Alexander Graham BELL (1847-1922), He worked for a long time to support the deaf since that is what his father did. He moved to London at the age of 15, and lived there with his grandfather who taught him the techniques of speech therapy. He designed a “harmonic telegraph,” a kind of piano that could transmit music over a distance. In 1872, following his father, he secured a position at the Boston School for the Deaf and Dumb and subsequently opened a School of Vocal Physiology and Speech Mechanics. This gave him enough financial security to continue his research into ways of transmitting articulate sounds, and speech at a distance, using cables and electricity. He marries a woman who has audio problems and begins his development in the area of telecommunications. On March 10, 1876, BELL had already developed. With it he transmitted to his assistant, who was in another room: “Mr. Watson, come here, I want to see you.” That same year, 1876, he presented at the World’s Fair in Philadelphia, celebrating the First Centennial of the Declaration of Independence of the United States. The exhibition, from May 9 to November 10, was visited by 9,789,392 people. Lord Kelvin (William Thompson), eminent physicist, present as a judge issuing reports on the precision instruments, research and illustration presented, together with Joseph HENRY, scientist. Both wrote some of the 385 reports. He is one of the scientists with high recognition as a businessman. The Bell Telephone Company is currently the renowned AT&T.