Granny's Notes ; Telephone Worked Well, Even If You Had a Tin Ear

Summary

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In my day, most kids I knew used two tin cans and a long cord to make a telephone that actually worked. We punched a small hole in the center of the can bottoms and poked one end of the cord into each hole. Then we tied knots to keep the cord from coming out. By stretching the cord tight we could communicate quite well at surprisingly long distances. We talked and listened into the open end of the cans. Each can was both transmitter and receiver. Two of my classmates talked with each other from their second-floor rooms across Maryland Avenue in Columbia!

I was surprised to find reference to string telephones in Johnson's 1876 "Universal Cyclopedia: A Treasury of Useful Knowledge," The writer said, "The string telephone was mentioned as early as 1667 by a German named Robert Hooke," who assured us that "the theory of the telephone is simple."

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Granny's Notes ; Telephone Worked Well, Even If You Had a Tin Ear

The string telephone transmitted sound waves mechanically, and it was 200 years later that a German, Johann Phillip Reis, transmitted sou...

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