566 



MACHINES, WORK, AND ENERGY 



during the last century has largely freed civilized man 

 from hard labor. It has made possible the mine, the mill, the 

 factory, the steam ship, and the railroad. It has made man 

 almost the complete master of the physical forces of the world. 

 675. Use of the Earliest Steam Engines. It was just at 

 the beginning of the 18th century (1700) that the steam 

 engine first began to be recognized as a useful machine. 

 During the 18th century, however, practically the only use 

 to which it was put was the pumping of water from the mines 

 of England. Before the invention of the steam engine, many 

 of the coal mines were frequently 

 flooded and some were actually 

 abandoned. 



FIG. 352. Fulton's steamboat, Clermont. FIG. 353. The Rocket. 

 (From Stories of Useful Inventions. Courtesy (From Hoadley's Essentials of 

 of the Century Company.) Physics. Courtesy of Ameri- 



can Book Co.) 



It was not until the closing years of that century that people 

 really began to believe that the steam engine could be used 

 successfully for other purposes. It was about 1785 that the 

 first experimental steamboats were made and not until 1807 

 that Fulton made the Clermont (Fig. 352), the first really 

 successful steamboat. It was not until 1825 that Stevenson 

 constructed the Rocket (Fig. 353), the first successful loco- 

 motive. Today the steam engine is probably doing three- 

 fourths of the work done in the civilized world. 



676. Source of Power in the Steam Engine. When water 

 is changed into steam it expands about 1600 times in volume; 

 a cubic inch of water becomes nearly a cubic foot of steam. 

 If the boiling water and steam are confined in a closed vessel, 



