METALLURGY OF CAST IRON.
on page 241. In melting these irons A and B to make the castings seen in Figs. 37 and 38, which range from one-eighth to two inches in thickness, all conditions were alike as near as it was possible to have them, so that if the open-grained iron, A, gave a hard casting,
changes in fuel, scrap, blast, weather, etc.— the old excuse — could not be offered as an explanation to befog the true cause A sample of the pig used and sections of the castings made from them the author displayed at the meeting at which this paper was read so that all might see them, and all were invited to take drillings from the specimens and report whether their analyses agreed with those presented in Table 23, in which the letter A represents the analysis obtainedelected samples of pig iron shown in Figs. 37, 38, and 39, coming from two different casts, that are a fair representation of the whole cast or car of iron. If any of the old-school founders were asked to select from these a cast or car of iron to give soft castings, they would pick out iron such as sample A, seen in Figs. 37 and 39, while if they desire to make strong or hard castings they would select such irons as are represented by sample B, seen in Figs. 38 and 39. In fact, if they were asked to use such a cast or car of iron as that represented by B, they would claim that on account of its close grain and the blow-holes seen at D, the iron was hardly fit for sash-weights, let alone to think it of any value to make soft castings.