Joseph Henry, The American Pioneer in Electrical Communication

Joseph Henry The American Pioneer in Electrical Communication B y B A N C R O F T G H E R A R D I and R O B E R T W . K I N G N the brilliant galaxy of investigators to whom we owe our knowledge of electrical science, Joseph Henry stands out as of the first magnitude; and for those who are associated with the Bell System, the present is a most appropriate time to review his researches which had an important guiding influence on the development of electrical communication. The present year marks the fiftieth since the invention of the telephone by Alexander Graham Bell, and among the scientists with whom Bell conferred at that time, he gave a place of honor to Henry. In a letter to his parents written in March, 1875, while he was busy in an effort to perfect the harmonic telegraph, and before he had turned his attention to the telephone, Bell wrote: "Now to resume telegraphy. When I was in Washington, I had a letter of introduction to Professor Henry, who is the Tyndall of America. I had found on inquiry at the Institute of Technology, that some of the points I had discovered in relation to the application of acoustics to telegraphy had been previously discovered by him. I thought I would, therefore, explain all the experiments, and ascertain what was new and what was old. He listened with an unmoved countenance, but with evident interest to all, but when I related an experiment that at first sight seems unimportant, I was startled at the sudden interest manifested. "I told him that on passing an intermittent current of electricity through an empty helix of insulated copper wire, a noise could be heard proceeding from the coil, similar to that heard from the telephone.