PHYSIC AT, TESTS FOR THE BLAST-FURNACE, ETC. 509 quickly, as it does, strike the under part of this cup, an explosion could occur, making the iron fly in all directions. By the plan devised such accidents are prevented. FIG. Iig.—PLAN OF MOULD BOARD. FIG. 12O,—CLAMP, CHILL AND MICROMETER. FIG. 121.—SECTION OF MOULD. In cases where the fluidity and chill tests are not desired, and a plain round test bar only is wanted (which, for general purposes, will serve many ends), a plain round pattern, as at L, Fig.n8, page 507, which in the be easily done .t two minutes.