Captain Henry Joseph Round (2 June 1881 – 17 August 1966) was an English engineer and one of the early pioneers of radio. He was the first to report the observation of

electroluminescence Electroluminescence (EL) is an optical phenomenon, optical and electrical phenomenon, in which a material emits light in response to the passage of an electric current or to a strong electric field. This is distinct from black body light emission ...

from a solid state diode, leading to the discovery of the

light-emitting diode A light-emitting diode (LED) is a semiconductor device that emits light when current flows through it. Electrons in the semiconductor recombine with electron holes, releasing energy in the form of photons. The color of the light (corre ...

. He was a personal assistant to

Guglielmo Marconi Guglielmo Giovanni Maria Marconi, 1st Marquess of Marconi ( ; ; 25 April 1874 – 20 July 1937) was an Italian electrical engineer, inventor, and politician known for his creation of a practical radio wave-based Wireless telegraphy, wireless tel ...

. Round was the eldest child of Joseph and Gertrude Round. He spent his early years in the small town of

Kingswinford Kingswinford is a town of the Metropolitan Borough of Dudley in the English West Midlands (county), West Midlands, situated west-southwest of central Dudley. In 2011 the area had a population of 25,191, down from 25,808 at the 2001 Census. T ...

Staffordshire Staffordshire (; postal abbreviation ''Staffs''.) is a Ceremonial counties of England, ceremonial county in the West Midlands (region), West Midlands of England. It borders Cheshire to the north-west, Derbyshire and Leicestershire to the east, ...

and received his early education at

Cheltenham Grammar School Pate's Grammar School is a grammar school with Academy (English school), academy status in Cheltenham, Gloucestershire, England. It caters for pupils aged 11 to 18. The school was founded with a fund bestowed to Corpus Christi College, Oxford, ...

. He later attended the Royal College of Science, a constituent college of

Imperial College London Imperial College London, also known as Imperial, is a Public university, public research university in London, England. Its history began with Prince Albert of Saxe-Coburg and Gotha, Prince Albert, husband of Queen Victoria, who envisioned a Al ...

, where he gained a first-class honours degree. Round joined the

Marconi Company The Marconi Company was a British telecommunications and engineering company founded by Italian inventor Guglielmo Marconi in 1897 which was a pioneer of wireless long distance communication and mass media broadcasting, eventually becoming on ...

in 1902, not long after Marconi had made his transatlantic wireless transmission. He was sent to the United States, where he experimented with a variety of different aspects of radio technology, focusing on technologies such as powdered iron cored tuning

inductor An inductor, also called a coil, choke, or reactor, is a Passivity (engineering), passive two-terminal electronic component, electrical component that stores energy in a magnetic field when an electric current flows through it. An inductor typic ...

s. He also performed some experiments with transmission paths over land and sea at different times of the day and investigated direction finding, for which he used a frame antenna.

Vacuum tube development

Round made important contributions to the development of the first vacuum tubes. He headed Marconi's research program into thermionic tubes and developed a three-element (

triode A triode is an electronic amplifier, amplifying vacuum tube (or ''thermionic valve'' in British English) consisting of three electrodes inside an evacuated glass envelope: a heated Electrical filament, filament or cathode, a control grid, grid ...

) amplifying tube at roughly the same time as

Lee De Forest #REDIRECT Lee de Forest {{redirect category shell, {{R from move{{R from other capitalisation ...

was developing the

Audion The Audion was an electronic detecting or amplifying vacuum tube invented by American electrical engineer Lee de Forest as a diode in 1906.De Forest patented a number of variations of his detector tubes starting in 1906. The patent that most cle ...

in the US. He discovered

feedback Feedback occurs when outputs of a system are routed back as inputs as part of a chain of cause and effect that forms a circuit or loop. The system can then be said to ''feed back'' into itself. The notion of cause-and-effect has to be handle ...

(regeneration) in vacuum tubes independently along with

Alexander Meissner Alexander Meissner (September 14, 1883 – January 3, 1958) was an Austrian engineer and physicist. He was born in Vienna and died in Berlin. His field of interest was: antenna design, amplification and detection advanced the development of rad ...

and

Edwin Armstrong Edwin Howard Armstrong (December 18, 1890 – February 1, 1954) was an American electrical engineer and inventor who developed FM (frequency modulation) radio and the superheterodyne receiver system. He held 42 patents and received numerous aw ...

, and built some of the first AM vacuum tube radio transmitters. He patented the first design for an indirectly heated cathode, the type of cathode widely used in vacuum tubes today.

