ELEMENTS OF DRAWING AND MENSURATION APPLIED TO THE MECHANIC ARTS. BY CHARLES DAVIES, LL.D., AUTHOR OF FIRST LESSONS IN ARITHMETIC, ARITHMETIC, ELEMENTARY ALGEBRA, PUBLIC NEW YORK: PUBLISHED BY A. S. BARNES & CO., No. 51 JOHN STREET. 1846. MN THE NEW YORK ASTOR, LENOX AND R 1936 L Replacing exppy 288579 Entered according to Act of Congress, in the year 1846, BY CHARLES DAVIES, In the Clerk's Office of the District Court of the United States for the Southern District of New York. Stereotyped by RICHARD C. VALENTINE, New York. C. A. ALVORD, Prüfter, Corner of John and Dutch stre PREFACE. THE design of the present work is to afford an elementary text-book of a practical character, adapted to the wants of a community, where every day new demands arise for the applications of science to the useful arts. There is little to be done, in such an undertaking, except to collect, arrange, and simplify, and to adapt the work, in all its parts, to the precise place which it is intended to fill. The introduction into our schools, within the last few years, of the subjects of Natural Philosophy, Astronomy, Mineralogy, Chemistry, and Drawing, has given rise to a higher grade of elementary studies; and the extended applications of the mechanic arts call for additional information among practical men. To understand the most elementary treatise on Natural Philosophy, or the simplest work on the Mechanic Arts, or even to make a plane drawing, some knowledge of the principles of Geometry is indispensable; and yet, those in whose hands such works are generally placed, or who are called upon to make plans in the mechanic arts, feel that they have hardly time to go through with a full course of exact demonstration. The system of Geometry is a connected chain of rigorous logic. Every attempt to compress the reasoning, by abridging it at the expense of accuracy, has been uniformly and strongly condemned. |