Slinky

The Slinky is a coil of flat steel wire, wound so tightly that at rest it sits in the hand as a short, solid cylinder a little under three inches across. Set at the top of a stair and tipped over, it walks: the upper end arcs over onto the step below, the rest of the coil pours after it, and the motion begins again, step after step, with a soft metallic rattle. It has no motor and no mechanism. The whole trick is the steel and its tension.

Richard James found it by accident. In 1943 he was a naval engineer in Philadelphia, working on springs to keep instruments steady aboard ship, when a spring knocked from a shelf stepped its way down instead of falling. It took him about a year of trying different wire to find one that would walk every time, and his wife Betty found the name in a dictionary. They borrowed $500, built a machine to coil the wire, and began making the toy in Clifton Heights, Pennsylvania.

Toy shops were not interested until Gimbels in Philadelphia let them set up an inclined plane in the toy department in late November 1945. The first 400 sold in ninety minutes at a dollar each. The toy went to the American Toy Fair the next year, and in its first sixty years about 300 million were sold. When Richard left for Bolivia in 1960, Betty ran the company herself, moved it to Hollidaysburg, Pennsylvania, and kept the price low so that poorer children could have one.

She sold the business in 1998, and the Slinky has since passed through several owners, most recently Just Play, which bought the brand in 2020. Production stayed in Hollidaysburg after the first sale. Plastic, rainbow and dog-shaped versions have been added around it, but the metal coil is still sold as the Original Slinky, and it still walks downstairs.