JAMES CLERK MAXWELL AND MODERN PHYSICS by R T. GLAZEBROOK. Originally published in 1895. PREFACE: THE task of giving some account of Maxwells work of describing the share that he has taken in the advance of Physical Science during the latter halt 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 Maxwells 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 dis covered, subjects of intelligent interest. Maxwells life was written in 1882 by two of those who were most intimately connected with him, Pro fessor 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 Campbells Life and Letters, with a view of learn ing 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 include: . PACK On AFTER I. EARLY LIFE 9 II. UNDERGRADUATE LIFE AT CAMBRIDGE ... 28 III. EARLY RESEARCHES-PROFESSOR AT ABERDEEN . 38 ,, IV. PROFESSOR AT KINGS COLLEGE, LONDON LIFE AT GLENLAIR 54 V. CAMBRIDGE PROFESSOR OF PHYSICS ... CO ,, VI. CAMBRIDGE THE CAVENDISH LABORATORY . . 73 VII. SCIENTIFIC WORK COLOUR VISION . . .93 VIII. SCIENTIFIC WORK MOLECULAR THEORY . . 108 j, IX. SCJEXTIFIC WORK ELECTRICAL THEORIES . .148 X. DEVELOPMENT OF MAXWELLS THEORY . . 202. JAMES CLERK MAXWELL AND MODERN PHYSICS. CHAPTER I. EARLY LIFE. ONE who has enriched the inheritance left by Newton and has consolidated the work of Faraday one who impelled the mind of Cambridge to a fresh course of real investigation has clearly earned his place in human memory. It was thus that Professor Lewis Campbell and Mr. Garnett began in 1882 their life of James Clerk Maxwell. The years which have passed, since that date, have all tended to strengthen the belief in the greatness of Maxwells work and in the fertility of his genius, which has inspired the labours of those who, not in Cambridge only, but throughout the world, have aided in de veloping the seeds sown by him. My object in the following pages will be to give some very brief account of his life and writings, in a form which may, I hope, enable many to realise what Physical Science owes to one who was to me a most kind friend as well as a revered master. The Clerks of Penicuik, from whom Clerk Maxwell was descended, were a distinguished family. Sir John Clerk, the great-great-grandfather of Clerk Maxwell, was a Baron of the Exchequer in Scotland from 1707 to 1755 he was also one of the Commissioners of the Union, and was in many ways an accomplished scholar. His second son George married a first cousin, Dorothea Maxwell, the heiress of Middlebie in Dum friesshire, and took the name of Maxwell. By the death of his elder brother . Tames in 1782 George Clerk Maxwell succeeded to the baronetcy and the property of Penicuik, Before this time ho, had become involved in mining and manufacturing specu lations, and most of the Middlebio property had been sold to pay his debts. The property of Sir George Clerk Maxwell de scended in 1798 to his two grandsons, Sir George Clerk and Mr, John Clerk Maxwell...