Alexander Graham Bell
Alexander Graham Bell (March 3, 1847 - August 2, 1922) was a teacher, scientist, and inventor. He was the founder of the Bell Telephone Company.
Alexander Graham Bell was born in Edinburgh, Scotland. His family was known for teaching people how to speak English clearly (elocution). Both his grandfather, Alexander Bell, and his father, Alexander Melville Bell, taught elocution. His father wrote often about this and is most known for his invention and writings of Visible Speech. In his writings he explained ways of teaching people who were deaf and unable to speak. It also showed how these people could learn to speak words by watching their lips and reading what other people were saying.
Alexander Graham Bell went to the Royal High School of Edinburgh. He graduated at the age of fifteen. At the age of sixteen, he got a job as a student and teacher of elocution and music in Weston House Academy, at Elgin in Morayshire. He spent the next year at the University of Edinburgh. While still in Scotland, he became more interested in the science of sound (acoustics). He hoped to help his deaf mother. From 1866 to 1867, he was a teacher at Somersetshire College in Bath, Somerset.
In 1870 when he was 23 years old, he moved with his family to Canada where they settled at Brantford, Ontario. Bell began to study communication machines. He made a piano that could be heard far away by using electricity. In 1871 he went with his father to Montreal, Quebec in Canada, where he took a job teaching about "visible speech". His father was asked to teach about it at a large school for deaf mutes in Boston, Massachusetts, but instead he gave the job to his son. The younger Bell began teaching there in 1871. Alexander Graham Bell soon became famous in the United States for this important work. He published many writings about it in Washington, D.C.. Because of this work, thousands of deaf mutes in America are now able to speak, even though they cannot hear.
In 1876, Bell was the first inventor to patent the telephone, and he helped start the Bell Telephone Company with others in July 1877. In 1879, this company joined with the New England Telephone Company to form the National Bell Telephone Company. In 1880, they formed the American Bell Telephone Company, and in 1885, American Telephone and Telegraph Company (AT&T), still a large company today. Along with Thomas Edison, Bell formed the Oriental Telephone Company on January 25, 1881.
Bell's genius is seen in part by the eighteen patents granted in his name alone and the twelve that he shared with others. These included fifteen for the telephone and telegraph, four for the photophone, one for the phonograph, five for aerial vehicles, four for hydroairplanes, and two for a selenium cell.
In 1888, he was one of the original members of the National Geographic Society and became its second president.
He was the recipient of many honors.
- The French government gave him the decoration of the Legion of Honor.
- The Royal Society of Arts in London awarded him the Albert medal in 1902.
- The University of Würzburg, Bavaria, granted him the Degree of Ph.D.
His past experience made him ready to work more with sound and electricity. He began his studies in 1874 with a musical telegraph, in which he used an electric circuit and a magnet to make an iron reed or tongue vibrate. One day, it was found that a reed failed to respond to the current. Mr. Bell desired his assistant, who was at the other end of the line, to pluck the reed, thinking it had stuck to the magnet. His assistant, Thomas Watson complied, and to his surprise, Bell heard the corresponding reed at his end of the line vibrate and sound the same - without any electric current to power it. A few experiments soon showed that his reed had been set in vibration by the changes in the magnetic field that the moving reed produced in the line. This discovery led him to stop using the electric battery current. His idea was that, since the circuit was never broken, all the complex vibrations of speech might be converted into currents, which in turn would reproduce the speech at a distance.
Bell, with his assistant, devised a receiver, consisting of a stretched film or drum with a bit of magnetised iron attached to its middle, and free to vibrate in front of the pole of an electromagnet in circuit with the line. This apparatus was completed on June 2, 1875. On July 7th, he instructed his assistant to make a second receiver which could be used with the first, and a few days later they were tried together, at each end of the line, which ran from a room in the inventor's house at Boston to the cellar underneath. Bell, in the room, held one instrument in his hands, while Watson in the cellar listened at the other. The inventor spoke into his instrument, "Do you understand what I say?" and Mr. Watson rushed back into the upstairs and answered "Yes." The first successful two-way telephone call was not made until March 10, 1876 when Bell spoke into his device, "Mr. Watson, come here, I want to see you." and Watson answered back. The first long distance telephone call was made on August 10, 1876 by Bell from the family home in Brantford, Ontario to his assistant located in Paris, Ontario, some 16 km (10 mi.) away.
After that, Bell continued his experiments in communication, which led to the invention of the photophone – which sent sound on a beam of light. Bell worked with Charles Sumner Tainter. In his paper on the photophone, Bell gave credit to A. C. Browne of London with his discovery in 1878. Bell and Tainter, however, were the first to perform a successful experiment. It was not an easy task, as they had to produce selenium cells with the desired properties themselves.
In one experiment in Washington, D.C., the sender and the receiver were placed in different buildings some 830 ft. (about 250 meters) apart. The sender had a mirror directing sunlight onto the mouthpiece, where the light beam was changed by a vibrating mirror. It was focused by a lens and sent at the receiver, which was a curved mirror with the selenium cells in the focus and a headphone attached. With this setup, Bell and Tainter succeeded in voice communication by lighbeams.
The photophone was patented on December 18, 1880. However, since the light beam was not shielded in any way against external interference, the quality of communication was not always good, and it only worked within line-of-sight. It is still considered a forerunner of the much later fiber optic technology, which is based on the same ideas, but which removed those limits.
Metal detector [change]
Bell is also credited with the invention of an improved metal detector in 1881 that made sounds when it was near metal. The device was quickly put together in an attempt to find the bullet in the body of U.S. President James Garfield. The metal detector worked, but did not find the bullet because of the metal bedframe the President was lying on. Bell gave a full description of his experiments in a paper read before the "American Association for the Advancement of Science" in August, 1882.
Bell was an active supporter of the eugenics movement in the United States. He was the honorary president of the "Second International Congress of Eugenics" held at the American Museum of Natural History in New York in 1921. He did not want deaf people to be allowed to teach in schools for the deaf. He was also against the use of sign language. These things mean that he is not appreciated by some deaf people in the present day.
Other websites [change]