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.
বেল এবং টেন্টার দুজনেই কোন ল্যাব অ্যাসোসিয়েশনে যোগ দিয়েছিলেন?
Volta Laboratory Association