The Whitbread Engine preserved in the Powerhouse Museum in Sydney, Australia, built in 1785, is one of the first rotative steam engines ever built, and is the oldest surviving. A rotative engine is a type of beam engine where the reciprocating motion of the beam is converted to rotary motion, producing a continuous power source suitable for driving machinery. This engine was designed by the mechanical engineer James Watt, manufactured for the firm Boulton and Watt and originally installed in the Whitbread brewery in London, England. On decommissioning in 1887 it was sent to Australia's Powerhouse Museum (then known as the Technological, Industrial and Sanitary Museum) and has since been restored to full working order. History The engine was ordered by Samuel Whitbread in 1784 to replace a horse wheel at the Chiswell Street premises of his London brewery. It was installed in 1785, the second steam engine to be installed in a brewery, and enabled Whitbread to become the largest brewer in Britain. The horse wheel was retained for many years, serving as a backup in case the steam engine broke down...