How the Slinky Was Accidentally Invented

One day he knocked a spring off a shelf. Instead of collapsing in a heap, it stepped gracefully downward—from shelf to books to tabletop to floor—where it coiled itself upright and stood still. James stared at it, then did it again.

His wife Betty recognized what he didn't: this wasn't a failure. This was a toy. She spent hours with a dictionary looking for the right name and landed on "slinky," meaning sleek and sinuous in movement. They took out a $500 loan, founded James Industries, and Richard worked out the specifications—80 feet of wire coiled into a two-inch spiral.

In 1945, Gimbels Department Store in Philadelphia let them set up an inclined plane in the toy section for a demonstration. They sold 400 units in ninety minutes. Within a year, the Slinky was in toy stores across America.

The story could have ended there, but it didn't. In 1960, Richard James abruptly left his wife and six children to join a religious cult in Bolivia. He died in 1974, having given away much of the company's money to the organization. Betty James was left to run the business alone, which she did for the next four decades. She moved operations to Hollidaysburg, Pennsylvania, and launched the television advertising campaign that made the Slinky jingle one of the most recognized in American marketing.

The toy found uses its inventors never anticipated. Physics teachers use it to demonstrate wave properties. U.S. troops in Vietnam stretched Slinkys between trees as makeshift radio antennas. NASA has taken them to space for zero-gravity experiments.

Over 300 million Slinkys have been sold—enough, stretched end to end, to circle the Earth about 150 times. All from a spring that fell off a shelf the wrong way.