Water Power 



69 



Much of the work that water is able to perform for us is 

 due to the pressure it exerts. The experiments which follow 

 will show the existence of this pressure and in what ways it is 

 exerted. 



THE MUSCLE SHOALS DAM 



Wide World 1'hoto. 



When fully developed the Muscle Shoals power plant will be one of the greatest in the 



United States. 



Experiments to Show Water Pressure. Place a thin piece 

 of cardboard about three inches square over the bottom of a 

 common lamp chimney. Holding it firmly in place with the hand, 

 lower the chimney about one-fourth its length into a dish of 

 water. Then remove the hand from the cardboard. The upward 

 pressure of the water will hold the cardboard in place. Gradually 

 pour water into the chimney. When the level of the water in 



