Excerpt from The Waterbury Book of Alloys: Supplement The metal itself is extremely sensitive to chemical as well as mechanical conditions and unless care is exercised in every possible direction disappointment. In the final results is inevitable. In many instances, even when the greatest care is taken with the melting and pouring Operations, the result ing castings will be, found to be defective. These results in general may be charged to changes in atmospheric condi tions, as well as to some unintentional oversight in the melting or pouring operations. Only the best grade of metals should be used for the manufacture of nickel and its alloys which are to be used for rolling mill purposes. The copper used may be either lake or electrolytic but, in no instance should that grade of copper known as casting copper be employed. A tough, long-grained grade of spelter practically free from lead or other impurities will be found to give satisfactory results. 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.