SEAL. District of Pennsylvania, to wit: BE IT REMEMBERED, that on the twenty-second day of November, in the thirty-fourth year of the independence of the United States of America, A. D. 1809, Hopkins and Earle, of the said district, have deposited in this office the title of a book, the right whereof they claim as proprietors, in the words following, to wit: “ A Plain Elementary and Practical System of Natural Experi. mental Philosophy; including Astronomy and Chronology. By the late Rev. John Ewing, D. D. Provost of the University of Pennsylvania. Being the Course of Lectures delivered by him in that Seminary,(Enlarged and Improved from time to time,) for upwards of twenty years. Illustrated by Copperplate Engravings. The whole carefully Revised and prepared for the Press, with sundry Explanatory and Supplementary Notes; By Robert Patterson, Professor of Mathematics in the said University. With a Biographical Sketch of the Author.” D. CALDWELL, CONTENTS. Page Definition of Natural Philosophy, with rules of philosophi- The Lever The Pulley The Wheel and Axle The Inclined Plane and Wedge The Screw Of Compound Machines Of Friction Equable Motion Accelerated Motion of Bodies descending by Gravity, in vacuo Motion of Bodies in a resisting Medium of Bodies on Inclined Planes of Pendulums of Projectiles of Bodies round a Center 89 92 93 95 96 97 99 101 102 103 104 107 111 115 119 129 Of the Specific Gravities of Bodies Table of the Specific Gravities of sundry Bodies Motion of Incompressible Fluids The Reflexion of Light from Plane Surfaces Refraction of Light through Plane and Spherical Surfaces The Focus of Rays by Refraction Images of Objects by Refraction General Table of the Primary Planets in the Solar System 411 Aspects of the Superior Planets The truth of the Copernican System Distances and Parallaxes of the Planets Elliptic Orbits of the Planets Elements and construction of Solar Tables To find the Latitude of a Place To find the Obliquity of the Ecliptic to the Equator 460 To find the Time of an Equinox To find the Time of a Solstice To find the Length of the Tropical, Periodical, and To find the Eccentricity, with the Aphelion, and Pe- rihelion Distances of the Earth's Orbit To find the Sun's Mean Anomaly for any given Time 467 To find the Sun's Right Ascension To compute the Equation of Time To find the Time of the Day or Night, by the Meri- Other Methods of finding the Apparent Time Time of the Moon's Rising, and Horizontal Moon |