OP IRON BEAlfifS. 429 



X 

 Weight. Deflection. 



30 - - - - .86 



40 - - - - 1.24 



50 - - - - 1.60 Set .13. 



60 - - - - 2.03 Do. .17. 

 -31(1 70 It broke with this, Ci inches from the 

 fixed end, it being rather thicker near the end. 



WelghU DeflecUon. 



30 - - - - .84 

 40 - - - 1.16 



erw I ^O 5 Set .10, after MTeral miontes it 



Q\j - - - - l,0^ ^became .07. 



60 - - - 1.86 Set .15. 



)8. The preceding experiments were mostly 

 begun with the broad part of the casting upwards 

 to compress the vertical rib ; and when a weight 

 or two had been laid on and the deflexions 

 noted, the piece was turned the other way up, 

 before the elasticity was much injured, and the 

 deflections from the same weights again taken, 

 the rib being now extended. This mode of 

 turning the piece, which was usually done two 

 or three times with the same casting, it being 

 first reduced, if necessary, to its original form, 

 answered better for obtaining the compaiative 

 extensions and compressions by equal weights. 



