ki'.sri.rs <>K VAKIA TION IN n.rinrrv OK MKTAL.
The Tables seen on page ^76 show the difference in chill by reason of ct hot " and ct dull " poured iron, in test bars \}^ inch diameter east on end. It will be noticed that the fluidity of the hottest poured bar in Table Sj was but four inches, and the dullest one, one inch, a difference of three inches, but this was stiffi • eient to make a difference in the chill of live-sixty fourths of an inch, and this was the same iron poured out of the same ladle. A chemical analysis of the iron charged in the cupola and that obtained in the
test bars is also given in Table S2. In* Fig. 70, K shows the fracture of the hot-poured bar, and P the fracture of the dull-poured one, from which a good realization can be received of the effects different, degree's of fluidity can cause in giving different depths of poured from the same the Tables,
chill from the same iron
ladle and which is forcibly shown by
In the Table we find a difference of .078 inch in the ehill of tin* two ^'. -inrh bars which were poured out of tin* same hand ladle holding about fifteen pounds of metal. The first bar was poured as soon as the metal was carried to the " floor/' and the second bar three minutes later. Here we find there is a difference in chill of .oy.s, due to difference in fluidity of metal, or in roui'li futures -^ inch, as seen at V and S, Fig. 70.ny sparks, which is the chief characteristic phenomenon of hard iron and cannot be better explained than in the language of Tomlinson, who says: