Who improved the steam engine?

The Watt steam engine (alternatively known as the Boulton and Watt steam engine) was the first type of steam engine to make use of a separate condenser. It was a vacuum or "atmospheric" engine using steam at a pressure just above atmospheric to create a partial vacuum beneath the piston. read more

James Watt, a British inventor, improved the steam engine in the eighteenth century. In 1763, James Watt began his improvements on the Newcomen steam engine. Watt was a technician at the University of Glasgow. read more

In fact, the concept of a steam engine pre-dates modern engines by a couple thousand years as mathametician and engineer Heron of Alexandria, who lived in Roman Egypt during the first century, was the first to describe a rudimentary version he named the Aeolipile. read more