Bell and his assistant Charles Sumner Tainter jointly invented a wireless telephone, named a photophone, which allowed for the transmission of both sounds and normal human conversations on a beam of light. Both men later became full associates in the Volta Laboratory Association.
Bell and his assistant Charles Sumner Tainter jointly invented a wireless telephone , named a photophone , which allowed for the transmission of both sounds and normal human conversations on a beam of light . Both men later became full associates in the Volta Laboratory Association .
What did Bell's cord-free phone use to transmit messages?
What did Bell 's cord - free phone use to transmit messages ?
light
light