APPLETONS' CYCLOPEDIA OF APPLIED A DICTIONARY OF Mechanical Engineering and the Mechanical Arts, ILLUSTRATED WITH NEARLY FIVE THOUSAND ENGRAVINGS. EDITED BY PARK BENJAMIN, PH. D., LL. B. IN TWO VOLUMES. VOL. I. NEW YORK: D. APPLETON AND COMPANY, 1880. PREFACE. 66 THE present Cyclopædia is not a revision of the well-known "Dictionary of Mechanics," issued by its publishers more than a quarter of a century ago, but is an entirely new work. The amount of matter retained from the Dictionary" bears but an insignificant proportion to the present contents. The plan of the work has been materially changed; not merely so as greatly to increase the number of subjects treated and to group them more logically, but to give a connected view of the chief types of each class of invention, to exhibit clearly their relations to each other and the principles of construction involved in them, and in most cases to present results of their actual working from well-authenticated records. Special efforts have also been directed toward rendering the information given of such practical utility that the work may serve as a trustworthy guide to the engineer and mechanical student in their every-day avocations. To this end, simplified rules have been introduced, with plain examples of their application; graphic methods have been preferred to those involving mechanical demonstration; and facts generally have been combined wherever possible in condensed tabular form. All the principal mechanical inventions and discoveries which have contributed toward the vast progress accomplished during late years in science and the arts-and more particularly those which have attracted the world's attention at the great International Expositions of Vienna in 1873, Philadelphia in 1876, and Paris in 1878-will be found described in these pages. Where the magnitude of a subject has precluded its treatment in detail, ample bibliographical references are supplied, which will direct the reader in the path of closer investigation. The editor gratefully acknowledges his indebtedness to his contributors for the preparation of many important original articles, and for valued counsel. While care has been taken to accord proper recognition to all authorities quoted, special credit is due to the "American Cyclopædia" for illustrations and some few selections from the text of the mechanical and scientific articles. |