io9 über die Geschichte des Hop Rod, einem motorisierten Pogo Stick:
It seems that the first US patent for an internal-combustion powered ‘Pogo' stick was issued to inventor R.J. Mays back in 1950.
The jumping machine was intended to run on gasoline, and, according its creator was "…highly efficient and amusing in operation." It's not altogether clear whether May's power-stick ever went into production, but a similar(ish) device, which was granted a US patent ten years later, did. According its inventor Mr. G. Spitzmesser, the stick – known commercially as ‘The Hop Rod' was "…extremely safe and harmless and of tremendous entertainment value."