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 observation of electroluminescence 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 (co ...

. He was a personal assistant to Guglielmo Marconi. 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, situated west-southwest of central Dudley. In 2011 the area had a population of 25,191, down from 25,808 at the 2001 Census. The current economic focus ...

in Staffordshire and received his early education at Cheltenham Grammar School. He later attended the

Royal College of Science The Royal College of Science was a higher education institution located in South Kensington; it was a constituent college of Imperial College London from 1907 until it was wholly absorbed by Imperial in 2002. Still to this day, graduates from th ...

, a constituent college of

Imperial College London Imperial College London (legally Imperial College of Science, Technology and Medicine) is a public research university in London, United Kingdom. Its history began with Prince Albert, consort of Queen Victoria, who developed his vision for a cu ...

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

Marconi Company The Marconi Company was a British telecommunications and engineering company that did business under that name from 1963 to 1987. Its roots were in the Wireless Telegraph & Signal Company founded by Italian inventor Guglielmo Marconi in 189 ...

in 1902; not long after Marconi had made his transatlantic wireless transmission. He was sent to the USA 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 passive two-terminal electrical component that stores energy in a magnetic field when electric current flows through it. An inductor typically consists of an insulated wire wound into a c ...

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 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 amplifying vacuum tube (or ''valve'' in British English) consisting of three electrodes inside an evacuated glass envelope: a heated filament or cathode, a grid, and a plate (anode). Developed from Lee De Forest's ...

) amplifying tube at roughly the same time as Lee De Forest was developing the

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

in the US. He discovered feedback (regeneration) in vacuum tubes independently along with

Alexander Meissner Alexander Meissner (in German: 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 ...

and Edwin Armstrong, 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 that consists of a piece of crystalline mineral which rectifies the alternating current radio signal. It was employed as a detector (dem ...

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 (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fightin ...

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. Wilhelmsh ...

. 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 ordered the British fleet to set sail and engage the German fleet. The Battle of Jutland, the largest sea battle of all time, occurred the next day. On 6 September 1916, possibly in recognition of his contribution to the Battle of Jutland 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 wartime service during the war, Round was awarded the

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

. 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 that did business under that name from 1963 to 1987. Its roots were in the Wireless Telegraph & Signal Company founded by Italian inventor Guglielmo Marconi in 1897 ...

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, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposi ...

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 on ...

(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 on 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 and on loan to Sandford Mill, part of

Chelmsford Museum The Chelmsford Museum is based in Oaklands House, an historic property off Moulsham Street in Chelmsford, Essex. It is a Grade II Listed building. Oaklands House The house was designed by Charles Pertwee for Frederick Wells, a director of the ...

. Round died in August 1966, aged 85, in a nursing home in

Bognor Regis Bognor Regis (), sometimes simply 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 i ...

after a short illness.

Vacuum tube development

Light-emitting diode

Military service

Later life

References

Further reading