PRACTICAL BOOK OF GARDEN ARCHITECTURE 



ways be depended upon to afford a satisfactory 

 water supply, it will be necessary to have a tank 

 large enough to store a quantity for use in emer- 

 gency. The big water tank may be at the top of the 

 windmill, or in the house or barn. No matter where 

 it is, it must be so arranged that the bottom will be 

 sufficiently elevated to distribute the water freely 

 to all parts of the house. To have the tank suffi- 

 ciently elevated, and of satisfactory size and 

 strength, to supply water for a large country estate 

 may prove a difficult problem. In order to realize 

 just how serious this problem may be, I will state the 

 facts and figures given to me when I consulted an 

 expert authority. 



The water which fills a ten-thousand-gallon tank 

 weighs eighty-three thousand pounds. Ten thou- 

 sand gallons for a family (and stock), using five hun- 

 dred gallons a day, will last only twenty days. The 

 support for eighty-three thousand pounds must, of 

 course, be an adequate one. In every case the total 

 weight of water and tank must be provided for. As 

 to the strength of the tank, we have to remember 

 that water exerts a bursting pressure tending to 

 disrupt the side walls. This pressure ranges from 

 nothing at the water level to a maximum at the 

 bottom. If the bottom is ten feet below the level of 



the water, there will be a bursting pressure outward 



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