Download or read book United States Magnetic Tables and Magnetic Charts for 1915 (Classic Reprint) written by Daniel L. Hazard and published by Forgotten Books. This book was released on 2017-11-23 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt: Excerpt from United States Magnetic Tables and Magnetic Charts for 1915 It is customary to represent graphically the results of a magnetic survey by means of maps on which lines are drawn through all places having the same value of a particular magnetic element. Maps showing the lines of equal declination, inclination, and intensity are called, respectively, isogonic, isoclinic, and isodynamic charts. In the preparation of such charts all of the results must be reduced to a common epoch by means of the secular change data derived from repeated observations at selected stations. 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.