Alexander Graham Bell

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Alexander Graham Bell. (Source: IEEE History Center)

Bell, Alexander Graham

November 17, 2008, 7:52 pm

Alexander Graham Bell was born in Edinburgh, Scotland, on 3 March 1847. His mother, Elisa Grace Symonds, was a portrait painter and an accomplished musician. His father, Alexander Melville Bell, taught deaf-mutes to speak, and wrote textbooks on correct speech. He invented "Visible Speech," a code of symbols which indicated the positions of the throat, tongue , and lips in making sounds, and helped guide the deaf in learning to speak. Bell and his two brothers assisted their father in public demonstrations of "Visible Speech," beginning in 1862. He also enrolled in a school near Edinburgh, where he taught music and speech in exchange for instruction in other subjects at school. He became a full-time teacher after studying for a year at the University of Edinburgh.

Bell's family experienced the tragic deaths of Bell's oldest and youngest brothers to tuberculosis, and therefore hastily moved to Tutelo Heights near Brantford in Ontario, Canada, in 1870, to escape the fogs of England. Bell's father was contacted by the Board of Education in Boston, Massachusetts to teach deaf children to speak based upon his "Visible Speech" system. He turned the offer over to his son, Graham, who started a successful teaching practice.

Bell was encouraged in his research by Joseph Henry, of induction and magnetism renown, and by Sir William Thompson (Lord Kelvin). Bell showed Henry his discovery that passing an intermittent current through a helix of insulated copper wire could produce the pitch, but not the quality, of sound. Henry encouraged Bell to pursue his research and also to master the fundamentals of electricity. Sir William Thompson was later to witness Bell's demonstration of the "electric speaking telephone" at the Philadelphia Centennial Exhibition in 1876, and thought it to be 'the greatest by far of all of the marvels of the electric telegraph."

Bell's invention of the telephone was a step-by-step process, sometimes with despair that the invention could succeed. During a period of recuperation at Tutelo Heights from his strenuous workload of teaching and inventing, he contemplated the phonautagraph, a sound writer that could receive sound waves on a membrane stretched over a hollow cylinder, and then move a stylus in sympathy with the vibrations. Bell's sudden insight was that a receiver modeled closely to the human ear might produce more accurate tracings of speech vibrations. He also experimented with the harmonic multiple telegraph in which a number of telegraph signals could be sent simultaneously over the same circuitry in either or both directions. For this invention he first used a tuning fork (later substituting a tuned steel reed) with its prong placed between the poles of an electromagnet, producing a dc electric current at each vibration. By operation of a telegraph key in the circuit of each fork, the intermittent current, controlled by the vibration of that particular fork, could be sent over a telegraph line wire to a receiving end where a similar fork, tuned to the same pitch, would be actuated by an electromagnet. Only the fork tuned to that pitch would "receive" the signal. A similar system was used for remote control of substation equipment as "supervisory control" in recent years.

Bell was materially aided by Thomas A. Watson, who was adept at building electrical apparatus. On 2 June 1875, Bell, assisted by Watson, was experimenting with the multiple telegraph - Watson sending, Bell receiving. One of the tuned-reed transmitters, which was in close proximity to the pole of an electromagnet, fused its contacts. Bell heard the faint echo of the vibrating fused reed, and then realized the idea of an undulating current that could transmit sound by electrical wire. Bell was then working on a spark arrester for the multiple telegraph, and he regulated the resistance between the two wires by dipping their ends into a vessel of water, varying the resistance by adjusting the depths to which the wires were submerged. From this came the idea of producing undulating current stronger than those obtained from his magneto-electric instrument. As the diaphragm vibrated, the wire rose and fell subject to its control, and by varying the resistance, varied the magnitude of the current. With this apparatus, a test was made on 10 March 1876. Bell spoke and Watson heard the first sentence transmitted by the telephone, "Mr. Watson come here, I want you."

Bell and Watson made many successful demonstrations on the telephone, and their work paved the way for the beginning of telephone service in America. The first telephone company, the Bell Telephone Company, came into existence on 9 July 1877. Shortly after, Bell married Mabel Hubbard and sailed with his bride to England to introduce the telephone there.

Bell returned to America in 1878, and moved to Washington, D.C. He did not take an active part in the telephone business, although he was frequently called upon to testify in lawsuits brought by men claiming they had invented the telephone earlier. Several suits reached the Supreme Court of the United States. The Court upheld Bell's rights in all the cases.

Bell lived a creative life for more than 45 years after the invention of the telephone. He gave many years of service to the deaf, and produced other communication devices.

The French government awarded Bell the Volta prize of 50,000 francs in 1880 for his invention of the telephone. He used the money to help establish the Volta Laboratory for research, invention, and work for the deaf. There he and his associates also developed the method of making phonograph records on wax discs. He was awarded the IEEE (AIEE) Edison Medal in 1914 for "For meritorious achievement in the invention of the telephone."

Bell spent most of his later life at his estate on Cape Breton Island, Nova Scotia. He worked in his laboratory, or sat at his piano playing old Scottish tunes. He became a citizen of the United States in 1882. He died on 2 August 1922 in near his Nova Scotia home.



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Citation

Engineers, I. (2008). Bell, Alexander Graham. Retrieved from http://editors.eol.org/eoearth/wiki/Alexander_Graham_Bell