Excerpt from Contributions to Terrestrial Magnetism, the Magnetic Dip or Inclination: As Observed at Thirty Important Maritime Stations, Together With an Investigation of the Secular Change in the Direction of a Freely Suspended Magnetic Needle at Twenty-Nine of the StationsThe observations that are discussed in this chapter have been col looted in the Hydrographic Office, during the period elapsed since 1885, with a view of providing for the deduction of values of the rates of secular change of the magnetic inclination for use in bringing forward from one epoch to another the values of the inclination observed in the regions where the stations are situated, and also for use in shifting the lines of equal magnetic inclination published on charts for past epochs to their positions at the present or some future time. The deduced expressions for the secular change of the magnetic inclination have been used in this manner in connection with the preparation of the Chart of the World, lately published by the Hydrographic C¿ice, showing the lines of equal magnetic dip and variation for the year 1897.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.