ABSTRACT
James Watt’s invention of the steam engine was the most important development in the use of energy in a millennium. Initially applied to manufacturing, it provided a source of energy that could replace human or animal muscles, did not depend on having suitable rivers available, and did not depend on whether the wind was blowing. Richard Trevithick’s extension of Watt’s steam engine to develop the steam locomotive provided an entirely new form of transportation. These two applications of the steam engine-to manufacturing and to transportation-place a sharp dividing line between medieval and modern technologies.
