504 THE STRENGTH 



place, by a wedge tearing out from near the 

 neutral line, as was the case in experiment 19. 



In experiment 29, the model of the beam had 

 precisely the same section in its middle as that 

 in experiment 28 ; but the beam was twice the 

 length. If then the strength be inversely as 

 the length, this beam ought to bear half of that 

 in experiment 28. 



In experiment 30, the model had in section, 

 in its middle, the same top and bottom rib, as 

 in the two preceding experiments, with nearly 

 the same thickness of vertical part; but this 

 beam was double the depth of the others ; it 

 was likewise double the length of that in expt. 

 28, and had therefore the same length as that 

 in experiment 29. If then the strength be 

 simply as the depth, as we have before con- 

 cluded, (article 57,) this beam ought to have 

 double the strength of that in experiment 29 ; 

 and if the strength with the same section is 

 inversely as the length, its strength should be 

 the same as that in experiment 28, it being 

 double the length and depth, and in other 

 respects the same. 



The remarks above made respecting experi- 

 ments 28, 29, and 30, will equally apply to 



