E-text prepared by Marilynda Fraser-Cunliffe, Stephen H. Sentoff, and the Online Distributed Proofreading Team (http://www.pgdp.net) Note: Project Gutenberg also has an HTML version of this file which includes the original illustrations. See 36691-h.htm or 36691-h.zip: (https://www.gutenberg.org/cache/epub/36691/pg36691-images.html) or (https://www.gutenberg.org/files/36691/36691-h.zip) CONVERSATIONS ON NATURAL PHILOSOPHY, IN WHICH THE ELEMENTS OF THAT SCIENCE ARE FAMILIARLY EXPLAINED. _Illustrated with Plates._ BY THE AUTHOR OF CONVERSATIONS ON CHEMISTRY, &c. WITH CORRECTIONS, IMPROVEMENTS, AND CONSIDERABLE ADDITIONS IN THE BODY OF THE WORK; _Appropriate Questions, and a Glossary:_ BY DR. THOMAS P. JONES, PROFESSOR OF MECHANICS, IN THE FRANKLIN INSTITUTE OF THE STATE OF PENNSYLVANIA. Philadelphia: Published and Sold by John Grigg, No. 9 North Fourth Street. Stereotyped by L. Johnson. 1826. _Eastern District of Pennsylvania, to wit:_ Be it remembered, that, on the twenty-fourth day of April, in the Fiftieth year of the Independence of the United States of America, A. D. 1826, John Grigg, of the said District, hath deposited in this office the title of a book, the right whereof he claims as proprietor, in the words following, to wit: "Conversations on Natural Philosophy, in which the Elements of that Science are familiarly explained. Illustrated with Plates. By the Author of Conversations on Chemistry, &c. With Corrections, Improvements, and considerable Additions, in the Body of the Work; appropriate Questions, and a Glossary: By Dr. Thomas P. Jones, Professor of Mechanics, in the Franklin Institute, of the State of Pennsylvania." In conformity to the Act of the Congress of the United States, entitled "An Act for the Encouragement of Learning, by securing the Copies of Maps, Charts, and Books, to the Authors and Proprietors of such Copies, during the times therein mentioned;"--And also to the Act, entitled, "An Act supplementary to an Act, entitled, 'An Act for the Encouragement of Learning, by securing the Copies of Maps, Charts, and Books, to the Authors and Proprietors of such Copies during the times therein mentioned,' and extending the benefits thereof to the arts of designing, engraving, and etching, historical and other prints." D. CALDWELL, Clerk of the Eastern District of Pennsylvania. PREFACE.