Steam engines were the first engine type to see widespread use. They were first invented by Thomas Newcomen in 1705, and James Watt (who we remember each time we talk about "60-watt light bulbs" and the such) made big improvements to steam engines in 1769.

Steam engines powered all early locomotives, steam boats and factories, and therefore acted as the foundation of the Industrial Revolution. In this edition of HowStuffWorks, we will see exactly how steam engines work!