Alexander Graham Bell invented a wireless telephone, named a photophone which allowed for the transmission of both sounds and normal human conversations on a beam of light.
On June 21, 1880, Bell transmitted a wireless voice telephone message a considerable distance, 19 years before the first voice radio transmissions.
Bell believed the photophone's principles were his life's "greatest achievement", telling a reporter shortly before his death that the photophone was "the greatest invention [I have] ever made, greater than the telephone".
The photophone was a precursor to the fibre-optic communication which achieved popular worldwide usage in the 1980s. Its master patent was issued in December 1880, a century before the photophone's principles came into popular use.