James Watt was a Scottish inventor and engineer. While working as an instrument maker at the University of Glasgow, he was once called in to repair a lab model of Newcomen’s steam engine. During the repair, he noticed how little work the engine was capable of. He realized that there was an ample room for improving the efficiency of the engine.

To reduce the energy loss, Watt decided to redesign the engine skipping the cooling water injection step, and including a condenser intended to collect the condensed steam so that it is available for expansion in the next cycle. This was a simple yet ingenious design change that brought significant efficiency improvement. By the end of 1765, a twenty nine year old James had built his first small-scale steam engine featuring a separate condensing chamber and a steam jacket.

James Watt would go on to bring about further improvements while upscaling the design to build a commercial steam engine. The Watt steam engines soon replaced most of the human and animal labor in coal mines. As these new engines found their way into more and more applications, the Industrial Revolution kick started. For his contributions, James Watt is still regarded as one of the most important figures behind the Industrial Revolution.