In a crowded machinery hall at Birmingham's Thinktank Museum, one of the most intriguing engines is the Leeds-built Fenton, Murray & Wood Hypocycloidal Engine dating from 1802-05, now the third-oldest working steam engine in the world. The museum's Smethwick Engine is the oldest and the second oldest is The Whitbread Engine, built in 1785, which is now in the Powerhouse Museum in Sydney. Designed by Matthew Murray, Thinktank’s hypocycloidal engine employed a novel way of converting reciprocal motion into rotative motion. While William Murdoch had experimented with ‘Sun and Planet Gears’ – often credited to James Watt – as an alternative to using a crank and flywheel, Murray developed a compact 5hp engine using a set of cycloidal gears which delivered much more torque than other similarly powered engines. It was installed new in John Bradley & Company in Stourbridge where it may have driven a small rolling mill.