David Edward Hughes

Lore & Background

Hughes was born in 1830, the son of a musically talented family hailing originally from Y Bala, and emigrated to the United States at the age of seven. At only six years old, he is known to have played the harp and English concertina to a very high standard. At an early age, Hughes developed such musical ability that he is reported to have attracted the attention of Herr Hast, an eminent German pianist in America, who procured for him a professorship of music at St. Joseph's College in Bardstown, Kentucky. Hughes also worked as a practical experimenter, coming up with the printing telegraph in 1855. He moved back to London in 1857 to sell his invention, and worked on the transmission of sound over wires. He worked on microphones and the development of the induction balance (later used in metal detectors). Despite Hughes' facility as an experimenter, he had little mathematical training. He was a friend of William Henry Preece.

In 1878 Hughes published his work on the effects of sound on the powered electronic sound pickups, called 'transmitters', being developed for telephones. He showed that the change in resistance in carbon telephone transmitters was a result of the interaction between carbon parts instead of the commonly held theory that it was from the compression of the carbon itself. Based on its ability to pick up extremely weak sounds, Hughes referred to it as a 'microphone effect'. He conducted a simple demonstration of this principle of loose contact by laying an iron nail across two other nails connected to a battery and galvanometer. His paper was read before the Royal Society of London by Thomas Henry Huxley on May 8, 1878, and his new 'microphone' was covered in the July 1 edition of Telegraph Journal and Electrical Review. Hughes would refine his microphone design using a series of 'carbon pencils' stuck into blocks of carbon to better pick up sound but never patented his work, thinking it should be publicly available for development by others.

Reader's Guide

Hughes' significance lies in his contributions to telegraphy, telephony, and the early detection of radio waves. His printing telegraph system became an international standard in Europe, and in the United States a number of small telegraph companies united to form the Western Union Telegraph Company to carry on the business of telegraphy on the Hughes system. His work on the carbon microphone clarified the principle of loose contact resistance, which was fundamental to telephone transmitters. Hughes seems to have come across the phenomenon of radio waves nine years before they were proven to exist by Heinrich Hertz in 1888. In 1879 while working in London he discovered that a bad contact in a Bell telephone seemed to be sparking when he worked on a nearby induction balance. He developed an improved detector based on his microphone design and found he could pick up these 'aerial waves' out to a range of 500 yards. On February 20, 1880, he demonstrated his technology to representatives of the Royal Society including Thomas Henry Huxley, Sir George Gabriel Stokes, and William Spottiswoode. Stokes was convinced the phenomenon was merely electromagnetic induction, and Hughes accepted this and did not pursue the experiments further. Hughes did not publish his findings but mentioned them in an 1899 letter to The Electrician magazine, where he commented that Hertz's experiments were 'far more conclusive than mine'. Elihu Thomson put forward a claim that Hughes was really the first to transmit radio. After Hughes' death the Hughes Medal was created by the Royal Society in his honour, to be awarded to other scientists for original discoveries in the physical sciences, particularly electricity and magnetism or their applications.

Did You Know?

• He never patented his carbon microphone, thinking it should be publicly available for development by others.
• In 1879 he detected what were probably radio waves nine years before Heinrich Hertz proved their existence.
• The Hughes Medal was created by the Royal Society after his death and first awarded in 1902.