2022Science - Thomas Alva Edison - Set

Alexander Graham Bell - scientist, inventor and founder of the Bell Telephone Company. In addition to his work in the field of communications, he is responsible for important inventions in aviation. He researched the mechanics of speech, so in 1872 he founded a school for teachers for the deaf-mute in Boston. While teaching at this school, he constructed an artificial ear that registers tones on a shaded glass plate. He invented the electric telephone in 1876. This invention has been improved several times, and has been in use since 1877. He also constructed a photophone, which works on the principle of converting changes in light intensity into sound. He proposed the use of wax for phonograph records and found an electrical method for detecting metallic objects in the human body. Preoccupation with his mother's deafness led him to study acoustics and to develop the technique of speaking in clear, modulated tones directly into his mother's forehead. Bell's father taught him and his brothers not only to write visible speech, but also to recognize any symbol and accompanying sound.