ON THE CORROSION OF METALS.
357steel series, and in course of the research examined some recent varieties of steel. The metals were mostly selected from standard samples, and some of the more modern steels were prepared to the Author's specifications by Mr. R. A. Hadfield, Assoc. M. Inst. C.E.The metals operated upon were large rolled wrought-iron bars, and wrought-iron hammered shafts, Bessemer steel and Siemens steel forged shafts; also large bars of soft Bessemer steel, hard Bessemer steel, soft Siemens steel, hard Siemens steel, soft caststeel, hard cast-steel, aluminium steel, nickel steel, chromium steel, silicon steel, and copper steel. Experiments were also made on rolled plates of wrought-iron, soft Bessemer steel, soft Siemens steel, hard Siemens steel, and soft cast-steel. The chemical composition and general physical properties, etc., of the metals are given in the Appendix in Tables I, 11, and Set I, Table 111, Set 11, Table VIII. The various metals were prepared in the form of bars 38 and 32 inches in diameter, and some were forged shafts 43 inches and up to 59 inches in diameter. The plates were & inch thick machined to ths dimensions given in Fig. 6. In the whole of the experiments the metals were perfectly bright. The observations were divided under three heads :-(l) Experiments on the influence of tensile stress on corrosion; (2) Experiments on the influence of torsional stress on the corrosion of metals in sea-water ; (3) Experiments on the influence of flexion stress on corrosion. SET I. INFLUENCE OF TENSILE STRESS ON CORROSION.-METHOD OF EXPERIMENTATION.