ELEMENTS OF GEOMETRY AND TRIGONOMETRY, FROM THE WORKS OF Adrien Marie. A. M. LEGENDRE. REVISED AND ADAPTED TO THE COURSE OF MATHEMATICAL INSTRUCTION IN BY CHARLES DAVIES, LL. D., AUTHOR OF ARITHMETIC, ALGEBRA, PRACTICAL MATHEMATICS FOR PRACTICAL Men, OF DIFFERENTIAL AND INTEGRAL CALCULUS, AND SHADES, NEW-YORK: PUBLISHED BY A. S. BARNES & CO., CINCINNATI: H. W. DERBY & CO. 1857.14 Mr. of Roger Brown Ibelewith, Ey of Sporerpheed 11843 DAVIES' Math 50863.50 COURSE OF MATHEMATICS Babies' First Lessons in Arithmetic-For Beginners. Babies Arithmetic-Designed for the use of Academies and Schools. Key to Davies' Arithmetic. Babies' University Arithmetic-Embracing the Science of Numbers and their numerous Applications. Bey to Babies' University Arithmetic. Davies' Elementary Algebra-Being an introduction to the Science, and forming a connecting link between ARITHMETIC and Algebra. Key to Davies' Elementary Algebra. Davies' Elements of Geometry AND Trigonometry, with APPLICATIONS IN Davies' Practical Mathematics for Practical Men-Embracing the Principles of Drawing, Architecture, Mensuration, and Logarithms, with Applications to the Mechanic Arts. Babies' Bourdon's Algebra-Including STURM'S THEOREM-Being an abridg ment of the Work of M. BOURDON, with the addition of practical examples. Babies' Legendre's Geometry AND Trigonometry-From the works of A. M. Babies' Surveying-With a description and plates of the THEODOLITE, COM PASS, PLANE-TABLE, and LEVEL; also, Maps of the TOPOGRAPHICAL SIGNS adopted by the Engineer Department-an explanation of the method of surveying the Public Lands, Geodesic and Maritime Surveying, and an Elementary Treatise on NAVIGATION. Davies' Descriptive Geometry-With its application to SPHERICAL PROJEO TIONS. Babies' Shades, Shadows, and Linear Perspective. Babies' Analytical Geometry-Embracing the EQUATIONS OF THE POINT AND Babies' Differential and Integral Calculus. Babies' Logic and Utility of Mathematics. ENTERED according to Act of Congress, in the year one thousand eight hundred and fifty-one, by CHARLES DAVIES, in the Clerk's Office of the District Court of th United States for the Southern District of New York. PREFACE. IN the preparation of the present edition of the Geom etry of A. M. LEGENDRE, the original has been consulted as a model and guide, but not implicitly followed as a standard. The language employed, and the arrangement of the arguments in many of the demonstrations, will be found to differ essentially from the original, and also from the English translation by DR. BREWSTER. In the original work, as well as in the translation, the propositions are not enunciated in general terms, but with reference to, and by the aid of, the particular diagrams used for the demonstrations. It is believed that this departure from the method of Euclid has been generally regretted. The propositions of Geometry are general truths, and as such, should be stated in general terms, and without reference to particular figures. The method of enunciating them by the aid of particular diagrams seems to have been adopted to avoid the difficulty which beginners experience in comprehending abstract proposi tions. But in avoiding this difficulty, and thus lessening, at first, the intellectual labor, the faculty of abstraction, which it is one of the primary objects of the study of Geometry to strengthen, remains, to a certain extent, un improved. |