Excerpt from The Principles of Mechanics: Presented in a New Form The volume now published is Heinrich Hertz's last work. To it he devoted the last three years of his life. The general features were settled and the greater part of the book written within about a year; the remaining two years were spent in working up the details. At the end of this time the author regarded the first part of the book as quite finished, and the second half as practically finished. He had arranged to work once more through the second half. But soon his plans became only hopes, and his hopes were doomed to disappointment. Death was soon to claim him in the prime of his power. Shortly before he died he forwarded to the publishers the greater part of the manuscript. At the same time he sent for me and asked me to edit the book, in case he should not be able to see it through the press. 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.