Drawing, dated 22 October 1897, and photograph, showing a beam engine powered by steam. The Newcomen, designed by the English inventor Thomas Newcomen (1663-1729), was the first really practical steam engine, and was built primarily to pump water out of mines. They have a large beam at the top which rocks back and forth and transfers power from a piston moving in a cylinder. Steam enters the cylinder as the piston moves up, it is condensed, and the air presure then forces the piston down.
© Science Museum / Science & Society Picture Library