ewing and his circle of pioneering physicists in Meiji Japan', Hoare, J.E. ed., Britain & Japan: Biographical Portraits Volume III Chapter 8. Japan Library (1999). ISBN 1-873410-89-1
| Preceded by Sir William Turner |
Edinburgh University Principals 1916–1926 |
Succeeded by Thomas Henry Holland |
