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, he 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. He 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 the trade name for Edison's device, which played cylinders rather than discs. The machine had two needles: one for recording and one for playback. When you spoke into the mouthpiece, the sound vibrations of your voice would be indented onto the cylinder by the recording needle. This cylinder phonograph was the first machine that could record and reproduce sound created a sensation and brought Edison international fame.
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