John Tasker Henderson
Encyclopedia
John Tasker Henderson was a Canadian Physicist whose career was with the National Research Council (NRC). He is particularly recognized for his leadership role in radar technology during World War II
.
Henderson was born in Montréal
, Canada. He received the B.S. and M.S. degrees in engineering physics from McGill University
, and then went to England, where he studied under Professor E. V. Appleton. He received the Ph.D. degree in physics from the University of London
in 1932, and followed this with post-doctoral studies at the Sorbonne
in Paris
and the Technische Hochschule
at Munich
. In 1933, he joined the NRC in Ottawa
as chief of the Radio Section. Over the next several years, his work included the building of a highly advanced radio direction-finding
set that used a CRT for its display; this was installed in Nova Scotia
in 1938.
In early 1939, Henderson was selected to represent Canada in a series of highly classified briefings in Great Britain concerning developments in the Air Ministry
on Range and Direction Finding
(RDF – later called radar). This was largely coordinated by Robert Watson-Watt
at RAF Bawdsey
, with the purpose of preparing the Commonwealth of Nations
to have indigenous developments in this technology.
Upon Henderson’s return from the briefings in England, arrangements were made between the Canadian and American governments for him to visit a number of facilities in the U.S. Following this. he prepared a detailed report that included proposed plans for bringing the NRC into the RDF activities. Within a short time, he was authorized to set up a development laboratory for this in the NRC Radio Section. Its first project was the development of s surface-warning radar system for the Royal Canadian Navy
. Using commercial components and with essentially no further assistance from Great Britain, a system was developed to protect the entrance to the Halifax Harbour
; called Night Watchman, it was tested in June 1940. This was followed by a ship-borne system designated Surface Warning 1st Canadian (SW1C) completed in May 1941.
In the summer of 1940, Great Britain was at the limit of production capability and desperately needed allies for her war effort. Arranged were made for an exchange of classified information with the United States. For this, Sir. Henry Tizard
assembled a delegation for what came to be known as the Tizard Mission
. On the way to Washington, D.C.
, Tizard and others went by Ottawa and briefed NRC officials and also visited the Radio Section. Highly impressed, Tizard asked that Henderson join the delegation to represent Canada at the exchanges. The new cavity magnetron
developed in Great Britain was a key item; at the Washington meeting, Henderson was asked to take the lead in both manufacturing this unit in Canada as well as developing microwave radars using the magnetron.
By the end of 1940, Henderson's organization was elevated to Branch level and many engineers and scientists were added. For testing the systems, a secure Radio Field Station was set up near Ottawa. To manufacture the hardware, a Crown company, Research Enterprises, Ltd. (REL), was established, with a large facility near Toronto
. The NRC's Radio Branch remained at the center of radar development in Canada throughout World War II. Many radar systens were designed at this facility during the war years – a total of 30 of all types.
After laying the foundation for research and manufacturing of radar in Canada, in 1942 Henderson became a senior officer in the Royal Canadian Air Force
(RCAF). For the next three years, he was in RCAF Radar and Signals units with assignments in Canada, Newfoundland, England, and Germany. After the war, he was a scientific advisor to the Canadian delegation of the United Nation's Commission on Atomic Energy.
Near the end of 1947, Henderson returned to the NRC to head the Canadian part of SHORAN
, an interdepartmental project to apply radar techniques to aerial surveying. In 1949, he was placed in charge of the Electricity Section in the Applied Physics Division; here, he set up new absolute electrical standards for Canada in conformity with international agreements. Among other activities, he led the development of several caesium
-133 atomic clock
s that were accepted in 1967 as the international timekeeping standard. He eventually became the Principle Research Officer of the NRC, a position he held until his retirement in 1970.
In 1943, Henderson was awarded the Member of the Order of the British Empire
, Dominion of Canada, for his pioneer work in the radar field. He was made a Fellow of the Royal Society of Canada
, a Fellow of the Institute of Radio Engineers
(IRE), and in 1963 was elected as President of the newly merged Institute of Electrical and Electronics Engineers
(IEEE). In 1969, he was the first recipient of the McNaughton Medal, an annual award given by the IEEE Canada in recognition of contributions to the engineering profession. John T. Henderson died in Perth, Ontario
, on 2 January 1983
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
.
Henderson was born in Montréal
Montreal
Montreal is a city in Canada. It is the largest city in the province of Quebec, the second-largest city in Canada and the seventh largest in North America...
, Canada. He received the B.S. and M.S. degrees in engineering physics from McGill University
McGill University
Mohammed Fathy is a public research university located in Montreal, Quebec, Canada. The university bears the name of James McGill, a prominent Montreal merchant from Glasgow, Scotland, whose bequest formed the beginning of the university...
