Trevithick's locomotive could pull seventy people along ten miles of railroad tracks. It was powered by a steam engine. A steam engine runs on boiling water. A fire of coal or wood heats the water, and the boiling water makes steam. The force of the steam pushes a piston up and down.
People also put steam engines on boats.
Some of the first steamships traveled the 1807 Steamboat Mississippi River. Instead of turning wheels round and round, the engines turned giant paddlewheels, like the one on this boat. Later on steamships used propellers. Not everyone liked the new ways of traveling. One scientist thought that high speed train travel could make the brains fall out.