The Edison effect and its modern applications

WE are so accustomed to thinking of Thomas A. Edison as the father of the incandescent lamp and of the electric lighting industry that we sometimes forget that his first achievements were in the field of the electrical communication of intelligence, and that in this field he is no less distinguished. To say nothing of his inventions in multiplex and automatic telegraphy, it is well to recall that the field of telephony owes no less to the fundamental inventions of Mr. Edison than to those of Alexander Graham Bell. Bell, it is true, invented the telephone receiver of today, but Edison invented the transmitter, and afterwards invented a highly efficient receiver on a principle entirely different from that of Dr. Bell´s.