128 



TOWERS AND TANKS FOR WATER-WORKS, 



must be a horizontal reaction H at the top and at the bottom 

 of the post, in the same vertical plane as the post, i.e., in a 

 diametral plane. 



If the inclination is expressed in rectangular co-ordinates 



and 



When there is a change in the inclination of the post there 

 must be a horizontal reaction in a diametral plane at the point 

 of change. Let H f be this reaction. Then 



<{>, 



or 



ZT' Wi 



LJ- Vr \ , / , 



Stresses Resulting from the Horizontal Thrust at the Top 

 of the Posts. At the top of each post there is a radial inward 



thrust whose value has been determined from the vertical load 

 and inclination of the post. Let H be the amount of this thrust. 



