What is Photophone?
The '''photophone''' is a [[telecommunication]]<nowiki/>s device that allows transmission of speech on a beam of light. It was invented by [[Alexander Graham Bell]] along with his assistant [[:en:Charles_Sumner_Tainter|Charles Sumner Tainter]] on February 19, 1880. Bell believed that the photophone was his most important invention. [[Category:Telecommunications]] [[Category:1880]]