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.”

Kinetoscope (peep hole viewer)

Kinetograph (motion picture camera)

Stock Ticker

First Commercial Fluoroscope

Electricity Distribution System

Carbon Microphone

Quadruplex, Aextuplex and Multiplex Telegraph

Electrical Vote Recorder

Durable light bulb (40 hours)

Phonograph