, and then went to England, where he studied under Professor E. V. Appleton. He received the Ph.D. degree in physics from the University of London
University of London
-20th century:Shortly after 6 Burlington Gardens was vacated, the University went through a period of rapid expansion. Bedford College, Royal Holloway and the London School of Economics all joined in 1900, Regent's Park College, which had affiliated in 1841 became an official divinity school of the...
in 1932, and followed this with post-doctoral studies at the Sorbonne
Sorbonne
The Sorbonne is an edifice of the Latin Quarter, in Paris, France, which has been the historical house of the former University of Paris...
in Paris
Paris
Paris is the capital and largest city in France, situated on the river Seine, in northern France, at the heart of the Île-de-France region...
and the Technische Hochschule
Technische Hochschule
Technische Hochschule is what an Institute of Technology used to be called in German-speaking countries, as well as in the Netherlands, before most of them changed their name to Technische Universität or Technische Universiteit in the 1970s and in the...
at Munich
Munich
Munich The city's motto is "" . Before 2006, it was "Weltstadt mit Herz" . Its native name, , is derived from the Old High German Munichen, meaning "by the monks' place". The city's name derives from the monks of the Benedictine order who founded the city; hence the monk depicted on the city's coat...
. In 1933, he joined the NRC in Ottawa
Ottawa
Ottawa is the capital of Canada, the second largest city in the Province of Ontario, and the fourth largest city in the country. The city is located on the south bank of the Ottawa River in the eastern portion of Southern Ontario...
as chief of the Radio Section. Over the next several years, his work included the building of a highly advanced radio direction-finding
Direction finding
Direction finding refers to the establishment of the direction from which a received signal was transmitted. This can refer to radio or other forms of wireless communication...
set that used a CRT for its display; this was installed in Nova Scotia
Nova Scotia
Nova Scotia is one of Canada's three Maritime provinces and is the most populous province in Atlantic Canada. The name of the province is Latin for "New Scotland," but "Nova Scotia" is the recognized, English-language name of the province. The provincial capital is Halifax. Nova Scotia is the...
in 1938.
In early 1939, Henderson was selected to represent Canada in a series of highly classified briefings in Great Britain concerning developments in the Air Ministry
Air Ministry
The Air Ministry was a department of the British Government with the responsibility of managing the affairs of the Royal Air Force, that existed from 1918 to 1964...
on Range and Direction Finding
Range and Direction Finding
Range and Direction Finding was the initial technique and hardware in Great Britain that eventually came to be called 'radar.'Since the earliest days of radio , the signals had been used in direction finding on land, sea, and in the air...
(RDF – later called radar). This was largely coordinated by Robert Watson-Watt
Robert Watson-Watt
Sir Robert Alexander Watson-Watt, KCB, FRS, FRAeS is considered by many to be the "inventor of radar". Development of radar, initially nameless, was first started elsewhere but greatly expanded on 1 September 1936 when Watson-Watt became...
at RAF Bawdsey
RAF Bawdsey
RAF Bawdsey was an RAF station situated on the eastern coast in Suffolk, England.Bawdsey Manor, dating from 1886, was taken over in March 1936 by the Air Ministry for developing the Chain Home RDF system...
, with the purpose of preparing the Commonwealth of Nations
Commonwealth of Nations
The Commonwealth of Nations, normally referred to as the Commonwealth and formerly known as the British Commonwealth, is an intergovernmental organisation of fifty-four independent member states...
to have indigenous developments in this technology.
Upon Henderson’s return from the briefings in England, arrangements were made between the Canadian and American governments for him to visit a number of facilities in the U.S. Following this. he prepared a detailed report that included proposed plans for bringing the NRC into the RDF activities. Within a short time, he was authorized to set up a development laboratory for this in the NRC Radio Section. Its first project was the development of s surface-warning radar system for the Royal Canadian Navy
Royal Canadian Navy
The history of the Royal Canadian Navy goes back to 1910, when the naval force was created as the Naval Service of Canada and renamed a year later by King George V. The Royal Canadian Navy is one of the three environmental commands of the Canadian Forces...
. Using commercial components and with essentially no further assistance from Great Britain, a system was developed to protect the entrance to the Halifax Harbour
Halifax Harbour
Halifax Harbour is a large natural harbour on the Atlantic coast of Nova Scotia, Canada, located in the Halifax Regional Municipality.-Harbour description:The harbour is called Jipugtug by the Mi'kmaq first nation, anglisized as Chebucto...
; called Night Watchman, it was tested in June 1940. This was followed by a ship-borne system designated Surface Warning 1st Canadian (SW1C) completed in May 1941.
In the summer of 1940, Great Britain was at the limit of production capability and desperately needed allies for her war effort. Arranged were made for an exchange of classified information with the United States. For this, Sir. Henry Tizard
Henry Tizard
Sir Henry Thomas Tizard FRS was an English chemist and inventor and past Rector of Imperial College....
assembled a delegation for what came to be known as the Tizard Mission
Tizard Mission
The Tizard Mission officially the British Technical and Scientific Mission was a British delegation that visited the United States during the Second World War in order to obtain the industrial resources to exploit the military potential of the research and development work completed by the UK up...
. On the way to Washington, D.C.
Washington, D.C.
Washington, D.C., formally the District of Columbia and commonly referred to as Washington, "the District", or simply D.C., is the capital of the United States. On July 16, 1790, the United States Congress approved the creation of a permanent national capital as permitted by the U.S. Constitution....
