'James Watt 1788 Double-Action Sun-and Planet Engine', 1797.
© Science Museum / Science & Society Picture Library
This rotative steam engine was designed and built by James Watt (1736-1819) and Matthew Boulton (1728-1809). Watt was a Scottish engineer and inventor at the forefront of the development of steam engines. Boulton was Watt's busines partner. In 1775 they established a partnership designing and making components for steam engines at Soho, near Birmingham.