Excerpt from The Institution of Mechanical Engineers, Proceedings: October December, 1919 IT is well-known that the Brinell method of testing hardness is unsatisfactory, if applied to very hard substances, such as hardened steel. One source of error is that due to the deformation of the ball. A series of experiments was therefore undertaken with the object of ascertaining how far a modified form of scratch test is applicable to hardened steel. In View of Professor Thomas Turner's established reputation in connexion with scratch testing, the results were submitted to him, and in his Opinion are worthy of publication. The Authors are much indebted to him for help in the drafting of this Note, and also for useful suggestions regarding further work. 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.