Excerpt from Drill Jigs: Principles of Design, Examples From Practice, Dimensions of Jig Bushings In the third place, accuracy is Often attained only by the use of jigs. There are certain classes Of work which could not be finished at all within the limits Of accuracy demanded, if jigs Of some sort were not used.. 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.