ON THE STEENGTH OF PILLAES OF CAST lEON. 
899 
This pillar broke, dilFerent from the last, by compression of the edge, showing great 
additional strength. 
Note. The last pillar broke by the compression of one of the edges, and the iron 
in these, being harder than that in the thicker parts, would offer greater resistance to 
crushing than in them ; and hence the strength of the pillar would be increased (see the 
experiments in Table VIII.). The part subjected to crushing would in this pillar 
be at a greater distance from the centre of the section than in the others ; and from my 
numerous experiments on the resistances to crushing and to tearing asunder in cast iron, 
it appears that the former is, on the average, about six times as great as the latter. See 
my experiments in the Eeport of the Commissioners on the Application of Iron to Rail- 
way Structures, page 15. From these and other causes the greater strength of a solid 
triangular pillar of cast iron, above one of a circular or square section, may be inferred ; 
a conclusion not without importance in some applications of the metal. 
