THOMAS EDISON VIDEO

http://www.youtube.com/watch?v=F2id0hZxxiw&feature=related

ALEXANDER GRAHAM BELL (1847-1922)

Bell was born into a family specialising in elocution: both his father and his grandfather were authorities on the subject, and before long he himself was teaching people how to speak. Largely family trained and self-taught, in 1863, at the age of 16, he and his brother Melville began researching the mechanics of speech. Starting with the anatomy of the mouth and throat, they sacrificed the family cat in order to study the vocal chords in more detail.

In 1864 Bell became a resident master in Elgin's Weston House Academy in Scotland, where he conducted his first studies in sound and first conceived the idea of transmitting speech with electricity. His idea was to make a device that could mimic the human voice and reproduce vowels and consonants. His father had already spent years classifying vocal sounds and had developed a shorthand system called Visible Speech, in which every sound was represented by a symbol, with the intention of teaching the deaf to speak by putting these sounds together.

The onset of tuberculosis, which killed his two brothers, prompted a family move to Canada in 1870 so that he could recuperate. After spending some time in Boston, lecturing and demonstrating the Visible Speech system, he chose to settle there in 1872. He opened his own school to train teachers for the deaf, edited his pamphlet Visible Speech Pioneer, and continued to study and teach, becoming professor of vocal physiology at Boston University in 1873. The idea of transmitting speech along a wire never left him, and after considerable research and many false dawns, by 1875 he had come up with a simple receiver that could turn electricity into sound.

Others were also working to invent such a device, among them an Italian immigrant to America, Antonio Meucci. He was ready to patent his 'teletrofono' in 1871, but could not raise the sum necessary. The dispute continues as to who should be credited with the invention of the telephone, although in 2002 the US Congress made a statement recognising retrospectively that it was Meucci who was first with the idea - a statement that continues to provoke argument.

On 6 April 1875, however, it was Bell who was granted the patent for his multiple telegraph, and he also continued work on his telephone. The final breakthrough was an accident that occurred while testing a circuit with one transmitter and two receivers on 2 June 1875. The transmitter was switched off and Watson was adjusting one of the receivers when Bell heard a note coming from the receiver in his room. With the transmitter turned off, the note had to be coming from the other receiver. He had discovered that the receiver could also work in reverse: instead of making sound when electricity was sent through it, it also made electricity when supplied with sound because the sound moved the magnet in the coil and generates electricity. More importantly, the electricity varied with the voice.

Bell developed his system and submitted his patent on 14 February 1876, just two hours before Elisha Gray, seemingly his strongest rival. The patent was granted on 7 March, and was possibly the most valuable patent ever issued: over 600 law suits followed before a Supreme Court decision ruled in Bell's favour in 1893. Developments were swift. Within a year the first telephone exchange was built in Connecticut and within the decade more than 150,000 people in the US alone owned telephones. The Bell Telephone Company was created in 1877, with Bell the owner of a third of the 5,000 shares. Stock in the company soared from $50 to over $1,000 a share within three years.

Bell was not yet 30 years old. Now a resident of Washington, DC, he continued his experiments in communication, in medical research, and in techniques for teaching speech to the deaf. In 1880 France awarded him with the Volta Prize, worth approximately 50,000 francs (around $10,000), and he used the money to finance the Volta Laboratory where, in association with Charles Sumner Tainter, he invented the Graphophone. His share of the royalties from this invention financed the Volta Bureau and the Alexander Graham Bell Association for the Deaf.

His soaring stock in the Bell Telephone Company had made him a man of independent means. In 1885 he acquired land on Cape Breton Island in Nova Scotia. In surroundings reminiscent of his early years in Scotland, he established a summer home there, complete with research laboratories. Here he continued his work with deaf people - including a young Helen Keller - and continued to invent, although lightning would not strike again. He made peculiar aircraft with wings based on triangles, he built the forerunner to the iron lung, and he experimented with sheep. He was convinced that sheep with extra nipples would give birth to more lambs, and built a huge village of sheep pens, spending years counting sheep nipples, before the US State Department announced that extra nipples were not linked with extra lambs.

In 1898 Bell succeeded his father-in-law as president of the National Geographic Society. He believed that geography could be taught through pictures, and so sought to promote a more common understanding of life in distant lands for the vast majority of people who could not afford to travel. Gilbert Grosvenor, his future son-in-law, eventually transformed a modest pamphlet into the groundbreaking National Geographic Magazine - an educational journal that today reaches millions worldwide.