On November 29, 1877, Thomas Edison first demonstrated his phonograph, an invention he had been working on for a surprisingly short amount of time. While he’s a household name today mostly due to his revolutionary advances in lightbulb technology and motion pictures, at this point Edison was still a relatively unknown inventor and tinkerer operating out of Elizabeth, New Jersey. Edison had been trained as a telegraph operator, and had transitioned to being an inventor when he began coming up with various improvements on telegraph technology. It was one of his inventions, the quadruplex telegraph that allowed for four signals to be carried on a single telegraph wire at a time, that was wildly successful and financed the construction of his innovation lab at Menlo Park.
With his lab constructed, Edison began to branch out in his focus. In early 1877 he began experimenting with recording and playing back telegraph messages. This spurred the idea that if he could record telegraph messages, using the same basic idea he could also record a spoken voice. Essentially, by using electromagnets to convert the voice into an analog signal, he could manipulate the position of a stylus in sync with the spoken voice. He then created an apparatus that would place this stylus up against a rotating cylinder sheathed in a thin covering of tinfoil, which would be easily indented by the pointy tip of the stylus. The resulting indentations on the tinfoil cylinder reflected the pitch and volume variations of the voice and could be played back over and over.
Edison’s phonograph was astonishing. While his earlier inventions of stock tickers and telegraph technologies had been important and groundbreaking, this phonograph was something many at the team hadn’t even considered a possibility. He went on tour to demonstrate the technology, showing it personally to numerous Senators and even the President, all of whom were extremely impressed with both Edison and the technology. Ultimately, Edison didn’t develop the phonograph much further than his basic tinfoil cylinders as his focused turned to the electric light and other, more lucrative ventures. Other innovators began to improve on Edison’s early prototype, which used unwieldy and fragile cylinders, by introducing a flat disc that was easier to transport and even had more capacity for recordings. While he wasn’t responsible for the popularization of the phonograph, or even the designs today’s technology arose from, Edison can add inventing the recording of sounds to his long list of achievements.