34$ METALLURGY OF CAST IRON. A third form, not completed in time for illustration purposes, has a ball and socket joint which allows the tip to stand out at any angle. A movable shield lined with asbestos protects the hand. FIG. 67.—APPARATUS FOR DETERMINING THE MELTING POINT OF CAST IRON — SIDE VIEW. "Fig. 65 shows two of the styles of the pyrometer, and Fig. 66 the method of using the angular form. In the terminal "box are placed the connections which allow wires of any convenient length to run through the handle and connect with the galvanometer. The galvanometer itself is a ' D'Arsonville, speciallyuld soon be an end to this expensive thermo-couple. The long porcelain tube which protects it when used in kilns is worse than useless in a ladle full of metal, and so at the suggestion of the writer the Pittsburg representatives, the Vulcan Mfg. Co. set about to remedy the matter and devise some protective cover which would allow experiments of this kind to be carried out readily. The outcome, while not having the advantage as yet of an extended period of trial, was nevertheless so happy a solution that it is presented, for the first time, with the hope that much of value may be learned from it, not only in our daily work but also in connection with the many intricate problems still before us which await solution at the hands of those willing- to give their time and energy to such an exacting study.