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Excerpt from Handbook for Machine Designers and Draftsmen As an editor, the author's heart has often ached at the manner in which contributions to technical journals of permanent value and usefulness form a procession to the limbo of forgotten things and benefit none but those under whose eyes they happen to fall at the date of publication. The volume is primarily an effect to rescue from the oblivion of the out of print such contributions as are of direct use in the design of machinery. The search fee material has not, of course, been limited to periodicals but has extended to the transactions of many engineering; societies, wherein information is nearly as effectively burled as In the back numbers of periodicals In filling the gaps that remained after the search was completed, willing friends have come to the author's assistance. Not only is this the way in which this volume has been prepared, but the author is convinced that it is the only way, and, more than this, that there should be deliberate co-operation between contributors, editors and collectors, with efforts focused on books of this character as the ultimate outcome. To be more specific, the author is under no delusions regarding the many things that should be between these covers but that are not. nor of those others of which the data presented are inadequate but, now that a place has been provided for the preservation of information of the sort here gathered together, he hopes that increased activity in (he preparation and the publication of such information. will follow. Hf will certainly be glad to do his part toward the incorporation of such information is future editions. Assistance may be rendered in other ways than by preparing contributions Wide as the search has been, it is cot possible that all of the articles and papers that contain desirable data have been discovered. Those who know of such sources of Information are invited to forward memoranda of the places where they may be found. Due credit to those who have supplied material will be found scattered through the volume From the many who have given willing help it is almost invidious to make selection*, but the author feels that it would be an injustice not to make special mention of Mr J. A, Brown, Mr. Axel Pedecaen and Prof. J. B. Peddle. 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.

This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work. This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.