, Tizard and others went by Ottawa and briefed NRC officials and also visited the Radio Section. Highly impressed, Tizard asked that Henderson join the delegation to represent Canada at the exchanges. The new cavity magnetron
Cavity magnetron
The cavity magnetron is a high-powered vacuum tube that generates microwaves using the interaction of a stream of electrons with a magnetic field. The 'resonant' cavity magnetron variant of the earlier magnetron tube was invented by John Randall and Harry Boot in 1940 at the University of...
developed in Great Britain was a key item; at the Washington meeting, Henderson was asked to take the lead in both manufacturing this unit in Canada as well as developing microwave radars using the magnetron.
By the end of 1940, Henderson's organization was elevated to Branch level and many engineers and scientists were added. For testing the systems, a secure Radio Field Station was set up near Ottawa. To manufacture the hardware, a Crown company, Research Enterprises, Ltd. (REL), was established, with a large facility near Toronto
Toronto
Toronto is the provincial capital of Ontario and the largest city in Canada. It is located in Southern Ontario on the northwestern shore of Lake Ontario. A relatively modern city, Toronto's history dates back to the late-18th century, when its land was first purchased by the British monarchy from...
. The NRC's Radio Branch remained at the center of radar development in Canada throughout World War II. Many radar systens were designed at this facility during the war years – a total of 30 of all types.
After laying the foundation for research and manufacturing of radar in Canada, in 1942 Henderson became a senior officer in the Royal Canadian Air Force
Royal Canadian Air Force
The history of the Royal Canadian Air Force begins in 1920, when the air force was created as the Canadian Air Force . In 1924 the CAF was renamed the Royal Canadian Air Force and granted royal sanction by King George V. The RCAF existed as an independent service until 1968...
(RCAF). For the next three years, he was in RCAF Radar and Signals units with assignments in Canada, Newfoundland, England, and Germany. After the war, he was a scientific advisor to the Canadian delegation of the United Nation's Commission on Atomic Energy.
Near the end of 1947, Henderson returned to the NRC to head the Canadian part of SHORAN
SHORAN
SHORAN is an acronym for SHOrt RAnge Navigation, a type of electronic navigation and bombing system with a precision radar beacon used in the B-26 and B-29 bomber aircraft during the Korean War.-Origin:...
, an interdepartmental project to apply radar techniques to aerial surveying. In 1949, he was placed in charge of the Electricity Section in the Applied Physics Division; here, he set up new absolute electrical standards for Canada in conformity with international agreements. Among other activities, he led the development of several caesium
Caesium
Caesium or cesium is the chemical element with the symbol Cs and atomic number 55. It is a soft, silvery-gold alkali metal with a melting point of 28 °C , which makes it one of only five elemental metals that are liquid at room temperature...
-133 atomic clock
Atomic clock
An atomic clock is a clock that uses an electronic transition frequency in the microwave, optical, or ultraviolet region of the electromagnetic spectrum of atoms as a frequency standard for its timekeeping element...
s that were accepted in 1967 as the international timekeeping standard. He eventually became the Principle Research Officer of the NRC, a position he held until his retirement in 1970.
In 1943, Henderson was awarded the Member of the Order of the British Empire
Order of the British Empire
The Most Excellent Order of the British Empire is an order of chivalry established on 4 June 1917 by George V of the United Kingdom. The Order comprises five classes in civil and military divisions...
, Dominion of Canada, for his pioneer work in the radar field. He was made a Fellow of the Royal Society of Canada
Royal Society of Canada
The Royal Society of Canada , may also operate under the more descriptive name RSC: The Academies of Arts, Humanities and Sciences of Canada , is the oldest association of scientists and scholars in Canada...
, a Fellow of the Institute of Radio Engineers
Institute of Radio Engineers
The Institute of Radio Engineers was a professional organization which existed from 1912 until January 1, 1963, when it merged with the American Institute of Electrical Engineers to form the Institute of Electrical and Electronics Engineers .-Founding:Following several attempts to form a...
(IRE), and in 1963 was elected as President of the newly merged Institute of Electrical and Electronics Engineers
Institute of Electrical and Electronics Engineers
The Institute of Electrical and Electronics Engineers is a non-profit professional association headquartered in New York City that is dedicated to advancing technological innovation and excellence...
(IEEE). In 1969, he was the first recipient of the McNaughton Medal, an annual award given by the IEEE Canada in recognition of contributions to the engineering profession. John T. Henderson died in Perth, Ontario
Perth, Ontario
Perth is a town in the eastern portion of Southern Ontario, Canada . It is located on the Tay River, 83 km southwest of Ottawa, and is the seat of Lanark County.-History:...
, on 2 January 1983
General references
- Avery, Donald H.; The Science of War: Canadian Scientists and Allied Military Technology, Univ. Toronto Press, 1999; ISBN 0-8022-5996-1
- Middleton, W. E. Knowles; Radar Development in Canada: The Radio Branch of the National Research Council of Canada 1939-1946, Wilfrid Laurier Univ. Press, 1981; ISBN 0-88920-106-4
- Watson, Raymond C., Jr.; Radar Origins Worldwide: History of Its Evolution in 13 Nations Through World War II, Traford Publishing, 2009; ISBN 978-1-4269-2111-7