What walks down stairs, alone or in pairs?

Today we celebrate the invention of a precompressed helical spring – you might know it as SLINKY!

It was invented by a naval engineer in the 1940s who was working with tension springs, in an effort to try to suspend shipboard instruments, one of the springs fell off his shelf and kept going – the idea to turn it into a toy was born.

His wife Betty came up with the name after flipping through the dictionary and thought the word described how the toy moved.

Richard had secured a $500 loan to develop a coil winding machine to mass produce the toy and they created 400 of them for Gimbels Department Store in time for Christmas 1945. After putting the slinky on an inclined ramp display at the department store, all 400 Slinkys sold out in 90 minutes for a $1 each.

Since then over 300 million Slinkys have been sold world-wide.