WATER TOWERS AND GARDEN DENS 



pump, the filling of the water reservoir and other 

 demands are done in the same manner as with the 

 other engines. The pneumatic tank system need not 

 be considered where the means of supply relate to 

 the filling of the tower tanks elevated at some dis- 

 tance from the ground and serving as a decidedly 

 ornamental garden feature in connection with their 

 usefulness. In the pneumatic system no elevated 

 tank is required, as it can be situated in connection 

 with the pump and engine in the cellar or barn or 

 in any out-of-the-way place where there is little 

 danger of freezing. This is the system as it was 

 explained to me when I gave it thorough investiga- 

 tion: "The pressure is obtained by forcing the 

 water to be used into a heavy steel tank halving no 

 air outlet. As the water is pumped into this tank 

 the air is compressed in proportion to the increase 

 in the volume of water. The service water outlet is 

 at the bottom, and the tank is so designed that the 

 pressure is sufficient to raise the required amount of 

 water to the desired height as needed. ' ' There have 

 been some complaints of this system because of pos- 

 sible leakage ; unless an expensive tank is used that 

 has been very carefully manufactured by skilled 

 workmen, it will prove a difficult matter to construct 

 an air-tight tank that will not leak when the con- 

 tained air is crowded into a continually decreasing 



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