Excerpt from Coal Mining Kinks: Compiled From the Regular Issues of Coal AgeThis difficulty may be overcome by sharpening the drill as shown in Fig. L, where, it will be seen, the corners have been turned back so that the cutting edge assumes a curved outline. Such a drill point as this will not wedge in ordinary cracks and will thus prevent sticking.About the PublisherForgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.comThis 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.