Excerpt from Manual of the Principal Instruments Used in American Engineering and Surveying, Manufactured by W. And L. E. GurleyWe have usually made our needles about one twentieth of an inch broad and one third as thick, parallel from end to end, the north and south poles being distinguished from each other, by a small scollop on the north end.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.