350 SEVENTH REPORT—1837. 
From the preceding examination of the angles obtained from 
specimens of different forms and lengths, it appears that amidst 
great anomalies, there is, taking the mean results, a considerable 
approach to equality, as is more particularly shown from the 
angles of the cylinders and rectangular prisms; and this approach 
would doubtless have been greater and the anomalies less if the 
specimens had always been longer than the wedge. The defect 
in the angle from this cause is evident in the shorter rectangular 
prisms, and has been alluded to before. 
We may assume therefore, without assignable error, that in 
the crushing of short cast iron prisms of various forms, longer 
than the wedge, the angle of fracture will be the same. This 
simple assumption, if admitted, would prove at once, not only 
in this material but in others, which break in the same manner, 
the proportionality of the crushing force in different forms to 
the area; since the area of fracture would always be equal to 
the direct transverse area multiplied by a constant quantity de- 
pendent upon the material. 
The preceding experiments on crushing have been confined 
to one sort of iron, the Carron No. 2, hot and cold blast. The 
results from other irons are given in the following table :— 
