XLVIII 



T. W. SEAVER. 



If the height is great compared with the base, p 2 and S, may 

 be neglected, and the stress is parabolic-. 



But, says Professor Pearson, p 2 does not = as we do 

 not know what these internal pressures may be, and if to 

 the parabola or triangle of pressures, we add any system 

 of equilibrated pressures, then the outside pressure remains 

 the same but the internal stresses will be changed. He 

 therefore sums up thus : — (See Fig. 6.) 



