Thomas Edison

The first great invention developed by Edison in Menlo Park was the tin foil phonograph.

While working to improve the efficiency of a telegraph transmitter, Edison noted that the

tape of the machine gave off a noise resembling spoken words when played at a high speed.

This caused him to wonder if he could record a telephone message. Edison began

experimenting with the diaphragm of a telephone receiver by attaching a needle to it. He

reasoned that the needle could prick paper tape to record a message. His experiments led him

to try a stylus on a tinfoil cylinder, which, to his great surprise, played back the short

message he recorded, "Mary had a little lamb."

The word, "phonograph," was Thomas Edison's trade name for his device,

which played cylinders rather than discs. The machine had two needles:

one for recording and one for playback. When Edison spoke into the

mouthpiece, the sound vibrations of his voice would be indented onto the

cylinder by the recording needle. The first machine that could record and

reproduce sound created a sensation and brought Edison international

August 12, 1877, is the date popularly given for Thomas Alva Edison's

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