Melville and Alexander were brothers. Their father used to teach hearing and speech impaired children to communicate. He encouraged his sons to study how humans produced sound, and then challenged them to build a model. So Melville and Alexander designed a “speaking machine”, with Melville creating the throat and larynx out of tin tubes and pieces of rubber, and Alexander using a human skull as his model to create the jaw, tongue, and palate. Clever use of levers made the tongue move. Melville blew into the tin tube while Alexander moved the tongue and the lips. After much practice, trial, and error, the boys got their contraption to say “Mamma”. And when it did, they heard a neighbour call out, “What’s the matter with that baby?” It was a success!
Sounds and vibrations
When Alexander Graham Bell was 19, he read about the work of German scientist Hermann von Helmholtz, who had carried out many experiments with sound and electricity. There was just one problem — all of Helmholtz’s papers were in German, and Bell was not very familiar with the language. Still, he plodded through, and what he understood made him excited. He thought that Helmholtz had proved that sound could be transmitted via an electric line! In fact, Helmholtz had only started work in that area, and was far from the proof. But thanks to a shaky grasp of German combined with wishful thinking, Bell stuck to this belief and immediately launched a series of experiments with sound and electricity.
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Bell knew about sending telegraphic clicks over electrical lines. That had been done 40 years earlier. But human speech was a lot more complicated than clicks. Sound travelled in waves — if you have two paper cups connected together by a taut string, and you speak into one of the cups, the sound reaches the other by way of mechanical vibrations over the string. Bell only had to find a way of creating an electrical wave that would follow exactly the same wave as a person’s speech. This electrical wave could then be transmitted over a wire connected to a receiver.
Just as he had used the human skull all those years ago, Bell studied a dead man’s ear to understand how vibrations could be transmitted. Said Bell, “As I was holding the human ear in my hand, it struck me that the ear membrane was like a little piece of tissue paper, hardly the size of a fingernail, and the bones that were moved by the little membrane were really very heavy… Could I not use a larger membrane to move a piece of metal?”
He put all these ideas together on the morning of March 10, 1876. His apparatus was a “liquid transmitter” that used vinegar as the conducting medium for electricity. The tip of a wire was carefully placed on the surface of a cup of vinegar, hardly touching it. The other end of the wire was connected to a membrane stretched over a cone. Into the cone, Bell spoke the words, “Mr. Watson, come here, I want to see you!” The membrane vibrated, and caused the wire to dip into and out of the vinegar, in perfect step with the vibrations. These vibrations were carried over the electrical wire to a receiver in the hands of his assistant Thomas Watson, who was sitting in a room down the hall. Watson heard every word, clear as bell. The first telephone call was made.
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In his final version, Bell replaced the vinegar transmitter with an electromagnetic circuit, making the machine easy to move and install.
It was in August 1876 that the technology was perfected, and the first long distance call was made in Ontario with telephones placed 10 miles apart.
Did you know?
Bell was one of the founders of the National Geographic Society and its second president.
Bell’s mother lost her hearing when Bell was 12. So he was always thinking of ways to communicate with the hearing impaired. He became a teacher for speech and hearing impaired children, and his most famous pupil was Helen Keller.
An antique phone from the 1920s would work just fine if you connected it to the wall jack in your house, because landline technology has remained the same for nearly a century!
After successfully inventing the telephone, Alexander Graham Bell refused to have one in his study, fearing it would distract him from his scientific work.
A fictionalised biographical film made on Alexander Graham Bell in 1939 shows a scene where the acid from Bell’s liquid transmitter spills on his trousers and he shouts to Watson for help. Watson hears the words over the telephone line and runs into the room excitedly. However, Bell’s notes as on March 10, 1876 make no mention of this incident and its truth has not been verified.