312 



Introduction to the Study of Science 



TABLE OF STEAM PRESSURES AND TEMPERATURES 



means that steam has a temperature of 397 F. which is the 

 boiling temperature of water at this pressure. Its temperature 

 may be increased by superheating. The volume of steam at this 

 pressure, 1.9 cubic feet, shows what tremendous capacity a 

 unit of steam of this temperature has and gives up in doing work 

 in reaching the volume which it has at atmospheric pressure. 

 Even this volume is increased by tne low pressure turbine .which 

 gets energy out of steam at a pressure far below that of the 

 atmosphere. Again we have an illustration of the way in which 

 man controls natural forces for his own needs and purposes. 



139. Industrial uses of different boiling temperatures. 

 Knowledge of the different boiling or vaporizing temperatures of 



