Which invention did Thomas Edison first test by reciting “Mary Had a Little Lamb”?

In 1877, at his laboratory in Menlo Park, New Jersey, Thomas Edison built a machine with a needle that cut grooves into tinfoil wrapped around a cylinder. He shouted the nursery rhyme into it, then played it back. To everyone’s amazement, the machine repeated his words.

The phonograph made Edison famous, and newspapers called him “the Wizard of Menlo Park.” Two years later, his team produced a long-lasting practical light bulb.

Edison held 1,093 U.S. patents, more than any other American of his time. He liked to say genius was one percent inspiration and ninety-nine percent perspiration.