Boulton and Watt's 'Sun and Planet' engine, 1797.

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. He was at the forefront of the development of steam engines and described a steam locomotive in one of his patents. Boulton was Watt's busines partner. In 1774 they established a manufactory of steam engines in Soho, near Birmingham.