Cassell and Company, Limited London, Paris & Melbourne 1896 All Rights Reserved [Illustration] PREFACE. The task of giving some account of Maxwell’s work--of describing the share that he has taken in the advance of Physical Science during the latter half of this nineteenth century--has proved no light labour. The problems which he attacked are of such magnitude and complexity, that the attempt to explain them and their importance, satisfactorily, without the aid of symbols, is almost foredoomed to failure. However, the attempt has been made, in the belief that there are many who, though they cannot follow the mathematical analysis of Maxwell’s work, have sufficient general knowledge of physical ideas and principles to make an account of Maxwell and of the development of the truths that he discovered, subjects of intelligent interest. Maxwell’s life was written in 1882 by two of those who were most intimately connected with him, Professor Lewis Campbell and Dr. Garnett. Many of the biographical details of the earlier part of this book are taken from their work. My thanks are due to them and to their publishers, Messrs. Macmillan, for permission to use any of the letters which appear in their biography. I trust that my brief account may be sufficient to induce many to read Professor Campbell’s “Life and Letters,” with a view of learning more of the inner thoughts of one who has left so strong an imprint on all he undertook, and was so deeply loved by all who knew him. R. T. G. _Cambridge, December, 1895._ CONTENTS. CHAPTER PAGE I. EARLY LIFE 9 II. UNDERGRADUATE LIFE AT CAMBRIDGE 28 III. EARLY RESEARCHES--PROFESSOR AT ABERDEEN 38 IV. PROFESSOR AT KING’S COLLEGE, LONDON--LIFE AT GLENLAIR 54 V. CAMBRIDGE--PROFESSOR OR PHYSICS 60 VI. CAMBRIDGE--THE CAVENDISH LABORATORY 73 VII. SCIENTIFIC WORK--COLOUR VISION 93 VIII. SCIENTIFIC WORK--MOLECULAR THEORY 108 IX. SCIENTIFIC WORK--ELECTRICAL THEORIES 148 X. DEVELOPMENT OF MAXWELL’S THEORY 202 JAMES CLERK MAXWELL AND MODERN PHYSICS. CHAPTER I. EARLY LIFE.