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ELEMENTARY SCIENCE 



Water-power may be defined as power derived from 

 falling water and converted (by means of motors) into 

 useful work. A motor is any apparatus which changes 

 (transforms) one form of energy 

 into another. Steam and gaso- 

 lene engines, windmills, and 

 electric dynamos, as well as 

 water-wheels, are forms of mo- 

 tors. 



It is quite simple to compute 

 the amount of power which 

 may be generated by water at 

 a given point. The number of 

 pounds of water that flows in a 

 given time is multiplied by the 

 number of feet of the fall. This 

 gives the theoretical amount of 

 power. From this amount, of 

 course, deductions must be 

 made, for there is always con- 

 siderable loss of power in the 

 processes of transformation and 

 transmission. By transmission 

 is meant the sending of the 

 power. This may be done by 

 geared shafts, or by belts, or, 

 in the case of electricity, by 

 means of wires. 



The power-plant at the famous Keokuk dam illustrates 

 quite simply the most modern and scientific method of 

 getting power from falling water. This is the turbine 

 method (turbo, whirl). In a turbine motor the falling 



FIG. 31. The turbine in action. 



