Slinky was the invention of Richard James, a mechanical engineer in the United States Navy. In 1943 he was looking for a way to lessen the vibrations that sensitive equipment endured shipboard in rough waters. An accident during his experiments led to the creation of a "walking", tumbling metal spring. Neighborhood children loved it. James's wife Betty named the toy Slinky after finding the word in a dictionary. The Jameses had 400 Slinkys made by a local machine shop. The Jameses put Slinky on display at Gimbels department store in Philadelphia in November 1945. All 400 units were sold.