OF IRON BEAMS. 459 



was doubtless the stronger, as it had more 

 matter in the bottom rib, and they both broke 

 by tension, or by drawing asunder the bottom 

 part : which had indeed been the case with 

 every beam we had tried. 



All the preceding experiments were made on 

 beams cast on their side from iron, of which 

 the following is a description. 



Mixtnre. 



} of Blaina, No. 2,? 



i of Blaina, No. 3,S^^^^' 



J of W S S, No. 3, Shropshire. 



This mixture is a strong iron, and therefore 

 well suited for beams. 



VIJ. EXPERIMENT. 



This was on a beam from the same model as 

 that in experiment 4, it was cast erect, but 

 upside down as usual, and therefore ought not 

 to be compared with the preceding ones. 

 Distance between supports as before. 



DlmeiuioM of Motion in inchet. H^ 



Thickness at A = .30. 

 „ „ B= .87. 

 „ „ C = .425. 

 FE = 2.28. 

 DEz: .53. 

 Area of the above section = 2.98 ins. ir 

 3 M 2 



