Excerpt from The Mutual Inductance of a Circle and a Coaxial Single Layer Coil the Lorenz Apparatus and the Ayrton-Jones Absolute Electrodynamometer This problem of finding the mutual inductance of a circle and a coaxial single layer winding was first solved by Lorenz.1 Assuming that the current was uniformly distributed over the surface of the cylinder forming a current sheet he integrated over the length of the cylinder the expression for the mutual inductance of a circular element and the given circle. This expression is an elliptic inte gral. Lorenz reduced the integrated form to a series and gave the following formula for the mutual inductance of the disk and solenoid of what is now called the Lorenz apparatus. He called it, however. 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.