Transcriber’s Note When italics were used in the original book, the corresponding text has been surrounded by _underscores_ except in the case of single letter variables used in the Notes section, where the italics were not represented. Mixed fractions have been displayed with a hyphen between whole number and fraction for clarity. Superscripted characters are preceded by ^ and when more than one character is superscripted, they are surrounded by {}. This book uses some unusual characters, such as those representing the constellation Aries (♈) and Libra (♎). These characters may fail to display correctly if the font you are using does not support them. Some corrections have been made to the printed text. These are listed in a second transcriber’s note at the end of the text. [Illustration: MARY SOMERVILLE J. COOPER S^c. ] ON THE CONNEXION OF THE PHYSICAL SCIENCES. BY MARY SOMERVILLE, AUTHORESS OF ‘MECHANISM OF THE HEAVENS,’ AND ‘PHYSICAL GEOGRAPHY.’ --------------------- “No natural phenomenon can be adequately studied in itself alone—but, to be understood, it must be considered as it stands connected with all Nature.”—BACON. --------------------- Ninth Edition, completely Revised. LONDON: JOHN MURRAY, ALBEMARLE STREET. 1858. _The right of Translation is reserved._ LONDON: PRINTED BY W. CLOWES AND SONS, DUKE STREET, STAMFORD STREET, AND CHARING CROSS. This Book is Dedicated TO HER DEAR CHILDREN, BY THEIR AFFECTIONATE MOTHER, MARY SOMERVILLE. _Florence, Nov. 1, 1858._ CONTENTS. INTRODUCTION Page 1 SECTION I. Attraction of a Sphere—Form of Celestial Bodies—Terrestrial Gravitation retains the Moon in her Orbit—The Heavenly Bodies move in Conic Sections—Gravitation Proportional to Mass—Gravitation of the Particles of Matter—Figure of the Planets—How it affects the Motions of their Satellites—Rotation and Translation impressed by the same Impulse—Motion of the Sun and Solar System 4 SECTION II.