Wednesday, August 13, 2008
Alexander Graham Bell's Telephone
Alexander Graham Bell constructed this prototype telephone in 1875. The device consists of a coil of wire, a magnetic arm and a taut membrane. Any sound causes the membrane, and hence the magnetic arm, to vibrate. The movement of the magnet induces a fluctuating electric current in the coil. This electrical signal can be reconverted into sound by an identical apparatus at the other end of the circuit. |
ALEXANDER GRAHAM BELL BIOGRAPHY
Alexander Graham Bell might easily have been content with the success of his telephone invention. His many laboratory notebooks demonstrate, however, that he was driven by a genuine and rare intellectual curiosity that kept him regularly searching, striving, and wanting always to learn and to create. He would continue to test out new ideas through a long and productive life. He would explore the realm of communications as well as engage in a great variety of scientific activities involving kites, airplanes, tetrahedral structures, sheep-breeding, artificial respiration, desalinization and water distillation, and hydrofoils.
With the enormous technical and later financial success of his telephone invention, Alexander Graham Bell's future was secure, and he was able to arrange his life so that he could devote himself to his scientific interests. Toward this end, in 1881, he used the $10,000 award for winning France's Volta Prize to set up the Volta Laboratory in Washington, D.C. A believer in scientific teamwork, Bell worked with two associates, his cousin Chichester Bell and Charles Sumner Tainter, at the Volta Laboratory. Their experiments soon produced such major improvements in Thomas Edison's phonograph that it became commercially viable. After 1885, when he first visited Nova Scotia, Bell set up another laboratory there at his estate, Beinn Bhreagh (pronounced Ben Vreeah), near Baddeck, where he would assemble other teams of bright young engineers to pursue new and exciting ideas.
Among one of his first innovations after the telephone was the "PHOTOPHONE," a device that enabled sound to be transmitted on a beam of light. Bell and his assistant, Charles Sumner Tainter, developed the photophone using a sensitive selenium crystal and a mirror that would vibrate in response to a sound. In 1881, they successfully sent a photophone message over 200 yards from one building to another. Bell regarded the photophone as "the greatest invention I have ever made; greater than the telephone." Alexander Graham Bell's invention reveals the principle upon which today's LASER and FIBEROPTIC communication systems are founded, though it would take the development of several modern technologies to realize it fully.
Alexander Graham Bell |
Over the years, Alexander Graham Bell's curiosity would lead him to speculate on the nature of heredity, first among the deaf and later with sheep born with genetic irregularities. His sheep-breeding experiments at Beinn Bhreagh sought to increase the numbers of twin and triplet births. Bell was also willing to attempt inventing under the pressure of daily events, and in 1881 he hastily constructed an electromagnetic device called an induction balance to try and locate a bullet lodged in President Garfield after an assassin had shot him. He later improved this and produced a device called a telephone probe, which would make a telephone receiver click when it touched metal. That same year, Bell's newborn son, Edward, died from respiratory problems, and Bell responded to that tragedy by designing a metal vacuum jacket that would facilitate breathing. This apparatus was a forerunner of the iron lung used in the 1950s to aid polio victims. In addition to inventing the audiometer to detect minor hearing problems and conducting experiments with what today are called energy recycling and alternative fuels, Bell also worked on methods of removing salt from seawater.
Photograph of the |