Light-emitting diode

In some later experiments with

cat's whisker detector A crystal detector is an obsolete electronic component used in some early 20th century radio receivers. It consists of a piece of crystalline mineral that rectifies an alternating current radio signal. It was employed as a detector (demodula ...

s using a variety of substances, he passed current through them and noticed that some gave off light – the first known report of the effect of the light-emitting diode (LED). Round published his result in 1907 in ''Electrical World'':. Round's letter is dated 9 February 1907.

Military service

The

First World War World War I or the First World War (28 July 1914 – 11 November 1918), also known as the Great War, was a World war, global conflict between two coalitions: the Allies of World War I, Allies (or Entente) and the Central Powers. Fighting to ...

broke out in 1914, and in December 1914, Round was commissioned onto the General List and was seconded to the newly established Intelligence Corps with the rank of temporary lieutenant. Using his experience in direction finding, Round set up a series of direction-finding stations along the Western Front. These wireless direction-finding stations proved so successful that a chain of wireless direction-finding stations (named 'B' stations to differentiate them from interception stations which were designated 'Y' stations) were installed along the British coastline to monitor the movements of German airships, ships, and U-boats (submarines). In May 1916, the stations were monitoring transmissions from the German Navy at anchor at

Wilhelmshaven Wilhelmshaven (, ''Wilhelm's Harbour''; Northern Low Saxon: ''Willemshaven'') is a coastal town in Lower Saxony, Germany. It is situated on the western side of the Jade Bight, a bay of the North Sea, and has a population of 76,089. Wilhelmsha ...

. On 30 May the stations reported a 1.5-degree change in the direction of the signals - suggesting that the ships were on the move. Consequently, the

British Admiralty The Admiralty was a Departments of the Government of the United Kingdom, department of the Government of the United Kingdom that was responsible for the command of the Royal Navy. Historically, its titular head was the Lord High Admiral of the ...

ordered the British fleet to set sail and engage the German fleet. The

Battle of Jutland The Battle of Jutland () was a naval battle between Britain's Royal Navy Grand Fleet, under Admiral John Jellicoe, 1st Earl Jellicoe, Sir John Jellicoe, and the Imperial German Navy's High Seas Fleet, under Vice-Admiral Reinhard Scheer, durin ...

, the largest sea battle of all time, occurred the next day. On 6 September 1916, possibly in recognition of his contribution to the

and in wider recognition of his work, Round was appointed as a temporary Captain "while mployedof pecialduty." Round's promotion to temporary Captain at the Intelligence Corps was confirmed in the

1917 New Year Honours The 1917 New Year Honours were appointments by King George V to various orders and honours to reward and highlight good works by citizens of the British Empire. The appointments were published in several editions of ''The London Gazette'' in Ja ...

. On 31 May 1918 and in recognition of his service during the war, Round was awarded the

Military Cross The Military Cross (MC) is the third-level (second-level until 1993) military decoration awarded to officers and (since 1993) Other ranks (UK), other ranks of the British Armed Forces, and formerly awarded to officers of other Commonwealth of ...

. After the war, Round returned to civilian life and became involved in radio transmitters and was heavily involved in the first broadcasts made in the United Kingdom. Round became Chief Engineer at

Marconi's Wireless Telegraph Company The Marconi Company was a British telecommunications and engineering company founded by Italian inventor Guglielmo Marconi in 1897 which was a pioneer of wireless long distance communication and mass media broadcasting, eventually becoming on ...

in 1921, but some years later, he left to set up his own consultancy. When the

Second World War World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...

broke out in 1939, the British Government again called on his services. This time he was involved in

ASDIC Sonar (sound navigation and ranging or sonic navigation and ranging) is a technique that uses sound propagation (usually underwater, as in submarine navigation) to navigate, measure distances ( ranging), communicate with or detect objects o ...

(Anti-Submarine Detection Investigation Committee) which is known today as

sonar Sonar (sound navigation and ranging or sonic navigation and ranging) is a technique that uses sound propagation (usually underwater, as in submarine navigation) to navigate, measure distances ( ranging), communicate with or detect objects o ...

Later life

In 1961 - possibly in honour of his 80th birthday - Jeanne D. Round made a bronze bust of "Captain H.J. Round, M.C.", now owned by

BAE Systems BAE Systems plc is a British Multinational corporation, multinational Aerospace industry, aerospace, military technology, military and information security company, based in London. It is the largest manufacturer in Britain as of 2017. It is ...

and on loan to Sandford Mill, part of Chelmsford Museum. Round died in August 1966, aged 85, in a nursing home in

Bognor Regis Bognor Regis (), also known as Bognor, is a town and seaside resort in West Sussex on the south coast of England, south-west of London, west of Brighton, south-east of Chichester and east of Portsmouth. Other nearby towns include Littleham ...

after a short illness.

Vacuum tube development

Light-emitting diode

Military service

Later life

References

Further reading