Alexander Graham Bell and the invention of the telephone

The essentials of the telephone receiver were invented before Bell´s work. A primitive telephone transmitter was invented by Philip Reis in 1860. Others claimed to have anticipated Bell´s invention, but their claims were unsuccessful in the US law courts. The paper shows how Bell´s work on the harmonic telegraph led to his first idea for a telephone, and his experiments in telephony, which resulted in intelligible speech transmission in 1876, are described. The work of Elisha Gray is also described. The paper includes subsequent developments in telephony up to 1881, and Bell´s later scientific activities and work for the deaf are also reviewed.