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2. In girders having the same total depth (namely 4 inches), and 

 consequently nearly the same deflection, but differing in the depth 

 of metal 



From these experiments, the particulars of which are fully de- 

 tailed, the following facts are elicited : 



1. That in all cases the total resistance at the outer fibre, at the 

 time of rupture, is greater than the tensile strength, 



2. That in girders having the same depth of metal, it increases 

 when the deflection increases ; and 



3. That in girders having the same total depth, and the same de- 

 flection, the resistance is greater when the depth of metal in the 

 beam is greater. 



And it follows that there is an element of strength depending on 

 the depth of metal in connexion with the deflection ; or in other 

 words, dependent on the degree of flexure to which the metal form- 

 ing the beam is subjected. 



The author next proceeds to examine the law under which this 

 resistance varies ; and considering the total resistance in the solid 

 beam to be composed of two resistances, one being constant and 

 due to the tensile strength, and the other variable and depending on 

 the depth of the metal in connexion with its deflection, the experi- 

 ments indicate that the resistance to flexure varies, throughout all 



2K2 



