Excerpt from Valves and Valve-Gearing: A Practical Text-Book for the Use of Engineers, Draughtsmen, and Students The small figures of valves shown on the circumference of valve diagrams illustrate the position of the valves corresponding to various crank positions. It is hoped that they will make the diagrams more readily comprehensible to readers who have not given much previous study to the subject. In the case of slide valves, the and next to the diagram circle represents the front end of the valve that is, the end nearest the crank -shaft. In four-valve engines, the valves nearest the crank-shaft are those drawn adjacent to the diagram, both in the case of steam and exhaust. The arrows denote the direction the valves are moving at the particular position shown: where no arrow appears the valve is in the extreme position of its movement, and has, therefore, no motion at that particq instant. 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.