Beam engine
（重定向自Beam pump）
![A Watt engine: showing entry of steam and water](/Images/godic/202412/23/Watt77832739.png")
![The cast-iron beam of the 1812 Boulton & Watt engine at Crofton Pumping Station – the oldest working, in situ example in the world](/Images/godic/202412/23/Uk-crofton-pumping-station-beam-gallery2740.jpg")
![The remains of a water-powered beam engine at Wanlockhead](/Images/godic/202412/23/Wanlockhead_Beam_Engine2740.jpg")
![A small rotative beam engine, built in 1870 by Thomas Horn to a design by James Watt. The crank is visible at the front, the flywheel part-hidden by the engine. (Originally installed in a waterworks in Ashford, now operational and preserved at the Bredgar and Wormshill Light Railway.)](/Images/godic/202412/23/Thomas_Horn_Beam_Engine2740.JPG")
A beam engine is a type of steam engine where a pivoted overhead beam is used to apply the force from a vertical piston to a vertical connecting rod. This configuration, with the engine directly driving a pump, was first used by Thomas Newcomen around 1705 to remove water from mines in Cornwall. The efficiency of the engines was improved by engineers including James Watt who added a separate condenser, Jonathan Hornblower and Arthur Woolf who compounded the cylinders, and William McNaught (Glasgow) who devised a method of compounding an existing engine. Beam engines were first used to pump water out of mines or into canals, but could be used to pump water to supplement the flow for a waterwheel powering a mill.