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HJ Round Was A Pioneer In

The Development Of The LED



Captain Henry Joseph Round (2 June 1881, Kingswinford, Staffordshire, England–17 August 1966, Bognor Regis) was one of the early pioneers of radio and received 117 patents. He was a personal assistant to Guglielmo Marconi.

Henry Joseph Round was the eldest child of Joseph and Gertrude Round and was born on 2 June 1881. He spent his early years in the small town of Kingswinford which is in Staffordshire, England.


School And Work
Henry Round undertook much of his early education at Cheltenham Grammar School. He later attended the Royal College of Science where he gained first class honors degree.

Round joined the Marconi Company 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 dust cored tuning inductors. 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.

Where LED's Began
In some later experiments with cat's whisker detectors using a variety of substances, he passed current through them and noticed that some actually gave off light - the first time a light-emitting diode had been seen. Round reported this in the February 9, 1907 edition of Electrical World. This is the first known report of the effect of the light-emitting diode.

" To the Editors of Electrical World:

SIRS: During an investigation of the unsymmetrical passage of current through a contact of carborundum and other substances a curious phenomenon was noted. On applying a potential of 10 volts between two points on a crystal of carborundum, the crystal gave out a yellowish light.
Only one of two specimens could be found which gave a bright glow on such a low voltage, but with 110 volts a large number could be found to glow. In some crystals only edges gave the light and others gave instead of a yellow light green, orange or blue.
In all cases tested the glow appears to come from the negative pole, a bright blue-green spark appearing at the positive pole.
In a single crystal, if contact is made near the center with the negative pole, and the positive pole is put in contact at any other place, only one section of the crystal will glow and that same section wherever the positive pole is placed.

There seems to be some connection between the above effect and the e.m.f. produced by a junction of carborundum and another conductor when heated by a direct or alternating current; but the connection may be only secondary as an obvious explanation of the e.m.f. effect is the thermoelectric one.
The writer would be glad of references to any published account of an investigation of this or any allied phenomena.

New York, N. Y.

H. J. Round "

His Part In War
The First World War broke out in 1914 and Round was seconded to Military Intelligence with the rank of Captain. Using his experience in direction finding he set up a chain of direction finding stations along the Western Front. These stations proved so successful that another set was installed in England. Then in May 1916 they were monitoring transmissions from the German Navy at anchor at Wilhelmshaven. However on 30 May they reported a 1.5 degree change in the direction of the signals being perceived. When they heard of this the British Admiralty, the body controlling the Navy ordered the British fleet to set sail and engae them in Battle. The following day the Battle of Jutland was fought. It was the largest sea battle of all time.

For all his services during the war, Round was awarded the Military Cross. 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.

For all his successes, Round was made Chief Engineer at Marconi in 1921, but some years later he decided to set up his own consultancy.

With war breaking out again in 1939, the British Government again called on his services. This time he was involved in ASDIC (Anti-Submarine Detection Investigation Committee) which is known today as Sonar.

Round died in August 1966 in a nursing home in Bognor Regis after a short illness.


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