APPENDIX TO CHAPTER UV.—TESTING FUSION. 417
furnace, etc., as such, would melt the faster. The cut at Fig. 87 shows the exact appearance of the specimen as it was taken out of a crane ladle bath of molten metal, just as the chill end V was about to disappear entirely, and which we have found in all cases to melt away five to ten minutes faster than the gray end X. As the question of encouraging the manufacture of chilled or sandless pig by the blast furnaceman, which this work advocates, is an important one, the author would advise all to try this experiment, and in doing so many will find themselves surprised at the rapidity with which the chill or body hardened end melts, compared to the gray or soft end of the test specimen. In using this device, some judgment will have to be used as to the size of the test roll and of the ladle for its immersion. For a roll of two to three inches diameter a one thousand pound ladle or larger will be necessary, but rolls about one inch in diameter can often be melted down in a bull ladle holding two to three hundred pounds of iron, before the metal would get too dull. These rolls are well made, about twelve inches long, and are secured by the end of the rod seen curved around it tightly in the center. All sand and scale should be well filed or ground off from the sand end of the roll so as to have it free from foreign matter, similar as in the chilled or hardened end, to make conditions alike in each end as far as possible. Another plan for testing fusion is given on pages 231 and 314.
FT(J. 88.—COMPARATIVE FUSION TEST MOLD.esigned for these tests is shown in Fi<.(s. Sy and KS, thr former figure, shows a three-quarter-iurh rod in the hands of a moulder bein^ held over a ladle that, holds in its end a casting made in the mould .seen at Fi#. HH, The upper half S was all y;reen sand3 per cent, of sulphur I