1720 0 APPLETONS' CYCLOPEDIA OF TECHNICAL DRAWING. EMBRACING The Principles of Construction AS APPLIED TO PRACTICAL DESIGN. WITH NUMEROUS ILLUSTRATIONS OF TOPOGRAPHICAL, MECHANICAL, ENGINEERING, EDITED BY W. E. WORTHEN, C. E. NEW YORK: D. APPLETON AND COMPANY, 1, 3, AND 5 BOND STREET. 1892. PREFACE. "Ar the suggestion of the publishers, this work was undertaken to form one of their series of dictionaries and cyclopædias. In this view, it has been the intention to make it a complete course of instruction and book of reference to the mechanic, architect, and engineer. It has not, therefore, been confined to the explanation and illustration of the methods of projection, and the delineation of objects which might serve as copies to the draughtsman, matters of essential importance for the correct and intelligible representation of every form; but it contains the means of determining the amount and direction of strains to which different parts of a machine or structure may be subjected, and the rules for disposing and proportioning of the material employed, to the safe and permanent resistance of those strains, with practical applications of the same. Thus, while it supplies numerous illustrations in every department for the mere copyist, it also affords suggestions and aids to the mechanic in the execution of new designs. And, although the arranging and properly proportioning alone of material in a suitable direction, and adequately to the resistance of the strains to which it might be exposed, would produce a structure sufficient in point of strength for the purposes for which it is intended, yet, as in many cases the disposition of the material may be applied not only practically, but also artistically, and adapted to the reception of ornament, under the head of Architectural Drawing, the general characteristics of various styles have been treated of and illustrated, with brief remarks on proportion and the application of color." . . . 1857. Since its first publication, this work has been subjected from time to time to revision. It has now been deemed necessary to almost entirely rearrange and rewrite it; to add largely to the subject-matter and to the illustrations, introducing examples of later practice and experience; to extend the scope of the work, and make it more nearly a cyclopædia of drawing and design. There are no changes in the principles of projection as applied to drawing, and no marked improvement in drawing-instruments; but in the present practice finished drawings in shade and color are exceptional. It is sufficient, for almost every purpose, for the draughtsman to make accurate projections with pencil on paper, and trace them afterward on cloth. The pencildrawings can be readily altered or amended, and, where there are many repe |