John Ambrose Fleming

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Sir J. Ambrose Fleming
John Ambrose Fleming (1849-1945)
John Ambrose Fleming (1849-1945)
Born November 29, 1849
Lancaster, Lancashire, England
Died April 18, 1945
Sidmouth, Devon, England
Residence England
Nationality English
Field Electrical engineer and physicist
Institution University College, London
University of Nottingham
Cambridge University
Edison Electric Light Co.
Alma mater University College, London
Royal College of Science
Academic advisor Frederick Guthrie
Notable students Harold Barlow
Known for Fleming's left hand rule
Fleming's right hand rule
Kenotron
Notable prizes Hughes Medal (1910)
IRE Medal of Honor (1933)
Religion Congregationalist

Sir John Ambrose Fleming (sometimes also listed as Ambrose J. Fleming), (November 29, 1849 - April 18, 1945) was an English electrical engineer and physicist. He was born John Ambrose Fleming on November 29, 1849 to James and Mary Anne Fleming at Lancaster, Lancashire and baptised on February 11, 1850. He was a devout Christian and preached on one occasion at St Martin-in-the-Fields in London on the topic of evidence for the resurrection. In the 1930s he helped to start the Evolution Protest Movement. Having no children, he bequeathed much of his estate to Christian charities, especially those that helped the poor. He was an accomplished photographer and, in addition, he painted watercolours and enjoyed climbing in the Alps.

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[edit] Early years

Ambrose Fleming was born in Lancaster and educated at the University College School, London, and the University College London. He became a Lecturer at a number of universities including the University of Cambridge, the University of Nottingham, and University College London, where he was the first professor of Electrical Engineering. Consultant to the Marconi Wireless Telegraph Company, Swan, Ferranti, Edison Telephone, and later the Edison Electric Light Company. In 1892, Fleming presented an important paper on electrical transformer theory to the Institution of Electrical Engineers in London.

[edit] Education

Fleming started school at about the age of ten, attending a private school where he particularly enjoyed geometry. Prior to that his mother tutored him and he had learned, virtually by heart, a book called the Child's Guide to Knowledge, a popular book of the day - even as an adult he would quote from it. His schooling continued at the University College School where, although accomplished at maths, he habitually came bottom of the class at Latin.

Even as a boy he wanted to become an engineer. At 11 he had his own workshop where he built model boats and engines. He even built his own camera, the start of a lifelong interest in photography. Training to become an engineer was beyond the family's financial resources, but he reached his goal via a path that alternated education with work.

He enrolled for a BSc degree at University College, London, graduated in 1870, and studied under the mathematician Augustus de Morgan and the physicist G. Carey Foster. He became a student of chemistry at the Royal College of Science in South Kensington in London (now Imperial College). There he first studied the voltaic battery, which became the subject of his first scientific paper. This was the first paper to be read to the new Physical Society of London (now the Institute of Physics) and appears on page one of volume one of their Proceedings. Financial problems again forced him to work for his living and in the summer of 1874 he became science master at Cheltenham College, a public School, earning £400 per year. His own scientific research continued and he corresponded with James Clerk Maxwell at Cambridge University. After saving £400, and securing a grant of £50 a year, in October 1877 he once again enrolled as a student, this time at Cambridge. He was now 28 years old. Maxwell's lectures, he admitted, were difficult to follow. Maxwell, he said, often appeared obscure and had 'a paradoxical and allusive way of speaking'. On occasions Fleming was the only student at those lectures. Fleming again graduated, this time with a first in chemistry and physics. He then obtained a DSc from London and served one year at Cambridge University as a demonstrator of mechanical engineering before being appointed as the first Professor of Physics and Mathematics at the University of Nottingham. But after less than a year he left.

[edit] Notable achievements

In November 1904, he invented and patented the two-electrode vacuum-tube rectifier, which he called the oscillation valve. It was also called a thermionic valve, vacuum diode, kenotron, thermionic tube, or Fleming valve. This invention is often considered to have been the beginning of electronics, for this was the first vacuum tube. Fleming's diode was a vital unit in radio receivers and radars for many decades afterwards, until solid-state electronic technology took over.

In 1906, Lee De Forest of the USA added a control "grid" to the valve to create a vacuum tube RF detector called the Audion, leading Fleming to accuse him of copying his ideas. De Forest's device was shortly refined by him into an amplifier tube called the triode. The triode was vital in the creation of long-distance telephone and radio communications, radars, and early digital computers.

Fleming also contributed in the fields of photometry, electronics, wireless telegraphy (radio), and electrical measurements. He was knighted in 1929, and he died at Sidmouth in Devon in 1945. His contributions to electronic communications and radar were of vital importance in winning World War II.

Fleming was awarded the IRE Medal of Honor in 1933 for "the conspicuous part he played in introducing physical and engineering principles into the radio art."

[edit] Books by Fleming

  • The Thermionic Valve and its Development in Radio Telegraphy and Telephony, 1919.
  • The Principles of Electric Wave Telegraphy, 1906.

[edit] References

  • James E. Brittain, "John A. Fleming", Proceedings of the IEEE, Vol. 95, No. 1, 2007, pp. 313-315.

[edit] External articles

Patents
Websites
Persondata
NAME Fleming, Sir J. Ambrose
ALTERNATIVE NAMES
SHORT DESCRIPTION Electrical engineer and physicist
DATE OF BIRTH November 29, 1849
PLACE OF BIRTH Lancaster, Lancashire, England
DATE OF DEATH April 18, 1945
PLACE OF DEATH Sidmouth, Devon, England
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