Excerpt from An Essay on Magnetic Attractions, and on the Laws of Terrestrial and Electro Magnetism: Comprising a Popular Course of Curious and Interesting Experiments on the Latter Subject, and an Easy Experimental Method of Correcting the Local Attraction of Vessels on the Compass in All Parts of the World In the course of these experiments I was so fortunate as to fall upon an easy practical mode of correction, wholly independent of calculation; I also discovered certain magnetic laws which seemed to me likely to pave the way to a' mathematical theory of magnetism. 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.