FOURTH EDITION, Thoroughly Revised. Two Volumes. 36s. net. _With Additional Chapter on The Electric Smelting of Steel._ =THE METALLURGY OF STEEL.= BY F. W. HARBORD, ASSOC.R.S.M., F.I.C., AND J. W. HALL, A.M.INST.C.E. THIRD EDITION, Revised and Enlarged. With many new Plates. 16s. net. =THE METALLURGY OF IRON.=