STORAGE AND DISTRIBUTION. 



Using equation -^- + ^ as explained, we have 

 29 29 x 071 



= 8'6i + 107, which will give compression '96 ton 

 and tension 'i ton per sq. ft. 



The pressure due to the water is equal to 



iwhl= i x 5 x 10 x io'3 



= 1*43 tons. Combining this with the previous result- 

 ant we have a new resultant which cuts beyond the 



r u u .1 W M 



inner edge of the base, and consequently -r- + -~ 



r\. A 



will give the following results : 



. 

 = 2*5 tons compression and 1*55 tons tension. 



In the same way, the left-hand wall may be con- 

 sidered, and it will be found that, as before, the values 

 of compression and tension for earth and water 

 pressure are within safe limits for concrete walls. 



The illustration also shows the proper methods of 

 construction. A reservoir of this description affords 

 a good opportunity for the use of reinforced concrete, 

 especially in the case of porous rock such as shale. 

 The organic matter and surface soil should be cut 

 away, and the hard bottom exposed and trimmed off 

 level, and this space enclosed by a concrete wall. We 

 will assume the ground falls away corner-wise, and 

 that two sides of the tank are exposed, as shown in 

 figs. 94 and 95. 



The walls lying against the rock would be 6 in. 

 thick at the bottom and 4 in. at the top, and rein- 



