Excerpt from Transactions of the International Engineering Congress, 1915: Metallurgy, Session Held Under the Auspices of American Society of Civil Engineers, American Institute of Mining Engineers, the American Society of Mechanical Engineers, American Institute of Electrical Engineers, the Society of Naval Architects and Marin The variations in the properties of steel castings are due (1) to variations in the composition of the steel, (2) to the annealing or heat treatment to which the steel is subjected, and (3) to the soundness of the casting. The last of these may be summarized in the familiar saying, a casting is always a cast ing, by which the initiated mean that it may always con tain hidden blow-holes or shrinkage cavities that cause or aid its failure when least expected. The gases that are liberated from solidifying steel, of course, cause blow-holes in ingots as well as in castings, but by the time the ingot is reduced to the rolled or forged shape, these holes are at least closed up, if not partially welded - and they are generally so located as to be least harmful to the finished piece. In the case of castings, the gas from the metal and the steam and gas set free from the sand mould may cause blow-holes that can not be detected by surface inspection of the piece. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.