By Robert M. Yoder
Dec. 21, 1946
The Saturday Evening Post

He knocked one off his desk one day ashore, and noted idly that it bounced around like a tumbler. Put on an inclined plane, it would walk down, like an acrobat doing slow flips, looking like some futuristic steel worm of the twenty-first century. James‘ son, Tommy, liked one as a plaything. So did a neighbor boy who came down with measles. So did other children. The engineer had a vague feeling that he ought to do something with this device, but it was Tommy who showed him the possibilities. The boy put one on the steps of their home, pulled the top of the spring down to the next step, and to James’ surprise this talented hardware walked gravely down, throwing itself into a loop, it landed on its head, lifted its tail, threw itself sedately into another loop to reach the step below. James immediately set out to design a toy in which this trick would be perfected.

Slinky Has Done Very Nicely by its Inventor

A piston-ring company manufactured a few for him in the fall of 1944, but toy dealers weren't interested. Less than a month before Christmas a department store phoned to say James could use the end of one counter, but would have to serve as salesman. No little embarrassed, he and his wife turned clerks on November twenty-seventh and sold their entire supply - 400 - in ninety minutes. In the last few weeks of the year the toy made more money for them than James had earned all year in a good engineering job. By Christmas 22,000 had been sold, and by October of this year James was manufacturing 22,000 a week. He had sold 430.000, had his own business, his own little factory, and had quit marine engineering cold.

The toy he designed is not technically a spring, but a coil. A flat ribbon of steel seventy-nine feet long is wound so that the loops have zero tension or compression-—a Monday condition in which they would as soon fall together as fall apart. The result—called "Slinky"- looks like a stack of piston rings. That’s all there is to it, yet at a dollar a copy Slinky has performed very handsomely for its inventor. With the proceeds of an idea that fell off his desk, the thirty-year-old Philadelphian not only is launched on a manufacturing career which he likes very much, but could afford a little flier at a sport tried out last summer at Atlantic City. Sporting bloods who will gamble with anything were racing Slinkys.